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  • 1.
    Abdalla, Lahood
    et al.
    Umeå universitet, Medicinska fakulteten, Wallenberg centrum för molekylär medicin vid Umeå universitet (WCMM). Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Tandläkarutbildning.
    Soltani, Bagir
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Tandläkarutbildning.
    The effect of calcium silicate-based cements on viability and differentiation of human stem cells from the dental apical papilla.: Future aspects in endodontic regeneration.2023Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Introduction:

    Pulp necrosis in immature permanent teeth stops root development and may lead to higher risk of cervical fractures and a challenging treatment. Regenerative endodontic treatment (RET) aims to continue tooth development and implies the use of calcium silicate-based cements, such as Mineral trioxide aggregate (MTA) and Biodentine to seal the root canal. However, its effect on stem cells has been poorly explored. 

    Aims: Examine the effect of two different calcium silicate-based cements on the viability and the odonto-/osteogenic potential of Stem Cells from Apical Papilla (SCAP).

    Material and method: 

    Isolated SCAPs from three healthy donors (donor I, II and III) were used and exposed for different concentration extracts of ProRoot® MTA and BiodentineTM for 21 days. Cell viability was studied using the neutral red cytotoxicity test. Osteogenic differentiation was analyzed by the alkaline phosphatase test (ALP).

    Results: 

    No difference in SCAPs viability was detected by the type of cements used, Biodentine or ProRoot MTA. However, material concentration could be associated with cells cytotoxicity.  Osteogenic differentiation was not based on the type of cement used but the environment conditions (aerobic/anaerobic) and the genetical background.

    Conclusions:

    The type of cement used in RET, Biodentine or MTA, showed similar effect on SCAPs viability and differentiation potential in vitro. Further studies should be performed to analyze their effect -in -vivo.

    Fulltekst (pdf)
    fulltext
  • 2. Abrahamsson, Helene
    et al.
    Eriksson, Lars
    Abrahamsson, Peter
    Häggman-Henrikson, Birgitta
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi. Department of Orofacial Pain and Jaw Function, Malmö University, 205 06 Malmö, Sweden.
    Treatment of temporomandibular joint luxation: a systematic literature review2020Inngår i: Clinical Oral Investigations, ISSN 1432-6981, E-ISSN 1436-3771, Vol. 24, nr 1, s. 61-70Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Objectives: To evaluate the effectiveness of surgical and nonsurgical treatment of temporomandibular joint (TMJ) luxation.

    Materials and methods: This systematic literature review searched PubMed, the Cochrane Library, and Web of Science databases to identify randomized controlled trials on TMJ luxation treatment published between the inception of each database and 26 March 2018.

    Results: Two authors assessed 113 unique abstracts according to the inclusion criteria and read nine articles in full text. Eight articles comprising 338 patients met the inclusion criteria, but none of these evaluated surgical techniques. Three studies including 185 patients concerned acute treatment with manual reduction of luxation while five studies including 153 patients evaluated minimally invasive methods with injection of autologous blood or dextrose prolotherapy for recurrent TMJ luxation. These studies reported that mouth opening after treatment was reduced and that independent of type of injection, recurrences of TMJ luxation were rare in most patients.

    Conclusions: In the absence of randomized studies on surgical techniques, autologous blood injection in the superior joint space and pericapsular tissues with intermaxillary fixation seems to be the treatment for recurrent TMJ luxation that at present has the best scientific support. Well-designed studies on surgical techniques with sufficient numbers of patients, long-term follow-ups, and patient experience assessment are needed for selection of the optimal surgical treatment methods.

    Clinical relevance: Autologous blood injection combined with intermaxillary fixation can be recommended for patients with recurrence of TMJ luxation.

    Fulltekst (pdf)
    fulltext
  • 3.
    Adam, Anushik
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Tandläkarutbildning.
    Carlström, Celine
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Tandläkarutbildning.
    The role of the c-c chemokine receptors (CCR) 2 and 5 during osteoclast differentiation of CCR3-deficient cells2023Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Background: Osteoclasts are the cells responsible for bone resorption and they are formed by the fusion of cells from the monocyte/macrophage lineage. The formation of osteoclasts is dependent on various signaling pathways, including those under the control of chemokines and their receptors. In vitro, the expression of C-C chemokine receptor 3 (CCR3) is upregulated during osteoclastogenesis and the lack of Ccr3 gene (Ccr3-/-) leads to an increased size and activity of osteoclasts. The increased size and activity of the Ccr3-/- osteoclasts correlated with an upregulation of the transcripts from the C-C chemokine receptor 2 (Ccr2) and C-C chemokine receptor 5 (Ccr5) genes. 

    Aim: The aim of this study is to see if the upregulation of Ccr2 and Ccr5 contributes to the phenotypes of Ccr3-/- osteoclasts. 

    Methods: In this study, we used antagonists of CCR2 and CCR5 (RS 504393 and Maraviroc) to investigate the effect of the respective receptor on osteoclastogenesis in Ccr3+/+ and Ccr3-/- cells.  For this experiment we obatianed Bone marrow macrophages (BMMs) from Ccr3+/+ and Ccr3-/- mice for osteoclastformation. tartrate-resistant acid phosphatase (Trap) staining was thereafter added to the cultures to be able to analyze the results visually and statistically.  

    Results: At the concentration of 5μM (RS 504393 ) and 7.5 μM (Maraviroc ) the osteoclastogenesis was inhibited. Lower concentrations than 5μM of RS 504393 and 7.5 μM of Maraviroc, the size of the osteoclasts formed in cultures were significantly bigger than those formed in the controls. Further, this effect was largely independent of the genotype of the cells. In addition, the inhibition of CCR2 with RS 504393 suggest that the number of Ccr3+/+ and Ccr3-/-osteoclasts increased compared to the control groups. 

    Conclusion: The observation that the inhibition of CCR2 or CCCR5 appears to promote osteoclastogenesis implies that the increased expression of Ccr2 and Ccr5 may not underly the phenotypes of Ccr3-/- osteoclasts. This as the osteoclasts became larger overall when antagonists of each receptor were added. 

  • 4.
    Adam, Safa Mohammed
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Tandläkarutbildning.
    Ohlsson, Sofie
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Tandläkarutbildning.
    Quality Assessment of Panoramic Radiographs Performed in Västerbotten County Council2022Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Background: Panoramic radiography provides an overview of the teeth, jawbone and surrounding bony/calcified structures. The examination is, however, challenging to perform without errors. Poor-quality panoramic radiographs can result in misinterpretations, repeated or supplementary examinations, increasing the radiation dose.  

    Aim: To assess the overall quality of a sample of panoramic radiographs performed in Västerbotten county council and to investigate whether the patients’ gender and/or age influence image quality.

    Methods: A total of 274 digital panoramic radiographs were assessed by two observers for the presence of errors, following an assessment protocol. The general image quality was classified and the causes of imaging errors were evaluated.  

    Results: The most common error was turned patient head, and the least frequent was the presence of external artifacts. Only five radiographs were without error (1.8%), 31.4% were adequate, 51.5% poor but diagnosable, and 15.3% undiagnosable. No major differences in image quality were found between gender (P=0.138) or between adults and children (p=0.607). Younger children had a significantly higher incidence of image errors compared to older children (P=0.021). The most common cause of undiagnosable radiographs among adults was incorrect tongue position and among children, movement during exposure.  

    Conclusion: Image quality in panoramic radiographs performed in Västerbotten county council can improve, since more than every seventh radiograph was considered undiagnosable and less than 2% were deemed excellent. It is more challenging to perform panoramic examinations on smaller children. By reducing the number of image errors, retakes and additional radiation dose to the patient can be avoided.  

  • 5.
    Adjez, Timor
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Torshage, Wilhelm
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Comparison of image quality in radiographs acquired with different panoramic machines in Västerbotten2023Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
  • 6.
    Agler, Cary S.
    et al.
    Oral and Craniofacial Health Sciences, UNC School of Dentistry, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States.
    Shungin, Dmitry
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi. Broad Institute of the Massachusetts Institute of Technology and Harvard University, MA, Cambridge, United States.
    Ferreira Zandoná, Andrea G.
    Department of Comprehensive Dentistry, Tufts University School of Dental Medicine, Tufts University, MA, Boston, United States.
    Schmadeke, Paige
    Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States; Biospecimen Core Processing Facility, Gillings School of Global Public Health, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States.
    Basta, Patricia V.
    Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States; Biospecimen Core Processing Facility, Gillings School of Global Public Health, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States.
    Luo, Jason
    Lineberger Comprehensive Cancer Center, School of Medicine, University of North Carolina, NC, Chapel Hill, United States; Mammalian Genotyping Core, University of North Carolina, NC, Chapel Hill, United States.
    Cantrell, John
    Oral and Craniofacial Health Sciences, UNC School of Dentistry, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States.
    Pahel, Thomas D.
    Oral and Craniofacial Health Sciences, UNC School of Dentistry, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States.
    Meyer, Beau D.
    Department of Pediatric Dentistry, UNC School of Dentistry, CB#7450, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States.
    Shaffer, John R.
    Center for Craniofacial and Dental Genetics, School of Dental Medicine, University of Pittsburgh, PA, Pittsburgh, United States; Department of Oral Biology, School of Dental Medicine, University of Pittsburgh, PA, Pittsburgh, United States; Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, PA, Pittsburgh, United States.
    Schaefer, Arne S.
    Department of Periodontology, Institute of Dental, Oral and Maxillary Medicine, Charité—University Medicine Berlin, Berlin, Germany.
    North, Kari E.
    Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States; Carolina Center for Genome Sciences, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States.
    Divaris, Kimon
    Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States; Department of Pediatric Dentistry, UNC School of Dentistry, CB#7450, University of North Carolina-Chapel Hill, NC, Chapel Hill, United States.
    Protocols, methods, and tools for genome-wide association studies (GWAS) of dental traits2019Inngår i: Odontogenesis: methods and protocols / [ed] Petros Papagerakis, Humana Press, 2019, , s. 17s. 493-509Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    Oral health and disease are known to be influenced by complex interactions between environmental (e.g., social and behavioral) factors and innate susceptibility. Although the exact contribution of genomics and other layers of "omics" to oral health is an area of active research, it is well established that the susceptibility to dental caries, periodontal disease, and other oral and craniofacial traits is substantially influenced by the human genome. A comprehensive understanding of these genomic factors is necessary for the realization of precision medicine in the oral health domain. To aid in this direction, the advent and increasing affordability of high-throughput genotyping has enabled the simultaneous interrogation of millions of genetic polymorphisms for association with oral and craniofacial traits. Specifically, genome-wide association studies (GWAS) of dental caries and periodontal disease have provided initial insights into novel loci and biological processes plausibly implicated in these two common, complex, biofilm-mediated diseases. This paper presents a summary of protocols, methods, tools, and pipelines for the conduct of GWAS of dental caries, periodontal disease, and related traits. The protocol begins with the consideration of different traits for both diseases and outlines procedures for genotyping, quality control, adjustment for population stratification, heritability and association analyses, annotation, reporting, and interpretation. Methods and tools available for GWAS are being constantly updated and improved; with this in mind, the presented approaches have been successfully applied in numerous GWAS and meta-analyses among tens of thousands of individuals, including dental traits such as dental caries and periodontal disease. As such, they can serve as a guide or template for future genomic investigations of these and other traits.

  • 7. Ahlgren, Camilla
    et al.
    Molin, Margareta
    Umeå universitet, Medicinsk fakultet, Odontologi, Protetik. Umeå universitet, Medicinsk fakultet, Odontologi.
    Lundh, Thomas
    Nilner, Krister
    Levels of gold in plasma after dental gold inlay insertion.2007Inngår i: Acta odontologica Scandinavica, ISSN 1502-3850, Vol. 65, nr 6, s. 331-4Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    OBJECTIVE: Several studies have reported increased levels of gold (Au) in the blood of patients with dental gold restorations. This study analyzed gold levels in blood plasma before dental gold inlay insertion, 0-12 months after, and 15 years after. MATERIAL AND METHODS: Plasma samples from 9 patients were taken before and 0-10 months after gold inlay insertion. Fifteen years after gold inlay insertion, further blood samples taken from 8 of these patients were analyzed for gold using inductively coupled plasma mass spectrometry. An oral examination was also carried out before and 15 years after gold inlay insertion. RESULTS: Gold levels in plasma were significantly higher 0-12 months after gold inlay insertion than before treatment (p=0.008). No significant difference in gold plasma levels was found between 0-12 months after and 15 years after insertion (p=0.109), although there was a significant correlation between the number of gold alloy surfaces and the amount of gold in plasma 15 years after insertion (p=0.028). CONCLUSIONS: This study supports a dose-related release of gold into plasma from dental gold restorations, a release that appears to be stable over time.

  • 8.
    Ahlqvist, Jan B
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Nilsson, Tore A
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Hedman, Leif R
    Umeå universitet, Samhällsvetenskapliga fakulteten, Institutionen för psykologi.
    Desser, Terry S
    Dev, Parvati
    Johansson, Magnus
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Youngblood, Patricia L
    Cheng, Robert P
    Gold, Garry E
    A randomized controlled trial on 2 simulation-based training methods in radiology: effects on radiologic technology student skill in assessing image quality.2013Inngår i: Simulation in Healthcare: The Journal of the Society for Simulation in Healthcare, ISSN 1559-2332, E-ISSN 1559-713X, Vol. 8, nr 6, s. 382-387Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    INTRODUCTION: A simulator for virtual radiographic examinations was developed. In the virtual environment, the user can perform and analyze radiographic examinations of patient models without the use of ionizing radiation. We investigated if this simulation technique could improve education of radiology technology students. We compared student performance in the assessment of radiographic image quality after training with a conventional manikin or with the virtual radiography simulator.

    METHODS: A randomized controlled experimental study involving 31 first-year radiology technology students was performed. It was organized in 4 phases as follows: (I) randomization to control or experimental group based on the results of an anatomy examination; (II) proficiency testing before training; (III) intervention (control group, exposure and analysis of radiographic images of the cervical spine of a manikin; experimental group, exposure and analysis of the cervical spine images in the virtual radiography simulator); and (IV) proficiency testing after training.

    RESULTS: The experimental group showed significantly higher scores after training compared with those before training (P < 0.01). A linear mixed-effect analysis revealed a significant difference between the control and experimental groups regarding proficiency change (P = 0.01).

    CONCLUSIONS: Virtual radiographic simulation is an effective tool for learning image quality assessment. Simulation can therefore be a valuable adjunct to traditional educational methods and reduce exposure to x-rays and tutoring time.

  • 9.
    Ahlqvist, Jan, Birger
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Borg, Kennet
    Gunne, Johan
    Nilson, Hans
    Olsson, Morgan
    Åstrand, Per
    Osseointegrated implants in edentulous jaws: a 2-year longitudinal study.1990Inngår i: International Journal of Oral & Maxillofacial Implants, ISSN 0882-2786, E-ISSN 1942-4434, Vol. 5, nr 2, s. 155-163Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Osseointegrated implants in 50 edentulous jaws were studied during a 2-year observation period. The implant survival rate was 89% in the maxillae and 97% in the mandibles. The marginal bone loss averaged 1.7 mm in the maxillae and 1.1 mm in the mandibles. Most of this bone loss occurred during the first year. The bone loss was greater in jaws with a preoperatively minor resorption of the alveolar ridge than in those with moderate or advanced resorption. The bone loss was also greater at the medially positioned implants than at those more posterior.

  • 10. Ahlqvist, Jan
    et al.
    Eliasson, S
    Welander, U
    The effect of projection errors on cephalometric length measurements1986Inngår i: European Journal of Orthodontics, ISSN 0141-5387, E-ISSN 1460-2210, Vol. 8, nr 3, s. 141-148Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The magnitude of projection errors, calculated theoretically on length measurements in cephalometry was studied. Rotation of the object by up to 5° from the proper position, resulted in errors in length measurements that were usually less than one percent. Rotations of more than 5° may increase the error but imply misalignments of the head that should be evident when positioning the patient. The advantage of extremely long focus film distances seems doubtful.

  • 11. Ahlstrand, Tuuli
    et al.
    Kovesjoki, Laura
    Maula, Terhi
    Oscarsson, Jan
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Ihalin, Riikka
    Aggregatibacter actinomycetemcomitans LPS binds human interleukin-82019Inngår i: Journal of Oral Microbiology, E-ISSN 2000-2297, Vol. 11, nr 1Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Various gram-negative species sequester host cytokines using outer membrane proteins or surface modulation by sulfated polysaccharides. An outer membrane lipoprotein (BilRI) of the periodontal pathogen Aggregatibacter actinomycetemcomitans binds several cytokines, including interleukin (IL)-8. Because IL-8 is positively charged at physiological pH, we aimed to determine whether IL-8 interacts with negatively charged lipopolysaccharide (LPS). Binding was investigated using electrophoretic mobility shift assays and microwell-based time-resolved fluorometric immunoassay. LPS from each tested strain of A. actinomycetemcomitans (N = 13), Pseudomonas aeruginosa (N = 1) and Escherichia coli (N = 1) bound IL-8. The K-d value of the A. actinomycetemcomitans LPS-IL-8 interaction varied between 1.2-17 mu M irrespective of the serotype and the amount of phosphorus in LPS and was significantly lower than that of the BilRI-IL-8 interaction. Moreover, IL-8 interacted with whole A. actinomycetemcomitans cells and outer membrane vesicles. Hence, LPS might be involved in binding of IL-8 to the outer membrane of A. actinomycetemcomitans. This raises an interesting question regarding whether other gram-negative periodontal pathogens use LPS for IL-8 sequestering in vivo.

    Fulltekst (pdf)
    fulltext
  • 12.
    Aili, Margareta
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för molekylärbiologi (Teknisk-naturvetenskaplig fakultet).
    Role of YopE and LcrH in effector translocation, HeLa cell cytotoxicity and virulence2005Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    In order to establish an extra-cellular infection the gram-negative bacteria Yersinia pseudotuberculosis uses a type III secretion system (T3SS) to translocate a set of anti-host effectors into eukaryotic cells. The toxins disrupt signalling pathways important for phagocytosis, cytokine production and cell survival. Secretion and translocation via this T3SS is strictly regulated on several levels. In this context, the function of YopE and LcrH during Yersinia infections has been analysed.

    YopE is an essential translocated effector that disrupts the actin cytoskeleton of infected eukaryotic cells, by inactivating small GTPases through its GTPase activating protein (GAP) activity. However, cytotoxicity can be uncoupled from in vitro GAP activity towards the RhoA, Rac1 and Cdc42 GTPases. Furthermore, in vivo studies of the YopE GAP activity revealed that only RhoA and Rac1 are targeted, but this is not a pre-requisite for Yersinia virulence. Hence, YopE must target one or more additional GTPases to cause disease in mice.

    YopE was the only Yersinia effector that blocks LDH release from infected cells. Moreover, translocated YopE could regulate the level of subsequent effector translocation by a mechanism that involved the YopE GAP function and another T3S component, YopK. Loss of translocation control elevated total T3S gene expression in the presence of eukaryotic cells. This indicated the existence of a regulatory loop for feedback control of T3S gene expression in the bacteria that originates from the interior of the eukaryotic cell after effector translocation is completed. This might represent the true virulence function of YopE.

    Exoenzyme S (ExoS) of Pseudomonas aeruginosa has a YopE-like GAP domain with similar activity towards RhoA, Rac1 and Cdc42. However, ExoS is unable to complement hyper-translocation resulting from loss of YopE. This indicates a unique function for YopE in translocation control in Yersinia that might be dependent on correct intracellular localisation. It follows that the Membrane Localisation Domain in YopE was important for translocation control, but dispensable for cytotoxicity and blockage of LDH release.

    YopD and its cognate chaperone LcrH are negative regulatory elements of the T3S regulon and together with YopB, are involved in the effector translocation process. Randomly generated point mutants in LcrH specifically effected stability and secretion of both the YopB and YopD substrates in vitro and prevented their apparent insertion as translocon pores in the membranes of infected cells. Yet, these mutants still produced stable substrates in the presence of eukaryotic cells and most could mediate at least partial effector translocation. Thus, only minimal amounts of the YopB and YopD translocator proteins are needed for translocation and the LcrH chaperone may regulate this process from inside the bacteria.

    Fulltekst (pdf)
    FULLTEXT01
  • 13. Akkaoui, Sanae
    et al.
    Johansson, Anders
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Yagoubi, Maâmar
    Haubek, Dorte
    Aarhus University Denmark.
    El Hamidi, Adnane
    Mohammed V University in Rabat, Morocco.
    Rida, Sana
    Mohammed V University in Rabat, Morocco.
    Claesson, Rolf
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Ennibi, OumKeltoum
    Mohammed V University in Rabat, Morocco.
    Chemical Composition, Antimicrobial activity, in Vitro Cytotoxicity and Leukotoxin Neutralization of Essential Oil from Origanum vulgare against Aggregatibacter actinomycetemcomitans2020Inngår i: Pathogens, E-ISSN 2076-0817, Vol. 9, nr 3, artikkel-id 192Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this study, the essential oil of Origanum vulgare was evaluated for putative antibacterial activity against six clinical strains and five reference strains of Aggregatibacter actinomycetemcomitans, in comparison with some antimicrobials. The chemical composition of the essential oil was analyzed, using chromatography (CG) and gas chromatography-mass spectrometry coupled (CG-MS). The major compounds in the oil were Carvacrol (32.36%), α-terpineol (16.70%), p-cymene (16.24%), and Thymol (12.05%). The antimicrobial activity was determined by an agar well diffusion test. A broth microdilution method was used to study the minimal inhibitory concentration (MIC). The minimal bactericidal concentration (MBC) was also determined. The cytotoxicity of the essential oil (IC50) was <125 µg/mL for THP-1 cells, which was high in comparison with different MIC values for the A. actinomycetemcomitans strains. O. vulgare essential oil did not interfere with the neutralizing capacity of Psidium guajava against the A. actinomycetemcomitans leukotoxin. In addition, it was shown that the O. vulgare EO had an antibacterial effect against A. actinomycetemcomitans on a similar level as some tested antimicrobials. In view of these findings, we suggest that O.vulgare EO may be used as an adjuvant for prevention and treatment of periodontal diseases associated to A. actinomycetemcomitans. In addition, it can be used together with the previously tested leukotoxin neutralizing Psidium guajava.

    Fulltekst (pdf)
    fulltext
  • 14.
    Alatwan, Sham
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Tandläkarutbildning.
    Hermes, Sima
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Tandläkarutbildning.
    The Effect of Natural Therapeutic Agents on Virulence of Aggregatibacter actinomycetemcomitans2023Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    ABSTRACT 

    Background

    Adolescent carriers of Aggregatibacter actinomycetemcomitans JP2 genotype have an increased risk of developing periodontitis due to the high leukotoxin (LtxA) production of the bacterium. LtxA contributes to marginal bone loss by killing immunity cells, activating the proinflammatory interleukin-1β (IL-1β) which in turn activates the osteoclasts. A possible strategy to prevent periodontitis might be to neutralize LtxA in JP2-infected individuals. 

     

    Aim

    To investigate whether plant extracts from Matcha or Guava leaves can prolong the viability of macrophages in cell cultures by neutralizing the highly leukotoxic JP2 genotype bacteria.

     

    Material and methods

    A. actinomycetemcomitans JP2 genotype was pretreated with extracts from either Matcha or Guava leaves. Later, the extracts were rinsed before JP2 was exposed to macrophage cell cultures. The experiment was repeated, where JP2 was persistently treated with the extracts instead, i.e., extracts were not rinsed. The macrophage viability after bacterial exposure was analyzed and compared to untreated JP2 bacteria exposed to macrophages. IL-1β secretion in the cell culture medium was quantified in all group samples. 

     

    Results

    Pretreatment of A. actinomycetemcomitans JP2 genotype with Matcha or Guava leaf extracts moderately neutralized LtxA activity, which resulted in prolonged macrophage viability and decreased IL-1β secretion. These effects of prolonged macrophage viability were enhanced when extracts were persistently present during the exposure. 

     

    Conclusion

    The results indicate that Matcha and Guava leaf extracts have effects on the virulence of A. actinomycetemcomitans JP2 genotype that may be useful in future treatment strategies to prevent periodontitis in JP2 carriers.

  • 15.
    Al-Bayati, Asal
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Laskar, Taha
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Caries Development At Different Tooth Surfaces In Swedish Adolescents Undergoing Orthodontic Treatment2023Independent thesis Advanced level (degree of Master (Two Years)), 30 poäng / 45 hpOppgave
    Abstract [en]

    Introduction

    Dental caries is the most common chronic infectious disease and is associated with plaque, bacteria, diet and saliva. Previous caries experience predicts 1/3 of future caries development. However, there is a lack of knowledge regarding the natural history of caries development at different surfaces and their relative ability to predict caries progression.  

    Aim

    The aim of this study was to describe the caries experience and progression of caries at different tooth surfaces during 5 years in patients undergoing orthodontic multibracket treatment.

    Methods

    In the previously conducted 452-study, children were examined at 12 and 17 years of age. There were 66 patients with multibrackets at the follow-up who we analyzed. Degrees of caries, fillings and missing tooth were registered in an excel file according to the dental statuses (baseline and follow up).  Excel and SPSS were used to compare the files and create figures. 

    Results

    The most affected pair of surfaces at 12 years of age are 36/46 buccally, then occlusally and at 17 years of age 36/46 occlusally and then approximally. The progression of caries and fillings during five years mostly affects 37/47 occlusally and then 17/27 occlusally. A progression also occurred at buccal surfaces 13-23.

    Conclusion 

    The results show that occlusal and approximal surfaces at molars experience caries most frequently and the progression is highest for the second molars. There was also a progression of caries noted on 13-23 which could be associated with the multibrackets. This information may be important in future risk assessment models.

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  • 16.
    Albertsson, Katarina Wikén
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    van Dijken, Jan W V
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Awareness of toothbrushing and dentifrice habits in regularly dental care receiving adults2010Inngår i: Swedish Dental Journal, ISSN 0347-9994, Vol. 34, nr 2, s. 71-78Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The aim of this study was to investigate toothbrushing and dentifrice habits in a Swedish adult population with relatively high caries frequency, which received regularly dental care and to evaluate the awareness of their toothbrush technique. Sixty adult participants with high caries frequency, 29 woman and 31 men, answered a self-reporting questionnaire with 42 questions concerning their oral care, brushing technique and -habits.The responses were related to their clinical behaviour observed during a customary toothbrushing session. Fifty-three participants fulfilled both the questionnaire and the clinical observation. Half of these used toothpaste containing 1450-1500 ppm fluoride but only one of all participants was aware of the fluoride concentration used. The majority used a manual toothbrush and 95% brushed their teeth twice a day using 0.9 g toothpaste. A wide range of brushing methods and habits was observed. Sixty percent did not brush systematically. Spitting of toothpaste-saliva during brushing was performed by 60% and after brushing by 15%.The observed brushing times were significantly higher than the self reported. The observed brushing times were <1 min: 3.4%, 1-2 min: 36.7% and >2 min: 47.0%. There was a significant correlation between observed brushing time and caries activity. Rinsing with water after brushing was performed once (32%) or twice (44%) during the observations. Only 9% rinsed with toothpaste slurry after brushing. It can be concluded that the awareness of the individual toothbrushing, post-brushing behaviour and the use of fluoride toothpaste was non-optimal in the adult participants. Oral health promotion by optimalized use of fluoride toothpaste and improved post-brushing behaviour should be recommended.

  • 17. Alghadir, Ahmad
    et al.
    Aly, Farag
    Zafar, Hamayun
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Klinisk oral fysiologi.
    Effect of face veil on ventilatory function among Saudi adult females2012Inngår i: Pakistan journal of medical sciences print, ISSN 1682-024X, E-ISSN 1681-715X, Vol. 28, nr 1, s. 71-74Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Objective: The use of face veil called "niqab" by women to cover their faces at public places is a common practice in some Muslim communities. The long-term effect of niqab use on ventilatory function (VF) has not previously been reported. The aim of this cross-sectional study was to compare VF between niqab wearing and non-niqab wearing healthy Saudi females. Methodology: Thirty eight healthy adult Saudi females participated in this study. Nineteen subjects were regular niqab users and the other nineteen were either not using niqab at all or used it for less than one hour per day. Forced vital capacity (FVC), forced expiratory volume in one second (FEV1), FEV1/FVC (%), and maximal voluntary ventilation (MVV) were recorded using a digital spirometer. Results: Mean values of FVC, FEV1, FEV1/FVC (%) and MVV for niqab wearers were significantly lower than the corresponding values for non-niqab wearers. Significant negative correlation was found between the FVC and FEV1 values and the number of hours of the use of face veil per day. Conclusions: Long-term use of traditional niqab use can affect VF.

  • 18. Alghadir, Ahmad H.
    et al.
    Zafar, Hamayun
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi. Department of Rehabilitation Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
    Iqbal, Zaheen A.
    Can jaw position affect the fine motor activity of the hand during writing?2020Inngår i: Brain and Behavior, ISSN 2162-3279, E-ISSN 2162-3279, Vol. 10, nr 12, artikkel-id e01887Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Jaw and neck systems have been shown to be functionally related and changes in either system can modulate gross motor functions, such as posture control. It remains to be seen if any change in jaw position can affect fine motor skills. The objective of this study was to determine the effect of resting, open and clenched jaw positions on various handwriting parameters while standing on firm and unstable surfaces.

    Methods: Handwriting samples were collected from 36 healthy male participants (age, 15-35 years) using a digitizer tablet (WACOM Intuos 4) with noninking pen in the resting, open and clenched jaw positions while standing on firm and unstable surfaces. The measured handwriting parameters included duration, vertical size, horizontal size, absolute size, average absolute velocity, and absolute jerk. Recordings and analyses were performed using NeuroScript MovAlyzeR software.

    Results: All handwriting parameters varied among the resting, open, and clenched jaw positions on both the firm and unstable surfaces. However, based on statistical analyses, there were no significant differences in the handwriting parameters among three jaw positions on both surfaces (p > .05).

    Conclusion: This study revealed that all handwriting parameters varied among the resting, open, and clenched jaw positions on both the firm and unstable surfaces, showing that change in the jaw motor system may potentially affect the fine motor skills. However, on statistical analysis, there was no significant effect of 3 studied jaw positions on fine motor skills as seen on gross motor skills among healthy individuals.

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  • 19. Alghadir, Ahmad H.
    et al.
    Zafar, Hamayun
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Iqbal, Zaheen A.
    Effect of three different jaw positions on postural stability during standing2015Inngår i: Functional Neurology, ISSN 0393-5264, E-ISSN 1971-3274, Vol. 30, nr 1, s. 53-57Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Studies in the literature show that jaw and neck regions are linked anatomically, biomechanically and neurologically. Voluntary clenching has been shown to improve muscle strength and performance of various motor tasks. Information from the neck sensory-motor system is reported to be important for posture. Hence it is reasonable to believe that activation of the jaw sensory-motor system has the potential to modulate posture. In a sample of 116 healthy subjects, we compared center of gravity (COG) velocity during quiet standing on a foam surface during three test positions: i) resting jaw, ii) open jaw, and iii) clenching; these were tested in two conditions: with eyes open and with eyes closed. The COG velocity decreased significantly during clenching in comparison to both open and resting jaw positions (p<0.0001). This suggests that the jaw sensory-motor system can modulate postural mechanisms. We conclude that jaw clenching can enhance postural stability during standing on an unstable surface in both the presence and absence of visual input in healthy adults and suggest that this should be taken into consideration in treatment and rehabilitation planning for patients with postural instability.

  • 20. Alghadir, Ahmad H.
    et al.
    Zafar, Hamayun
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi. Department of Rehabilitation Sciences, College of Applied Medical Sciences, King Saud University, Riyadh.
    Iqbal, Zaheen A.
    Effect of tongue position on postural stability during quiet standing in healthy young males2015Inngår i: Somatosensory & motor research, ISSN 0899-0220, E-ISSN 1369-1651, Vol. 32, nr 3, s. 183-186Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background and aims: Role of the neck and jaw sensory motor system in control of body balance has been established. Tongue is an integral part of jaw sensory motor system and helps in execution of purposeful and precise motor tasks like eating, drinking and speaking. The purpose of this study was to evaluate the possible effects of tongue position on the postural control system. Materials and method: We compared the mean center of gravity (COG) velocity during quiet standing on an unstable surface with eyes closed during two test conditions: (i) with habitual jaw resting position and (ii) with instructed tongue positioned against the upper incisors. One hundred and sixteen normal healthy male subjects (average age 31.56 +/- 8.51 years and height 170.86 +/- 7.26 cm) participated in the study. Their COG velocity (deg/s) was measured using the NeuroCom (R) Balance Master version 8.5.0 (Clackamas, OR, USA). Results and conclusions: The results show that COG velocity decreased significantly while tongue was positioned against upper incisors in comparison to the habitual jaw resting position. Our findings suggest that the tongue positioning can modulate postural control mechanisms. Tongue positioning against the upper incisors can enhance the postural stability during upright standing on an unstable surface and in the absence of vision in healthy young adults. Our findings can be of value for evaluation and rehabilitation protocols for postural control dysfunction.

  • 21. Alghadir, Ahmad
    et al.
    Zafar, Hamayun
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi. King Saud Univ, Coll Appl Med Sci, Rehabil Res Chair, Riyadh, Saudi Arabia.
    Iqbal, Zaheen A.
    Al-Eisa, Einas
    Work-Related Low Back Pain Among Physical Therapists in Riyadh, Saudi Arabia2017Inngår i: Workplace Health & Safety, ISSN 2165-0799, Vol. 65, nr 8, s. 337-345Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Low back pain (LBP) is a common health problem. Professions like physical therapy (PT), involving frequent lifting, bending, or standing, are at risk for developing LBP. The objective of this study was to determine the prevalence of work-related LBP and factors associated with and consequences of work-related LBP among physical therapists in Riyadh, Saudi Arabia. A self-administered online questionnaire (i.e., demographic data, history of LBP before and after working as a physical therapist, work setting, and effect on daily activities) was sent to 600 members of the Saudi PT association. Data were analyzed using the Pearson chi-square test and Mann-Whitney U test. Eighty-eight percent of potential respondents completed the questionnaire. Of these, 89.65% of the therapists reported LBP after beginning their PT practice, and 35.6% reported LBP at the time of this survey. Gender, PT specialty, and duration of contact with patients were all found to be related to LBP. The prevalence of work-related LBP among physical therapist in Riyadh was high, affecting patient care and daily activities of the therapists. Both primary and secondary prevention strategies (e.g., introduce ergonomics into PT curricula, reduce therapist stress, and promote teamwork) are needed to decrease LBP among therapists, so they can effectively care for patients.

  • 22. Alghadir, Ahmad
    et al.
    Zafar, Hamayun
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi. Department of Rehabilitation Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Saudi Arabia.
    Whitney, S. L.
    Iqbal, Zaheen
    Effect of chewing on postural stability during quiet standing in healthy young males2015Inngår i: Somatosensory & motor research, ISSN 0899-0220, E-ISSN 1369-1651, Vol. 32, nr 2, s. 72-76Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background and aims: There is an important role of the neck sensory motor system in control of body posture and balance, and it is reasonable to believe that the jaw sensory motor system can directly and indirectly influence the modulation of the postural control system. The purpose of this study was to evaluate possible effects of dynamic jaw position while chewing on the postural control system. Materials and methods: We compared the mean center of gravity (COG) velocity during quite standing on a foam surface with eyes closed during three test conditions: (i) with resting jaw position, (ii) with open jaw position, and (iii) while chewing standard bolus of chewing gum. One hundred and sixteen normal healthy male subjects (average age 31.56 +/- 8.51 years; height 170.86 +/- 7.26 cm) were recruited for the study. Their COG velocity (deg/s) was measured using the NeuroCom (R) Balance Master Version 8.5.0 (Clackamas, OR, USA). Statistical analysis: Data was tested by the Friedman test. Results and conclusions. The results show that COG velocity decreased significantly while chewing in comparison to both open and resting jaw position (p < 0.0001). Our finding corroborates previous studies and suggests that the jaw sensory motor system can modulate postural control mechanisms. Gum chewing activity can enhance the postural stability during upright standing on an unstable surface and in the absence of visual input in healthy young adults. Our results should be taken into consideration in treatment and rehabilitation planning for patients with postural instability.

  • 23.
    Alharbi, Adel F.
    et al.
    Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom; Medina Regional Laboratory, General Directorate of Health Affairs, Ministry of Health, Medina, Saudi Arabia.
    Sheng, Nongfei
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Nicol, Katie
    Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom.
    Strömberg, Nicklas
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Hollox, Edward J.
    Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom.
    Balancing selection at the human salivary agglutinin gene (DMBT1) driven by host-microbe interactions2022Inngår i: iScience, E-ISSN 2589-0042 , Vol. 25, nr 5, artikkel-id 104189Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Discovering loci under balancing selection in humans can identify loci with alleles that affect response to the environment and disease. Genome variation data have identified the 5′ region of the DMBT1 gene as undergoing balancing selection in humans. DMBT1 encodes the pattern-recognition glycoprotein DMBT1, also known as SALSA, gp340, or salivary agglutinin. DMBT1 binds to a variety of pathogens through a tandemly arranged scavenger receptor cysteine-rich (SRCR) domain, with the number of domains polymorphic in humans. We show that the signal of balancing selection is driven by one haplotype usually carrying a shorter SRCR repeat and another usually carrying a longer SRCR repeat. DMBT1 encoded by a shorter SRCR repeat allele does not bind a cariogenic and invasive Streptococcus mutans strain, in contrast to the long SRCR allele that shows binding. Our results suggest that balancing selection at DMBT1 is due to host-microbe interactions of encoded SRCR tandem repeat alleles.

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  • 24.
    Al-Jubouri, Doaa
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Tandläkarutbildning.
    Saad, Mohammad
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Tandläkarutbildning.
    Three-Dimensionally Printed Versus Conventionally Cured Polymer-Based Material For Interim Restorations.2021Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    ABSTRACT 

    Background: Three-dimensional (3D) printing is a manufacturing technique, based on building objects layer by layer. It has received more attention lately especially in the medical and dental fields.  

    Aim: To investigate two mechanical properties of three-dimensionally printed polymer-based materials and compare them with conventionally cured polymer-based material. 

    Methods: Samples of four 3D-printed polymer-based materials (NextDent C&B MFH; NextDent Denture 3D+; NextDent Ortho Rigid and Freeprint® temp) and a conventionally cured and hand-mixed polymer-based provisional material (Luxatemp star) were investigated. Flexural strength and Vickers hardness were analyzed. Before the tests were carried out, all samples were placed in water in 37°C for at least 24 hours.  

    Results: The flexural strength results showed that there was statistically significant difference between Luxatemp star, NextDent C&B MFH and Freeprint®temp. Both 3D printed materials had a higher flexural strength than the conventionally cured material (Luxatemp star). At the same time, there was no statistically significant difference between Luxatemp star, NextDent Denture 3D+ and NextDent Ortho Rigid. The hardness values showed no statistically significant difference between the conventionally cured material (Luxatemp star) and the 3D printed materials. Furthermore, no statistically significant differences could be seen between the different 3D printed materials. 

    Conclusions: NextDent C&B MFH and Freeprint®temp had higher flexural strength than the conventionally cured material. NextDent Ortho Rigid and NextDent Denture 3D+ had a flexural strength comparable to the conventionally cured polymer-based material. 3D printed materials had a hardness comparable to the conventionally cured ones.

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  • 25.
    Al-Karawi, Zainab
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Gholami, Arzo
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Healthcare Utilization related to Symptoms from Jaw, Head and Neck-Shoulder regions among Sami Women2022Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
  • 26.
    Alkhaiat, Reem
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Jaber, Zahra
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Maximal voluntary occlusal bite force in young adult men -a pilot study2020Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Background: Maximal voluntary occlusal bite force (MVOBF) is the maximal force applied by the jaw muscles in dental occlusion. MVOBF is one parameter for functional capacity of the jaw system. 

    Aim: To evaluate MVOBF in different positions in the bite and to evaluate possible intra-individual differences between sessions. 

    Methods: MVOBF was measured with an electronic bite force device, with transducers sensitive to force, in 20 healthy men (mean 24.5 years). Eligibility of participants was full dental occlusion, Angle Class I relation, no diagnosis according to Diagnostic criteria for temporomandibular disorders. The test included three repeated measurements on each site: first molar right, first molar left and central incisor, in random order, with test-retest study design. Unpaired T-test was used to test the MVOBF in different positions in the bite and paired T-test for possible intra-individual differences between sessions. A post hoc test for repeated measure one-way ANOVA was added. 

    Results: MVOBF in different positions in the bite was lower in the incisor area compared with the molar region (P<0.0001), but similar between right and left molar side (P=0.48 and P= 0.96, respectively). No intra-individual differences between sessions (molar right P= 0.40; molar left P= 0.81; incisor area P= 0.66). The intra-individual variability for repeated measurements showed variability for incisor area (P= 0.007), but not for molar right and left region (P=0.95 and P=0.49, respectively). 

    Conclusion: The results may provide reference values for MVOBF in young adult men, to be compared with men with pain or dysfunction in the jaw system.

     

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  • 27.
    Al-lami, Reem
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Tandläkarutbildning.
    Azin, Roxana
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Tandläkarutbildning.
    Proportion and Quantity of Aggregatibacter aphrophilus in Plaque from Adolescents with and without Alveolar bone loss in Västerbotten County2021Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Background: Periodontitis is a inflammatory disease defined by alveolar bone loss (ABL). A common pathogen involved is Aggregatibacter actinomycetemcomitans and it is closely related to Aggregatibacter aphrophilus that is found in the oral microbiome and has low virulence in periodontitis. It is hypothesized that presence of high levels of A. aphrophilus may be beneficial for periodontal health by taking up space, thereby preventing A. actinomycetemcomitans from growing in high numbers. 

    Aim: The aim is to study a possible relationship between A. aphrophilus and A. actinomycetemcomitans and evaluate whether the presence of high levels of A. aphrophilus in plaque might be accompanied by low levels of A. actinomycetemcomitans in the same niche. 

    Methods: X-rays from 1655 youths born 2001, were analyzed in an ongoing PhD project. 24 individuals with ABL were found and 13 of them participated in the study. A control group was randomly selected. In the present project, the levels of the two Aggregatibacter species in plaque samples, previously collected from 37 of the volunteers were measured earlier with qPCR. 

    Results: The levels of A. aphrophilus compared to A. actinomycetemcomitans in the group with ABL varied between the samples and did not show a statistically significant difference. For the control group, A. aphrophilus were present in 81% compared to 20% presence of A. actinomycetemcomitans. The results showed statistical significance for the control group. 

    Conclusions: Our findings suggests that high levels of A. aphrophilus can be associated with periodontal health. Also, our results indicate a possible inverse relationship between the two bacteria. 

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    Abstract
  • 28.
    Almosa, Naif A.
    et al.
    Department of Pediatric Dentistry and Orthodontics, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
    Zafar, Hamayun
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi. Department of Rehabilitation Sciences, College of Applied Medical Sciences and, Rehabilitation Research Chair, King Saud University, Riyadh, Saudi Arabia.
    Assessment of knowledge about dental ergonomics among dental students of King Saud University, Riyadh, Kingdom of Saudi Arabia2019Inngår i: Journal of Contemporary Dental Practice, E-ISSN 1526-3711, Vol. 20, nr 3, s. 324-329Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aim: To assess the knowledge about dental ergonomics and work-related musculoskeletal disorders (WRMSDs) among dental students of King Saud University (KSU), Riyadh, Kingdom of Saudi Arabia, undergoing practical clinical training.

    Materials and methods: A self-designed questionnaire after pre-testing was distributed to 150 dental students of KSU undergoing clinical training, to collect data related to (a) basic knowledge about dental ergonomics; (b) any course/workshop about dental ergonomics attended; (c) basic knowledge about WRMSDs; (d) familiarity about preventive measures to decrease the risk of WRMSDs; and (e) knowledge about treatment options for WRMSDs.

    Results: One hundred forty-two students (95%) returned the completed questionnaires, of them 54 (38%) were males and 88 (62%) were females. The main findings of the study are that only 30% of the students knew about dental ergonomics; 93% of students have not attended any course/workshop about dental ergonomics; about half the students knew about WRMSDs; 62% of the students did not know about preventive measures to decrease the risk of WRMSDs, and 80% of students did not have knowledge about treatment options for WRMSDs. In general, female students had a better understanding of dental ergonomics and WRMSDs than male students.

    Conclusion: The basic knowledge of the dental ergonomics among dental students at King Saud University, Riyadh, Kingdom of Saudi Arabia is not adequate.

    Clinical significance: There is a need for introducing dedicated theoretical and practical courses covering all aspects of dental ergonomics in the undergraduate curriculum of dental education.

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  • 29. Almosa, Naif
    et al.
    Zafar, Hamayun
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Incidence of orthodontic brackets detachment during orthodontic treatment: A systematic review2018Inngår i: Pakistan journal of medical sciences print, ISSN 1682-024X, E-ISSN 1681-715X, Vol. 34, nr 3, s. 744-750Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Objectives: To evaluate the incidence of orthodontic brackets detachment during orthodontic treatment.

    Methods: Using electronic databases; eligible studies up to January 2018 were retrieved, independently reviewed, and screened. The Coleman Methodology Scoring System (CMS) and Cochrane Collaboration's tool were used to assess quality and risk of bias in the included studies.

    Results: Of the seventeen studies included in the final synthesis, thirteen were categorized as randomized clinical trials (RCTs), one prospective cohort and retrospective survey each, whereas two studies could not be categorized. The number of patients in the selected studies ranged between 19 and 153; the mean age was between 10.5 to 38.7 years, and male to female ratio was 353:495. Almost all studies had a high risk of bias, and more than half of the studies had CMS score of 70 or above. The numbers of brackets examined in the studies ranged between 361 and 3336. The incidence of brackets detachment ranged from 0.6 to 28.3%.

    Conclusions: The incidence of brackets detachment during orthodontic treatment is high.

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  • 30.
    Al-Nazary, Ashuriina
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Khajeh Amid, Nejlika
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Lactobacilli, probiotic and cariogenic species? - A litterature study2023Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
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  • 31.
    Al-Taai, Nameer
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Dentoalveolar and craniofacial changes from early adolescence to late adulthood2022Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Objectives: Study I: To evaluate the reliability and validity of different superimposition methods and to increase the precision with which craniofacial growth and treatment can be quantified. Study II: To explore the craniofacial changes that occur from early adolescence to late adulthood. Study III: To assess the impact of premolar extractions on dentoskeletal and facial morphologies up to late adulthood. Study IV: In a 50-year follow-up, to study how early extraction of four premolars affects the development of age-related lower incisor crowding. 

    Materials and Methods: Study I: Forty pairs of cephalograms were analysed at mean ages of 9.9 (T1) and 15.0 (T2) years. Three superimposition methods were assessed: the Sella-Nasion (SN); the Tuberculum Sella-Wing (TW); and Björk’s structural. Björk’s structural method was performed using three techniques: direct, tracing template, and subtraction. Study II: Thirty subjects with a Class I normal occlusion and harmonious facial profile were investigated. Study data were obtained from cephalograms performed at 12 (T1), 15 (T2), 30 (T3), and 62 (T4) years of age. The craniofacial changes were assessed using superimposition-based and conventional cephalometric methods. Study III: Two groups were included. The Extraction group (N=30 with Class I crowding malocclusion) had their first premolars extracted at a mean age of 11.5 years, without subsequent orthodontic treatment. The Control group included 30 untreated subjects with Class I normal occlusion. Study data were obtained from cephalograms performed at 12 (T1), 15 (T2), 30 (T3) and 62 (T4) years of age. The dentoskeletal and soft tissue changes were assessed using superimposition-based and conventional cephalometric methods. Study IV: Two groups were included. The Extraction group (N=24 with Class I crowding malocclusion) that had their first premolars extracted at mean age of 11.5 years, without subsequent orthodontic treatment. The Control group included 21 untreated subjects with Class I normal occlusion. Study data were obtained from dental casts and cephalograms performed at mean ages of 11.4 and 13.0 years, for the two groups, respectively (T1), and at mean ages of 30.9 years (T2) and 61.7 years (T3).

    Results: Study I: The numerical data from the superimposition-based cephalometrics reflected a graphical illustration of superimposition and differed significantly from the data acquired using conventional cephalometrics. While there were no significant differences between the TW method and Björk’s three techniques, significant differences were found between the SN method and the other methods. Study II: The maxilla and mandible showed significant anterior growth from T1 to T2, and significant retrognathism from T3 to T4. The anterior facial height and jaw dimensions increased significantly until T3. From T3 to T4, significant posterior rotation of the mandible and opening of the vertical jaw relation were observed, in addition to significant retroclination of the upper incisors, decrease in lip prominence, and straightening of the facial profile. Study III: There were no significant differences between the Extraction and Control groups in terms of the skeletal sagittal relation, incisor inclination and protrusion (or for most of the soft tissue parameters) during the observation period. Study IV: The Extraction group showed significant improvement in the space deficiency of the lower teeth and no changes in the irregularity of the lower incisors up to late adulthood. In contrast, both the space deficiency of the lower teeth and irregularity of the lower incisors were significantly exacerbated in the Control group, up to late adulthood. 

    Conclusions: The superimposition-based cephalometric method accurately generates numerical data for the craniofacial changes. Superimposition using the TW method is valid, reliable, and feasible, and is recommended to be used for superimposition-based cephalometrics. Moreover, craniofacial changes and development of lower incisor irregularity and crowding continue up to late adulthood in untreated subjects who were originally classified as having normal occlusion. For successful long-term outcomes, clinicians should therefore consider age-related changes in patients when planning for orthodontic, orthognathic, and prosthodontic treatments. Treatment with the extraction of four premolars alone in patients with Class I malocclusion with severe crowding does not impact the long-term dentoskeletal and soft tissue profile, and results in unchanged lower incisor alignment.

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  • 32.
    Al-Taai, Nameer
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Alfatlawi, Fakhri
    Department of Orthodontics, College of Dentistry, University of Baghdad, Baghdad, Iraq.
    Ransjö, Maria
    Department of Orthodontics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Fakhry, Saad
    Department of Endocrinology and Metabolism, College of Medicine, University of Al-Nahrain, Baghdad, Iraq.
    Effect of rapid maxillary expansion on monosymptomatic primary nocturnal enuresis2015Inngår i: Angle orthodontist, ISSN 0003-3219, E-ISSN 1945-7103, Vol. 85, nr 1, s. 102-108Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Objective: To evaluate the effects of rapid maxillary expansion (RME) on nocturnal enuresis (NE) related to the nasal airway, nasal breathing, and plasma osmolality (as an indicator for antidiuretic hormone).

    Materials and Methods: Nineteen patients with monosymptomatic primary NE, aged 6-15 years, were treated with RME for 10-15 days. To exclude a placebo effect of the RME appliance, seven patients were first treated with a passive appliance. Computed tomography of nasal cavity, rhinomanometric, and plasma osmolality measurements were made 2-3 days before and 2-3 months after the RME period. RME effects on NE were followed for three more years.

    Results: Two to three months after the expansion there were significant improvements in the breathing function and a decrease in the plasma osmolality. NE decreased significantly in all patients after the RME period, and all patients showed full dryness after 3 years.

    Conclusions: This study demonstrates that RME causes complete dryness in all patients, with significant effects on pathophysiological mechanisms related to NE.

  • 33.
    Al-Taai, Nameer
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Levring Jäghagen, Eva
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Persson, Maurits
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Ransjö, Maria
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi. Department of Orthodontics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Westerlund, Anna
    Department of Orthodontics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    A superimposition-based cephalometric method to quantitate craniofacial changes2021Inngår i: International Journal of Environmental Research and Public Health, ISSN 1661-7827, E-ISSN 1660-4601, Vol. 18, nr 10, artikkel-id 5260Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    To assess the craniofacial changes related to growth and/or to orthodontic and orthognathic treatments, it is necessary to superimpose serial radiographs on stable structures. However, conventional superimposition provides only a graphical illustration of these changes. To increase the precision of growth and treatment evaluations, it is desirable to quantitate these craniofacial changes. The aims of this study were to (1) evaluate a superimposition-based cephalometric method to process numerical data for craniofacial growth changes and (2) identify a valid, reliable, and feasible method for superimposition. Forty pairs of cephalograms were analyzed at T1 and T2 (mean age 9.9 and 15.0 years, respectively). The superimposition-based cephalometric method involved relating the sagittal and vertical measurements on the T2 radiographs to the nasion and sella landmarks on the T1 radiographs. Validity and reliability were evaluated for three superimposition methods: the sella-nasion (SN); the tuberculum sella-wing (TW); and Björk’s structural. Superimposition-based cephalometrics can be used to quantify craniofacial changes digitally. The numerical data from the superimposition-based cephalometrics reflected a graphical illustration of superimposition and differed significantly from the data acquired through conventional cephalometrics. Superimposition using the TW method is recommended as it is valid, reliable, and feasible.

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  • 34.
    Al-Taai, Nameer
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi. Orthodontics, Department of Odontology, Umeå University, Umeå, Sweden.
    Persson, Maurits
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi. Orthodontics, Department of Odontology, Umeå University, Umeå, Sweden.
    Ransjö, Maria
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi. Orthodontics, Department of Odontology, Umeå University, Umeå, Sweden;Department of Orthodontics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Levring Jäghagen, Eva
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi. Oral and Maxillofacial Radiology, Department of Odontology, Umeå University, Umeå, Sweden.
    Fors, Ronny
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi. Orthodontics, Department of Odontology, Umeå University, Umeå, Sweden.
    Westerlund, Anna
    Department of Orthodontics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Craniofacial changes from 13 to 62 years of age2022Inngår i: European Journal of Orthodontics, ISSN 0141-5387, E-ISSN 1460-2210, Vol. 44, nr 5, s. 556-565Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: In long-term studies of orthodontic, orthognathic, and prosthodontic treatments, control subjects are needed for comparison.

    Objectives: To study the craniofacial (skeletal, soft tissue, and dental) changes that occur in untreated subjects with normal occlusion between13 and 62 years of age.

    Materials/Methods: Thirty subjects with a Class I normal occlusion and harmonious facial profle were studied. X-ray examinations were performed at 13 (T1), 16 (T2), 31 (T3), and 62 (T4) years of age, and data were obtained from cephalograms. In total, 53 angular and linear parameters were measured using superimposition-based and conventional cephalometric methods to describe the craniofacial changes.

    Results: The jaws showed signifcant anterior growth from T1 to T2, and signifcant retrognathism from T3 to T4. The anterior face height andjaw dimensions increased signifcantly until T3. Signifcant posterior rotation of the mandible and opening of the vertical jaw relation, in additionto signifcant retroclination of the incisors and straightening of the facial profle, were found from T3 to T4.Limitations: Given the small sample size at T4, it was not possible to analyse the gender dimension.

    Conclusions/Implications: Craniofacial changes continue up to the sixth decade of life. These changes are consistent, albeit to a lesser extent,with the adolescent growth patterns for most of the studied parameters, with the exceptions of incisor inclination, sagittal jaw position, verticaljaw relation and inclination, and posterior face height.

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  • 35.
    Al-Taai, Nameer
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Persson, Maurits
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Ransjö, Maria
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi. Department of Orthodontics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Levring Jäghagen, Eva
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Westerlund, Anna
    Department of Orthodontics, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
    Dentoskeletal and soft tissue changes after treatment of crowding with premolar extractions: a 50-year follow-up2023Inngår i: European Journal of Orthodontics, ISSN 0141-5387, E-ISSN 1460-2210, Vol. 41, nr 1, s. 79-87Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: The long-term effects on dentofacial morphology of interceptive treatment with premolar extractions, in the absence of subsequent orthodontic treatment, have not been fully explored.

    Objective: The aim was to investigate the effects of premolar extractions (without subsequent orthodontic treatment) on the dentoskeletal and soft tissue profile of patients aged between 12 and 62 years with Class I malocclusion with severe crowding, as compared to untreated controls.

    Materials and methods: The Extraction group (N = 30 with Class I crowding malocclusion) had their first premolars removed in early adolescence without subsequent orthodontic treatment. The Control group included 30 untreated subjects with Class I normal occlusion. Cephalograms were taken at 12 (T1), 15 (T2), 30 (T3), and 62 (T4) years of age. A superimposition-based cephalometric method was used to assess the dentoskeletal and soft tissue changes.

    Results: There were no significant differences between the Extraction and Control groups in terms of skeletal sagittal relation, incisor inclination, and protrusion, or most of the soft tissue parameters throughout the observation period. However, significant differences were observed between the groups with respect to the vertical relations in T2-T3, such that the Extraction group showed more-pronounced decreases in the ML/NSL, ML/NL, and Gonial angles and more-pronounced increases in facial heights.

    Conclusions and implications: Treatment for subjects with Class I malocclusion with severe crowding by the extraction of four premolars, without subsequent orthodontic treatment, does not affect the long-term dentoskeletal and soft tissue profile, as compared to an untreated Control group. The degree of crowding, rather than changes in dentofacial morphology, is crucial in deciding on extraction therapy.

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  • 36. Andersson, A
    et al.
    Sköld-Larsson, K
    Hallgren, A
    Pettersson, LG
    Twetman, Svante
    Umeå universitet, Medicinsk fakultet, Odontologi.
    White spot lesion regression with the CPP-ACP system assessed by a laser fluorescence device (DIAGNOdent).2006Inngår i: Oral Health Prev DentArtikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose: To investigate and compare the effects of a dental cream containing complexes of casein phosphoprotein-amorphous calcium phosphate (CPP-ACP) and fluoride mouth rinses on the regression of white spot lesions (WSL). Material and methods: The study group consisted of 26 healthy adolescents (mean age 14.6 yr) exhibiting 60 teeth with 152 visible WSL sites on incisors and canines immediately after debonding of fixed orthodontic appliances. After bracket removal, professional tooth cleaning and drying, a visual scoring (0-4) and laser fluorescence (LF) readings were carried out. The patients were randomly assigned to two different treatment protocols with the aim to remineralize the lesions: A) daily topical applications of a dental cream containing CPP-ACP (Topacal) for 3 months followed by a 3-month period of daily tooth brushing with fluoridated toothpaste, or B) daily 0.05% sodium fluoride rinses combined with fluoridated toothpaste for 6 months. The registrations were repeated after 1, 3, 6 and 12 months and follow-up data were compared with baseline with aid of chi-square and paired t-tests. Results: A significant improvement of the clinical WSL-scores was found over time in both groups but there was a statistically significant difference (p<0.01) concerning the number of sites that totally disappeared after 12 months in favor for the CPP-ACP regime, 63% vs. 25% respectively. The clinical registrations were mirrored by a statistically significant decrease (p<0.05) in the LF readings at the 6- and 12-month follow-ups compared to baseline. No significant differences were displayed between the groups. Conclusion: Clinical scoring and LF assessment suggested that both regimens could promote regression of WSL after debonding of fixed orthodontic appliances. The visual evaluation suggested an aesthetically more favourable outcome of the amorphous calcium phosphate treatments.

  • 37.
    André, Maria
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Kou, Wen
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Sjögren, Göran
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Sundh, Anders
    Research and Development, Cad.esthetics AB, Skellefteå, Sweden.
    Effects of pretreatments and hydrothermal aging on biaxial flexural strength of lithium di-silicate and Mg-PSZ ceramics2016Inngår i: Journal of Dentistry, ISSN 0300-5712, E-ISSN 1879-176X, Vol. 55, s. 25-32Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Objectives: To evaluate the effect of specimen thickness, pretreatment and hydrothermal aging on the biaxial flexural strength (BFS) of lithium di-silicate glass (e.max Cad) and magnesia-stabilized zirconia (ZirMagnum) ceramic discs. Methods: The e.max Cad discs was studied: i) crystallized, ii) crystallized and glazed and iii) crystallized, glazed and unglazed side etched with hydrofluoric acid. The ZirMagnum discs were studied: i) as delivered, ii) after sandblasting and iii) after heat treatment similar to veneering. Hydrothermal aging was simulated by autoclave treatment. Results: The BFS of all the ZirMagnum specimens was superior (p < 0.001) to all the e.max Cad specimens. Glazing the 0.4 mm e.max Cad discs reduced (p < 0.05) their BFS compared with the unglazed 0.8 mm specimens, whereas glazing of 0.8 mm discs had no influence (p > 0.05) on the strength. Etching and autoclaving of e.max Cad did not affect (p > 0.05) the BFS. For ZirMagnum sandblasting with 0.2 MPa or 0.6 MPa did not influence the biaxial flexural strength (p > 0.05), whereas heat treatment reduced (p < 0.01) the BFS of 0.6 MPa sandblasted ZirMagnum. Autoclaving reduced the strength (p < 0.05) compared with ZirMagnum as delivered, whereas autoclaving of the 0.6 MPa sandblasted and heat treated specimens did not influence (p > 0.05) the BFS. Glazing, etching and sandblasting increased (p < 0.05) surface roughness. Conclusions: The effects of glazing, heat treatment, aging and mechanical treatment of the materials evaluated should be considered since their strength could be affected. Clinical significance: Mechanical properties of restorations made from prefabricated ceramic blocks could be affected of various treatments and could change over time.

  • 38.
    Andréason, Fanny
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Almelund, Lisa
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Potential Effects On Oral Health And Otitis In 3-Year Old Children Consuming Probiotic Lactobacilli2021Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Background: Probiotic products are used to improve health, cure disease and in a prophylactic aim. However, there is limited research about its general effects on health in children, especially on oral health. 

    Aim: This study aimed to evaluate potential effects on oral health and otitis in 3-year- old children consuming probiotic Lactobacillus reuteri 17938 and Lactobacillus reuteri 5289. 

    Methods: This was a quantitative cross-sectional study where questionnaires concerning health and lifestyle of children (n=169) participating in the longitudinal study NorthPop Child, at the age of 4, 9, 18 and 36 months old, were compared to clinical parameters from a visit at the Public Dental Health Care at 3 years of age. Saliva samples from 142 children were analyzed by PCR. Results: This study showed that children consuming Lactobacillus reuteri 17938, had prevalence of the bacteria in saliva. Prevalence of Lactobacillus reuteri 5289 in saliva was not indicated. The prevalence of caries disease tended to be lower in probiotic- consuming children, though not statistically significant. Children consuming probiotics showed a higher prevalence of otitis and consumption of antibiotics compared to non- eaters. 

    Conclusion: Any conclusions about consumption and frequency required to gain and maintain the bacteria in the oral microbiome could not be made. Contradictory to other studies, this study found that children who consumed probiotics had more occasions of otitis media and antibiotic use. Future studies with a higher number of participants would be of interest to confirm these potential findings. 

  • 39.
    Anticona, Cynthia
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Hansson, Lena
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Pediatrik.
    Johansson, Ingegerd
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Lif Holgerson, Pernilla
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Exploring the possible impact of oral nutritional supplements on children's oral health: an in vitro investigation2024Inngår i: Dentistry Journal, E-ISSN 2304-6767, Vol. 12, nr 3, artikkel-id 78Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Eight pediatric oral nutritional supplements (ONSs) and 0.5% fat bovine milk were examined in vitro regarding their effect on the adhesion of three caries-related bacteria, Streptococcus mutans (strain CCUG 11877T), Lactobacillus gasseri (strain CCUG 31451), and Scardovia wiggsiae (strain CCUG 58090), to saliva-coated hydroxyapatite, as well as their pH and capacity to withstand pH changes. Bacteria were cultivated and radiolabeled. The adhesion assays used synthetic hydroxyapatite coated with whole or parotid saliva. Measurements of pH and titration of the products with HCl and NaOH were conducted in triplicate. Three ONSs promoted the S. mutans adhesion to saliva-coated hydroxyapatite (increase from 35% to >200%), supporting caries risk enhancement. S. wigssiae and L. gasseri adhered only to one and no ONS, respectively. Most supplements had limited buffering capacity to counteract acidification changes, suggesting their low capacity to neutralize acids, and one ONS showed a significant capacity to counteract basic changes, suggesting a high erosive potential. S. mutans adhesion was influenced by the ONS pH and volume NaOH added to reach pH 10. L. gasseri and S. wiggsiae adhesion was influenced by the ONSs' carbohydrate and fat content. Interdisciplinary efforts are needed to increase awareness and prevent the possible negative impact of ONSs on children's oral health.

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  • 40.
    Anticona, Cynthia
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Hansson, Lena
    Umeå universitet, Medicinska fakulteten, Institutionen för klinisk vetenskap, Pediatrik.
    Johansson, Ingegerd
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Kariologi.
    Lif Holgerson, Pernilla
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Exploring the possible impact of oral nutritional supplements on children’s oral health: an in vitro investigation2024Inngår i: Dentistry Journal, E-ISSN 2304-6767, Vol. 12, nr 3, artikkel-id 78Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Eight pediatric oral nutritional supplements (ONSs) and 0.5% fat bovine milk were examined in vitro regarding their effect on the adhesion of three caries-related bacteria, Streptococcus mutans (strain CCUG 11877T), Lactobacillus gasseri (strain CCUG 31451), and Scardovia wiggsiae (strain CCUG 58090), to saliva-coated hydroxyapatite, as well as their pH and capacity to withstand pH changes. Bacteria were cultivated and radiolabeled. The adhesion assays used synthetic hydroxyapatite coated with whole or parotid saliva. Measurements of pH and titration of the products with HCl and NaOH were conducted in triplicate. Three ONSs promoted the S. mutans adhesion to saliva-coated hydroxyapatite (increase from 35% to >200%), supporting caries risk enhancement. S. wigssiae and L. gasseri adhered only to one and no ONS, respectively. Most supplements had limited buffering capacity to counteract acidification changes, suggesting their low capacity to neutralize acids, and one ONS showed a significant capacity to counteract basic changes, suggesting a high erosive potential. S. mutans adhesion was influenced by the ONS pH and volume NaOH added to reach pH 10. L. gasseri and S. wiggsiae adhesion was influenced by the ONSs’ carbohydrate and fat content. Interdisciplinary efforts are needed to increase awareness and prevent the possible negative impact of ONSs on children’s oral health.

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    fulltext
  • 41.
    Anticona Huaynate, Cynthia
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Lif Holgerson, Pernilla
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Gustafsson, Per E
    Umeå universitet, Medicinska fakulteten, Institutionen för epidemiologi och global hälsa.
    Assessing inequities in unmet oral care needs among adults in Sweden: An intersectional approach2023Inngår i: Community Dentistry and Oral Epidemiology, ISSN 0301-5661, E-ISSN 1600-0528, Vol. 51, nr 3, s. 428-435Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Objectives: The goal of the Swedish oral healthcare system is to achieve good oral health and equitable access to care for the entire population. However, considerable inequities in oral health and care are evident and occur across a range of social dimensions. This study uses an intersectional approach to examine complex inequities in unmet oral care needs among adults in Sweden over the period 2004–2021.

    Methods: Data were obtained from 14 Health on Equal Terms surveys conducted during 2004–2021. The final sample was 129 473 individuals aged 26–84 years. Applying intersectional analysis of individual heterogeneity and discriminatory accuracy, inequities in unmet oral care needs were estimated across 48 intersectional strata defined by gender, age, educational level, individual disposable income and immigrant status.

    Results: A high risk of unmet oral care needs was found among strata consisting of immigrants and those with low income. However, being an immigrant and/or having a low income did not universally entail a high risk but varied by the social position along other axes, particularly age and education. The discriminatory accuracy was moderate.

    Conclusion: Groups with certain social disadvantages are highly heterogeneous themselves. An intersectionality approach is important to prevent the risk of stigmatizing large heterogenous groups while failing to identify the most vulnerable strata. The discriminatory accuracy analysis suggested that further policy and/or interventions may be the most effective if approaching the whole population, combined with selected targeted interventions directed at the most disadvantaged social strata.

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  • 42.
    Anticona Huaynate, Cynthia
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för epidemiologi och global hälsa. Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Suominen, Anna Liisa
    Institute of Dentistry, University of Eastern Finland, Kuopio, Finland; Oral and Maxillofacial Teaching Unit, Kuopio University Hospital, Kuopio, Finland.
    Lif Holgerson, Pernilla
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Gustafsson, Per E.
    Umeå universitet, Medicinska fakulteten, Institutionen för epidemiologi och global hälsa.
    Impact of an oral care subsidization reform on intersectional inequities in self-rated oral health in Sweden2024Inngår i: International Journal for Equity in Health, E-ISSN 1475-9276, Vol. 23, nr 1, artikkel-id 63Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Oral health in Sweden is good at the population level, but seemingly with persisting or increasing inequities over the last decades. In 2008, a major Swedish reform introduced universal partial subsidies to promote preventive care and reduce the treatment cost for patients with extensive care needs. This study aimed to apply an intersectional approach to assess the impact of the 2008 subsidization reform on inequities in self-rated oral health among adults in Sweden over the period 2004–2018.

    Methods: Data from 14 national surveys conducted over 2004–2018 were divided into three study periods: pre-reform (2004–2007), early post-reform (2008–2012) and late post-reform (2013–2018). The final study population was 118,650 individuals aged 24–84 years. Inequities in self-rated oral health were examined by intersectional analysis of individual heterogeneity and discriminatory accuracy across 48 intersectional strata defined by gender, age, educational level, income, and immigrant status.

    Results: Overall, the prevalence of poor self-rated oral health decreased gradually after the reform. Gender-, education- and income-related inequities increased after the reform, but no discernible change was seen for age- or immigration-related inequities. The majority of intersectional strata experienced patterns of persistently or delayed increased inequities following the reform.

    Conclusions: Increased inequities in self-rated oral health were found in most intersectional strata following the reform, despite the seemingly positive oral health trends at the population level. Applying an intersectional approach might be particularly relevant for welfare states with overall good oral health outcomes but unsuccessful efforts to reduce inequities.

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  • 43.
    Ardlin, Berit I.
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi.
    Lindholm-Sethson, Britta
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Dahl, Jon E.
    Corrosion of dental nickel-aluminum bronze with a minor gold content-mechanism and biological impact2009Inngår i: Journal of Biomedical Materials Research. Part B - Applied biomaterials, ISSN 1552-4973, E-ISSN 1552-4981, Vol. 88B, nr 2, s. 465-473Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Objectives: To study corrosion and to evaluate biological effects in vitro of corrosion products of a copper-aluminum-nickel alloy with 2% gold. Methods: The alloy NPGTM+2 with the nominal composition Cu:77.3; Al:7.8; Ni:4.3; Fe:3.0; Zn:2.7; Au:2.0; and Mn:1.7 was characterized. Static immersion in acidic saline, pH 2.2-2.4, was used to determine release of metallic elements in a milieu simulating the condition of plaque build-up in interproximal areas of the tooth. Corrosion and surface reactions in saline and artificial saliva were studied by electrochemical techniques including registration of open-circuit-potentials, polarization curves and impedance spectra. Extracts were made in cell culture media and acidic saline and used for MTT test for cytotoxicity and HET-CAM method for irritation. Results: The mean amount of elements released in the acidic saline were in g cm-2 : Cu:632; Al:210; Ni:144; Fe:122; Zn:48; Mn:52. No protective film was formed on the surface of the alloy, as extensive corrosion was observed in both saline and artificial saliva. The corrosion rate was higher in saline than in artificial saliva. Acidic extracts of the alloy diluted up to 64 times reduced cell viability with 80% or more. The extract induced coagulation of the blood vessels of the CAM and was rated as moderate irritant solution. Significance: The nickel-aluminum bronze showed high corrosion rate caused by an inability to create a protective surface layer. High levels of toxic elements were found after static immersion testing, and the corrosion products had a distinct adverse effect on the biological activity.

  • 44.
    Asalya, Adam
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Tandläkarutbildning.
    Amaya, Mohammed Ali
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Tandläkarutbildning.
    Saliva and Tooth Biofilm Microbiota – Tissue and Temporal Evaluations2022Independent thesis Basic level (university diploma), 20 poäng / 30 hpOppgave
    Abstract [en]

    Abstract

    Background: The oral cavity, similar to other body sites, harbours several site-specific microbiota communities, but there is a large variation in what sample researchers choose to represent the oral microbiome.

    Aim: This project aimed to characterize and compare the bacteria profiles in whole chewing stimulated saliva and pooled tooth biofilm and compare the profiles after 1, 2, or 3 days without oral hygiene. 

    Methods: Six healthy young women and men volunteered to participate. Whole chewing stimulated saliva and tooth biofilm from 16 sites were collected after 1, 2 or 3 days without oral hygiene. Samples were collected into DNA preserving buffer and stored at -80°C until genomic DNA was extracted, purified, and quality controlled. The bacteria profiles were determined by 16S rRNA amplicon sequencing in each sample, Taxonomic classification was done against the eHOMD database.

    Results: There was a distinct separation of the bacteria profiles in tooth biofilm and saliva samples. The tooth biofilm composition variation was larger than that in saliva. Some species dominated in tooth biofilm and saliva microbiota, respectively, and others were in common. Microbiota in saliva and tooth biofilm showed temporal trends.

    Conclusions: The present study gave us more understanding of the variation of the oral bacterial communities and the importance of collection standardization in oral microbiota studies. Thus, the decision on which sample type to use and where and when to sample should be carefully considered in studies on the oral microbiota concerning e.g., caries or periodontitis.

  • 45.
    Asalya, Dalya
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Tandläkarutbildning.
    Abo Khalaf, Haya
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Tandläkarutbildning.
    The influence of titanium ions on the pro-inflammatory response caused by four oral pathogens in vitro2023Independent thesis Advanced level (degree of Master (One Year)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Background: Today usage of titanium implants to replace missing teeth has become a standard treatment. This also means that more individuals are more likely to suffer from peri-implantitis. During the insertion of implants, particles are released in the soft tissue, which might cause inflammation in presence of gram-negative and positive bacteria from the oral cavity.

    Aim: To evaluates the effect of some oral bacteria: Porphyromonas gingivalis (Pg), Parvimonas micra (Pm), Prevotella intermedia (Pi) and Fusobacterium nucleatum (Fn) on the Ti- induced cytotoxicity and pro-inflammatory response in cultures of human macrophages.

    Materials & Methods: This study involves THP-1 cells exposed to four selected bacteria in two different ratios per target cell (MOI 10 or 25). THP- 1 cells were exposed to the following 10 test-groups; Control (Co), Titanium (Ti), Pg, Pm, Pi and Fn, Pg for 24 h + Ti, Pm + Ti for 24 h or Pg, Pi and Fn for 48 h + Ti the last 24 h.Viability of the exposed macrophage cell line (THP-1 cells) was determined by neutral red uptake staining. Enzyme- Linked Immunosorbent Assay method (ELISA) for quantification of IL-1β secretion.

    Results: The Titanium induced IL-1β secretion from the exposed THP-1 cells was substantially enhanced in presence of all the tested periodontitis associated bacteria. Cell viability was not affected in the presence of Ti alone nor together with the different bacteria. In opposite, viability test indicates an enhanced survival to the Ti-induced THP-1 cells in presence of bacteria.

    Conclusion: All the anaerobic bacteria used in the present study increased the Ti-induced release of IL-1β from human macrophages without any significant cytotoxic effect.

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  • 46.
    Asikainen, Sirkka E
    Umeå universitet, Medicinsk fakultet, Odontologi, Oral mikrobiologi.
    Periodontal bacteria and cardiovascular problems.2009Inngår i: Future microbiology, ISSN 1746-0921, Vol. 4, s. 495-498Artikkel i tidsskrift (Annet vitenskapelig)
  • 47.
    Asikainen, Sirkka
    et al.
    Umeå universitet, Medicinsk fakultet, Odontologi.
    Karched, Maribasappa
    Umeå universitet, Medicinsk fakultet, Odontologi.
    Molecular techniques in oral microbial taxonomy, identification and typing2008Inngår i: Molecular Oral Microbiology, Caister Academic Press, Norfolk UK , 2008, s. 1-27Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    The rapid development of molecular techniques during the past decade has revolutionized the field of microbiology. Two issues are of profound importance. First, the discovery of phylogenetically informative DNA sequences, such as the 16S rRNA gene, radically changed the concept of bacterial relatedness and provided a universal system for bacterial identification and categorization. Second, it became possible to detect, identify, and type bacteria independent of their cultivability and, by these new means, to elucidate the diversity and spatial organization of complex oral bacterial communities. Of considerable benefit has been the fact that the same nucleic acid-based molecular approaches can be applied in all microbial environments, ranging from the oral cavity, to the surfaces of historical monuments, to the depths of open oceans. This has led to development of versatile PCR- and hybridization-based techniques that allow a rapid and convenient analysis of the bacterial contents of oral samples and offer previously unattainable possibilities for expanding studies on bacterial epidemiology and characterization. In particular, the emerging new microarray technology will facilitate great strides in understanding the structure and dynamics of oral bacterial communities and bacteria-host interactions, and will form the basis for developing novel diagnostics for oral infections.

  • 48.
    Asplund, Kjell
    Umeå universitet, Medicinska fakulteten, Institutionen för folkhälsa och klinisk medicin, Medicin.
    Hur kan tandhälsans stora gap bestå?2017Inngår i: Tandläkartidningen, ISSN 0039-6982, nr 2, s. 37-37Artikkel i tidsskrift (Annet vitenskapelig)
  • 49.
    Assani, Bashar
    et al.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Tandläkarutbildning.
    Hamza, Ibrahim
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Tandläkarutbildning.
    Dental Caries and Self-Reported Type 2 Diabetes2023Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    ABSTRACT

    Patients with poorly controlled blood sugar levels and type 2 diabetes have been suggested to be at greater risk of tooth decay; however, the number of studies on this topic is scarce. This study aims to evaluate the association between self-reported diabetes, blood sugar levels, and dental caries in Swedish 40-year-old Swedes.

    Here we utilized the Gene Lifestyle Interactions in Dental Diseases (GLIDE) database, which provides access to self-reported diabetes, blood sugar levels, and the Decay, Missing, Filled Surfaces (DMFS) status in approximately 90,000 individuals. For this study, we identified 1,617 self-reported diabetes patients, and for each case, two sex- and age-matched controls were randomly selected (n = 3,234). Logistic and linear regression were employed, with appropriate adjustment for age, sex, and years between the dental caries examination and the reported diabetic diagnosis.

    Patients with self-reported type 2 diabetes displayed a 2.2 DMFS increase (p = 0.019). Additionally, increased blood sugar levels were associated with self-reported type (p < 0.001) and an increased DMFS score (p < 0.001).

    In conclusion, patients with self-reported type 2 diabetes and poorly controlled blood sugar are associated with an increased DMFS score in Sweden.

    Fulltekst (pdf)
    fulltext
  • 50. Astvaldsdottir, Alfheidur
    et al.
    Dagerhamn, Jessica
    van Dijken, Jan W. V.
    Umeå universitet, Medicinska fakulteten, Institutionen för odontologi, Tandhygienistutbildning.
    Naimi-Akbar, Aron
    Sandborgh-Englund, Gunilla
    Tranaeus, Sofia
    Nilsson, Mikael
    Longevity of posterior resin composite restorations in adults: A systematic review2015Inngår i: Journal of Dentistry, ISSN 0300-5712, E-ISSN 1879-176X, Vol. 43, nr 8, s. 934-954Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Objective: To conduct a systematic review of the literature on the longevity of posterior resin composite restorations in adults. Material and methods: A systematic literature search was conducted according to predetermined criteria for inclusion and exclusion. The studies selected were prospective clinical trials with a minimum follow-up time of 4 years, 40 restorations per experimental group and an annual attrition rate of less than 5%. Initially, abstracts and full-text articles were assessed independently and the assessment was subsequently agreed on by five reviewers. The methodological quality of the studies was assessed according to the Swedish Council on Health Technology Assessment (SBU) standard checklist for determining the extent to which studies meet basic quality criteria. Results: In all, the literature search identified 4275 abstracts and 93 articles were read in fulltext. There were eighteen studies which met the criteria for inclusion, eight of which were included in the analysis. There were 80 failures of restorations with a total follow-up time at risk for failure of 62,030 months. The overall incidence rate for all causes of failure was 1.55 lost restorations per 100 restoration years. The most common biological reason for failure (a total of 31 restorations) was secondary caries, with or without fracture of the restoration. The quality of the evidence was low. Conclusions: In an efficacy setting, the overall survival proportion of posterior resin composite restorations is high. The major reasons for failure are secondary caries and restoration fracture which supports the importance of adequate follow-up time. Clinical significance: The overall survival proportion of posterior composite restorations was high, but the results cannot be extrapolated to an effectiveness setting. The importance of adequate follow-up time is supported by the finding that secondary caries often occurred after 3 years or later.

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