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  • 1.
    De Almeida, Fernando Jose Mota
    et al.
    Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM). Tandvårdens Kompetenscentrum, Norrbotten Public Dental Service, Luleå, Sweden.
    Hassan, Dalya
    Umeå University, Faculty of Medicine, Department of Odontology.
    Abdulrahman, Ghada Nasir
    Umeå University, Faculty of Medicine, Department of Odontology.
    Brundin, Malin
    Umeå University, Faculty of Medicine, Department of Odontology.
    Romani Vestman, Nelly
    Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM). Department of Endodontics, Region of Västerbotten, Sweden.
    CBCT influences endodontic therapeutic decision-making in immature traumatized teeth with suspected pulp necrosis: a before-after study2021In: Dento-Maxillo-Facial Radiology, ISSN 0250-832X, E-ISSN 1476-542X, Vol. 50, no 8, article id 20200594Article in journal (Refereed)
    Abstract [en]

    Objective: To evaluate the impact of cone-beam computed tomography (CBCT) in endodontic therapeutic decision-making of immature traumatized teeth with suspected pulp necrosis.

    Methods: Over two years, consecutive patients with a dental trauma in their front teeth (apex >0.5 mm) and with suspected pulp necrosis based on clinical and radiographic findings were referred to a specialist clinic in Sweden. Fifteen patients aged 6-13 (18 teeth) were included and clinically examined by an endodontist. Intraoral radiographs and CBCT examinations were obtained. Five practitioners, three endodontists and two residents in endodontics, used these examinations to determine the most appropriate treatment for the 18 cases (all central incisors) on two occasions scheduled 19 weeks apart. On the first occasion, the practitioners had access to clinical information and the intraoral radiographs ('before' CBCT); on the second occasion, the practitioners had also access to a radiologist report and the CBCT images ('after' CBCT). Their treatment plans - no treatment, watchful waiting, endodontic orthograde treatment, or extraction - were made anonymously and independently. Results were analysed using descriptive statistics and Wilcoxon signed-rank test.

    Results: 'After' CBCT, practitioners changed treatment plans in 30% of the 90 assessments, 74% of which were more aggressive (p = 0.028). In 49% of the assessments, practitioners who chose the watchful and waiting treatment plan 'before' CBCT changed to a more aggressive therapy such as endodontic orthograde treatment and extraction 'after' CBCT (p = 0.005).

    Conclusion: This study provides evidence that CBCT influences endodontic therapeutic decision-making regarding immature traumatised teeth with suspected pulp necrosis, chiefly when expectant management (i.e., watchful and waiting) was selected before access to CBCT.

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  • 2.
    Holgerson, Pernilla L
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Vestman, Nelly R
    Umeå University, Faculty of Medicine, Department of Odontology.
    Claesson, Rolf
    Umeå University, Faculty of Medicine, Department of Odontology.
    Öhman, Carina
    Umeå University, Faculty of Medicine, Department of Odontology.
    Domellöf, Magnus
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Tanner, Anne CR
    Hernell, Olle
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Johansson, Ingegerd
    Umeå University, Faculty of Medicine, Department of Odontology.
    Oral microbial profile discriminates breast-fed from formula-fed infants2013In: Journal of Pediatric Gastroenterology and Nutrition - JPGN, ISSN 0277-2116, E-ISSN 1536-4801, Vol. 56, no 2, p. 127-136Article in journal (Refereed)
    Abstract [en]

    Objectives: Little is known about the effect of diet on the oral microbiota of infants, although diet is known to affect the gut microbiota. The aims of the present study were to compare the oral microbiota in breast-fed and formula-fed infants, and investigate growth inhibition of streptococci by infant-isolated lactobacilli.

    Methods: A total of 207 mothers consented to participation of their 3-month-old infants. A total of 146 (70.5%) infants were exclusively and 38 (18.4%) partially breast-fed, and 23 (11.1%) were exclusively formula-fed. Saliva from all of their infants was cultured for Lactobacillus species, with isolate identifications from 21 infants. Lactobacillus isolates were tested for their ability to suppress Streptococcus mutans and S sanguinis. Oral swabs from 73 infants were analysed by the Human Oral Microbe Identification Microarray (HOMIM) and by quantitative polymerase chain reaction for Lactobacillus gasseri.

    Results: Lactobacilli were cultured from 27.8% of exclusively and partially breast-fed infants, but not from formula-fed infants. The prevalence of 14 HOMIM-detected taxa, and total salivary lactobacilli counts differed by feeding method. Multivariate modelling of HOMIM-detected bacteria and possible confounders clustered samples from breast-fed infants separately from formula-fed infants. The microbiota of breast-fed infants differed based on vaginal or C-section delivery. Isolates of L plantarum, L gasseri, and L vaginalis inhibited growth of the cariogenic S mutans and the commensal S sanguinis: L plantarum >L gasseri >L vaginalis.

    Conclusions: The microbiota of the mouth differs between 3-month-old breast-fed and formula-fed infants. Possible mechanisms for microbial differences observed include species suppression by lactobacilli indigenous to breast milk.

  • 3. Manoharan, Lokeshwaran
    et al.
    Brundin, Malin
    Umeå University, Faculty of Medicine, Department of Odontology.
    Rakhimova, Olena
    Umeå University, Faculty of Medicine, Department of Odontology.
    de Paz, Luis Chavez
    Romani Vestman, Nelly
    Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM). Department of Endodontics, County Council of Västerbotten.
    New Insights into the Microbial Profiles of Infected Root Canals in Traumatized Teeth2020In: Journal of Clinical Medicine, E-ISSN 2077-0383, Vol. 9, no 12, article id 3877Article in journal (Refereed)
    Abstract [en]

    Traumatic dental injuries in young individuals are often exposed to the invasion of oral microorganisms that leads to pulp necrosis. Infective necrosis in permanent teeth not-fully-developed causes aberrant root formation. Regeneration endodontic treatments (RETs) have shown promising results by promoting continued root development by stem cells. Critical to the success of RET is the thorough disinfection of the pulpal space. To establish effective antimicrobial protocols for root canal disinfection, the invading microorganisms need to be identified. In the present study, we use a combination of culture-based and high-throughput molecular sequencing techniques to investigate the microbial profiles from traumatized teeth (30 cases) and controls, i.e., teeth with pulp infections not caused by trauma (32 cases). Overall, a high microbial diversity in traumatized necrotic teeth was observed. Eubacterium yurii subsps. yurii and margaretiae, as well as key 'bridging oral species' F. nucleatum sp., Polymorphum and Corynebacterium matruchotti, were highly associated with traumatized teeth. The microbial compositions of traumatized teeth differed considerably from those of infected teeth not caused by trauma. Age and tooth position also influence microbial compositions. In conclusion, we show that the root canal microflora of traumatized teeth is highly diverse, and it differs from root canal infections not caused by trauma.

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  • 4.
    Rakhimova, Olena
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Schmidt, Alexej
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Landström, Maréne
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Johansson, Anders
    Umeå University, Faculty of Medicine, Department of Odontology.
    Kelk, Peyman
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Romani Vestman, Nelly
    Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM). Department of Endodontics, County Council of Västerbotten, Umeå, Sweden.
    Cytokine Secretion, Viability, and Real-Time Proliferation of Apical-Papilla Stem Cells Upon Exposure to Oral Bacteria2020In: Frontiers in Cellular and Infection Microbiology, E-ISSN 2235-2988, Vol. 10, article id 620801Article in journal (Refereed)
    Abstract [en]

    The use of stem cells from the apical papilla (SCAPs) has been proposed as a means of promoting root maturation in permanent immature teeth, and plays a significant role in regenerative dental procedures. However, the role of SCAPs may be compromised by microenvironmental factors, such as hypoxic conditions and the presence of bacteria from infected dental root canals. We aim to investigate oral bacterial modulation of SCAP in terms of binding capacity using flow cytometry and imaging, real-time cell proliferation monitoring, and cytokine secretion (IL-6, IL-8, and TGF-β isoforms) under anaerobic conditions. SCAPs were exposed to key species in dental root canal infection, namely Actinomyces gerensceriae, Slackia exigua, Fusobacterium nucleatum, and Enterococcus faecalis, as well as two probiotic strains, Lactobacillus gasseri strain B6 and Lactobacillus reuteri (DSM 17938). We found that A. gerensceriae, S. exigua, F. nucleatum, and E. faecalis, but not the Lactobacillus probiotic strains bind to SCAPs on anaerobic conditions. Enterococcus faecalis and F. nucleatum exhibited the strongest binding capacity, resulting in significantly reduced SCAP proliferation. Notably, F. nucleatum, but not E. faecalis, induce production of the proinflammatory chemokine IL-8 and IL-10 from SCAPs. Production of TGF-β1 and TGF-β2 by SCAPs was dependent on species, cell line, and time, but secretion of TGF-β3 did not vary significantly over time. In conclusion, SCAP response is compromised when exposed to bacterial stimuli from infected dental root canals in anaerobic conditions. Thus, stem cell-mediated endodontic regenerative studies need to include microenvironmental conditions, such as the presence of microorganisms to promote further advantage in the field.

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  • 5.
    Razghonova, Yelyzaveta
    et al.
    Department of Microbiology, Virology and Biotechnology, Mechnikov National University, Odesa, Ukraine.
    Zymovets, Valeriia
    Umeå University, Faculty of Medicine, Department of Odontology.
    Wadelius, Philip
    Department of Endodontics, Region of Västerbotten, Umeå, Sweden.
    Rakhimova, Olena
    Umeå University, Faculty of Medicine, Department of Odontology.
    Manoharan, Lokeshwaran
    National Bioinformatics Infrastructure Sweden (NBIS), Lund University, Lund, Sweden.
    Brundin, Malin
    Umeå University, Faculty of Medicine, Department of Odontology.
    Kelk, Peyman
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Romani Vestman, Nelly
    Umeå University, Faculty of Medicine, Department of Odontology. Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    Transcriptome analysis reveals modulation of human stem cells from the Apical Papilla by species associated with dental root canal infection2022In: International Journal of Molecular Sciences, ISSN 1661-6596, E-ISSN 1422-0067, Vol. 23, no 22, article id 14420Article in journal (Refereed)
    Abstract [en]

    Interaction of oral bacteria with stem cells from the apical papilla (SCAP) can negatively affect the success of regenerative endodontic treatment (RET). Through RNA-seq transcriptomic analysis, we studied the effect of the oral bacteria Fusobacterium nucleatum and Enterococcus faecalis, as well as their supernatants enriched by bacterial metabolites, on the osteo- and dentinogenic potential of SCAPs in vitro. We performed bulk RNA-seq, on the basis of which differential expression analysis (DEG) and gene ontology enrichment analysis (GO) were performed. DEG analysis showed that E. faecalis supernatant had the greatest effect on SCAPs, whereas F. nucleatum supernatant had the least effect (Tanimoto coefficient = 0.05). GO term enrichment analysis indicated that F. nucleatum upregulates the immune and inflammatory response of SCAPs, and E. faecalis suppresses cell proliferation and cell division processes. SCAP transcriptome profiles showed that under the influence of E. faecalis the upregulation of VEGFA, Runx2, and TBX3 genes occurred, which may negatively affect the SCAP’s osteo- and odontogenic differentiation. F. nucleatum downregulates the expression of WDR5 and TBX2 and upregulates the expression of TBX3 and NFIL3 in SCAPs, the upregulation of which may be detrimental for SCAPs’ differentiation potential. In conclusion, the present study shows that in vitro, F. nucleatum, E. faecalis, and their metabolites are capable of up- or downregulating the expression of genes that are necessary for dentinogenic and osteogenic processes to varying degrees, which eventually may result in unsuccessful RET outcomes. Transposition to the clinical context merits some reservations, which should be approached with caution.

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  • 6.
    Romani Vestman, Nelly
    Umeå University, Faculty of Medicine, Department of Odontology.
    Lactobacillus characterization and effects on oral biofilm composition2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The human body is home for millions of bacteria. The largest microbial community is located in the gastro-intestinal (GI) tract, including the oral cavity with >700 identified taxa. Lactobacillus, which is normal inhabitant of the GI tract, contributes to health by possible biofilm and immune modulation. Breast milk is a claimed source for transmittance of Lactobacillus to infants’ GI tract, but there is limited information if breastfeeding affects lactobacilli in the oral cavity. The objectives of Papers I and II of this dissertation were to compare infant oral microbiota by feeding mode, and to characterize oral lactobacilli including potential probiotic properties of the dominant Lactobacillus species.

    Two cohorts with a total of 340 healthy 3- to 4-month-old infants were investigated. Saliva and oral mucosal swab samples were collected. Bacteria were characterized by culture-dependent and -independent methods, including 16S rRNA genes sequencing, quantitative PCR, and the Human Microbe Identification Microarray (HOMIM). Inhibition of growth and adhesion were also tested.

    Multivariate modeling of HOMIM-detected oral bacteria clustered breastfed infants separately from formula-fed infants, and linked breastfed infants to a more health-associated flora. Lactobacilli were essentially detected in breastfed infants only. Lactobacillus gasseri was most prevalent out of six identified Lactobacillus species. Infant isolates of L. gasseri bound to saliva gp340 and MUC7 and adhered to gingival epithelial cells. Infant isolates also inhibited adhesion of Streptococcus mutans to saliva-coated hydroxyapatite, and inhibited growth of S. mutans, Streptococcus sobrinus, Actinomyces naeslundii, Actinomyces oris, Candida albicans and Fusobacterium nucleatum in a concentration-dependent fashion.

    Papers III and IV aimed to assess persistence of probiotic Lactobacillus reuteri, if persistence is necessary for a regrowth of mutans streptococci (MS), and if L. reuteri intake affects oral microbiota composition.

    Two well-documented L. reuteri strains (DSM 17938 and PTA 5289) were used in two double-blind, randomized controlled trials. In the first, 62 subjects (test=32, placebo=30) with high counts of MS were exposed to L. reuteri for 6 weeks. Exposure followed full-mouth disinfection with chlorhexidine. In the second study, 44 healthy subjects (test=22, placebo=22) consumed the L. reuteri for 12 weeks. Saliva and biofilm samples were collected before, during and up to 6 months after exposure. Analyses included culture, strain-specific PCR and 454-pyrosequencing targeting the hypervariable region V3-V4 of the 16S rRNA gene.

    L. reuteri test strains were detected in the mouth of approximately two thirds of test participants during intake. However, their presence decreased gradually when consumption stopped. Subjects with detectable L. reuteri had slower regrowth of MS compared to non-carriers.

    Pyrosequencing yielded a total of 812,547 high-quality sequencing reads. Firmicutes, Proteobacteria, Bacteroidetes, Fusobacteria and Actinobacteria were the major bacterial phyla recovered. Exposure to L. reuteri strains did not affect overall phylotype abundance, but multivariate modeling clustered 12-week-treated test subjects separately from those who received placebo. Exposure to the test strains was strongly associated with presence and increased levels of F. nucleatum and Streptococcus spp.

    In conclusion, the oral microbiota differed by feeding mode in infants. One third of breastfed infants had lactobacilli in the mouth, while only single formula-fed infant had it. L. gasseri, predominant in infants, displayed probiotic characteristics in vitro. Retention of probiotic L. reuteri was a prerequisite for delay of MS regrowth after disinfection. However, probiotic bacteria may not be beneficial for all, since L. reuteri DSM 17938 and PTA 5289 were retained in only 2 of 3 consumers. Finally, the altered microbiota after 12 weeks consumption of L. reuteri indicates that intake of probiotic bacteria, or at least L reuteri, has an impact on oral ecology. However, this finding needs further investigation.

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  • 7.
    Romani Vestman, Nelly
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Chen, Tsute
    Department of Microbiology, The Forsyth Institute, Cambridge, United States of America.
    Lif Holgerson, Pernilla
    Umeå University, Faculty of Medicine, Department of Odontology.
    Öhman, Carina
    Umeå University, Faculty of Medicine, Department of Odontology.
    Johansson, Ingegerd
    Umeå University, Faculty of Medicine, Department of Odontology.
    Oral Microbiota Shift after 12-Week Supplementation with Lactobacillus reuteri DSM 17938 and PTA 5289: A Randomized Control Trial2015In: PLOS ONE, E-ISSN 1932-6203, Vol. 10, no 5, article id e0125812Article in journal (Refereed)
    Abstract [en]

    Background: Lactobacillus spp. potentially contribute to health by modulating bacterial biofilm formation, but their effects on the overall oral microbiota remain unclear.

    Methods and Findings: Oral microbiota was characterized via 454-pyrosequencing of the 16S rDNA hypervariable region V3-V4 after 12 weeks of daily Lactobacillus reuteri DSM 17938 and PTA 5289 consumption. Forty-four adults were assigned to a test group (n = 22) that received lactobacilli lozenges (108 CFU of each strain/lozenge) or a control group that received placebo (n = 22). Presence of L. reuteri was confirmed by cultivation and species specific PCR. Tooth biofilm samples from 16 adults before, during, and after exposure were analyzed by pyrosequencing. A total of 1,310,292 sequences were quality filtered. After removing single reads, 257 species or phylotypes were identified at 98.5% identity in the Human Oral Microbiome Database. Firmicutes, Bacteroidetes, Fusobacteria, Proteobacteria, and Actinobacteria were the most abundant phyla. Streptococcus was the most common genus and the S. oralis/S. mitis/S. mitis bv2/S. infantis group comprised the dominant species. The number of observed species was unaffected by L. reuteri exposure. However, subjects who had consumed L. reuteri were clustered in a principal coordinates analysis relative to scattering at baseline, and multivariate modeling of pyrosequencing microbiota, and culture and PCR detected L. reuteri separated baseline from 12-week samples in test subjects. L. reuteri intake correlated with increased S. oralis/S. mitis/S. mitis bv2/S. infantis group and Campylobacter concisus, Granulicatella adiacens, Bergeyella sp. HOT322, Neisseria subflava, and SR1 [G-1] sp. HOT874 detection and reduced S. mutans, S. anginosus, N. mucosa, Fusobacterium periodicum, F. nucleatum ss vincentii, and Prevotella maculosa detection. This effect had disappeared 1 month after exposure was terminated.

    Conclusions: L. reuteri consumption did not affect species richness but induced a shift in the oral microbiota composition. The biological relevance of this remains to be elucidated.

    Trial Registration: ClinicalTrials.gov NCT02311218

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  • 8.
    Vestman, Nelly Romani
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Hasslöf, Pamela
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Keller, Mette K
    Granström, Elisabeth
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Roos, Stefan
    Twetman, Svante
    Stecksen-Blicks, Christina
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Lactobacillus reuteri influences regrowth of mutans streptococci after full-mouth disinfection: a double-blind, randomised controlled trial2013In: Caries Research, ISSN 0008-6568, E-ISSN 1421-976X, Vol. 47, no 4, p. 338-345Article in journal (Refereed)
    Abstract [en]

    This study assessed whether the persistence of Lactobacillus reuteri DSM 17938 and ATCC PTA 5289 in saliva could delay the regrowth of mutans streptococci (MS) after a full-mouth disinfection with chlorhexidine (CHX). A randomised, double-blind, placebo-controlled study with a 6-week intervention period and 3- and 6-month follow-up was performed. 62 healthy subjects with moderate to high counts of MS were randomly assigned to a test group (n = 32) or a placebo group (n = 30). Before onset of the intervention, subjects received two sessions of professional cleaning, flossing, and application of CHX varnish and rinsed their mouth with a CHX solution between the sessions (2 days). Thereafter, the test group used probiotic lozenges (2/day) containing L. reuteri (DSM 17938 and ATCC PTA 5289; 1 × 108 CFU of each strain), and the placebo group used identical lozenges lacking the lactobacilli. Saliva samples were collected and cultured onto selective media, and isolates of L. reuteri as well as DNA directly extracted from saliva were tested by polymerase chain reaction (PCR) with specific primers. Presence of salivary MS was analysed with a chair-side test. L. reuteri was frequently detected by culture during the intervention period but in only 3 test group subjects at follow-ups. Regrowth of MS statistically significantly differed depending on the presence or absence of L. reuteri DSM 17938 detected by PCR. We conclude that cultivable L. reuteri strains may only sporadically be confirmed after termination of the intervention, but subjects with PCR-detected L. reuteridemonstrated slower regrowth of MS.

  • 9.
    Vestman, Nelly Romani
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Timby, Niklas
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Holgerson, Pernilla Lif
    Umeå University, Faculty of Medicine, Department of Odontology.
    Kressirer, Christine A
    Claesson, Rolf
    Umeå University, Faculty of Medicine, Department of Odontology.
    Domellöf, Magnus
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Öhman, Carina
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Tanner, Anne CR
    Hernell, Olle
    Umeå University, Faculty of Medicine, Department of Clinical Sciences, Paediatrics.
    Johansson, Ingegerd
    Umeå University, Faculty of Medicine, Department of Odontology, School of Dentistry.
    Characterization and in vitro properties of oral lactobacilli in breastfed infants2013In: BMC Microbiology, E-ISSN 1471-2180, Vol. 13, p. 193-Article in journal (Refereed)
    Abstract [en]

    Background: Lactobacillus species can contribute positively to general and oral health and are frequently acquired by breastfeeding in infancy. The present study aimed to identify oral lactobacilli in breast and formula-fed 4 month-old infants and to evaluate potential probiotic properties of the dominant Lactobacillus species detected. Saliva and oral swab samples were collected from 133 infants who were enrolled in a longitudinal study (n=240) examining the effect of a new infant formula on child growth and development. Saliva was cultured and Lactobacillus isolates were identified from 16S rRNA gene sequences. Five L. gasseri isolates that differed in 16S rRNA sequence were tested for their ability to inhibit growth of selected oral bacteria and for adhesion to oral tissues. Oral swab samples were analyzed by qPCR for Lactobacillus gasseri.

    Results: 43 (32.3%) infants were breastfed and 90 (67.7%) were formula-fed with either a standard formula (43 out of 90) or formula supplemented with a milk fat globule membrane (MFGM) fraction (47 out of 90). Lactobacilli were cultured from saliva of 34.1% breastfed infants, but only in 4.7% of the standard and 9.3% of the MFGM supplemented formula-fed infants. L. gasseri was the most prevalent (88% of Lactobacillus positive infants) of six Lactobacillus species detected. L. gasseri isolates inhibited Streptococcus mutans binding to saliva-coated hydroxyapatite, and inhibited growth of S. mutans, Streptococcus sobrinus, Actinomyces naeslundii, Actinomyces oris, Candida albicans and Fusobacterium nucleatum in a concentration dependent fashion. L. gasseri isolates bound to parotid and submandibular saliva, salivary gp340 and MUC7, and purified MFGM, and adhered to epithelial cells. L. gasseri was detected by qPCR in 29.7% of the oral swabs. Breastfed infants had significantly higher mean DNA levels of L. gasseri (2.14 pg/uL) than infants fed the standard (0.363 pg/uL) or MFGM (0.697 pg/uL) formula.

    Conclusions: Lactobacilli colonized the oral cavity of breastfed infants significantly more frequently than formulafed infants. The dominant Lactobacillus was L. gasseri, which was detected at higher levels in breastfed than formula-fed infants and displayed probiotic traits in vitro.

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  • 10.
    Wikström, Alina
    et al.
    Division of Orthodontics and Paediatric Dentistry, Department of Dental Medicine, Karolinska Institute, Stockholm, Sweden; Department of Endodontics, Public Dental Health Services, Eastmaninstitutet, Stockholm, Sweden; Centre of Paediatric Oral Health, Huddinge, Sweden.
    Brundin, Malin
    Umeå University, Faculty of Medicine, Department of Odontology.
    Romani Vestman, Nelly
    Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM). Department of Endodontics, County Council of Västerbotten, Umeå, Sweden.
    Rakhimova, Olena
    Umeå University, Faculty of Medicine, Department of Odontology.
    Tsilingaridis, Georgios
    Division of Orthodontics and Paediatric Dentistry, Department of Dental Medicine, Karolinska Institute, Stockholm, Sweden; Centre of Paediatric Oral Health, Huddinge, Sweden.
    Endodontic pulp revitalization in traumatized necrotic immature permanent incisors: early failures and long-term outcomes—A longitudinal cohort study2022In: International Endodontic Journal, ISSN 0143-2885, E-ISSN 1365-2591, Vol. 55, no 6, p. 630-645Article in journal (Refereed)
    Abstract [en]

    Aim: This prospective cohort study evaluates clinical and radiographical outcomes of endodontic pulp revitalization (PR) of traumatized necrotic incisors.

    Methodology: Pulp revitalization was performed in 75 traumatized necrotic immature incisors from 71 patients. The radiographic outcome measures were continued root formation (width and length), root resorption, apex closure, periapical index, and root development stage. The clinical outcome measures were percussion pain, palpation pain, pathological tooth mobility, swelling, sinus tract, ankylosis, crown discolouration, response to pulp sensitivity test, and subjective pain. Treatment outcomes were categorized as a success based on the absence of clinical symptoms and when radiographic evidence was present for apical healing and continued root development. The performed statistical tests were repeated measures anova, pairwise comparisons of interactions (t-test), McNemar's test, and linear regression model.

    Results: In 45 of 75 teeth (60%), PR was successful with the resolution of clinical and radiographic signs and continued root development. PR failed due to the absence of bleeding (n = 19) and persistent infection (n = 11). PR showed statistically significant increases in root length (11%), and dentinal wall thickness (30%), root maturation (pre-operative 3.38 [CI 1.88; 4.88]; post-operative 4.04, [CI 2.56; 5.52]) apical closure (71.4%), healing of pre-operative apical periodontitis (100%), and healing of pre-operative inflammatory root resorptions (100%). Three predictive variables for continued root maturation were identified – root development stage at entry (p =.0001, β 0.649), [CI 0.431; 0.867], trauma to the soft tissues (p =.026, β −0.012), [CI −0.0225; −0.015], and pre-operative dentinal wall thickness (p =.009, β −0.001); [CI −0.001; 0.0001].

    Conclusions: Our findings indicate that PR provides satisfactory clinical and radiographical outcomes in traumatized necrotic incisors. The failed cases were related to lack of bleeding and persistent infections, indicating that new techniques are needed to improve the predictability of PR.

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  • 11.
    Zymovets, Valeriia
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology.
    Rakhimova, Olena
    Umeå University, Faculty of Medicine, Department of Odontology.
    Wadelius, Philip
    Department of Endodontics, Region of Västerbotten, Umeå, Sweden.
    Schmidt, Alexej
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Brundin, Malin
    Umeå University, Faculty of Medicine, Department of Odontology.
    Kelk, Peyman
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Landström, Maréne
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Romani Vestman, Nelly
    Umeå University, Faculty of Medicine, Department of Odontology. Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM).
    Exploring the impact of oral bacteria remnants on stem cells from the Apical papilla: mineralization potential and inflammatory response2023In: Frontiers in Cellular and Infection Microbiology, E-ISSN 2235-2988, Vol. 13, article id 1257433Article in journal (Refereed)
    Abstract [en]

    Introduction: Bacterial persistence is considered one of the main causal factors for regenerative endodontic treatment (RET) failure in immature permanent teeth. This interference is claimed to be caused by the interaction of bacteria that reside in the root canal with the stem cells that are one of the essentials for RET. The aim of the study was to investigate whether prolonged exposure of stem cells from the apical papilla (SCAP) to bacterial remnants of Fusobacterium nucleatum, Actinomyces gerensceriae, Slackia exigua, Enterococcus faecalis, Peptostreptococcaceae yurii, commonly found in infected traumatized root canals, and the probiotic bacteria Lactobacillus gasseri and Limosilactobacillus reuteri, can alter SCAP’s inflammatory response and mineralization potential.

    Methods: To assess the effect of bacterial remnants on SCAP, we used UV-C–inactivated bacteria (as cell wall-associated virulence factors) and bacterial DNA. Histochemical staining using Osteoimage Mineralization Assay and Alizarin Red analysis was performed to study SCAP mineralization, while inflammatory and osteo/odontogenic-related responses of SCAPs were assessed with Multiplex ELISA.

    Results: We showed that mineralization promotion was greater with UV C–inactivated bacteria compared to bacterial DNA. Immunofluorescence analysis detected that the early mineralization marker alkaline phosphatase (ALP) was increased by the level of E. coli lipopolysaccharide (LPS) positive control in the case of UV-C–inactivated bacteria; meanwhile, DNA treatment decreased the level of ALP compared to the positive control. SCAP’s secretome assessed with Multiplex ELISA showed the upregulation of pro-inflammatory factors IL-6, IL-8, GM-CSF, IL-1b, neurotrophic factor BDNF, and angiogenic factor VEGF, induced by UV-C–killed bacteria.

    Discussion: The results suggest that long term stimulation (for 21 days) of SCAP with UV-C–inactivated bacteria stimulate their mineralization and inflammatory response, while DNA influence has no such effect, which opens up new ideas about the nature of RET failure.

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  • 12.
    Zymovets, Valeriia
    et al.
    Umeå University, Faculty of Medicine, Department of Odontology. Department of Microbiology, Virology and Biotechnology, Mechnikov National University, Odesa, Ukraine.
    Razghonova, Yelyzaveta
    Department of Microbiology, Virology and Biotechnology, Mechnikov National University, Odesa, Ukraine.
    Rakhimova, Olena
    Umeå University, Faculty of Medicine, Department of Odontology.
    Aripaka, Karthik
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Manoharan, Lokeshwaran
    National Bioinformatics Infrastructure Sweden, Lund University, Lund, Sweden.
    Kelk, Peyman
    Umeå University, Faculty of Medicine, Department of Integrative Medical Biology (IMB), Anatomy.
    Landström, Maréne
    Umeå University, Faculty of Medicine, Department of Medical Biosciences, Pathology.
    Romani Vestman, Nelly
    Umeå University, Faculty of Medicine, Wallenberg Centre for Molecular Medicine at Umeå University (WCMM). Department of Endodontics, Region of Västerbotten, Umea, Sweden.
    Combined Transcriptomic and Protein Array Cytokine Profiling of Human Stem Cells from Dental Apical Papilla Modulated by Oral Bacteria2022In: International Journal of Molecular Sciences, ISSN 1661-6596, E-ISSN 1422-0067, Vol. 23, no 9, article id 5098Article in journal (Refereed)
    Abstract [en]

    Stem cells from the apical papilla (SCAP) are a promising resource for use in regenerative endodontic treatment (RET) that may be adversely affected by oral bacteria, which in turn can exert an effect on the success of RET. Our work aims to study the cytokine profile of SCAP upon exposure to oral bacteria and their supernatants—Fusobacterium nucleatum and Enterococcus faecalis—as well as to establish their effect on the osteogenic and immunogenic potentials of SCAP. Further, we target the presence of key proteins of the Wnt/β-Catenin, TGF-β, and NF-κB signaling pathways, which play a crucial role in adult osteogenic differentiation of mesenchymal stem cells, using the Western blot (WB) technique. The membrane-based sandwich immunoassay and transcriptomic analysis showed that, under the influence of F. nucleatum (both bacteria and supernatant), the production of pro-inflammatory cytokines IL-6, IL-8, and MCP-1 occurred, which was also confirmed at the mRNA level. Conversely, E. faecalis reduced the secretion of the aforementioned cytokines at both mRNA and protein levels. WB analysis showed that SCAP co-cultivation with E. faecalis led to a decrease in the level of the key proteins of the Wnt/β-Catenin and NF-κB signaling pathways: β-Catenin (p = 0.0068 *), LRP-5 (p = 0.0059 **), and LRP-6 (p = 0.0329 *), as well as NF-kB (p = 0.0034 **) and TRAF6 (p = 0.0285 *). These results suggest that oral bacteria can up-and downregulate the immune and inflammatory responses of SCAP, as well as influence the osteogenic potential of SCAP, which may negatively regulate the success of RET.

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