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Molin Thorén, Margareta
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Publications (10 of 17) Show all publications
Lundegren, N., Sohrabi, M. M., Molin Thorén, M. & Akerman, S. (2019). Prosthetic dental restorations in Swedish samples: prevalence and agreement between self-report, clinical findings, and influence on quality of life. Acta Odontologica Scandinavica, 77(4), 296-302
Open this publication in new window or tab >>Prosthetic dental restorations in Swedish samples: prevalence and agreement between self-report, clinical findings, and influence on quality of life
2019 (English)In: Acta Odontologica Scandinavica, ISSN 0001-6357, E-ISSN 1502-3850, Vol. 77, no 4, p. 296-302Article in journal (Refereed) Published
Abstract [en]

Objective: To determine the prevalence of dental prosthetic restorations in an adult population, to study the agreement between self-reports and clinical findings of prosthetic restorations, and to study answers from a questionnaire in relation to the prevalence of prosthetic restorations. Material and methods: A questionnaire was sent to a sample of 10,000 adults. A further sample of 1000 individuals was invited to answer the questionnaire and also participate in a clinical study. The agreement between self-report and clinical findings was analyzed, as were the associations between prosthetic restorations and questionnaire responses, using the chi(2) test. Results: A total of 40% of the sample had fixed dental prostheses (FDP), 2.7% had removable dentures. The agreement between self-report and clinical findings was 93%. 34.7% of the individuals with no prosthetic restorations were university graduates and 4% of individuals with removable complete dentures. Oral health had the greatest impact on the quality of life of younger individuals with FDP, with an OHIP-14 (Oral Health Impact Profile) score of 7.3 for the age group 20-39 years compared to 4.9 for the age group 65-89 years. Conclusion: The questionnaire method can be a cost-effective way to determine the prevalence of prosthetic restorations.

Place, publisher, year, edition, pages
TAYLOR & FRANCIS LTD, 2019
Keywords
Self-assessment, quality of life, agreement, fixed partial dentures, removable dentures
National Category
Dentistry
Identifiers
urn:nbn:se:umu:diva-158937 (URN)10.1080/00016357.2018.1542505 (DOI)000465152500009 ()30600743 (PubMedID)
Available from: 2019-05-27 Created: 2019-05-27 Last updated: 2019-05-27Bibliographically approved
Pettersson, M., Pettersson, J., Johansson, A. & Molin Thorén, M. (2019). Titanium release in peri-implantitis. Journal of Oral Rehabilitation, 46(2), 179-188
Open this publication in new window or tab >>Titanium release in peri-implantitis
2019 (English)In: Journal of Oral Rehabilitation, ISSN 0305-182X, E-ISSN 1365-2842, Vol. 46, no 2, p. 179-188Article in journal (Refereed) Published
Abstract [en]

Objectives: The aim of this study was to investigate the titanium (Ti) content of biopsies from patients with severe peri-implantitis or periodontitis and to examine whether Ti particles can be identified in samples from peri-implantitis lesions.

Background: Long-term follow-up studies show that implant usage to replace missing or lost teeth is a safe and predictable treatment. However, inflammation and loss of supporting bone around an implant (peri-implantitis) lead to patient suffering and costs. Peri-implantitis is considered to be an infectious disease, but recent studies have shown that Ti can aggravate inflammation in combination with bacterial products. The Ti content of peri-implantitis and periodontitis tissue is unknown.

Methods: Thirteen patients referred for peri-implantitis and eleven for periodontitis treatment were included in the study. Disease severity was obtained from dental records. Biopsies were taken from both groups and chemically analyzed with inductively coupled plasma mass spectrometry (ICP-MS) for Ti content. Additionally, two patients with peri-implantitis and two with periodontitis were recruited and their biopsies were analyzed microscopically with light microscopy (LM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) with element analysis to investigate the presence of particulate Ti.

Results: All patients lost one or more implants despite undergoing peri-implant or periodontal treatment. Peri-implantitis tissue contained significantly higher concentrations of Ti than periodontitis tissue with a mean ± SDof 98.7 ± 85.6 μg/g and 1.2 ± 0.9 μg/g, respectively. Particulate metal was identified in peri-implantitis and periodontitis biopsies, but element analyses could confirm only the presence of Ti in peri-implantitis tissue. The mean size ± SDof the visible particles with LM was 10.9 ± 35.7 μm2 (mean of three repeated measurements) (95% CI, 6.5-15.3).

Conclusion: We showed that high contents of particulate and submicron Ti were present in peri-implantitis tissue. These high Ti contents in peri-implant mucosa can potentially aggravate inflammation, which might reduce the prognosis of treatment interventions.

Place, publisher, year, edition, pages
John Wiley & Sons, 2019
Keywords
energy dispersive X-ray spectroscopy, inductively coupled plasma mass spectrometry, light microscopy, peri-implantitis, scanning electron microscopy, titanium
National Category
Dentistry
Research subject
Odontology
Identifiers
urn:nbn:se:umu:diva-147118 (URN)10.1111/joor.12735 (DOI)000455483300010 ()30325523 (PubMedID)
Funder
Västerbotten County Council, VLL 1147-2014
Note

Originally included in thesis in manuscript form.

Available from: 2018-04-27 Created: 2018-04-27 Last updated: 2019-02-08Bibliographically approved
Pettersson, M., Pettersson, J., Molin Thorén, M. & Johansson, A. (2018). Effect of cobalt ions on the interaction between macrophages and titanium. Journal of Biomedical Materials Research. Part A (9), 2518-2530
Open this publication in new window or tab >>Effect of cobalt ions on the interaction between macrophages and titanium
2018 (English)In: Journal of Biomedical Materials Research. Part A, ISSN 1549-3296, E-ISSN 1552-4965, no 9, p. 2518-2530Article in journal (Refereed) Published
Abstract [en]

Inflammation and bone reduction around dental implants are described as periimplantitis and can be caused by an inflammatory response against bacterial products and toxins. Titanium (Ti) forms aggregates with serum proteins, which activate and cause release of the cytokine interleukin (IL-1β) from human macrophages. It was hypothesized that cobalt (Co) ions can interact in the formation of pro-inflammatory aggregates, formed by titanium. To test this hypothesis, we differentiated THP-1 cells into macrophages and exposed them to Ti ions alone or in combination with Co ions to investigate if IL-1β release and cytotoxicity were affected. We also investigated aggregate formation, cell uptake and human biopsies with inductively coupled plasma atomic emission spectroscopy (ICP-AES) and electron microscopy. Co at a concentration of 100 μM neutralized the IL-1β release from human macrophages and affected the aggregate formation. The aggregates formed by Ti could be detected in the cytosol of macrophages. In the presence of Co, the Ti-induced aggregates were located in the cytosol of the cultured macrophages, but outside the lysosomal structures. It is concluded that Co can neutralize the Ti-induced activation and release of active IL-1β from human macrophages in vitro. Also, serum proteins are needed for the formation of metal-protein aggregates in cell medium. Furthermore, the structures of the aggregates as well as the localization after cellular uptake differ if Co is present in a Ti solution. Phagocytized aggregates with a similar appearance seen in vitro with Ti present, were also visible in a sample from human peri-implant tissue.

Place, publisher, year, edition, pages
John Wiley & Sons, 2018
Keywords
titanium, cobalt, interleukin-1β, peri-implantitis, aggregate formation
National Category
Dentistry
Research subject
Odontology
Identifiers
urn:nbn:se:umu:diva-147124 (URN)10.1002/jbm.a.36447 (DOI)000445615600016 ()29708655 (PubMedID)
Funder
Västerbotten County Council, VLL 1147-2014
Available from: 2018-04-27 Created: 2018-04-27 Last updated: 2018-12-05Bibliographically approved
Karlsson, K., Derks, J., Håkansson, J., Wennström, J. L., Molin Thorén, M., Petzold, M. & Berglundh, T. (2018). Technical complications following implant-supported restorative therapy performed in Sweden. Clinical Oral Implants Research, 29(6), 603-611
Open this publication in new window or tab >>Technical complications following implant-supported restorative therapy performed in Sweden
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2018 (English)In: Clinical Oral Implants Research, ISSN 0905-7161, E-ISSN 1600-0501, Vol. 29, no 6, p. 603-611Article in journal (Refereed) Published
Abstract [en]

Objective: The aim of this study was to evaluate the occurrence and consequences of technical complications in implant-supported restorative therapy.

Material & Methods: The occurrence and consequences of technical complications in implant-supported restorative therapy over a mean follow-up period of 5.3years were assessed based on documentation in files from 2,666 patients. Risk indicators were identified by the use of survival models, considering repeated events. Results were expressed as hazard ratios (HR) including 95% confidence intervals.

Results: Technical complications occurred in 24.8% of the patients. Chipping and loss of retention were the most common, affecting 11.0% and 7.9% of supraconstructions, respectively, while implant-related complications (e.g., implant fracture) were rare. More than 50% of the affected patients experienced technical complications more than once and almost all reported complications led to interventions by a dental professional. The extent of the supraconstruction was the strongest risk indicator for both chipping (HR<0.2) and loss of retention (HR>3).

Conclusion: Over a 5-year period, technical complications in implant-supported restorative therapy occurred frequently and their management required professional intervention.

Place, publisher, year, edition, pages
John Wiley & Sons, 2018
Keywords
diagnosis, clinical assessment, epidemiology, prosthodontics
National Category
Dentistry
Identifiers
urn:nbn:se:umu:diva-150486 (URN)10.1111/clr.13271 (DOI)000439498900008 ()29923628 (PubMedID)
Funder
Swedish Social Insurance AgencySwedish Research Council, 2016-01571
Available from: 2018-08-13 Created: 2018-08-13 Last updated: 2018-08-13Bibliographically approved
Pettersson, M., Pettersson, J., Molin Thorén, M. & Johansson, A. (2017). Release of titanium after insertion of dental implants with different surface characteristics: an ex vivo animal study. Acta Biomaterialia Odontologica Scandinavica, 3(1), 63-73
Open this publication in new window or tab >>Release of titanium after insertion of dental implants with different surface characteristics: an ex vivo animal study
2017 (English)In: Acta Biomaterialia Odontologica Scandinavica, ISSN 0001-5369, E-ISSN 2333-7931, Vol. 3, no 1, p. 63-73Article in journal (Refereed) Published
Abstract [en]

In the present study, amount of titanium (Ti) released into the surrounding bone during placement of implants with different surface structure was investigated. Quantification of Ti released during insertion from three different implants was performed in this ex vivo study. Jaw bone from pigs was used as model for installation of the implants and Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) was used for analysis of the released Ti. Implant surface were examined with scanning electron microscopy (SEM), before and after the placement into the bone. Ti was abraded to the surrounding bone upon insertion of a dental implant and the surface roughness of the implant increased the amount of Ti found. Diameter and total area of the implant were of less importance for the Ti released to the bone. No visible damages to the implant surfaces could be identified in SEM after placement.

Place, publisher, year, edition, pages
Taylor & Francis, 2017
Keywords
titanium, dental implants, inductively coupled plasma atomic emission spectroscopy (ICP-AES)
National Category
Dentistry
Research subject
biological chemistry
Identifiers
urn:nbn:se:umu:diva-143106 (URN)10.1080/23337931.2017.1399270 (DOI)29242814 (PubMedID)
Available from: 2017-12-16 Created: 2017-12-16 Last updated: 2018-06-09Bibliographically approved
Pettersson, M., Kelk, P., Belibasakis, G. N., Bylund, D., Molin Thorén, M. & Johansson, A. (2017). Titanium ions form particles that activate and execute interleukin-1β release from lipopolysaccharide-primed macrophages. Journal of Periodontal Research, 52(1), 21-32
Open this publication in new window or tab >>Titanium ions form particles that activate and execute interleukin-1β release from lipopolysaccharide-primed macrophages
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2017 (English)In: Journal of Periodontal Research, ISSN 0022-3484, E-ISSN 1600-0765, Vol. 52, no 1, p. 21-32Article in journal (Refereed) Published
Abstract [en]

BACKGROUND AND OBJECTIVE: Peri-implantitis is a destructive inflammatory process characterized by destruction of the implant-supporting bone. Inflammasomes are large intracellular multiprotein complexes that play a central role in innate immunity by activating the release of proinflammatory cytokines. Although inflammasome activation has previously been linked to periodontal inflammation, there is still no information on a potential association with peri-implantitis. The aim of this study was to examine cytotoxic and proinflammatory effects, including inflammasome activation, of metals used in dental implants, in an in vitro model, as well as from clinical tissue samples.

MATERIAL AND METHODS: Human macrophages were exposed to different metals [titanium (Ti), cobalt, chromium and molybdenum] in a cell-culture assay. Cytotoxicity was determined using the neutral red uptake assay. Cytokine secretion was quantified using an ELISA, and the expression of genes of various inflammasome components was analysed using quantitative PCR. In addition, the concentrations of interleukin-1β (IL-1β) and Ti in mucosal tissue samples taken in the vicinity of dental implants were determined using ELISA and inductively coupled plasma mass spectrometry, respectively.

RESULTS: Ti ions in physiological solutions stimulated inflammasome activation in human macrophages and consequently IL-1β release. This effect was further enhanced by macrophages that have been exposed to lipopolysaccharides. The proinflammatory activation caused by Ti ions disappeared after filtration (0.22 μm), which indicates an effect of particles. Ti ions alone did not stimulate transcription of the inflammasome components. The Ti levels of tissue samples obtained in the vicinity of Ti implants were sufficiently high (≥ 40 μm) to stimulate secretion of IL-1β from human macrophages in vitro.

CONCLUSION: Ti ions form particles that act as secondary stimuli for a proinflammatory reaction.

Place, publisher, year, edition, pages
John Wiley & Sons, 2017
Keywords
caspase-1, inflammation, interleukin-1β, macrophage, peri-implantitis, titanium
National Category
Medical Biotechnology Dentistry
Research subject
Odontology
Identifiers
urn:nbn:se:umu:diva-118473 (URN)10.1111/jre.12364 (DOI)000393165200003 ()26987886 (PubMedID)
Available from: 2016-03-21 Created: 2016-03-21 Last updated: 2018-06-07Bibliographically approved
Falk, A., von Steyern, P. V., Franssori, H. & Thoren, M. M. (2015). Reliability of the Impression Replica Technique. International Journal of Prosthodontics, 28(2), 179-180
Open this publication in new window or tab >>Reliability of the Impression Replica Technique
2015 (English)In: International Journal of Prosthodontics, ISSN 0893-2174, E-ISSN 1139-9791, Vol. 28, no 2, p. 179-180Article in journal (Refereed) Published
Abstract [en]

The aim of this study was to evaluate the reliability of the impression replica technique with a four-unit zirconia fixed dental prosthesis (FOP). Marginal and internal fit were measured by repeatedly placing the FDP on an epoxy cast using light-body silicone material corresponding to cement. All measured marginal and internal fit points showed varying values. The greatest variations were seen at the most distal margin (33 mu m) and at the distal abutment of the FDP (77 mu m). The results showed that the technique gives moderate variations and is a useful method to evaluate marginal and internal fit.

National Category
Dentistry
Identifiers
urn:nbn:se:umu:diva-102371 (URN)000351890000012 ()25822305 (PubMedID)
Available from: 2015-05-28 Created: 2015-04-23 Last updated: 2018-06-07Bibliographically approved
Molin, M. K. & Karlsson, S. L. (2008). Five-year clinical prospective evaluation of zirconia-based Denzir 3-unit FPDs. International Journal of Prosthodontics, 21(3), 223-227
Open this publication in new window or tab >>Five-year clinical prospective evaluation of zirconia-based Denzir 3-unit FPDs
2008 (English)In: International Journal of Prosthodontics, ISSN 0893-2174, E-ISSN 1139-9791, Vol. 21, no 3, p. 223-227Article in journal (Refereed) Published
Abstract [en]

Purpose: The aim of this prospective study was to evaluate the clinical performance of fully sintered hot isostatic pressed yttria-partially-stabilized zirconia (Denzir) 3-unit fixed partial dentures (FPDs).

Materials and Methods: Nineteen 3-unit FPDs were placed in 18 patients. Ten FPDs were placed in the maxilla and 9 in the mandible. Two calibrated examiners evaluated the FPDs independently 1 week (baseline), 1 year, 3 years, and 5 years after placement using the California Dental Association quality evaluation system.

Results: All FPDs were intact at the 5-year examination. One FPD lost retention after 12 months but remained intact; it was recemented and is still in function after 5 years. All FPDs were rated satisfactory over 5 years. No changes were seen in terms of color and anatomic form. The number of slightly rough or pitted occlusal surfaces increased approximately 30% over 5 years. Visible evidence of ditching along the margin increased over time, but only for those FPDs luted with zinc phosphate cement.

Conclusion: The 5-year results indicate that yttria-partially-stabilized zirconia 3-unit FPDs with anatomically designed frameworks are promising prosthetic alternatives, even in the premolar and molar regions. However, for all-ceramic FPDs with more units in function, further studies are necessary.

Place, publisher, year, edition, pages
Hanover Park: Quintessence Publishing, 2008
Keywords
fixed partial dentures, all-ceramic crowns, fracture-resistance, posterior FPDs, follow-up, bridges, performance, lifetime
National Category
Dentistry
Identifiers
urn:nbn:se:umu:diva-117500 (URN)000256156000008 ()18548960 (PubMedID)
Available from: 2016-03-02 Created: 2016-03-01 Last updated: 2018-06-07Bibliographically approved
Dijken, J. W. .., Ardlin, B., Tillberg, A., Wahlin, Y. B., Berglund, A., Sunnegårdh-Grönberg, K., . . . Hulterström, A. K. (2008). Samarbete breddar forskning: Oral Biomaterialgruppen, Umeå. Tandläkartidningen, 100(5), 74-79
Open this publication in new window or tab >>Samarbete breddar forskning: Oral Biomaterialgruppen, Umeå
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2008 (Swedish)In: Tandläkartidningen, Vol. 100, no 5, p. 74-79Article in journal (Other (popular science, discussion, etc.)) Published
Abstract [sv]

Vid institutionen för odontologi vid Umeå Universitet finns en lång tradition av biomaterialforskning. För drygt två år sedan samlades större delen av den forskningen i ett vetenskapligt nätverk. Här beskrivs ett axplock av det breda forskningsarbetet.

Place, publisher, year, edition, pages
Sveriges Tandläkarförbund, 2008
National Category
Dentistry
Identifiers
urn:nbn:se:umu:diva-10009 (URN)
Available from: 2008-06-09 Created: 2008-06-09 Last updated: 2018-06-09Bibliographically approved
Ahlgren, C., Molin, M., Lundh, T. & Nilner, K. (2007). Levels of gold in plasma after dental gold inlay insertion.. Acta odontologica Scandinavica, 65(6), 331-4
Open this publication in new window or tab >>Levels of gold in plasma after dental gold inlay insertion.
2007 (English)In: Acta odontologica Scandinavica, ISSN 1502-3850, Vol. 65, no 6, p. 331-4Article in journal (Refereed) Published
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.

Keywords
Analysis; delayed hypersensitivity; gold (Au); plasma
National Category
Dentistry
Identifiers
urn:nbn:se:umu:diva-19337 (URN)10.1080/00016350701721772 (DOI)17952707 (PubMedID)
Available from: 2009-03-11 Created: 2009-03-05 Last updated: 2018-06-09
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