Antimicrobial Activity in Chitosan-Treated Prosthetic Materials: A Systematic Review.

OBJECTIVE: The antimicrobial effect of prosthetic materials treated with chitosan was systematically reviewed. METHODS: The searches were carried out on PubMed/Medline, Scopus, ISI Web of Science, LILACS, Embase, and Open Grey with searches performed in March 2022. Selection of in vitro studies, data extraction and risk of bias analysis were performed following the PRISMA guidelines and registered at the Open Science Framework. The evaluated prosthetic materials corresponded to PMMA and tissue conditioner, treated with chitosan. RESULTS: After evaluating the eligibility criteria, 11 articles were included for the qualitative synthesis. The evaluated prosthetic materials corresponded to PMMA (n=8) and tissue conditioner (n=3). All studies performed the incorporation of chitosan in the tissue conditioner (n=3). Regarding PMMA, the use of chitosan as a denture cleanser was the most used (n=3), followed by incorporation (n=2), multilayers coating onto PMMA (n=2) and denture adhesive for PMMA (n=1). Chitosan has antimicrobial activity and is effective in the treatment of prosthetic materials in most studies, but it depends on some factors, such as the treatment method, the type and characteristics of the chitosan, the microorganism evaluated, and its form of organization. CONCLUSION: Chitosan showed highly antimicrobial activity and was effective when used in prosthetic materials.

Resin composite class I restorations: a 54-month randomized clinical trial.

The objective of this longitudinal clinical randomized trial was to evaluate the clinical performance of a nanofilled and a nanohybrid resin composite in Class I occlusal restorations of posterior teeth over the course of 54 months. Forty-one adolescents participated in the study. The teeth were restored with Adper Single Bond 2 (3M ESPE) and nanofilled (Filtek Z350, 3M ESPE), nanohybrid (Esthet-X, Dentsply) and microhybrid Filtek Z250 (3M ESPE) used as a control. After 54 months, the restorations were evaluated in accordance with the modified United States Public Health Service criteria. The McNemar and Friedman tests were used for statistical analysis, at a level of significance of 5%. Five failed restorations were observed during the follow-up. A change to unacceptable restoration occurred for one Esthet-X, two Filtek Z350, and two Filtek Z250 restorations, which received the clinically unacceptable score, Charlie, for both anatomic form and marginal adaptation. Secondary caries and postoperative sensitivity occurred in one Filtek Z250 and one Filtek Z350 restoration. When the five evaluation periods (baseline and six, 12, 30, and 54 months) were compared, significant differences were found in the marginal adaptation of Filtek Z250 and Filtek Z350. Significant differences in the roughness criteria (p=0.005) were also observed when the three composites were compared after 54 months (Filtek Z350 > Filtek Z250 > Esthet-X), always within clinically acceptable limits. The materials investigated showed acceptable clinical performance for Class I restoration after 54 months. Long-term reevaluations are necessary for a more detailed analysis of these composites.

Dynamic functional impression technique for severely resorbed alveolar ridges.

The process of bone resorption can reduce the volume of the alveolar crest, which makes may make difficult impression taking of the alveolar tissue and the subsequent fit of a new denture. This clinical report describes a fast and simple technique for impressions of edentulous ridges to replace complete dentures, using a temporary tissue conditioner material on the denture base. The existing denture must cover the whole supporting area and should be in harmony with the adjacent oral structures. This technique reduces the number of steps involved and minimizes treatment time and expenses.