ABSTRACT
Objective: This systematic review and meta-analysis aimed to evaluate if bioceramic sealers had superior sealing properties to epoxy resin-based sealers. Methodology: A systematic search was performed in the following databases: MEDLINE Ovid (from 1946 onwards), Scopus, Google Scholar, EBSCO, and a hand search of references of included articles was also done. In vitro and ex vivo studies were included. Risk of bias was assessed, and quantitative synthesis was performed for microleakage measured using vertical dye penetration, horizontal dye penetration, and dentin-sealer gap. Summary effect was reported as Standardized Mean Difference with 95% CI. Subgroup analysis was performed based on the imaging modalities, the obturation techniques, and the file systems employed. Results: A total of 24 studies were included. Meta-analysis demonstrated no significant difference between the sealing ability of bioceramic sealer and epoxy resin-based sealer when measured using the microleakage tests [SMD -0.59(95%CI: 1.74,0.55)]. Subgroup analysis revealed no significant differences except when manual K-files were used. Heterogeneity was low when sub-group analysis was done. Conclusion: Bioceramic sealers and epoxy resin-based sealers both exhibited comparable sealing ability.
ABSTRACT
AIM: The purpose of the study was to evaluate the stress on the implant and to assess the denture displacement for locator and bar and clip attachment types in implant-assisted obturators. MATERIALS AND METHODS: A maxillary edentulous experimental model with a maxillectomy defect was made along with an opposing edentulous mandibular model with self-cure acrylic. Two endosseous implants were placed in the maxillary model. Corresponding obturator complete denture was fabricated for the maxillary model and a complete denture for the mandibular. The attachments were positioned on the implants in maxillary model, and their sleeve/clip was placed on intaglio surface of the dentures. The mounted articulator was placed on a loading apparatus, and force was incrementally applied to it. The strain and displacement for both the attachment types were measured and compared using Digital Image Correlation (DIC). RESULTS: Locator attachment showed the least stress and minimal displacement as compared to bar and clip attachment. CONCLUSION: The stresses around the implants and displacement of the obturator are affected by the attachment type used. It was found that bar and clip (splinted) showed the maximum stresses around the implant and maximum denture displacement. Locator attachment is the better choice over bar and clip because of its additional retentive features. CLINICAL SIGNIFICANCE: The advantage of using DIC over the conventional strain gauge analysis is that a full-field data of displacement and strain can be obtained instead of getting a mean value on the small surface where the strain gauge is positioned.
