Comparative analysis of an epoxy resin-based and a premixed calcium silicate-based sealer's push-out bond strength with and without incorporation of chitosan nanoparticles: An in vitro investigation.

Aim and Objectives: The aim of the study was to compare and evaluate the push-out bond strength (POBS) of epoxy resin-based and calcium silicate-based sealers with and without incorporating chitosan nanoparticles (CSNPs). Methodology: Eighty human mandibular premolars with a single canal were taken. A standard root length of 15 mm was established. Canals were instrumented with Neoendo files up to size 30, 4% and were irrigated with 5 ml of 2.5% NaOCl, and 5 ml of ethylenediaminetetraacetic acid 17%. Then, samples were obturated using the size 30, 4% gutta-percha, single-cone technique using respective sealers. For POBS, it was grouped as Group 1 Adseal, Group 2 CeraSeal, Group 3 Adseal + 2% wt/vol CSNP, and Group 4 CeraSeal + 2% wt/vol CSNP. Samples embedded in acrylic resin were sectioned transversely at 11 and 7 mm from the apex. Dislodgment resistance was calculated using a universal testing machine. The data were analyzed using a one-way ANOVA test, followed by Tukey's post hoc analysis. The level of significance (P value) was set at P < 0.05. Results: At 7 mm from the apex, Group 4 (CeraSeal + 2% wt/vol CSNP) demonstrated significantly higher mean POBS. However, no significant difference was observed between Groups 1 (Adseal), Group 2 (CeraSeal), and Group 3 (Adseal + 2% wt/vol CSNP). At 11 mm from the apex, Group 2 (CeraSeal) and Group 4 (CeraSeal + 2% wt/vol CSNP) demonstrated significantly higher mean POBS. On comparison between POBS at 7 mm and 11 mm from the apex, the mean POBS at the 11 mm region from the apex was significantly higher in all study groups, which was statistically significant. Conclusion: Within the limitations of the study, it has been concluded that Group 4 (CeraSeal + 2% wt/vol CSNP) has better bond strength compared to the other groups.

Matrix metalloproteinase inhibitors in restorative dentistry.

Matrix metalloproteinases (MMPs) have been identified as agents that disintegrate the collagen structures of dental hybrid layers, resulting in reduced restorative bond strength. Multiple MMP inhibitors (MMPIs) are known to counteract this degenerative mechanism, thereby preserving bond strength and promoting the longevity of resin-based restorations. Additionally, literature suggests that certain MMPI materials possess antimicrobial/anticariogenic properties, potentially reducing the risk of secondary caries development. Therefore, this review article aims to narrate on the integration of matrix metalloproteinase inhibitors into adhesive systems and their impact on bond strength.

Comparative Evaluation of Fracture Resistance of Fiber-Reinforced Composite and Alkasite Restoration in Class I Cavity.

Background and Aim: Tooth-colored restorative materials for the restoration of decayed posterior teeth continue to gain popularity both among dental practitioners and patients. These materials have undergone a number of improvements in recent years to enhance their physical properties and diversify their use as a restorative material relevant to clinical practice. The aim of this study was to evaluate and compare the fracture resistance of two such advanced restorative materials, namely EverX Posterior, a fiber-reinforced composite and Cention N, an alkasite material in a Class I Cavity. Materials and Methods: Forty intact, caries-free human maxillary premolar teeth extracted for orthodontic purposes were divided randomly into four groups of 10 teeth each. Group I were unprepared teeth (intact teeth); Group II were unrestored teeth with class I cavity; Group III were teeth restored with fiber-reinforced composite (EverX Posterior); and Group IV were teeth restored using alkasite material (Cention N). Fracture resistance was recorded for all samples using a universal testing machine. Results: Higher fracture resistance was recorded in intact teeth group followed by EverX Posterior, Cention N and unrestored teeth, respectively. The teeth restored with EverX Posterior showed higher mean fracture resistance to fractures than those restored with Cention N. Teeth restored with EverX Posterior showed no significant difference in mean fracture resistance from Intact teeth while restored teeth with Cention N and unrestored teeth did. Conclusion: Fracture resistance of EverX Posterior was comparable to that of the natural tooth and was higher as compared to Cention N.