Microleakage Comparative Evaluation of RMGIC and Alkasite with and without Adhesive System in Class V Cavity: An In Vitro Study.

AIM AND OBJECTIVE: This study aimed to compare microleakage of resin-modified glass ionomer cement (RMGIC) and alkasite with and without adhesive system in class V cavity. MATERIALS AND METHODS: Thirty class V cavities were prepared on the buccal surface. All prepared samples were randomly divided into three groups. Group I was restored with RMGIC, group II was restored with Cention N after the application of adhesive system, and group III was restored with alkasite. Samples were subjected to 200 thermocycles between temperature baths at 5ºC and 55ºC. Samples were stained with 2% methylene blue. The teeth were sectioned longitudinally, and the sections were then observed under stereomicroscope at a magnification of 20×. RESULTS: Statistical analysis showed that there was less microleakage in Cention N using adhesive system in both occlusal margin and gingival margin. CONCLUSION: There were significant differences between RMGIC, alkasite with adhesive system, and alkasite without adhesive system in class V cavity. Least microleakage at the occlusal margin and gingival margin was seen with Cention N using adhesive system and highest microleakage at the RMGIC. CLINICAL SIGNIFICANCE: Cention N using the adhesive system affects the microleakage in the class V restoration. The study theorizes that the material restorations showed less microleakage in the occlusal margin than in the gingival margin.

Effect of Different LED Light-curing Units on Degree of Conversion and Microhardness of Bulk-fill Composite Resin.

AIM: The aim of this study is to compare the effect of the use of second-generation and third-generation LED light-curing units (LCUs) on the degree of conversion (DC) and microhardness (VHN) of bulk-fill resin composites. MATERIALS AND METHODS: Thirty cylindrical specimens (each n = 5) of Tetric N-Ceram Bulk-Fill, Filtek™ Bulk-Fill Posterior Restorative, and SDR flow were prepared in metal molds (5 mm in diameter and 4 mm in thickness) and cured with second-generation LED (SmartLite® Focus®, Dentsply Sirona) and third-generation LED (Bluephase® style, Ivoclar Vivadent) resulting in six groups. Degree of conversion was determined using Fourier transform infrared spectroscopy (FTIR), and microhardness with Vickers microhardness tester. Data were statistically analyzed using one-way ANOVA and least significance difference (LSD) test, and DC and microhardness were correlated using Pearson's correlation (α = 0.05). RESULTS: There was a significant difference between DC and VHN between all groups of bulk-fill which were cured by second-generation LED curing light and third-generation LED curing light. Then there is no significant difference between DC of the three composite bulk-fill resins by (second-generation LED vs third-generation LED curing light). CONCLUSION: The second-generation LED curing light can still be used to cure bulk-fill resin composites by increasing the duration of irradiation. CLINICAL SIGNIFICANCE: In the microhardness test, there was a significant difference in the Filtek™ Bulk-Fill Posterior Restorative resin composites.

Comparative Evaluation of Short Fiber-reinforced Composite Resin Thickness on Fracture Resistance of Class II Composite Restoration: An In Vitro Study.

AIM: This study aims to evaluate the difference in fracture resistance of the short fiber-reinforced composite (SFRC) thickness as intermediate layer of class II composite restoration. MATERIALS AND METHODS: Thirty human maxillary premolars were selected and divided into three groups. In groups I, II, and III, class II cavities were prepared. Groups I and II were restored with 2 mm and 4 mm thickness of SRFC as intermediate layer. Group III as control group was restored with nanohybrid composite. Thermocycling procedure was performed manually 250 times. Fracture resistance was measured by using Universal Testing Machine. Data were analyzed statistically using One-way Analysis of Variance (ANOVA) and post hoc least significant difference (LSD) test. RESULTS: The result showed that group II had the highest fracture resistance and group III had the lowest fracture resistance. The difference between groups was statistically significant (p value < 0.05). CONCLUSION: The conclusion showed that adding 4 mm of SFRC as an intermediate layer increased the fracture resistance. CLINICAL SIGNIFICANCE: The use of SFRC as intermediate layer enhanced the fracture resistance of class II composite restoration.