Comparing marginal microleakage in Class V cavities restored with flowable composite and Cention-N using confocal microscope-an in-vitro study.

CONTEXT: Class V cavity presents a clinical challenge in the field of restorative dentistry as the margin placement is partially in enamel and partly in cementum, and the trouble associated with this design is the microleakage at the tooth restoration interface. AIMS: To evaluate and compare marginal microleakage in Class V cavities when restored with flowable composite and Cention-N restorative material. METHODS AND MATERIAL: This in-vitro study was performed on 30 human maxillary premolars, which were extracted for orthodontic reasons. Class V cavities were prepared on the buccal surfaces of each tooth. After application of seventh-generation bonding agent (3M ESPE, Single Bond Universal Adhesive), the teeth were divided into two groups of 15 each and restored with flowable composite (3M ESPE Filtek Z350 XT) and Cention-N (Ivoclar Vivadent) and were subjected to thermocycling. The teeth were then immersed in 0.1% Rhodamine B dye for 48 h. They were sectioned longitudinally into mesial and distal parts with the help of an isomet diamond saw. The sections were observed under a confocal laser scanning microscope (CLSM). STATISTICAL ANALYSIS USED: The results were subjected to statistical analysis using the Mann-Whitney U test and Pearson's Chi-square test. RESULTS: The analysis showed statistically significant results among the groups. Cention-N showed lesser microleakage, which was statistically significant when compared to flowable composite (P = 0.005). CONCLUSIONS: Cention-N showed significantly lesser leakage and better adaptation than flowable composite.

Evaluation of effect of different disposable infection control barriers on light intensity of light-curing unit and microhardness of composite - An in vitro study.

AIMS: This study evaluated effect of infection control barriers on light intensity (LI) of light-curing unit (LCU) and microhardness of composite. MATERIALS AND METHODS: Four different disposable barriers (n = 30) were tested against the control. LI for each barrier was measured with Lux meter. One hundred and fifty Teflon molds were equally divided into five groups of thirty each. Composite was filled in bulk in these molds and cured without and with barrier. Microhardness was evaluated on top and bottom surface of composite specimen with microhardness testing machine and hardness ratio (HR) was derived. STATISTICAL ANALYSIS USED: One-way analysis of variance, Tukey's honestly significant difference test, and paired t-test using SPSS version 18 software. RESULTS: All barriers had significantly reduced the baseline LI of LCU (P < 0.0001), but only Cure Elastic Steri-Shield and latex cut glove pieces (LCGP) significantly reduced the microhardness of the composite (P < 0.05). However, HR determined inadequate curing only with LCGP. CONCLUSIONS: Although entire tested barrier significantly reduced the LI; none, except LCGP markedly affected the degree of cure of the composite.