Effect of different layering techniques on microleakage of nanofilled composite in class i restorations: An In Vitro study

[摘要] Aim: To compare effect of different layering techniques on microleakage of nanofilled composites in class I restorations. Materials and Methods: 40 extracted maxillary premolar teeth were assigned to 2 different groups (Group 1 and 2) 20 teeth per group. A Class 1 cavity measuring 3mm´3mm´2mm was prepared in all the teeth. In group 1 and 2 teeth Clearfil TMSE Bond (Kurary Medical inc. Okayama, Japan) was applied. Group 1 teeth were filled with FiltekTM Z350 XT (nanocomposite) (3M ESPE, St Paul, USA) using oblique incremental technique and in Group 2 teeth were filled with FiltekTM Z350 XT (nanocomposite) (3M ESPE, St Paul, USA) using vertical incremental technique and each increment was cured for 30 seconds. Specimens were thermocycled for 1000 cycles (5/55°C,30 seconds) and immersed in 2% methylene blue dye for 24 hours. Following immersion teeth were sectioned and observed under a stereomicroscope. Results were analysed using paired “ t ” test and Mann–Whitney test. Results and Conclusion: The difference between the oblique group and the vertical group was found to be statistically non significant ( P value >0.05) but mean microleakage was more in vertical group compared to oblique group.

[关键词] Microleakage;nanofilled composites;oblique layering technique;vertical layering technique