The Effect of Cutting Efficacy of Diamond Burs on Microleakage of Class V Resin Composite Restorations Using Total Etch and Self Etch Adhesive Systems

In this study, the effect of bur cutting efficacy was evaluated on microleakageof class V composite restorations with two adhesive systems. Class V cavities were produced on sound extracted human teeth,which had been assigned randomly to one of six groups (N=15) as follows: Groups 1 and 6 were prepared using used rough diamond bur; Group 2 and 5 were prepared using new rough diamond bur; Group 3 and 4 were prepared using soft diamond bur. After application of Single Bond (3M Dental Product, USA) in groups 4,5 and 6 and Clearfil SE Bond [Kurary Medical Inc. Japan] in groups 1,2 and 3, all cavities were restored with composite resin. The teeth were thermocycled and microleakage was evaluated by dye penetration.Kruskal-Wallis and Mann-Whitney tests with Bonferroni's correction were used for statisticalanalysis. The results showed that gingival margins significantly leaked more than occlusalmargins for all bur types and bonding systems. Using the same adhesive system in gingivalmargins, significant difference was seen between bur types and using the same burtype in occlusal margins, there was a significant difference between the two types of adhesive systems. Cutting efficiency of bur had a great effect on microleakage of resin compositerestorations. So long term use of burs may result in an increase in microleakage ofcomposite resin restorations.