Fracture resistance of root-filled teeth after cavity preparation with conventional burs

Abstract

PurposeThe aim of the present study is to compare the fracture resistance of teeth afteraccess cavity preparation with conventional rotary burs, Erbium-doped yttriumaluminum garnet laser (Er:YAG) and Erbium, cromium: yttrium scandium galliumgarnet laser (Er,Cr:YSGG) lasers.Materials and methodsFifty five intact mandibular molars were divided into 3 negative groups (groups 1, 2,3; n=5 for each), 3 study groups (groups 4, 5, 6; n=10 for each) and 1 positive controlgroup (intact teeth; n=10). Access cavities of groups 1, 2 and 3 were prepared withconventional burs, Er:YAG laser and Er,Cr:YSGG laser respectively. After root canalobturation, their coronal portions were left non-restored. Access cavities of groups 4,5 and 6 were prepared by using the same equipment but their coronal portions wererestored with composite resinafter root canal obturation. Following thermocycling,fracture strength was evaluated with a Universal Testing Machine. Mean force at whicheach sample is fractured was recorded in Newton unit and statistically analyzed.ResultsFracture resistance of group 7 (intact teeth) was significantly higher than all othergroups (p<0.001). Differences among the fracture resistance values of groups 4, 5 and 6were not significantly different but they were significantly higher than those of groups1, 2 and 3 (p<0.001). No significant difference was found between Groups 1, 2 and 3.ConclusionPreparing access cavities with either laser or bur has no effect on the fractureresistance of teeth with root canal treatment.

Keywords

• bur
• cavity preparation
• er
• cr:ysgg
• er:yag
• fracture resistance