Investigation of the Effect of Bleaching on Discolored Teeth After Regenerative Treatment on Fracture Resistance of Teeth

Abstract

Objective: This study aimed to evaluate the effect of bleaching discolored teeth after regenerative endodontic treatment on fracture resistance. Methods: Forty human maxillary incisors were selected for the study and were divided into four study groups (n=10). Group 1 was called the positive control group, and no treatment was applied. In Group 2; root canals were enlarged to size 6 peezo reamer bur to mimic an immature tooth. The disinfection protocol was performed according to the regenerative endodontic treatment protocol of the American Association of Endodontists. 3 mm thick mineral trioxide aggregate (MTA) was placed at the cementoenamel margin and restored with a temporary restorative material. The samples in group 3 were restored with glass ionomer and composite resin. In Group 4 bleaching was applied with 35% hydrogen peroxide bleaching agent to the samples before restoration with glass ionomer and composite resin. Then each group was applied to the cervical fracture resistance test with a universal testing machine. The fracture resistance values were recorded in Newtons (N), and the obtained data were analyzed statistically. Results: While the highest fracture strength was obtained in group 1 (1092 ±9.27N), the lowest fracture resistance was observed in group 2 (493.8 ±7.60N). The difference between all groups was statistically significant (p<0.05). Conclusion: 35% hydrogen peroxide bleaching agent application after regenerative endodontic treatment reduces fracture resistance of the tooth.