Background and Aim: This study compared the fracture resistance and esthetic appearance of reattached incisor tooth fragments with different preparation techniques in simulated crown fractures (CFs).
Materials and Methods: In this in vitro study, 50 permanent maxillary incisors were randomly divided into five groups (n=10). After induction of uncomplicated CFs, the fractured teeth were restored using five methods: (I) simple reattachment (SR), (II) circumferential chamfer (CC), (III) buccal scalloped bevel and lingual bevel (BSB&LB), (IV) buccal and lingual overcontour (BO&LO), and (V) buccal scalloped bevel and lingual overcontour (BSB&LO). After thermocycling, the fracture resistance of the teeth was measured, and their esthetic appearance was assessed using Easyshade spectrophotometer and the United States Public Health Service (USPHS) visual scale. One-way ANOVA, Tukey’s post-hoc test, and paired t-test were used to analyze the data (alpha=0.05).
Results: The secondary fracture resistance was significantly lower than the primary fracture resistance in the control (P=0.000), CC (P=0.01), BSB&LB (P=0.004), BO&LO (P<0.001), and BSB&LO (P<0.001) groups. The CC group showed a significantly higher secondary fracture resistance than the BO&LO group (P=0.02). Although a more favorable esthetic appearance was observed in the BSB&LB group, no significant difference was found in color difference (∆E) among the groups. Moreover, no statistically significant difference was detected among the study groups regarding the USPHS scale (P>0.05).
Conclusion: Restoration with the CC method may improve the fracture resistance of reattached fragments in simulated CFs in maxillary incisors. However, no considerable difference was found regarding the esthetic appearance among the tested techniques.