Fracture Resistance Of Molars With Different Direct Cuspal Coverage Restorations

Objective: The purpose of this study was to compare the fracture resistance of four different restorations. Method: Thirty-two extracted human upper molar teeth of similar size and free of caries were used. These were randomly divided into four groups of eight specimens each. Teeth in Group I were restored using a hybrid composite resin (Filtek Z250, 3M ESPE, USA) with polyethylene fiber (Ribbond THM, USA). In Group II, an amalgam with self-threading pins was used. Teeth in Group III were restored using a hybrid composite resin with a self etch adhesive (G bond, Japan). The final restoration used amalgam and a meta adhesive system (Panavia F2.0, Kuraray, Japan) (Group IV). Each specimen was loaded in compression at a 90o angle in a universal testing machine (Instron, Corporation, USA) with a cross head spread of 0.5 mm/min. Data were analyzed using one-way ANOVA and the Duncan test for fracture resistance. Result: Group IV exhibited the lowest fracture resistance (p<0.05). Although group III exhibited the highest resistance, there was no statistically significant difference among group I, II and III (p>0.05). Conclusion: The results showed that a bonded composite restoration should be first choice for cuspal replacement.