RESUMEN
Aim: The aim of this study was to evaluate the in vitro fracture resistance of teeth restored with bonded ceramic inlay and direct composite resin restoration in comparison to the normal tooth. Materials and Methods: This study evaluated the fracture strength of the teeth restored with bonded ceramic inlay and direct composite resin restoration in comparison to the normal teeth. Thirty intact human maxillary first premolars were assigned to three groups: Group 1 - comprising sound/unprepared teeth (control). Group 2 - comprising of Class-II direct composite resin restored teeth and Group 3 - comprising Class-II ceramic inlay restored teeth. Cavities were prepared with occlusal width of 1/3 intercuspal distance and 2 mm deep pulpally. Group 2 teeth were restored with hybrid composite resin (Z350 3M ESPE, USA) and group 3 teeth were restored with Vitadur Alpha alumina (Ivoclare Vivadent, Liechtenstein, Europe). Ceramic inlay was bonded with adhesive cement (rely X resin cement of 3MESPE, USA). The specimens were subjected to a compressive load until they fractured. Data were analyzed statistically by unpaired Student's t test. Results: The fracture resistant strength, expressed as kilonewton (KN), was group 1 - 1.51 KN, group 2 - 1.25 KN, and group 3 - 1.58 KN. Statistically, group III had highest fracture resistance followed by group I, while group II had the lowest average fracture resistance. Conclusion: The fracture resistant strength of teeth restored with ceramic inlay was comparable to that of the normal intact teeth or slightly higher, while teeth restored with direct composite resin restoration showed less fracture resistant strength than that of the normal teeth.