Marginal ridge strength of restored teeth with modified Class II cavity preparations.

This study compared marginal ridge fracture resistance in two groups of teeth restored with modified Class II cavity preparations, with control groups. The results indicated that the composite resin and dental amalgam restored teeth fractured at compressive loads that were not statistically different from those of the control (unprepared, intact) teeth. The marginal ridges of the unrestored, prepared teeth were significantly weaker.