ABSTRACT

INTRODUCTION The considerations for replacement of single molars are not primarily aesthetic as in the preceding section on anterior teeth, but the mechanical considerations are far more important. It is not generally recommended to replace a molar with a single implant of 4 mm diameter or less because of the potentially large cantilever forces that it could be subjected to (Fig. 4.1), resulting in biomechanical failure (abutment screw loosening/fracture or implant fracture-see chap. 16). The basic alternatives are therefore, placement of two standard implants or a single wide-diameter implant. The space requirements and potential costs are quite different.