In vivo vertical forces on implants.

Vertical forces applied to dental implants during oral functions have not been quantified precisely. The key problem has been the lack of suitable measuring devices. This article introduces a new technique for placing a transducer directly in the implant without any increase in vertical dimension. Results were compared to loads applied to teeth. Implants in the molar position that were fixed to a premolar with a prosthesis withstood maximum vertical forces of 60 to 120 N during chewing. Single molars and premolars carried maximum vertical forces of 120 to 150 N. Clenching in centric occlusion caused a load level of approximately 50 N for both natural and artificial abutments. Occlusal prematurities on the implant restoration that were less than 200 microns in height showed no significant increase of the implant load level.