[The occlusal force distribution on the dental arch restored with implants in uni-lateral molars missing]

The object of this study was to discuss the occlusal force distribution on the dental arch before and after wearing implant-supported prostheses. The occlusal force was measured on four patients missing uni-lateral molars restored with 14 dental implants. The occlusal force distribution was represented as the occlusal force bearing rate (B.R.) which is the percentage of occlusal force on each portion to the total occlusal force. B.R. of the implant portion, of the non-implant side molar portion and of the anterior portion were calculated on four patients. B.R. of the premolar implant portion and of the molar implant portion were calculated on two patients. The pressure sensitive sheets and the image scanner (Dental Prescale 50H type R and Occluzer FPD 703, Fuji Photo Film Co.) were used in this study. The results were as follows: 1. The corresponding occlusal force was also born with the implant portion. Therefore, the total occlusal force increased, and the occlusal force distribution was extended to the same degree as the natural dentition after wearing the implant-supported prostheses. 2. The occlusal force and B.R. on the molar implant portion were considerably large regardless of wearing premolar implants. 3. The occlusal force and B.R. on the most distal implant in any molar portion were almost constant. These results suggested that the implant restoration should be useful for recovering occlusal functions, and that the most distal implant on the dental arch should have the sufficient bearing potential.