Occlusal force and oral tactile sensibility measured in partially edentulous patients with ITI implants

Maximal occlusal force and oral tactile sensibility were recorded in (1) a group of partially edentulous patients restored with ITI implants supporting fixed prostheses or single crowns and (2) a control group consisting of fully dentate subjects with healthy natural teeth. Maximal occlusal force was measured with a miniature force transducer placed between antagonistic implant/tooth pairs in the test group and antagonistic teeth in the control group. The detection threshold of minimal pressure (ie, passive tactile sensibility) was recorded with dynamometers, and minimal perceived thickness (active tactile sensibility) was assessed using steel foils with a thickness from 100 to 10 microns. Highest maximal occlusal force was measured in fully dentate subjects on second premolars (average 450 N). A significant reduction on the first premolars (300 N) was observed. With fixed prostheses supported by implants, the average value of maximal occlusal force was distinctly lower, about 200 N for first premolars and for molars, and 300 N for second molars. The maximum force was again found on second premolars. The detection threshold of minimal pressure was significantly higher on implants than on natural teeth. The average number of wrong assessments when testing steel foils was 3.2 for antagonistic implant/tooth pairs and 2.6 for natural teeth. The comparison of test sides (with implants) and control sides (without implants) in patients of the test group did not reveal significant differences of measurements. It seems that patterns of oral function depend primarily on the state of dentition, type of prosthodontic restorations, and on psychological aspects, and secondarily on the presence of implants.