Mechanosensation and maximum bite force in edentulous patients rehabilitated with bimaxillary implant-supported fixed dental prostheses

Objective: The aim of this study was to compare tactile sensitivity and maximum voluntary bite force (MBF) of edentulous patients with implant-supported fixed dental prostheses (IFDP/IFDPs) to those wearing complete dentures (CG-CC) and fully dentate subjects (CG-DD). Methods: Seven edentulous subjects with IFDP/IFDPs, seven with CG-CC and seven CG-DD, matched for age and gender, participated in the pilot experiments. Three active tactile thresholds (absolute, 50% and 100%) were evaluated by means of copper foils of decreasing thickness (12 foils: 700-5 mu m). The passive thresholds were measured in six different sites per quadrant using a custom-made computer-supported strain gauge. MBF was evaluated electronically using the central-bearing point method. Results: Active tactile thresholds were different between all three groups of dental state (Kruskal-Wallis: absolute P = 0.0156; 50% P = 0.0019; 100% P = 0.0059). The active tactile sensitivity with IFDP/IFDPs was between those of the two other groups, except for the 100% threshold. The median passive tactile threshold was higher in patients with IFDP/IFDPs (5.7 N) than in CG-CC (1.7 N) and CG-DD (0.5 N) (Kruskal-Wallis P < 0.0005). MBF did not differ significantly between the dental states (ns). Conclusion: IFDP/IFDPs are a valuable treatment option for restoring edentulous patients. Limitations concerning their physiological integration into the orofacial system are mainly related to a poor passive rather than active tactile sensitivity or maximum bite force.