Tactile sensibility of single-tooth implants and natural teeth

Aim: The purpose of this randomized split-mouth clinical trial was to determine the active tactile sensibility between singe-tooth implants and opposing natural teeth and to compare it with the tactile sensibility of pairs of natural teeth on the contralateral side in the same mouth (intraindividual comparison). Material and Methods: The hypothesis was that the active tactile sensibilities of the implant side and control side are equivalent. Sixty two subjects (n=36 from Bonn, n=26 from Bern) with single-tooth implants (22 anterior and 40 posterior dental implants) were asked to bite on narrow copper foil strips varying in thickness (5-200 mu m) and to decide whether or not they were able to identify a foreign body between their teeth. Active tactile sensibility was defined as the 50% threshold of correct answers estimated by means of the Weibull distribution. Results: The results obtained for the interocclusal perception sensibility differed between subjects far more than they differed between natural teeth and implants in the same individual [implant/natural tooth: 16.7 +/- 11.3 mu m (0.6-53.1 mu m); natural tooth/natural tooth: 14.3 +/- 10.6 mu m (0.5-68.2 mu m)]. The intraindividual differences only amounted to a mean value of 2.4 +/- 9.4 mu m (-15.1 to 27.5 mu m). The result of our statistical calculations showed that the active tactile sensibility of single-tooth implants, both in the anterior and posterior region of the mouth, in combination with a natural opposing tooth is similar to that of pairs of opposing natural teeth (double t-test, equivalence margin: +/- 8 mu m, P < 0.001, power > 80%). Hence, the implants could be integrated in the stomatognathic control circuit.