Probing depth at implants and teeth. An experimental study in the dog.
The aim of the present investigation was to assess the resistance offered by the gingiva at teeth and the peri-implant mucosa at osseointegrated titanium implants to mechanical probing. 5 beagle dogs were used in the experiment. The 2nd and 3rd premolars and the 1st molars of the right and left mandibular dentition were extracted. 2 titanium implants were installed in the edentulous right and left premolar- and molar-regions. Abutment connection was performed 3 months later. The remaining premolar in the left jaw (P4) was exposed to "experimental periodontitis" during a 4-month period and, thus, the 4th premolar in the right jaw (4P) was representing healthy periodontium. The inflamed soft tissues at P4 were treated using a flap procedure. Following 2 weeks of healing, the main experiment was started, i.e., day 0. During the subsequent 360 days, the teeth and abutment parts of the implants were regularly exposed to plaque control (3 x/week). Radiographs of 4P-, P4- and the implant-regions were obtained on days 0 and 360. Mobility measurements were performed on days 0 and 360. Biopsies of the experimental teeth and the implants were sampled at the end of the study. The results of the present experiment demonstrated that differences in terms of tissue composition, organization and attachment between the gingiva and the root surface on one hand and between the peri-implant mucosa and the implant surface on the other, make the conditions for probing depth measurements at teeth and implants different.