HISTOLOGIC PROBE PENETRATION IN HEALTHY AND INFLAMED PERI-IMPLANT TISSUES

Periodontal probing is commonly used for assessing both the status of gingival health and the connective tissue attachment level around teet h. The role of probing around endosseous implants still remains unclea r. The purpose of this study was to determine the histological level o f probe penetration in healthy and inflamed mucosal tissues around imp lants. Five beagle dogs were used and a total of 30 one-stage, Titaniu m Plasma Spary (TPS)-coated implants of the ITI type were placed in th e mandibles. After the healing period with meticulous oral hygiene, th e dogs were divided into 3 groups: 1) clinical healthy mucosal tissues ; 2) experimental mucositis (3 dogs); and 3) experimental ligature-ind uced peri-implantitis (2 dogs). Four months after implant placement, r espectively 6 months in the third group, 60 probes were placed with a standardized force of 0.2 N and fixed at the mesial and distal aspects of the implants. Probing depth, clinical attachment level (CAL), Plaq ue Index (P1I) and Gingival Index (GI) were assessed throughout the st udy. Tissue sections were obtained for histometrical analysis. In the healthy group, the mean PII was 0.47, the GI 0.06 and the clinical pro bing depth (CPD) 2.12 mm. In the mucositis group the PII was 1.61, the GI 1.61 and the CPD 1.87 mm. In the peri-implantitis group the P1I wa s 1.96, the GI 2.05 and the CPD 3.73 mm. The histologic results show t hat the probes were able to identify the connective tissue adhesion le vel in the healthy group with a mean error of -0.05 mm (mean histologi c probing depth (HPD): 1.75 mm) and, in the mucositis group, with -0.0 2 mm (mean HPD: 1.62 mm). Probe penetration increased with the degree of inflammation and in the peri-implantitis group the probe exceeded t he connective tissue level by a mean 0.52 mm (mean HPD: 3.8 mm). There fore, probing around implants represents a good technique for assessin g the status of peri-implant mucosal health or disease.