Osseintegration following treatment of peri-implantitis and replacement ofimplant components - An experimental study in the dog

Aim: The aim of the present experiment was to study if the quality of the t itanium surface is a decisive factor for osseointegration and re-osseointeg ration. Material and Methods: 2 Labrador dogs were used. The mandibular Ist molars and all premolars were removed bilaterally. 3 months later, 1 standard fixt ure and 3, 2-part "test fixtures" were installed in each side of the mandib le. The text fixtures consisted of 1 6-mm long apical and 1 4-mm long coron al part connected with an internal screw. After 4 months, abutment connecti on was performed. 5 months later, a period of experimental peri-implantitis was initiated during which about 50% of the supporting bone tissue was los t. The dogs were later subjected to a treatment that included (i) systemic administration of antibiotics and (ii) surgical debridement of all implant sites. The abutments and the coronal parts of the text fixtures were remove d. All parts of the exposed portion of the standard fixtures, the connectin g screw and the apical part of the test fixtures were meticulously cleaned by mechanical means. A pristine, coronal fixture part was via the connectin g screw attached to the apical fixture part of each text fixture. All fixtu res were submerged. 2 weeks later, a fluorochrome was injected intravenousl y. After 4 months, biopsies of the implant sites were dissected and prepare d for ground sectioning and analysis. Results: It was demonstrated that re-osseointegration failed to occur to im plant surfaces (standard) exposed to bacterial contamination, but did consi stently occur at sites where a pristine implant component was placed in the bone defect following surgical debridement. Conclusion: The above findings seem to imply that the quality of the titani um surface is of decisive importance for both osseointegration and re-osseo integration.