Soft tissue exposure of endosseous implants between stage I and stage II surgery as a potential indicator of early crestal bone loss

Implants are well accepted as a means of dental rehabilitation. While integ ration success rates are high, crestal bone loss can occur, and it may not become apparent until stage II surgery and implant uncovering. The purpose of this study was to quantify the relationship between exposure of implants through the oral mucosa between stage I and stage II implant surgery and e arly changes in crestal bone height. Bone levels were measured during place ment of 275 implants in the maxillae of 50 subjects. Repeated bone height m easurements were obtained at implant uncovering. Fourteen implants in 7 pat ients were exposed to the oral cavity through the mucosa at stage II surger y. Patients with 1 or more exposed sites demonstrated a likelihood of bone loss 3.9 times greater than patients with nonexposed sites (Fisher exact te st, P = .0003). These results suggest that exposure of an implant between s tage I and stage II implant surgery might serve as a potential indicator of the occurrence of early bone loss.