OVERDENTURES SUPPORTED BY 2 IMZ IMPLANTS IN THE LOWER JAW - A RETROSPECTIVE STUDY OF PERI-IMPLANT TISSUES

Between 1987 and 1990, 57 edentulous patients were treated with overde ntures supported by 2 endosseous IMZ implants connected by a bar in th e lower jaw. The condition of the peri-implant tissue was evaluated fo r a loading period ranging from 12 to 57 months (mean 30 months and me dian 24 months). The evaluation parameters included Plaque Index, Blee ding Index, Gingiva Index, pocket depth, dysesthesia of chin or lip, p eri-implant bone loss and loss of implants. During the healing phase p rior to the construction of an overdenture, 3 implants were lost. Afte r a healing period of 6 months, these implants were successfully repla ced. During the follow-up period, a Plaque Index less than or equal to 1 was observed in 45 patients and an abundance of plaque and calculus was observed in 1 patient. Heavy or profuse bleeding and severe gingi val inflammation was observed in 3 patients. The mean pocket depth was 3.6 +/- 1.7 mm. None of the patients experienced lip or chin dysesthe sia. Marginal bone loss was observed around 30 (26%) implants. From th is study it is concluded that, once proper osseointegration is obtaine d, 2 IMZ implants connected with a bar in the lower jaw supply a prope r base for the support of an overdenture; the condition of the peri-im plant tissues is steady and independent of the follow-up time.