Effect of different attachments on marginal bone loss around mini implants supporting mandibular over dentures

Abstract

Ten completely edentulous patients were selected from the outpatient clinic, prosthodontic department, faculty of dentistry, ain shams university to participate in this study. All the selected patients were rehabilitated by mucosa supported maxillary complete dentures and mini- implant retained mandibular overdentures. Patients were randomly divided into two equal groups Group I and group II. Cone beam computerized tomography (CBCT) was made for all patients to assess the bone quality of the mandibular alveolar ridge, to locate the position of mental foramina, and to evaluate available bone height at the interforaminal region. Four mini dental implants* (MDI) one piece, screw- type 2.55 mm in diameter and 10 mm in length were used for each patient. The implants used for patients of group I were with square heads, while the implants used for patients of group II were with ball heads. For group I patients, the lower overdentures were retained to square head splinted mini implants through clip bar attachments. while for group II patients, the lower overdentures were retained to the ball head separate mini implants by O-rings in metal housings. Recall appointments were scheduled for the patients one and two weeks after implant loading for evaluation of the prosthesis and to perform any needed adjustment. Follow up visits were scheduled six and twelve months after denture insertion for clinical and radiographic evaluation of the implants.