Alveolar ridge split technique and immediate implant placement in atrophic maxilla. Case series

Abstract

Background: Alveolar ridge split technique (ARST) is a surgical procedure performed for horizontal ridge augmentation in cases of narrow crestal ridges. It is a biologically oriented technique, taking advantage of the osteogenic and osteoconductive dynamic of the native bone. Recently, the utilization of devices such as thin diamond disks or piezoelectric cutting devices has enhanced ARST success rate, reduced surgical time and patient's morbidity, regardless of bone quality. Aim/Hypothesis: The purpose of this poster is to present and discuss our experience in a series of clinical cases where ARST was performed for horizontal bone augmentation with simultaneous implant placement, using classical or piezoelectric-assisted surgical procedures. Materials and Methods: ARST was performed in 6 patients with 10 sites of horizontal defects. Under local anesthesia, a crestal incision was performed and a full thickness mucoperiosteal flap was reflected. Initial osteotomy was done using the classical technique in 6 cases (diamond disk, rotary burs), while a piezoelectric device was used to the remaining 4 cases. Osteotomes and chisels with gradually increasing dimensions were used to expand the alveolar ridge to facilitate the immediate placement of 18 implants, approximately 2 mm subcrestally in order to prevent marginal bone loss. The remaining space between bony plates was filled with allograft or xenograft and covered with collagen membrane in 9 cases, while in one case no bone graft or membrane were used. Primary closure without tension was achieved with periosteum releasing incisions of the buccal flap. Post-operative instructions included administration of antibiotic and analgesic, chlorhexidine solution, smoke cessation and thorough oral hygiene. Results: Sutures were removed 10 days postoperatively. Follow up was uneventful for 5 out of 6 patients. One patient did not comply with the postoperative instructions, applying poor oral hygiene and continuing smoking as before which resulted in exposure of the collagen-membrane the second week, leading to secondary wound closure compromising the augmentation. A new CBCT was performed 4 months following the split which revealed successful bone augmentation and implant osseointegration without any significant bone loss around the implants. Oral rehabilitation with either fixed or removable prosthetics was accomplished and the patients remain under systematic review. Conclusions and Clinical Implications: ARST is a predictable and reliable procedure characterized by its low invasiveness and morbidity. The major advantage is the simultaneous bone augmentation- implant placement, which provides reduced treatment time and cost. Piezoelectric devices make the split technique easier and safer, decreasing the risk of complications in the treatment of extremely atrophic crests. ARST's success and efficacy depends greatly on patient selection in order for the basic anatomical criteria to be fulfilled. Keywords: ridge splitting, horizontal bone augmentation, piezoelectric device