Ridge expansion alone or in combination with guided bone regeneration to facilitate implant placement in narrow alveolar ridges: a retrospective study

ObjectiveTo evaluate the long-term outcomes of ridge expansion technique in dealing with horizontal bony insufficiency of alveolar ridges for implant placement. Materials and methodsDuring the period 2004-2009, 168 patients with width insufficiency of alveolar ridges were treated using the ridge expansion technique to obtain an improved bony base for implant placement. Depending on the severity of width insufficiency, the surgical procedures were classified into two groups: ridge expansion alone (Group 1) and ridge expansion in combination with guided bone regeneration (Group 2). After 4-6months of unloaded healing, the implants were restored. The patients were followed up until 2013 with clinical and radiographic examinations. ResultsAmong the 168 patients, 11 patients underwent a fracture of labial/buccal bony plate during surgery, which was corrected by changing the procedure into bone grafting, yielding a surgical failure rate of 6.5%. In the remaining 157 patients successfully treated by ridge expansion alone or in combination with GBR, 226 implants were simultaneously placed as planned. No implant failed over 2.8years (6months to 8years) of follow-up, yielding a cumulative implant survival rate of 100% in each group. Six implants in Group 1 and 4 implants in Group 2, although osseointegrated and in function, did not fulfill success criteria: Cumulative implants' success rates were 93.2% in Group 1 and 95.6% in Group 2. The mean marginal bone losses during the first year in Group 1 and Group 2 were 0.69 and 0.43mm, respectively, followed by an annual loss of similar to 0.06 and 0.07mm, respectively, in the following years. No clinical parameter was abnormal. Twenty-two (10.4%) implants were exposed to peri-implant mucositis, whereas 19 (11.0%) implant-supported restorations were involved in prosthetic complications. ConclusionsThe preliminary results of this retrospective study indicate that ridge expansion alone or in combination with GBR can be considered an effective and safe procedure for treatment of width insufficiency of alveolar ridges on the purpose of implant application.