Implants and Sinus-Inlay Graft in a 1-Stage Procedure in Severely Atrophied Maxillae: Prosthodontic Aspects in a 3-year Follow-up Study
Jan-Ivan Smedberg, DDS, PhD, Björn Johansson, DDS, Jan Ekenbäck, DDS, Karin Wannfors, DDS, PhD
The aim of this 3-year prospective study was to evaluate the prosthetic treatment in 2 groups of maxillary edentulous patients with similar age and gender distribution: a study group of 39 patients treated with intra-sinus block bone grafts and implants in a 1-stage procedure, and a control (reference) group of 37 patients treated with implants and no grafting. In the study group, bone volumes were regarded as insufficient for implant treatment unless a bone grafting procedure was performed (posterior alveolar bone height was less than 5 mm). Self-tapping Nobel Biocare implants were used in both groups of patients. In the study group, 35 fixed partial dentures and 4 overdentures were placed, and in the control group 34 fixed partial dentures and 3 overdentures were placed. All patients were followed for at least 3 years. The 3-year follow-up examination included examination of a number of clinical parameters as well as the type of abutment and evaluation of stability of prosthesis retention screws and abutment screws. During the follow-up period, 2 patients were lost from the study group and 4 patients from the control group, giving a total of 70 patients available for examination after 3 years (8% dropout rate). Both the amount of plaque and gingival bleeding were significantly lower in the study group than in the control group. The presence of attached gingiva was 25% in the study group and 35% in the control group. The number of angulated abutments was significantly higher in the study group than in the control group. There was no significant difference in the number of prosthetic complications in the 2 groups of patients. Neither was there any significant difference in prosthesis screw or abutment screw stability between the 2 groups. The type of abutment did not significantly influence the stability of prosthesis retention screws or abutment screws in either of the groups. However, prosthesis screw stability was significantly greater than abutment screw stability in both groups of patients. It can be concluded that the prosthetic outcome was similar in the 2 groups of patients, regardless of whether or not a bone grafting procedure was used.