Implants inserted with low insertion torque values for intraoral welded full-arch prosthesis: 1-year follow-up.

Objectives: The aim of the present study is to evaluate the osteointegration and crestal bone remodeling after 1 year around implants for intraoral welded immediate full-arch prosthesis inserted with low insertion torque (IT) values.

Material And Methods: The study was conducted from June 2008 to September 2010. Patients were eligible for the study if they needed an immediate intraoral welded implant-supported full-arch fixed prosthesis and received three or more implants with an IT ≤ 20 Ncm and two or more implants with IT ≥ 25 and ≤ 50. For each implant, peak IT was recorded during insertion surgery; periapical x-rays were taken at the time of surgery and again after 12 months. Finally, it was recorded whether an implant was lost or removed (within 12 months from insertion surgery).

Results: Thirteen patients were included in the study; the prosthesis presented the following number of implants: nine with six implants and four with seven implants. A totand al of 82 implants were inserted: 51 implants presented an IT ≤ 20 Ncm (test group), 31 implants presented an IT ≥ 25 and ≤ 50 Ncm (control group). Each prosthesis presented at least three test implants and two control implants. The survival rate after 1 year was 98% for the test and 100% for the control group. The mean distance between the fixture-abutment junction and the bone crest was 0.1 ± 0.8 mm for test and 0.2 ± 0.5 mm for control group at implant insertion. After 12 months, it was 0.7 ± 0.9 mm for test group and 0.8 ± 0.6 mm for control group. The differences were not statistically significant.

Conclusions: Within the limitations of this study, the results suggested that rigid framework splinting can be a viable technique to improve success rate of implants with low primary stability using immediate loading protocols for full-arch prosthesis.