Int J Oral Maxillofac Implants 22 (2007), No. 2 15. Mar. 2007
Int J Oral Maxillofac Implants 22 (2007), No. 2 (15.03.2007)
Page 226-234, PubMed:17465347
Clinical Evaluation of a Prospective Multicenter Study on 1-piece Implants. Part 1: Marginal Bone Level Evaluation After 1 Year of Follow-up
Finne, Kaj / Rompen, Eric / Toljanic, Joseph A.
Purpose: The aim of the present investigation was to evaluate the marginal bone level after 1 year of follow-up of 1-piece implants after immediate provisional restoration fabrication.
Materials and Methods: Patients received NobelDirect and NobelPerfect 1-piece implants (Nobel Biocare, Göteborg, Sweden) that were immediately restored and placed into function as part of a 3-year, multicenter investigation. Life table analysis was used for evaluation of implant cumulative survival rates. The Student t test (for dichotomous variables) and Pearson correlation (for continuous and ordered categorical variables) were used to estimate the influence of separate parameters on marginal bone.
Results: Eighty-seven patients received 152 NobelDirect or NobelPerfect 1-piece implants. Of these, 81 patients returned for the 1-year follow-up and 21 for the 2-year follow-up. Three implants were lost, resulting in a cumulative survival rate of 97.9% after up to 2 years. The average marginal bone level at implant placement was 0.33 mm (SD 1.20, n = 141) superior to the reference point (lower edge of the implant collar). Marginal bone level was -0.77 mm (SD 1.33, n = 138) at 6 months and -0.98 mm (SD 1.38, n = 123) at 1 year. Average bone level at the 2-year follow-up was 0.17 mm (SD 1.20, n = 26). After 1 year of loading, bone level in the maxilla was more apical compared to that in the mandible (P = .05), and a positive correlation was found between bone level at placement and bone level at 12 months (P = .008). Shallow implant positioning resulted in less marginal bone remodeling compared to deep implant positioning.
Conclusion: On the basis of this prospective multicenter study, stable marginal bone level and soft tissue support the hypothesis that the 1-piece implant has the capacity to preserve both hard and soft tissue.
Keywords: bone level, immediate function, 1-piece dental implants, radiologic evaluation