Narrow Diameter Implants Compared to Regular Diameter Implants Installed in the Posterior Region of the Jaws-Results from One-Year Follow Up

Purpose: The aim of this prospective clinical study was to analyze marginal bone loss around Narrow Diameter Implants (NDIs) in comparison with that of Regular Diameter Implants (RDIs) installed in the posterior region of the jaws after one year of loading with single prostheses. Material and Methods: A total of 21 patients with a mean age of 57.2 years were included in the study. The patients received one implant of each diameter in the maxilla or in the mandible. Panoramic radiographs were realized immediately after prostheses installation (T0) and one year after loading (T1). Measurements were performed from implant shoulder to the first point of bone/implant contact. The differences in marginal bone change between the groups were analyzed by Student t-test for paired samples. A level of 95% of significance was adopted. Results: A total of 42 implants were installed (21 RDIs and 21 NDIs). At the end of the follow-up period (12 months of loading), implant success and survival rates of 100% were observed. The bone loss around implants at T0 was 0.41 (± 0.45) mm for NDIs and 0.47 (± 0.60) mm for RDIs and at T1 was 1.3 (± 0.3) mm for NDIs and 1.24 (± 0.3) mm for RDIs. No statistically significant differences between the groups were found (p>0.05). Conclusion: This study demonstrated that RDIs and NDIs produced similar marginal bone alterations patterns after one year of loading, regardless the implant location, indicating that NDIs may be used in the posterior region of the jaws with single unit prostheses in selected patients.