Objectives: The objective of this 3-year split-mouth randomized controlled clinical study was to compare narrow-diameter implants (NDIs) to regular-diameter implants (RDIs) in the posterior region of the jaws (premolars and molars) in regards to (i) the marginal bone level (MBL) and (ii) implant and prosthesis survival and success rates. Material and Methods:A total of 22 patients were included in the study. Each patient received at least one implant of each diameter (Ø3.3 and Ø4.1 mm), placed either in the maxilla or mandible to support single crowns. A total 44 implants (22 NDIs and 22 RDIs) were placed and included in the study. Twenty-one implants were placed in the premolar, whereas 23 were placed in molar areas. Radiographic evaluations to access the MBL were performed immediately after implant placement, 1 and 3 years after implant loading. Peri-implant clinical variables including probing pocket depth (PPD) and bleeding on probing (BoP) were obtained after crown delivery, 1 and 3 years after loading. Furthermore, the survival and success rates of the implants and prosthesis were also evaluated.Results: Twenty patients were able to complete the study. There was no statistically significant difference regarding MBL between groups at implant placement (p = .084), 1-year (p = .794) and 3-year (p = .598) time intervals. The mean peri-implant bone loss at 3-year follow-up was −0.58 ± 0.39 mm (95% CI: −0.751 to −0.409) and −0.53 ± 0.46 mm (95% CI: −0.731 to −0.329) for NDIs and RDIs, respectively. BoP was present at 15% and 10% of NDIs and RDIs, respectively, at 3-year follow-up. PPD >5 mm was observed in 5% and 0% of the implants of NDIs and RDIs, respectively, at 3-year follow-up. At the 3-year examination, the implant success rates were in the NDIs and RDIs sites, respectively, 95% and 100%. The corresponding values for prosthesis success rates were 90% for NDIs and 95% for RDIs. Conclusion:The present study demonstrated that NDIs placed to support single crowns in the posterior region did not differ to RDIs in regards to MBL, implant survival, and success rates. K E Y W O R D Sbone resorption, dental implants, narrow diameter, radiography

Narrow diameter implants installed immediately after split-crest procedure may successfully support prosthetic rehabilitations after long-time intervals.

The present study suggests that, in a short-term follow-up, narrow diameter implants made of either titanium-zirconium alloy or commercially pure titanium may be used to support single crowns in the posterior portions of the jaws.

Immediate implant placement of mandibular molars proved to be a viable surgical treatment given the high success rate up to 8 years after implantation.

TiZr and cpTi NDIs presented similar outcomes after 1 year in function in the molar region of the mandible. The results suggest that TiZr and cpTi NDIs may be equally used to support single crowns in the posterior area of the mouth. However, further studies with longer follow-up periods are necessary to confirm these findings.

No abstract

No abstract

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.