Impact of Dental Implant Diameter on Peri-Implant Bone Levels: A Retrospective Clinical Study of Branemark Implants

Objectives: There have been conflicting studies that increase in the diameter of dental implants either results in greater or less crestal bone loss. There has been anecdotal evidence of greater bone loss specifically with the Branemark wide platform implants compared to the other diameter sizes. However there is a paucity of literature elucidating the effect of implant diameter with the system of implants. The hypothesis is that there will be a positive correlation with implant diameter and bone loss. The aim of this study is to evaluate the effect of implant diameter on peri-implant bone levels. A cross-sectional representation of implant patients will be collected, the analysis of which may benefit providers and the dental community in providing the best dental care to patients.;Methods: This study is a retrospective Chart Review. Patient population includes consecutive patients treated for dental implant placement and restoration at the Departments of Dental Specialties and Oral and Maxillofacial Surgery at Mayo Clinic, Rochester, Minnesota, USA. Single implants with single restorations were evaluated. Data was collected from the period of April 2008 to December 2010. The collection of data was performed by one investigator (PL). Measurements and calculation of data was acquired through standard methods on panoramic, periapical, and/or bitewing radiographs. This study evaluated a total of 101 implants in 91 patients. Implant were from the Nobel BioCare Branemark MkIII TiUnite implant system. 47 patients with 5.0-mm, 40 patients with 4.0-mm, and 14 patients with 3.75-mm diameter implants respectively. Data collected from digital radiographs using QREADS to measure crestal bone loss on mesial and distal surfaces.;Results: There were 101 implants placed between April of 2008 and December of 2010 among 91 distinct patients eligible for study. The mean difference in mesial bone level, calculated as follow-up minus baseline, was 0.8 (median 0.6; range -1.2 to 6.1); the mean difference in distal bone level was 0.8 (median 0.7; range -1.5 to 4.7). When results were pooled for non-wide platform implant of the 3.75 mm and 4.0 mm diameter groups to the wide platform 5.0 mm diameter group, the differences in mesial and distal bone levels were statistically significantly different from zero (p<0.001 for both; Wilcoxon signed rank tests). The Spearman rank correlation coefficients for the associations of age at implant with differences in mesial and distal bone levels were -0.01 (p=0.91) and 0.03 (p=0.78), respectively. There was evidence that implants among diabetic patients had smaller differences in mesial bone levels compared with implants among non-diabetics (median differences of 0.2 and 0.8, respectively; p=0.049). Wide-platform implants 5.0 mm in size had larger differences in both mesial (p=0.046) and distal (p=0.029) bone levels compared with 3.75 or 4.00 mm implants.;Conclusion: In this study there was a positive correlation in increase implant diameter with increase crestal bone loss in the Nobel BioCare Branemark MkIII TiUnite implant system. One must keep in mind this was a small patient pool and further studies will be necessary to clarify the relationship between implant diameter and bone loss. Caution should be taken in translating these results to implant failure, which was not addressed in the present study. The significance to clinical practice will need to be investigated further. Wider implants may not always be the best implant solution and clinical judgment is essential for implant selection for the individual patient.