OBJECTIVES: Bone density seems to be an important factor affecting implant stability. The relationship between bone density and primary and secondary stability remains under debate. The aim of this study was to compare primary and secondary stability measured by resonance frequency analysis (RFA) between different bone types and to compare implant stability at different time points during 3 months of follow-up. MATERIALS AND METHODS: Our study included 65 implants (BioHorizons Implant Systems) with 3.8 or 4.6 mm diameter and 9 or 10.5 mm length in 59 patients. Bone quality was assessed by Lekholm-Zarb classification. After implant insertion, stability was measured by an Osstell device using RFA at three follow-up visits (immediately, 1 month, and 3 months after implant insertion). ANOVA test was used to compare primary and secondary stability between different bone types and between the three time points for each density type. RESULTS: There were 9 patients in type I, 18 patients in type II, 20 patients in type III, and 12 patients in type IV. Three implants failed, 1 in type I and 2 in type IV. Stability values decreased in the first month but increased during the following two months in all bone types. Statistical analysis showed no significant difference between RFA values of different bone types at each follow-up or between stability values of each bone type at different time points. CONCLUSION According to our results, implant stability was not affected by bone density. It is difficult to reach a certain conclusion about the effect of bone density on implant stability as stability is affected by numerous factors.

OBJECTIVES: Bone density seems to be an important factor affecting implant stability. The relationship between bone density and primary and secondary stability remains under debate. The aim of this study was to compare primary and secondary stability measured by resonance frequency analysis (RFA) between different bone types and to compare implant stability at different time points during 3 months of follow-up. MATERIALS AND METHODS: Our study included 65 implants (BioHorizons Implant Systems) with 3.8 or 4.6 mm diameter and 9 or 10.5 mm length in 59 patients. Bone quality was assessed by Lekholm-Zarb classification. After implant insertion, stability was measured by an Osstell device using RFA at three follow-up visits (immediately, 1 month, and 3 months after implant insertion). ANOVA test was used to compare primary and secondary stability between different bone types and between the three time points for each density type. RESULTS: There were 9 patients in type I, 18 patients in type II, 20 patients in type III, and 12 patients in type IV. Three implants failed, 1 in type I and 2 in type IV. Stability values decreased in the first month but increased during the following two months in all bone types. Statistical analysis showed no significant difference between RFA values of different bone types at each follow-up or between stability values of each bone type at different time points. CONCLUSION: According to our results, implant stability was not affected by bone density. It is difficult to reach a certain conclusion about the effect of bone density on implant stability as stability is affected by numerous factors.
Bone Density ; Classification ; Dental Implants ; Follow-Up Studies ; Humans

Objectives: The stability of crestal bone has been reported as a major factor in the success of dental implants. Implants can be placed in an equicrestal (crestal) or subcrestal position. The aim of this study was to evaluate the effect of implant depth placement on marginal bone loss. Materials and Methods: The study was created in a split-mouth design. Immediately after implant surgery, digital parallel radiographs were prepared and levels of bone were measured where marginal bone loss and bone level changes occurred. These measurements were repeated at 3-month and 6-month follow-up periods. Results: In this interventional study, 49 implants were evaluated in 18 patients. Primary bone height was not significant between the intervention and control groups in both mesial and distal aspects at 3 months and 6 months from the baseline. The mean marginal bone loss on the mesial side was 1.03 mm in the subcrestal group and 0.83 mm in the crestal group. In addition, mean marginal bone loss on the distal side was 0.88 mm and 0.81 mm in the subcrestal and crestal groups, respectively. Marginal bone loss was not significantly different between sexes, the maxilla or mandible, and in the anterior or posterior regions as well as between different lengths and diameters of implants. Conclusion Based on the results of this study, there was no significant difference in terms of marginal bone loss between crestal and subcrestal implants.