Purpose: The aim of this study was to examine the correlation of the subjective and the objective evaluation of edentulous
ridge bone quality, and to evaluate the change of the dental implant stability in each bone density group for early healing
period after implant installation.
Methods: Sixty-seven implants(Osstem implant
®
, Seoul, Korea) were included in this study. We evaluated the bone density
by 2 methods. The one was the subjective method which was determined by practitioner’s tactile sense, the other was the
objective bone type was based on Hounsfield units. The implant stability in each bone type group was assessed by resonance
frequency analyzer(Osstell mentor
). Data were analyzed for the change of the implant stability, and they were compared to
verify the difference of groups at the time of installation, 2, 6, 10, 14 weeks postoperatively. Spearman’s correlation was used
to demonstrate the correlation between the subjective and the objective evaluation of the bone density, and analysis of
variance(ANOVA) was used to analyze the differences of implant stability at each time point.
Results: There was no close relation between the subjective and the objective evaluation of the bone density(r=0.57). In the
subjective groups, there was statistically significant difference between the type 1 and 3 at 10 weeks and between the type
2 and 3 at 14 weeks. In the objective groups, there was no statistically significant difference between the D 1, 2, 3, 4, and
5 group with regard to RFA from baseline to 14 weeks(P>0.1).
Conclusions: The implant stability increased over time during the study, and it was improved with bone density
proportionally after 2weeks postoperatively. It is recommended that the decision of bone density is base on Hounsfield unit
for implant loading time. (J Korean Acad Periodontol 2009;39:185-192)