The evaluation of implant stability measured by resonance frequency analysis in different bone types

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.

The evaluation of implant stability measured by resonance frequency analysis in different bone types

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.

[Histologic and morphometric evaluation of the effects of bio-oss and cerasorb, on residual ridge preservation following tooth extraction in dog]

Following extraction of teeth the alveolar ridge resorbs and may result in inadequate bone volume for dental implant placement. The aim of this study was to make a histologic and morphometric analysis of the effect of using Bio-oss [a bovine derived xenograft] and Cerasorb [a beta tricalcium phosphate synthetic material] in preventing or reducing the alveolar bone resorption following tooth extraction in comparison with empty sockets as untreated control in a dog model. In this interventional animal study, 5 healthy adult dogs were used. The 2[nd] and 3[rd] mandibular premolars were extracted after reflecting a surgical flap. Following random allocation, the available sockets either served as the untreated control [n=13] or received either Bio-oss [n=10] or Cerasorb [n=10] as test groups. An alginate impression was taken before the application of materials to fabricate a stone cast to serve as an index to make morphometric measurements. The healing events were uncomplicated and six months after the surgical procedures, the dogs were sacrificed and after removing the soft tissues, another impression was taken from the mandibular hard tissues and the tissue blocks were prepared for histologic examination. Morphometric maesurments aimed to measure the changes in vertical dimentions of the buccal and lingual bony plates as well as the horizontal reduction of the ridge at the crest. The data were analyzed by ANOVA and Kruskal-Wallis test. The histologic evaluation included the examination of the quality of the harvested hone as well as the inspection for the presence of remnants of unresorbed biomaterials. The mean changes of buccal and lingual crests and mean ridge reduction were not significantly different between control and cases groups. Histologic examination revealed that in all three groups, the cortical bony plates were thinner and of lower density at the buccal side compared to the lingual side. No trace of inflammatory cell infiltration was observed in any groups. In general, the histologic appearance of the 3 types of specimens resembled to normal lamellar bone. The results of this study showed that the vertical and horizontal resorbion of alveolar ridge following the extraction were minimal at three groups even at the untreated control sites