Implant Stability by Resonance Frequency Analysis at Abutment Level

Objective: Ability to accurately measure implant stability will improve capacity to assess implant prognosis. Past studies have discussed how to measure implant stability, however, there has been a great controversy over which technique is accurate and reproducible. Resonance Frequency Analysis (RFA) has shown promising results in terms of Implant Stability Quotient (ISQ). Until recently, this technology has not been available after abutment connection. We have previously reported that the ISQ measurements at abutment level can be measured, and these were significantly lower than at fixture level (p≤0.05). The aim of this study is to determine if there is a correlation between abutment height and ISQ value. 

Method:  Nineteen abutments (NobelBiocare, RP Multi-unit), were identified. ISQ bucco-lingual (BL) and mesio-distal (MD) measurements were obtained at abutment level and recorded at one-year post placement. The sample was divided into three groups based on abutment height: Group 1 = 1mm (n=7); Group 2 = 2mm (n=7) Group 3= ≥3 mm (n=5). T-test and ANOVA were performed to compare the data set. 

Result:  Mean ISQ on all abutments in MD direction was 78.63 ± 8.96 and BL was 51.95 ± 10.75. The mean between MD and BL was significantly different (p≤0.05). Group 1 and Group 3, and Group 2 and Group 3 were significantly different in both MD and BL directions (p≤0.05), while the difference between Group 1 and Group 2 in both directions was not significant (p>0.05). ANOVA was performed to compare the three groups and a significant difference was found in ISQ values in MD among the groups (p≤0.05), but no significant difference in BL (p>0.05). 

Conclusion:  The ISQ measurements were significantly lower in BL direction compared to MD direction. There is a significant difference in ISQ values at abutment level among different abutment heights especially in those of 3mm or greater.