Resonance Frequency Analysis of Implant Clinical Stability on Astra tech and ITI Implant Systems

Resonance frequency analysis (FRA) offers a clinical noninvasive measurement of stability and osseointegration of implants. The RFA values are represented by a quantitative unit called the Implant stability quotient (ISQ) on a scale from1 to 100. The objective of the present study was to measure the stability of Astra tech and ITI dental implants during the healing period and determine the factors that affect the ISQ. In this clinical trial study approved by ethical committee of Mashhad University of Medical Sciences 14 healthy subjects candidate for dental implants were randomly divided into two groups. Group one received 15 Astra tech and group two received 15 ITI dental implants. ISQ was used for direct measurement of implant stability on the day of implant placement and first third and sixth month after implant placement. Data were analyzed by student-t test and ANOVA and Spearman Rank Correlation Test through SPSS 11.5 with 95% confidence interval. The mean ISQ of Astra Tech implant at third and sixth month were significantly greater than ITI implant (P=0.001 and P=0.018 respectively). Statistical analysis showed higher ISQ values for mandible than maxilla (P=0.001). Bone quality significantly affected ISQ value and implant diameter was significantly correlated to implant stability (P=0.02). Our results showed that Astra tech implants had significantly greater ISQs in third and sixth month than ITI implants. Furthermore bone quality implant surface texture (implant system) and diameter can affect implant stability and time of loading.