A comparison of implant stability between implant placed without bone graft versus with bone graft using GBR technique : a resonance frequency analysis

Abstract

Objective : To compare the implant stability using the insertion torque (IT) and implant stability quotient (ISQ) values over the 12 weeks period between implant placement in bone without bone graft (control group) and with bone graft using the guided bone regeneration (GBR) technique (study group). The secondary objective was to assess the correlation between the IT and ISQ values of the two groups Materials and Methods : In the control group, 20 implants were placed in bone without bone regeneration in 15 patients, whereas in the study group, 10 implants were placed in favorable bone defects at buccal aspect with simultaneous guided bone regeneration in 7 patients. IT (Ncm) of each implant was recorded when fully inserted. ISQ values were obtained from the Osstell® ISQ at the time of implant placement, and at 2, 4, 8, and 12 weeks. The differences between two groups were analyzed by the t-test, the Mann-Whitney U test and the Repeated measures ANOVA. The Pearson and the Spearman correlation tests were used to analyze statistical correlations. All of the analyses were performed using a 95% confidence level.

Results : The mean IT values of the control group was 27.75 ± 8.96 Ncm and the study groups was 30.5 ± 8.96 Ncm. No difference in IT was found between the two groups (P = 0.502). The mean ISQ values at baseline and at 2, 4, 8, and 12 weeks of the control group were 74.30 ± 6.01, 69.58 ± 5.30, 71.10 ± 5.80, 75.08 ± 3.93 and 77.85 ± 3.18, respectively, and the mean ISQ values of the control group were 69.85 ± 7.00, 63.40 ± 8.47, 59.90 ± 10.23, 72.55 ± 3.10 and 76.20 ± 2.68. Statistically significant differences in the mean ISQ values between the control and study groups were found at 2 weeks (P = 0.021) and at 4 weeks (P = 0.007). There was no significant correlation between the IT and ISQ values of the control and study groups. Conclusions: There was no difference in IT between the control and study groups, while the difference in the changes of ISQ values during the 12 weeks healing period between implant placement without bone graft and with bone graft using the guided bone regeneration (GBR) technique were found. There was no correlation between the IT and ISQ values.