Correlation of Implant Stability Between Two Noninvasive Methods Using Submerged and Nonsubmerged Healing Protocols: A Randomized Clinical Trial.

Various invasive and noninvasive methods have been used for measuring primary implant stability. Periotest damping device and resonance frequency analysis with the Osstell device have been classified as noninvasive methods. Primary and secondary implant stability measurements using both devices have given reproducible quantitative values. In this clinical randomized trial, a general correlation was evaluated between the implant stability recorded using both Osstell and Periotest devices on the day of implant installation and 3 months after healing for the submerged and nonsubmerged loading protocols. The present study also investigated whether the difference in gender of the included patients would have an effect on the correlation between the two devices. Eighty completely edentulous patients were recruited, and all patients ranged from 50 to 69 years of age. Overall, 56 men and 24 women were included, with a mean age of 62.5 years for men and 59.6 years for women. A single implant was installed in the midline of the completely edentulous mandible to improve retention of the patient's lower denture. After implant installation, one implant stability quotient (ISQ) value at the buccal surface was recorded, and then the Periotest M device was used to measure the damping effect (Periotest value [PTV]) of the installed implant using the smart peg screwed to the implant. Patients were then randomized into 2 groups using sealed envelopes: the submerged and nonsubmerged groups. For both groups, all ISQ and Periotest readings were recorded in the patient's case report file on the day of implant installation and 3 months after healing. When the ISQ of the buccal surface was correlated to the PTV, there was a moderate negative statistically significant correlation between the 2 readings (correlation coefficient = -.466, P = .000). There tended to be a weak negative correlation between the 2 devices in the male group (correlation coefficient = .395, P = .046) during implant installation, although there tended to be no correlation between the 2 devices in the female group (correlation coefficient = -.367, P = .342). After 3 months of healing, when correlating the readings of the buccal surface of the Osstell with that of the Periotest within each group (submerged and nonsubmerged), there was no statistically significant correlation between the readings within each group (correlation coefficient = -.014, -.430, P = .942, P = .052, respectively). However, there was a strong negative statistically significant correlation between the 2 devices for the female group for both the nonsubmerged group (correlation coefficient = -.823, P = .003) and submerged group (correlation coefficient = -.857, P = .014), whereas there was no statistically significant correlation within the male group for both the nonsubmerged group (correlation coefficient = -.377, P = .123) and submerged group (correlation coefficient = -.022, P = .940). The correlation between the Osstel and Periotest device remains controversial. The present study concluded that there is a significant negative correlation between the 2 devices when recording primary implant stability, although this significance is lost after 3 months of loading when recording secondary implant stability. Gender also affects the implant stability recording, which is mainly due to the difference in bone density between men and women.