Evaluation of stability changes in magnesium-incorporated titanium implants in the early healing period.

The aim of the present study was to determine the bone response to magnesium (Mg) ion-incorporated titanium (Ti) implants during the early healing period. A total of 114 patients (69 men and 45 women aged between 29 and 71 years) participated in the study. Overall, one hundred thirty-three 10-mm-long fixtures were installed, composed of 65 Mg ion-incorporated fixtures in the test group (55 participants; 30 males and 25 females) and 68 resorbable blast media (RBM) surface fixtures in the control group (59 participants; 39 males and 20 females). The bone responses were evaluated by resonance frequency analysis (RFA) at the following time points after implant insertion (ie, the healing period): 0, 2, 4, 8, and 12 weeks. Each time an RFA measurement was taken, the stability changes relating to both bone quality and implant arch location (maxilla or mandible) were recorded for further analysis. The mean stabilities were lowest at week 4 of healing for both the test and control groups. Significant differences in RFA values between the 2 groups were found at week 12 of healing. The mean percentage change in implant stability quotient (ISQ) from the baseline revealed that the implant stability of the Mg ion-incorporated test group had increased (4.55%) more than the RBM surface group (2.23%) by week 12 of healing. With respect to bone quality, the mean ISQ of Mg-incorporated Ti implants only changed significantly during the 12-week period for type 4 bone. Furthermore, at weeks 4 and 12 of healing, significant differences were found between the 2 groups for type 2 and type 4 bone. A comparison of the stability patterns of mandibular and maxillary implants revealed that the overall stability was higher in the mandible; however, no significant difference was found for Mg-incorporated Ti implants. The Mg-incorporated Ti implants exhibited a slightly better bone response with respect to ISQ than did the RBM surface implants, and the percentage change in mean ISQ from the baseline was greater for the Mg-incorporated group than for the RBM surface group at the end point of this study.