A 1-Year Controlled Clinical Trial of Immediate Implants Placed in Fresh Extraction Sockets: Stability Measurements and Crestal Bone Level Changes

Abstract

The aim of this study was to measure stability and crestal bone level changes of implants placed in fresh extraction sockets in elderly patients. Thirty-five patients who were in need of tooth extractions were recruited for this study. They received a total of 65 implants in both jaws to support fixed or removable prostheses. The teeth were carefully extracted, the implants set directly in the root socket, and resonance frequency analysis (RFA) measurements were simultaneously performed (Time 1=T1). After a healing time of 6 to 10weeks the measurements were repeated (Time 2=T2). Orthograd periapical radiographs were taken when the new prostheses were fabricated and after 1year of loaded period. The distance between the first visible bone implant contact (BIC) and the implant-shoulder was measured and crestal bone loss was calculated (ΔBIC). Mean RFA and BIC were compared for various subgroups (p<.05). By means of a fixed effects model, the impact of the parameters gender, jaw, and prosthetic indication on RFA measurements was analyzed (p<.016). The mean implant stability quotient (ISQ) values were 64.4±6.7 at T1 and 64.0±at 8.6T2, with a trend to higher values for male patients. The mixed model showed that only the jaw had a statistically significant impact on ISQ values, with higher values for the mandible. Mean crestal bone loss was small with 0.49±0.81mm, ranging form 0.1 to 2.4mm. Twenty percent of the implant sites lost more than 1-mm crestal bone. No differences were found in subgroups. Good primary and secondary stability of the implants was reached in both jaws. Crestal bone loss was small but may not be fully predictable for a single site. This treatment modality can be applied successfully in elderly patients and can be suggested for various prosthetic indications in both jaws.