Examination of explants by electron microscopy and correlations with the biomechanical score of prosthetic restorations with implant support

Objectives. The objective of our study was to evaluate the bone-implant interface in 10 cases of failure of fixed implant-prosthetic treatment by electron microscopy and spectrophotometry, in correlation with the evolution of Renouard-Rangert biomechanical scoring. Material and method. The study material was represented by 10 dental implants of 3 different morphological types (A, B, C), from the Biomat © collection, Polytechnic University of Bucharest, which were examined under the Phenom ProX electron microscope. The studied samples had a file in which there was noted the biomechanical score Renouard-Rangert from the treatment planning phase, but also from the patient dispensary phase. The survival time of the analyzed samples at the level of the maxillary bones was 7-24 months. Results. Following the examination at the electron microscope, the presence of an adherent neoformation bone tissue was detected on every implant, which covered each implant relatively uniform, with different degrees of mineralization depending on the type of implant, the duration of bone implantation and evolution of biomechanical scoring in red or yellow. Discussions. The use in our study only of standard size implants is an important advantage over other studies using mini-implants or temporary implants. The cases in which the biomechanical scoring reached "red" showed a lower degree of mineralization, and those that reached "yellow" had a higher degree of mineralization. Among the cases with biomechanical soring "in yellow" were samples collected from the posterior maxillary region, generally considered a risk area in implantology. Conclusions. In our study we found a correspondence between the modification of the Renouard-Rangert biomechanical scoring and the degree of mineralization of the bone deposited on the surface of the explants. Regardless of the evolution of biomechanical scoring, on all 10 analyzed samples we found a close contact between the neoformation tissue and the implanted devices, which indicates the high biocompatibility of the three types of implants. The relatively small number of samples analyzed is a limitation of our study. In the future, we recommend, in order to validate the results, to extend the study to a greater number of cases.