Evaluation of the osseointegration of titanium implants with different surface treatments and association with strontium: a preclinical study in rats

Abstract

With the technical, scientific, and industrial advancement, the variety of surface characteristics and possibilities for the surface treatment of titanium opens an opportunity to improve its biological performance. Accelerating the osseointegration process has been investigated, in an attempt to shorten the installation of the final prosthesis and extend the longevity of rehabilitation treatments. Nanobiotechnology in Implantology has emerged in the evolution of microtopography studies, seeking to investigate the tissue interactions between the physical/chemical changes of the implants and their relationship with the remaining bone portion. The macrometric and nanometric characteristics of the implant surface will determine ion exchange with the adjacent bone. The treatment with alkaline surfaces and acids is well-described in the literature, demonstrating favorable bioactivity and increased osseointegration performance. The addition of metals, especially strontium (Sr) has a great advantage, where several studies demonstrate its beneficial effects for the treatment of osteoporosis, bone pain, treatment of bone cancer, increased alkaline phosphatase, and collagen synthesis. Given the above, the objective of this preclinical study is to evaluate in rats (Rattus Norvegicus) (n = 64) the osteogenic potential and the biocompatibility of commercially pure titanium implants (Tip), with chemical treatment (acid and alkaline) of the surface, associated or not with subsequent addition of strontium. Thus, 4 experimental groups will be compared (n=16/group): G1- implants without surface treatment - Tip (Control); G2- acid + basic surface treatment - Tip H2PO4 + NaOH, G3- similar to G2 + strontium addition by the hydrothermal method - Ticp + H2PO4 + NaOH + Sr1, G4 - similar to G2 + chemical incorporation of strontium Ticp H2PO4 + NaOH + Sr2. The implants will be installed bilaterally in the tibias of the animals, totaling 128 samples, following the ISO 22911: 2016 standardization. In the experimental periods of 15 and 45 days, the animals will be euthanized to remove the bone tissue containing the implants. At that moment, the implant removal torque will be evaluated. After, the samples will be processed for the semi-quantitative histomorphometric evaluation of the biological effect, bone-implant contact (BIC - bone-implant contact), and formed bone area (BA - bone area). For statistical analysis of the data, the Shapiro-Wilk test will be applied to assess normality, followed by appropriate statistical tests, parametric or not, for multivariate analysis. The significance level of 5% will be considered for all analyzes.(AU)