Assessment of the Tissue Response to Modification of the Surface of Dental Implants with Carboxyethylphosphonic Acid and Basic Fibroblastic Growth Factor Immobilization (Fgf-2): An Experimental Study on Minipigs

Abstract

The aim of this study was to evaluate the effect of implant surface treatment with carboxyethylphosphonic acid and fibroblast growth factor 2 on the bone–implant interface during the osseointegration period in vivo using an animal model. The present research was carried out in six minipigs, in whose left tibia implants were inserted as follows: eight implants with a standard surface treatment, for the control group, and eight implants with a surface treatment of carboxyethylphosphonic acid and immobilization of FGF-2, for the test group. At 4 weeks after the insertion of the implants, the animals were sacrificed for the histomorphometric analysis of the samples. The means of the results for the implant–bone contact variable (BIC) were 46.39 ± 17.49% for the test group and 34.00 ± 9.92% for the control group; the difference was not statistically significant. For the corrected implant–bone contact variable (BICc), the mean value of the test group was 60.48 ± 18.11%, and that for the control group, 43.08 ± 10.77%; the difference was statistically significant (p-value = 0.035). The new bone formation (BV/TV) showed average results of 27.28 ± 3.88% for the test group and 26.63 ± 7.90% for the control group, meaning that the differences were not statistically significant (p-value = 0.839). Regarding the bone density at the interthread level (BAI/TA), the mean value of the test group was 32.27 ± 6.70%, and that of the control group was 32.91 ± 7.76%, with a p-value of 0.863, while for the peri-implant density (BAP/TA), the mean value of the test group was 44.96 ± 7.55%, and that for the control group was 44.80 ± 8.68%, without a significant difference between the groups. The current research only found a significant difference for the bone–implant contact at the cortical level; therefore, it could be considered that FGF-2 acts on the mineralization of bone tissue. The application of carboxyethylphosphonic acid on the surface of implants can be considered a promising alternative as a biomimetic coating for the immobilization of FGF-2. Despite no differences in the new bone formation around the implants or in the interthread or peri-implant bone density being detected, the biofunctionalization of the implant surface with FGF-2 accelerates the mineralization of the bone–implant interface at the cortical level, thereby reducing the osseointegration period.

Role of BMP-7 on biological parameters osseointegration of dental implants: Preliminary results of a preclinical study

“…Therefore, manufacturers have subjected dental implants to different technical approaches, based on etching, blasting or a combination of both (Khang et al, 2001;Fini et al, 2003;Szmukler-Moncler et al, 2004;Le Guéhennec et al, 2007;Wennerberg and Albrektsson, 2009;Leon-Ramos et al, 2019) with the aim of increasing the surface roughness and, consequently, the success rate of osseointegration. In particular, it has been described that the application of carboxyethylphosphonic acid (CEPA), enhances the osseointegration process, improving protein adhesion, after generating a physicochemical layer of Al 2 O 3 or TiO 2 (Aragoneses et al, 2021). On the other hand, conventional surface treatments (Sandblasted Large-Grit Acid-Etched, SLA type) have shown enhanced osseointegrative power when combined with surface bioactivation, based on the immobilization of proteins, enzymes or peptides, which could induce a specific cellular response in peri-implant tissues in the early stages of osseointegration (López-Valverde et al, 2020).…”