There is a need to improve the predictability of osseointegration in implant dentistry. Current literature uses a variety of in vivo titanium (Ti) implantation models to investigate failure modes, and test new materials and surfaces. However, these models produces a variety of results, making comparison across studies difficult. The purpose of this study is to validate an oral osseointegration in the Lewis rat to provide a reproducible baseline to track inflammatory response and healing of Ti implants.
Ti screws (0.76 mm Ø x 2 mm length) were implanted into the maxillary diastema of 52 adult male Lewis rats. Peri-implant tissues were evaluated 2, 7, 14, and 30 days after implantation (n = 13). Seven of the thirteen samples underwent microtomographic analysis, histology, histomorphometry and immunohistochemistry to track healing parameters. The remaining 6 samples underwent qPCR to evaluate gene expression of inflammation and bone remodeling markers over time.
This model achieved a 78.5 % success rate. Successful implants had 68.86% ± 3.15 BIC % at 30 days on average. Histologically, healing was similar to other rodent models: hematoma and acute inflammation at 2 days, initial bone formation at 7, advanced bone formation and remodeling at 14, and bone maturation at 30. qPCR indicated the highest expression of bone remodeling and inflammatory markers 2-7 days, before slowly declining to non-surgery control levels at 14-30 days.
This model combines cost-effectiveness and simplicity of a rodent model, while maximizing BIC, making it an excellent candidate for evaluation of new surfaces.
Wheelis, S. E., Biguetti, C. C., Natarajan, S., Arteaga, A., El Allami, J., Lakkasettar Chandrashekar, B., Garlet, G. P., & Rodrigues, D. C. (2021). Cellular and Molecular Dynamics during Early Oral Osseointegration: A Comprehensive Characterization in the Lewis Rat. ACS biomaterials science & engineering, 7(6), 2392–2407. https://doi.org/10.1021/acsbiomaterials.0c01420
ACS biomaterials science & engineering