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OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: This model combines cost-effectiveness and simplicity of a rodent model, while maximizing BIC, making it an excellent candidate for evaluation of new surfaces.

Made available in DSpace on 2020-12-12T02:24:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-02-10 Dicationic imidazolum-based ionic liquids with amino acid anions (IonL) have been proposed as a multifunctional coating for titanium dental implants, as their properties have been shown to address multiple early complicating factors while maintaining host cell compatibility. This study aims to evaluate effects of this coating on host response in the absence of complicating oral factors during the early healing period using a subcutaneous implantation model in the rat. IonLs with the best cytocompatibility and antimicrobial properties (IonL-Phe, IonL-Met) were chosen as coatings. Three different doses were applied to cpTi disks and subcutaneously implanted into 36 male Lewis rats. Rats received two implants: one coated implant on one side and an uncoated implant on the contralateral sides (n = 3 per formulation, per dose). Peri-implant tissue was evaluated 2 and 14 days after implantation with H&E staining and IHC markers associated with macrophage polarization as well as molecular analysis (qPCR) for inflammatory and healing markers. H&E stains revealed the presence of the coating, blood clots, and inflammatory infiltrate at 2 days around all implants. At 14 days, inflammation had receded with more developed connective tissue with fibroblasts, blood vessels in certain doses of coated and uncoated samples with no foreign body giant cells. This study demonstrated that IonL at the appropriate concentration does not significantly interfere with healing and Ti foreign body response. Results regarding optimal dose and formulation from this study will be applied in future studies using an oral osseointegration model. Deparment of Bioengineering University of Texas at Dallas Department of Basic Sciences São Paulo State University (UNESP) School of Dentistry Department of Biological Sciences University of Texas at Dallas Bauru School of Dentistry Department of Biological Sciences University of São Paulo Department of Basic Sciences São Paulo State University (UNESP) School of Dentistry