In vivo models for evaluating antibacterial activity and osseointegration of dual-biofunctional implant coatings: A systematic review

This systematic review assesses the necessity of <i>in vivo</i> models in determining whether these novel dual-biofunctional coating could induce osseointegration and exhibit antibacterial activity by providing a comprehensive biological response that <i>in vitro</i> models cannot replicate. This systematic review included <i>in vivo</i> studies involving intraoral implantation. A comprehensive search of original research published in English up to December 2024 was conducted across Medline, Scopus, and Web of Science. From the screened studies, 16 studies (1 clinical trial and 15 animal studies) met the inclusion criteria. The clinical trial involved 15 patients and reported 4-month outcomes. A large variance was observed among the protocol of animal studies, comprising five species (rats, rabbits, dogs, pigs, and goats). Six studies utilized peri-implantitis models to evaluate osseointegration outcomes under disease challenge. The reviewed studies highlighted various osseointegration-promoting components, such as inorganic compounds (e.g., calcium phosphate), peptides, and metal-based materials, as well as antimicrobial agents including metals, metal oxides, and polymers. By synthesizing <i>in vivo</i> findings, this review seeks to optimize dual-biofunctional coatings that simultaneously eradicate pathogenic bacteria and induce osseointegration within clinically relevant environments. Future work should aim to standardize <i>in vivo</i> protocols and new <i>in vitro</i> methods to reduce heterogeneity.