Bio-Tribocorrosion of Titanium Dental Implants in the Oral Environment: A Narrative Review.

Titanium and its alloys are widely used in dental implantology because of their favorable mechanical properties, corrosion resistance, and biocompatibility. However, long-term clinical success of dental implants is increasingly challenged by material degradation processes occurring in the complex oral environment. Tribocorrosion, a synergistic phenomenon involving mechanical wear and electrochemical corrosion, has emerged as a critical mechanism contributing to implant surface deterioration. When biological factors such as oral biofilms, saliva, inflammatory mediators, and fluctuating pH are incorporated into this interaction, the process is termed bio-tribocorrosion. This narrative review provides a comprehensive overview of the fundamental principles of tribocorrosion and extends them to the context of bio-tribocorrosion affecting titanium dental implants. The mechanisms underlying the synergism between mechanical loading and chemical or electrochemical degradation are discussed, along with factors influencing bio-tribocorrosion in the oral cavity, including implant material composition, surface characteristics, biofilm formation, fluoride exposure, salivary components, mastication-induced micromovements, and galvanic interactions. The biological consequences of titanium ion and particle release are critically examined, with emphasis on cytotoxicity, inflammatory responses, immune modulation, hypersensitivity reactions, peri-implant tissue breakdown, and bone loss. Evidence linking titanium wear debris to peri-implantitis and implant failure is reviewed, and current in vitro tribocorrosion testing methodologies and their limitations are summarized. Finally, emerging strategies aimed at mitigating bio-tribocorrosion, such as alloy development, surface modifications, protective coatings, and alternative biomaterials, are discussed. Understanding bio-tribocorrosion is essential for improving implant longevity, minimizing biological complications, and guiding future innovations in dental implant materials and design.