Biomaterials for controlling dental implant infections: biological mechanisms, modulating factors, and new treatment strategies

Author(s)

Raphael Cavalcante Costa

• Document type: Doctoral Thesis
• Press: Piracicaba, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba (FOP)
• Defense date: 2023-06-16

Examining board members

Valentim Adelino Ricardo Barão; Karina Gonzales Silverio; Marlise Inês Klein Furlan; Érica Dorigatti de Avila; Diana Gabriela Soares

• Advisor: Valentim Adelino Ricardo Barão; João Gabriel Silva Souza

Abstract

Peri-implant infections are chronic inflammatory diseases associated with a pathogenic microbial community that progressively affects the integrity of supporting tissues. Current clinical therapies aim to remove biofilm mechanically and occasionally with adjuvant antimicrobial approaches without considering the role of surfaces and inflammation. Thus, this approach is not always effective, especially for reversing biofilm dysbiosis and controlling inflammation. In this context, therapeutic strategies are being developed to prevent peri-implant infections and increase the success rates of rehabilitations with implants. This thesis work aims to describe the state of the art and emerging research on the use of biomaterials to control infections/inflammation in dental implants. An evidence-based critical review was initially developed to summarize preclinical and clinical studies on proposed emerging antimicrobial surfaces for titanium (Ti)-based implants [Study 1]. The findings of this review suggest that there is no available Ti surface capable of reducing oral bacterial accumulation and preventing polymicrobial infections. In addition to implant surfaces, future research should focus on understanding the etiopathogenesis and modulating factors of biofilm on Ti as a strategy to improve anti-biofilm therapies, such as biofilm extracellular matrix (EM). ME is widely discussed on tooth surfaces, but its effect on the pathogenesis of implant infections has been neglected. Therefore, a review of the state of the art on the role of ME on Ti surfaces was developed [Study 2]. The summarized results indicate that ME is an important virulence factor, contributing to bacterial colonization, antimicrobial resistance and pathogenesis and should be considered in the development of new therapies. Motivated by these reviews and the absence of a clinical treatment protocol based on ME degradation, an in vitro and in situ research was conducted [Study 3]. A 3-step decontamination protocol for Ti surfaces using povidone-iodine (0.2%) as an ME degradation agent was shown to be effective and safe, eliminating biofilms without damaging the implant surface or affecting cell adhesion. In addition, the association of antimicrobial therapies with immunomodulators is still scarce in implant dentistry. Therefore, we developed a new biomaterial for folate release aiming to improve antimicrobial strategy via modulation of tissue inflammation [Study 4]. In summary, the molecularly imprinted polymer loaded with folate proved to be a promising strategy for controlling inflammation in vitro and in vivo. The results of this Thesis support the indication of a new non-surgical therapy that should be clinically tested for the control of dental implant infections (AU)

• FAPESP's process: 20/10436-4 - Synthesis, characterization and biological performance of pH-sensitive nanopolymers produced by molecular printing for the treatment of peri-implant infections
• Grantee: Raphael Cavalcante Costa
• Support Opportunities: Scholarships in Brazil - Doctorate