Development of a chlorhexidine delivery system based on dental reline acrylic resins

[Display omitted] •Different acrylic reline resins loaded with chlorhexidine (CHX) were successfully prepared.•The minimal concentration of CHX that promoted antimicrobial activity was 2.5 wt% for Kooliner and 5 wt% for Ufi Gel Hard and Probase Cold.•Evaluation of the reline resins included micro-CT structural characterization and release assays conducted in artificial saliva.•Probase Cold loaded with 5 wt% CHX showed the best overall properties, including the cytotoxicity profile. The high recurrence rate of common denture stomatitis after antifungal treatment is still concerning. This condition is caused by low patient compliance and incomplete local elimination of the main etiological factor — Candida albicans, often associated with other microorganisms, such as Streptococcus species. Impregnating denture materials with antimicrobials for local delivery is a strategy that can overcome the side effects and improve the efficacy of conventional treatments (topical and/or systemic). In this work, we describe the development of three hard autopolymerizing reline acrylic resins (Kooliner, Ufi Gel Hard, and Probase Cold) loaded with different percentages of chlorhexidine (CHX). The novel formulations were characterized based on their antimicrobial activity, mechanical, morphological and surface properties, in-vitro drug release profiles, and cytotoxicity. The addition of CHX in all resins did not change their chemical and mechanical structure. Among all the tested formulations, Probase Cold loaded with 5 wt% CHX showed the most promising results in terms of antimicrobial activity and lack of serious detrimental mechanical, morphological, surface, and biological properties.