Uncovering interactions between bioderived nanomaterials and water in novel dental adhesives: strategies for reduced moisture sensitivity

About This Grant

Project Summary The overarching goal of this R03 proposal is reduce the moisture sensitivity of dental adhesives by incorporating cellulose nanocrystals (CNCs). This work is motivated by prior research in related engineering applications (e.g., pressure sensitive adhesives, coatings) demonstrating that CNCs decrease moisture sensitivity of polymeric matrices. Despite this prior art, systematic investigation of CNC impact on dental adhesive materials has yet to be undertaken. This constitutes a major gap, as moisture sensitivity is a significant contributor to the high rate of secondary caries and therefore identifying benign materials that can address this issue is of utmost importance. Furthermore, the proposed specific aims will determine fundamental interactions between CNCs and water, determining if ‘bound’ water within a polymerized adhesive delays or eliminates water-mediated degradation mechanisms. I am qualified to lead this project, as previous and ongoing work from my research team investigates reduced water sensitivity in food packaging and adhesive materials modified with cellulose nanomaterials. Furthermore, my expertise in photopolymerized polymer networks employed as dental materials complements this expertise and makes me uniquely qualified to oversee this investigation. Building upon this foundation and expertise, the overarching hypothesis for this proposal is that long-term stability of the adhesive layer will be enhanced when CNCs are uniformly incorporated and distributed within a photopolymerized dental adhesive. This project consists of two Specific Aims. In Specific Aim 1, I will determine how the distribution of CNCs varies based on the composition of model self-etch adhesives, and how this distribution impacts moisture sensitivity, network properties, and adhesive performance when exposed to moisture. This is motivated by the high degree of heterogeneity associated with currently employed adhesive systems. In Specific Aim 2, different surface functionalizations will be explored to optimize and modify the distribution of CNCs within adhesive networks and potentially improve the impact of these additives on adhesive performance. Given the heterogeneous nature of adhesive materials, I expect surface functionalization will enable more effective distribution. This area of research constitutes a new domain at this early-stage of my career, and thus the results from this award will serve as motivation to investigate a more diverse range of bio-sourced nanomaterials (e.g., functionalization, geometries) for restoration systems where biomaterial-water interactions need to be tailored.