Effect of bacterial cellulose nanocrystal and 2-methacryloyloxyethyl phosphorylcholine incorporation on the mechanical properties of resin-modified glass ionomer cement

Background and purpose Resin-modified glass ionomer cements (RMGICs) are commonly utilized as restorative materials because of their ability to release fluoride, form chemical bonds with tooth structure, and desirable biocompatibility. Nevertheless, their comparatively low mechanical strength limits their application in regions subjected to high stress. This study sought to investigate how the addition of bacterial cellulose nanocrystals (BCNC) and 2-methacryloyloxyethyl phosphorylcholine (MPC) influences the mechanical performance of RMGICs. Materials and methods A total of 192 samples were prepared in four groups (n = 48/group): Group 1, unmodified RMGIC (control group); Group 2, RMGIC with 1 wt% BCNC; Group 3, RMGIC with 3 wt% MPC; and Group 4, RMGIC with 1 wt% BCNC and 3 wt% MPC. Each group was evaluated for flexural strength (FS), diametral tensile strength (DTS), surface roughness (SR), and microhardness (MH). Data were analyzed using SPSS version 25; a p value < 0.05 was considered statistically significant. Results Groups 1 (unmodified RMGIC) and Group 2 (RMGIC with BCNC) demonstrated significantly higher DTS values than Group 4 (RMGIC with BCNC and MPC). Group 3 (RMGIC with MPC) exhibited lower FS and higher SR compared to Groups 1, 2, and 4. While MH of all experimental groups was comparable to Group 1, Group 4 had significantly lower MH compared with Groups 2 and 3. Conclusion BCNC incorporation into RMGIC did not significantly alter the mechanical properties. In contrast, MPC compromised FS, DTS, and SR. RMGIC with both BCNC and MPC demonstrated comparable FS, SR, and MH to unmodified RMGIC, while its DTS was significantly lower than unmodified RMGIC.