Novel Bioactive Nanocomposites Containing Calcium Fluoride and Calcium Phosphate with Antibacterial and Low-Shrinkage-Stress Capabilities to Inhibit Dental Caries

Abstract

Objectives: Composites are commonly used for tooth restorations, but recurrent caries often lead to restoration failures due to polymerization shrinkage-stress-induced marginal leakage. The aims of this research were to: (1) develop novel low-shrinkage-stress (L.S.S.) nanocomposites containing dimethylaminododecyl methacrylate (DMADDM) with nanoparticles of calcium fluoride (nCaF2) or amorphous calcium phosphate (NACP) for remineralization; (2) investigate antibacterial and cytocompatibility properties. Methods: Nanocomposites were made by mixing triethylene glycol divinylbenzyl ether with urethane dimethacrylate containing 3% DMADDM, 20% nCaF2, and 20% NACP. Flexural strength, elastic modulus, antibacterial properties against Streptococcus mutans biofilms, and cytotoxicity against human gingival fibroblasts and dental pulp stem cells were tested. Results: Nanocomposites with DMADDM and nCaF2 or NACP had flexural strengths matching commercial composite control without bioactivity. The new nanocomposite provided potent antibacterial properties, reducing biofilm CFU by 6 logs, and reducing lactic acid synthesis and metabolic function of biofilms by 90%, compared to controls (p < 0.05). The new nanocomposites produced excellent cell viability matching commercial control (p > 0.05). Conclusions: Bioactive L.S.S. antibacterial nanocomposites with nCaF2 and NACP had excellent bioactivity without compromising mechanical and cytocompatible properties. The new nanocomposites are promising for a wide range of dental restorations by improving marginal integrity by reducing shrinkage stress, defending tooth structures, and minimizing cariogenic biofilms.

Novel Remineralizing and Antibiofilm Low-Shrinkage-Stress Nanocomposites to Inhibit Salivary Biofilms and Protect Tooth Structures

“…Subsequently, DMADDM was introduced into our formulations, comprising a final mass fraction of 3%. nCaF 2 (particle size = 32 nm) and NACP (particle size = 116 nm) nanoparticles were synthesized utilizing a spray-drying process, as described in previous studies [31,32]. To ensure strong mechanical characteristics and promote remineralization, nCaF 2 , and NACP fillers were added to the final novel composite at a mass fraction of 20% [31].…”

“…An alternative approach to preventing the development of recurrent caries involves incorporating remineralization filler, such as nano-fluorapatite, nano-hydroxyapatite, nanosized calcium fluoride (nCaF 2 ) or nano-sized amorphous calcium phosphate (NACP), into resin-based materials [29][30][31]. These fillers provide a practical method for introducing bioactivity.…”

“…This approach holds promise in reducing demineralization and improving the longevity of resin composites. Our recent investigation aimed to develop a bioactive low-shrinkage-stress nanocomposite containing 3% DMADDM, along with either nCaF 2 or NACP [31]. These novel formulations exhibited potent antibiofilm effects without compromising the mechanical properties and cell viability of dental pulp stem cells and human gingival fibroblasts [31].…”

“…Our recent investigation aimed to develop a bioactive low-shrinkage-stress nanocomposite containing 3% DMADDM, along with either nCaF 2 or NACP [31]. These novel formulations exhibited potent antibiofilm effects without compromising the mechanical properties and cell viability of dental pulp stem cells and human gingival fibroblasts [31]. However, the antibiofilm efficacy of these formulations was assessed against an S. mutans biofilm [15,31].…”

“…These novel formulations exhibited potent antibiofilm effects without compromising the mechanical properties and cell viability of dental pulp stem cells and human gingival fibroblasts [31]. However, the antibiofilm efficacy of these formulations was assessed against an S. mutans biofilm [15,31]. However, to date, there has been no report on the release of ions and the antibiofilm properties against complex biofilm models when incorporating DMADDM with NACP and nCaF 2 in a low-shrinkage-stress nanocomposite.…”