Dental restorative materials with antimicrobial properties can inhibit bacterial colonization, which may result in a reduction of caries at tooth-filling interaction zones. This study aimed to develop antibacterial gl...Dental restorative materials with antimicrobial properties can inhibit bacterial colonization, which may result in a reduction of caries at tooth-filling interaction zones. This study aimed to develop antibacterial glass-ionomer cements （GIC） containing a quaternary ammonium monomer （dimethylaminododecyl methacrylate, DMADDM）, and to investigate their effect on material performance and antibacterial properties. Different mass fractions （0, 1.1% and 2.2%） of DMADDM were incorporated into the GIC. The flexure strength, surface charge density, surface roughness and fluoride release were tested. A Streptococcus mutans biofilm model was used. Exopolysaccharides （EPS） staining was used to analyze the inhibitory effect of DMADDM on the biofilm matrix. In addition, biofilm metabolic activity, lactic acid metabolism and the expression of glucosyltransferase genes g/fB, gtfC and gtfD were measured. GIC containing 1.1% and 2.2% DMADDM had flexural strengths matching those of the commercial control （P〉0.1）. DMADDM was able to increase the surface charge density but reduced surface roughness （P〈0.05）. The incorporation of 1.1% and 2.2% DMADDM elevated the release of fluoride by the GIC in the first 2 days （P〈0.05）. The novel DMADDM-modified GIC significantly reduced biofilm metabolic activity （P〈 0.05） and decreased lactic acid production （P〈 0.05）. The quantitative polymerase chain reaction （qPCR） results showed that the expression of gtfB, g/fC and gtfD decreased when mass fractions of DMADDM increased （P〈0.05）. EPS staining showed that both the bacteria and EPS in biofilm decreased in the DMADDM groups. The incorporation of DMADDM could modify the properties of GIC to influence the development of S. mutans biofilms. In this study, we investigated the interface properties of antibacterial materials for the first time. GIC containing DMADDM can improve material performance and antibacterial properties and may contribute to the better management of secondary caries.展开更多
Antibacterial adhesives are promising to inhibit biofilms and secondary caries. The objectives of this study were to synthesize and incorporate quaternary ammonium methacrylates into adhesives, and investigate the alk...Antibacterial adhesives are promising to inhibit biofilms and secondary caries. The objectives of this study were to synthesize and incorporate quaternary ammonium methacrylates into adhesives, and investigate the alkyl chain length effects on three-dimensional biofilms adherent on adhesives for the first time. Six quaternary ammonium methacrylates with chain lengths of 3, 6, 9, 12, 16 and 18 were synthesized and incorporated into Scotchbond Multi-Purpose. Streptococcus mutans bacteria were cultured on resin to form biofilms. Confocal laser scanning microscopy was used to measure biofilm thickness, live/dead volumes and live-bacteria percentage vs. distance from resin surface. Biofilm thickness was the greatest for Scotchbond control; it decreased with increasing chain length, reaching a minimum at chain length 16. Live-biofilm volume had a similar trend. Dead-biofilm volume increased with increasing chain length. The adhesive with chain length 9 had 37% live bacteria near resin surface, but close to 100% live bacteria in the biofilm top section. For chain length 16, there were nearly 0% live bacteria throughout the three-dimensional biofilm. In conclusion, strong antibacterial activity was achieved by adding quaternary ammonium into adhesive, with biofilm thickness and live-biofilm volume decreasing as chain length was increased from 3 to 16. Antibacterial adhesives typically only inhibited bacteria close to its surface; however, adhesive with chain length 16 had mostly dead bacteria in the entire three-dimensional biofilm. Antibacterial adhesive with chain length 16 is promising to inhibit biofilms at the margins and combat secondary caries.展开更多
基金supported by a National Natural Science Foundation of China grant 81372889 (Lei Cheng), 81430011 (Xue-dong Zhou)the Program for New Century Excellent Talents in University (Lei Cheng)+3 种基金a Youth Grant of the Science and Technology Department of Sichuan Province, China 2014JQ0033 (Lei Cheng)the International Science and Technology Cooperation Program of China 2014DFE30180 (Xue-dong Zhou)NIH R01 DE17974 (Hockin HK Xu)a Seed Grant (Hockin HK Xu) from the University of Maryland School of Dentistry
文摘Dental restorative materials with antimicrobial properties can inhibit bacterial colonization, which may result in a reduction of caries at tooth-filling interaction zones. This study aimed to develop antibacterial glass-ionomer cements （GIC） containing a quaternary ammonium monomer （dimethylaminododecyl methacrylate, DMADDM）, and to investigate their effect on material performance and antibacterial properties. Different mass fractions （0, 1.1% and 2.2%） of DMADDM were incorporated into the GIC. The flexure strength, surface charge density, surface roughness and fluoride release were tested. A Streptococcus mutans biofilm model was used. Exopolysaccharides （EPS） staining was used to analyze the inhibitory effect of DMADDM on the biofilm matrix. In addition, biofilm metabolic activity, lactic acid metabolism and the expression of glucosyltransferase genes g/fB, gtfC and gtfD were measured. GIC containing 1.1% and 2.2% DMADDM had flexural strengths matching those of the commercial control （P〉0.1）. DMADDM was able to increase the surface charge density but reduced surface roughness （P〈0.05）. The incorporation of 1.1% and 2.2% DMADDM elevated the release of fluoride by the GIC in the first 2 days （P〈0.05）. The novel DMADDM-modified GIC significantly reduced biofilm metabolic activity （P〈 0.05） and decreased lactic acid production （P〈 0.05）. The quantitative polymerase chain reaction （qPCR） results showed that the expression of gtfB, g/fC and gtfD decreased when mass fractions of DMADDM increased （P〈0.05）. EPS staining showed that both the bacteria and EPS in biofilm decreased in the DMADDM groups. The incorporation of DMADDM could modify the properties of GIC to influence the development of S. mutans biofilms. In this study, we investigated the interface properties of antibacterial materials for the first time. GIC containing DMADDM can improve material performance and antibacterial properties and may contribute to the better management of secondary caries.
基金supported by NIH R01 DE17974West China School of Stomatologya Seed Grant from Department of Endodontics,Prosthodontics and Operative Dentistry,University of Maryland
文摘Antibacterial adhesives are promising to inhibit biofilms and secondary caries. The objectives of this study were to synthesize and incorporate quaternary ammonium methacrylates into adhesives, and investigate the alkyl chain length effects on three-dimensional biofilms adherent on adhesives for the first time. Six quaternary ammonium methacrylates with chain lengths of 3, 6, 9, 12, 16 and 18 were synthesized and incorporated into Scotchbond Multi-Purpose. Streptococcus mutans bacteria were cultured on resin to form biofilms. Confocal laser scanning microscopy was used to measure biofilm thickness, live/dead volumes and live-bacteria percentage vs. distance from resin surface. Biofilm thickness was the greatest for Scotchbond control; it decreased with increasing chain length, reaching a minimum at chain length 16. Live-biofilm volume had a similar trend. Dead-biofilm volume increased with increasing chain length. The adhesive with chain length 9 had 37% live bacteria near resin surface, but close to 100% live bacteria in the biofilm top section. For chain length 16, there were nearly 0% live bacteria throughout the three-dimensional biofilm. In conclusion, strong antibacterial activity was achieved by adding quaternary ammonium into adhesive, with biofilm thickness and live-biofilm volume decreasing as chain length was increased from 3 to 16. Antibacterial adhesives typically only inhibited bacteria close to its surface; however, adhesive with chain length 16 had mostly dead bacteria in the entire three-dimensional biofilm. Antibacterial adhesive with chain length 16 is promising to inhibit biofilms at the margins and combat secondary caries.
