IADR Abstract Archives
Antimicrobial Pit and Fissure Sealant Using K18-MMA and K18-Filler
Objectives: To determine the effects of quaternary ammonium methacryloxy silane (K18 QAMS) and K18-functionalized filler (K18-filler) on the cure, esthetic, mechanical, shear bond, and antimicrobial properties of the sealant and develop an antimicrobial pit and fissure sealant.
Methods: 30 wt% K18 QAMS dissolved in methyl methacrylate (K18-MMA) (0-20 wt%) was added to a blend of urethane dimethacrylate, hydroxypropyl methacrylate, and 2-hydroxyethyl methacrylate phthalic anhydride monomer and left unfilled or filled to 60 wt% with 0.7 µm glass filler or K18-filler. Controls included unfilled resins without K18-MMA and UltraSeal™ XT. Specimens were light cured and tested for hardness (Rockwell15T), degree of monomer-to-polymer conversion (DoC, near-infrared FTIR), hydrophilicity (contact angle), transparency (Transparency Parameter, TP), color shift (ΔE), mechanical (3-point bend test), and shear bond properties. Data were analyzed using ANOVA and Tukey HSD post hoc test for significance at p<0.05.
Results: Filling the resins increased Rockwell15T hardness from 57-58RHN to 68-73RHN (p=0.000). Adding 20 wt% K18-MMA and filler decreased DoC from 85%-96% to 77%-82% (p<0.001), probably due to the filler reducing transparency (TP from 68.8-69.6 to 15.0-20.9, p=0.000) and increasing color shift (ΔE from 3.3-7.7 to 11.0-12.9). There were no clear trends in contact angles, and all groups had contact angles greater than 90 degrees. Filling resins significantly increased modulus from 883-940MPa to 1809-2039MPa (p=0.000). UltraSeal™ had a modulus of 1234±97MPa. Adding filler, especially K18-filler, reduced strength from 88.7-100.3MPa to 68.0-99.7MPa. UltraSeal™ had a strength of 98.9±14.8MPa. Increasing K18-MMA concentration decreased shear bond strength, but addition of filler reversed that. All K18 groups had greater shear bond strength (12.87-22.01MPa) than UltraSeal™ (8.2MPa).
Conclusions: Sealants with K18-MMA and K18-filler with comparable cure, esthetic, mechanical and shear bond properties to commercial pit and fissure sealants have been developed. Antimicrobial activity against Streptococcus mutans, Streptococcus sanguinis and Candida albicans are currently being conducted.
Methods: 30 wt% K18 QAMS dissolved in methyl methacrylate (K18-MMA) (0-20 wt%) was added to a blend of urethane dimethacrylate, hydroxypropyl methacrylate, and 2-hydroxyethyl methacrylate phthalic anhydride monomer and left unfilled or filled to 60 wt% with 0.7 µm glass filler or K18-filler. Controls included unfilled resins without K18-MMA and UltraSeal™ XT. Specimens were light cured and tested for hardness (Rockwell15T), degree of monomer-to-polymer conversion (DoC, near-infrared FTIR), hydrophilicity (contact angle), transparency (Transparency Parameter, TP), color shift (ΔE), mechanical (3-point bend test), and shear bond properties. Data were analyzed using ANOVA and Tukey HSD post hoc test for significance at p<0.05.
Results: Filling the resins increased Rockwell15T hardness from 57-58RHN to 68-73RHN (p=0.000). Adding 20 wt% K18-MMA and filler decreased DoC from 85%-96% to 77%-82% (p<0.001), probably due to the filler reducing transparency (TP from 68.8-69.6 to 15.0-20.9, p=0.000) and increasing color shift (ΔE from 3.3-7.7 to 11.0-12.9). There were no clear trends in contact angles, and all groups had contact angles greater than 90 degrees. Filling resins significantly increased modulus from 883-940MPa to 1809-2039MPa (p=0.000). UltraSeal™ had a modulus of 1234±97MPa. Adding filler, especially K18-filler, reduced strength from 88.7-100.3MPa to 68.0-99.7MPa. UltraSeal™ had a strength of 98.9±14.8MPa. Increasing K18-MMA concentration decreased shear bond strength, but addition of filler reversed that. All K18 groups had greater shear bond strength (12.87-22.01MPa) than UltraSeal™ (8.2MPa).
Conclusions: Sealants with K18-MMA and K18-filler with comparable cure, esthetic, mechanical and shear bond properties to commercial pit and fissure sealants have been developed. Antimicrobial activity against Streptococcus mutans, Streptococcus sanguinis and Candida albicans are currently being conducted.