Antimicrobial hard denture reliners using quaternary ammonium methacryloxy silicate (K18 QAMS) and K18-functionalized filler.

OBJECTIVE

To determine the effects of adding a quaternary ammonium methacryloxy silicate (K18) and K18-functionalized filler (K18-Filler) on the material and antimicrobial properties of a hard denture reline material.

MATERIALS AND METHODS

30% K18 in methyl methacrylate (K18-MMA; 0-20 wt% of reliner) and K18-Filler (0-30 wt% of reliner) were incorporated into Kooliner hard denture reliner. Kooliner served as the control. The cure (Shore A hardness), hydrophilicity (contact angles), mechanical (3-point bend test), water sorption, and antimicrobial properties against , , and were determined.

RESULTS

Most K18 groups cured well and had comparable Shore A hardness values (range ~52 to 70 DHN) to that of controls (67.2 ± 1.8 DHN; Bonferroni corrected  > 0.0003). Even the softest group had hardness values within the range of commercial products. Half of the K18 groups had comparable contact angles to that of controls (range ~75° to 80° vs 83.41° ± 2.66°; Bonferroni corrected  > 0.0003), and most were within the range of commercial liners. K18-MMA and K18-Filler increased modulus but decreased ultimate transverse strength (UTS). All experimental groups had comparable or higher moduli than controls (range ~966 to 2069 MPa vs 1340 ± 119 MPa; Bonferroni corrected  < 0.0003), but only half of the experimental groups had comparable UTS to that of controls (range ~41 to 49 MPa vs 55.8 ± 1.5 MPa; Bonferroni corrected  > 0.0003). The 15% and 20% K18-MMA with 30% K18-Filler groups had significant antimicrobial activity against all three microbes ( < 0.05). However, the 15% and 20% K18-MMA with 30% K18-Filler groups had significantly higher water sorption at early time points ( < 0.05). After 8 weeks, they were comparable to each other ( > 0.05).

CONCLUSIONS

K18-MMA and K18-Filler are promising antimicrobial additives that produce hard denture liners with material properties within the range of commercial products and significant antimicrobial properties against , , and . Further development is needed to reduce water sorption.