![[ Visit AADR's Website ]](images/banner.jpg)
Recently, inhibition of host-derived MMPs by quaternary ammonium methacrylates (QAMs) showed promising results. However, the optimum use would be to incorporate QAMs into adhesive resins. Objectives: To evaluate the dentin wettability of a range of quaternary ammonium-methacrylates (QAMs). Methods: A range of commercial QAMs were added to co-monomer mixtures of TEGDMA (30 wt%), HEMA (10 wt%), and BisGMA (wt% varied) and dentin wettability was measured on mid-coronal dentin discs with contact angle measurements (DSA 30, Krüss GmbH Germany) using sessile drop method. The groups were: ATA (5, 10, 15 wt%); MCMS (5, 10, 15 wt%), METMAC (5, 10, 15 wt%); MAPTAC 5 wt%; a control without QAM (NQC); and a commercial control (Scotchbond Multipurpose Adhesive bottle (SBMP) (3M ESPE). Abbreviations defined in J Dent Res 2011;90:525-540. A 2 µL drop of resin was dispensed on a standard smear-covered, 15 s acid-etched moist dentin surface and the change in contact angle over 180 s time was evaluated using tangent drop shape analysis. Data (n=10/group) were analyzed by ANOVA and Tukey test (alpha=0.05). Results: The table presents mean contact angle degrees and (SD) of groups over time.
Reading time (s) | NQC | SBMP | ATA 5% | ATA 10% | ATA 15% | METMAC 5% | METMAC 10% | METMAC 15% | MCMS 5% | MCMS 10% | MCMS 15% | MAPTAC 5% |
0 | 49.3(4.6) | 43.1 (9.1) | 47.4 (3.6) | 46.3 (5.7) | 38.9 (5.3) | 43.5 (7.2) | 41.0 (5.3) | 41.9 (6.0) | 43.4 (5.8) | 39.7 (5.3) | 40.94(6.2) | 48.5 (4.5) |
10 | 43.8(3.2) | 39.3 (9.7) | 41.4 (3.5) | 39.6 (6.6) | 33.0 (6.5) | 38.3 (7.2) | 35.8 (5.3) | 37.3 (6.5) | 36.0 (5.9) | 34.1 (3.8) | 35.04(7.8) | 44.7 (5.7) |
180 | 41.3(7.3) | 34.0 (9.2) | 39.5 (3.8) | 32.0 (3.3) | 26.9 (7.3) | 32.1 (8.4) | 27.8 (8.6) | 27.6 (9.6) | 29.0 (6.9) | 27.1 (4.2) | 24.56(5.9) | 38.9 (5.9) |
The ANOVA indicated that both major factors resin type (p<.001) and time after deposition (p <.001) had significant influences on resin wetting of dentin. Most QAM-blends showed better wettability compared to the NQC and comparable wettability to SBMP. Generally increasing the QAM concentration increased the wettability slightly over time but the difference was not significant p>0.05.
Conclusions: QAM-containing resin-blends are successful candidates for experimental adhesive resin blends.
Supported, in part, by grants R01DE015305 from the NIDCR (PI: DP) and by #8126472 from the Academy of Finland (PI: AT-M).
Keywords: Adhesion, Dentin and Dentin bonding agents
See more of: Dental Materials 1: Adhesion - Bond Strength Testing and Mechanisms