IADR Abstract Archives
New Antimicrobial Macromers for Dental Self-Etch Adhesives
Antimicrobial adhesives help to eliminate remaining bacteria after minimally invasive therapy. This pilot-study investigates trialkylammonium-oligo(oxazoline)-methacrylamides M2a and M2b of varying spacer-length as antimicrobial macromers in the two-component self-etching adhesive AdheSE®. Macromer M2a (n=23; M=1914 M2b (n=55; M=3705 g/mol)
Methods:
Four experiments were conducted using the following formulations.
| Exp.1 : Antimicrobial Activity | |
| Experimental | Control |
| AdheSE®Primer+2.5wt.-%M2b (AP-2.5b) | AdheSE®Primer (AP) |
| AdheSE®Primer+5wt.-%M2b (AP-5b) | AdheSE®Primer (AP) |
| AdheSE®Bond+2.5wt.-%M2b (AB-2.5b) | AdheSE®Bond (AB) |
| AdheSE®Bond+5wt.-%M2b (AB-5b) | AdheSE®Bond (AB) |
| Exp.2 : Storage-Stability (42°C) | |
| AP-2.5a | AP+AB |
| AP-2.5b | AP+AB |
| Exp.3 : Comparison of antimicrobial activities | |
| AB-5b | AB |
| AB+5wt.-% MDPB (AB-M) | AB |
| AB+5wt.-% Q-DAPMAA (AB-Q) | AB |
| Exp.4 : Leaching-Resistance | |
| GDMA+HEMA+M2a (22.3+77+3.7 wt-%)(GH-a) | not applicable |
| GDMA+HEMA+MDPB (22.3+77+3.7 wt-%)(GH-M) | not applicable |
Exp.1) Each combination of experimental versus control formulation was applied onto one glass slide, spray-inoculated with S.mutans (ATCC, strain 25175), incubated under agar (24h/37°C) and stained with 2,3,5-triphenyltetrazoliumchloride to determine colony-forming-units (CFU).
Exp.2) Shear-bond-strength (SBS) (ISO/TS-11409, n=5) of AP-2.5a and AP-2.5b stored at 42°C to bovine dentin was determined using AB and Tetric EvoFlow composite.
Exp.3) Activity of AB-5b against S.aureus (ATCC, strain 25923) was compared to that of N-pyridinium-10-hydroxydecyl-methacrylate (MDPB) in AB-M or N-dodecyl-N,N-dimethyl-N'-(3-propylammonium)-methacrylamide (Q-DAPMAA) in AB-Q.
Exp.4) A glass slide coated with GH-a or GH-M was washed with phosphate buffer at 25°C for 4 and 7 days and activity against S.mutans determined as in experiment 1.
Results:
| Exp.1 | |||
| sample | CFUxcm-2 | control | CFUxcm-2 |
| AP-2.5b | 6 | AP | 35 |
| AP-5b | 0 | AP | 58 |
| AB-2.5b | 6 | AB | 74 |
| AB-5b | 4 | AB | 75 |
| Exp.2 | |||
| weeks@42°C | SBS [MPa] | ||
| AP-2.5a | AP-2.5b | AP+AB | |
| 0 | 18.4±1.7 | 19.3±1.9 | 19.4±4 |
| 4 | 17.3±4.3 | 22.4±4.5 | 21.2±4 |
| 8 | 18.8±1.5 | 19.0±2.4 | 19.9±1.8 |
| Exp.3 | |||
| sample | CFUxcm-2 | control | CFUxcm-2 |
| AB-5b | 0 | AB | >>100 |
| AB-M | 33 | AB | 76 |
| AB-Q | >>100 | AB | >>100 |
| Exp.4 | |||
| days of washing | CFUxcm-2 | ||
| GH-a | GH-M | ||
| 4 | 0 | >>100 | |
| 7 | 0 | >>100 | |
Conclusions:
In-vitro experiments with trialkylammonium-oligo(oxazoline)-methyacrylamides showed M2a and M2b's applicability as potent antimicrobial agents in self-etching adhesive formulations.