The first aim of this study was to compare the effect of different curing lights on the degree of conversion of three modern dental bonding adhesives. The second aim was to investigate the effect of oxygen inhibition (anaerobic effect) on the outermost layer of these adhesives.
Methods:
This study compares the effects of quartz-tungsten-halogen (QTH) light curing versus light-emitting diode (LED) curing of three dentin bonding adhesives: OptiBond All in One (OAIO), Adper Easy Bond (AEB) and ExciteF (EXF). It also observes the influence that the surface oxygen layer has on the curing of dentin bonding adhesives. Removal of the oxygen-inhibited layer was accomplished using a mylar plastic strip (Hawe Striproll No. 686 8mm/15m) pushed onto each bonding adhesive. The plastic strip remained on top of the bonding adhesive until light curing was complete. Samples were cured in four different ways: (1) QTH, (2) LED, (3) QTH + strip (for the oxygen inhibited layer displaced), (4) LED + strip. The degree of conversion (DC) of each sample was calculated utilizing the Fourier transform infrared spectroscopy (FTIR) (Thermo Scientific Nicolet™ 6700), with C=C (1640cm-1) and C-C (1610cm-1) ratio between polymerized and unpolymerized samples (n=3). The data was analyzed statistically by two-way ANOVA, and Fisher Test (p <0.05).
Results:
Table below reports the average percent (DC) and the standard deviations.
|
QTH |
QTH + Strip |
LED |
LED + Strip |
OAIO |
39.8 ± 1.4 |
45.8 ± 2.5 |
43.1 ±1.2 |
47.8 ± 0.9 |
AEB |
33.8 ± 1.8 |
40 ± 1.1 |
36.7 ±0.4 |
45.1 ± 3.1 |
EXF |
21.4 ± 1.7 |
38.6 ± 2 |
24.6 ± 1.1 |
42.1 ± 2 |
Conclusions:
Light curing device, brand of adhesive, and the interaction between them are significantly different (p<0.05). Displacing the oxygen present on the surface with the mylar strip was significantly different for all adhesives.