Methods: Bis-GMA/TEGDMA/UDMA (equal mass ratios) was mixed with camphorquinone (0.5wt%), dimethylaminoethyl methacrylate (0.25wt%), and butylhydroxytoluene (0.5wt%). 70wt% silanated filler was added. For SAMs, a central hole (diameter=0.5mm, 0.4mm, or 0.25 mm) was fabricated in aluminum discs (thickness=0.4mm). To evaluate CFPs, Teflon® molds (n=5/method; h=6mm x ID=6mm) were filled and polymerized by: 1) 10s with 0.5mm mask, 2) 10s with 0.4mm mask, or 3) 10s with 0.25mm mask. Unpolymerized MRC was removed with acetone, remaining cured MRC dried, then cured “bullet” diameter and depth/height measured. For DC, specimens were similarly created. Polymerization was by: 1) 60s no mask, 2) 10s, 0.5mm mask+50s no mask, 3) 10s, 0.4mm mask+50s no mask, or 4) 10s, 0.25mm mask+50s no mask. DC was measured by FTIR. Results were statistically analyzed (One-Way ANOVA, Student-Newman-Keuls, α=0.05).
Results: Based on the apparent dome-shape of the cured “bullets”, an ellipsoid dome formula was selected to model CFPs. Equations were derived and plotted for each polymerization method utilizing the average measured diameters and depths/heights.
Aperture Size (mm) |
Time With/Without Mask (s) |
Diameter (mm) |
Depth (mm) |
Top DC (%) |
Bottom DC (%) |
B/T Ratio (%) |
NONE |
0/60 |
- |
- |
79.89±2.98a |
72.45±2.16a |
90.84±5.25a |
0.5 |
10/50 |
2.119±0.113a |
1.243±0.080a |
68.46±3.70b |
65.61±3.10b |
95.89±2.07a,b |
0.4 |
10/50 |
1.685±0.035b |
0.940±0.032b |
73.24±2.36c |
72.56±2.77a |
99.10±3.00b |
0.25 |
10/50 |
0.987±0.048c |
0.553±0.017c |
75.58±1.86c |
73.73±2.76a |
97.65±5.69a,b |
Conclusions: Initial experiments show utilization of a 0.4mm SAM for the first 10s significantly increases the B/T DC. The effect of a SAM on additional curing properties of dental composites will be further investigated.