Effect of wear resistance improvement of Nano-filled resin coating

Objective: Recently, resin-coating materials were commonly used for the simple and convenience. But then, there was a problem that it wore and lost the gloss easily. It is because the ingredient consists of only a resin. So we adopted "Nano-filler technology" to solve the problem and succeeded in improving the wear resistance of the coating surface. The purpose of this study was to evaluate the effect of wear resistance of Nano-filled resin coating materials by toothbrush brushing. 

Methods: Two different types of coating agents, Nano-filled light cured resin coating [Optiglaze, OG (GC)] and unfilled light cured resin coating [Permalink, PL (GC)] was examined. The specimens of 15.0mm diameter and 1.5mm thick disks were prepared with micro-fine hybrid indirect resin composite [Prossimo, PS (GC)]. Their surfaces were polished with wet silicon carbide paper (#600), then each coating agents were coated. Non-coating control specimens were polished with buff. All specimens were stored in water for 1 day at 37-degrees Celsius. Specimens prepared were tested using the abrasion tester under the following test conditions.

	Test conditions
Reciprocating motion	50,000 times (200 times/minutes)
Amplitude range	50 mm
Load	1080 g

The surface glosses before and after the abrasion testwere measured with gloss meter (VG2000, NIPPON DENSHOKU). The data were analyzed by one-way ANOVA and Fisher's LSD test (p<0.01).

Results:

	Control [Uncoated]	Surface with PL [Unfilled coating]	Surface with OG [Nano-filled coating]
Gloss % (Before)	81.6[0.3]	86.8[0.2]	87.6[0.2]
Gloss % (After 50,000 cycles)	46.8[4.7]	32.7[3.2]	62.2[0.9]

[SD]; n=5

OG coated surface keeps gloss after test significantly. (p<0.01).

Conclusion: These results suggested that Nano-filled resin coating (OG) gives high wear resistance and long-lasting gloss compared with unfilled resin coating.