Rp. Pagniano et Wm. Johnston, THE EFFECT OF UNFILLED RESIN DILUTION ON COMPOSITE RESIN HARDNESS ANDABRASION RESISTANCE, The Journal of prosthetic dentistry, 70(3), 1993, pp. 214-218
Diluting composite materials with unfilled resin to facilitate clinica
l application during direct lamination will result in an alteration of
filler loading with possible changes of physical properties. This stu
dy compared the surface hardness and abrasion resistance of a visible
light-cured microfilled and hybrid resin with and without dilution. Sa
mples were prepared, cured, and stored in distilled water at 37-degree
s C for 24 hours before testing. Knoop hardness values were obtained f
rom the upper surface of 10 samples in three dilution and control grou
ps of each material. Three samples of the dilution and control groups
were similarly prepared and stored for toothbrush abrasion testing. Da
ta from the hardness and abrasion tests were subjected to analysis of
variance and Tukey's test at a 0.05 level of significance. Results sho
wed that dilution had a significant eff ect on surface hardness of the
materials tested, although the diluted materials were not significant
ly different from the controls. Abrasion tests showed visible evidence
of abrasion on all samples, but dilution showed no significant effect
on abrasion resistance of the materials tested.