This study aimed at analyzing the
compomers wear by an "in vitro"
toothbrushing abrasion test. The null hypotheses tested were that there would be no differences in
weight loss and no significant changes in surface roughness of the
compomers after this test. The utilized commercial brands were
Dyract (
Dentsply),
Dyract AP (
Dentsply),
Compoglass F (
Vivadent), Freedom (SDI), F2000 (3M ESPE), which were compared to the two resin composites Z100 (3M ESPE) and
Silux Plus (3M ESPE). Ten cylindrical specimens for each commercial brand were prepared with 5mm diameter and 3mm thickness. An appropriate machine with soft bristle
tips containing
dentifrice solution and deionized water was used. A total of 100,000 brushing cycles were performed. The amount of
weight loss was measured by the percentage alteration between the initial (before
toothbrushing) and final weight (after
toothbrushing), measured by a Sartorius analytical balance. The surface roughness change was determined by the percentage difference between initial and final means after 5 tracings by a T 1000 Hommel Tester roughness meter on the specimen's surfaces before and after
toothbrushing abrasion test. The statistical analysis (Students paired t-test, ANOVA and Tukey, á=0.05) showed that all materials presented statistically significant
weight loss and roughness increase after abrasion test. All
compomers presented higher
weight loss than resin composites. Freedom and
Dyract AP presented the lowest
weight loss among
compomers. F2000 presented the worst abrasion resistance, without statistical differences with
Dyract. For roughness changes,
Dyract,
Dyract AP, Z100,
Compoglass F and
Silux Plus showed the lowest surface roughness alteration, in increasing order, without statistical differences between them. Freedom was the statistically roughest material of the study.