Effect of whitening dentifrices on the surface roughness of a nanohybrid composite resin.
OBJECTIVE
The present study verified the influence of whitening dentifrices on the surface roughness of a nanohybrid composite resin.


METHODS
Thirty-two specimens were prepared with Filtek™ Z350 XT (3M/ESPE) and randomly divided into four groups (n = 08) that were subjected to brushing simulation equivalent to the period of 1 month. The groups assessed were a control group with distilled water (G1), Colgate Total 12 Professional Clean (G2), Sensodyne Extra Whitener Extra Fresh (G3), and Colgate Luminous White (G4). A sequence of 90 cycles was performed for all the samples. The initial roughness of each group was analyzed by the Surface Roughness Tester (TR 200-TIME Group Inc., CA, USA). After the brushing period, the final roughness was measured, and the results were statistically analyzed using nonparametric Kruskal-Wallis and Dunn tests for intergroup roughness comparison in the time factor. For intragroup and "Δ Final - Initial" comparisons, the Wilcoxon test and (one-way) ANOVA were, respectively, performed (α = 0.05).


RESULTS
The roughness mean values before and after brushing showed no statistically significant difference when the different dentifrices were used. None of the dentifrices analyzed increased significantly the nanohybrid composite resin surface roughness in a 1 month of tooth brushing simulation.


CONCLUSIONS
These results suggest that no hazardous effect on the roughness of nanohybrid composite resin can be expected when whitening dentifrices are used for a short period. Similar studies should be conducted to analyze other esthetic composite materials.
Department of Operative Dentistry, School of Health Sciences, State University of Amazonas, UEA, Manaus, Brazil.
Gabriela Migliorin
GM
da Rosa
Department of Operative Dentistry, Postgraduate Program in Dentistry, Faculty of Dentistry, Federal University of Amazonas, UFAM, Manaus, Brazil.
Luciana Mendonça
LM
da Silva
Department of Operative Dentistry, School of Health Sciences, State University of Amazonas, UEA, Manaus, Brazil.
Márcio
M
de Menezes
Department of Periodontology, School of Health Sciences, State University of Amazonas, UEA, Manaus, Brazil.
Hugo Felipe
HF
do Vale
Department of Operative Dentistry, School of Health Sciences, State University of Amazonas, UEA, Manaus, Brazil.
Diego Ferreira
DF
Regalado
Department of Operative Dentistry, School of Health Sciences, State University of Amazonas, UEA, Manaus, Brazil.|Department of Operative Dentistry, Postgraduate Program in Dentistry, Faculty of Dentistry, Federal University of Amazonas, UFAM, Manaus, Brazil.
Danielson Guedes
DG
Pontes
Composite resin; roughness; tooth brushing; whitening dentifrices