Influence of surface treatments on enamel susceptibility to staining by cigarette smoke.
OBJECTIVE
The purpose of this study was to evaluate the influence of remineralizing agents, including artificial saliva, neutral fluoride, and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP), on the susceptibility of bleached enamel to staining by cigarette smoke.


METHODS
Fifty bovine enamel blocks were randomly divided into five groups (n = 10): G1- bleaching; G2- bleaching and immersion in artificial saliva; G3- bleaching and application of CPP-ACP; G4- bleaching and application of neutral fluoride; and G5- untreated (Control). Teeth were bleached with 35% hydrogen peroxide and treated with the appropriate remineralizing agent. After treatment, all groups were exposed to cigarette smoke. Enamel color measurements were performed at three different times: before treatment (T1), after treatment (bleaching and remineralizing agent) (T2), and after staining (T3), by using the CIE Lab method with a spectrophotometer. The data coordinate L* was evaluated by analysis of repeated-measures PROC MIXED and Tukey-Kramer's test, and the ΔE values were submitted to one-way ANOVA and Tukey's test (α = 0.05).


RESULTS
The G1 group did not show any statistically significant difference for L* values between times T1 and T2. The G4 and G5 groups showed lower L* values at T3 compared to T2. No significant differences between the groups were observed for ΔE (after treatment and staining). However, G4 showed a clinically apparent color change.


CONCLUSIONS
Treatment of bleached enamel with neutral fluoride can contribute to the increased staining of enamel due to cigarette smoke. Key words:Spectrophotometer, remineralizing agents, bleaching.
DDS, MS student. Department of Restorative Dentistry, Piracicaba Dental School, Campinas University - UNICAMP, SP, Brazil.
Juliana C
JC
Públio
DDS, MS, PhD student. Department of Restorative Dentistry, Piracicaba Dental School, Campinas University - UNICAMP, SP, Brazil.
Maria Bf
MB
D'Arce
DDS. Department of Restorative Dentistry, Piracicaba Dental School, Campinas University - UNICAMP, SP, Brazil.
Nádia M
NM
Brunharo
PhD, Full Professor. Department of Social Dentistry/Statistics, Piracicaba Dental School, Campinas University - UNICAMP, SP, Brazil.
Gláucia Mb
GM
Ambrosano
DDS, MS, PhD, Assistant Professor. Department of Restorative Dentistry, Piracicaba Dental School, Campinas University - UNICAMP, SP, Brazil.
Flávio Hb
FH
Aguiar
DDS, MS, PhD, Full Professor. Department of Restorative Dentistry, Piracicaba Dental School, Campinas University -UNICAMP, SP, Brazil.
José R
JR
Lovadino
DDS, MS, PhD, Assistant Professor. Department of Restorative Dentistry, Piracicaba Dental School, Campinas University - UNICAMP, SP, Brazil.
Débora Anl
DA
Lima