过氧化氢浓度对牙釉质颜色和显微硬度的影响。

Effect of hydrogen peroxide concentration on enamel color and microhardness.

作者信息

Borges A B, Zanatta R F, Barros A C S M, Silva L C, Pucci C R, Torres C R G

出版信息

Oper Dent. 2015 Jan-Feb;40(1):96-101. doi: 10.2341/13-371-L. Epub 2014 Aug 19.

DOI:10.2341/13-371-L

PMID:25136902

Abstract

OBJECTIVES

The aim of this study was to investigate the effect of hydrogen peroxide gels with different concentrations (20%, 25%, 30%, and 35%) on enamel Knoop microhardness (KNH) as well as on changes in dental color (C).

METHODS

Cylindrical specimens of enamel/dentin (3-mm diameter and 2-mm thickness) were obtained from bovine incisors and randomly divided into six groups (n=20), according to the concentration of the whitening gel (20%, 25%, 30%, 35%, control, thickener). After polishing, initial values of KNH0 and color measurement, assessed by spectrophotometry using the CIE Lab* system, were taken from the enamel surface. The gels were applied on the enamel surface for 30 minutes, and immediate values of KNHi were taken. After seven days of being stored in artificial saliva, new measures of KNH7 and color (L7* a7* b7*, for calculating ΔE, ΔL, and Δb) were made. Data were submitted to statistical analysis of variance, followed by Tukey test (p<0.05).

RESULTS

Differences in gel concentration and time did not influence the microhardness (p=0.54 and p=0.29, respectively). In relation to color changes, ΔE data showed that the 35% gel presented a higher color alteration than the 20% gel did (p=0.006).

CONCLUSION

Bleaching with 35% hydrogen peroxide gel was more effective than with the 20% gel, without promoting significant adverse effects on enamel surface microhardness.

摘要

目的

本研究旨在调查不同浓度（20%、25%、30%和35%）的过氧化氢凝胶对牙釉质努氏显微硬度（KNH）以及牙齿颜色变化（C）的影响。

方法

从牛的切牙获取牙釉质/牙本质圆柱形样本（直径3毫米，厚度2毫米），根据美白凝胶的浓度（20%、25%、30%、35%、对照、增稠剂）随机分为六组（n = 20）。抛光后，使用CIE Lab系统通过分光光度法从牙釉质表面获取KNH0的初始值和颜色测量值。将凝胶涂覆在牙釉质表面30分钟，获取KNHi的即时值。在人工唾液中储存七天后，对KNH7和颜色（L7 a7* b7*，用于计算ΔE、ΔL和Δb）进行新的测量。数据进行方差统计分析，随后进行Tukey检验（p < 0.05）。