Beneficial effects of hydroxyapatite on enamel subjected to 30% hydrogen peroxide

Jiang, Tao; Ma, Xiao; Wang, Zhejun; Tong, Hua; Hu, Jiming; Wang, Yining

doi:10.1016/j.jdent.2008.07.005

« Previous Next »Journal of Dentistry
Volume 36, Issue 11 , Pages 907-914, November 2008

Beneficial effects of hydroxyapatite on enamel subjected to 30% hydrogen peroxide

Tao Jiang
- Key Laboratory for Oral Biomedical Engineering, Ministry of Education, School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan 430079, PR China
- Institute of Analytical and Biomedical Science, Wuhan University, Luojia Hill, Wuhan 430072, PR China
- Contributed equally to this work.
Xiao Ma
- Key Laboratory for Oral Biomedical Engineering, Ministry of Education, School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan 430079, PR China
- Contributed equally to this work.
Zhejun Wang
- Key Laboratory for Oral Biomedical Engineering, Ministry of Education, School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan 430079, PR China
Hua Tong
- Institute of Analytical and Biomedical Science, Wuhan University, Luojia Hill, Wuhan 430072, PR China
Jiming Hu
- Institute of Analytical and Biomedical Science, Wuhan University, Luojia Hill, Wuhan 430072, PR China
Yining Wang
- Key Laboratory for Oral Biomedical Engineering, Ministry of Education, School and Hospital of Stomatology, Wuhan University, 237 Luoyu Road, Wuhan 430079, PR China
- Corresponding author. Tel.: +86 27 87646696; fax: +86 27 87873260.

Received 8 April 2008; received in revised form 14 July 2008; accepted 20 July 2008.

Abstract

Objectives

To evaluate the effect of combination of hydroxyapatite (HA) and hydrogen peroxide (HP) on color, microhardness and morphology of human tooth enamel.

Methods

Forty-eight human dental blocks were obtained from 12 pairs of premolars and were randomly divided into four groups. Group DW was treated with distilled water, group HP with 30% HP, group HA+DW with HA mixed with distilled water and group HA+HP with HA mixed with 30% HP. Baseline and final color measurements and microhardness test were carried out before and after bleaching experiments. Two specimens from each group were selected for morphological investigation after final tests.

Results

The ΔE of group HP and HA+HP were significantly higher than those of group DW (p=0.000 and p=0.000) and group HA+DW (p=0.000 and p=0.000). The percentage microhardness loss of group HA+HP was significantly lower than that of group HP (p=0.047), but significantly higher than those of group DW (p=0.000) and group HA+DW (p=0.000). The obvious variation of morphology was only observed on enamel surfaces in group HP.

Conclusions

This study suggested that combination of HA and HP was effective in tooth whitening. HA could significantly reduce the microhardness loss of enamel caused by 30% HP and keep enamel surface morphology almost unchanged.

Keywords: Hydroxyapatite, Hydrogen peroxide, Enamel, Tooth bleaching