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Effects of Low-energy CO2 Laser Irradiation and the Organic Matrix on Inhibition of Enamel Demineralization

Department of Preventive Dentistry, Faculty of Dentistry, National University of Singapore, Singapore 119074

T.H. Jordan

Department of Chemistry, Cornell College, Mount Vernon, IA 52314, USA

D.N. Dederich

Department of Periodontics, LSUMC School of Dentistry, New Orleans, LA 70019, USA

J.S. Wefel

Dows Institute for Dental Research, College of Dentistry, University of Iowa, Iowa City, IA 52242, USA

In the past two decades, accumulated evidence has clearly demonstrated the inhibitory effects of laser irradiation on enamel demineralization, but the exact mechanisms of these effects remain unclear. The purpose of this study was to investigate the effects of low-energy CO2 laser irradiation on demineralization of both normal human enamel and human enamel with its organic matrix removed. Twenty-four human molars were collected, cleaned, and cut into two halves. One half of each tooth was randomly selected and its lipid and protein content extracted. The other half of each tooth was used as the matched control. Each tooth half had two window areas. All the left windows were treated with a low-energy laser irradiation, whereas the right windows served as the non-laser controls. After caries-like lesion formation in a pH-cycling environment, microradiographs of tooth sections were taken for quantification of demineralization. The mean mineral losses (with standard deviation) of the enamel control, the lased enamel, the non-organic enamel control, and the lased non-organic enamel subgroups were 3955 (1191), 52(49), 4565(1311), and 1191 (940), respectively. A factorial ANOVA showed significant effects of laser irradiation (p = 0.0001), organic matrix (p - 0.0125), and the laser-organic matrix interaction (p = 0.0377). The laser irradiation resulted in a greater than 98% reduction in mineral loss, but the laser effect dropped to about 70% when the organic matrix in the enamel was removed. The results suggest that clinically applicable CO₂ laser irradiation may cause an almost complete inhibition of enamel demineralization.

Key Words: CO2 laser • organic matrix • enamel demineralization.

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Journal of Dental Research, Vol. 79, No. 9, 1725-1730 (2000)
DOI: 10.1177/00220345000790091401


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This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Hsu, C.-Y.S. Articles by Wefel, J.S. Search for Related Content PubMed PubMed Citation Articles by Hsu, C.-Y.S. Articles by Wefel, J.S. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Hazardous Substances DB CARBON DIOXIDE Social Bookmarking                         What's this?