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Updated: Feb 14, 2026

Sampling and Pretreatment of Tooth Enamel Carbonate for Stable Carbon and Oxygen Isotope Analysis
Published on: August 15, 2018
A comparative evaluation of APF gel, CPP/ACP paste alone and in combination with carbon dioxide laser on human enamel
Ali Nozari1, Azade Rafiee2,3, Sara Dehghan Khalili4
1Department of Pediatric Dentistry, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
Background:
The aim of this study was to compare the effects of acidulated phosphate fluoride (APF) gel, calcium phosphopeptide-amorphous calcium phosphate (CPP/ACP) paste alone and in combination with CO2 laser on the resistance of enamel to acid solubility.
Methods:
Ninety enamel sections were obtained from 15 extracted teeth and were randomly assigned to six groups: 1) control group; 2) APF group; 3) CPP-ACP group; 4) CO2 laser group; 5) APF + CO2 group; and 6) CPP-ACP + CO2 group. The specimens were individually demineralized in 0.1 M lactic acid solution with adjusted pH of 4.8 for 24h at 37 ºC. The acid solubility was determined using atomic absorption spectrometry. Statistical analysis was done using one-way ANOVA and Tukey-Kramer post hoc test (P<0.05).
Results:
The average extent of calcium ion released (ppm) was estimated as follow: group 1: 6.974±1.757, group 2: 5.363±1.383, group 3: 6.962±1.489, group 4: 6.890±1.560, group 5: 4.803±1.080 and group 6: 6.789±1.218. Based on the between-group comparison results, group 2 and group 5 showed significant differences with the other groups.
Conclusions:
Under the studied conditions, only, the APF group alone and in combination with CO2 laser could decrease enamel acid solubility.
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