Reza Fekrazad1, Ahmad Najafi2, Ramona Mahfar3, Mahshid Namdari4, Mohadese Azarsina2. 1. DDS, MSc, FLD, FICD; Associate professor of periodontology department, Dental Faculty-Laser Research Center in Medical Sciences, AJA University of Medical Sciences, Tehran, Iran. 2. DDS; Assistant Professor of Operative Dentistry, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 3. Dental Student; Department of Operative Dentistry, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran. 4. PhD; Assistant Professor of Biostatistics Department, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Abstract
BACKGROUND AND AIMS: The aim was comparison of enamel remineralization after application of APF, TiF4 and CO2 laser alone or in combination. MATERIALS AND METHODS: Enamel blocks were prepared from human third molars. The initial surface hardness was determined by Vicker's hardness tester. The samples underwent a demineralization regimen for 7 days to produce artificial initial caries. The hardness of enamel blocks with white spot lesions was measured, and the samples which had the mean hardness change of 65-90%, were selected, and randomly divided into 5 groups (N=15): G1: control; G2: APF 1.23%; G3: TiF4 4%; G4: TiF4 4% followed by CO2 laser (10.6 µm wavelength, 1 W peak power, 10 ms pulse duration, 500 ms repeat time, 0.2 mm beam spot size, 2 cm distance); G5: CO2 laser (same parameters) followed by TiF4 4%. Surface hardness recovery was measured after the treatments. Three samples in each group were observed under scanning electron microscope at ×1,000 magnification. Data were analyzed by repeated measure ANOVA and Bonferrouni tests. Significance level was set at 0.05. RESULTS: G2, G3, G4 indicated significant differences with control and G5 (p<0.05). Surface hardness in G5 was not significantly different from control (p=0.7) in enamel hardness test. There was not a significant difference between G2 & G3, G2 & G4, and G3 & G4 (p=1). The SEM results indicated globules of calcium fluoride on the surface in G2, and a smooth glaze-like surface layer in G3 and G4. In G5, some micro-cracks without any glaze-like layer were observed. CONCLUSIONS: APF, TiF4 and TiF4 before CO2 laser irradiation significantly increased the micro-hardness of initially demineralized enamel surfaces. CO2 laser irradiation before TiF4 application could not remineralize the white-spot lesions.
BACKGROUND AND AIMS: The aim was comparison of enamel remineralization after application of APF, TiF4 and CO2 laser alone or in combination. MATERIALS AND METHODS: Enamel blocks were prepared from human third molars. The initial surface hardness was determined by Vicker's hardness tester. The samples underwent a demineralization regimen for 7 days to produce artificial initial caries. The hardness of enamel blocks with white spot lesions was measured, and the samples which had the mean hardness change of 65-90%, were selected, and randomly divided into 5 groups (N=15): G1: control; G2: APF 1.23%; G3: TiF4 4%; G4: TiF4 4% followed by CO2 laser (10.6 µm wavelength, 1 W peak power, 10 ms pulse duration, 500 ms repeat time, 0.2 mm beam spot size, 2 cm distance); G5: CO2 laser (same parameters) followed by TiF4 4%. Surface hardness recovery was measured after the treatments. Three samples in each group were observed under scanning electron microscope at ×1,000 magnification. Data were analyzed by repeated measure ANOVA and Bonferrouni tests. Significance level was set at 0.05. RESULTS: G2, G3, G4 indicated significant differences with control and G5 (p<0.05). Surface hardness in G5 was not significantly different from control (p=0.7) in enamel hardness test. There was not a significant difference between G2 & G3, G2 & G4, and G3 & G4 (p=1). The SEM results indicated globules of calcium fluoride on the surface in G2, and a smooth glaze-like surface layer in G3 and G4. In G5, some micro-cracks without any glaze-like layer were observed. CONCLUSIONS: APF, TiF4 and TiF4 before CO2 laser irradiation significantly increased the micro-hardness of initially demineralized enamel surfaces. CO2 laser irradiation before TiF4 application could not remineralize the white-spot lesions.
Authors: Livia P Comar; Annette Wiegand; Bruna M Moron; Daniela Rios; Marília A R Buzalaf; Wolfgang Buchalla; Ana C Magalhães Journal: Eur J Oral Sci Date: 2012-06-25 Impact factor: 2.612