The effect of CO2 9.3 mu m short-pulsed laser irradiation in enamel erosion reduction with and without fluoride applications-a randomized, controlled in vitro study

Author(s)

Silva, V, C. ; Mantilla, T. F. ^[1] ; Engel, Y. ^[1] ; Tavares, J. P. ^[1] ; Freitas, P. M. ^[1] ; Rechmann, P. ^[2]

Affiliation

^[1] Silva, C., V, Univ Sao Paulo, Fac Odontol, Dept Restorat Dent, Av Prof Lineu Prestes 2227, Cidade Univ, BR-05508000 Sao Paulo, SP - Brazil

^[2] Univ Calif San Francisco, Sch Dent, Dept Prevent & Restorat Dent Sci, 707 Parnassus Ave, San Francisco, CA 94143 - USA

• Document type: Journal article
• Source: Lasers in Medical Science; v. 35, n. 5 FEB 2020.
• Web of Science Citations: 0

Abstract

The aim of this in vitro study was to evaluate the protective effect of short-pulsed CO2 9.3 mu m laser irradiation against erosion in human enamel without and combined with TiF4 and AmF/NaF/SnCl2 applications, respectively, as well as compared to the protective effect of these fluoride treatments alone. After polishing, ninety enamel samples (3 x 3mm) were used for 9 different treatment groups: 4% TiF4 gel (pH 1.5, 24,533 ppm F-); AmF/NaF/SnCl2 rinse (pH 4.5; 500 ppm F-, 800 ppm Sn-2); CO2 laser (average power 0.58 W); CO2 laser (0.58 W) + TiF4; CO2 laser (0.58 W) + AmF/NaF/SnCl2; CO2 laser (0.69 W); CO2 laser (0.69 W) + TiF4; CO2 laser (0.69 W) + AmF/NaF/SnCl2; negative control (deionized water). TiF4 gel was brushed on only once before the first erosive cycling, while samples treated with AmF/NaF/SnCl2 were daily immersed in 5 ml of the solution before cycling. Laser treatment occurred with a CO2 laser (wavelength 9.3 mu m, pulse repetition rate 100 Hz, pulse duration 14.6 mu s/18 mu s, average power 0.58 W/0.69 W, fluence 1.9 J/cm(2)/2.2 J/cm(2), beam diameter 0.63 mm, irradiation time 10 s, air cooling). TiF4 was applied only once, while AmF/NaF/SnCl2 was applied once daily before the erosive challenge. Surface loss (in mu m) was measured with optical profilometry immediately after treatment, and after 5 and 10 days of erosive cycling (0.5% citric acid, pH 2.3, 6 x 2 min/day). Additionally, scanning electron microscopy investigations were performed. All application measures resulted in loss of surface height immediately after treatment. After 5 days, significantly reduced surface loss was observed after applying laser irradiation (both power settings) followed by applications of TiF4 or AmF/NaF/SnCl2 solution (p < 0.05; 2-way ANOVA and Tukey test) compared to fluoride application alone. After 10 days, compared to after 5 days, a reduced tissue loss was observed in all groups treated with AmF/NaF/SnCl2 solution. This tissue gain occurred with the AmF/NaF/SnCl2 application alone and was significantly higher when the application was combined with the laser use (p < 0.05). Short-pulsed CO2 9.3 mu m laser irradiation followed by additional application of AmF/NaF/SnCl2 solution significantly reduces the progression of dental enamel erosion in vitro. (AU)

• FAPESP's process: 15/10248-5 - Evaluation of the TiF4 gel protector effect on eroded human dentin: an in situ study
• Grantee: Patricia Moreira de Freitas Costa e Silva
• Support Opportunities: Regular Research Grants
• FAPESP's process: 16/08524-7 - Influence of adquired pellicle and timing of application of the AmF/NaF/SnCl2 solution on its potential to control the progression of human enamel erosion.
• Grantee: Camila Vieira da Silva
• Support Opportunities: Scholarships in Brazil - Doctorate