title: Effect of Nd:YAG laser irradiation and fluoride application in the progression of dentin erosion in vitro.
abstract: Nd:YAG laser and its association with fluoride have been proposed as an option for the prevention of dental erosion. This study evaluated the progression of existing dentin erosive lesions after treatment with different Nd:YAG laser (1064 nm) protocols, associated or not with fluoride. Erosive lesions were created with 1 % citric acid for 10 min in human dentin specimens. They were randomly assigned into eight groups (n = 15): no treatment (control), 1-min application of 2 % sodium fluoride gel (NaF), Nd:YAG1 (Nd:YAG laser irradiation 0.5 W; 50 mJ; ~41.66 J/cm(2); 10 Hz; 40 s; in contact), Nd:YAG2 (0.7 W; 70 mJ; ~62.50 J/cm(2); 10 Hz; 40 s; in contact), Nd:YAG3 (1 W; 100 mJ; ~54,16 J/cm(2); 10 Hz; 40 s; 1 mm unfocused), NaF + Nd:YAG1, NaF + Nd:YAG2, and NaF + Nd:YAG3. After treatment, the specimens were submitted to a 5-day erosion-remineralization cycling model, 6×/day. Dentin surface loss (SL) was evaluated with optical profilometry after the formation of the initial lesion; after treatment; and after days 1, 3, and 5. Data were statistically analyzed (alpha = 0.05). Significant differences were observed among the groups in all testing times (p < 0.001), except after initial lesion formation. Loss of dentin surface was observed after irradiation with all Nd:YAG laser protocols (p < 0.05). The association fluoride and laser did not differ significantly from laser alone. NaF showed the lowest values of SL and Nd:YAG2 and NaF + Nd:YAG2, the highest. Within the limitations of an in vitro study, it was concluded that laser irradiation, according to the parameters used, was not an appropriated approach to prevent dentin erosion progression, even when it was associated with fluoride.
authors.affiliation: Special Laboratory of Lasers in Dentistry (LELO), Department of Restorative Dentistry, School of Dentistry, University of São Paulo (USP), Av. Prof. Lineu Prestes, 2227, 05508-000, São Paulo, SP, Brazil.
authors.forename: Samira Helena
authors.initials: SH
authors.lastname: João-Souza
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, University of São Paulo (USP), Av. Prof. Lineu Prestes, 2227, 05508-000, São Paulo, SP, Brazil.
authors.forename: Tais
authors.initials: T
authors.lastname: Scaramucci
authors.affiliation: Oral Health Research Institute, Department of Preventive and Community Dentistry, Indiana University School of Dentistry, Indianapolis, IN, USA.
authors.forename: Anderson T
authors.initials: AT
authors.lastname: Hara
authors.affiliation: Special Laboratory of Lasers in Dentistry (LELO), Department of Restorative Dentistry, School of Dentistry, University of São Paulo (USP), Av. Prof. Lineu Prestes, 2227, 05508-000, São Paulo, SP, Brazil. acca@usp.br.
authors.forename: Ana Cecilia Corrêa
authors.initials: AC
authors.lastname: Aranha
mesh_terms: D003804:Dentin / Q000187:drug effects* / Q000528:radiation effects*; D006801:Humans; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D008963:Molar / Q000187:drug effects / Q000528:radiation effects; D012969:Sodium Fluoride / Q000494:pharmacology* / Q000627:therapeutic use; D014077:Tooth Erosion / Q000188:drug therapy* / Q000517:prevention & control / Q000532:radiotherapy*
chemical_list: D012969:Sodium Fluoride
keywords: Dentin erosion; Fluoride; Laser; Optical profilometry