title: In vitro evaluation of erbium, chromium:yttrium-scandium-gallium-garnet laser-treated enamel demineralization.
abstract: This study evaluated the effect of different parameters of erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser irradiation on enamel mineral loss in a simulated caries model. Forty-five enamel samples obtained from third molar teeth (3 mmx 3 mm) were randomly divided into five groups (n = 9): G1-Er,Cr:YSGG laser at 0.25 W, 20 Hz, 2.8 J/cm(2); G2-Er,Cr:YSGG laser at 0.50 W, 20 Hz, 5.7 J/cm(2); G3-Er,Cr:YSGG laser at 0.75 W, 20 Hz, 8.5 J/cm(2); G4-sodium fluoride (NaF) dentifrice (positive control); G5-no treatment (negative control). After irradiation, the samples were submitted to 2 weeks of pH cycling. After the acid challenge, the samples were assessed by cross-sectional microhardness at different depths from the enamel surface. Analysis of variance (ANOVA) and Student-Newman-Keuls tests were performed (alpha = 5%). The percentage of lesion inhibition for each group was: G1 37%; G2 38%; G3 64%, and G4 50.5%. Regarding the relative mineral loss values (micrometers x volume percent), groups G1 (1,392 +/- 522) and G2 (1,292 +/- 657) did not differ significantly from each other, but both had higher values than group G3 (753 +/- 287); the groups irradiated with Er,Cr:YSGG laser did not differ from group G4. Although the findings of the study revealed that Er,Cr:YSGG laser irradiation at 8.5 J/cm(2) can be an alternative for the enhancement of the enamel's resistance to acid, lower energy densities also produced a cariostatic potential comparable to the use of fluoride dentifrice.
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, University of São Paulo (USP), Prof. Lineu Prestes, 2227, Cidade Universitária, Butantã, São Paulo, SP 05508-900, Brazil.
authors.forename: Patrícia M
authors.initials: PM
authors.lastname: de Freitas
authors.forename: Marcia
authors.initials: M
authors.lastname: Rapozo-Hilo
authors.forename: Carlos de P
authors.initials: Cde P
authors.lastname: Eduardo
authors.forename: John D B
authors.initials: JD
authors.lastname: Featherstone
mesh_terms: D000143:Acids; D003731:Dental Caries / Q000517:prevention & control; D003743:Dental Enamel / Q000187:drug effects / Q000528:radiation effects*; D006245:Hardness Tests; D006801:Humans; D006863:Hydrogen-Ion Concentration; D066298:In Vitro Techniques; D053844:Lasers, Solid-State / Q000627:therapeutic use*; D012969:Sodium Fluoride / Q000494:pharmacology; D017001:Tooth Demineralization / Q000517:prevention & control*
chemical_list: D000143:Acids; D012969:Sodium Fluoride
references.citation: Lasers Med Sci. 2008 Apr;23(2):141-7
references.pmid: 17899311
references.citation: J Clin Laser Med Surg. 1999;17(4):155-9
references.pmid: 11199838
references.citation: J Clin Laser Med Surg. 2001 Jun;19(3):159-63
references.pmid: 11469308
references.citation: Caries Res. 2003 May-Jun;37(3):194-9
references.pmid: 12740543
references.citation: J Oral Rehabil. 1997 Aug;24(8):624-7
references.pmid: 9291257
references.citation: J Am Dent Assoc. 2000 Jun;131(6):777-85
references.pmid: 10860330
references.citation: Caries Res. 1982;16(3):201-10
references.pmid: 6953998
references.citation: Caries Res. 1983;17(5):385-91
references.pmid: 6577953
references.citation: J Am Dent Assoc. 2000 Jul;131(7):887-99
references.pmid: 10916327
references.citation: Photomed Laser Surg. 2004 Aug;22(4):312-7
references.pmid: 15345174
references.citation: J Clin Laser Med Surg. 2003 Aug;21(4):197-201
references.pmid: 13678456
references.citation: J Clin Laser Med Surg. 2000 Jun;18(3):139-43
references.pmid: 11799978
references.citation: J Dent Res. 1998 Jun;77(6):1397-403
references.pmid: 9649168
references.citation: J Am Dent Assoc. 1998 May;129(5):585-91
references.pmid: 9601171
references.citation: Lasers Surg Med. 1989;9(4):345-51
references.pmid: 2503667
references.citation: Lasers Surg Med. 2002;30(5):337-41
references.pmid: 12116325
references.citation: Lasers Surg Med. 2002;31(4):275-82
references.pmid: 12355574
references.citation: Lasers Med Sci. 2003;18(2):112-8
references.pmid: 12928822
references.citation: Am J Dent. 2003 Apr;16(2):91-5
references.pmid: 12797565
references.citation: Caries Res. 2003 Jan-Feb;37(1):34-7
references.pmid: 12566637
references.citation: Calcif Tissue Int. 1986 Apr;38(4):197-208
references.pmid: 3011230
references.citation: Caries Res. 1985;19(4):335-41
references.pmid: 3861255
references.citation: Pediatr Dent. 2000 Jul-Aug;22(4):269-77
references.pmid: 10969430
references.citation: J Am Dent Assoc. 1997 Aug;128(8):1099-106
references.pmid: 9260419
references.citation: Caries Res. 1987;21(6):502-12
references.pmid: 3479256
references.citation: Caries Res. 2005 Jan-Feb;39(1):65-70
references.pmid: 15591737
references.citation: Lasers Surg Med. 1989;9(4):338-44
references.pmid: 2761329
references.citation: J Dent Educ. 2001 Oct;65(10):1114-20
references.pmid: 11699987