title: The effect of argon laser irradiation on demineralization resistance of human enamel adjacent to orthodontic brackets: an in vitro study.
abstract: Argon lasers, because of their significant timesavings over conventional curing lights, have been investigated for use in bonding orthodontic brackets. They are also being investigated for their ability to confer demineralization resistance on enamel, which is of great interest in orthodontics. A two-part in vitro study on 86 human posterior teeth was conducted to determine the effects of a five-second argon laser exposure on shear bond strength and to evaluate the effects of a five- and 10-second argon laser exposure (250 mW) on demineralization of enamel surrounding orthodontic brackets after exposure to an artificial caries bath. Brackets cured with the argon laser for five seconds yielded mean bond strengths similar to those attained with a 40-second conventional light-cured control (n = 13 per group, 20.4 vs 17.8 MPa). Brackets cured with the argon laser for 10 seconds resulted in significantly lower mean lesion depth when compared with a visible light control (n = 20 per group, 107.8 vs 137.2 microm, P = .038). There were no statistically significant differences in lesion depth between the five-second argon laser and the visible light control groups. Overall, there was a 15% and 22% reduction in lesion depths for the five- and 10-second group, respectively. Poor correlations were found between the clinical appearance of decalcifications and their lesion depth. Argon lasers used for bonding orthodontic brackets would save a significant amount of chair time while possibly conferring demineralization resistance upon the enamel.
authors.affiliation: Mayo Clinic, Department of Dental Specialties, Division of Orthodontics, Rochester, MN 55905, USA.
authors.forename: Lloyd
authors.initials: L
authors.lastname: Noel
authors.forename: Joe
authors.initials: J
authors.lastname: Rebellato
authors.forename: Rose D
authors.initials: RD
authors.lastname: Sheats
mesh_terms: D000085:Acetates; D000134:Acid Etching, Dental; D000180:Acrylic Resins / Q000737:chemistry; D000704:Analysis of Variance; D001128:Argon; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D001840:Dental Bonding / Q000379:methods; D003743:Dental Enamel / Q000528:radiation effects*; D006801:Humans; D053685:Laser Therapy; D008027:Light; D016910:Orthodontic Brackets; D011829:Radiation Dosage; D019279:Resin Cements / Q000737:chemistry; D018709:Statistics, Nonparametric; D013314:Stress, Mechanical; D013997:Time Factors; D017001:Tooth Demineralization / Q000517:prevention & control*
chemical_list: D000085:Acetates; D000180:Acrylic Resins; D019279:Resin Cements; C065742:Transbond; D017438:Bisphenol A-Glycidyl Methacrylate; D001128:Argon