title: Effects of near infrared laser radiation associated with photoabsorbing cream in preventing white spot lesions around orthodontic brackets: an in vitro study.
abstract: OBJECTIVE
  The present study aims to investigate the effect of a low-power infrared laser on the inhibition of bovine enamel demineralization around orthodontic brackets.
  
  
  BACKGROUND
  Near infrared lasers have been suggested as alternative approaches because they may produce an increase in resistance to dental caries.
  
  
  METHODS
  Forty-eight blocks of enamel obtained from bovine incisor teeth were divided into six groups: Group 1 (control), without treatment; Group 2 (C), photoabsorbing cream; Group 3 (CF), photoabsorbing cream with fluoride; Group 4 (L), irradiation with low-level infrared laser (λ=830 nm) at an energy density of 4.47 J/cm2; Group 5 (L+C), photoabsorbing cream followed by low-level infrared laser irradiation; and Group 6 (L+CF), photoabsorbing cream with fluoride followed by low-level infrared laser irradiation. After these procedures, the enamel blocks received an assortment of orthodontic brackets and were then submitted to pH cycling to simulate a highly cariogenic challenge. The enamel surface demineralization around the orthodontic brackets, according to the different treatments, was quantified by fluorescence loss analysis by quantitative light-induced fluorescence (QLF). The fluorescence loss, expressed as ΔF (percentage of loss fluorescence), was statistically examined by analysis of variance and the Tukey test.
  
  
  RESULTS
  The control group (-10.48±2.85) was statistically similar to Group C (-14.52±7.80), which presented the lowest values of ΔF when compared with Groups FC (-3.67±3.21), L (-2.79±1.68), CL (-1.05±0:50), and CFL (-0.60±0:43). However, Groups FC, L, CL, and CFL showed no statistically significant differences among them.
  
  
  CONCLUSIONS
  It can be concluded that both the low-level infrared laser and photoabsorbing cream with fluoride were effective in inhibiting the development of caries in enamel around orthodontic brackets, even in situations of high cariogenic challenge.
authors.affiliation: 1 School of Dentistry, Cruzeiro do Sul University (UNICSUL) , São Paulo-SP, Brazil .
authors.forename: Ângela Sueli Soares Braga
authors.initials: ÂS
authors.lastname: Lacerda
authors.forename: Fernando Seishim
authors.initials: FS
authors.lastname: Hanashiro
authors.forename: Giselle Rodrigues
authors.initials: GR
authors.lastname: de Sant'Anna
authors.forename: Washington
authors.initials: W
authors.lastname: Steagall Júnior
authors.forename: Patrícia Silva
authors.initials: PS
authors.lastname: Barbosa
authors.forename: Wanessa Christine
authors.initials: WC
authors.lastname: de Souza-Zaroni
mesh_terms: D000818:Animals; D002417:Cattle; D003743:Dental Enamel / Q000528:radiation effects; D005460:Fluorides, Topical / Q000494:pharmacology*; D066298:In Vitro Techniques; D054023:Lasers, Semiconductor; D016910:Orthodontic Brackets / Q000009:adverse effects*; D013499:Surface Properties; D017001:Tooth Demineralization / Q000517:prevention & control*
chemical_list: D005460:Fluorides, Topical