title: Acquired acid resistance of human enamel treated with laser (Er:YAG laser and Co2 laser) and acidulated phosphate fluoride treatment: An in vitro atomic emission spectrometry analysis.
abstract: BACKGROUND
  Dental caries is essentially a process of diffusion and dissolution. If the aspect of dissolution can be curtailed some degree of prevention can be achieved.
  
  
  OBJECTIVE
  The present study was carried out to evaluate and compare the effect of Er:YAG laser and Co2 laser irradiation combined with acidulated phosphate fluoride treatment on in vitro acid resistance of human enamel.
  
  
  METHODS
  An in vitro study was carried out on 30 human premolars to evaluate the enamel's acid resistance using an atomic emission spectrometry analysis.
  
  
  METHODS
  A total of 60 enamel specimens were prepared from 30 human premolars and were randomly assigned to 6 groups: (1) Untreated (control); (2) 1.23% acidulated phosphate fluoride (APF) gel application alone for 4 min; (3) Er:YAG laser treatment alone; (4) Co2 laser treatment alone; (5) Er:YAG laser + APF gel application; (6) Co2 laser + APF gel application. The specimens were then individually immersed in 5 ml of acetate buffer solution (0.1 mol/L, pH 4.5) and incubated at 37°C for 24 h, and the acid resistance was evaluated by determining the calcium ion concentration using the atomic emission spectrometry.
  
  
  METHODS
  An ANOVA model was constructed (P value of 0.05), followed by Tukey's test for multiple pair wise comparisons of mean values.
  
  
  RESULTS
  Significant differences were found between the control group and the test groups (P < 0.001).
  
  
  CONCLUSIONS
  Combining acidulated phosphate fluoride with either Er:YAG or Co2 laser had a synergistic effect in decreasing the enamel demineralization more than either fluoride treatment or laser treatment alone.
authors.affiliation: Department of Paedodontics, Mar Baselious Dental College, Kothamangalam, Ernakulam, Kerala, India.
authors.forename: Anju
authors.initials: A
authors.lastname: Mathew
authors.forename: N Venugopal
authors.initials: NV
authors.lastname: Reddy
authors.forename: D K
authors.initials: DK
authors.lastname: Sugumaran
authors.forename: Joby
authors.initials: J
authors.lastname: Peter
authors.forename: M
authors.initials: M
authors.lastname: Shameer
authors.forename: Liju Marcely
authors.initials: LM
authors.lastname: Dauravu
keywords: Acidulated phosphate fluoride; Co2 laser; Er:YAG laser; acid resistance