title: Comparative evaluation of the effect of Er:YAG laser and low level laser irradiation combined with CPP-ACPF cream on treatment of enamel caries.
abstract: OBJECTIVE
  This study investigated the effectiveness of low power red and infrared lasers and that of Er:YAG laser, in association with CPP-ACPF cream, on remineralization of white spot lesions.
  
  
  METHODS
  Fifty intact premolars were immersed in a demineralization solution for 10 weeks to induce caries like lesions and then were divided into five groups. In group 1, the teeth were covered with a CPP-ACPF cream for 3 minutes and then irradiated with a low power red laser (660 nm, 200 mW) for 1 minute through the cream. In group 2, the treatment was the same as that in group 1, but an infrared laser (810 nm, 200 mW) was employed. The specimens in group 3 were irradiated with an Er:YAG laser (100 mJ, 10 Hz) combined with CPP-ACPF. In group 4, the CPP-ACPF cream was applied for 4 minutes and group 5 was submitted to neither laser nor CPP-ACPF. The micro Vickers hardness was compared at 20, 60 and 100 µ from the enamel surface among the groups.
  
  
  RESULTS
  The highest microhardness was observed in the low power red and Er:YAG laser groups and the lowest one belonged to the CPP-ACPF alone and control groups. However, no significant difference was found in microhardness of the experimental groups at any of the evaluation depths (p>0.05).
  
  
  CONCLUSIONS
  With the laser parameters used in this study, neither the combined application of Er:YAG laser with CPP-ACPF nor the combination of low power lasers with CPP-ACPF provided a significant increase in remineralization of enamel caries. Key words:Low level laser, Er:YAG, laser, enamel caries, CPP-ACP, microhardness, white spot lesion.
authors.affiliation: DDS MS, Associate Professor of Orthodontics. Dental Research Center, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Farzin
authors.initials: F
authors.lastname: Heravi
authors.affiliation: DDS MS, Assistant Professor of Orthodontics. Dental Research Center, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran.
authors.forename: Farzaneh
authors.initials: F
authors.lastname: Ahrari
authors.affiliation: DDS, Private practice. Mashhad, Iran.
authors.forename: Mahdieh
authors.initials: M
authors.lastname: Mahdavi
authors.affiliation: DDS, Private practice. Mashhad, Iran.
authors.forename: Soroush
authors.initials: S
authors.lastname: Basafa