title: Immediate and short-term effects of in-office desensitizing treatments for dentinal tubule occlusion.
abstract: OBJECTIVE
  The objective of this in vitro study was to evaluate the immediate and short-term effects of laser neodymium-doped yttrium aluminum garnet (Nd:YAG) irradiation and in-office desensitizing treatment on dentin tubule occlusion.
  
  
  BACKGROUND
  Literature shows a lack of long-lasting treatments for dentin hypersensitivity.
  
  
  METHODS
  Forty-eight dentin slabs (4×4×2 mm) were ground flat, polished, and treated with 27% ethylenediaminetetraacetic acid (EDTA) to open the dentinal tubules. Specimens were randomly divided into the following experimental groups (n=12): Group 1: Control (no treatment); Group 2: Nd:YAG laser irradiation (100 mJ, 85 J/cm(2) per pulse with a quartz fiber of 400 μm, in scanning movements); Group 3: In-office prophylaxis with pumice; Group 4: In-office Colgate Sensitive Pro-Relief™ Desensitizing Paste. Treatments were performed according to the manufacturer's instructions. After treatment, the specimens were submitted to a sequence of erosive and abrasive challenges, twice a day for 5 days. The specimens were qualitatively and quantitatively evaluated by scanning electron microscopy immediately after treatment and after 4 and 5 days. The response variable was the amount of occluded dentin tubules per area, determined by three different examiners with the use of visual criteria, with a standardized grade created in the PowerPoint program. Data were compared with ANOVA and Tukey's test, considering a 5% significance level.
  
  
  RESULTS
  Immediately after treatment, a reduction in the number of opened dentin tubules was observed for the laser group when compared with the control group (p<0.05). After the experimental procedures, there were no quantitative differences between the amount of opened dentin tubules for all groups; however, micrographs showed some qualitative tubule occlusion for the laser group after the erosive/abrasive challenge.
  
  
  CONCLUSIONS
  only laser irradiation was capable of immediately sealing the dentinal tubules; however, none of the treatments showed efficacy in maintaining tubule occlusion after the chemical and mechanical challenges.
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, University of São Paulo São Paulo, SP, Brazil.
authors.forename: Milena Traversa
authors.initials: MT
authors.lastname: Palazon
authors.forename: Tais
authors.initials: T
authors.lastname: Scaramucci
authors.forename: Ana Cecilia Correa
authors.initials: AC
authors.lastname: Aranha
authors.forename: Renato Araújo
authors.initials: RA
authors.lastname: Prates
authors.forename: Karina Monteleone
authors.initials: KM
authors.lastname: Lachowski
authors.forename: Fernando S
authors.initials: FS
authors.lastname: Hanashiro
authors.forename: Michel Nicolau
authors.initials: MN
authors.lastname: Youssef
mesh_terms: D002130:Calcium Phosphates / Q000494:pharmacology; D045424:Complex Mixtures; D003770:Dental Offices; D003802:Dentifrices; D057133:Dentin Desensitizing Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D003807:Dentin Sensitivity; D004492:Edetic Acid; D006801:Humans; D053844:Lasers, Solid-State; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D008964:Molar, Third; D010756:Phosphoric Acids / Q000494:pharmacology; D017680:Potassium Compounds; D013997:Time Factors
chemical_list: D002130:Calcium Phosphates; D045424:Complex Mixtures; D003802:Dentifrices; D057133:Dentin Desensitizing Agents; D010756:Phosphoric Acids; D017680:Potassium Compounds; C444700:colgate sensitive; D004492:Edetic Acid; C030242:phosphoric acid