title: In situ investigation of the effect of TiF4 and CO2 laser irradiation on the permeability of eroded enamel.
abstract: OBJECTIVE
  Interest in erosion and its role in tooth wear has increased considerably. Due to the limited contribution of patients in modifying their dietary habits, therapeutic resources aiming to reduce the progression of erosion-like lesions have been discussed. This study sought to evaluate the effect of TiF4 and CO2 laser in controlling the permeability of in situ eroded enamel.
  
  
  METHODS
  Ten volunteers wore an intraoral palatal device containing two enamel slabs, treated with TiF4 gel and TiF4 gel + CO2 or placebo gel and placebo gel + CO2. After the washout period, volunteers were crossed over to the other treatment. During both phases, specimens were submitted to erosive challenges and then evaluated for permeability measured as the percentage of copper ion penetration over the total enamel thickness.
  
  
  RESULTS
  Two-way analysis of variance (ANOVA) revealed that there was a significant interaction between the factors under study (p = 0.0002). Tukey's test showed that TiF4 significantly reduced the enamel permeability of eroded enamel specimens, regardless of whether CO2 laser irradiation was performed.
  
  
  CONCLUSIONS
  It may be concluded that when the placebo gel was applied, CO2 laser was able to reduce enamel permeability; however, when TiF4 was applied, laser irradiation did not imply a reduction in permeability. TiF4 provided a lower permeability of eroded enamel, regardless of whether the CO2 laser was used.
authors.affiliation: Ribeirão Preto School of Dentistry - USP, Department of Restorative Dentistry, Av. do Café, S/N Monte Alegre, CEP 14040-904, Ribeirão Preto, São Paulo, Brazil. Electronic address: taisalepri@yahoo.com.br.
authors.forename: Taísa Penazzo
authors.initials: TP
authors.lastname: Lepri
authors.affiliation: Dental School, University of Ribeirão Preto, Avenida Costábile Romano, 2201, Ribeirânia, CEP 14096-900, Ribeirão Preto, São Paulo, Brazil. Electronic address: vi.colucci@gmail.com.
authors.forename: Vivian
authors.initials: V
authors.lastname: Colucci
authors.affiliation: São Leopoldo Mandic Institute and Dental Research Center, Department of Restorative Dentistry, Av. José Rocha Junqueira, 13, CEP 13045-755, Campinas, São Paulo, Brazil. Electronic address: cturssi@yahoo.com.
authors.forename: Cecília Pedroso
authors.initials: CP
authors.lastname: Turssi
authors.affiliation: Ribeirão Preto School of Dentistry - USP, Department of Restorative Dentistry, Av. do Café, S/N Monte Alegre, CEP 14040-904, Ribeirão Preto, São Paulo, Brazil. Electronic address: silmaracorona@forp.usp.
authors.forename: Silmara Aparecida Milori
authors.initials: SA
authors.lastname: Corona
mesh_terms: D000328:Adult; D000818:Animals; D018441:Biofilms; D002327:Cariostatic Agents / Q000494:pharmacology*; D002417:Cattle; D018592:Cross-Over Studies; D003743:Dental Enamel / Q000187:drug effects* / Q000528:radiation effects*; D005459:Fluorides / Q000494:pharmacology*; D005460:Fluorides, Topical / Q000494:pharmacology*; D005782:Gels; D006801:Humans; D054020:Lasers, Gas / Q000627:therapeutic use*; D010539:Permeability; D013499:Surface Properties; D014025:Titanium / Q000494:pharmacology*; D014077:Tooth Erosion / Q000188:drug therapy* / Q000532:radiotherapy*
chemical_list: D002327:Cariostatic Agents; D005460:Fluorides, Topical; D005782:Gels; D014025:Titanium; D005459:Fluorides; C032240:titanium tetrafluoride
keywords: CO(2) laser; Enamel; Erosion; Permeability; TiF(4)