title: Four-year randomized clinical trial of oxalic acid pretreatment in restorations of non-carious cervical lesions.
abstract: OBJECTIVE
  The aim of this study was to evaluate the efficiency of oxalic acid (BisBlock) on restorations of non-carious cervical lesions.
  
  
  METHODS
  One operator placed 90 restorations randomly divided into two groups in 20 patients under cotton rolls isolation: Control Group-two-step etch-and-rinse adhesive technique; and Experimental Group-two-step etch-and-rinse adhesive technique with oxalic acid pretreatment after acid-etched dentin. The restorative adhesive system used was XP Bond/Durafill. The restorations were directly assessed by two independent examiners, using the modified United States Public Health Service (USPHS) criteria at the baseline and 4 years. Data were statistically analyzed using the Fisher and McNemar tests (p < 0.05).
  
  
  RESULTS
  Fifteen patients (75%) were available for recall after 4 years. The McNemar test detected significant differences within the Experimental Group between the baseline and 4-year evaluations for retention (p < 0.05). For the Control Group, there was no significant difference (p > 0.05) between the periods. The Fisher test showed no statistically significant difference between the groups for all other criteria (p > 0.05).
  
  
  CONCLUSIONS
  After 4 years of service, the use of oxalic acid did not influence the clinical performance of restorations when it was used under composite resin restorations.
authors.affiliation: Department of Operative Dentistry, Faculty of Pharmacy, Dentistry and Nursing, Federal University of Ceará, Fortaleza, Ceará, Brazil.
authors.forename: Nadine Luísa Guimarães
authors.initials: NL
authors.lastname: Albuquerque
authors.affiliation: Department of Operative Dentistry, Faculty of Pharmacy, Dentistry and Nursing, Federal University of Ceará, Fortaleza, Ceará, Brazil.|School of Dentistry, University of Fortaleza, Fortaleza, Ceará, Brazil.
authors.forename: André Mattos Brito
authors.initials: AM
authors.lastname: de Souza
authors.affiliation: Department of Operative Dentistry, Faculty of Pharmacy, Dentistry and Nursing, Federal University of Ceará, Fortaleza, Ceará, Brazil.|School of Dentistry, University of Fortaleza, Fortaleza, Ceará, Brazil.
authors.forename: Maria Denise Rodrigues
authors.initials: MD
authors.lastname: de Moraes
authors.affiliation: Department of Operative Dentistry, Faculty of Pharmacy, Dentistry and Nursing, Federal University of Ceará, Fortaleza, Ceará, Brazil.
authors.forename: Juliano Sartori
authors.initials: JS
authors.lastname: Mendonça
authors.affiliation: Department of Operative Dentistry, Faculty of Pharmacy, Dentistry and Nursing, Federal University of Ceará, Fortaleza, Ceará, Brazil.
authors.forename: Lidiany Karla Azevedo
authors.initials: LK
authors.lastname: Rodrigues
authors.affiliation: Department of Operative Dentistry, Faculty of Pharmacy, Dentistry and Nursing, Federal University of Ceará, Fortaleza, Ceará, Brazil. sergiosantiago@ufc.br.
authors.forename: Sérgio Lima
authors.initials: SL
authors.lastname: Santiago
mesh_terms: D000134:Acid Etching, Dental; D000328:Adult; D003188:Composite Resins; D003793:Dental Restoration, Permanent / Q000379:methods*; D017220:Dentin-Bonding Agents; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019815:Oxalic Acid / Q000627:therapeutic use*; D019237:Tooth Cervix / Q000473:pathology; D016896:Treatment Outcome
chemical_list: C514542:BisBlock; D003188:Composite Resins; D017220:Dentin-Bonding Agents; C532387:XP-Bond; C039734:Durafill; D019815:Oxalic Acid
keywords: Adhesive; Clinical trial; Dentin hypersensitivity; Oxalates