Objective: The aim of this study was to evaluate the efficiency of oxalic acid (BisBlock) on restorations of non-carious cervical lesions.
Materials and 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).
Conclusion: 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.
Keywords: Adhesive; Clinical trial; Dentin hypersensitivity; Oxalates.