title: Effect of ascorbic acid, ethanol and acetone on adhesion between the treated fiber posts and composite resin cores.
abstract: OBJECTIVE
  The aim of the present study was to assess the effect of ascorbic acid, ethanol and acetone on microtensile bond strength between fiber posts pre-treated with hydrogen peroxide and composite resin cores.
  
  
  METHODS
  Twenty four fiber posts were pre-treated with 24% hydrogen peroxide and divided into 4 groups as follows: G1: no treatment, as control group; G2: treatment with 10% ascorbic acid solution for 5 minutes; G3: treatment with 70% ethanol solution for 5 minutes; and G4: treatment with 70% acetone solution for 5 minutes. Each fiber post was surrounded by a cylinder-shaped polyglass matrix which was subsequently filled with composite resin. Two sections from each sample were selected for microtensile test at a crosshead with speed of 0.5 mm/min. Statistical analyses were performed using one-way ANOVA and a post hoc Tukey HSD test. Fractured surfaces were observed under a stereomicroscope at ×20 magnification. The fractured surfaces of the specimens were observed and evaluated under a SEM.
  
  
  RESULTS
  MEANS OF MICROTENSILE BOND STRENGTH VALUES (MPA) AND STANDARD DEVIATIONS IN THE GROUPS WERE AS FOLLOWS: G1: 9.70±0.81; G2: 12.62±1.80; G3: 16.60±1.93; and G4: 21.24±1.95. G4 and G1 had the highest and the lowest bond strength values, respectively. A greater bond strength value was seen in G3 compared to G2. There were significant differences between all the groups (P<.001). All the failures were of the adhesive mode.
  
  
  CONCLUSIONS
  Application of antioxidant agents may increase microtensile bond strength between fiber posts treated with hydrogen peroxide and composite cores. Acetone increased bond strength more than ascorbic acid and ethanol.
authors.affiliation: Member of Dental Research Center, Department of Operative Dentistry, Dental School, Hamadan University of Medical Sciences, Hamadan, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Khamverdi
authors.forename: Khamverdi
authors.initials: K
authors.lastname: Zahra
authors.forename: Reza
authors.initials: R
authors.lastname: Talebian
authors.forename: Talebian
authors.initials: T
authors.lastname: Reza