title: Effect of various antioxidants on the shear bond strength of composite resin to bleached enamel: An in vitro study.
abstract: OBJECTIVE
  The aim of this in vitro study was to evaluate and compare the effect of 10% sodium ascorbate, 6.5% proanthocyanidin, and 5% lycopene on the bond strength of composite resin to bleached enamel.
  
  
  METHODS
  Labial enamel surfaces of 100 extracted human maxillary central incisors were used in this study. Twenty teeth served as group I (control) and received no bleaching treatment. The remaining 80 teeth were randomly divided into four groups of 20 teeth each, based on the antioxidant used as follows: group II- bleaching with 35% carbamide peroxide gel for 30 min without the use of an antioxidant, group III- bleaching followed by use of 10% sodium ascorbate solution, group IV- bleaching followed by use of 6.5% proanthocyanidin, and group V- bleaching followed by use of 5% lycopene. These groups were further subdivided into two subgroups of 10 teeth each, based on whether composite buildup was done immediately (subgroup A) or after a delay of 2 weeks (subgroup B) post bleaching. Shear bond strength of the specimens was tested under universal testing machine. The data were tabulated and statistically analyzed.
  
  
  RESULTS
  Significantly higher shear bond strength values were observed in teeth treated with control group prior to bonding, followed by sodium ascorbate group.
  
  
  CONCLUSIONS
  Within the limitations of this study, it can be concluded all the antioxidants used in this study increased the bond strength of bleached enamel. Among the antioxidant groups, sodium ascorbate showed significantly higher bond strength compared to proanthocyanidin and lycopene.
authors.affiliation: Department of Conservative Dentistry, SRM Dental College, Ramapuram, Chennai, India.
authors.forename: Mageshwaran Thandalam
authors.initials: MT
authors.lastname: Arumugam
authors.affiliation: Department of Conservative Dentistry, SRM Dental College, Ramapuram, Chennai, India.
authors.forename: Ravikumar
authors.initials: R
authors.lastname: Nesamani
authors.affiliation: Department of Conservative Dentistry, SRM Dental College, Ramapuram, Chennai, India.
authors.forename: Karthikeyan
authors.initials: K
authors.lastname: Kittappa
authors.affiliation: Department of Conservative Dentistry, SRM Dental College, Ramapuram, Chennai, India.
authors.forename: Kavitha
authors.initials: K
authors.lastname: Sanjeev
authors.affiliation: Department of Conservative Dentistry, SRM Dental College, Ramapuram, Chennai, India.
authors.forename: Mahalaxmi
authors.initials: M
authors.lastname: Sekar
keywords: Antioxidant; bleaching; lycopene; proanthocyanidin; shear bond strength; sodium ascorbate