title: Effect of 10% Sodium Ascorbate on Shear Bond Strength of Bleached Teeth - An in-vitro Study.
abstract: BACKGROUND
  Patient often requires some additional interventions such as replacement of old restorations, laminates and veneers after bleaching, for aesthetic purposes. The residual oxygen inhibits polymerization of resin based materials which results in reduced bond strength of the restorations. Some techniques are available to solve the clinical problems related to the post bleach compromised bond strength.
  
  
  OBJECTIVE
  The purpose of this study is to evaluate, the role of 10% sodium ascorbate on reversing the compromised bond strength and compare enamel shear bond strength of 5th and 6th generation dentine bonding agents on bleached and unbleached teeth.
  
  
  METHODS
  Eighty freshly extracted human anterior teeth were assigned in to Group A and Group B of 40 teeth each. Samples in both groups were subdivided in to 4 subgroups of 10 teeth each. In Group A composite resins was bonded using 5th generation dentine bonding agent (3M Single Bond) and Group B was bonded using 6th generation (3M ESPE Adper SE Plus). Subgroups were subjected to the procedure as, A1;B1 etching and bonding (control), A2; B2 bleaching, etching and immediate bonding, A3; B3 bleaching,10% ascorbic acid treatment for 10 minutes after that etching and bonding immediately, A4; B4 bleaching, storage in artificial saliva for 4 days and then etching and bonding. Pola office, in office bleach (SDI (082216) was used for bleaching. The specimens were subjected to shear load in a Universal testing machine to evaluate bond strength.
  
  
  RESULTS
  A decrease in bond strength was seen with 6th generation adhesive system compared to 5th generation bonding system, which is statistically significant, p<0.001.
  
  
  CONCLUSIONS
  Treating the bleached enamel surfaces when treated with 10% sodium ascorbate, which reverses the compromised bond strength and is a good alternative to delayed bonding.
authors.affiliation: Reader and P.G. Guide, Department of Conservative, Dentistry & Endodontics, Vasantdada Patil Dental College , Kavalapur, Sangli, Maharashtra, India .
authors.forename: Munavalli
authors.initials: M
authors.lastname: Anil
authors.affiliation: HOD and Professor, Department of Conservative Dentistry & Endodontics, Coorg Institute of Dental Sciences , Virajpet, Coorg, Karnataka, India .
authors.forename: K C
authors.initials: KC
authors.lastname: Ponnappa
authors.affiliation: Reader, Department of Conservative Dentistry & Endodontics, Jodhpur Dental College General Hospital , Jodhpur, Rajasthan, India .
authors.forename: Mirdha
authors.initials: M
authors.lastname: Nitin
authors.affiliation: Reader, Department of Prosthodontics, Vasantdada Patil Dental College , Kavalapur, Sangli, Maharashtra, India .
authors.forename: Sachhi
authors.initials: S
authors.lastname: Ramesh
authors.affiliation: Reader, Department of Conservative Dentistry & Endodontics, Vasantdada Patil Dental College , Kavalapur, Sangli, Maharashtra, India .
authors.forename: Kambale
authors.initials: K
authors.lastname: Sharanappa
authors.affiliation: Postgraduate Student, Department of Conservative Dentistry & Endodontics, Vasantdada Patil Dental College , Kavalapur, Sangli, Maharashtra, India .
authors.forename: Ajgaonkar
authors.initials: A
authors.lastname: Nishant
keywords: Dentin Conditioner; Dentin adhesive agents; Tooth Bleaching; Vitamin C