Bond strength of composite resin to bleached enamel
Yomna Yasin Jad, B Mostafa M. Ahmed Hassan, Mirvat M. Salama, Eman Abd-ELGhany SheblPurpose
The aim of the present study was to assess the effect of 2 weeks delay period on shear bond strength of composite to enamel using two different bleaching techniques (in-office and home bleaching).
Materials and methods
Thirty extracted premolars were selected for this study. The prepared specimens were randomly divided into three equal groups (10 specimens each) as follow; group I: unbleached enamel (control group), group II: bleached with Opalescence Boost 40%, and group III: bleached with Philips Zoom NiteWhite 22%. Buccal surfaces of all specimens were flattened using fine diamond bur. After etching and bonding procedures of enamel, composite resin (Filtek Z350 XT) was applied by the aid of a polyethylene mold (2 mm diameter and 2 mm height). The specimens were stored in artificial saliva for 2 weeks in an incubator. The shear bond strength was measured using a universal testing machine at across head speed of 0.5 mm/min then the fractured surfaces were examined under the stereomicroscope to determine the type of failure.
Results
One-way analysis of variance test showed a significant difference between groups I and II and also between groups I and III recording
Conclusion
Two weeks delay period prior to composite resin adhesiveness to bleached enamel was effective to recover the reduction of shear bond strength following either in-office or at-home bleaching techniques.