This study is conducted to compare the efficacy of surface pretreatment using air abrasion sandblasting aluminum oxide particles (Al2O3) versus not pretreatment in the repair capacity of defective composite restoration indicated for repair.

First the rationale for the repair, rather than the replacement of defective direct composite restorations proved a less invasive procedure with decreased tooth loss avoiding weakening and overtreatment of tooth. Less traumatic or stressful than replacement for patients with good acceptance; Increased longevity of the restoration; Reduction of potentially harmful effects on the dental pulp and Less risk of iatrogenic damage to adjacent teeth.

Secondary using surface treatment strategies aim to prepare a clean surface with high surface energy to provide better wettability with adequate surface roughness and surface area by removing the superficial layer of the aged composite which lead to increase integrity between old and new resin restoration.

Inclusion Criteria:

• Co-operative patients approving to participate in the trial.
• patient with occlusal defects class I or class II composite resin restorations indicated for repair.

Exclusion Criteria:

• Allergic history concerning methacrylate.

• Rampant caries.

  • Disabilities patient
  • Pregnancy
  • Heavy smoking.
  • Xerostomia.
  • Lack of compliance.
  • Evidence of parafunctional habits.
  • Temporomandibular joint disorders.

Double (Participant, Outcomes Assessor)