Sana M. Mansour, Essam E. Al-wakeel And Neven S. Aref,

ABSTRACT


Purpose: This Study Investigated The Effect Of Microwave Post-polymerization Treatment Of Bulk- Fill Resin Composite Used As Indirect Restoration Regarding; Degree Of Conversion, Surface Micohardness, Compressive Strength And Fracture Toughness.

Materials and Methods: Two Nanohybrid Resin Composites Were Used In The Study; One Is Incrementally-placed And The Other Is Bulk-fill. For Each Test, Ten Specimens Of Each Resin Composite Type Were Prepared According To Manufacturer�s Instructions (group I And II) And Divided Into Two Equal Subgroups; One (Ia And IIa) As A Control And The Other Subgroup (Ib And IIb) Exposed To A Microwave Post-polymerization Treatment At 550 W For 4 Min. The Degree Of Conversion, Compressive Strength, Surface Micohardness And Fracture Toughness Of The Different Groups Were Calculated. Student�s T-test Was Used To Analyze And Compare The Collected Data (p < 0.05).

Results: Bulk-fill Resin Composite Exhibited A Significant Increase In The Compressive Strength, And Fracture Toughness Mean Values Than Those Of The Incrementally-placed One. For Both Incrementally-placed And Bulk-fill Resin Composites, Significant Differences Between The Degree Of Conversion, Compressive Strength, Surface Micohardness And Fracture Toughness Means Of The Microwave-treated Group And Those Of The Control Group Were Detected.

Conclusions: Microwave Post-polymerization Treatment Is A Valuable Technique For Enhancing The Degree Of Conversion, Compressive Strength, Microhardness And Fracture Toughness Of Nanohybrid Resin Composites, Either Bulk-fill Or Incrementally-placed One When Used As Indirect Restoration. Bulk-fill Resin Composite Is A Material Of Choice For Indirect Restorations (inlays And Onlays).