Radwa Mohamed Nagieb, Mona Riad And Mohamed Mostafa,

ABSTRACT


Aim: The Aim Of This Study Was To Evaluate The Effect Load Cycling On Fracture Resistance Of A New Bioactive Restorative Material (ACTIVA) And Compared With Nano Resin Composite Materials.

Materials & Methods: A Total Of 60 Upper Premolars Were Used In The Study. They Were Divided Into Two Groups Of 30 Specimens Each According To Type Of Restorative Materials. (Group A1) Was Restored By Bioactive Restorative Material (ACTIVA), And (group A2) Was Restored By Nano Hybrid Composite Restorative Material (Filtek Z250 XT). Each Group Was Divided Into 2 Subgroups Of 15specimens According To The Number Of Received Load Cycles That Represent 24 Hours (T1) And 3 Months (T2). Mesio-Occluso-Distal (MOD) Cavities Were Prepared In All The Specimens With A 2?0.2 Mm Pulpal Depth, 1.5?0.2 Mm Gingival Width, 2?0.2 Mm Axial Height. Adhesive System As Well As Composite Resin Application Was Done According To Manufacturer?s Instructions. After Cavity Preparation And Restoration Fracture Resistance Test Were Done Using The Universal Testing Machine (Instron Model 3345 Ingland). Samples Were Secured To The Lower Fixed Compartment Of Testing Machine By Tightening Screws. Fracture Test Was Done By Compressive Mode Of Load Applied Occlusally Using A Metallic Rod With Round Tip (3.6 Mm Diameter) Attached To The Upper Movable Compartment Of Testing Machine Traveling At Cross-head Speed Of 0.5mm/min. The Load Required To Fracture Was Recorded In Newton.

Results: There Was No Statistical Significant Difference Between Both Tested Materials. The Fracture Resistance Means Values Significantly Influenced By The Number Of Cycles Applied (P < 0.05).

Conclusions: Cyclic Loading Affects The Fracture Resistance Of Tested Materials And Both Materials Can Be Successfully Used To Restore Class II Carious Lesions.