Effect of cyclic loading on marginal adaptation and bond strength in direct vs. indirect class II MO composite restorations.
This study evaluated the effect of cyclic loading on the marginal adaptation and microtensile bond strength of direct vs indirect Class II composite restorations in an in-vitro model. Forty Class II cavities were prepared on the mesial surface of extracted human maxillary first premolars and divided into two groups: Group I--direct composite restorations and Group II--indirect composite restorations. Groups I and II were further divided into subgroups: A (without cyclic loading) and B (with cyclic loading of 150,000 cycles at 60N). The gingival margin of the proximal box was evaluated at 200x magnification for marginal adaptation in a low vacuum scanning electron microscope. The restorations were sectioned perpendicular to the bonded surface into 1 mm thickslabs. The slabswere further trimmed at the interface to produce a cross-sectional surface area of approximately 1 mm2. All specimens were subjected to microtensile bond strength testing. The marginal adaptation was analyzed using descriptive studies and bond strength data were analyzed by one-way ANOVA test. The indirect composite restorations performed better under cyclic loading.
Aggarwal
Vivek
V
Department of Conservative Dentistry and Endodontics, Centre for Dental Education and Research, All India Institute of Medical Sciences, New Delhi, India.
Logani
Ajay
A
Jain
Veena
V
Shah
Naseem
N
D000134:Acid Etching, Dental; D020906:Air Abrasion, Dental; D001641:Bicuspid; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003736:Dental Cavity Lining; D003737:Dental Cavity Preparation / Q000145:classification; D003743:Dental Enamel / Q000648:ultrastructure; D018772:Dental Marginal Adaptation; D003764:Dental Materials / Q000737:chemistry*; D003775:Dental Polishing; D003793:Dental Restoration, Permanent / Q000145:classification*; D003799:Dental Stress Analysis / Q000295:instrumentation; D017220:Dentin-Bonding Agents / Q000737:chemistry; D006801:Humans; D007284:Inlays / Q000145:classification; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength
D003188:Composite Resins; D003764:Dental Materials; D017220:Dentin-Bonding Agents; D011109:Polymethacrylic Acids; C462240:RelyX ARC; D019279:Resin Cements; C115612:single bond; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate