COMPARISON OF FRACTURE RESISTANCE OF POSTERIOR TEETH RESTORED WITH DUAL CURE FLOWABLE COMPOSITE RESIN, ZIRCONOMER AND UNIVERSAL COMPOSITE RESTORATIVE MATERIAL: AN IN-VITRO STUDY

Dental caries remains one of the most prevalent oral diseases worldwide and frequently 
results in extensive loss of tooth structure requiring restorative treatment.¹ Restoration of 
posterior teeth with extensive mesio-occluso-distal (MOD) cavity preparations presents a 
significant challenge in restorative dentistry because such preparations considerably weaken 
the remaining tooth structure.²˒³ 
The fracture resistance of a tooth is greatly influenced by the amount of remaining sound 
tooth structure. Loss of marginal ridges and supporting dentin during cavity preparation 
results in increased cuspal deflection, reduced stiffness, and greater susceptibility to fracture 
under occlusal loading.³˒⁴ Previous studies have shown that MOD cavity preparations 
significantly reduce the fracture strength and rigidity of posterior teeth.³˒⁴ 
Posterior teeth are continuously subjected to compressive, tensile, shear, and torsional forces 
during mastication. Therefore, restorative materials used in stress-bearing posterior regions 
should possess adequate mechanical properties, fracture toughness, and resistance to 
functional loading.²˒⁵ 
Premolars are considered more susceptible to fracture because of their anatomical 
morphology and steep cuspal inclinations. Their position in the dental arch subjects them to 
considerable occlusal stresses during mastication, making them suitable for in vitro fracture 
resistance studies.⁵˒⁶