Fracture Resistance of Endodontically Treated Premolars Restored with Ormocer and Packable Composite

Abstract

In this study, mesiodistocclusal (MOD) cavity preparations of endodontically treated maxillary premolars that were enlarged to size #50 were restored using three restorative materials (one ormocer, one packable composite, and one high-copper amalgam) and two application techniques (with or without coronal radicular technique). Copper rings were filled with self-curing polymethylmethacrylate resin and the teeth were placed into resin up to the level of the CEJ. The teeth were grouped according to the restorative material and technique, mounted in a Universal Testing Machine, and the buccal walls subjected to a slowly increasing compressive force until fracture occurred. The force of fracture of the walls of each tooth was recorded and the results in the various groups compared. The group restored with packable composite without radicular extension showed the highest resistance to fracture (p < 0.05). Both groups restored with amalgam were significantly weaker than all the other groups (p < 0.05).

Effects of fiber-glass-reinforced composite restorations on fracture resistance and failure mode of endodontically treated molars

“…The clinical outcomes of direct resin composite restorations, which represent a less invasive approach to restoring endodontic posterior teeth, are variable in the literature, ranging from catastrophic to acceptable [4][5][6]. More recently, the insertion of fiber posts within direct composite restorations has been tested with the intention of providing increased fracture resistance [7][8][9]. Indeed, within the radicular dentin, the fiber post serves as a distributor of stresses and loads applied to the composite restoration [10], providing reinforcement even in the presence of sufficient residual coronal dentin [11,12].…”

Effect of restorative techniques on fracture resistance of endodontically treated premolars

“…The primary cause for this difference is the small sample size, whereby only 10 samples were used in each group. However, other studies have used the same sample size of 10 in each group [36,37].…”

“…It has been shown that amalgam-restored teeth were less resistant to fracture compared to packable composite and ormocer-restored teeth [36]. Amalgam restoration actually does not strengthen the teeth and behaves as a bulk replacement of lost tooth structure.…”

Rethinking ferrule – a new approach to an old dilemma

“…Composite resin with a dentine bonding agent has frequently been implicated as a material that can strengthen the tooth and reinforce cusps compared to amalgam. [65][66][67][68] Teeth with wide MOD cavities restored with amalgam have repeatedly shown cusp failure due to the inability of this material to strengthen weakened cusps. 69 This is true both because amalgam does not bond to tooth structure and it requires undercuts for retention, which weakens the remaining walls.…”

“…These include using complex amalgam restorations, 91,92 overlays 65 or composite restorations. 67,93 More recently partial restorations like indirect onlays have been suggested as a restoration that preserves more sound tooth structure than does a full coverage crown while at the same time provides cuspal coverage to protect weakened cusps. 7 By implementing the proposed risk assessment classification of the remaining dentine in severely broken down teeth, practitioners will consider alternative methods of restoring these teeth.…”