Comparative evaluation of fracture resistance of root canal-treated premolars with MOD cavities restored using different techniques: An in vitro study.

Objective: This study was designed to assess the effect of multiple coronal postendodontic restoration techniques on the ability to resist fracture and failure pattern of endodontically treated maxillary premolars having mesioocclusodistal (MOD) cavities. Materials and Methods: A total of 65 two-rooted maxillary premolars were taken and randomly divided into five groups (n = 13). In all teeth except the control group, MOD cavities were prepared, and endodontic treatment was carried out. Each tooth was embedded in a cold cure acrylic resin cylinder 2.0 mm below the cementoenamel junction. Groups were classified as follows; Group 1: Intact teeth (control), Group 2: Resin-restored group (CR), Group 3: Post and resin group (HFP + CR), Group 4: Resin and post group (CR + HFP), and Group 5: Polyethylene fiber (Ribbond) and post group (PEF + HFP + CR). Tooth samples with resin were loaded in a universal testing machine until fracture occurred. Loads at which fracture occurred were recorded, fracture patterns were analyzed, and statistical analysis was done (α = 0.05). Results: In Groups 1 and 5, maximum fracture resistance was observed, without any significant difference between these two groups (P > 0.05). No statistically noteworthy difference was detected between Groups 2 and 4 ( P > 0.05). The fracture resistance of Groups 1 and 5 was significantly greater than Groups 2, 3, and 4 ( P < 0.05). Group 3 had the least fracture resistance ( P < 0.05). In all the groups except Group 3, a maximum number of fractures were favorable. Conclusion: Utilization of horizontal fiber post along with polyethylene fibers significantly increases the fracture resistance of endodontically treated premolars with MOD cavities. Placement of horizontal fiber post before restoration of tooth leads to a greater number of unfavorable fractures. [ABSTRACT FROM AUTHOR]