Comparison of fracture resistance of endodontically treated maxillary first premolar with mesio-occlusal-distal access restored with composite resin, fiber post, and prefabricated metal posts restored with/without full-coverage metal crowns

BACKGROUND: A myriad of materials and procedures have been recommended for restoring the root-filled teeth with significant loss of tooth structure and the most common method being the use of “posts.” MATERIAL AND METHODS: A mesio-occluso-distal preparation was done on eighty intact maxillary first premolars, followed by access preparation and cleaning and shaping with rotary files. All samples were obturated and divided into four groups (n = 20). In Group 1, 3-mm gutta-percha was removed and restored using composite resin; Group 2 – Group 1 + crowns; Group 3 – prefabricated fiber post + crowns; and Group 4 – prefabricated metal post + crowns. All the groups were subdivided into eight groups (n = 10), fractured with 90° vertical and 45° oblique loading by a universal testing machine. STATISTICAL ANALYSIS: Fracture resistance was analyzed and compared by means of two-factorial two-way analysis of variance and Scheffe's post hoc test. RESULTS: Under 90° loading, the fracture load of teeth restored with the Nayyar's composite resin core and crown was greatest. Under 45° loading, the fracture load of teeth restored with prefabricated metallic posts was significantly (P < 0.05) less than that in other groups. Under 45° load, group with fiber post exhibited significantly (P < 0.05) more number of favorable fractures than other groups. CONCLUSION: Under the conditions of vertical and oblique loadings, fiber post and composite resin core with a full-coverage crown is the most effective restorative modality for protecting the remaining tooth structure in pulpless teeth.