STATEMENT OF PROBLEM: Assessing the quantity and distribution of residual coronal dentin is important in deciding the restorability of endodontically treated @entity4500 . PURPOSE: The purpose of this in  vitro study was to investigate the relationship between the cross-sectional area and location of remaining coronal tooth structure and the @entity174 resistance of restored @entity4500 after endodontic treatment. MATERIAL AND METHODS: Fifty-five extracted maxillary premolars received endodontic treatment and crown preparations. The @entity4500 were assigned to 11 groups of 5 @entity4500 according to the number and the location of missing axial walls. Impressions of the prepared @entity4500 were made to  fabricate dies. Each die was sectioned 1 mm above the finish line, and the dentin surface area  was measured. All @entity4500 were restored with composite resin cores and cast metal crowns. The specimens were thermocycled between 5  C and 55  C for 500 cycles before loading until failure with a universal testing machine. The results were analyzed with 1-way ANOVA and post hoc comparisons. RESULTS: Specimens with all axial walls intact around the access cavity had the highest mean @entity174 strength (1380.5   393.9 N). Groups with the palatal and 1 or 2 proximal walls missing showed the lowest mean failure loads (398.4 N   149.5 N and 344.7 N   91.2 N). The correlation between the surface area and the @entity174 resistance was 0.72 CONCLUSIONS: For restored endodontically treated maxillary premolars, a positive linear relationship was found between the remaining coronal dentin surface area and @entity174 strength. Residual dentin location influences @entity174 resistance.

Effect of remaining tooth structure on the XXXX resistance of endodontically-treated maxillary premolars: An in  vitro study.

@entity4500 :: ('MESH:D014071', 'Disease') :: ['teeth'] @entity174 :: ('MESH:D050723', 'Disease') :: ['fracture']
@entity174 :: (MESH:D050723,Disease) :: ['fracture']
