INFLUENCE OF INNER CORONAL DENTIN ON THE FRACTURE STRENGTH OF POST-ENDODONTIC RESTORED UPPER LATERAL INCISORS
INFLUENCE OF INNER CORONAL DENTIN ON THE FRACTURE STRENGTH OF POST-ENDODONTIC RESTORED UPPER LATERAL INCISORS

Summary/Abstract: Purpose. This in vitro research studied the influence of the amount of inner ferrule (IF) on fracture strength of restored endodontically treated teeth (ETT). Material and methods. 72 upper lateral incisors (ULI) were extracted, treated endodontically, and divided into the following groups: A 1/2, without IF (0mm); B 1/2, 1mm of IF, and C 1/2, 2mm of IF, respectively. For our experiments Y-TZP VALL-POST (WALL-CER, Slovenia) with 3 retentive rings, coronally upgraded with direct composite MultiCore (Ivoclar) were used. The experimental posts were cemented with composite cement Multi-link (Ivoclar), embedded in blocks (Pro-Base acrylic resin), and loaded (45 degrees) on Testing Machine (Instron 4301 USA) until fracture (1mm/min crosshead speed). Fracture loads and modes were analyzed. Two-way of variance analysis was used (significance p<0.05). Results. For fracture loads, mean values (±SD) were measured in Newton’s (N). For groups A1 / B1 / C1 (Ø = 1.4mm) and A2 / B2 / C2 (Ø = 1.6mm), we obtained the following results: A1 = 305.04N (±74.04); B1 = 351.07N (±77.17); C1 = 579.11N (±112.21) and groups A2 = 373,17N (±49.04); B2 = 393.03N (±73.11); C2 = 618.79N (±130.02). There occurred reparable failure patterns in different percentages concerning the IF: A1 = 100% / A2 = 91.5% (0mm IF); groups B1 = 84.3% / B2 = 66.6% (1mm IF), and groups C1 = 75.0% / C2 = 57.4% (2mm IF). Conclusion. Within the confines of this research the ETT with 1mm IF and without IF demonstrated considerably lower failure loads than those with 2mm IF, with reparable failure patterns in all groups ULI.

• Details
• Contents