Stress generation in mandibular anterior teeth restored with different types of post-and-core at various levels of ferrule

Effect of Ferrule Location with Varying Heights on Fracture Resistance and Failure Mode of Restored Endodontically Treated Maxillary Incisors

“…The specimens in CF2 with 360° parallel walls of 2 mm height were more resistant to fracture than specimens of NF (no ferrule), and specimens of IF1 through IF4 that had 2 remaining walls with varying heights. These data confirmed other studies that indicated that the quantity and quality of the remaining coronal structure is a determining factor for the mechanical strength and prognosis of a tooth …”

“…This is because the tooth is subjected to the incisal load as the compressive force in the buccal and high tension stress occurs on the surface of the tooth prepared on the lingual side, causing fracture. The reduced number of root fractures could be due to the dentin‐like elastic modulus of the fiber post that allows it to better absorb the concentrated forces along the root . The subosseous propagation of cracks (below mimicked bone support) was characterized by a reduced number on the surface of the dentin.…”

“…These data confirmed other studies that indicated that the quantity and quality of the remaining coronal structure is a determining factor for the mechanical strength and prognosis of a tooth. [27][28][29] The first null hypothesis that the fracture resistance and the failure mode would not be affected when a ferrule formed by 2 remaining walls of 2 mm height, absence of lingual wall and 1 proximal wall, was rejected. Fracture resistance of IF2 (494 ± 137 N) was significantly lower compared to a complete ferrule CF2 (707 ± 162 N), p = 0.001.…”

“…The reduced number of root fractures could be due to the dentin-like elastic modulus of the fiber post that allows it to better absorb the concentrated forces along the root. 9,29,32,34 The subosseous propagation of cracks (below mimicked bone support) was characterized by a reduced number on the surface of the dentin. This can also be attributed to the modulus of elasticity of the fiber post.…”

Gingival tissue reaction to direct adhesive restoration: A preliminary study

“…The biologic width (Gargiulo, Wentz, & Orban, 1961;Hamasni & El Hajj, 2017) of the chosen teeth was respected, also considering the subgingival part of the defect that corresponded to apical margin of the pre-endodontic conservative treatment. However, to complete the selected teeth rehabilitation, it was necessary to prepare a dental crown and to obtain a correct effect of ferrule configuration using of a 1.5-to 2-mm-high ferrule (Cakan, Yuzugullu, & Canay, 2008;Eismann & Radke, 1987;Juloski, Köken, & Ferrari, 2017;Politano, Fabianelli, Papacchini, & Cerutti, 2016;Savychuk, Manda, Galanis, Provatidis, & Koidis, 2017;Zhang et al, 2015). Anyway, on the teeth considered, an intervention for crown lengthening had been necessary to guarantee the correct morphology of the tissues in relation to the planned dental rehabilitation and/or with respect to of the biologic width considering an effective "ferrule effect.…”