title: Effect of tapering internal coronal walls on fracture resistance of anterior teeth treated with cast post and core: In vitro study.
abstract: When fabricating indirect post and core, internal coronal walls are tapered to remove undercuts and allow a better adaptation. To evaluate the fracture strength of anterior tooth reconstructed with post and core and crowned, with two different taper of internal coronal walls, 6° and 30° to the long axis, two groups of 30 clear plastic analogues simulating endodontically treated maxillary central incisors were prepared. The analogues crowned were subjected to a compressive load with a 1-kN cell at a crosshead speed of 0.05 mm/min at 130° to the long axis until fracture occurred. Data were analyzed by Lillifors and Mann-Whitney tests. Mean failure loads for the groups were as follows: group I 1038.69 N (standard deviation ±243.52 N) and group II 1231.86 N (standard deviation ±368.76 N). Statistical tests showed significant difference between groups (p = 0.0010 < 0.01). Increasing the taper of internal coronal walls appears to enhance the fracture resistance of anterior maxillary teeth post and core reconstructed.
authors.affiliation: Department of Prosthodontics, School of Dentistry, Lebanese University, Beirut, Lebanon.
authors.forename: Loubna
authors.initials: L
authors.lastname: Shamseddine
authors.affiliation: Department of Prosthodontics, School of Dentistry, Lebanese University, Beirut, Lebanon.
authors.forename: Rita
authors.initials: R
authors.lastname: Eid
authors.affiliation: Department of Prosthodontics, School of Dentistry, Lebanese University, Beirut, Lebanon.
authors.forename: Fodda
authors.initials: F
authors.lastname: Homsy
authors.affiliation: Endodontist, Private Practice, Beirut, Lebanon.
authors.forename: Hasan
authors.initials: H
authors.lastname: Elhusseini
keywords: Cast post and core; adaptation; coronal taper; fracture resistance