title: Fracture resistance of endodontically treated mandibular first molars with conservative access cavity and different restorative techniques: An in vitro study.
abstract: The aim was to investigate in vitro the fracture resistance (FR) of endodontically treated teeth (ETT) with conservative access cavity restored using various direct and indirect restorative materials and techniques. Seventy-two mandibular first molars were equally divided into six groups. Teeth in Group 1 were untreated (controls). In Groups 2, 3, 4, 5 and 6, teeth were restored with amalgam, composite resin, ceramic inlay, ceramic onlay and zirconium crown, respectively. A fracture test was performed on all teeth using a static load. Compared with other groups, teeth in Groups 3 (P < 0.05) and 6 (P < 0.05) had the highest FR values with no significant difference in-between them. Teeth in Group 4 had the lowest FR than other groups (P < 0.05). All restorative techniques tested led to a significant reduction in FR. It is necessary to consider type of fracture when evaluating fracture resistance of endodontically treated teeth. Crowned molars had the highest favourable fractures among the five treatment groups. Although the results of this in vitro study showed variations between tested techniques in ETT with a conservative access cavity, further long-term controlled clinical trials are required to confirm these in vitro findings.
authors.affiliation: Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Mohammad D
authors.initials: MD
authors.lastname: Al Amri
authors.affiliation: Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Sulieman
authors.initials: S
authors.lastname: Al-Johany
authors.affiliation: Department of Prosthetic Dental Sciences, College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
authors.forename: Haneef
authors.initials: H
authors.lastname: Sherfudhin
authors.affiliation: Department of Dentistry, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia.
authors.forename: Badar
authors.initials: B
authors.lastname: Al Shammari
authors.affiliation: Department of Prosthodontics, College of Dentistry, Hail University, Hail, Saudi Arabia.
authors.forename: Sami
authors.initials: S
authors.lastname: Al Mohefer
authors.affiliation: Prosthetic Dental Science Department, College of Dentistry, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Al Saloum
authors.affiliation: Prosthetic Dental Science Department, College of Dentistry, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia.
authors.forename: Hatem
authors.initials: H
authors.lastname: Al Qarni
mesh_terms: D003188:Composite Resins; D003793:Dental Restoration, Permanent; D003799:Dental Stress Analysis; D006801:Humans; D008963:Molar; D014082:Tooth Fractures; D019553:Tooth, Nonvital
chemical_list: D003188:Composite Resins
keywords: cuspal coverage; endodontically treated mandibular molar; failure mode; fracture resistance; restorative techniques