title: Strengthening effect of horizontally placed fiberglass posts in endodontically-treated teeth restored with direct resin composite.
abstract: OBJECTIVE
  To assess the fracture strength of cavity preparations, directly restored with resin composite, with and without the presence of fiberglass posts with different diameters.
  
  
  METHODS
  84 extracted third molars were embedded in acrylic resin and divided into six groups (n = 14 per group): healthy (H); cavity preparation (P); cavity preparation + endodontic treatment (PE); PE + resin composite (R); PE + R + 2 horizontally transfixed fiberglass posts 1.1 mm in diameter (PERP1); PE + R + 2 fiberglass posts 1.5 mm in diameter (PERP2). The MOD cavity preparations were standardized with their width corresponding to 2/3 of the buccolingual distance and occlusogingival depth of 4 mm, with 2 mm remaining above the cemento-enamel junction. Endodontic treatments were performed in the PE, R, PERP1 and PERP2 groups. The buccal surface received two demarcations to create orifices for placement of the PERP1 and PERP2 posts. Once the fiberglass posts were placed, the teeth were restored with resin composite. In group R, only resin composite was used. After 24 hours, the teeth were subjected to the fracture toughness test on a universal testing machine. A 10 KN load cell and crosshead speed of 1 mm/minute was used until fracture occurred. After testing, the teeth were inspected for the type of fracture classified as: pulpal floor fracture (AP) or cuspal fracture (CP).
  
  
  RESULTS
  The data were subjected to ANOVA and Tukey's test (P < 0.05%), demonstrating a statistical difference between groups: H 3830NA; P 778ND; PE 572.93ND; R 1782NC; PERP1 2988NB; PERP2 3100NAB. The fracture pattern was similar between the tested groups, showing 50% of fracture for cusps and pulpal floor.
authors.forename: Fernando José
authors.initials: FJ
authors.lastname: Favero
authors.forename: Tiago André Fontoura
authors.initials: TA
authors.lastname: De Melo
authors.forename: Deborah
authors.initials: D
authors.lastname: Stona
authors.forename: Eduardo Gonçalves
authors.initials: EG
authors.lastname: Mota
authors.forename: Ana Maria
authors.initials: AM
authors.lastname: Spohr
authors.forename: Luiz Henrique
authors.initials: LH
authors.lastname: Burnett
mesh_terms: D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003737:Dental Cavity Preparation / Q000379:methods; D003764:Dental Materials / Q000737:chemistry*; D017267:Dental Prosthesis Design; D003782:Dental Pulp / Q000293:injuries; D003793:Dental Restoration, Permanent / Q000379:methods; D003799:Dental Stress Analysis / Q000295:instrumentation; D005898:Glass / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D011176:Post and Core Technique / Q000295:instrumentation*; D018915:Root Canal Preparation / Q000379:methods; D013314:Stress, Mechanical; D013997:Time Factors; D019228:Tooth Crown / Q000293:injuries; D014082:Tooth Fractures / Q000503:physiopathology; D019553:Tooth, Nonvital / Q000628:therapy*
chemical_list: D003188:Composite Resins; D003764:Dental Materials; C009753:fiberglass