title: Effect of fractured or sectioned fragments on the fracture strength of different reattachment techniques.
abstract: This study evaluated the effect of fractured or sectioned fragments on the fracture strength recovery of four techniques used for reattachment and resin composite buildups. Ninety-one sound, permanent lower central incisors were used. Half the teeth were fractured in the incisal-proximal edge; the other half had the incisal-proximal edge sectioned by a diamond saw. Teeth from each half were randomly divided into five techniques: 1) bonded only; 2) chamfer; 3) over-contour; 4) internal dentinal groove and 5) resin composite buildup. An adhesive system and dual cure resin cement were employed for the reattachment. Restored teeth were subjected to load in a specific point on the buccal surface. Based on the fracture strength of sound teeth, a fracture strength recovery was calculated for each tooth. A one-way ANOVA and Tukey's test (alpha=0.05) were used to evaluate differences between the techniques for each method of obtaining fragments. The fracture strength recovery of similar techniques was evaluated by a Student t-test (alpha=0.05). No differences could be detected among reattachment techniques when fragments were obtained by sectioning. In groups where the fragments were fractured, Techniques 3 and 4 showed the highest fracture strength recovery. The resin composite buildup provided fracture strength recovery similar to intact teeth regardless the way fragments were obtained.
authors.affiliation: Dental Materials and Operative Dentistry, School of Dentistry, University of Oeste de Santa Catarina, Joaçaba, SC, Brazil. aloguercio@hotmail.com
authors.forename: Alessandro Dourado
authors.initials: AD
authors.lastname: Loguercio
authors.forename: Janice
authors.initials: J
authors.lastname: Mengarda
authors.forename: Roberto
authors.initials: R
authors.lastname: Amaral
authors.forename: Alexandra
authors.initials: A
authors.lastname: Kraul
authors.forename: Alessandra
authors.initials: A
authors.lastname: Reis
mesh_terms: D000704:Analysis of Variance; D003188:Composite Resins / Q000627:therapeutic use; D001840:Dental Bonding; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis / Q000379:methods; D006801:Humans; D007180:Incisor; D018709:Statistics, Nonparametric; D019228:Tooth Crown / Q000293:injuries; D014082:Tooth Fractures / Q000628:therapy*; D019246:Tooth Preparation / Q000379:methods
chemical_list: D003188:Composite Resins