title: Influence of different load application devices on fracture resistance of restored premolars.
abstract: This in vitro study analyzed the effect of different load application devices on fracture resistance and failure mode of maxillary premolars restored with composite resin. Sixty human maxillary premolars received standardized mesio-occluso-distal cavity preparations and were restored with composite resin. The specimens were randomly divided into 6 groups (n=10). Compressive loading was applied using 6 different metallic devices: S2: 2-mm sphere; S6: 6-mm sphere; C2: 2-mm cylinder; C6: 6-mm cylinder; WS: wedge shape device; and MAT: individualized metallic antagonist tooth. Data were analyzed statistically using one-way ANOVA and Tukey's test (α=0.05). The failure mode was recorded based on the 4 sequential levels. Statistical analysis revealed that WS presented significantly higher fracture resistance than S6 and C6. No significant difference was found among MAT, C2, S2 and S6. Sphere and cylinder with 6 mm were similar, with the lowest values of all groups. MAT presented the least number of catastrophic failures while C2, S2 and WS presented the highest. The type of load application device influences significantly the behavior of the teeth-restoration complex during mechanical fracture resistance test.
authors.affiliation: Biomechanical Research Group, Department of Operative Dentistry and Dental Materials, Dental School, Federal University of Uberlândia, MG, Brazil.
authors.forename: Gisele Rodrigues da
authors.initials: GR
authors.lastname: Silva
authors.forename: Natércia Rezende da
authors.initials: NR
authors.lastname: Silva
authors.forename: Paulo Vinícius
authors.initials: PV
authors.lastname: Soares
authors.forename: Ana Rosa
authors.initials: AR
authors.lastname: Costa
authors.forename: Alfredo Júlio
authors.initials: AJ
authors.lastname: Fernandes-Neto
authors.forename: Carlos José
authors.initials: CJ
authors.lastname: Soares
mesh_terms: D000704:Analysis of Variance; D001641:Bicuspid; D003188:Composite Resins / Q000737:chemistry*; D003793:Dental Restoration, Permanent; D019544:Equipment Failure Analysis / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D008422:Materials Testing / Q000295:instrumentation*; D014082:Tooth Fractures
chemical_list: D003188:Composite Resins