title: Starch tubing: an alternative method to build up microshear bond test specimens.
abstract: OBJECTIVE
  To evaluate an alternative device using starch tubes to build up resin composite specimens for microshear bond tests.
  
  
  METHODS
  Twenty human molars were selected and sectioned mesiodistally to obtain two sections. The teeth were randomly divided into 4 groups (n = 10) according to the adhesive system - a two-step etch-and-rinse adhesive (Adper Single Bond) and a two-step self-etching adhesive (Clearfil SE Bond) - and the type of tube, starch or polyethylene. The tubes were evaluated under a stereomicroscope at 25X magnification to observe the variation in internal diameter. The resin composite was bonded to flat enamel surfaces using one of the adhesive systems and tube types. After 24 h storage in distilled water, the microshear bond strength (µSBS) was determined and the fracture pattern was analyzed under a stereomicroscope (400X magnification). The microshear bond strength values were subjected to two-way ANOVA. The chi-square test was used to compare pre-test failures and fracture patterns between the groups (p < 0.05).
  
  
  RESULTS
  The type of tube, the adhesive system, and their interaction did not influence the bond strength values (p = 0.062, p = 0.122, and p = 0.301, respectively). No significant differences were observed for pre-test failures or fracture patterns (p = 0.320 and p = 0.561, respectively).
  
  
  CONCLUSIONS
  Using starch tubes is an alternative to build up composite resin specimens for microshear bond strength testing with the two tested adhesive systems.
authors.affiliation: Department of Orthodontics and Pediatric, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Tamara Kerber
authors.initials: TK
authors.lastname: Tedesco
authors.forename: Anelise Fernandes
authors.initials: AF
authors.lastname: Montagner
authors.forename: Jovito Adiel
authors.initials: JA
authors.lastname: Skupien
authors.forename: Fabio Z M
authors.initials: FZ
authors.lastname: Soares
authors.forename: Alexandre Henrique
authors.initials: AH
authors.lastname: Susin
authors.forename: Rachel de Oliveira
authors.initials: RO
authors.lastname: Rocha
mesh_terms: D000704:Analysis of Variance; D016009:Chi-Square Distribution; D003188:Composite Resins; D001840:Dental Bonding / Q000379:methods; D003743:Dental Enamel; D003799:Dental Stress Analysis / Q000295:instrumentation*; D006801:Humans; D008422:Materials Testing; D011095:Polyethylenes; D019279:Resin Cements; D033081:Shear Strength; D013213:Starch; D018709:Statistics, Nonparametric
chemical_list: D003188:Composite Resins; D011095:Polyethylenes; D019279:Resin Cements; D013213:Starch