title: Mechanical properties of composites as functions of the syringe storage temperature and energy dose.
abstract: OBJECTIVE
  To investigate the mechanical properties of different classifications of composites indicated for posterior application as functions of the storage condition and of the energy dose.
  
  
  METHODS
  Specimens (8 x 2 x 2 mm) were obtained according to the factors: I) Composites (3M ESPE): Filtek P60, Filtek Z350XT, and Filtek Silorane; II) Syringe storage conditions: room temperature, aged, oven, refrigerator, and freezer; and III) Energy dose: 24 J/cm(2) and 48 J/cm(2). After photoactivation, the specimens were stored at 37 ºC for 24 h. After storage, a three-point bending test was carried out in a universal testing machine at 0.5 mm/min. Flexural strength (S) and flexural modulus (E) were calculated. Data were analyzed by three-way ANOVA and Tukey's test (α = 0.05).
  
  
  RESULTS
  Different storage conditions significantly affected the silorane composite for S; conversely, no effects were noted in terms of E. The accelerated aging protocol significantly increased the S of Filtek P60 and Filtek Silorane, whereas storage in the oven significantly decreased the S for all of the composites tested. Filtek P60 was the only composite not affected by the lower storage temperatures tested for S, whereas for the silorane this parameter was impacted at the same conditions. The factor "dose" was not statistically significant.
  
  
  CONCLUSIONS
  The syringe storage at different temperature conditions proved to influence mostly the flexural strength, a clinically important characteristic considering the posterior indication of the materials tested. The silorane composite should not be stored at lower temperatures.
authors: Biomaterials Research Group, Universidade Anhanguera de São Paulo, São Paulo, SP, Brazil.
authors: Fernanda Oliveira
authors: FO
authors: Chaves
authors: Biomaterials Research Group, Universidade Anhanguera de São Paulo, São Paulo, SP, Brazil.
authors: Natália Coelho de
authors: NC
authors: Farias
authors: Biomaterials Research Group, Universidade Anhanguera de São Paulo, São Paulo, SP, Brazil.
authors: Luciano Marcelo de Mello
authors: LM
authors: Medeiros
authors: Biomaterials Research Group, Universidade Anhanguera de São Paulo, São Paulo, SP, Brazil.
authors: Roberta Caroline Bruschi
authors: RC
authors: Alonso
authors: Biomaterials Research Group, Universidade Anhanguera de São Paulo, São Paulo, SP, Brazil.
authors: Vinicius
authors: V
authors: Di Hipólito
authors: Biomaterials Research Group, Universidade Anhanguera de São Paulo, São Paulo, SP, Brazil.
authors: Paulo Henrique Perlatti
authors: PH
authors: D'Alpino
mesh_terms: D000704:Analysis of Variance; D003188:Composite Resins / Q000737:chemistry* / Q000528:radiation effects*; D055117:Curing Lights, Dental; D055119:Elastic Modulus; D008422:Materials Testing; D058105:Polymerization; D011829:Radiation Dosage; D062047:Silorane Resins / Q000737:chemistry; D013314:Stress, Mechanical; D013594:Syringes; D013696:Temperature; D013997:Time Factors
chemical_list: D003188:Composite Resins; C438835:Filtek P60 Composite Resin; D062047:Silorane Resins; C533204:filtek Z350; C555513:silorane composite resin