title: Degradation resistance of ormocer- and dimethacrylate-based matrices with different filler contents.
abstract: OBJECTIVE
  To investigate the influence of matrix and filler content on degradation resistance of an experimental pure-ormocer and an dimethacrylate-based composite derived from a commercially available material.
  
  
  METHODS
  A dimethacrylate- Grandio (GR) and a model pure ormocer-based-matrix ORMOCER (ORM) were used. Each material had three different types according to their filler content (% w/w): regular (87% and 86%), flowable (80% and 79%) and fissure sealer (70% and 69%) for GR and ORM respectively. Disc-shaped (1 mm thickness×10 mm diameter) samples were prepared for each material (n=6). Water sorption and solubility tests were adapted from ISO4049. To evaluate porosity, specimens were scanned at a resolution of 19.4 μm and 3D reconstructions were made. The volume ratio of pores in the specimens were calculated and expressed as percentages. The results were submitted to 2-way ANOVA (factors: matrix and filler content) and Tukey post-hoc statistic test (p=0.05).
  
  
  RESULTS
  Filler content influenced the water sorption for the ormocer-matrix and the water solubility for the dimethacrylates. ORMOCER regular was a less porous material compared to flowable and sealer formulations. On the other hand, the filler content had no effect on porosity for Grandio.
  
  
  CONCLUSIONS
  Modifications made in the pure ormocer-matrix formulation were not significantly important to produce a more water-stable material compared to the dimethacrylate-matrix composite materials.
authors.affiliation: School of Dentistry, Federal Fluminense University, Niterói, Brazil. lara_cavalcante@yahoo.com.br
authors.forename: Larissa Maria
authors.initials: LM
authors.lastname: Cavalcante
authors.forename: Luis Felipe Jochims
authors.initials: LF
authors.lastname: Schneider
authors.forename: Mohammad
authors.initials: M
authors.lastname: Hammad
authors.forename: David C
authors.initials: DC
authors.lastname: Watts
authors.forename: Nick
authors.initials: N
authors.lastname: Silikas
mesh_terms: D000042:Absorption; D000704:Analysis of Variance; D002516:Ceramics / Q000737:chemistry*; D003188:Composite Resins / Q000737:chemistry*; D006868:Hydrolysis; D008422:Materials Testing; D063225:Organically Modified Ceramics; D010316:Particle Size; D010895:Pit and Fissure Sealants; D016062:Porosity; D012821:Silanes / Q000737:chemistry; D012995:Solubility; D018709:Statistics, Nonparametric; D014867:Water
chemical_list: D003188:Composite Resins; C509998:Grandio; D063225:Organically Modified Ceramics; D010895:Pit and Fissure Sealants; D012821:Silanes; D014867:Water