title: Do new matrix formulations improve resin composite resistance to degradation processes?
abstract: The aim of this study was to determine the degradation resistance of three new formulations-silorane-, Ormocer- and dimer-acid-based materials-and compare them to the traditional dimethacrylate-based materials. One silorane- (Filtek P90, P90), one Ormocer- (Ceram-X, CX), one dimer-acid- (N'Durance, ND) and two dimethacrylate-based (Filtek P60, P60; Tetric Ceram, TC) materials were investigated. Water sorption (Wsp) and solubility (Wsl) were determined after the materials were immersed in water for 28 days. Knoop hardness (KH) was determined before and after 24 h immersion in pure ethanol. The flexural-strength (FS) was determined by the bending test after one-week storage in a dry environment or after one-week immersion in pure ethanol. Data were submitted to analysis of variance (ANOVA) and Tukey's test (95%). The three new formulations showed lower Wsp than the dimethacrylate-based formulation. CX (0.50 ± 0.17%) and ND (0.72 ± 0.19%) exhibited the lowest Wsp, whereas P90 (0.02 ± 0.03%) and P60 (0.04 ± 0.03%) showed the lowest Wsl. All resins showed reduced Knoop hardness number (KHN) after ethanol immersion. P60 presented the lowest decrease in KH value (19 ± 5%). TC (48 ± 3%) and P90 (39 ± 9%) showed the highest KHN decrease after ethanol storage. The FS of CX, ND and TC were affected by ethanol storage. The new formulations did not improve the degradation resistance, as compared with the traditional methacrylate-based materials.
authors.affiliation: Universidade Veiga de Almeida, School of Dentistry, Clinic Department, Rio de JaneiroRJ, Brazil.
authors.forename: Andrea Soares Quirino da Silva
authors.initials: AS
authors.lastname: Fonseca
authors.forename: Kátia Maria da Fonseca
authors.initials: KM
authors.lastname: Gerhardt
authors.forename: Gisele Damiana da Silveira
authors.initials: GD
authors.lastname: Pereira
authors.forename: Mário Alexandre Coelho
authors.initials: MA
authors.lastname: Sinhoreti
authors.forename: Luis Felipe Jochims
authors.initials: LF
authors.lastname: Schneider
mesh_terms: D000704:Analysis of Variance; D003188:Composite Resins / Q000737:chemistry*; D000431:Ethanol / Q000737:chemistry; D006245:Hardness Tests; D007101:Immersion; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry*; D063225:Organically Modified Ceramics / Q000737:chemistry*; D058105:Polymerization; D062047:Silorane Resins / Q000737:chemistry*; D012995:Solubility; D013499:Surface Properties; D013997:Time Factors; D014867:Water / Q000737:chemistry
chemical_list: C520091:CeramX; D003188:Composite Resins; C438835:Filtek P60 Composite Resin; D008689:Methacrylates; C551012:N'Durance composite resin; D063225:Organically Modified Ceramics; D062047:Silorane Resins; C121818:Tetric ceram; C544925:filtek P90; D014867:Water; D000431:Ethanol