Mechanical and physical properties of silorane and methacrylate-based composites

Made available in DSpace on 2019-09-12T16:53:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2013Objectives: This study measured the degree of conversion (DC), sorption, solubility and microhardness of methacrylate (Filtek Z250 and Filtek Z350XT) and silorane-based composites (Filtek P90). Methods: DC was measured using near infrared spectroscopy immediately and 24 h after the photoactivation. Sorption and solubility measurements were performed after 24 h, 4 weeks and 12 weeks of storage in water. Knoop microhardness was measured after 24 h and after thermal cycling. The data were statistically analyzed using ANOVA followed by Tukey's, Tamhane or paired t-tests (alpha = 0.05). Results: The DC for P90 (37.22 +/- 1.46) was significantly lower than the Z250 (71.44 +/- 1.66) and Z350 (71.76 +/- 2.84). Water sorption was highest in the Z250 and lowest in the P90. All the tested composites exhibited similar values after 24 h of immersion, and no significant differences were observed. No significant differences were observed between the solubilities of the P90 composite (12 weeks) and the Z250 or Z350 composites (4 weeks). KHN values were less elevated for the P90 composite and similar for the Z250 and Z350 composites. An effect of thermal cycling on KHN values was observed for all the composites (p < 0.001). Conclusions: Silorane produced the lowest DC and KHN values and exhibited lower water sorption and solubility compared to methacrylate- based composites. These differences suggest that silorane composites exhibit better hydrolytic stability after 3 months of water immersion compared to conventional methacrylate-based composites. Clinical significance: Silorane had higher hydrolytic stability after 3 months of water immersion than the methacrylate-based resins, despite the lower values of DC and KHN recorded. (c) 2013 Elsevier Ltd. All rights reserved.[Celerino de Moraes Porto, Isabel Cristina] Univ Fed Alagoas, Dept Restorat Dent, BR-57072970 Maceio, Alagoas, Brazil[Baggio de Aguiar, Flavio Henrique] Univ Estadual Campinas, Dept Restorat Dent, BR-13414903 Sao Paulo, Brazil[Brandt, William Cunha] Univ Santo Amaro, Dept Dent, BR-04829300 Sao Paulo, Brazil[Susy Liporoni, Priscila Christiane] Universidade de Taubaté (Unitau), Dept Restorat Dent, BR-12020340 Sao Paulo, Brazi

Dispositivo De Controle De FumaÇa E Uso Do Referido Dispositivo

DISPOSITIVO DE CONTROLE DE FUMAÇA E USO DO REFERIDO DISPOSITIVO. A presente invenção refere-se a um dispositivo de controle de fumaça de tabacaria utilizado em testes de pigméntação e depósitos tóxicos oriundos em substratos dentais e materiais odontológicos. Além disso, a presente invenção refere-se ao uso do referido dispositivo.BRPI1101465 (A2)G01N1/22BR2011PI01465G01N1/2

Bioinspired catechol chemistry for dentin remineralization: A new approach for the treatment of dentin hypersensitivity

Objective Dentin remineralization is of considerable clinical interest for dentin hypersensitivity and developing biomimetic analogs that can regulate hydroxyapatite (HAp) nucleation and growth remains a challenge. This study aimed to evaluate in vitro the potential for dentin remineralization using the following biomimetic in situ prepared poly(catechols): poly(dopamine), poly(DOPA), poly(caffeic acid) and a synthesized DOPA-peptide possessing collagen and calcium-binding domains (DOPA-Ahx-(Gly)3-(Glu)5). Methods Dentin samples were immersed in a freshly prepared phosphate-buffered saline (PBS) containing the respective catechol and laccase. After the reaction, they were immersed in calcium and phosphate remineralization solution, which was changed every day for 10 days. Samples of intact and demineralized dentin were used as control groups and kept in deionized water under the same experimental conditions. The remineralized dentin was characterized by scanning electron microscopy (SEM), Micro-energy dispersion X-ray fluorescence spectroscopy (μEDX) and X-ray diffraction (XRD). Results The application of different poly(catechols) and DOPA-peptide promoted crystal nucleation and the formation of HAp, which partially covered both the dentin surface and dentinal tubules walls. Significance By mimicking the role of charged non-collagenous proteins in vivo, polymers consisting of catechol groups showed the ability to modify demineralized dentin surface properties, promoting mineral formation. The use of poly(catechols) may be encouraged for the development of a therapeutic technique for dentin hypersensitivity