RESUMO
The paper presents the results of laboratory tests of base thermoplastic materials Acry F711 and Flexi N512 in comparison with the traditional acrylic base material Ftoracs to study their deformational properties when loaded by repetitive forces close to the functional chewing loads.
Assuntos
Materiais Dentários , Prótese Parcial Removível , Temperatura Alta , Humanos , Laboratórios Odontológicos , Mastigação , Teste de Materiais , Metacrilatos , PolímerosRESUMO
The paper presents laboratory model for evaluation of the effectiveness of tooth whitening agents on pure and technical hydroxyapatite (HAP) samples. HAP samples were exposed in distilled water, and colour measurements were taken after coloration in tea extract and using of "Blend-a-med delicate bleaching" ("Procter & Gamble", Germany) toothpaste. The proposed laboratory model allows imitating discoloration by food dye (tea) and measure the whitening toothpaste effect by significant change in colour characteristics in the CIE L*a*b* system.
Assuntos
Durapatita/química , Modelos Dentários , Clareadores Dentários/administração & dosagem , Clareamento Dental , Humanos , Laboratórios , Clareadores Dentários/química , Resultado do TratamentoRESUMO
Results of laboratory tests of polyurethane based material "Pentalur" conducted to determine its mechanical properties proved the material to meet basic requirements for removable dentures materials. The introduction of simple poluethers with certain molecular weight as well as 1,4-butanediol allows varying polyurethane properties in a fairly wide range. This range of polyurethane mechanical properties along with good biocompatibility opens new possibilities in creation of removable dentures with improved functional properties as well as maxillofacial prosthesis.
Assuntos
Bases de Dentadura , Poliuretanos/química , Ácido Succínico/química , Módulo de ElasticidadeAssuntos
Cor , Resinas Compostas , Nanocompostos , Clareadores Dentários , Clareamento Dental , HumanosRESUMO
Results of the study of physical-chemical properties of new endodontic sealant Acrosil (Septodent, France) were presented. The results of all used in the experiment tests corresponded with the existing standards. The received data were compared with the corresponding tests of endodontic sealant AH-Plus (Dentsply, DeTrey, Germany) and were analyzed statistically. The comparison showed higher adhesion properties of Acrosil.
Assuntos
Teste de Materiais , Materiais Restauradores do Canal Radicular/química , Obturação do Canal Radicular , Materiais Restauradores do Canal Radicular/classificação , UltrassomRESUMO
Gingival prosthetics effectively eliminates esthetic and phonetic disturbances in cases of pronounced gingival recession. Technology for making elastic gingival prosthetic devices of domestically produced siloxane elastomer composition with microwave siloxane vulcanization is described as well as the technique for making combined gingival prosthetics of siloxane composition and colorless plastic.
Assuntos
Gengiva , Prótese Periodontal , Elastômeros de Silicone , Siloxanas , Planejamento de Prótese Dentária , Elasticidade , Estética Dentária , Humanos , Modelos DentáriosRESUMO
Adhesive strength of gutta-percha stems connection to the root channel walls was evaluated. The pressure on dental root channel walls during tooth filling by the lateral condensation method was evaluated. The study was carried out on an Instron device by the pulling out method. The study showed that for stems Nos. 15-30 the retention strength in the root channel was about 2-fold higher than for stems Nos. 35-45. The results indicate that the value of stem pressure on root channel walls during tooth filling by the lateral condensation method can be considered critical with regard to the strength of the dental root proper.
Assuntos
Adaptação Marginal Dentária/normas , Obturação do Canal Radicular/métodos , Adesividade , Adesivos/química , Adesivos/uso terapêutico , Guta-Percha/química , Guta-Percha/uso terapêutico , Humanos , Pressão , Obturação do Canal Radicular/normas , Resultado do TratamentoRESUMO
Wear resistance parameters were evaluated for 5 materials used for masticatory teeth filling. The study was carried out on an Uism-1 device for evaluation of abrasion resistance of dental materials by the friction method during circular movement of a premolar (removed for orthodontic indications) along the surface of reference material. Similar abrasion resistance in the material-tooth pair was detected for 4 materials: Herculite XRV (Kerr-Sybron), Unirest (Stomadent), Dyract AP (Dentsply/De Trey), and Tytin amalgams (S.S. White); the parameters of wear differed. The highest wear of material paralleled by high tooth abrasion were detected for Filtek P-60 (3M/Dental) material.
Assuntos
Resinas Compostas/química , Dente Pré-Molar , Restauração Dentária Permanente , Fricção , Humanos , Teste de Materiais/instrumentaçãoRESUMO
Marginal leakage in class I cavities restored with chemically hardened resin composites (Talan, Charisma PPF, Esterfill) and adhesive strength were studied in vitro. The results indicate the least marginal leakage and best adhesive strength of the Talan composite.
Assuntos
Resinas Compostas/química , AdesividadeRESUMO
Pressing problems in bleaching devital teeth are discussed. Bleaching Endoperox and Brilliant were studied in vitro. For evaluating the safety of devital teeth bleaching, the microhardness of dental tissues was evaluated after intra-crown bleaching. The most significant changes in microhardness were observed in the coat dentin area.
Assuntos
Clareamento Dental/efeitos adversos , Descoloração de Dente/terapia , Dente não Vital/terapia , Boratos/uso terapêutico , Peróxido de Carbamida , Combinação de Medicamentos , Humanos , Peróxido de Hidrogênio/uso terapêutico , Técnicas In Vitro , Peróxidos/uso terapêutico , Ureia/análogos & derivados , Ureia/uso terapêuticoRESUMO
Comparative colorimetric evaluation of shades and translucency of different samples, fabricated from Filtec Z-250, Unirest, Dyract AP and Vitremer, shows, that differences in their compositions and industrial technologies result to great differences between the shades of the same number of Vita Shade Guide. The less color stability after long term action by foods media to the samples was found for the glass ionomer cement. The best color stability was found for composites, partially, for Unirest. All of these, let us conclude, that the main changes, not only in shades, but in translucency of materials, as a result the action of model media, take place at the early periods (the first month). Usually, the most main changes in restorative materials take place in this period of beginning and connect with the end of setting processes and achieving the balances between water absorption and solubility.
Assuntos
Cor/normas , Resinas Compostas/química , Cimentos de Ionômeros de Vidro/química , Colorimetria/instrumentação , Restauração Dentária Permanente , Estética Dentária , Técnicas In VitroRESUMO
Some physical and mechanical properties of the new acrylic material ACR-MW for microwave polymerization, the base material Etacryl-02 ("Stoma", Ukraine) and their analogue Acron MC (GC Lab Technologies Inc., Japan). The findings suggest that the new special denture base material ACR-MW for rapid microwave polymerization (3 min at 100%) possesses the highest bending strength with lower water absorption and solubility. The properties of ACR-MW meet the requirements of ISO 1567.
Assuntos
Resinas Acrílicas/química , Materiais Dentários/química , Micro-Ondas , Propriedades de SuperfícieRESUMO
Adhesive strength of combination of several liner and filling materials used for filling dental root channels was studied and the marginal permeability of root channel from the side of the crown was evaluated after filling with several pairs of pad and filling materials. Filling of root channels with gutta percha pins with hermetics did not deteriorate the strength of adhesion of BaseLine pad to the bottom of the cavity, while filling with Forfenane decreased the adhesion of this pad material 3-fold. Use of Belocor polycarboxylate cement for pad essentially deteriorated the adhesive strength of the pad irrespective of the filling material.
Assuntos
Guta-Percha/química , Cimento de Policarboxilato/química , Obturação do Canal Radicular/métodos , Adesividade , Humanos , Técnicas In VitroRESUMO
The paper outlines the specific features of using microwave technologies in dental and eye prostheses designed in Russia in 1992-1998. Thermal, microwave, and combined polymerizations of plastic materials used in prosthesis are compared. A Denta microwave unit is presented, which realizes a combined microwave technology.
Assuntos
Prótese Dentária , Olho Artificial , Micro-Ondas , Temperatura Alta , Humanos , Modelos Teóricos , PolímerosRESUMO
The strength and color stability of various composites of photo- and chemical consolidation is assessed by laboratory methods. The class of a material is the most essential factor affecting the above characteristics. The macrofilled and hybrid materials showed the best adhesive and bending strength. The method of consolidation does not notably affect the studied characteristics.