Submitted by PPG Odontologia (odontologia-pg@pucrs.br) on 2018-03-15T18:05:08Z No. of bitstreams: 1 LEONARDO_DE_CESERO_TES.pdf: 930355 bytes, checksum: 2c97f9568abe8fdc237aa889661c8a3c (MD5) / Approved for entry into archive by Tatiana Lopes (tatiana.lopes@pucrs.br) on 2018-03-27T12:23:49Z (GMT) No. of bitstreams: 1 LEONARDO_DE_CESERO_TES.pdf: 930355 bytes, checksum: 2c97f9568abe8fdc237aa889661c8a3c (MD5) / Made available in DSpace on 2018-03-27T12:27:51Z (GMT). No. of bitstreams: 1 LEONARDO_DE_CESERO_TES.pdf: 930355 bytes, checksum: 2c97f9568abe8fdc237aa889661c8a3c (MD5) Previous issue date: 2017-11-24 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Conselho Nacional de Pesquisa e Desenvolvimento Cient?fico e Tecnol?gico - CNPq / The current applications of nanotechnology in dentistry include adhesive systems and composite resins, but they are still quite limited in dental materials. Dental stone is a widely used material, and the incorporation of silica nanoparticles is still unexplored. The purpose of this study is to evaluate the behavior of the mechanical properties of dental stones with the addition of silica nanoparticles at different concentrations. A total of 180 samples were prepared, 90 for each dental stone (Durone and Fuji Rock). For the control group (CG), no silica particles were added, while test group 1 (TG1) had silica nanoparticles added to 1% by weight, and test group 2 (TG2) had silica nanoparticles added to 5% by weight. The roughness, diametral tensile strength (DTS) and compressive strength were measured 24 hours after the start of spatulation. The mean roughness values for Durone were CG= 0,55, TG1= 0,36 and TG2= 0,28 ?m and for Fuji Rock were CG= 0,47, TG1= 0,31 and TG2= 0,35 ?m. The mean DTS values for Durone were CG= 6,03, TG1= 5,17 and TG2= 5,02 MPa and for Fuji Rock were CG= 6,41, TG1= 5,23 and TG2= 4,56 MPa. The mean compressive strength values for Durone were CG= 35,44, TG1= 32,70 and TG2= 32,44 MPa and for Fuji Rock were CG= 42,97, TG1= 31,22 and TG2= 29,86 MPa. Surface roughness was statistically lower for the Durone and Fuji Rock stones (p< 0,001) when silica nanoparticles were added. For DTS and compressive strength, the addition of silica nanoparticles did not lead to statistically better results when compared to the control groups (p> 0,05). / A nanotecnologia na Odontologia est? presente nos sistemas adesivos e nas resinas compostas, sendo sua aplica??o ainda bastante limitada nos materiais dent?rios. O gesso odontol?gico ? um material amplamente utilizado e a incorpora??o de nanopart?culas de s?lica ? desconhecida. O objetivo do estudo ? avaliar o comportamento das propriedades mec?nicas dos gessos odontol?gicos a partir da adi??o de nanopart?culas de s?lica em diferentes concentra??es. Foram confeccionadas 180 amostras, sendo 90 para cada gesso (Durone e Fuji Rock). No grupo controle (GC) n?o foram adicionadas part?culas, no grupo teste 1 (GT1) foram adicionadas 1% em peso e o grupo teste 2 (GT2) recebeu 5% em peso de nanopart?culas de s?lica. Os testes de rugosidade, tra??o diametral (DTS) e compress?o foram realizados ap?s 24 horas do in?cio da espatula??o. Os valores m?dios de rugosidade para o Durone foram de GC= 0,55, GT1= 0,36 e GT2= 0,28 ?m e para o Fuji Rock foram de GC= 0,47, GT1= 0,31 e GT2= 0,35 ?m. Para DTS foram de GC= 6,03, GT1= 5,17 e GT2= 5,02 MPa para o Durone e para o Fuji Rock foram de GC= 6,41, GT1= 5,23 e GT2= 4,56 MPa. Para compress?o foram de GC= 35,44, GT1= 32,70 e GT2= 32,44 MPa para o Durone e para o Fuji Rock foram de GC= 42,97, GT1= 31,22 e GT2= 29,86 MPa. Houve uma menor rugosidade superficial estatisticamente para os gessos Durone e Fuji Rock (p< 0,001) quando adicionadas nanopart?culas de s?lica. Para a DTS e compress?o n?o houve estatisticamente resultados melhores quando adicionadas nanopart?culas de s?lica em compara??o aos grupos controles (p> 0,05).