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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Efeito da espessura e do material restaurador na resist?ncia ? fratura de facetas oclusais confeccionadas em CAD/CAM

Andrade, Jonas Pereira 19 January 2017 (has links)
Submitted by Caroline Xavier (caroline.xavier@pucrs.br) on 2017-06-26T14:49:22Z No. of bitstreams: 1 DIS_JONAS_PEREIRA_ANDRADE_PARCIAL.pdf: 141765 bytes, checksum: 99338991681873f9d3d7028d9e7cdfa9 (MD5) / Made available in DSpace on 2017-06-26T14:49:22Z (GMT). No. of bitstreams: 1 DIS_JONAS_PEREIRA_ANDRADE_PARCIAL.pdf: 141765 bytes, checksum: 99338991681873f9d3d7028d9e7cdfa9 (MD5) Previous issue date: 2017-01-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The aim of the study was to evaluate, in vitro, the fracture resistance of occlusal veneers, made by CAD/CAM, with Lava Ultimate, e.max CAD and Vita Enamic materials in thicknesses of 0.6 mm and 1.5 mm. Seventy third human sound molars were randomly divided into seven groups (n = 10) according to the variables material and thickness, with the sound teeth as control. The root of the teeth was embedded into a self-cured acrylic resin and the teeth were prepared to simulate advanced erosion of the occlusal surface. The occlusal veneers were made using CAD-CAM technology, being luted to the preparation with adhesive systems and resin cements. After storage in distilled water at 37 ?C for 24 h, the samples were submitted to mechanical cyclic loading (1 million cycles at 100 N load). Subsequently, the sound teeth and the samples with the occlusal veneers were submitted to the fracture resistance test in a universal testing machine with crosshead speed of 1 mm/min. The failures were classified as reparable and irreparable. According to two-way ANOVA, the interaction between material and thickness was significant (p=0.013). The highest fracture resistance was obtained for the e.max CAD in the thickness of 1.5 mm (4995 N), being statistically superior to the other groups (p <0.05). The lowest fracture resistance was obtained for Vita Enamic at 0.6 mm thickness (2973 N), not being significantly different from e.max CAD 0.6 mm (3067 N), Lava Ultimate 0.6 mm (3384 N), Vita Enamic 1.5 mm (3540 N) and Lava Ultimate 1.5 mm (3584 N) (p>0.05). According to one- way ANOVA, the fracture resistance of the sound teeth (3991 N) did not differ significantly from the teeth with occlusal veneers (p> 0.05). The failures were predominantly repairable, except for sound teeth and Lava Ultimate 1.5 mm. The Lava Ultimate, e.max CAD and Vita Enamic occlusal veneers, in the thicknesses of 0.6 mm and 1.5 mm, showed fracture resistance exceeding the maximum masticatory forces. / O objetivo do estudo foi avaliar, in vitro, a resist?ncia ? fratura de facetas oclusais, confeccionadas por CAD/CAM, com os materiais Lava Ultimate, e.max CAD e Vita Enamic nas espessuras de 0,6 mm e 1,5 mm. Setenta terceiros molares humanos h?gidos foram aleatoriamente divididos em sete grupos (n=10) de acordo com as vari?veis material e espessura, tendo os dentes h?gidos como controle. A raiz dos dentes foi inserida em resina acr?lica quimicamente ativada e os dentes receberam um preparo para simular eros?o avan?ada da superf?cie oclusal. As restaura??es oclusais foram confeccionadas por meio da tecnologia CAD-CAM, sendo cimentadas ao preparo com sistemas adesivos e cimentos resinosos. Ap?s armazenagem em ?gua destilada a 37 ?C por 24 h, as amostras foram submetidas ? ciclagem mec?nica (1 milh?o de ciclos com carga de 100 N). Na sequ?ncia, os dentes h?gidos e as amostras com as facetas oclusais foram submetidas ao ensaio de resist?ncia ? fratura em m?quina de ensaio universal com velocidade de 1 mm/min. As falhas foram classificadas em repar?veis e irrepar?veis. De acordo com ANOVA de duas vias, a intera??o entre material e espessura foi significativa (p=0,013). A maior resist?ncia ? fratura foi obtida para o e.max CAD na espessura de 1,5 mm (4995 N), sendo estatisticamente superior aos demais grupos (p<0,05). A menor resist?ncia ? fratura foi obtida para o Vita Enamic na espessura de 0,6 mm (2973 N), n?o diferindo estatisticamente do e.max CAD 0,6 mm (3067 N), Lava Ultimate 0,6 mm (3384 N), Vita Enamic 1,5 mm (3540 N) e Lava Ultimate 1,5 mm (3584 N) (p>0,05). De acordo com ANOVA de uma via, a resist?ncia ? fratura dos dentes h?gidos (3991 N) n?o diferiu estatisticamente dos dentes com facetas oclusais (p>0,05). As falhas foram predominantemente do tipo repar?vel, com exce??o dos dentes h?gidos e Lava Ultimate 1,5 mm. As facetas oclusais em Lava Ultimate, e.max CAD e Vita Enamic, nas espessuras de 0,6 mm e 1,5 mm, demonstraram resist?ncia ? fratura que excede as for?as mastigat?rias m?ximas.
2

Restaura??es endocrown produzidas em CAD/CAM : ensaio de carga m?xima de fratura e an?lise do padr?o de falha

Oliveira, P?mella Tomazi Godoy de 25 January 2018 (has links)
Submitted by PPG Odontologia (odontologia-pg@pucrs.br) on 2018-03-15T15:35:44Z No. of bitstreams: 1 P?MELLA_TOMAZI_GODOY_DE_OLIVEIRA_DIS.pdf: 1304084 bytes, checksum: caf3b44234731105c91e07d645c0f956 (MD5) / Rejected by Tatiana Lopes (tatiana.lopes@pucrs.br), reason: Devolvido porque o sum?rio do pdf est? desconfigurado. on 2018-03-28T11:41:16Z (GMT) / Submitted by PPG Odontologia (odontologia-pg@pucrs.br) on 2018-05-25T13:25:14Z No. of bitstreams: 1 P?MELLA_TOMAZI_GODOY_DE_OLIVEIRA_DIS.pdf: 1304084 bytes, checksum: caf3b44234731105c91e07d645c0f956 (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2018-06-11T16:26:07Z (GMT) No. of bitstreams: 1 P?MELLA_TOMAZI_GODOY_DE_OLIVEIRA_DIS.pdf: 1304084 bytes, checksum: caf3b44234731105c91e07d645c0f956 (MD5) / Made available in DSpace on 2018-06-11T16:31:30Z (GMT). No. of bitstreams: 1 P?MELLA_TOMAZI_GODOY_DE_OLIVEIRA_DIS.pdf: 1304084 bytes, checksum: caf3b44234731105c91e07d645c0f956 (MD5) Previous issue date: 2018-01-25 / Conselho Nacional de Pesquisa e Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Aims: to evaluate in vitro the fracture strength and failure pattern of endocrown restorations performed with Incoris TZI ceramics, Celta Duo and Empress CAD cemented on endodontically treated molars. Materials and methods: forty extracted sound molars were randomly distributed into 4 groups (n = 10). After being endodontically treated, they were restored with endocrowns carried out through the CEREC system with three different materials: Empress CAD (Ivoclar Vivadent), Celta Duo (Dentsply/Sirona) or Incoris TZI (Dentsply/Sirona). After, they were subjected to mechanical fatigue testing with vertical load application of 200N, totalling 500,000 cycles. Subsequently, the samples were submitted to the maximum fracture load under compressive force on the long axis of the tooth at cross-head speed of 1mm/min.. After the fracture strength testing the fracture patterns were evaluated being classified as repairable (cusps) or irreparable (pulp chamber floor rupture). Results: Sound: 4306Na ? 716.5; Incoris TZI: 3770NAb ? 846; Empress CAD: 1994Nc ? 498.5; Celta Duo: 3298Nb ? 1121. The Incoris TZI and Celta Duo presented the same proportion of irreparable fractures, 60%. The Empress Cad presented the same proportion for the repairable and irreparable fractures (50%). Conclusion: The Incoris TZI presented higher fracture strength, followed by Celta Duo, but did not differ statistically. In turn, the Empress CAD differed statistically from the others presenting lower fracture strength. The Incoris TZI and Celta Duo presented the same prognosis of failures with predominance of irreparable failures. / Objetivos: avaliar in vitro a resist?ncia ? fratura e o padr?o de falha de restaura??es endocrown realizadas com as cer?micas inCoris TZI, Celtra Duo e Empress CAD cimentadas sobre molares tratados endodonticamente. Materiais e m?todos: quarenta dentes molares h?gidos extra?dos foram distribu?dos aleatoriamente em 4 grupos (n=10). Ap?s serem endodonticamente tratados, foram restaurados com endocrowns realizadas atrav?s do sistema CEREC/InLab (Sirona) com tr?s diferentes materiais: Empress CAD (Ivoclar Vivadent), Celtra Duo (Dentsply/Sirona) ou inCoris TZI (Dentsply/Sirona). Ap?s, foram submetidos ? fadiga mec?nica com aplica??o de carga vertical de 200N, totalizando 500.000 ciclos. Posteriormente, foi testada a carga m?xima de fratura com for?a compressiva no longo eixo do dente sob velocidade de 1mm/min.. Ap?s o ensaio foram avaliados os padr?es de fratura e classificados em repar?veis (c?spides) ou irrepar?veis (assoalho da c?mara pulpar). Resultados: H?gidos: 4306Na ? 716,5; inCoris TZI: 3770Nab ? 846; Empress CAD:1994Nc ? 498,5; Celtra Duo: 3298Nb ? 1121. O grupo inCoris TZI e Celtra Duo apresentaram a mesma propor??o de fraturas irrepar?veis, 60%. O grupo Empress Cad apresentou a mesma propor??o para as fraturas repar?veis e irrepar?veis (50%). Conclus?o: O grupo inCoris TZI apresentou maior resist?ncia ? fratura, seguido do grupo Celtra Duo, mas n?o diferiram estatisticamente. Por sua vez, a cer?mica Empress CAD diferiu estatisticamente das demais apresentando menor valor de resist?ncia ? fratura. O grupo Incoris TZI e Celtra Duo apresentaram o mesmo progn?stico de falhas com predomin?ncia de falhas irrepar?veis.
3

Resist?ncia ? fratura de pr?teses unit?rias realizadas com diferentes materiais restauradores para CAD/CAM cimentadas sobre pilares s?lidos

Stona, Deborah 26 March 2018 (has links)
Submitted by PPG Odontologia (odontologia-pg@pucrs.br) on 2018-06-27T13:42:26Z No. of bitstreams: 1 DEBORAH_STONA_TES.pdf: 479572 bytes, checksum: 09946538cb3d70a32dd07508ec13bcce (MD5) / Rejected by Sheila Dias (sheila.dias@pucrs.br), reason: Trabalho devolvido devido constar no sum?rio o t?pico "Hip?teses", mas no corpo do trabalho n?o aparece, do t?pico "Objetivos" passa para "Materiais e m?todos" no arquivo PDF. on 2018-07-04T12:49:48Z (GMT) / Submitted by PPG Odontologia (odontologia-pg@pucrs.br) on 2018-07-19T10:52:46Z No. of bitstreams: 1 DEBORAH_STONA_TES.pdf: 842939 bytes, checksum: 8b8eda0f9181f560f275f85833a4faec (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-07-24T12:53:45Z (GMT) No. of bitstreams: 1 DEBORAH_STONA_TES.pdf: 842939 bytes, checksum: 8b8eda0f9181f560f275f85833a4faec (MD5) / Made available in DSpace on 2018-07-24T13:02:33Z (GMT). No. of bitstreams: 1 DEBORAH_STONA_TES.pdf: 842939 bytes, checksum: 8b8eda0f9181f560f275f85833a4faec (MD5) Previous issue date: 2018-03-26 / Conselho Nacional de Pesquisa e Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Aims: 1) to evaluate the fracture resistance of posterior full-contour crowns of lithium dissilicate, lithium silicate reinforced by zirconia or translucent zirconia cemented on solid abutments; 2) to evaluate if the presence of a zirconia coping can increase the fracture resistance of lithium dissilicate crowns compared to monolithic ceramics made in lithium dissilicate, lithium silicate reinforced by zirconia or translucent zirconia. Materials and methods: Forty RN (regular-neck, Straumann) implant analogs and 4.0 mm solid abutments (Straumann) were embedded in acrylic resin and divided into 5 groups (n = 8): 1) e.max CAD; 2) Celtra Duo; 3) Incoris zirconia TZI; 4) 0.6 mm zirconia coping + e.max CAD; 5) 0.3 mm zirconia coping + e.max CAD. After preparation of the specimens, they were subjected to mechanical fatigue testing with 200N and 500,000 cycles. Following, the samples were submitted to the fracture resistance testing. Results: the means in Newtons (N) were as follows: e.max CAD 210.6Na ? 1447; Celtra Duo 2026Nb ? 355.8; zirconia TZI 2850Nc ? 287.6; 0.6 mm coping + e.max CAD 851Nd ? 108.1; 0.3 mm coping + e.max CAD 980Nd ? 133. Conclusion: monolithic translucent zirconia crowns cemented on solid abutments showed the higher fracture resistance in comparison to lithium dissilicate (e.max CAD) and lithium silicate reinforced by zirconia (Celtra Duo). The use of a zirconia coping associated with lithium dissilicate does not promote superior fracture resistance than monolithic crowns regardless of the thickness of coping and veneering ceramics. / Objetivos: 1) Avaliar a resist?ncia ? fratura de coroas cer?micas de dissilicato de l?tio, silicato de l?tio refor?ada por zirc?nia e zirc?nia transl?cida cimentadas sobre pilares s?lidos; 2) Avaliar se a presen?a de um coping em zirc?nia pode aumentar a resist?ncia ? fratura de coroas de dissilicato de l?tio quando comparadas ?s cer?micas monol?ticas confeccionadas em dissilicato de l?tio, zirc?nia transl?cida ou silicato de l?tio refor?ada por zirc?nia cimentadas sobre pilares s?lidos. Materiais e m?todos: Quarenta an?logos de implantes RN (regular neck, Straumann) e pilares s?lidos 4.0mm (Straumann) foram inclu?dos em resina acr?lica e divididos em 5 grupos (n=8) os quais receberam as seguintes coroas prot?ticas cimentadas: 1) e.max CAD; 2) Celtra Duo; 3) zirc?nia Incoris TZI; 4) coping zirc?nia 0,6mm + e.max CAD; 5) coping zirc?nia 0,3mm + e.max CAD. Ap?s confec??o dos corpos de prova os mesmos foram submetidos ? fadiga mec?nica com carga de 200N e 500.000 ciclos. Na sequ?ncia foram submetidos ao ensaio de carga m?xima de carregamento. Resultados: as m?dias de resist?ncia ? fratura obtidas foram: e.max CAD 1447Na ? 210,6; Celtra Duo 2026Nb ? 355,8; zirc?nia TZI 2850Nc ? 287,6; coping 0,6mm + e.max CAD 851Nd ? 108,1; coping 0,3mm + e.max CAD 980Nd ? 133. Conclus?o: Coroas monol?ticas realizadas em zirc?nia transl?cida cimentadas sobre pilares s?lidos apresentaram a maior resist?ncia ? fratura quando comparadas ao dissilicato de l?tio (e.max CAD) e silicato de l?tio refor?ado por zirc?nia (Celtra Duo). O uso de um coping de zirc?nia associado ao dissilicato de l?tio n?o promove resist?ncia ? fratura superior as coroas monol?ticas independentemente das espessuras do coping e da cer?mica de cobertura.

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