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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.
91

Influência do cimento endodôntico e agente cimentante na retenção de pinos de fibra / Influence of endodontic sealer and luting cements on fiber posts bond strength

Nascimento, Angela Longo do January 2015 (has links)
Objetivos: O objetivo desse estudo foi avaliar a influência da presença do cimento endodôntico e agente cimentante na retenção de pinos de fibra. Metodologia: Cento e oitenta dentes extraídos foram divididos em dois grupos (n=90) de acordo com a forma de obturação: condensação lateral ou obturação apenas do terço apical. Cada um destes grupos foi subdividido em três grupos (n=10) de acordo com o cimento utilizado para a obturação (AH Plus, Endofil e MTAFillapex). Os cimentos foram manipulados e acrescidos de corante Rodamina B na proporção de 0,1% para possibilitar visualização através da microscopia confocal a laser. Quinze dias após a obturação, estes dentes foram preparados para a cimentação do pino de fibra (Reforpost Angelus) com os cimentos RelyX ARC (ARC), U200 e Gold Label Cement Lining (GL). Os dentes foram seccionados transversalmente para obtenção de fatias com 1mm de espessura e submetidos à microscopia confocal a laser para verificar a penetração do cimento endodôntico nos túbulos dentinários, posteriormente ao teste de push-out. O padrão de falha foi analisado em esteromicroscópio e imagens representativas foram feitas em microscopia eletrônica de varredura. Os valores de resistência de união em MPa de acordo com a técnica de obturação foram analisados pelo teste de Mann-Whitney. Os valores de resistência de união dos grupos experimentais foram analisados pelo teste de Kruskal-Wallis e post hoc de Dunn, com nível de significância de 5%. Resultados: Não houve diferença significativa entre as formas de obturação (P>0,05). O tipo de cimento obturador influenciou a resistência de união, e o cimento MTA-Fillapex apresentou valores de resistência de união significativamente inferiores ao AH Plus (P<0,05). Os grupos que utilizaram GL para cimentação dos pinos de fibra de vidro apresentaram valores para o teste de push-out superiores aos cimentos resinosos (P < 0,05). Não houve diferença significativa entre o ARC e o U200 (P > 0,05). Conclusões: Valores de resistência de união mais altos foram observados quando os pinos de fibra foram cimentados com cimento GL . Os padrões de falha mistas foram predominantes e ocorreram em todos os grupos experimentais. / Aim: Evaluate the influence of the endodontic sealer and luting cements on the fiber post bond strength. Methodology: One hundred and eighty extracted teeth were assigned to two groups, considering the root filling technique: lateral condensation or root filling of the apical portion only. Each group were divided into three groups (n=10) according the sealer applied (AH Plus, Endofill or MTA-Fillapex). Rhodamine B was mixed to the sealer in a ratio of 0,1% in order to provide adequate fluorescence assessed by confocal microscopy. Fifty days after root canal filling, post-space preparation were performed with luting cements: RelyX ARC (ARC), U200 and Gold Label Cement Lining (GL). One thick slices were produced and submitted to confocal miscroscopy to assessed sealer penetration into dentinal tubules, and than submitted to push-out test. The failure modes were analysed in stereomicroscope and representative images were obtained in a scanning electron microscope. Push-out strength values of the root filling technique were analyzed using Mann-Whitney test. Push-out strength values of experimental groups were analysed using Kruskal-Wallis and Dunn´s post hoc test at significance level 5%. Results: No significant difference was observed (P>0.05) between the root filling technique. The type of endodontic sealer influenced the push-out bond strength, and MTA-Fillapex sealers presents lower bond strength values than AH Plus (P<0.05). Fiber posts cemented with GL presented higher push-out bond strength than resin cements (P<0.05). There was no significant difference between ARC and U200 (P>0.05). Conclusions: Fiber posts showed higher bond strength values when cemented with GL. Mixed failures were predominant and occurred in all the experimental groups.
92

Efeitos do laser de CO2 na desmineralização do esmalte ao redor de braquetes ortodonticos / Effect of CO2 laser in the enamel demineralization around orthodontic brackets

Souza-e-Silva, Cintia Maria de 16 September 2008 (has links)
Orientador: Marines Nobre dos Santos Uchoa / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-11T22:53:41Z (GMT). No. of bitstreams: 1 Souza-e-Silva_CintiaMariade_M.pdf: 1499249 bytes, checksum: 6a6d75c1ebef60cd31c4d9b2d7639186 (MD5) Previous issue date: 2008 / Resumo: A aplicação do laser de dióxido de carbono (CO2) à estrutura do esmalte modifica a composição química e/ou morfológica dessa superfície e inibe o desenvolvimento e a progressão de lesões cariosas. Porém, não foram realizadas pesquisas que tenham verificado se a irradiação do esmalte dental ao redor de braquetes ortodônticos com esse laser é efetiva em reduzir a desmineralização nessa região numa situação de alto desafio cariogênico. Assim, esta dissertação objetivou verificar, in vitro, se a irradiação do esmalte dental com laser de CO2 (?=10.6 µm e 10.0 J/cm2), associada ou não a liberação de fluoreto pelo material de colagem, seria capaz de reduzir a perda mineral do esmalte, ao redor de braquetes ortodônticos, quando submetido a uma situação de alto desafio cariogênico. Nesse estudo, 24 blocos de esmalte bovino foram divididos em 4 grupos, em triplicata: 1 ¿ resina composta não liberadora de fluoreto Transbond (T); 2 ¿ cimento de ionômero de vidro modificado por resina Fuji (F); 3 ¿ laser de CO2 + resina composta não liberadora de fluoreto (TL); 4 ¿ laser de CO2 + cimento de ionômero de vidro modificado por resina (FL). Um grupo contendo blocos de esmalte foi incluído apenas para análise de microdureza. Após a colagem dos braquetes, os espécimes foram suspensos em água destilada deionizada esterilizada e esterilizados com radiação gama. A seguir, foram transferidos para o meio de cultura esterilizado de caldo de cérebro-coração (BHI) contendo sacarose a 5% e os 4 grupos experimentais foram inoculados com uma cultura overnight de Streptococcus mutans. Diariamente, o meio BHI foi trocado e analisado quanto à contaminação microbiológica. Após 6 dias de incubação (37ºC - 10% CO2), o biofilme foi coletado e submetido as análises microbiológica (UFC/mg) e bioquímica. Além disso, microdureza do esmalte seccionado longitudinalmente foi determinada. Os dados foram analisados pelos testes ANOVA e Tukey, com alfa a 5%. As concentrações de polissacarídeo insolúvel em água (µg/mg) no biofilme foram: T ¿ 213,206(±421,746)a, F ¿ 111,208(±43,501)a, TL ¿ 124,626(±37,488)a e FL ¿ 138,83(±118,893)a. As concentrações de cálcio (µg/mg) foram: T ¿ 340,5(±27,01)a, F ¿ 329,5(±143,97)a, TL ¿ 412,3(±228,80)a e FL ¿ 411,8(±252,59)a. As concentrações de fluoreto (µg/mg) no biofilme foram: T ¿ 0,001(±0,005) a, F ¿ 0,010(±0,021) a, TL ¿ 0,0009(±0,002)a e FL ¿ 0,002(±0,007)a. As concentrações de fósforo (µg/mg) foram: T ¿ 0,162(±0,134)a, F ¿ 0,149(±0,066)a, TL ¿ 0,170(±0,104)a a e FL ¿ 0,148(±0,029)a. Os resultados (expressos 107 UFC/mg) obtidos da análise microbiológica foram: T ¿ 2,54(±2,58)a, F ¿ ,90(±3,08)a, TL ¿ 2,59(±3,13)a e FL ¿ 2,30(±4,04)a. A média numérica da microdureza knoop (kg/mm2) variou de 195,5(±87,3)c, 209,8(±75,0)bc, 218,2(±113,6)ab e 229,1(±82,7)a para os grupos T, F, TL e FL, respectivamente. Em conclusão, esse estudo demonstrou que o uso do laser de CO2 (?=10.6 µm e 10.0 J/cm2) sozinho ou combinado com o material de colagem liberador de fluoreto foi capaz de reduzir a perda mineral do esmalte ao redor de braquetes ortodônticos, quando submetidos a uma situação de alto desafio cariogênico com biofilme de Streptococcus mutans. / Abstract: The application of carbon dioxide laser (CO2) on dental enamel structure modifies the chemical and/or morphologic composition of this surface and inhibits the development and progression of caries lesion. However, no research verified the if the irradiation of dental enamel around orthodontic brackets was able to reduce the enamel mineral loss in this region in a high cariogenic challenge. Thus, this dissertation aimed to verify in vitro, if the irradiation of the dental enamel with a laser of CO2 (? =10.6 µm and 10.0 J/cm2), associated or not with fluoride released from a bonding material, will be able to reduce the enamel mineral loss around orthodontic brackets, when submitted to a high cariogenic challenge situation. In this study, twenty four enamel slabs were divided into 4 groups in triplicate: 1. nonfluoride-releasing composite resin Transbond (T); 2. resinmodified glass ionomer cement Fuji (F); 3. CO2 laser + nonfluoride-releasing composite resin (TL); 4. CO2 laser + resin-modified glass ionomer cement (FL). One group with 6 specimens of sound enamel were used to determine the sound enamel microhardness. After brackets bonding, the specimens were immersed in sterile deionized distilled water and sterilized with gamma radiation. Following, the specimens were transferred to a sterile brain-heart infusion broth (BHI) with a 5% sucrose solution and the 4 experimental groups were inoculated with an overnight culture of Streptococcus mutans. The BHI medium was daily changed and analyzed to check for microbiological contamination. After 6 days of incubation (37ºC - 10% CO2), the biofilm was collected and submitted to microbiological (CFU/mg) and biochemical analyses. Additionally, microhardness assay of the enamel longitudinally sectioned was determine. The data were statistically analyzed by the ANOVA and Tukey¿ tests, with an alpha of 0.05. The concentrations of water-insoluvel polysaccharide (µg/mg) in biofilm were: T ¿ 213.206(±421.746)a, F ¿ 111.208(±43.501)a, TL ¿ 124.626(±37.488)a e FL ¿ 138.83(±118.893)a. The concentrations of calcium (µg/mg) were: T ¿ 340.5(±27.01)a, F ¿ 329.5(±143.97) a, TL ¿ 412.3(±228.80)a e FL ¿ 411.8(±252.59) a. The concentrations of fluoride (µg/mg) in biofilm were: T ¿ 0.001(±0.005) a, F ¿ 0.010(±0.021)a, TL ¿ 0.0009(±0.002)a e FL ¿ 0.002(±0.007)a. The concentrations of phosphorus (µg/mg) were: T ¿ 0.162(±0.134)a, F ¿ 0.149(±0.066)a, TL ¿ 0.170(±0.104)a e FL ¿ 0.148(±0.029)a. The results (expressed 107 CFU/mg) obtained of microbiological analysis were: T ¿ 2.54(±2.58)a, F ¿ 2.90(±3.08)a, TL ¿ 2.59(±3.13)a e FL ¿ 2.30(±4.04)a. The mean knoop microhardness number (kg/mm2) varied from 195.5(±87.3)c,209.8(±75.0)bc, 218.2(±113.6)ab and 229.1(±82.7)a for T, F, TL and FL respectively. In conclusion, the present study demonstrated that the use CO2 laser (?=10.6 µm and 10.0 J/cm2) alone or combined with the release of fluoride by bonding material was capable of reducing the enamel mineral loss around the orthodontic brackets, when submitted to a high microbiological cariogenic challenge with a Streptococcus mutans biofilm. / Mestrado / Odontopediatria / Mestre em Odontologia
93

Avaliação da liberação de íon fluoreto de cimentos ionoméricos antes e após a recarga e com proteção da superfície

Antunes, Débora Pinto 01 January 2012 (has links)
Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-05-17T14:10:56Z No. of bitstreams: 1 deborapintoantunes.pdf: 1198844 bytes, checksum: d0dff20dab0cbefb8d4929858b0c3302 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-17T16:26:16Z (GMT) No. of bitstreams: 1 deborapintoantunes.pdf: 1198844 bytes, checksum: d0dff20dab0cbefb8d4929858b0c3302 (MD5) / Made available in DSpace on 2017-05-17T16:26:16Z (GMT). No. of bitstreams: 1 deborapintoantunes.pdf: 1198844 bytes, checksum: d0dff20dab0cbefb8d4929858b0c3302 (MD5) Previous issue date: 2012-01-01 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Avaliou-se a liberação de íon fluoreto de 2 cimentos de ionômero de vidro (CIV) anidro e 2 CIVs modificados por resina composta antes e após recarga com fluoreto de sódio neutro a 2% por 4min. e a proteção da superfície do CIV Maxxion R com um adesivo odontológico, um verniz cavitário e um esmalte incolor para unhas. Com uma matriz de aço inox com 2mm x 6mm, confeccionou-se 5 corpos de prova de cada material, os quais foram imersos em 5mL de água deionizada, trocada a cada 24h. Foram realizadas leituras em um potenciômetro calibrado acoplado a um eletrodo sensível a íons fluoreto nos dias 1, 2, 9 e 17 na 1ª e 2ª etapas, e as amostras foram tamponadas com solução TISAB III. Na 2ª etapa, as amostras foram submetidas à recarga e em seguida lavadas, secas e novamente imersas em 5mL de água deionizada. Na 3ª etapa foi realizada a proteção da superfície dos CIVs e feitas leituras nos 5min., 24h, 48h e 72h. Os dados foram submetidos aos testes estatísticos Post Hoc de Tukey e t Student (p<0,05). Concluiu-se que os CIVs anidros tiveram maior efetividade na liberação de íon fluoreto em comparação com os CIVs modificados por resina composta e o Maxxion R apresentou um comportamento homogêneo e estatisticamente significante nas duas etapas. Os CIVs possuem a capacidade de recarregar, especialmente os anidros. Todos os materiais protetores testados foram eficazes, e o esmalte incolor para unhas apresentou o melhor comportamento. / Was evaluated the fluoride ion release of 2 glass ionomer cements (GIC) and anhydrous 2 resin-modified GICs made before and after charge neutral sodium fluoride to 2% for 4 minutes. and protecting the surface of the IVC Maxxion R with a dental adhesive, a cavity varnish and a colorless nail polish. With an array of stainless steel with 6mm x 2mm, it was made five specimens of each material, which were immersed in 5 mL of deionized water, changed every 24 hours. Readings were taken in a calibrated potentiometer coupled to an electrode sensitive to fluoride ions on days 1, 2, 9 and 17 in the 1st and 2nd stages, and the samples were buffered with TISAB III solution. In Step 2, the samples were submitted to recharge and then washed, dried and again immersed in 5 mL of deionized water. In Step 3 was done to protect the surface of GICs and readings made in 5min., 24h, 48h and 72h. The data were subjected to statistical tests post hoc Tukey et Student (p <0.05). It was concluded that the GICs were more effective in anhydrous fluoride ion release compared to composite resin modified GICs and Maxxion R had a homogeneous behavior and statistically significant in two steps. The GICs have the ability to recharge, especially anhydrous. All protective materials tested were effective, and nail incolor enamel showed the best behavior.
94

Avaliação in vitro da resistencia ao cisalhamento de braquetes metalicos com e sem composito incorporado a base e cimentos de ionomero de vidro com variação da superficie de esmalte

Ramalli, Edvaldo Luiz 02 April 2005 (has links)
Orientador: Lourenço Correr Sobrinho / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-04T03:57:14Z (GMT). No. of bitstreams: 1 Ramalli_EdvaldoLuiz_D.pdf: 836688 bytes, checksum: 22c18067abe55c01f713fc62bbe6b0a6 (MD5) Previous issue date: 2005 / Resumo: O propósito deste estudo foi avaliar a resistência ao cisalhamento de braquetes metálicos (Victory Series, 3M Unitek, Monrovia, USA) com e sem compósito incorporado à base (APC II e APC Plus) e com os cimentos de ionômero de vidro modificados por resina (Fuji Ortho LC e Fuji Ortho Band), em diferentes condições de superfície de esmalte bovino. Após a remoção dos braquetes foi analisado o índice de remanescente do adesivo (IRA). Duzentos e quarenta incisivos inferiores permanentes bovinos foram incluídos centralizados em tubos de P.V.C. com resina acrílica ativada quimicamente com a face vestibular perpendicular à base do troquel. Na face vestibular dos dentes foram realizadas profilaxia com pedra-pomes e água por dez segundos, lavagem, secagem e os dentes divididos em dezesseis grupos (n=15): Grupo 1 ¿ condicionamento do esmalte com ácido fosfórico à 37%, lavagem e secagem +Transbond XT primer + APC II; Grupo 2 ¿ condicionamento do esmalte com ácido fosfórico à 37%, lavagem e secagem + esmalte umedecido com água destilada + Transbond XT primer + braquetes APC II; Grupo 3 ¿ esmalte seco + Transbond Plus Self-Etching Primer + braquetes APC II; Grupo 4 ¿ esmalte umedecido com água destilada + Transbond Plus Self-Etching Primer + braquetes APC II; Grupos 5 a 8 ¿ tratamento de superfície semelhante aos grupos 1 a 4, porém a colagem dos braquetes realizada com APC Plus; Grupos 9 a 12 - tratamento de superfície semelhante aos grupos 1 a 4, porém braquetes fixados com cimento de ionômero de vidro Fuji Ortho LC; Grupos 13 a 16; tratamento de superfície semelhante aos grupos 1 a 4, porém fixados com cimento de ionômero de vidro Fuji Ortho Band. Após a fixação, os corpos-de-prova foram armazenados em água destilada a 37oC por 24 horas, seguidos de 500 ciclos térmicos de 5oC e 55oC, com duração de 30 segundos em cada banho. Em seguida, os corpos-de-prova foram submetidos ao ensaio de resistência ao cisalhamento em máquina Instron (Modelo 4411) com velocidade de 0,5 mm/min. Os dados foram submetidos à análise de variância e ao teste de Tukey (5%) e mostraram que independente do tratamento superficial do dente, o APC Plus mostrou valores de resistência ao cisalhamento estatisticamente superiores em relação ao Fuji Ortho LC, APC II e Fuji Ortho Band que apresentou o menor valor. Independente do material de colagem, nenhuma diferença estatística foi observada entre os quatro tratamentos de superfície. Com relação ao IRA, para os materiais APC II, APC Plus e Fuji Ortho LC, não houve influência dos diferentes tratamentos superficiais. No entanto, para o material Fuji Ortho Band, o tratamento com o TPSEP em ambiente seco mostrou maior remanescente do adesivo na estrutura dentária, e, para os tratamentos superficial úmido e seco, os materiais APC Plus e Fuji Ortho LC mostraram os mais altos índices de remanescente do adesivo. Com o TPSEP na condição de ambiente seco, não houve diferença estatística significante entre os materiais. Já com o TPSEP na condição úmido, os materiais APC Plus e Fuji Ortho LC mostraram os mais altos índices de IRA / Abstract: The aim of this study was to evaluate the shear bond strength from orthodontic brackets (Victory Series) bonded with composites (APC II and APC Plus) and resin-modified glass ionomer cements (Fuji Ortho LC and Fuji Ortho Band) applied on bovine enamel surface under different enamel conditions (either dry or moisten with distilled water). The adhesive remnant index (ARI) was evaluated after the bracket removal. Two hundred and forty mandibular incisors were included into PVC tubes with chemically activated acrylic resin leaving the vestibular face of perpendicularly to the botton plane of the tube. The vestibular face of all the teeth were cleared with nonfluoridated pumice and water for 10 seconds, washed 10 seconds, dried for the same time and divided into 16 groups (n = 15): Group 1 ¿ enamel etched with 37% phosphoric acid, washed and dried + Transbond XT primer + APC II; Group 2 ¿ enamel etched with 37% phosphoric acid, washed and dried + enamel moistened with distilled water + Transbond XT primer + APC II; Group 3 ¿ dried enamel + Transbond Plus Self Etching Primer + APC II; Group 4 ¿ enamel moistened with distilled water + Transbond Plus Self Etching Primer + APC II; Groups 5 to 8 ¿ enamel surface treatment similar to those from Groups 1 to 4, but brackets bonded with APC Plus; Groups 9 to 12 ¿ enamel surface treatment similar to those from Groups 1 to 4, but brackets bonded with glass ionomer cement (Fuji Ortho LC); Groups 13 to 16 ¿ enamel surface treatment similar to those from Groups 1 to 4, but brackets bonded with glass ionomer cement (Fuji Ortho Band). After the bonding procedures, all samples were stored in distilled water at 37oC for 24 hours, followed by 500 thermocycle between 5 and 55oC, during 30 seconds. The shear bond strength was performed using an Instron universal testing machine (model 4411) at a crosshead speed of 0.5 mm/min. The values were submitted to ANOVA and Tukey¿s test (5%) and showed that, regardless of the enamel surface treatment, the shear bond strength values concerning the APC Plus were statistically greater than those obtained by using Fuji Ortho LC, APC II or Fuji Ortho Band material. Regardless of the bonding material, it was observed no statistical difference between the four enamel surface treatments. In relation to the adhesive remnant index, no influence was observed for the different treatments using APC II, APC Plus or Fuji Ortho LC material. In relation to the Fuji Ortho Band material, however, the conventional treatment using Transbond Plus Self-Etching Primer (TPSEP) showed a better ARI score for the dental structure than the other treatments. In addition, the conventional treatments using APC Plus and Fuji Ortho LC materials for moistened enamel surface showed the highest ARI scores. Regardless of the material used, the Transbond Plus Self- Etching Primer conventionally used showed no difference. On the other hand, the Transbond Plus Self-Etching Primer used under moistened condition showed the highest ARI scores for both APC Plus and Fuji Ortho LC materials / Doutorado / Ortodontia / Doutor em Ortodontia
95

Longevity of Crown Margin Repairs Using Glass Ionomer: A Retrospective Study

Watson, Justin I. January 2020 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Objectives: Repair of crown margins may extend the functional life of existing crowns. However, the longevity of such treatment is unknown. This study determined the survival time of crown margin repairs (CMR) with glass-ionomer (GI) and resin-modified glass-ionomer cements. Methods: We queried axiUm (Exan Group, Coquitlam, BC, Canada) database for permanent teeth that underwent CMR in the Graduate Operative Dentistry Clinic, Indiana University School of Dentistry (IUSD), Indianapolis, Ind., USA, from January 1, 2006 through January 1, 2018. Since there is no CDT code for the CMR procedure, CDT codes for resin-composite and GI restorations (D23XX) were queried; these patients also had treatment notes that indicated CMR. The final data set included patient ID, birth date, gender, dates of treatments, CDT codes, tooth type, tooth surface and existing findings. Two examiners developed guidelines for record review and manually reviewed the clinical notes of patient records to confirm CMR. Only records that were confirmed with the presence of CMR were retained in the final dataset for survival analysis. Survival time was calculated by Kaplan-Meier statistics and a Cox Proportional Hazards model was performed to assess the influence of selected variables (p < 0.05). Results: 214 teeth (115 patients) with CMR were evaluated. Patient average age was 69.4  11.7 years old. Posterior teeth accounted for 78.5 percent (n = 168) of teeth treated. CMRs using GI had a projected 5-year survival rate of 62.9 percent (K-M Analysis) and an 8.9 percent annual failure rate. Cox Proportional Hazards Regression analysis revealed that none of the factors examined (age, gender, tooth type) affected time to failure. Conclusion: CMRs may extend the longevity of crowns with defective margins. Larger EHR studies or case control studies are needed to investigate other variables, such as the caries risk status or the severity of defects that may affect the survival rate of CMRs.
96

Evaluation of water sorption and solubility behavior of nine different polymeric luting materials

Alsheikh, Rasha N. January 2009 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / The cementation procedure is the key to long-term success of fixed restorations. The prognosis of prosthetic restoration is largely impacted by the maintenance of the luting cement and the adhesive bond. When exposed to water or saliva, most restorative materials undergo hydrolytic degradation. The purpose of this study is to evaluate the water solubility and water sorption characteristics of newly introduced acidic polymeric luting agents over a 180-day water-storage period. Nine different luting agents were tested. Fifty-two disc specimens of each material were fabricated using a mold with an internal dimension of 15[plus-minus]0.1 mm in diameter and 1.0 [plus-minus]0.1 mm deep. A constant weight, W0 [subscript zero], was reached after desiccating the specimens. Then, 13 specimens were assigned randomly to one of the four testing periods in the water for seven, 30, 90 and 180 days. After each period, the specimens were removed from the water and weighed to get W1 [subscript one]. A second period of desiccating the samples provided a constant weight W2 [subscript two]. The water sorption and solubility were determined by the following equations: WSP [subscript SP](%) = (W1 [subscript one] W2 [subscript two] ) X 100/ W0 [subscript zero] ,WSL [subscript SL](%) = (W0 [subscript zero] W2 [subscript two) X 100/ W0 [subscript zero]. The resin-modified glass-ionomers showed the highest water sorption/solubility results. The resin luting agents had the lowest sorption/solubility results. The self-adhesives showed a wide range of solubility/sorption; in general, they showed lower results compared with the resin-modified glass-ionomers. All the materials reached some sort of equilibrium after 90-days. Based on the results of our study, we conclude that self-adhesive luting materials were not all alike. Rely X Unicem was the most comparable to the resin luting materials. The resin luting materials had the lowest solubility and sorption. Resin-modified glass-ionomers showed the highest sorption/solubility results.
97

Microleakage in new resin-modified glass ionomer cements using new no-rinse conditioners : an in-vitro study

Patel, Ashish G. January 2012 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Since their introduction in 1970, glass ionomer cements have been used in a wide variety of clinical situations in dentistry. The main advantages of glass ionomer cements are chemical bonding, fluoride release and uptake, excellent seal against microleakage, and biocompatibility. The main objective of this study was to compare the microleakage of two new paste-paste glass ionomer systems to their traditional RMGIC counterparts when conditioning the dentin with newly developed no-rinse conditioners or polyacrylic acid. Materials and methods: Standardized cavity preparations were made, centered on the cementoenamel junction of the buccal surface, on 96 extracted human molars divided in 8 groups (n = 12). G1 Ketac Nano with Ketac Nano Primer, G2 Ketac Nano with Ketac Conditioner, G3 Photac Fil with Ketac Nano Primer, G4 Photac Fil with Ketac Cavity Conditioner, G5 Fuji Filling LC with GC Self Conditioner, G6 Fuji Filling LC with GC Cavity Conditioner, G7 Fuji II LC with GC Self Conditioner, G8 Fuji II LC with GC Cavity Conditioner. The cavities were treated with either a no-rinse or polyacrylic acid conditioner and restored with a paste-paste RMGIC or traditional RMGIC from the same manufacturer (n =12). The teeth were then sealed to within 2 mm of the restoration margins and thermocycled. The teeth were immersed in 2.0-percent methylene blue and stored at room temperature for 24 hours. Then, the teeth were be embedded in resin and sectioned longitudinally in a buccolingual direction making 1 section (1 mm thick) per tooth. The occlusal and gingival restoration margins of each specimen were examined with a stereomicroscope at X10 magnification to determine the degree of microleakage. Results: Mixed-model ANOVA was used to test the fixed effect of the eight groups and cervical vs. occlusal location within each tooth sample on microleakage, with sample as the random effect. Both main effects and the interaction are significant, p < 0001 for both group and location effects, and p = 0.0013 for the interaction of group and location. The cervical interface showed more microleakage in all groups except group 8 where microleakage was the same as at the occlusal margin. No significant difference was observed among groups for microleakage at the occlusal interface. There was significant difference among groups at the cervical interface with Fuji II LC using GC Cavity Conditioner performing best. For the occlusal interface Group 4 performed the best and Group 2 performed the worst, although the difference was not significant among the groups. For the cervical interface, Group 8 performed the best followed by Group 3, Group 4 and Group 6, although these four groups were not significantly different. For the cervical interface, group 2 performed the worst followed by group 1. Based on these results we can conclude that, overall, traditional RMGIC with polyacrylic acid conditioning performed better than the new paste-paste RMGIC systems utilizing the no-rinse conditioners.
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Avaliação da microdureza Knoop e do grau de conversão de dois cimentos de ionômero de vidro modificados por resina em função do tipo de polimerização e do tempo / Evaluation of the Knoop microhardness and the degree of conversion of two resin-modified glass ionomer in function of the type of polymerization and the time

Martins, Leandro de Moura 21 May 2007 (has links)
Os ionômeros de vidro vêm sendo utilizados largamente na odontologia com diversas funções. Suas formulações sofreram alterações durante os anos, como a incorporação de componentes resinosos, para a melhoria de suas propriedades físicas e aumento do tempo de trabalho. Com isso, o estudo teve como objetivo avaliar o grau de conversão e a microdureza Knoop dos cimentos de ionômero de vidro modificados por resina (Rely X Luting e Vitremer, ambos da 3M ESPE) de acordo a forma de polimerização (química ou fotopolimerável por lâmpada halógena Ultralux EL ? Gnatus e LED LEC 1000 ? MMOptics) e o tempo de armazenagem. Três espécimes de cada material, autopolimerizável e fotopolimerizável, e tipo de fotopolimerização (por luz halógena e LED) foram confeccionados para cada tempo experimental de 6 horas, 1, 2, 3, 5, 7 ,11 e 14 dias (n=72). Os espécimes foram armazenados em ambiente escuro a 37°C durante esses períodos. Os 72 espécimes foram analisados pela espectroscopia FT-IR para a medição do grau de conversão (GC). Três espécimes de cada material e tipo de polimerização (n=9) foram confeccionados para a medição da microdureza, com um penetrador diamantado piramidal, tipo Knoop, carga estática de 50 gramas por 30 segundos. Os resultados encontrados demonstraram que o material fotopolimerizado com LED apresentou os maiores valores do grau de conversão e da microdureza. O grau de conversão aumentou com o tempo de armazenagem enquanto a microdureza obteve os maiores resultados entre 24-48 horas. Os resultados permitiram concluir que para os cimentos de ionômero de vidro modificados por resina, Vitremer e Rely X Luting, o material fotopolimerizável onde se utilizou o LED apresentou os melhores resultados e que a microdureza Knoop foi ineficaz para predizer o grau de conversão. / Glass ionomer cement have been widely used for many functions. Over the years, some alterations have been made to improve some physico-mechanical properties and to prolong working time. The purpose of this study was to evaluate the relation of the degree of conversion (DC) and Knoop microhardness of resin modified glass ionomer cements (Rely X Luting and Vitremer - 3M ESPE) with polymerization type (chemical curing and light curing reactions, using halogen light or LED) and time of storage. Three specimens of each material, self-cured and light-cured, and light-curing type (halogen light or LED) were prepared for each period of time (n=72). Specimens were stored in dark and dry conditions, at 37oC, during 6 hours, 1, 2, 3, 5, 7, 11 and 14 days. All the specimens were analyzed by FT-IR spectroscopy to measure the DC. Three specimens of each material and polimeryzation type (n=9) were prepared for the microhardness determination, equipped with a Knoop indenter, 50g load for 30 seconds. Results showed that higher values of DC and Knoop microhardness were found on the LED light-cured material. DC values increased with storage time while the Knoop microhardness achieved its higher values between 24-48 hours. Results showed that the LED light-curing unit used to polymerize the resin modified glass ionomer cement Vitremer achieved better values of DC, between light and self-cured materials, and that the Knoop microhardness could not predict the DC.
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Avaliação da influência do ultra-som em cimentos de ionômero de vidro na adesão à dentina e nas características dentinárias / Evaluation of ultrasound influence on glass ionomer cement (GIC) regarding its adhesion to dentin and the clinical dentin characteristics

Bresciani, Eduardo 23 June 2007 (has links)
Avaliou-se diferentes formas de aplicação do ultra-som (US) sobre a microtração de CIVs (Ketac Molar Aplicap, Ketac Molar Easymix e Fui IX GP) à dentina; e o potencial clínico de restaurações de CIV (Ketac Molar) com US remineralizarem a dentina e seu efeito sobre a flora bacteriana por meio PCR em tempo real, após período de três meses. Na parte laboratorial, foram selecionados 45 terceiros molares extraídos e confeccionadas cavidades para acomodar material, que aleatoriamente recebeu US diretamente (US-D), ou indiretamente (US-I) ou ainda não recebeu (S-US). Os espécimes foram reservados por 1 semana, submetidos ao teste de microtração e os dados analisados por ANOVA 2-critérios. Na parte clínica, 32 pacientes (idade média 13,8) receberam 90 restaurações com CIV, CIV com ultra-som e resina composta, aleatoriamente. A dentina afetada foi avaliada de acordo com a cor, umidade e dureza e uma amostra foi colhida para quantificação de bactérias totais e Lactobacilos. Após três meses, as restaurações foram removidas e nova caracterização clínica e amostragem realizadas. Os dados obtidos foram submetidos aos testes de Friedman e Mann-Witney para os critérios clínicos e ao teste de procedimento de medidas repetidas SAS, para o número de bactérias (p<0,05). Os resultados mostraram que o ultra-som influenciou na adesão dos CIVs, sendo US-D<S-US<US-I. Após três meses de estudo clínico, a dentina apresentouse dura e seca com maior freqüência. A coloração não apresentou mudanças significantes. O número de bactérias totais não foi influenciado pelo tipo de tratamento restaurador. Mais da metade das amostras não mostrou níveis detectáveis de Lactobacilos e nenhuma atividade foi observada. Concluiu-se que o método de aplicação indireta do US deve ser o escolhido. O tipo de tratamento restaurador não influenciou na redução de bactérias residuais, nem na atividade metabólica, embora a dentina apresentasse características clínicas compatíveis com paralisação do processo carioso. / The microtensile bond strength of GICs (Ketac Molar Aplicap, Ketac Molar Easymix and Fuji IX GP), receiving different patterns of ultrasound (US), was evaluated. The clinical potential of GIC (Ketac Molar) restorations with US, in remineralizing dentin and their effects on the microflora were also evaluated. Forty-five extracted third molars were selected for the laboratorial study, and cavities were performed for the GIC filling, which received direct US (D-US), indirect US (I-US) or no US excitation (N-US). After one week, the microtensile test was performed. The obtained data was analyzed using 2-way ANOVA test (P<0.05). Thirty-two patients (mean age of 13.8) were selected for the clinical study and 90 restorations were randomly performed with GIC, GIC plus US or composite resin (CR). The affected dentin was assessed by color, humidity and hardness and a dentin sample was obtained for total bacteria and Lactobacilli quantification, using real time PCR. After 3 months, the restorations were removed and new dentin characterization and sampling performed. Clinical data were analyzed by Friedman and Mann-Whitney tests. Bacterial counts were analyzed by Repeated Measurements Procedure (P<0.05 for all tests). Results showed statistical significant influences of the US on the GIC adhesion to dentin, being D-US<N-US<IUS. After three months of clinical trial, the dentin was scored more frequently as hard and dry. Color was not statistical different in both evaluation periods. The number of total bacteria was not influenced by the type of treatment. Lactobacilli were detected in less than 50% of the samples and presenting no metabolic activity. It was conclude that I-US should be the choice protocol to achieve better adhesion. Although the treated lesions presented clinical characteristics of arrested caries, the type of restoration did not influence the residual bacteria, neither their metabolic activity.
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Avaliação da perda mineral decorrente do processo cariogênico e erosivo ao redor de restaurações de cimento de ionômero de vidro / Evaluation of mineral loss after cariogenic and erosive challenges on adjacent enamel glass ionomer cements restorations

Salas, César Felipe Chuquillanqui 01 September 2010 (has links)
O cimento de ionômero de vidro tem mais de 40 anos de uso clínico, com muitas boas qualidades e propriedades de material para forramento e restauração. Como o principal motivo de troca de restaurações é a lesão de cárie secundária, a sua capacidade de indução de remineralização e inibição de desmineralização mostram uma qualidade desejável desse material. Além disso, não se sabe até que ponto o flúor liberado pelos cimentos de ionômeros de vidro é capaz de inibir o processo erosivo. Portanto, o objetivo deste trabalho foi avaliar a capacidade de inibição dos desafios cariogênicos em dentes restaurados com diferentes tipos de materiais ionoméricos restauradores, bem como avaliar a inibição dos mesmos materiais frente a um desafio erosivo. Foram confeccionados 120 fragmentos de dentes bovinos, que foram divididos aleatoriamente em seis grupos, para serem restaurados com diferentes tipos de cimentos de ionômero de vidro (CIV): CIV de alta viscosidade (Fuji IX), CIV modificado por resina (Vitremer), CIV modificado por resina com nanopartículas (N100), CIV modificado por resina encapsulado (Riva Light Cure), CIV de alta viscosidade encapsulado (Riva Self Cure) e um grupo controle com resina composta (Filtek Z350). Após a restauração de tamanho padronizado, seguindo as indicações do fabricante, os espécimes foram submetidos à desafio cariogênico (ciclagem de pH) e erosivo (ácido cítrico). Microdureza superficial do tipo Knoop das amostras foi avaliada inicialmente. Após 24 horas de desafio erosivo, e 5 dias de ciclagem de pH (desafio cariogênico), uma nova avaliação de microdureza foi realizada para avaliar a perda mineral ao redor das restaurações. Na avaliação estatística, utilizou-se o teste de normalidade de Anderson-Darling e teste de homogeneidade de Levene. Para as comparações, foi realizada análise de variância e teste de contraste de Student-Newman Keuls, com nível de significância de 5%. O desafio erosivo reduziu significantemente a dureza superficial, mas nenhuma diferença significante foi observada independentemente do material restaurador (p>0,05). Para análises do esmalte ao redor, diferenças significantes foram observadas com relação aos diferentes materiais (p<0,001) e distâncias das restaurações (p=0,023). Espécimes restauradas com resina apresentaram maior perda mineral e amostras restauradas com CIV convencional de alta viscosidade e CIV encapsulado modificado por resina apresentaram os menores valores de perda mineral. Em conclusão, os CIVs exercem efeito protetor no esmalte apenas contra desafio cariogênico. / The glass ionomer cements (GIC) has more than 40 years been used in clinical practice, with good qualities and properties as dental material of liner and restoration. Since the main reason of restoration replace is secondary caries lesion, the ability of the GIC in inducing remineralization and inhibiting demineralization are important characteristics of this type of material. Furthermore, it is still unclear if the fluoride released by the GIC is able to inhibit the erosive process. Therefore, the aim of this study was to evaluate the ability of inhibition of cariogenic challenge in teeth restored with different types of GIC, as well as to evaluate the inhibition of the same materials concerning erosive challenge. One hundred and twenty samples of bovine teeth were prepared and randomly divided in 6 groups, in order to be submitted to restorative procedures with different types of GIC: High viscous GIC (Fuji IX), resin-modified GIC (Vitremer), resin-modified GIC with nanoparticles (N100), encapsulated resinmodified GIC (Riva Light Cure),encapsulated high viscous GIC (Riva Self Cure) and a control group with resin (Filtek Z350). Knoop microhardness evaluations were initially performed. After performing restorations with standardized dimensions and according to the manufacturers instructions, the samples were submitted to cariogenic challenge (pH cycling) and erosive challenge (citric acid). After 24 h of erosive challenge, and 5 days of pH cycling, new microhardness assessments were performed to evaluate mineral loss around of restorations. For statistical analysis, it was used Anderson-Darling test to test the normality and Levene test to check the homogeneity of the data. To compare the different groups, it was used Analysis of variance and Student-Newman-Keuls post-hoc test, considering the level of significance of 5 %. Erosive challenge significantly reduced enamel surface hardness, but no significant difference was observed irrespectively restorative materials (p>0.05). For enamel analyses, significant differences were observed with respect to the different materials (p<0.001) and distances (p=0.023).Specimens restored with the composite resin presented higher mineral loss and specimens restored with the conventional high viscous GIC and the encapsulated resin-modified GIC presented the lowest values for mineral loss. In conclusion, the GICs exert protective effect only for cariogenic challenge.

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