Avaliação da adaptação marginal e resistencia compressiva de restaurações esteticas tipo onlay e da dureza knoop de um cimento resinoso dual
Andreia Bolzan de Paula
DISSERTAÇÃO
Português
(Broch.)
T/UNICAMP P281a
[Evaluation of marginal fit and compression strenght of onlay esthetic restorations and Knoop hardness of a dual-cured resin cements]
Piracicaba, SP : [s.n.], 2007.
76f. : il.
Orientador: Regina Maria Puppin-Rontani
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba
Resumo: O avanço da Odontologia Estética tem sido impulsionado pela introdução de novos compósitos resinosos e técnicas restauradoras. Para amenizar as falhas associadas à contração de polimerização, a técnica indireta tem se tornado uma alternativa na restauração de dentes com preparos extensos....
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Resumo: O avanço da Odontologia Estética tem sido impulsionado pela introdução de novos compósitos resinosos e técnicas restauradoras. Para amenizar as falhas associadas à contração de polimerização, a técnica indireta tem se tornado uma alternativa na restauração de dentes com preparos extensos. Entretanto, a polimerização incompleta do agente cimentante pode ocasionar redução do desempenho físico e mecânico da restauração. Dessa forma, os objetivos desta dissertação foram: (1) avaliar o efeito da técnica restauradora e do tratamento termo/mecânico na adaptação marginal e resistência compressiva de restaurações estéticas tipo onlay fixadas com cimento resinoso e (2) a influência de diferentes espessuras de compósito resinoso e distâncias da ponta ativa do aparelho fotoativador na dureza Knoop do agente cimentante Rely-X ARC utilizado nas restaurações indiretas. No estudo 1, preparos tipo onlay foram realizados em 50 terceiros molares hígidos e restaurados com compósito resinoso Z-250. Os dentes foram separados em grupos de acordo com a técnica restauradora (direta/indireta) e a ciclagem termo/mecânica. Para a análise da adaptação marginal foi aplicada uma solução corante nas margens da restauração e as áreas coradas foram consideradas como presença de fendas marginais, as quais foram mensuradas através do software Image Tool 3.0. Todos os espécimes foram submetidos ao teste de resistência à compressão. No estudo 2 foi utilizado um incisivo bovino incluído em resina de poliestireno. A face vestibular foi planificada e sobre ela aplicada uma película de PVC e uma matriz de borracha, dentro da qual foi inserido o cimento resinoso Rely-X ARC e uma nova película de PVC. Discos de compósito resinoso, de espessuras diferentes, foram confeccionados e inseridos individualmente sobre este conjunto e fotoativados por 40 segundos, variando a distância da ponta ativa do fotoativador. Após armazenagem por 24h a 37oC, as amostras foram seccionadas longitudinalmente ao meio e polidas para mensuração da dureza Knoop em 3 profundidades do cimento. No estudo 1, não houve diferença estatisticamente significativa entre as técnicas restauradoras quanto à presença de fendas, entretanto, o tratamento termo/mecânico influenciou significativamente o aumento de fendas marginais. Na resistência à compressão não houve diferença estatística significativa entre as técnicas restauradoras empregadas e o tratamento termo/mecânico também não influenciou significativamente à resistência à compressão (RC). No estudo 2, a distância da ponta ativa do fotoativador assim como diferentes espessuras do disco de resina composta, resultou em valores de dureza Knoop estatisticamente distintos, nas profundidades. O aumento da espessura do disco de compósito resinoso ocasionou diminuição dos valores de dureza do cimento. Foi observado diminuição dos valores de dureza apenas quando foi utilizada a distância da ponta do fotoativador de 1mm. As regiões de base e centro apresentaram, respectivamente, os menores e maiores valores de dureza Knoop. Com base nos resultados obtidos pode-se concluir que as técnicas direta e indireta para restauração tipo onlay apresentaram similar resistência à fratura por compressão. A adaptação marginal foi influenciada pelo tratamento termo/mecânico; com o aumento da espessura do compósito restaurador e da distância do fotoativador, houve redução dos valores de dureza do cimento resinoso
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Abstract: Esthetic Dentistry has advanced increasingly with the introduction of new resin composites and restorative techniques. To reduce failures associated with polymerization contraction, indirect technique has become an alternative to restoration of teeth with extensive preparations. However,...
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Abstract: Esthetic Dentistry has advanced increasingly with the introduction of new resin composites and restorative techniques. To reduce failures associated with polymerization contraction, indirect technique has become an alternative to restoration of teeth with extensive preparations. However, the incomplete polymerization of luting agent can cause a decrease in the physical/mechanical performance of restorations. The objectives of this dissertation were to evaluate:
(1) the effect of restorative technique and thermo/mechanical cycling on themarginal adaptation and compressive strength of onlay esthetic restorations bonded with luting resin agent and (2) the influence of different thickness of resin composite discs and the distances of tip of curing unit on Knoop hardness of luting agent Rely-X ARC used in indirect restorations. In the study 1, onlay cavity preparations were performed in 50 sound third molars that were restored with resin composites Z-250. The teeth were divided in groups according to the restorative technique (direct/indirect) and the thermal/mechanical cycling. To analyze the marginal adaptation, a dye solution was applied on the restoration margins and the dyed areas were considered as marginal gaps and measured by means of Image Tool 3.0 software. All specimens were submitted to mechanical test of compressive strength. In the study 2, a bovine incisor was embedded in a polystyrene resin. The buccal surface was ground flatted and over it was applied a PVC pellicle and a rubber mold. The luting cement Rely-X ARC was inserted into the mold and a new PVC pellicle was applied. Resin composite discs, with different thickness, were performed and placed individually over this set (tooth/luting cement) and polymerized for 40 seconds, modifying the distance of tip of light curing. After storing at 37o C for 24 hours, specimens were longitudinally sectioned in two equal parts and polished to measure the Knoop hardness in three depth of cement. In the study 1, there was no statistically difference between the restorative techniques in relation to marginal gaps; however, thermal/mechanical cycling exerted significant influence on the increase of marginal gaps. About the compressive strength, any statistically difference was observed among the restorative techniques, independent of the thermal/mechanical cycling. In the study 2, the distance of tip of curing unit and distinct thickness of composite resin discs resulted in statistically different Knoop values when deepness was analyzed. The increase of resin disc thickness causes reduction on the hardness values of cement. Reductions on hardness values were observed only with 1mm tip curing unit distance. The base showed the lowest means while the center showed the highest. Based in the results obtained it could be concluded that direct and indirect techniques to onlay restoration had similar compressive strength. Marginal adaptation was influenced by thermal/mechanical cycling; increasing of resin composite thickness and distance of active tip of light curing unit, there was a reduction of hardness values of resin cement Ver menos
(1) the effect of restorative technique and thermo/mechanical cycling on themarginal adaptation and compressive strength of onlay esthetic restorations bonded with luting resin agent and (2) the influence of different thickness of resin composite discs and the distances of tip of curing unit on Knoop hardness of luting agent Rely-X ARC used in indirect restorations. In the study 1, onlay cavity preparations were performed in 50 sound third molars that were restored with resin composites Z-250. The teeth were divided in groups according to the restorative technique (direct/indirect) and the thermal/mechanical cycling. To analyze the marginal adaptation, a dye solution was applied on the restoration margins and the dyed areas were considered as marginal gaps and measured by means of Image Tool 3.0 software. All specimens were submitted to mechanical test of compressive strength. In the study 2, a bovine incisor was embedded in a polystyrene resin. The buccal surface was ground flatted and over it was applied a PVC pellicle and a rubber mold. The luting cement Rely-X ARC was inserted into the mold and a new PVC pellicle was applied. Resin composite discs, with different thickness, were performed and placed individually over this set (tooth/luting cement) and polymerized for 40 seconds, modifying the distance of tip of light curing. After storing at 37o C for 24 hours, specimens were longitudinally sectioned in two equal parts and polished to measure the Knoop hardness in three depth of cement. In the study 1, there was no statistically difference between the restorative techniques in relation to marginal gaps; however, thermal/mechanical cycling exerted significant influence on the increase of marginal gaps. About the compressive strength, any statistically difference was observed among the restorative techniques, independent of the thermal/mechanical cycling. In the study 2, the distance of tip of curing unit and distinct thickness of composite resin discs resulted in statistically different Knoop values when deepness was analyzed. The increase of resin disc thickness causes reduction on the hardness values of cement. Reductions on hardness values were observed only with 1mm tip curing unit distance. The base showed the lowest means while the center showed the highest. Based in the results obtained it could be concluded that direct and indirect techniques to onlay restoration had similar compressive strength. Marginal adaptation was influenced by thermal/mechanical cycling; increasing of resin composite thickness and distance of active tip of light curing unit, there was a reduction of hardness values of resin cement Ver menos
Puppin-Rontani, Regina Maria, 1959-
Orientador
Segalla, Jose Claudio Martins, 1955-
Avaliador
Correr Sobrinho, Lourenço, 1960-
Avaliador
Avaliação da adaptação marginal e resistencia compressiva de restaurações esteticas tipo onlay e da dureza knoop de um cimento resinoso dual
Andreia Bolzan de Paula
Avaliação da adaptação marginal e resistencia compressiva de restaurações esteticas tipo onlay e da dureza knoop de um cimento resinoso dual
Andreia Bolzan de Paula
Exemplares
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