Influência de técnicas e materiais de moldagem, tempos e materiais de vazamento na exatidão tridimensional de modelos
Carregando...
Data
2019-08-02
Autores
Messias, Aion Mangino
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Este estudo analisou a exatidão de modelos totais de gesso, obtidos a partir de diferentes técnicas e materiais de moldagem, tempos e materiais de vazamento, levando em consideração as mensurações de área, volume e angulação nos eixos X, Y e Z de pontos de referência específicos em modelo mestre (baseline), moldes e, por posteriormente, em modelos de gesso de cada condição experimental. Foi utilizado um modelo mestre com preparos nos dentes 14, 16, 21 e 25, com demarcações pontuais em suas superfícies oclusais, que funcionavam como pontos de referência. Realizaram-se três técnicas de moldagem: (T1) mistura simultânea, (T2) reembasamento – alívio com filme de PVC e (T3) moldagem digital (escâner intra-oral) – Cerec Conect Omnicam (Sirona). Para cada técnica de moldagem/tempo de vazamento foram obtidos 8 moldes totais, por único operador calibrado (ICC=0,99), com moldeira metálica de estoque e silicone de condensação (Speedex; Coltène/Whaledent Inc.) ou adição (Express XT; 3M ESPE). Os vazamentos foram realizados com gessos tipo IV convencional (GC Fuji Rock EP - GC America) e de expansão nula (Zero Stone - Dentona AG). Nos moldes com silicone de condensação o gesso foi vazado após 30 minutos, 3 ou 7 dias. Nos moldes em silicone de adição os modelos foram obtidos após 2 horas, 3, 7 ou 15 dias. Para a análise tridimensional, utilizou-se software para gerenciamento de imagens e análise das malhas tridimensionais (Rhinoceros - versão 5.3.2) obtidas com escâner óptico de bancada (R700 - 3ShapeA/S) a partir dos moldes e modelos de T1 e T2, bem como das imagens digitais adquiridas a partir de T3. Verificou-se os resultados quanto ao número amostral com poder estatisticamente significante, distribuição dos dados amostrais e homocedasticidade. Em seguida, métodos estatísticos foram empregados (Análise de Variância a três critérios e teste post-hoc de Tukey HSD) para avaliar a influência das variáveis independentes do estudo, com nível de significância de 5,0 %. De maneira geral, assim como para os moldes, a maioria absoluta das comparações dos resultados dos modelos não apresentaram resultados diferentes entre si. Conclui-se que não houve diferença entre os grupos experimentais e baseline, para a exatidão dos moldes e modelos obtidos, independentemente da técnica de moldagem, tempo e gesso de vazamento utilizados.
This study analyzed the accuracy of total gypsum casts obtained from different casting techniques and materials, casting times and materials, taking into account the measurements of area, volume and angulation in the X, Y and Z axes of reference points specific master model (baseline), in the impression and, later, in the gypsum casts of each experimental condition. A master model was used with teeth 14, 16, 21 and 25, with punctual demarcations on its occlusal surfaces, which functioned as reference points. Three impression techniques were performed: (T1) simultaneous mixing, (T2) relining-relief with PVC film and (T3) chairside digital impression - Cerec Conect Omnicam (Sirona). For each impression technique / casting time, 8 total impression were obtained by single calibrated operator (ICC = 0.99), with metal stock tray and condensation silicone (Speedex; Coltène / Whaledent Inc.) or addition (Express XT 3M ESPE). The gypsum casts pouring process were performed with type IV conventional gypsum (GC Fuji Rock EP - GC America) and zero expansion one (Zero Stone - Dentona AG). For impressions with condensation silicone the cast was poured after 30 minutes, 3 or 7 days. For the addition silicone impressions, the gypsum casts were obtained after 2 hours, 3, 7 or 15 days. For the three-dimensional analysis, a software was used to manage threedimensional images (Rhinoceros - version 5.3.2) allowing the investigation of virtual images (three-dimensional meshes) made with an optical laboratorial digitizer (R700 - 3Shape A/S) of the impressions and gypsum casts from T1 and T2, as well as, digital images acquired from T3. It were verified the results regarding the sample number with statistically significant power, distribution of the sample data and homoscedasticity. Afterwards, statistical methods were used (ANOVA 3-way and post hoc Tukey HSD) to evaluate the influence of the independent variables of the study, with significance level of 5.0%. Overall, as for the impressions results, the majority of the comparisons from the gypsum casts results did not present statistics differences between them. It is concluded that there is no difference between the experimental and baseline groups, for the precision of the impressions and gypsum casts obtained, regardless the impression technique, pouring time and type of gypsum stone used.
This study analyzed the accuracy of total gypsum casts obtained from different casting techniques and materials, casting times and materials, taking into account the measurements of area, volume and angulation in the X, Y and Z axes of reference points specific master model (baseline), in the impression and, later, in the gypsum casts of each experimental condition. A master model was used with teeth 14, 16, 21 and 25, with punctual demarcations on its occlusal surfaces, which functioned as reference points. Three impression techniques were performed: (T1) simultaneous mixing, (T2) relining-relief with PVC film and (T3) chairside digital impression - Cerec Conect Omnicam (Sirona). For each impression technique / casting time, 8 total impression were obtained by single calibrated operator (ICC = 0.99), with metal stock tray and condensation silicone (Speedex; Coltène / Whaledent Inc.) or addition (Express XT 3M ESPE). The gypsum casts pouring process were performed with type IV conventional gypsum (GC Fuji Rock EP - GC America) and zero expansion one (Zero Stone - Dentona AG). For impressions with condensation silicone the cast was poured after 30 minutes, 3 or 7 days. For the addition silicone impressions, the gypsum casts were obtained after 2 hours, 3, 7 or 15 days. For the three-dimensional analysis, a software was used to manage threedimensional images (Rhinoceros - version 5.3.2) allowing the investigation of virtual images (three-dimensional meshes) made with an optical laboratorial digitizer (R700 - 3Shape A/S) of the impressions and gypsum casts from T1 and T2, as well as, digital images acquired from T3. It were verified the results regarding the sample number with statistically significant power, distribution of the sample data and homoscedasticity. Afterwards, statistical methods were used (ANOVA 3-way and post hoc Tukey HSD) to evaluate the influence of the independent variables of the study, with significance level of 5.0%. Overall, as for the impressions results, the majority of the comparisons from the gypsum casts results did not present statistics differences between them. It is concluded that there is no difference between the experimental and baseline groups, for the precision of the impressions and gypsum casts obtained, regardless the impression technique, pouring time and type of gypsum stone used.
Descrição
Palavras-chave
Materiais para moldagem odontológica, Técnica de moldagem odontológica, Imagem tridimensional, Dental impression materials, Dental impression technique, Imaging three-dimensional