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INTRODUCTION: The complete bilateral cleft lip and palate (BCLP) divides the maxillary arch into three segments, separated from each other, resulting in abnormal growth of the alveolar arch. This study evaluated the maxillary arch dimensions in BCLP and compared them with neonates without craniofacial anomalies. METHODS: This retrospective study was conducted in a tertiary cleft centre. Sixty-six neonates aged 0-5 months were divided into two groups: cleft group-children with BCLP (23 boys and 18 girls) and control group-children without craniofacial deformities (15 boys and 10 girls). The dental models were processed by a 3D scanner. Landmarks were marked to achieve inter-canine distance, inter-tuberosity distance and arch length measurements. t-Tests were used for intergroup comparisons (p < .05). RESULTS: The maxillary cleft arch was demonstrated to be wider and longer in the posterior region compared to the control group. The inter-canine distance did not present differences between the cleft and controls. The inter-canine distance of the control group was the only measurement influenced by the variable sex. CONCLUSIONS: The cleft significantly interfered with the arch posterior width and arch sagittal length, making them larger. There was no statistical difference in the measurements between sex in the cleft group.

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ABSTRACT Introduction: The superimposition of 3 dimensions (3D) digital models has been increasingly used for evaluating dental changes resulting from orthodontic treatment, and different superimposition techniques have been described. Although the maxilla has areas with greater stability for superimposition, such as the palatal rugae, there is still no reliable method for superimposing models of the lower arch. Objective: Therefore, this article aims to describe a technique for superimposing virtual models. Methods: To evaluate pre- and post-orthodontic treatment changes, the Geomagic Qualify 2013 software (3D Systems®, Rock Hill, South Carolina, USA) was used, with reference points in the maxilla, including the rugae and a reference area in the palate and midpalatal raphe. The lower arch was superimposed using the maximum habitual intercuspation (MHI) model as reference. Results and Conclusion: 3D models superimposition using palatal rugae and MHI occlusion seems to offer satisfactory results in the interpretation of clinical changes at different follow-up moments in terms of development and/or orthodontic treatment.

RESUMO Introdução: A sobreposição de modelos digitais em três dimensões (3D) tem sido cada vez mais utilizada como forma de avaliar as alterações dentárias decorrentes do tratamento instituído, e diferentes técnicas de sobreposição têm sido descritas. Apesar de a maxila apresentar áreas de maior estabilidade para sobreposição dos modelos, como as rugas palatinas, ainda não existe um método confiável para a sobreposição da arcada inferior. Objetivo: O presente artigo tem como objetivo descrever uma técnica de sobreposição de modelos virtuais. Métodos: Para avaliar as alterações pré e pós-tratamento ortodôntico, foi usado o software Geomagic Qualify 2013 (3D Systems®, Rock Hill, Carolina do Sul, EUA) , utilizando pontos de referência na maxila na região das rugas palatinas e uma área de referência na zona do palato e rafe palatina mediana. Já a arcada inferior foi sobreposta utilizando o modelo em máxima intercuspidação habitual (MIH) como referência. Resultados e Conclusão: A sobreposição de modelos utilizando as rugas palatinas e a oclusão em MIH parece oferecer resultados satisfatórios na interpretação das alterações clínicas entre momentos diferentes de acompanhamento, seja do crescimento/desenvolvimento e/ou resultados do tratamento ortodôntico.

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Aim: The aim of this study was to evaluate the accuracy of models of partially edentulous arches obtained by three-dimensional (3D) printing. Settings and Design: This was an in vitro study. Materials and Methods: Fifteen partially edentulous models were evaluated, using two methods of measuring dimensions: virtual, using the Standard Tessellation Language files of the models and software (control group), and physical, through printing the models and digital caliper (test group). For both methods, measurements were made regarding the dimensions of the teeth (width and length - buccal/lingual or palatal/occlusal) and distances between the teeth. Statistical Analysis Used: For the variable of linear measurements (width and length) and distances between teeth of the same hemiarch, the Wilcoxon test was used, while for the variable between opposite hemiarches, the paired t-test was used. Results: In the evaluation of the linear measurements, a significant difference was observed only when the width of the molar tooth was analyzed (P = 0.014). When the buccal length was measured, all teeth had linear measurements provided by the virtual method that was lower than the physical (P = 0.000), as well as the lingual/palatal length in incisors (P = 0.003) and molars (P = 0.009) and in total (P = 0.001). As for the analyses between teeth, no difference was identified between the measurements provided by the virtual method compared to the physical one. Conclusions: The 3D printer used to print partially edentulous models provided linear distortions in the teeth but without changes in the distances between teeth of the same hemiarch and between teeth of opposite hemiarches.

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Los modelos de estudio son un registro fundamental para el diagnóstico, el plan de tratamiento, la presentación de caso y la evaluación del progreso del tratamiento dental; son registros anatomofisiológicos de las arcadas dentarias que sirven para evaluar la dentición en los tres planos del espacio y la oclusión en la relación cúspide-fosa, en una dimensión estática y dinámica. Para obtener los modelos de estudio es imprescindible obtener impresiones totales con diversos materiales de impresión de los arcos dentarios, que reproduzcan fielmente todos los detalles anatómicos, para posteriormente obtener un modelo en yeso piedra. Los modelos obtenidos a partir de una impresión generalmente son a base de yeso odontológico, los cuales a pesar de sus mejoras aún conservan algunas características negativas como: baja resistencia a la fractura por impacto, baja resistencia al desgaste por abrasión, inestabilidad dimensional y radiopacidad que impide la simulación de procedimientos endodóncicos. Con la finalidad de mejorar la simulación en la práctica odontológica, se usa la resina epóxica que puede emplearse en la obtención de modelos, este material es más resistente y presenta una mayor resistencia a la abrasión; además es radiolúcido, por lo que es útil para la réplica de preparaciones y procedimientos de simulación endodóntica. Los detalles de la superficie obtenidos con resina epóxica son superiores a los obtenidos con yeso. El uso de simuladores es una herramienta educativa con la que se favorece la adquisición de ciertas habilidades, destrezas, técnicas y competencias necesarias para la formación de estudiantes o profesionales de odontología. En el presente trabajo se describe la técnica para la elaboración de modelos dentales didácticos en resina epóxica para utilizarlos en la enseñanza de la práctica odontológica (AU)

Study studies are a fundamental record for diagnosis, treatment plan, case presentation and evaluation of the progress of dental treatment. They are anatomo-physiological records of the dental arches to evaluate the dentition in the three planes of space and the occlusion in the cusp-fossa relationships, in a static and dynamic dimension. To obtain the study models, it is essential to obtain total impressions with various impression materials of the dental arches, which faithfully reproduce all the anatomical details, in order to later obtain a stone plaster model. Those obtained from an impression are generally based on dental plaster, which despite its improvements still retain some negative characteristics such as: low resistance to fracture by impact, low resistance to wear by abrasion, dimensional instability and radio opacity that prevents the simulation of endodontic procedures. In order to improve simulation in dental practice, the use of epoxy resin can be used to obtain models, this material is more resistant and has greater resistance to abrasion, it is radiolucent, which makes them Useful for replicating preparations and endodontic simulation procedures, the surface details obtained with epoxy resin are superior to those obtained with plaster. The use of simulators is an educational tool that favors the acquisition of certain abilities, skills, techniques and competencies necessary for the training of the student or professional in dentistry. In the present work, the technique for the elaboration of didactic dental models in epoxy resin to be used in the teaching of dental practice is described.(AU)

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OBJECTIVE: Compare changes in arch form after RME achieved by Expander with Differential Opening (EDO), Hyrax-type and Haas-type expanders. MATERIALS AND METHODS: Dental models were obtained from 61 patients aged 7-11 years before expansion (T1) and 6 months after the active phase when the appliances were removed (T2). The groups were formed according to the expander used: EDO (n = 18, mean age: 9.46 ± 0.82 years), Hyrax-type (n = 22, mean age: 9.62 ± 1.57 years) and Haas-type (n = 21, mean age: 9.29 ± 1.05 years). The expander`s activation protocol consisted of 7 mm, except for EDO`s anterior screw, which was 9 mm. The measurements of upper and lower intercanine distance, inter-first permanent molar, arch perimeter and length, maxillary canine and first-permanent molar inclination, and palatal depth were performed using the OrthoAnalyzer 3D software. Intergroup comparisons of T1 and between changes (T2-T1) were performed using ANOVA followed by Tukey. RESULTS: In the upper intercanine distance EDO provided a greater increase than Haas-type. In the distance between upper fist permanent molars EDO showed higher values than Haas-type and Hyrax-type. In the lower intercanine distance and maxillary arch length, Haas-type promoted higher increase than EDO. CONCLUSIONS: The EDO promoted greater transverse changes in anterior region than Haas-type and greater transverse changes in posterior region of the maxilla than both conventional expanders. The appliance used for RME influences dental arch changes after treatment; therefore, it is recommended to individualize the choice of expander depending on the clinical necessity of each case.

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ABSTRACT Context: Digital study models have become a safe and advantageous alternative for diagnosis and planning in dentistry. Despite the superior characteristics in comparison with traditional plaster models, professionals seem to resist the use of new technologies. Aims: To assess the level of knowledge and the use of digital models through a questionnaire applied to dental professionals. Methods: A questionnaire with 12 multiple-choice questions about plaster models, digital, and use of the 3Shape - 3D viewer software was answered by 76 orthodontists (42 women and 34 men; mean age =37.82 years (SD ± 7.60)) and 30 general dental surgeons (18 women and 12 men; mean age of 33.93 years (SD ± 8.45)) in Aracaju, Sergipe, Brazil. Data were tabulated in Excel spreadsheets and then analyzed using the SPSS statistical software version 20. An absolute analysis of frequency and percentage of responses was performed. Results: Most professionals reported using plaster models and claimed their low cost as justification for their use (P = 0.001). Aware of the benefits of digital models, professionals of both classes highlighted the facilitated storage and search for information as the main advantages, the cost and infrastructure as the main disadvantages. Regarding the use of the 3Shape - 3D viewer software, orthodontists showed better utilization of this resource than general dental surgeons (P = 0.0198). Conclusion: It verified that most professionals make use of plaster models. However, despite knowing the advantages of digital models, their cost is sees as a limiting factor for adherence to this technology.

RESUMO Contexto: Os modelos digitais de estudo têm se tornado uma alternativa segura e vantajosa para o diagnóstico e planejamento em odontologia. Apesar das características superiores em comparação aos modelos tradicionais de gesso, os profissionais parecem resistir ao uso de novas tecnologias. Objetivos: Avaliar o nível de conhecimento e a utilização de modelos digitais por meio de questionário aplicado a profissionais da área odontológica. Material e Métodos: Questionário com 12 questões de múltipla escolha sobre modelos de gesso, digitais e uso do software 3Shape - 3D viewer foi respondido por 76 ortodontistas (42 mulheres e 34 homens; idade média = 37,82 anos (DP = ± 7,60) ) e 30 cirurgiões-dentistas gerais (18 mulheres e 12 homens; média de idade de 33,93 anos (DP = ± 8,45)) em Aracaju, Sergipe, Brasil. Os dados foram tabulados em planilhas do Excel e posteriormente analisados no software estatístico SPSS versão 20. Foi realizada uma análise absoluta de frequência e percentual de respostas. Resultados: A maioria dos profissionais relatou utilizar modelos de gesso e alegou seu baixo custo como justificativa para seu uso (P = 0,001). Cientes dos benefícios dos modelos digitais, os profissionais de ambas as classes destacaram o armazenamento facilitado e a busca de informações como as principais vantagens, o custo e a infraestrutura como as principais desvantagens. Em relação à utilização do software 3Shape - 3D viewer, os ortodontistas apresentaram melhor aproveitamento desse recurso do que os cirurgiões-dentistas gerais (P = 0,0198). Conclusões: Verificou-se que a maioria dos profissionais faz uso de modelos de gesso. Porém, apesar de conhecer as vantagens dos modelos digitais, seu custo é visto como um fator limitante para a adesão a essa tecnologia.

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Introducción Para el diagnóstico acertado en el tratamiento de los pacientes de ortodoncia se requiere de una serie de exámenes auxiliares, que son herramientas esenciales en ortodoncia; sin embargo, encontramos cierto grado de dificultad para la valoración de asimetrías dentarias en los hemiarcos de cada arcada dentaria; la importancia de la correcta valoración de las asimetrías es ya ampliamente mencionada en diferentes estudios, porque nos ayudará con la localización co-rrecta, de los dientes en su arcada,al final del tratamiento En la actualidad existe poca literatura sobre los métodos para evaluar y diagnosticar las alteraciones por hemiarcos, especialmente en el plano transversal. Objetivo acer una revisión de literatura sobre los métodos de medición de las asimetrías dentarias intra-arco para poder identificar y cuantificar las alteraciones dentarias en los tres planos del espacio en su respectiva arcada dentaria, el Método para los términos de búsqueda de la información fueron: dental and facial asymmetry, molar asymmetry in ortho-dontics, arch width prediction indices, as well as transverse discrepancies, para tal efecto se empleó Pubmed, Medline, Scielo, Schoolar Google, de los cuales se recopilaron 80 artículos relacionados con nuestro tema de estudio y solo se eligieron 30 artículos y 6 libros de ortodoncia en los que se sustenta este artículo. Resultados En el presente artículo presentamos las herramientas con las que contamos para el diagnóstico de la asimetría dentaria intra-arcos como la placa de Sthmuch y la placa milimetrada de Korkhaus, y finalmente proponemos un método que nos permite cuantificar objetivamente la asimetría en los tres plano del espacio de una manera sencilla, reproducible y de fácil almacenaje en un computador. Conclusión La etapa del diagnóstico es importante porque permitirá obtener la mayor y mejor información de las alteraciones dentarias que presenta el paciente, siendo las alteraciones transversales las más difíciles de cuantificar por que la mayoría de los estudios e índices, ya que solo evidencian las distancias de dientes contra laterales, los cuales son datos limitados pero que aún así contribuyen en el diagnóstico, el método de la placa de Sthmuch, Korkhaus y Bernklau son propuesta para medir las asimetrías dentarias intraarcos, no en tanto es desgastador para el operador y sus resultados objetivos radica en la experiencia del operador; el método KLO nos permite cuantificar objetivamente la falta de sime-tría dentaria en cada arcada de una manera fácil, reproducible y de almacenaje en un computador o en un archivo.

Introduction The correct diagnosis in the treatment of orthodontic patients requires a series of auxiliary examinations, which are essential tools in orthodontics, however we found a certain de-gree of difficulty in assessing dental asymmetries in the hemiarchs of each dental arch; The im-portance of the correct assessment of asymmetries is already widely mentioned in different stud-ies, because it will help us with the correct location of the teeth in their arch, at the end of the treatment. Currently there is little literature on the methods to evaluate and diagnose hemiarchal alterations, especially in the transverse plane. Objective Is to review the literature on the methods of measuring intra-arch dental asymmetries in order to identify and quantify dental al-terations in the three planes of space in their respective dental arch. Method The search terms of the information were: dental and facial asymmetry, molar asymmetry in orthodontics, arch width prediction indices, as well as cross-sectional discrepancies. Pubmed, Medline, Scielo, Schoolar Google, of which 80 articles related to our study topic were collected and only 30 articles and 6 orthodontic books were chosen on which this article is based, Results Also in this article we present the tolos that we have for the diagnosis of intraarch dental asymmetry such as the Sth-much plate and the Korkhaus millimeter plate, and finally we propose a method that allows us to objectively quantify the asymmetry in the three space plan in a simple, reproducible way and easy to store on a computer. Conclusión The stage of diagnosis is important because it will allow obtain-ing the greatest and best information on the dental alterations that the patient presents, being the transversal alterations the most difficult to quantify because most studies and indices, since they only show the distances of Contralateral teeth, which are limited data but still contribute to the diagnosis, the Sthmuch, Korkhaus and Bernklau plate method are proposed to measure intra-arch dental asymmetries, not as it is wearisome for the operator and his patients. objective results lies in the experience of the operator; The KLO method allows us to objectively quantify the lack of dental symmetry in each arch in an easy, reproducible way that can be stored on a computer or in a file.

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Aim: To evaluate the accuracy and the validity of orthodontic diagnostic measurements, as well as virtual tooth transformations using a generic open access 3D software compared to OrthoAnalyzer (3Shape) software; which was previously tested and proven for accuracy. Methods: 40 maxillary and mandibular single arch study models were duplicated and scanned using 3Shape laser scanner. The files were imported into the generic and OrthoAnalyzer software programs; where linear measurements were taken twice to investigate the accuracy of the program. To test the accuracy of the program format, they were printed, rescanned and imported into OrthAnalyzer. Finally, to investigate the accuracy of editing capabilities, linear and angular transformation procedures were performed, superimposed and printed to be rescanned and imported to OrthoAnalyzer for comparison. Results: There was no statistically significant difference between the two groups using the two software programs regarding the accuracy of the linear measurements (p>0.05). There was no statistically significant difference between the different formats among all the measurements, (p>0.05). The editing capabilities also showed no statistically significant difference (p>0.05). Conclusion: The generic 3D software (Meshmixer) was valid and accurate in cast measurements and linear and angular editing procedures. It can be used for orthodontic diagnosis and treatment planning without added costs

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Este trabajo tuvo como objetivo conocer la fiabilidad de la impresora 3D (i3D) aditiva por Matriz de Proceso Digital de Luz (MDLP) Hellbot modelo Apolo®, a través de verificar la congruencia dimensional entre las mallas de modelos impresos (MMi) y su correspondiente archivo digital de origen (MMo), obtenido del software de planificación ortodontica Orchestrate 3D® (O3D). Para determinar su uso en odontología y sus posibilidades clínicas, fue comparada entre cinco i3D de manufactura aditiva, dos DLP, dos por estereolitografía (SLA) y una por Depósito de Material Fundido (FDM). La elección de las cinco i3D se fundamentó en su valor de mercado, intentando abarcar la mayor diversidad argentina disponible. Veinte modelos fueron impresos con cada i3D y escaneados con Escáner Intraoral (IOS) Carestream modelo 3600® (Cs3600). Las 120 MMi fueron importadas dentro del programa de ingeniería inversa Geomagic® Control X® (Cx) para su análisis 3D, consistiendo en la superposición de MMo con cada una de las MMi. Luego, una evaluación cualitativa de la desviación entre la MMi y MMo fue realizada. Un análisis estadístico cuidadoso fue realizado obteniendo como resultado comparaciones en 3d y 2d. Las coincidencias metrológicas en la superposición tridimensional permitieron un análisis exhaustivo y fácilmente reconocible a través de mapas colorimétricos. En el análisis bidimensional se plantearon planos referenciados dentariamente desde la MMo, para hacer coincidir las mediciones desde el mismo punto de partida dentaria. Los resultados fueron satisfactorios y muy alentadores. Las probabilidades de obtener rangos de variabilidad equivalentes a +/- 50µm fueron de un 40,35 % y de +/- 100µm un 71,04 %. Por lo tanto, te- niendo en cuenta las exigencias de congruencia dimensional clínicas de precisión y exactitud a las cuales es sometida nuestra profesión odontológica, se evitan problemas clínicos arrastrados por los errores dimensionales en la manufactura (Cam) (AU)

The objective of this study was to determine the reliability of the Hellbot Apollo® model additive 3D printer (i3D) by Matrix Digital Light Processing (MDLP) by verifying the dimensional congruence between the printed model meshes (MMi) and their corresponding digital source file (MMo), obtained from the Orchestrate 3D® (O3D) orthodontic planning software. A comparison was made between five i3D of additive manufacturing, two DLP, two by stereolithography (SLA), and one by Fused Material Deposition (FDM), to determine its use in dentistry and its clinical possibilities. The choice of the five i3D was based on their market value, trying to cover most of the Argentinean diversity available. Twenty models were printed with each i3D and scanned with Carestream Intraoral Scanner (IOS) model 3600® (Cs3600). The 120 MMi were imported into the reverse engineering program Geomagic® Control X® (Cx) for 3D analysis, consisting of overlaying MMo with each MMi. Then, a qualitative evaluation of the deviation between MMi and MMo. Also, a careful statistical analysis was performed, resulting in 3d and 2d comparisons. Metrological coincidences in three-dimensional overlay allowed a comprehensive and easily recognizable analysis through colorimetric maps. In the two-dimensional analysis, dentally referenced planes were proposed from the MMo, to match the measurements from the same dental starting point. The results were satisfactory and very encouraging. The probabilities of obtaining ranges of variability equivalent to +/- 50µm were 40.35 % and +/- 100µm 71.04 %. Therefore, considering the demands of clinical dimensional congruence, precision, and accuracy to which our dental profession it is subjected, clinical problems caused by dimensional errors in manufacturing (Cam) are avoided (AU)

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This study evaluated the palatal surface area in children with different oral clefts after primary surgeries and at five years of age. This longitudinal study was composed by 216 digital models: unilateral complete cleft lip (UCL), unilateral complete cleft lip and palate (UCLP), and complete cleft palate (CP). The models were analysed at four time periods: T1 (before cheiloplasty), T2 (before palatoplasty), T3 (after palatoplasty); and T4 - (at five years of age). Area of the dental arches was measured through stereophotogrammetry software. Measurements evaluated with Student's test and ANOVA followed by the Tukey test (p<0.05) (AQ 1). In the UCL group, the palatal surface area significantly increased among phases. In the primary surgery periods, UCLP and CP significantly decreased (p<0.001). Palatal area in the UCLP group was significantly greater than the CP group. Overall, no statistically significant differences occurred among groups. At T4, the area of the palate in the UCL group was significantly greater than the UCLP group and no significant differences occurred between UCLP and CP groups. This study suggests that cheiloplasty did not inhibit the growth of the palatal surface area in children with UCL and UCLP. Palatoplasty significantly decreased the palatal area in children with UCLP and CP, demonstrating a significant negative effect of palatal repair on maxillary growth. At five years, children with UCLP and CP had a significantly smaller palate area than those with UCL.

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OBJECTIVES: This study aimed to compare dimensional alterations of dental arches in children with unilateral complete cleft lip and palate before and after different techniques of primary plastic surgeries. MATERIALS AND METHODS: The sample was divided into two groups: group 1-cheiloplasty by Millard's technique and one-stage palatoplasty by von Langenbeck's technique; group 2-cheiloplasty by Millard's technique and two-stage palatoplasty: anterior palatoplasty by Hans Pichler's technique and posterior palatoplasty by Sommerlad's technique. Dental arches were evaluated before (T1), after the first phase (T2), and 1 year after the second phase (T3) of primary surgeries. Linear measurements and palatal area were assessed. To analyze the method's error, interclass correlation coefficient was applied. ANOVA (followed by Tukey test), dependent, and independent t-test were used (p < 0.05). RESULTS: At T1, the intertuberosity distance was statistically greater in G2 (p = 0.004). At T2, the anterior length of the dental arch was statistically greater in G2 (p = 0.025), while the area of the smaller palatal segment (p = 0.001), cleft area (p = 0.014), and total area (p = 0.002) were statistically smaller in G2. At T3, the intertuberosity distance was statistically greater in G2 (p = 0.017). CONCLUSION: This study suggests that cheiloplasty and one-stage palatoplasty resulted in smaller growth of maxilla than cheiloplasty and two-stage palatoplasty in the linear measurements (T-T' and I-CC') and total area of the dental arches. CLINICAL RELEVANCE: Surgical protocols need to be evaluated to verify their effects aiming at improving the clinical practice of the interdisciplinary team, determining new parameters for the rehabilitation of individuals with cleft lip and palate.

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OBJECTIVE: To compare and assess the reproducibility of 3 methods for registration of maxillary digital dental models in patients with anterior open bite. Settings and sample population Digital dental models of 16 children with an anterior open bite in the mixed dentition were obtained before (T1) and after 12 months of treatment with bonded spurs (T2). METHODS: Landmarks were placed on all T2 models and 3 registration methods (R1, R2 and R3) were independently performed by 2 observers. R1 was based on 10 landmarks placed on posterior teeth. R2 was based on 5 landmarks on the palate (2 anterior, 2 posterior and 1 central). R3 used regions of interest around the 5 palatal landmarks used in R2. The differences between the registration methods were calculated by comparing the mean differences and standard deviations between the corresponding x, y and z coordinates of 6 corresponding landmarks in the T2 registered models. Repeated measures analysis of variance followed by post-hoc Bonferroni tests were used for comparisons (P < .05). The agreement between methods and the intra and interobserver reproducibility were assessed with Bland-Altman tests and intraclass correlation coefficients (ICC). RESULTS: Comparisons of R2 with R3 methods showed greater agreement, mean differences ≤0.50 mm for all landmarks, than comparisons of R1 with R2, and R1 with R3, mean differences >0.50 mm for most of the y and z coordinates (P < .05). The R1 and R3 methods presented excellent intra and interobserver reproducibility and R2 method had moderate interobserver reproducibility. CONCLUSIONS: Longitudinal assessments of open bite treatment using digital dental models could consider the posterior teeth and/or the palate as references. The R1 and R3 methods showed adequate reproducibility and yield different quantitative results. The choice will depend on the posterior teeth changes and dental models' characteristics.

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O uso de alinhadores transparentes tem se tornado um fenômeno mundial na clínica ortodôntica e muitos esforços e recursos têm sido consumidos para que o resultado do tratamento seja o mais acurado possível. Em 2021 a Invisalgn® lançou protocolo G8 prometendo melhor previsibilidade no tratamento. É através da sobreposição de imagens que estes resultados podem ser avaliados. Na literatura, encontram-se relatos de diversos métodos e softwares que buscam confiabilidade para sobreposição de modelos tridimensionais (3D), entretanto não há consenso sobre estes métodos. Desta forma, os objetivos deste estudo foram: (1) Desenvolver novo método de sobreposição de modelos 3D com Autodesk Inventor®, (2) avaliar a reprodutibilidade do Autodesk Inventor® utilizando o sistema de coordenadas universais (UCS) associado a único ponto para sobreposição de modelos ortodônticos 3D da mandíbula e maxila, (3) avaliar a reprodutibilidade do Autodesk Inventor® na sobreposição de modelo ortodôntico 3D da maxila e mandíbula, (4) Comparar a acurácia do protocolo G8 através do resultado previsto pelo ClinCheck® com o resultado real obtido nos movimentos de intrusão e expansão dentária posterior. Para responder os objetivos 1, 2 e 3, foram selecionados 11 pares de modelos em STL (estereolitografia) de ambos os arcos exportados pelo software My Itero® e tratados com Invisalign® em dois tempos: início (T0) e refinamento (T1). As sobreposições foram realizadas utilizando os softwares Slicer® (versão 4.1) e Autodesk Inventor® usando como referência os planos dos 3 eixos cartesianos UCS (X, Y e Z) associado a um ponto na segunda ruga palatina na maxila e, na mandíbula, um ponto na linha muco gengival lingual. Após a sobreposição os movimentos de translação buco-lingual dos caninos, pré-molares e molares superiores e inferiores, intrusão, rotação dos caninos e incisivos mandibulares foram analisados por dois examinadores calibrados. Para responder o objetivo 4, a acurácia foi comparada nos movimentos alcançados e previstos pelo ClinCheck® entre três casos em que o protocolo G8 foi ativado e 8 casos em que não foi ativado para a expansão posterior maxila e mandíbula, intrusão de caninos e incisivos inferiores. Os resultados do objetivo 1, 2 e 3 foram coeficientes de correlação intraclasse (ICC) maior que 0,90 em todas as medidas, não foi observado erro sistemático avaliado pela fórmula de Dahlberg. Nos resultados do objetivo 4 não foram observadas diferenças estatísticas significativas entre os grupos. A acurácia no grupo G8 quando comparada ao grupo não G8 para expansão posterior na mandíbula e maxila aumentou 12.7% e 7,8% respectivamente, mas não houve diferenças estatísticas significante. Para o movimento de intrusão, a acurácia do grupo G8 foi 7,7% maior que a do grupo não G8 sem diferença estatística entre eles. Não foram observadas diferenças estatísticas significativas nos movimentos dos dentes dos grupos G8 e não G8. Concluiu-se que o método desenvolvido se mostrou reprodutível para sobreposição de modelos tridimensionais. O protocolo G8, quando ativado, não apresenta maior acurácia para o tratamento com Invisalign®.

The use of clear aligners has become a worldwide phenomenon in orthodontic practice and much effort and resources have been expended to ensure that the treatment outcome is as accurate as possible. In 2021 Invisalgn® released the G8 protocol promises better treatment predictability. It is through image superimposition that these results can be evaluated. In the literature, there are reports of various methods and software that seek reliability for superimposing three-dimensional (3D) models, but there is no consensus on these methods. Thus, the objectives of this study were: (1) Develop a new method for superimposing 3D models with Autodesk Inventor®, (2) evaluate the reproducibility of Autodesk Inventor® using the universal coordinate system (UCS) associated with a single point for superimposing 3D orthodontic models of the mandible and maxilla (3) Evaluate the reproducibility of Autodesk Inventor® in superimposing orthodontic 3D models of the maxilla and mandible, (4) Compare the accuracy of the G8 protocol through the result predicted by ClinCheck® with the actual result obtained in intrusion movements and posterior dental expansion. To answer the objectives 1, 2 and 3, 11 pairs of STL (Stereo- lithography) models of both arches exported by My Itero® software and treated with Invisalign® were selected at two times: initial (T0) and refinement (T1). The superpositions were performed using the Slicer® (version 4.1) and Autodesk Inventor® software using as reference the planes of the three Cartesian axes (X, Y and Z) associated with a point on the second palatal crease in the maxilla and, in the mandible, a point on the lingual mucous gingival line. After superimposition, the bucco-lingual translation movements of the canines, premolars and upper and lower molars, intrusion, rotation of the canines and mandibular incisors were analyzed by two calibrated examiners. To answer the objective 4, the accuracy was compared in the movements achieved and predicted by ClinCheck® between three cases in which the G8 protocol was activated and 8 cases in which it was not activated for maxillary and mandibular posterior expansion, canine and mandibular incisor intrusion. The results of objectives 1, 2 and 3 were intraclass correlation coefficients (ICC) greater than 0.90 in all measurements, no systematic error evaluated by the Dahlberg formula was observed. In the results of objective 4, no statistically significant differences were observed between the groups. The accuracy in the G8 group when compared to the non-G8 group for posterior expansion in the mandible and maxilla increased by 12.7% and 7.8% respectively but without statistically significant differences. For intrusion movement, the accuracy of the G8 group was 7.7% higher than the non G8 group with no statistical difference between groups. No statistically significant differences were observed in the tooth movements of the G8 and non-G8 groups. It was concluded that the developed method proved reproducible for three- dimensional model superimposition. The G8 protocol, when activated, does not present greater accuracy for treatment with Invisalign®

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Resumo Objetivo: Esse estudo teve como objetivo comparar a acurácia de mensurações lineares realizadas, de acordo com o método de Moyers, em modelos de gesso pelo método manual com paquímetro em modelos digitais 3D digitalizados por scanner de mesa e em modelos digitais 3D obtidos por Tomografia Computadorizada Multislice com protocolo CTdBem. Método: Um único operador selecionou 90 modelos de gesso da arcada inferior para análise de dentição mista. Os métodos testados e o método manual foram comparados usando o teste-t pareado. Para avaliar o acordo entre os métodos, a correlação de Pearson foi utilizada. O gráfico de Bland-Altman foi construído para avaliar a diferença entre as medidas de cada amostra. Resultados: Não houve diferenças significativas entre as medidas do scanner e da Tomografia Computadorizada Multislice, quando comparadas com as medidas do método manual (p>0.05). Ambos os métodos digitais apresentaram correlação alta e significativa com o método manual com coeficientes de 0,98 e 0,97 para o scanner e a Tomografia Computadorizada Multislice, respectivamente (p<0.01). Conclusão: Os modelos digitais obtidos por scanner de mesa e por Tomografia Computadorizada Multislice com protocolo CTdBem produziram medidas lineares e com boa acurácia, compatíveis com as medidas manuais realizadas em modelo de gesso. (AU)

Abstract Aim: This study has aimed to compare the accuracy of linear measurements made, according to the Moyers method, on plaster casts by the manual method using a pachymeter in digital 3D models digitalized by a desktop scanner and in 3D digital models scanned by Multislice Computed Tomography using the CTdBem protocol. Method: A single operator has selected 90 plaster casts of the mandibular arch for analysis of mixed dentition. The methods tested and manual method were compared by using the paired t-test. To assess the agreement between the methods, Pearson's correlation was performed. The Bland-Altman plot was built to evaluate the difference among the measurements for each sample. Results: There were no significant differences between scanner and Multislice CT measurements when compared to the manual method measurements (p> 0.05). Both digital methods have had a high and significant correlation with the manual method with coefficients of 0.98 and 0.97 for the scanner and Multislice CT method, respectively (p<0.01). Conclusions: The digital models obtained by means of the desktop scanner and Multislice Computed Tomography by means of CTdBem protocol produced linear measurement and with good accuracy, compatible with the manual measurements made on plaster casts (AU)

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ABSTRACT Introduction: Currently, no method is considered effective for the evaluation of digital models in the Certification Examination of the Brazilian Board of Orthodontics (BBO), considering the parameters of the currently used manual method. Objective: Thus, the aim of this study is to verify the reliability of an evaluation method for digital models that could be used in the BBO exam, compared to the gold standard. Methods: Measurements were performed by five previously calibrated examiners. Samples of ten sets of plaster models of the final phase of orthodontic treatment were measured using a manual method (Objective Grading System, OGS). These models were digitized using a 3D scanner and exported to Geomagic Qualify software, in which the measurements were made with the proposed digital method. These measurements were repeated using five models, after fifteen days. The intra-examiner performance with this method was analyzed with a paired t-test, whereas the inter-examiner analysis was carried out with analysis of variance and Tukey's test. To compare the manual and digital methods, a paired t-test and Pearson's correlation analysis were performed. Results: A statistically significant difference was found. The results showed that, when compared to the manual method, the digital method was effective in measuring the OGS in four of the seven variables studied: Marginal Ridge, Overjet, Occlusal Contact, and Interproximal Contact. The variables Alignment, BL inclination, and Occlusal Relationship showed a great amount of dispersion in the findings. Conclusion: Further studies are needed to develop an adequate digital methodology that can be used for all OGS variables.

RESUMO Introdução: Ainda não há um método considerado eficaz para análise dos modelos digitais no exame do Board Brasileiro de Ortodontia (BBO), considerando-se os parâmetros do método manual atual. Objetivo: Assim, o presente estudo objetiva verificar a confiabilidade de um método de avaliação em modelos digitais para o exame do BBO, comparando com o padrão-ouro. Métodos: As medições foram realizadas por 5 examinadores, previamente calibrados. A amostra de 10 pares de modelos de gesso da fase final do tratamento ortodôntico foi medida no método manual (Sistema Objetivo de Avaliação, SOA). Os modelos foram digitalizados por meio de um scanner 3D e exportados para o software Geomagic Qualify, onde foram feitas as medidas no método digital proposto. As medidas foram refeitas em 5 modelos após 15 dias. A análise intraexaminador desse método foi realizada por meio do teste t pareado; já a interexaminadores, feita com ANOVA e teste de Tukey, sendo encontrada diferença estatisticamente significativa. Para a comparação dos métodos manual e digital, foram utilizados o teste t pareado e a correlação de Pearson. Resultados: Uma diferença estatisticamente significativa foi encontrada. Os resultados mostraram que, comparada ao método manual, a metodologia digital mostrou-se eficaz para medição do SOA em quatro das sete variáveis estudadas: Margem interproximal, Sobressaliência, Contato oclusal e Contato interproximal. As variáveis Alinhamento, Inclinação V-L e Relação oclusal mostraram muita dispersão nos achados. Conclusão: Mais estudos são necessários para o desenvolvimento de uma metodologia digital adequada em todas as variáveis do SOA.

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This study aimed to compare the trueness and precision of physical models manufactured chairside (intraoral scanner and 3D printed) or by plaster models obtained using impression with alginate or addition silicone. A full- arch stainless steel die was impressed to obtain ten physical models for each group. The models were measured in a stereomicroscope, considering four linear distances. To assess the precision accuracy, an analysis of the measurement variability was carried out, identified by the coefficients of variation and by the Levene's test to compare the groups. To analyze trueness, the data average was subtracted from the database and compared considering alpha as 5 %. Considering precision, the higher dispersion of data occurred in the models obtained with silicone impression. And for trueness, Kruskal Wallis and Dunn tests results did not indicate differences between the groups in the anteroposterior linear distances (p> 0.05). Only in anterior transverse distance obtained through TRIOS (0.31 mm), it presented lower accuracy compared to the models from silicone impression (0.13 mm); however, at transverse posterior distance, the models from silicone impression showed the lowest accuracy (p 0.05). The physical dental models obtained by digital and analog workflows showed acceptable dimensional accuracy expressed by high precision and trueness. There is no difference between the evaluated intraoral scanner systems and the impression materials for the full-arch impression.

Este estudio tuvo como objetivo comparar la veracidad y precisión de modelos físicos fabricados en la clínica dental (escáner intraoral e impreso en 3D) o por modelos de yeso obtenidos mediante impresión con alginato o silicona de adición. Una matriz de acero inoxidable de arco completo fue impresa para obtener diez modelos físicos para cada grupo. Los modelos se midieron en un estereomicroscopio, considerando cuatro distancias lineales. Se realizó un análisis de la variabilidad de la medida para evaluar la precisión, identificada por los coeficientes de variación y por la prueba de Levene para comparar los grupos. Para analizar la veracidad, el promedio de los datos se restó de la base de datos y se comparó considerando alfa como 5 %. Considerando la precisión, la mayor dispersión de datos ocurrió en los modelos obtenidos con impresión de silicona. Y para la veracidad, los resultados de las pruebas de Kruskal Wallis y Dunn no indicaron diferencias entre los grupos en las distancias lineales anteroposteriores (p> 0,05). Solo en la distancia transversal anterior obtenida mediante TRIOS (0,31 mm) presentó menor precisión en comparación con los modelos de impresión de silicona (0,13 mm); sin embargo, la distancia transversal posterior, los modelos de impresión de silicona mostraron la menor precisión (p 0,05). Los modelos dentales físicos obtenidos mediante flujos de trabajo digitales y analógicos mostraron una precisión dimensional aceptable expresada por alta precisión y veracidad. No se observó diferencia entre los sistemas de escáner intraoral evaluados y los materiales de impresión para la impresión de arco completa.

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The aim of this study was to evaluate the usability of the free software available that allow visualization and measurement of orthodontic digital models. 80 graduate students of orthodontics were asked to perform pre-defined tasks in a digital model through 3D Viewer ® and 3D-Tool ® software. The success in accomplishing the tasks and the time spent were recorded. To end, each participant answered a questionnaire to express their satisfaction regarding the software. There were no statistically significant difference between the software when compared to the accomplishment rates of tasks and the time spent by participants on each one. The software were evaluated as "slightly satisfactory" in several criteria. There is scope for optimization of orthodontic software by manufacturers since lack of their interface usability can discourage orthodontists' adherence to new resources that could provide benefits to their daily routine, even if they are freely available.

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A tecnologia vem ganhando espaço de maneira acelerada em todas as áreas do conhecimento, não sendo diferente na Odontologia. Na Ortodontia, o correto planejamento exige a utilização de exames complementares, como radiografias, fotografias intra e extraorais, traçados cefalométricos e modelos das arcadas dentárias. Tradicionalmente, os modelos são confeccionados em gesso e obtidos através de uma moldagem com alginato de toda a arcada do paciente. Contudo, a substituição de modelos em gesso por modelos digitais é uma realidade na Odontologia contemporânea, especialmente por possuir vantagens como facilidade de acesso, armazenamento e transferência, e precisão da captura de imagens técnicas. Trata-se de um estudo observacional transversal, que avaliou a acurácia de mensurações lineares, realizadas por ortodontistas, em modelos digitais obtidos por meio de escaneamento direito e imagens de tomografia computadorizada de feixe cônico (TCFC). Alterações clínicas simuladas, com a presença de objetos metálicos, foram realizadas para verificar uma possível interferência nas mensurações e, além disso, foi testada a eficácia da ferramenta de redução de artefatos metálicos (RAM), presente no exame de TCFC. A amostra foi composta por 15 ortodontistas que atuaram como examinadores do estudo, sendo responsáveis pela realização das mensurações nos modelos. Dois crânios secos, com os dentes íntegros, foram utilizados para obtenção dos modelos digitais. Foram utilizados o teste t pareado, para a análise comparativa das mensurações entre examinadores e padrão-ouro, assim como para correlação intraclasse, e o Modelo de Equações de Estimativas Generalizada (Modelo GEE) para verificar se a experiência dos examinadores e uso rotineiro dos modelos digitais interferia na acurácia das mensurações. Os dados obtidos foram tabulados e analisados utilizando o programa SPSS, com o nível de significância 5%. Os ortodontistas apresentaram alta correlação intra-examinador para praticamente todas as variáveis testadas (média de 0,88), exceto nos parâmetros "distâncias intermolares" (média de 0,37) e "discrepância de Bolton" (média de 0,31). Quando as mensurações foram comparadas com o padrão-ouro, os valores encontrados pelos examinadores diferiram estatisticamente em todos os parâmetros testados, em pelo menos um dos modelos obtidos, porém essas diferenças não apresentaram relevância clínica. Nos quesitos tempo de experiência e uso rotineiro de modelos digitais, os grupos estudados não apresentaram diferenças na maioria dos parâmetros avaliados. Além disso, não foram encontradas diferenças nas mensurações realizadas em modelos com metal, com e sem a utilização da ferramenta RAM. Conclui-se que os ortodontistas são capazes de realizar mensurações acuradas em modelos digitais, independente da prática rotineira com essa tecnologia, e o tempo de experiência na especialidade favorece a realização de mensurações mais precisas. As alterações clínicas simuladas com a presença de objetos metálicos, não prejudicaram a análise acurada dos modelos. No entanto, a ferramenta RAM não facilitou a realização das mensurações nos modelos extraídos da TCFC que possuíam objetos metálicos. (AU)

Technology has been gaining ground in an accelerated way in all areas of knowledge, being no different in Dentistry. In Orthodontics, correct planning requires the use of complementary exams such as radiographs, intra and extraoral photographs, cephalometric tracings, and dental arch models. Traditionally, the models are made in plaster and escape through the molding with alginate of all the patient's arch. However, the replacement of plaster models by digital models is a reality in contemporary Dentistry, especially for having advantages such as ease of access, storage and transfer, and precision in capturing technical images. This is a cross-sectional observational study, which evaluated the accuracy of linear measurements performed by orthodontists, in digital models used through straight scanning and cone beam computed tomography (CBCT) images. Simulated clinical alterations, with the presence of metallic objects, were carried out to verify a possible interference in the measurements and, in addition, the metallic artifact reduction tool (MAR), present in the CBCT exam, was tested. The sample consisted of 15 orthodontists who acted as examiners for the study, being performed by carrying out measurements in the models. Two dry skulls, with intact teeth, were used to obtain the digital models. The paired t-test was used for a comparative analysis of measurements between examiners and the gold standard, as well as for intraclass correlation, and the Generalized Estimating Equation Model (GEE Model) to verify whether the experience of examinations and routine use of digital models interfered with the accuracy of the measurements. The data gathered were tabulated and the SPSS program used throughout with a 5% significance level. The independent orthodontists had high intra-examiner correlation for practically all variables tested (mean of 0.88), except for the parameters "intermolar distances" (mean of 0.37) and "Bolton discrepancy" (mean of 0.31). When the measurements were compared with the gold standard, the values found by the examiners differed statistically in all tested parameters, in at least one of the required models, but these differences did not parallel clinically. In terms of experience time (years) and routine use of digital models, the studied groups did not differ in most of the parameters adopted. Furthermore, no differences were found in the measurements performed on metal models, with and without the use of the MAR tool. It is concluded that orthodontists can perform accurate measurements on digital models, regardless of their routine practice with this technology, and the length of experience in the specialty favors the performance of more accurate measurements. The clinical changes simulated with the presence of metallic objects did not affect the accurate analysis of the models. However, a MAR tool did not facilitate the performance of measurements in models extracted from CBCT that had metallic objects. (AU)

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ABSTRACT Objective: The objectives of the present study were to develop a method for longitudinally measuring tooth rotation, inclination and angulation on digital models, and to test the method validity and reliability. Methods: The initial and final planned models of 14 patients treated with Invisalign® (386 teeth) were exported from ClinCheck®. The rotation, inclination and angulation values were assessed for the incisors, canines, premolars and molars, in both models, using trigonometry. An application was developed in Python 2.7 to automate the measurements. The ∆planned (variation in the position between the initial and final planned models) was obtained for each tooth and each type of movement. To test the validity, the degree of agreement between the ∆planned and the values available in the Invisalign® Table of Movements was assessed using the Intraclass Correlation Coefficient (ICC) and Bland-Altman analysis. For intra and inter-rater reliabilities, the ∆planned was obtained again. Results: Excellent ICCs (> 0.9) and limits of agreement with narrow and clinically acceptable discrepancies were obtained for the rotation of all teeth (except maxillary canines, which had broader limits: -3.47 - 5.43) and for the inclination of premolars and molars. The inclination of anterior teeth and angulation of all teeth had ICCs and limits that were not indicative of great agreement. The reliability was high for the three movements (discrepancy <2°). Conclusions: The method developed is reliable and suitable for longitudinally measuring inclination (posterior teeth) and rotation (except maxillary canines). It has limited value for the other movements measurements.

RESUMO Objetivo: Os objetivos do presente estudo foram desenvolver um método para medir longitudinalmente a rotação, inclinação e angulação dentárias em modelos digitais, e testar sua validade e reprodutibilidade. Material e Métodos: Os modelos inicial e final planejado de 14 pacientes tratados com Invisalign® (386 dentes) foram exportados do ClinCheck®. Os valores de rotação, inclinação e angulação foram calculados para incisivos, caninos, pré-molares e molares, em ambos os modelos, por meio de trigonometria. Um aplicativo desenvolvido em Python 2.7 foi utilizado para automatização das medidas. O ∆planejado (variação na posição entre os modelos inicial e final planejado) foi obtido para os movimentos descritos, nos diferentes grupos de dentes. A validade do método foi verificada pelo grau de concordância entre o ∆planejado e os valores disponíveis na Tabela de Movimentos do Invisalign®, utilizando-se o Coeficiente de Correlação Intraclasse (ICC) e a análise de Bland-Altman. O ∆planejado foi novamente calculado para análise da reprodutibilidade intra e interexaminadores. Resultados: Excelentes ICCs (> 0,9) e limites de concordância com discrepâncias reduzidas e clinicamente aceitáveis foram obtidos para a rotação de todos os dentes (exceto os caninos superiores, que expressaram limites mais amplos: -3,47 - 5,43) e para a inclinação de pré-molares e molares. A inclinação dos dentes anteriores e a angulação de todos os dentes apresentaram ICCs e limites não representativos de boa concordância. A reprodutibilidade foi alta para os três movimentos (discrepância < 2°). Conclusões: O método desenvolvido é reprodutível e se mostrou adequado para mensuração longitudinal da inclinação de dentes posteriores e rotação de todos os dentes, exceto caninos superiores. Apresenta valor limitado para as demais mensurações.

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ABSTRACT The aim of this study was to evaluate the precision and accuracy of molds made with four commercial brands of alginate scanned at different times using digital model analysis. Eighty molds of a standard Typodont were made using 4 types of alginate (CCC: Cavex Color Change; IA: Identic Alginate; HY5: Hydrogum 5 and JP: Jeltrate Plus). The molds were scanned at four times: immediately (T1), 24h (T2), 72h (T3) and 120h (T4) after molding. Measurements were taken in three dimensions: anteroposterior, transverse and vertical. Significant differences in dimensional changes were noted between the materials over time (p <0.05). Anteroposterior dimensional variation was noted between times, especially for IA and JP. For transverse and vertical variables, a difference was found between the groups, especially at 24 h, 72 h and 120 h. CCC presented significant dimensional shrinkage only at T120 (transverse). IA and JP presented larger dimensional distortions in the vertical measurements. The molding materials used were not dimensionally stable when evaluated after 120 hours of molding. However, such evidence suggests that alginates with longer storage time, such as Cavex Color Change, are more accurate than conventional alginates.

RESUMO O objetivo do presente estudo foi avaliar a precisao e acurácia por meio de análise de modelos digitais de moldes digitalizados obtidos com quatro marcas comerciais de alginato em diferentes tempos. Oitenta moldes de um Typodont padrao foram obtidos utilizando 4 tipos de alginato (CCC: Cavex Color Change; IA: Identic Alginate; HY5: Hydrogum 5 e JP: Jeltrate Plus). Os moldes foram escaneados em quatro tempos: mediatamente (T1), 24h (T2), 72h (T3) e 120h (T4) após a moldagem. As medidas foram feitas em très dimensoes: ântero-posterior, transversal e vertical. Diferenças significativas nas mudanças dimensionais foram observadas entre os materiais ao longo do tempo (p <0,05). Variação dimensional ântero-posterior foi observada entre os tempos, principalmente para IA e JP. Para as variáveis transversal e vertical houve diferenga entre os grupos, principalmente em 24h, 72h e 120h. CCC apresentou contração dimensional significativa apenas em T120 (transversal). IA e JP apresentaram maiores distorções dimensionais na vertical. Os materiais de moldagem utilizados nao foram dimensionalmente estáveis quando avaliados após 120 horas de moldagem. No entanto, tais evidencias sugerem que os alginatos com maior tempo de armazenamento, como Cavex Color Change, sao mais precisos do que os alginatos convencionais.

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