Effectiveness of commercially available denture adhesives on retention of mandibular complete denture in resorbed mandibular ridge: an in vitro study / Efectividad de los adhesivos disponibles comercialmente sobre la retención de prótesis removibles completas mandibulares en el reborde mandibular reabsorbido: un estudio in vitro

Background: Denture adhesives are alternatives used to improve retention, stability, comfort and satisfaction in patients with complete dentures. Evidence on the effectiveness of denture adhesives on resorbed mandibular ridges is scarce. Among the many commercially available denture adhesives, the ideal material for the severely resorbed mandibular ridge remains in dispute. Objective: The aim of this study was to evaluate the effectiveness of different quantities of four commercially available denture adhesives on the retention of mandibular complete dentures in severely resorbed ridges. Materials and Methods: A resorbed edentulous mandibular ridge model was manufactured in acrylic resin. A denture base was made and three loops were attached to it. Four commercially available denture adhesives (Fixodent, Perlie White, Fiftydent and Polident) were tested in amounts of 0.2 g, 0.4 g, 0.6 g, 0.8 g and 1.0 g. The acrylic resin model was evenly moistened with 1 ml of water and a weighted amount of adhesive material was applied to the denture base. The universal testing machine engaged the loops fixed on the denture base and applied the vertical displacement force. The maximum vertical displacement force values were recorded for each denture adhesive material at different amounts. Statistical calculation was performed using Kruskal Wallis with Bonferroni post hoc correction. Results: Statistically significant differences were observed in the mean values of the vertical displacement force for adhesive amounts of 0.2 g, 0.4 g, 0.6 g and 1.0 g (p<0.05) between the four adhesive materials tested. Statistically significant differences were observed when four denture adhesives were compared to each other in different amounts (p<0.05). Statistically significant differences were observed between different amounts for each of four denture adhesives (p<0.05). Conclusions: Among the four materials tested, Polident showed greater effectiveness at 0.6 g and 0.8 g, Fittydent at 0.6 g, 0.8 g and 1 g, Fixodent at 0.4 g and 0.6 g and Perlie White at 1 g and 0.8g quantity to resist vertical displacement. forces on the severely resorbed mandibular crest. Using an appropriate amount of denture adhesive allows for proper retention of the denture; Replacement of this adhesive is necessary once a day.

Introducción: Los adhesivos para prótesis dentales son alternativas utilizadas para mejorar la retención, la estabilidad, la comodidad y la satisfacción en los pacientes con prótesis completas. La evidencia sobre la efectividad de los adhesivos para prótesis dentales en los rebordes mandibulares reabsorbidos es escasa. Entre los muchos adhesivos para prótesis dentales disponibles comercialmente, sigue estando en disputa cuál es el material ideal para el reborde mandibular severamente reabsorbido. Objetivo: El objetivo de este estudio fue evaluar la efectividad de diferentes cantidades de cuatro adhesivos para prótesis dentales disponibles comercialmente sobre la retención de prótesis dentales completas mandibulares en reborde mandibular reabsorbido severamente. Materiales y Métodos: Se fabricó un modelo de reborde mandibular edéntulo reabsorbido en resina acrílica. Se hizo una base para la prótesis y se le colocaron tres bucles. Se probaron cuatro adhesivos para dentaduras postizas disponibles comercialmente (Fixodent, Perlie White, Fiftydent y Polident) en cantidades de 0,2 g, 0,4 g, 0,6 g, 0,8 g y 1,0 g. El modelo de resina acrílica se humedeció uniformemente con 1 ml de agua y se aplicó la cantidad correspondiente de material adhesivo sobre la base de la dentadura. La máquina de prueba universal enganchó los bucles fijados en la base de la dentadura postiza y aplicó la fuerza de desplazamiento vertical. Se registraron los valores máximos de fuerza de desplazamiento vertical para cada material adhesivo para dentaduras postizas en diferentes cantidades. El cálculo estadístico se realizó utilizando Kruskal Wallis con corrección post hoc de Bonferroni. Resultado: Se observaron diferencias estadísticamente significativas en los valores medios de la fuerza de desplazamiento vertical para cantidades de 0,2 g, 0,4 g, 0,6 g y 1,0 g (p<0,05) entre los cuatro materiales adhesivos para prótesis dentales probados. Se observaron diferencias estadísticamente significativas cuando se compararon cuatro adhesivos para prótesis dentales entre sí en diferentes cantidades (p<0,05). Se observaron diferencias estadísticamente significativas entre diferentes cantidades en los cuatro adhesivos para prótesis (p<0,05). Conclusión: De los cuatro materiales probados, Polident mostró mayor efectividad a 0,6 g y 0,8 g, Fittydent a 0,6 g, 0,8 g y 1 g, Fixodent a 0,4 g y 0,6 g y Perlie White a 1 g y 0,8 g para resistir fuerzas de desplazamiento vertical en la cresta mandibular severamente reabsorbida. El uso de una cantidad adecuada de adhesivo para dentaduras postizas permite una retención adecuada de la dentadura postiza; El reemplazo de este adhesivo es necesario una vez al día.

Utilisation des moyens de protection individuelle au laboratoire de prothèse dentaire: étude descriptive auprès de techniciens au Sénégal / Use of personal protective devices in dental laboratory: a descriptivestudy among senegalese technicians

Introduction : L'élaboration de prothèses dentaires nécessite la manipulation de plusieurs matériaux et produits chimiques favorisant l'exposition du Technicien de Laboratoire de Prothèse (TLP) à des risques professionnels. Cette étude avait pour objectif d'évaluer les moyens de protection utilisés par les TLP et le niveau de connaissance des risques. Matériel et Méthode : Il s'est agi d'une étude descriptive, transversale qui a inclus une population de 45 TLP sénégalais. Cette étude s'est basée sur un auto-questionnaire qui comportait des items sur les données sociodémographiques et professionnelles, la protection individuelle, et la connaissance des TLP sur les risques professionnels. L'analyse statistique des variables a été faite avec le logiciel Excel et SPSS. Résultats : Les TLP ont un âge moyen 41,73 ± 8, 03 ans, 82,20% sont des hommes et 68,9% exercent dans la région de Dakar. Tous les 45 TLP ayant répondu au questionnaire portent un vêtement de travail soit 100%. Seulement 5 soit 11,1% des TLP n'utilisent pas de protecteurs d'yeux et du visage. Pour les types de protecteurs, seulement 7,5% font usage d'écrans faciaux, 8,9% portent parfois des bouchons d'oreilles en guise de protecteurs auditifs. En ce qui concerne les gants, plus de la moitié des TLP les utilise, soit 60%. Les gants à usage unique sont les plus utilisés. Enfin, presque tous les TLP soit 97,8% ont connaissance des risques liés à leur métier. Conclusion : Cette étude révèle qu'au-delà des équipements de protection auditive qui sont peu utilisés par les techniciens de laboratoire, le port des vêtements de travail est systématique. L'usage des moyens de protection respiratoire, des yeux et du visage est généralisé, et la fréquence du port des gants sur le poste de travail de la décontamination est relativement élevée.

Background/aim: Development of dentures requires handling of several materials and chemicals put Prosthetic Laboratory Technicians (PLTs) at occupational risks. This study aimed to assess the level of risk awareness and the means ofprotection used by PLTs. Material and Method: It was a descriptive, cross-sectional study that included a population of 45 Senegalese PLTs. This study was based on a self-questionnaire that included four items including socio-demographic and occupational data, individual protection and knowledge of PLTs on occupational risks. The statistical analysis of the variables was done using the Excel and SPSS software, and the results presented as frequencies, averages with standard deviation.Results: Average age of PLT was 41,73 ± 8, 03 years and68,9% of them were working in Dakar city. Among these 45 TLPs with 82,20% men who responded to the questionnaire,100% wore a work garment, only 11.1% (or 5) TLPs do not use eye and face protectors against 88.9 (or 40). As for the typesof protectors, only 7.5% (or 3) of face shields. For hearing protectors, only 8.9% of TLPs sometimes wore earplugs. As forgloves, more than half of TLPs used them, or 60%. Disposable gloves are the most used at the expense of reusable gloves. Moreover, almost all TLPs, or 97.8%, are aware of the risks related to their business. Conclusion: This study reveals that in addition to hearing protection equipment that is rarely used by laboratory technicians, the wearing of work clothes is systematic. The use of respiratory, eye and face protection is widespread and frequency of wearing gloves on the decontamination workstation is relatively high

Protocolo Abreviado Guiado Digital: Técnicas de Marcadores Tisulares, Silicona de Registro y CBCT con Sonrisa / Digitally Guided Abbreviated Protocol: Tissue Marker Techniques, Recording Silicone and CBCT with Smile

Establecer un protocolo de cirugía guiada estática con técnicas referenciales para ser realizado de manera predecible, repetible y simple, en todos los tipos de casos. El protocolo abreviado guiado digital para cirugía guiada estática para implantes se centra en diseñar computacionalmente una guía quirúrgica que se apoye en el tejido remanente del paciente, siendo un protocolo digital versátil para la cirugía y rehabilitación implanto protésica, basada en registros clínicos, principalmente la línea de la sonrisa y la captación de ésta en tomografía de haz cónico (CBCT), además de establecer dimensión vertical oclusal (DVO). Logrando así, planificación de implantes hasta la inserción inmediata de la prótesis temporal. Se ejemplifica el trabajo con 2 casos clínicos. Se establece un protocolo con la intención de que pueda ser realizado en pacientes desdentados parciales (Técnica de Registro Silicona) o totales (Técnica de Marcadores Tisulares en prótesis), definiendo un flujo de trabajo tridimensional, digital y optimizado, con un consecuente ahorro de tiempo clínico. Como principio del protocolo de cirugía guiada es lograr el objetivo quirúrgico - protésico deseado con alta precisión. La cirugía y rehabilitación de implantes de manera convencional es altamente dependiente del operador por lo que la alternativa de cirugía guiada de manera estática es una herramienta más para mejorar el pronóstico del paciente. Se establece un protocolo digital simple y efectivo, de cirugía guiada, para la rehabilitación implanto protésica basada en la línea de la sonrisa, tomografía de haz cónico (CBCT), dimensión vertical oclusal (DVO). Protocolo predecible y que optimiza los tiempos clínicos, logrando una rehabilitación protésica inmediata acorde e individualizada para cada paciente.

Establish a static guided surgery protocol with referential techniques to be performed in a predictable, repeatable and simple way, in all types of cases. The abbreviated digital guided protocol for static guided surgery for implants focuses on computationally designing a surgical guide that rests on the patient's remaining tissue, being a versatile digital protocol for prosthetic implant surgery and rehabilitation, based on clinical records, mainly the line of the smile and its uptake in cone beam tomography (CBCT), in addition to establishing occlusal vertical dimension (OVD). Thus achieving implant planning until the immediate insertion of the temporary prosthesis. The work is exemplified with 2 clinical cases. A protocol is established with the intention that it can be carried out in partially edentulous patients (Silicone Registration Technique) or total (Tissue Marker Technique in prostheses), defining a three-dimensional, digital and optimized workflow, with a consequent saving of time. clinical. As a principle of the guided surgery protocol, it is to achieve the desired surgical-prosthetic objective with high precision. Conventional implant surgery and rehabilitation is highly dependent on the operator, so the alternative of statically guided surgery is one more tool to improve the patient's prognosis. A simple and effective digital protocol for guided surgery is established for prosthetic implant rehabilitation based on the smile line, cone beam tomography (CBCT), and occlusal vertical dimension (OVD). Predictable protocol that optimizes clinical times, achieving an immediate and individualized prosthetic rehabilitation for each patient.

Audit to assess the quality of 916 prosthetic prescriptions of removable partial dentures / 华西口腔医学杂志

OBJECTIVES@#The objectives of this study were to assess the quality of prosthetic prescriptions of removable partial dentures (RPDs) and to analyze the current situation of the communication and information delivery between clinicians and technicians.@*METHODS@#All RPD prosthetic prescriptions received by a major dental laboratory in 4 weeks were involved in a quality audit, and the prescriptions were divided into three groups in accordance with the grades of clients. The filling of prosthetic prescriptions was recorded. The items in the prescriptions for audit included the general information of the patient, the general information of the clinician, the design diagram information, other detailed information, and the return date. The prescriptions were categorized into four levels on the basis of their quality by two quality inspectors who have been working for more than 10 years.@*RESULTS@#A total of 916 prescriptions were collected and assessed. The names in the general information of the patient and the clinician were filled out best, both at the rate of 97.6% (n=894). The return date was filled out worst, only at the rate of 6.4% (n=59). Of those prescriptions, 86.8% (n=795) exhibited inadequate design diagram information. The results of the quality assessment demonstrated that 74.2% of prescriptions were assessed as noncompliant ones and failed to meet the acceptable clinical quality standard.@*CONCLUSIONS@#At present, the overall quality of RPD prosthetic prescriptions is poor. The responsibilities of clinicians and technicians are unclear, and the communication between them is not ideal.

A simplified technique for fabricating complete dentures for patients with Parkinson's disease: a case report / Técnica simplificada como alternativa para confecção de próteses totais para paciente com Doença de Parkinson: relato de caso

BACKGROUND AND OBJECTIVE: Parkinson's disease is a neurological disorder that affects 1% of individuals aged 60 years and older. The associated symptoms can impose limitations on the available dental treatment options. CASE DESCRIPTION: This case report follows the CARE guidelines and presents an adapted and simplified technique to fabricate complete dentures for a 74-year-old male edentulous patient with Parkinson's disease. This modified technique enabled the fabrication of complete dentures in 4 clinical sessions of approximately 40 minutes. The first session involved manufacturing a preliminary impression with fast-setting alginate. The base plates and occlusal rims were then adjusted for artificial teeth arrangement during the second session. The final prosthesis was completed in the third session, which involved a teeth try-in and fabrication of a functional impression with low-melting thermoplastic material and polyether. Finally, denture installation was performed in the fourth session and follow-up consisted of 3 weekly sessions. DISCUSSION: Considering that the treatment provided satisfactory aesthetics and function, mastication and socialization benefits, and improved the self-esteem and well-being of the older patient with Parkinson's disease, the authors suggest this adapted and simplified technique for fabricating complete dentures. (AU)

JUSTIFICATIVA E OBJETIVO: A doença de Parkinson é uma desordem neurológica que afeta 1% dos indivíduos com 60 anos ou mais. Os sintomas associados podem impor limitações nas opções de tratamento odontológico disponíveis. DESCRIÇÃO DO CASO: Este relato de caso segue o protocolo CARE e apresenta uma adaptação da técnica simplificada para confecção de novas próteses totais, para um paciente edêntulo, do sexo masculino, de 74 anos com doença de Parkinson. Essa técnica modificada possibilita a confecção de próteses totais em quatro sessões clínicas de aproximadamente 40 minutos. A primeira sessão envolveu uma moldagem preliminar com alginato de presa rápida. As placas articulares com rodetes de cera foram ajustadas para montagem dos dentes artificiais durante a segunda sessão. A prótese definitiva foi concluída na terceira sessão, que envolveu a prova dos dentes e moldagem funcional com material termoplástico de baixa fusão e poliéter. Por fim, a instalação da prótese foi realizada na quarta sessão e o acompanhamento consistiu em três sessões semanais. DISCUSSÃO: Considerando que o tratamento proporcionou estética e função satisfatórias, benefícios mastigatórios e de socialização, melhora da autoestima e bem-estar do idoso com doença de Parkinson, os autores sugerem o uso da adaptação da técnica simplificada para confecção de prótese total. (AU)

A review about the application of phonetic methods in deciding the jaws relation of complete denture / 华西口腔医学杂志

Speech could be used, because it was a neuromuscular movement without teeth contact. The method was stable, however it was used more in vertical relation deciding. More study was needed in the horizontal relation deciding. This article was to explain why and how to use phonetic method to decide jaws relation, through literature review.

Diseño de Sonrisa Digital / Digital Smile Desinge

Nowadays, a lot of people need in reconstruction of the teeth in connection with their loss. Before prosthetics or any other manipulations, a person wants to quickly see the aesthetic appearance of his future tooth. At the moment, many dentists use the option of verbal explanation to the patient, what will look like a smile or a front row of teeth after treatment, but the visual representation of the person remains aside. But now this can be achieved with the help of "Digital smile design", which shows the person the final result of the dentition. This technology has a number of advantages. Some of them are the rapid creation of a prototype model and high accuracy in the manufacture of work. Thanks to these technologies, communication between the specialist and the patient has been facilitated. The digital smile design has simplified the doctor's work process and reduced patient data processing time. From now on, achieving aesthetic results in the reconstruction of teeth for the dentist is not a problem.

Application of single-retainer all-ceramic resin-bonded fixed partial denture in the maintenance of missing incisor gap after orthodontic treatment in adolescents: a case report / 华西口腔医学杂志

This article reports a case of an orthodontic adolescent patient without a right inferior incisor. The right lower canine was used as the abutment. The single-retainer all-ceramic resin-bonded fixed partial denture was used to restore the complete dentition. Thus, the missing space was filled, and the function and aesthetics were restored.

A technique to design the framework of removable partial denture by multi-stage expert system / 华西口腔医学杂志

This study aims to apply a new expert system to design removable partial denture (RPD) framework. The RPD design is completed in three steps, namely, "selecting missing teeth", "selecting abutment condition", and "selecting personalized clasp". The system can help auxiliary dentists develop personalized treatment plans to reduce their clinical workload. It can also generate a dental preparation guideline for clinical preparation, which can prevent tooth preparation mistakes. By generating the standard electronic drawings of the framework design, the system can reduce the inconvenience caused by manual drawing, thereby facilitating dentist-technician communication and reducing the rate of remade.

Adaptación de pilares rectos sobre implantes con conexión hexagonal interna y externa por microscopía electrónica de barrido / Adaptation of straight pillars on implants with internal and external hexagonal connection by scanning electronic mi-croscopy / Adaptação de pilares retos em implantes com conexão hexagonal interna e externa por microscopia eletrônica de varredura

En implantología oral, ha sido motivo de investigación y constante evolución la interfase implante-pilar, princi-palmente desde el punto de vista biomecánico y biológico. Objetivo: Valorar el espacio o "gap" en la interfase implante-pilar en implantes de conexión hexagonal interna y externa por medio de microscopía electrónica de barrido (MEB). Materiales y Métodos: Estudio in vitro en 24 implantes (Bionnovation®) divididos en dos gru-pos (n=12): conexión hexagonal interna y externa. Para el experimento, se atornillaron pilares rectos con 30N de torque. A su vez 6 implantes por grupo se sometieron a 500000 ciclos de carga dinámica; posteriormente, se evaluó por MEB el espacio de la interfase implante pilar en 3 puntos de todas las muestras, las medias de los resultados de cada espécimen se respaldaron en tablas de Excel y se analizaron en el programa BioEstat 5.3. Resultados: Mediante test T para muestras independientes, con una significancia del 95%, se encontró una diferencia muy significativa luego de la aplicación de la carga dinámica en los implantes de hexágono ex-terno (p= 0.0002). En los implantes de hexágono interno también existió diferencia estadística (p= 0.03). Entre los implantes de hexágono externo e interno existieron diferencias muy significativas en la precisión del ajuste en la interfase implante pilar antes y después de la aplicación de las cargas dinámicas (p= <0.0001 y p= 0.0003 respectivamente). Conclusiones: Las cargas dinámicas aumentaron significativamente la discrepan-cia en la conexión implante-pilar de los implantes de hexágono externo e interno (p= < 0.05); adicionalmente, la distancia del "gap" fue mayor para los implantes de hexágono externo en contraste con los implantes de Hexágono Interno antes y después de la carga dinámica, siendo muy significativo (p= < 0.0003).

In oral implantology, the implant-pillar interface has been a subject of research and constant evolution, mainly from the biomechanical and biological point of view. Objective: To assess the gap in the implant-abutment interface in internal and external hexagonal connection implants by means of scanning electron microscopy (SEM). Materials and Methods: In vitro study in 24 implants (Bionnovation®) divided into two groups (n = 12): internal and external hexagonal connection. For the experiment, straight pillars with 30N of torque were screwed. In turn, 6 implants per group underwent 500,000 cycles of dynamic loading; Subsequently, the space of the pillar implant interface at 3 points of all samples was evaluated by MEB, the means of the results of each specimen were supported in Excel tables and analyzed in the BioEstat 5.3 program. Results: Using a T test for independent samples, with a significance of 95%, a very significant difference was found after the application of the dynamic load in the external hexagon implants (p = 0.0002). In the internal hexagon implants there was also a statistical difference (p = 0.03). Between the external and internal hexagon implants there were very significant differences in the accuracy of the adjustment in the abutment implant interface before and after the application of the dynamic loads (p = <0.0001 and p = 0.0003 respectively). Conclusions: Dynamic loads significantly increased the discrepancy in the implant-abutment connection of the external and internal hexa-gon implants (p = <0.05); additionally, the gap distance was greater for external hexagon implants in contrast to Internal Hexagon implants before and after dynamic loading, being very significant (p = <0.0003).

Na implantologia oral, a interface implante-pilar tem sido objeto de pesquisa e evolução constante, principal-mente do ponto de vista biomecânico e biológico. Objetivo: Avaliar o espaço ou "gap" na interface implan-te-pilar em implantes de conexão hexagonal interna e externa por meio de microscopia eletrônica de varre-dura (MEV). Materiais e Métodos: Estudo in vitro em 24 implantes (Bionnovation®) divididos em dois grupos (n = 12): conexão hexagonal interna e externa. Para o experimento, pilares retos com 30N de torque foram parafusados. Por sua vez, 6 implantes por grupo passaram por 500.000 ciclos de carregamento dinâmico; posteriormente, o espaço da interface do implante de pilar em 3 pontos de todas as amostras foi avaliado pelo MEV, as médias dos resultados de cada amostra foram suportadas em tabelas Excel e analisadas no programa BioEstat 5.3. Resultados: Usando um teste T para amostras independentes, com significância de 95%, foi encontrada uma diferença muito significativa após a aplicação da carga dinâmica nos implantes hexagonais externos (p = 0,0002). Nos implantes hexagonais internos também houve diferença estatística (p = 0,03). Entre os implantes hexágono externo e interno, houve diferenças muito significativas na precisão do ajuste na interface do implante de pilar antes e após a aplicação das cargas dinâmicas (p = <0,0001 ep = 0,0003, respectivamente). Conclusões: As cargas dinâmicas aumentaram significativamente a discrepância na conexão implante-pilar dos implantes hexágono externo e interno (p = <0,05); além disso, a distância do gap foi maior para os implantes hexagonais externos, em contraste com os implantes de hexágono interno antes e após o carregamento dinâmico, sendo muito significativa (p = <0,0003).

All-ceramic premolar guiding plate retains resin-bonded fixed partial dentures / 华西口腔医学杂志

OBJECTIVE@#This study aims to investigate the fracture resistance and short-term restorative effects of resin-bonded fixed partial dentures (RBFPDs) made from heat-pressed lithium-disilicate-based glass-ceramic (IPS e.max press) and zirconia ceramic (WIELAND) and retained by all-ceramic guiding plates when used to restore missing mandibular second premolars.@*METHODS@#A total of 64 human mandibular first premolars and first molars were prepared as abutments, then were randomly divided into 4 groups (n=8): E0, heat-pressed ceramic RBFPDs, no cyclic loading; E1, heat-pressed ceramic RBFPDs exposed to 300 000 cycles of dynamic loading; W0, zirconia ceramic RBFPDs, no cyclic loading; and W1, zirconia ceramic RBFPDs exposed to 300 000 cycles of dynamic loading. Fracture strength was tested in a universal testing machine.@*RESULTS@#The medians of fracture strength were 1 242.85 N±260.11 N (E0), 1 650.85 N±206.77 N (W0), 1 062.60 N±179.98 N (E1), and 1 167.61 N±265.50 N (W1). Statistical analysis showed that all the groups exhibited significantly higher fracture strength compared with the maximum bite force in the premolar region (360 N; P0.05). Significant statistical differences were found between the zirconia ceramic groups (W0 and W1, P0.05) after dynamic loading.@*CONCLUSIONS@#The RBFPDs retained by all-ceramic guiding plates exhibited promising fracture properties and optimal short-term restorative effects when used to restore missing mandibular second premolars.

Vertical and horizontal misfit analysis of 3-unit fdp fabricated with different techniques and cad/cam systems

Abstract The aim of this is was evaluate the vertical and horizontal marginal adaptation of 3-unit fixed partial denture frameworks fabricated using different techniques and CAD/CAM systems. A total of 40 framework specimens were fabricated and divided into four groups as follows: lost-wax casting (G1); lost-wax casting with welding (G2); extraoral optical scanning of models (3S/DWOS) (G3); intraoral optical scanning (Cerec Bluecam/Sirona) (G4). A reference model was used to simulate a fixed partial denture with three elements (with a central pontic). The frameworks of G1 and G2 were cast in nickel-chromium (NiCr) alloy, whereas those of G3 and G4 were milled in zirconia. In all groups, vertical and horizontal marginal adaptation (over-contour and under-contour) was evaluated using a three-dimensional optical microscope (Quick Scope, Mitutoyo). The results showed higher vertical marginal misfit in G1 than in the other groups (p<0.001). Regarding horizontal marginal misfit, higher over-contour values occurred in G3 than in the other groups (p<0.001). G3 did not show under-contour at all, whereas the other groups did not differ from each other in this regard (p>0.05). Within the limitations of this study, it can be concluded that lost-wax casting with welding is a viable alternative to the use of CAD/CAM systems to fabricate frameworks of three-unit FPDs, since the techniques yielded similar vertical misfit values. Extra-oral CAD/CAM systems showed the highest horizontal misfit (over-contour) compared to other groups.

Resumo O objetivo deste estudo foi avaliar a adaptação marginal vertical e horizontal de infraestruturas de prótese fixas de três elementos confeccionadas por diferentes técnicas e diferentes sistemas CAD/CAM. Um total de 40 infraestruturas foram confeccionadas e divididas em quatro grupos: fundição por cera perdida (G1); fundição por cera perdida com ponto de solda (G2); escaneamento óptico extraoral para escaneamento do modelo (3S/DWOS); escaneamento óptico intraoral (Cerec Bluecam/Sirona) (G4). Uma matriz metálica foi utilizada para simular uma prótese fixa de três elementos (com pôntico central). As infraestruturas do G1 e G2 foram fundidas em liga metálica de níquel-cromo (NiCr), enquanto que as infraestruturas de G3 e G4 foram fresadas em zircônia. Todos os grupos foram analisados quanto à adaptação marginal vertical e horizontal (sobrecontorno e subcontorno) em microscópio óptico tridimensional (Quick Scope, Mitutoyo). Os resultados apresentaram maiores valores de desadaptação marginal vertical no G1 comparados aos outros grupos (p<0,001). Em relação a desadaptação marginal horizontal, maiores valores de sobrecontorno foram observado no G3 em comparação com os demais grupos (p<0,001). Não foi observado valores de subcontorno para o G3, enquanto que os demais grupos não apresentaram diferença significante para o subcontorno (p> 0,05). Dentro das limitações do presente estudo, pode-se concluir que a técnica convencional após ponto de solda é uma alternativa viável para confecção de infraestruturas de próteses fixas de três elementos comparado ao uso de sistemas CAD/CAM, uma vez que as técnicas apresentaram valores de adaptação marginal vertical similares. Os sistemas CAD/CAM extraoral apresentou o maior desajuste horizontal (sobrecontorno) em comparação com outros grupos.

Accuracy of dental models fabricated by CAD/CAM milling method and 3D printing method

The purpose of this study was to evaluate the accuracy of a dental model fabricated using the CAD/CAM milling method and the 3D printing method. materials and method: this study was conducted in sequence of the digitization of the master model using an intraoral scanner, the manufacturing of working models (milling model, Multi-jet printing model and color-jet printing model) by using the scan data of the master model, the digitization of the working model by using a laboratory scanner, the superimposition of the digital data of the master model and working models using inspection software, and 3-dimensional analysis. ten measurements per group were done by one practitioner. one-way ANOVA and Tukey's post-hoc test were performed to compare the difference between the three groups. results: the overall difference in models caused by the manufacturing method was measured as 73.05µm±9.64µm, 84.52µm±4.78µm, and 96.05µm±5.43µm in the milling group, multi-jet printing group and color-jet printing group, respectively. the difference according to the shape of the teeth, the abutment teeth among the three parts was recorded with the lowest values as 19.18±2.08µm, 77.10±7.48µm, and 56.63±4.58µm. conclusions: dental models manufactured by the CAD/CAM milling method presented superior accuracy over the models manufactured by the 3D printing method. therefore, the use of optimized CAD software and appropriate materials is crucial for the fabrication accuracy of dental models.

Novel Fabrication Technique for Root-supported Overdentures: A Case Report / Técnica de fabricación novedosa para sobredentaduras apoyadas en la raíz: un reporte de caso

ABSTRACT Tooth and bone preservation is essential to support dentures, especially for elderly patients. Retaining the existing teeth and roots for an overdenture postpones edentulism, and this is a convenient alternative to complete dentures and extraction of teeth. Root-supported overdentures attach to the roots with precision attachments. The fit of the attachment of both the denture and the roots or implants is very important for overdentures. The combination of the attachments increases the retention and stability of attachment-retained overdentures. This technique describes an alternative procedure to fabricate root-supported overdentures with combined locator and casted telescopic attachments.

RESUMEN La preservación de los dientes y los huesos es esencial para apoyar las dentaduras postizas, especialmente para pacientes de edad avanzada. Retener los dientes y raíces existentes para una sobredentadura aplaza el edentulismo, y constituye una alternativa conveniente para completar las dentaduras postizas y la extracción de dientes. Las sobredentaduras apoyadas en la raíz se unen a las raíces con aditamentos de precisión. El ajuste del aditamento tanto de la dentadura como de las raíces o implantes es muy importante para las sobredentaduras. La combinación de los aditamentos aumenta la retención y la estabilidad de las sobredentaduras retenidas por aditamento. Esta técnica describe un procedimiento alternativo para fabricar sobredentaduras ancladas en la raíz con un localizador combinado y aditamentos telescópicos fundidos.

Complete denture of a skeletal class III patient with occlusal scheme in consideration: A case report / 대한치과보철학회지

Occlusal disharmony is frequently observed among edentulous patients. When artificial teeth come into contact, the unfavorable displacing force may lead to the discomfort, mucosal trauma, or even neuromuscular alterations and emotional disturbances. An optimal occlusal scheme is a critical factor for successful complete dentures. For this case, an edentulous patient with significant interarch size discrepancy due to mandibular prognathism contributing to inadequate function of dentures was treated with complete dentures. The posterior cross-bite tooth setup for compensating the abnormal jaw relations provided a stable and retentive complete denture prosthesis, which was considered adequate by both patient and dentist.

Como utilizar o conceito da Zona Neutra para otimizar a Prótese / Using the Neutral Zone concept to improve the lower complete

Este artigo descreve os passos para a utilização da filosofia da Técnica da Zona Neutra. Através dessa filosofia, procura-se localizar uma área, em boca, onde as forças geradas pela língua são neutralizadas pelas forças geradas pelos lábios e bochechas, estabilizando assim a prótese.

This article describes step-by-step the application of the Neutral Zone technique philosophy. It is based upon the concept that for each individual patient, there is within the denture space a specific area where the function of the musculature will not unseat the denture and where forces generated by the tongue are neutralized by the forces generated by the lips and cheeks.

Alternativas Estéticas frente a una agenesia de incisivo lateral como parte de una rehabilitación oral integral / Alternativas estéticas a uma agenesia do incisivo lateral como parte de uma reabilitação oral integral / Aesthetic alternatives for lateral incisor agenesia as part of an integral oral rehabilitation

En la actualidad los tratamientos estéticos restauradores han adquirido una importancia fundamental dentro de los consul-torios dentales, debido a la importancia que los pacientes han dado a su sonrisa como un factor que les ayuda a mejorar su autoestima y calidad de vida. Paciente de sexo femenino de 39 años de edad, que acudió a la consulta con el deseo de mejorar su sonrisa, debido a que ya recibió un tratamiento anterior pero no se encontraba satisfecha. Al examen clínico presentó agenesia de la pieza dental 22 y en su lugar se encontró un canino con una corona de metal porcelana defectuosa, diastema entre las piezas 23 y 21, atrición de las piezas 11 y 21, discromía de la 12 y asimetría dental de los dientes anterosuperiores. El objetivo del presente caso clínico es describir un método muy riguroso de análisis dentofacial que permita llegar a un diagnóstico preciso y de esta forma establecer un Plan de Tratamiento Integral (Funcional, Biológico y Estético), transformando el canino en incisivo lateral y mejorando la sonrisa de la paciente.

Nowadays aesthetic restorative tratments have accuried a main importance in dental clinics, because of the importance that patients give to their smile as a factor that helps thems to improve their self steem and life quality. Female patient aged 39 years old, comes for consultation wishing to improve her smile, having recived a prior treatment that didnt satisfy her. Clinical examination revealed agenesia of tooth 22 and in its place a canine with a defective metal ceramic crown was found, spacing between teeth 23 and 21, atrition on teeth 11 and 21, discromia of tooth 12 and dental asimmetry of upper front teeth. The objective of this case report is to describe a rigurous dentofacial analisys which allows to obtain a precisse diagnosis and stablish a integral treatment plan (Funtional, Biological and Aesthetical) transforming the canine to lateral incisor and im-proving the patients smile.

Atualmente, os tratamentos estéticos restaurativos têm adquirido uma importância fundamental nas consultas odontológi-cas, devido à importância que os pacientes deram ao seu sorriso como um fator que os ajuda a melhorar sua auto-estima e qualidade de vida.Uma paciente do sexo feminino de 39 anos que foi à consulta odontológica com o desejo de melhorar o sorriso dela, devi-do que já havia recebido tratamento prévio, mas não estava satisfeita. No exame clínico, ela apresentou uma agenesia do dente 22 e no espaço dele encontrou-se um canino com uma coroa de metal porcelana defeituosa, diastema entre os dentes 23 e 21, desgaste dos dentes 11 e 21, mudança de cor do 12 e assimetria dentária dos dentes supero-anteriores. O objetivo deste reporte de caso clínico é descrever um método muito rigoroso de análise dentofacial que nos permita chegar a um diagnóstico preciso e assim estabelecer um Plano de Tratamento Integral (Funcional, Biológico e Estético), transformando o canino em um incisivo lateral, melhorando o sorriso da paciente.

Prótese total imediata ­ do planejamento à instalação / Complete immediate denture ­ planning and performing

A confecção de uma Prótese Total Imediata é um procedimento complexo para os profissionais e estressante para o paciente. O presente artigo descreve a sequência clínica do planejamento à realização deste procedimento, com segurança e previsibilidade.

The fabrication of an Immediate Complete Denture is a complex procedure for the practitioners involved and a stressing situation for the patient. This article describes the clinical sequence for planning and performing this procedure with safety and predictability.