Bioseguridad en el laboratorio dental / Biosafety in the dental laboratory

Una enfermedad infecciosa es aquella producida por un agente infeccioso (bacterias, hongos, virus, etc.) que ingresa y se desarrolla en el organismo de un hospedero. Posteriormente, puede trasmitirse de un individuo a otro directamente por contacto entre ambos, o bien, indirectamente, por medio de un vec-tor biológico (de naturaleza animal o vegetal), o de un fómite (objeto inanimado). Las vías por las que un agente infeccioso puede ingresar a un hospedero son: inhalación (respiración de aerosoles), ingestión (salpicaduras de gotas), penetración de mucosas (na-sal, ocular y bucal) o lesiones en la piel o mucosas. Las fuentes de infección pueden ser los pacientes, el personal del consultorio o laboratorio, las superficies e instrumental contaminados y las prótesis o com-ponentes de éstas. Para evitar la propagación de los agentes microbianos se debe interrumpir el proceso de transmisión de los mismos. Todo profesional debe fortalecer y readecuar normas y protocolos de biose-guridad en la tarea diaria, para minimizar el riesgo de transmisión directa y cruzada entre el profesional, su equipo auxiliar, el laboratorista y los pacientes (AU)

An infectious disease is one caused by an infectious agent (bacteria, fungi, virus, etc.) that enters and develops in a host. Then it can be transmitted from one individual to another directly by contact between the two or, indirectly through a biological vector (an animal or plant nature), or a fomite (an inanimate object). The routes by which an infectious agent can enter a host are: inhalation (breathing of aerosols), ingestion (splash of droplets), penetration of mucous membranes (nasal, ocular and oral) and skin or mucous lesions. Sources of infection can be patients, office or laboratory personnel, contaminated surfaces and instruments and the prosthesis or component thereof. To prevent the spread of microbial agents, the process of their transmission must be interrupted. Every professional must strengthen and readjust biosafety standards and protocols in daily work to minimize the risk of direct and cross-transmission between the professional, his auxiliary team, the laboratory technician and the patients (AU)

Presencia de bacterias en prótesis dentales durante el proceso de elaboración / Presence of bacteria in dental prostheses during the elaboration process

Existe una creciente preocupación sobre el tema de la infección cruzada en clínicas y laboratorios dentales. El laboratorio odontológico debe seguir normas de bioseguridad que garanticen a todo el equipo de salud la prevención de estas infecciones. Los técnicos que allí laboran corren el riesgo de exponer su cara a salpicaduras, así como a rocíos de sangre y saliva. Este estudio fue diseñado para saber si los laboratorios a los que recurrimos cumplen con estas normas de bioseguridad, y qué tan confiados podemos estar de la desinfección por parte de ellos, ya que las prótesis deberían estar desinfectadas correctamente antes de colocarlas en boca (AU)

There is growing concern about the issue of cross infection in dental clinics and laboratories. The dental laboratory must follow biosafety standards that guarantee the prevention of these infections to the entire health team. The technicians who work there run the risk of exposing their face to splashes and spray of blood and saliva. This study was designed to find out if the laboratories we use comply with these biosafety standards, and how confident we can be of their disinfection by them, since the prostheses should be properly disinfected before placing them in the mouth (AU)

Laboratorio mecánico dental: norma técnica No. 24-2019 / Dental mechanical laboratory: technical standard No. 24-2019

Este documento tiene como objeto: "la regulación, autorización y control de los laboratorios mecánicos dentales, en concordancia con el Reglamento para la Regulación, Autorización, Acreditación y Control de Establecimientos de Atención para la Salud, Acuerdo Gubernativo 376-2007." Es de carácter obligatorio, por lo que se aplica tanto al sector público, privado, social o subsector de la seguridad social, en todo el territorio nacional. Contiene además, las definiciones de los conceptos relacionados al tema principal, además de la infraestructura que deberá tener cada clínica, incluidos el equipo y recurso humano y técnico.

Endocrown restorations for extensively damaged posterior teeth: clinical performance of three cases

The restoration of endodontically treated teeth (ETT) with more than one cusp missing and thin remaining walls is challenging for the general practitioner. The use of posts combined with full coverage restorations is a well-established approach, yet not following the minimal invasive principles of adhesive dentistry. Endocrowns are indirect monoblock restorations that use the pulp chamber of the ETT for retention. In this study the fabrication of 4 endocrowns and their clinical performance will be discussed. Two clinical cases include computer-aided design/computer-aided manufacturing manufactured molar endocrowns (one feldspathic ceramic and one hybrid composite-ceramic restoration) and the other two are dental laboratory manufactured resin composite premolar endocrown restorations. The modified United States Public Health Service criteria were used to assess the clinical behavior of the restorations at different follow up periods. Endocrown restorations present a satisfactory clinical alternative, either by the use of resin composite or glass ceramic and hybrid materials. Specific guidelines with minimal alterations should be followed for an endocrown restoration to be successful. Due to limited evidence regarding the long term evaluation of this restorative technique, a careful selection of cases should be applied.

Survival rate of modern all-ceramic FPDs during an observation period from 2011 to 2016

PURPOSE: In literature, many studies compare survival rates of different types of FPDs. Most of them compared restorations, which originated from one university, but from different clinicians. Data about restoration survival rates by only one experienced dentist are very rare. The aim of this study was to evaluate the survival rate of allceramic FPDs without the blurring effects of different clinicians. MATERIALS AND METHODS: 153 veneeredzirconia FPDs were observed for follow-up. 22 patients received 131 single crowns and 22 bridges. Because of the different bridge lengths, one unit was defined as a restored or replaced tooth. In total, 201 units were included. Only the restorations performed by the same clinician and produced in the same dental laboratory from 2011 to 2016 were included. Considered factors were defined as “type of unit”, “type of abutment”, “intraoral region”, and “vitality”. Modified UHPHS criteria were used for evaluation. Statistical analysis was performed using cox-regression. RESULTS: 189 units (94.0%) showed no kind of failure. 5 chippings (2.4%) could be corrected by intraoral polishing. 4 units (1.9%) exhibited spontaneous decementation. These polishable and recementable restorations are still in clinical use. Chippings or decementations, which lead to total failure, did not occur. One unit was completely fractured (0.5 %). Biological failures (caries, periodontitis or periimplantitis) did not occur. The statistical analysis of the factors did not reveal any significant differences. CONCLUSION: Modern all-ceramic FPDs seem to be an appropriate therapy not only for single restorations but for complex occlusal rehabilitations.

Avances en la planificación de casos tratados con ortodoncia y cirugía ortognática. Parte 2 / Advances in planning the cases treated with orthodontics and orthognathic surgery. Part 2

En estos artículos los autores presentan una nueva línea de instrumentos de precisión usados en el procedimiento de laboratorio para la preparación de modelos set-up, corrección de modelos set-up y cirugía de modelos de acuerdo con el plan de tratamiento ortodóncico y quirúrgico. Se describen en este artículo el Set-Up Model Maker (SUM), el Occlusal Plane Reference (OPR) y el Surgical Model Accuracy Device (SMAD), y se explica su utilización a través del tratamiento de un caso clínico con clase III esquelética y mordida abierta...

In these articles the authors introduce a new line of precision instruments used in the laboratory procedure for set-up models preparation, set-up models correction and model surgery according to the orthodontic and surgery treatment plan. The Set-Up Model Maker (SUM), the Occlusal Plane Reference (OPR) and the Surgical Model Accuracy Device (SMAD) are described in this article, and its use is explained through the case report of a treatment of a skeletal class III case with open bite...

The path of placement of a removable partial denture: a microscope based approach to survey and design

This article reviews the topic of how to identify and develop a removable partial denture (RPD) path of placement, and provides a literature review of the concept of the RPD path of placement, also known as the path of insertion. An optimal RPD path of placement, guided by mutually parallel guide planes, ensures that the RPD flanges fit intimately over edentulous ridge structures and that the framework fits intimately with guide plane surfaces, which prevents food collecting empty spaces between the intaglio surface of the framework and intraoral surfaces, and ensures that RPD clasps engage adequate numbers of tooth undercuts to ensure RPD retention. The article covers topics such as the causes of obstructions to RPD intra-oral seating, the causes of food collecting empty spaces that may exist around an RPD, and how to identify if a guide plane is parallel with the projected RPD path of placement. The article presents a method of using a surgical operating microscope, or high magnification (6-8x or greater) binocular surgical loupes telescopes, combined with co-axial illumination, to identify a preliminary path of placement for an arch. This preliminary path of placement concept may help to guide a dentist or a dental laboratory technician when surveying a master cast of the arch to develop an RPD path of placement, or in verifying that intra-oral contouring has aligned teeth surfaces optimally with the RPD path of placement. In dentistry, a well-fitting RPD reduces long-term periodontal or structural damage to abutment teeth.

Evaluation of fitness in implant screw as tightening torque in dental laboratory

PURPOSE: The purpose of this study was to measure the tightening torque for dental implant in dental laboratory and to analyze of the effects of different tightening torque. MATERIALS AND METHODS: The tightening torque for dental implant in dental laboratory were measured by digital torque gauge. The length of abutment and analog were measured as tightening torque of manufacturer's instructions and the measured value. And the data were statically analyzed. RESULTS: The mean tightening torque of implant screw in dental laboratory was 1.563 +/- 0.332 Ncm. The external type implant system of total length were showing no significant differences but the internal type implant system had difference significant (P < 0.05) when compared with tightening torque. CONCLUSION: The implant prosthesis should be made under manufacturer's instructions especially as tightening torque of screw. For the fidelity of implant prosthesis, dental technician should learn how to use the torque gauge.

A laboratory assessment of bacterial leakage in MTA apical plugs exposed to phosphate-buffered saline / Avaliação laboratorial da infiltração bacteriana em plugs apicais de mta expostos ao tampão fosfato-salino

O presente estudo avaliou a influência da exposição do agregado de trióxido mineral (MTA) – com e sem cloreto decálcio (CaCl2) – ao tampão fosfato-salino (PBS) sobre a microinfiltração apical. Sessenta segmentos radiculares foram divididos em 4 grupos experimentais (n=15). As cavidades apicais foram preenchidas com MTA, com ou sem CaCl2, e os canais radiculares receberam uma bolinha de algodão umedecida ou PBS, como medicação intracanal: 1) MTA/bolinha de algodão umedecida; 2) MTA/PBS; 3) MTA+10%CaCl2/ bolinha de algodão umedecida; 4) MTA+10% CaCl2/PBS. Após 2 meses, a penetração de E. faecalis ao longo dos plugs apicais foi avaliada. As amostras foram observadas semanal -mente durante 70 dias e a infiltração detectada através da turbidez do meio em contato com os segmentos radiculares. Dentes pertencentes aos grupos controle (n=2) foram mantidos completamente impermeáveis ou sem plug apical. A análise de sobrevivência e a comparação das curvas foram realizadas por meio dos testes Kaplan-Meier e Log-rank (p<0.05), respectiva -mente. Todas as amostras do grupo controle positivo apresentaram evidência de infiltração dentro de 24h, enquanto nenhuma amostra do grupo controle negativo apresentou infiltração aolongo dos 70 dias. Não houve diferença significativa entre os grupos experimentais (p=0.102). O uso do PBS como medicação intracanal pode melhorar a capacidade de selamento do MTA,mas não é capaz de impedir a infiltração bacteriana. A adição de CaCl2 ao MTA não melhora sua capacidade de selamento.

This study evaluated the influence of the exposure of mineral trioxide aggregate (MTA) - with and without calcium chloride(CaCl2) -to phosphate-buffered saline (PBS) on apical microleakage. Sixty root segments were divided into 4 experimental groups (n=15). Apical cavities were filled with MTA with or without CaCl2, and the root canals dressed with a moistened cotton pellet or PBS: 1) MTA/cotton pellet; 2) MTA/PBS; 3) MTA+10%CaCl2/cotton pellet; 4) MTA+10%CaCl2/PBS. After 2months, E. faecalis penetration was analyzed a long the apical plugs. Samples were observed weekly for 70 days, and leakage was detected by turbidity of the medium in contact with the root segment. Teeth in the control groups (n=2) were either made completely impermeable or kept without an apical plug. The Kaplan–Meier method was used to analyze survival and the Log-rank test was used to compare the survival curves (p<0.05). All specimens in the positive control group showed evidence of leakage within 24h, while none in the negative control group showed leakage up to 70 days. There was no statisticall y significant difference among the experimental groups (p=0.102).The use of PBS as intracanal dressing may improve MTA sealing ability, but cannot prevent bacterial leakage. The addition of CaCl2 to the MTA did not improve MTA sealing ability.

Communication between dental office and dental laboratory: from paper-based to web-based

Proper communication between dental office and dental laboratory leads to well-designed prosthesis, satisfied clinician, and comfortable professional relationship between clinician and dental technician. The communication occurs usually through a laboratory work authorization Form containing handwritten instructions from the clinician to the dental technician, that specify the materials to be used and the type of the prosthesis. This paper-based recording has several major drawbacks such as mis-communication between the laboratory and the clinic and lack of visual interactivity. This article discusses the current web-based application for dental office-laboratory communication, and explains system design and requirement for Web Content Management System [WCMS] that can be used for communication between dental clinic and dental laboratory. Recent improvement in internet connection, uploading and downloading data facilitates transferring data between dental office and dental laboratory. Market is now crowded with desktop applications that help to manage laboratory cases and improve online communication between dental clinic and dental laboratory. Dental office-laboratory management systems are available as a commercial WCMS and open-source WCMS. Commercial system is commonly used because it is designed and modified according to user's requirements. In addition, it is a user-friendly interface and more secure when handling payments

Buscando precisión en el montaje en articulador / Looking for precision in articulator mounting

Se presenta una técnica de montaje de precisión, de fácil ejecución y al alcance del odontólogo y del técnico de laboratorio, destinada a brindar un mejor resultado clínico de los procedimientos restauradores, tanto protéticos como ortodóncicos

We present a technique for precision assembly, easy to perform and reach for the dentist and lab technician, aimed at providing a better clinical outcome of both prosthetic and orthodontics restorative procedures.

Comparative study on direct and indirect bracket bonding techniques regarding time length and bracket detachment

OBJECTIVE: The aim of this study was to assess the time spent for direct (DBB - direct bracket bonding) and indirect (IBB - indirect bracket bonding) bracket bonding techniques. The time length of laboratorial (IBB) and clinical steps (DBB and IBB) as well as the prevalence of loose bracket after a 24-week follow-up were evaluated. METHODS: Seventeen patients (7 men and 10 women) with a mean age of 21 years, requiring orthodontic treatment were selected for this study. A total of 304 brackets were used (151 DBB and 153 IBB). The same bracket type and bonding material were used in both groups. Data were submitted to statistical analysis by Wilcoxon non-parametric test at 5% level of significance. RESULTS: Considering the total time length, the IBB technique was more time-consuming than the DBB (p < 0.001). However, considering only the clinical phase, the IBB took less time than the DBB (p < 0.001). There was no significant difference (p = 0.910) for the time spent during laboratorial positioning of the brackets and clinical session for IBB in comparison to the clinical procedure for DBB. Additionally, no difference was found as for the prevalence of loose bracket between both groups. CONCLUSION: the IBB can be suggested as a valid clinical procedure since the clinical session was faster and the total time spent for laboratorial positioning of the brackets and clinical procedure was similar to that of DBB. In addition, both approaches resulted in similar frequency of loose bracket.

OBJETIVO: avaliar o tempo necessário para realização da colagem de braquetes pelas técnicas direta (CDB) e indireta (CIB), mensurando o tempo despendido entre a parte laboratorial (CIB) e a parte clínica (CDB e CIB), e a prevalência de descolamentos durante o período de observação de 24 semanas. MÉTODOS: dezessete pacientes (7 homens e 10 mulheres), com idade média de 21 anos, com necessidade de tratamento ortodôntico, foram selecionados para participar desse estudo. Foram utilizados um total de 304 braquetes, sendo que 151 foram colados pela técnica de CDB e 153 pela CIB, com o mesmo tipo de braquete e material de colagem. Os dados foram submetidos ao teste não paramétrico de Wilcoxon, com significância de 5%. RESULTADOS: o tempo total para realização da CIB foi maior em relação à CDB (p < 0,001). Levando em consideração apenas a fase clínica, foi observado que o tempo para CIB foi menor em relação a CDB (p < 0,001). A comparação entre o tempo despendido para o posicionamento dos braquetes em laboratório mais o tempo em clínica para CIB com o tempo em clínica para a CDB revelou que não houve diferença significativa (p = 0,910), nem tampouco quanto à prevalência de descolamento dos braquetes. CONCLUSÃO: a CIB apresenta-se como uma utilidade clínica singular, pois o tempo em clínica foi menor que o da CDB. O tempo despendido no posicionamento dos braquetes no laboratório e de execução clínica da CIB foi semelhante ao tempo gasto pela CDB, a quantidade de descolamentos foi semelhante entre as técnicas.

Procedimentos laboratoriais na confecção de prótese sobre implante utilizando o sistema tubo-parafuso / Laboratory procedures on the manufacture of implant-supported prostprosthesis using the tube-screw system

A utilização dos implantes osseointegrados teve um progresso significativo nos últimos 30 anos, promovendo um grande impulso da Implantodontia na área odontológica. No entanto, com a crescente utilização desses implantes, começaram a surgir problemas relacionados com a estética e mecânica dos componentes protéticos, principalmente em reabilitações extensas, nas quais a posição dos implantes não permite a realização de próteses parafusadas. Passou-se, então, a buscar uma solução para corrigir o posicionamento destes implantes sem que a reversibilidade do tratamento fosse perdida, já que as próteses cimentadas não possuem essa característica. O sistema tubo-parafuso ou de parafusamento lateral é uma excelente opção para solucionar os casos de implantes mal posicionados, visto que conciliam as vantagens estéticas e mecânicas das próteses cimentadas com a reversibilidade e manutenção das próteses parafusadas, permitindo satisfazer as expectativas do paciente e do profissional. Assim, no intuito de facilitar a execução e disseminação da técnica, o presente trabalho tem por objetivo mostrar o passo a passo laboratorial para a confecção de uma prótese sobre um implante mal posicionado, utilizando o sistema tubo-parafuso da empresa Odontofix®.

The use of osseointegrated implants had a significant development in the last 30 years, providing a new direction for implantology. However, as the use of these implants increased some esthetic and mechanical problems have been observed, especially in extensive works where the position of those implants did not allow screw retained prostheses. Therefore, it was started a search for ways to correct the positioning of these implants without compromising the reversibility of the treatment, which is not a characteristic of cemented prosthesis. The tube-screw technique or lateral fixation screw is an excellent option to solve clinical cases of poorly placed implants, because merge the advantages of aesthetic and mechanical cemented prosthesis with the reversibility and maintenance of the screwed prosthesis, allowing to satisfy the expectations of the patient and the professional. Therefore, to facilitate the implementation and dissemination of the technique, the aim of the present study was to demonstrate the laboratorial step-by-step for the manufacture of a prosthesis over misplaced implant, using the tube-screw system of Odontofix®.

Ligas metálicas empregadas na confecção de retentores intrarradiculares nas Cidades de João Pessoa e Campina Grande–PB / Alloys employed in the manufacture of seals intraradical cities in Joao Pessoa and Campina Grande-PB

Objetivo: Identificar os tipos de ligas metálicas que sãoutilizadas na fundição de retentores intrarradiculares em 20laboratórios de prótese dentária nas cidades de João Pessoae Campina Grande. Material e Métodos: Dois examinadorescalibrados preencheram um formulário contendo as seguintesinformações em uma amostra de 400 retentores: 1)Localização do retentor na arcada dentária, liga metálicaempregada, nome comercial e se o dentista indicava a liga aser empregada na fundição. Resultados: Em João Pessoa,45,71% dos retentores foram confeccionados para dentesanteriores e (54,29%) para os posteriores (54,29%); emCampina Grande, 47,50% eram anteriores e 52,55%posteriores. As ligas mais utilizadas em João Pessoa foram abase de níquel-cromo (87,5%) e de cobre-zinco-alumínio(6,5%). Em Campina Grande, as de níquel-cromo (50%) ecobre-zinco-alumínio (50%). Conclusões: Na cidade de JoãoPessoa, as ligas metálicas mais empregadas foram à basede níquel-cromo; na cidade de Campina Grande foram à basede cobre-alumínio e níquel-cromo; na maioria das vezes, aseleção da liga metálica tem sido uma decisão do técnico deprótese dentária.

Objective: To identify the types of metal alloys used in thecasting of intraradicular retainers in 20 prosthesis laboratoriesin the cities of João Pessoa and Campina Grande. Materialand methods: Two calibrated examiners completed a formcontaining the following information about 400 retainers:location of the retainer in the dental arch, metal alloy used,trade name and presence or not of a statement by the dentistindicating the alloy to be used in the casting. Results: In JoãoPessoa, 45.71% of the intraradicular retainers were madefor anterior and 54.29% for posterior teeth; in CampinaGrande, 47.50% were for anterior and 52.55% for posteriorteeth. Most of the alloys used in João Pessoa were based onnickel-chromium (87.5%) and copper-zinc-aluminum (6.5%)materials. In Campina Grande, there was predominance ofnickel-chromium (50%) and copper-zinc-aluminum (50%).Conclusions: In João Pessoa, most of metal alloys used werebased on nickel-chromium material, whereas in the city ofCampina Grande there was predominance of copperaluminumand nickel-chromium; in most cases, the selectionof the alloy was a decision made by the prosthesis technician.

Perfil das reabilitações sobreimplantes confeccionadas no ceará / Profile of implant rehabilitations made in Ceará (Brazil)

Esse estudo avaliou o perfil das reabilitações protéticas sobreimplantes osseointegrados confeccionadas no Estado do Ceará (Brasil), a partir da observação dos trabalhos protéticos enviados aos laboratórios de prótese. Foi aplicado um questionário aos técnicos em prótese dentária (TPD) inscritos no Conselho Regional de Odontologia – Ceará. Os principais resultados mostraram que: a) o articulador semiajustável não era usado rotineiramente pela maioria dos cirurgiões-dentistas (70,3%); b) o implante de hexágono externo (78,4%) e os componentes Ucla calcináveis (50%) compreenderam as maiores indicações clínicas; c) as maiores falhas técnicas foram erros na posição tridimensional do implante (45,2%) e na transferência ou moldagem dos implantes (41,9%). Verificou-se que o perfil das reabilitações sobreimplantes era bastante tradicional e baseado em algumas seleções inapropriadas de materiais e técnicas. Concluiu-se a importância de uma constante atualização técnica e científica, bem como maior integração entre os profissionais da área (implantodontista, protesista e técnico), no intuito de oferecer melhores reabilitações protéticas aos pacientes.

This study evaluated the profile of implant-retained dental prosthesis made in the State of Ceará (Brazil), from the observation of the works sent to the dental laboratories. A questionnaire was given to dental technicians (TPD) registered in the Regional Council of Dentistry – Ceará. The main results showed that: 1) the semi-adjustable articulator was not routinely used by most dentists (70.3%); 2) the implant external hexagon (78.4%) and cast Ucla abutments (50%) comprised the major clinical indications; 3) the main technical failures were errors in three-dimensional position of the implant (45.2%) and implant transfer impressions (41.9%). It was verified that the profile of oral rehabilitation was quite traditional and based on some inappropriate selections of materials and techniques (for example: cast Ucla). It was concluded the importance of constantly technical and scientific updating as well as greater integration among the professionals (surgeon, prosthodontist, and dental technician) in order to provide better prosthetic rehabilitation for patients.

Effect of alginate chemical disinfection on bacterial count over gypsum cast

PURPOSE: To evaluate the efficacy of sodium hypochlorite (1 : 10) and iodophor disinfectants on alginate impressions along with their effect on the survived bacterium count on the gypsum cast. MATERIALS AND METHODS: Four alginate impression on each dentate patients were made, of which Group I were not washed or disinfected, Group II impressions were merely washed with water, Group III were disinfected by spraying with sodium hypochlorite (1 : 10), Group IV were disinfected with iodophor (1 : 213). Gypsum cast (type III) were made from all the impression. Impressions and gypsum cast were swabbed in mid palatal region for bacterial culture. Bacterial colony counting done after 3 days of incubation at 37degrees C in blood agar media. The data obtained was analyzed by one way ANOVA test at a significant difference level of 0.05. RESULTS: Group I and Group II showed significantly more bacteria compared to Group III and Group IV. Bacterial colonies on the alginate impression and gypsum cast in group disinfected with Sodium hypochlorite (1 : 10) were 0.18, 0.82 respectively compared to group treated with iodophor (1 : 213). There was an increase in bacterial count on dental cast compared to source alginate impressions. CONCLUSION: Sodium hypochlorite (1 : 10) was found to be better disinfectant for alginate impression. There was an indication of increase in number of bacteria from alginate impression to making of dental cast. Additional gypsum cast disinfectant procedures need to be encouraged to completely eliminate cross infection to dental laboratory.

Provisórios anteriores maquiados e estratificados / Anteriors temporary maquiated and stratified

Para corresponder tecnicamente ao crescente apelo estético de nossos pacientes, obtendo resultados consistentes, é fundamental que sejamos previsíveis. A maneira de atingirmos essa previsibilidade passa pela padronização dos porcedimentos. Através do enceramento diagnóstico e subsequente preparação de provisórios, conseguimso testar nossa propostas de tratamento e perceber seus acertos e falhas, permitindo a participação ativa de nosso paciente. Com essas informações, aq posterior aplicação cerâmica fica grandemente simplificada, bastando ao técnico reproduzir o que já foi acordado entre o cirurgião-dentista e o paciente.

To technically meet the growing aesthetic appeal of our patients, and to obtain consistent results, it is essential for us to be predictable. The way to achieve this predictability is the standardization of procedures. Through the diagnostic waxing and subsequent preparation of temporaries, we test the proposed treatment and realize its successes and failures, allowing the active participation of our patient. With this information, the subsequent application of the ceramic is greatly simplified, and the technician simply reproduces what has already been agreed between dentist and patient.

Standards of teeth preparations for anterior resin bonded all-ceramic crowns in private dental practice in Jordan

OBJECTIVES: To investigate if general dental practitioners (GDPs) in private practice in Jordan follow universal guidelines for preparation of anterior teeth for resin bonded all-ceramic crowns (RBCs). MATERIAL AND METHODS: A sample (n=100) of laboratory models containing 208 tooth preparations for IPS Empress and In Ceram, featuring work from different GDPs, was obtained from 8 commercial dental laboratories. Aspects of preparations were quantified and compared with accepted criteria defined following a review of the literature and recommendations of the manufactures' guidelines. RESULTS: Subgingival margins on the buccal aspect were noticed in 36 percent of the preparations, 54 percent demonstrated overpreparation with a tendency to overprepare the teeth on the mesiodistal plane more than buccolingual plane. Twenty percent of samples presented a shoulder finish line while a chamfer margin design was noticed in 39 percent. Twenty-nine percent and 12 percent of samples had either a feathered or no clear margin design respectively. Incisal underpreparation was observed in 18 percent of dies of each type. Only 17 percent of all preparations were found to follow the recommended anatomical labial preparations while 29 percent of the RBC preparations were found to have the recommended axial convergence angle. In total, 43 percent of preparations were found to have the recommended depth of the finish line. CONCLUSIONS: It was found that relevant guidelines for RBC preparations were not being fully adhered to in private practice in Jordan.

New virtual orthodontic treatment system for indirect bonding using the stereolithographic technique / 대한치과교정학회지

The purpose of this article is to introduce a new virtual orthodontic treatment (VOT) system, which can be used to construct three-dimensional (3D) virtual models, establish a 3D virtual setup, enable the placement of the virtual brackets at the predetermined position, and fabricate the transfer jig with a customized bracket base for indirect bonding (IDB) using the stereolithographic technique. A 26-year-old woman presented with anterior openbite, crowding in the upper and lower arches, and narrow and tapered upper arch, despite having an acceptable profile and balanced facial proportion. The treatment plan was rapid palatal expansion (RPE) without extraction. After 10 days of RPE, sufficient space was obtained for decrowding. After a 10-week retention period, accurate pretreatment plaster models were obtained using silicone rubber impression. IDB was performed according to the protocol of the VOT system. Crowding of the upper and lower arches was effectively resolved, and anterior openbite was corrected to normal overbite. Superimposition of the 3D virtual setup models (3D-VSM) and post-treatment 3D virtual models showed that the latter deviated only slightly from the former. Thus, the use of the VOT system helped obtain an acceptable outcome in this case of mild crowding treated without extraction. More cases should be treated using this system, and the pre- and post-treatment virtual models should be compared to obtain feedback regarding the procedure; this will support doctors and dental laboratory technicians during the learning curve.