Sobrevivência em fadiga de coroas bioinspiradas bilaminadas: estudo in vitro / Fatigue survival rate of bioinspired bilaminar crowns: in vitro study

O objetivo deste estudo foi avaliar o comportamento biomecânico através da resistência à fadiga e análise por elementos finitos de coroas bioinspiradas bilaminadas com infraestruturas modificadas na superfície vestibular (Estudo A) e utilizando diferentes materiais cerâmicos com módulos elásticos distintos (Estudo B). Para isso, foram confeccionados 90 preparos para coroa total em resina epóxi G10, sobre os quais foram preparadas coroas bioinspiradas de acordo com os seguintes grupos: Estudo A - IC (infraestrutura convencional), IME (infraestrutura modificada estratificada) e IMC (infraestrutura modificada cimentada), todas confeccionadas em dissilicato de lítio (infraestrutura) + porcelana (recobrimento); Estudo B ­ DL+LEU (dissilicato de lítio + leucita), LEU+DL (leucita + dissilicato de lítio), CH+DL (cerâmica híbrida + dissilicato de lítio) e CH+LEU (cerâmica híbrida + leucita). Para o Estudo A, todas as infraestruturas foram usinadas; os recobrimentos dos grupos IC e IME foram confeccionados através da estratificação, e os recobrimentos do grupo IMC foram usinados. Já para o Estudo B, todas as peças foram usinadas, de acordo com o material cerâmico de cada grupo. Em seguida, foi realizada a cimentação adesiva dos recobrimentos sobre as infraestruturas (a depender do grupo) e das coroas sobre os preparos utilizando cimento resinoso fotopolimerizável (Variolink Esthetic LC). Após a cimentação, os espécimes foram submetidos ao teste de fadiga cíclica (10.000 ciclos, 20Hz), e como desfecho foram considerados dois eventos, em que o primeiro foi a ocorrência de trinca e/ou lascamento (evento 1) e o segundo foi a falha catastrófica do conjunto (evento 2). Os valores de carga e número de ciclos para falha em que foram observados os eventos 1 e 2 foram utilizados para realizar a análise de sobrevivência de acordo com Kaplan-Meier e Log-Rank (Mantel-Cox; 95%). As marcas de fratura e o modo de falha das coroas foram avaliados e classificados por estereomicroscópio óptico e microscópio eletrônico de varredura. Por fim, foi realizada análise por elementos finitos (FEA) para ambos os estudos, a fim de avaliar a distribuição de tensões sobre as coroas e interface adesiva. Para o Estudo A, os resultados do teste de fadiga mostraram que, considerando o evento 1 (trinca/lascamento), os grupos IC e IMC apresentaram médias de carga fadiga estatisticamente significantes entre si (733,33 N e 913,33 N, respectivamente), enquanto o grupo IME apresentou média superior (1.020 N). O mesmo foi observado para o número de ciclos em fadiga para todos os grupos. Ao considerar o evento 2 (falha catastrófica), os três grupos apresentaram médias estatisticamente semelhantes entre si (~1.028 N). Os resultados de FEA mostraram que o grupo IC concentrou maior tensão de tração do que os grupos IME e IMC. Para o Estudo B, no teste de fadiga, o grupo DL+LEU apresentou a maior média de resistência à fadiga (evento 1: 913,33 N e evento 2: 1033,33 N), enquanto todas as outras combinações de materiais cerâmicos analisadas foram estatisticamente semelhantes entre si, considerando carga e número de ciclos. Com relação ao FEA, os grupos com cerâmica híbrida (CH+DL e CH+LEU) apresentaram menores picos de concentração de tensão na infraestrutura do que os grupos com cerâmicas vítreas (DL+LEU e LEU+DL), porém, em contrapartida, concentraram maior tensão na interface adesiva. Com isso, conclui-se que a utilização da infraestrutura modificada é uma alternativa viável e promissora para tratamentos reabilitadores, apresentando sobrevivência em fadiga e distribuição de tensões satisfatórias. Além disso, a combinação entre uma infraestrutura de dissilicato de lítio e recobrimento de cerâmica a base de leucita corresponde a melhor abordagem considerando a infraestrutura modificada.(AU)

The objective of this study was to evaluate the biomechanical behavior through fatigue resistance and finite element analysis of bilaminar bioinspired crowns with modified infrastructures on the buccal surface (Study A) and using different ceramic materials with different elastic moduli (Study B). For this, 90 preparations were made for a full crown in G10 epoxy resin, on which bioinspired crowns were prepared according to the following groups: Study A - CI (conventional infrastructure), SMI (stratified modified infrastructure) and CMI (cemented modified infrastructure ), all made of lithium disilicate (infrastructure) + porcelain (veneer); Study B ­ LD+LEU (lithium disilicate + leucite), LEU+LD (leucite + lithium disilicate), HC+LD (hybrid ceramic + lithium disilicate) and HC+LEU (hybrid ceramic + leucite). For Study A, all infrastructures were machined; the coverings of the CI and SMI groups were made through stratification technique, and the veneers of the SMI group were machined. For Study B, all pieces were machined, according to the ceramic material of each group. Then, the veneers were cemented into their infrastructures (depending on the group) and crowns were cemented into preparations using light-cured resin cement (Variolink Esthetic LC). After cementing, the specimens were subjected to the cyclic fatigue test (10,000 cycles, 20Hz), and as an outcome two events were considered: the occurrence of cracking and/or chipping (event 1) and catastrophic failure (event 2). The load (N) and number of cycles to failure in which events 1 and 2 were observed were used to perform the survival analysis according to Kaplan-Meier and Log-Rank (Mantel- Cox; 95%). The fracture marks and failure mode of the crowns were evaluated and classified by optical stereomicroscope and scanning electron microscope. Finally, finite element analysis (FEA) was performed for both studies in order to evaluate the stress distribution over the crowns and adhesive interface. For Study A, the results of the fatigue test showed that, considering event 1 (cracking/chipping), the CI and CMI groups presented average to failure that were statistically significant compared to each other (733.33 N and 913.33 N, respectively), while the SMI group showed higher averages (1,020 N). Same pattern was observed for the number of cycles under fatigue for both groups. When considering event 2 (catastrophic failure), the three groups presented statistically similar means (~1,028 N). The FEA results showed that the CI group concentrated greater tensile stress than the CMI and SMI groups. For Study B, in the fatigue test, the LC+LEU group presented the highest average fatigue resistance (event 1: 913.33 N and event 2: 1033.33 N), while all other combinations of ceramic materials analyzed were statistically similar to each other, considering load and number of cycles. Regarding FEA, the groups with hybrid ceramics (HC+LC and HC+LEU) showed lower stress concentration peaks in the infrastructure than the groups with glass ceramics (LC+LEU and LEU+LC), however, on the other hand, concentrated greater tension at the adhesive interface. With this, it is concluded that the use of modified infrastructure is a viable and promising alternative for oral rehabilitation treatments, presenting satisfactory fatigue survival and adequate stress distribution. Furthermore, the combination of a lithium disilicate infrastructure and a leucite-based ceramic coating corresponds to the best approach considering the modified infrastructure.(AU)

Fixed-prosthodontics in Nigerian private practice settings

Context: Private practice dentistry is predominant in Nigeria. Audits of fixed-prosthodontic practice in these settings are rare and will highlight capacity and guide training. This study aimed to assess the scope and quality of fixed-prosthodontic practice in such settings in Nigeria. Objectives: The study sought to assess: Participants' sociodemographic and their diagnostic and preoperative practices. The quality of impression making and operative technique, reviews and maintenance, temporization practices and communication with the laboratory.The range of treatments given and provision of advanced treatments. Materials and Methods: An adapted questionnaire was administered electronically on Nigerian dentists practicing fixed-prosthodontics in private practice settings. Retrieved data underwent descriptive statistics and associations were tested with the Fischer's Exact and Chi-Square tests using IBM SPSS Statistics version 21. Statistical significance was set at p≤0.05. Results: A total of 100 valid responses with a male:female ratio of 2.1:1 from 16 states wereretrieved. Fifty-nine participants had only first degrees and mean experience was 14.3±9.5 years. There were 27 adequate responses with regards to range of treatments offered. Sixty-three participants practiced direct temporization. Twenty-one and 14 participants regularly practiced implantology and CAD/CAM dentistry respectively. Direct temporization was significantly associated with increasing education (X2=6.03, p=0,05) and experience (X2=13.2, p=0.03). Conclusion: Only a few Nigerian dentists in private practice gave an adequate range of treatment. Most of them prefer direct temporization. Implantology and CAD/CAM dentistry practice are improving, but are still not very common.

Clinical assessment of two inlay -retained bridge designs (proximal box-shaped and inlay shaped) in missing posterior teeth cases. (Randomized Clinical Trial) / Avaliação clínica de dois modelos de ponte fixa inlay (forma de caixa proximal e em forma de inlay) em casos de dentes posteriores ausentes. (Ensaio clínico randomizado)

Objective: This study aimed to evaluate the clinical performance of two inlay-retained bridge designs (proximal shaped and inlay shaped) in single missing posterior teeth cases. Material and Methods: A total of 70 cases with missing single posterior teeth were included in this study and divided into two groups with a 1:1 allocation ratio (n = 35 for each group). Group 1 (the control group): this group received an inlay retained bridge with inlay design on both abutments. Group 2 (the intervention group): this group received an inlay retained bridge with a proximal box on both abutments. PMMA resin (YAMAHACHI PMMA) was used for the try-in stage and monolithic zirconia (Katana, Kuraray) was used for the final restorations. The restoration surfaces were treated using sandblasting and Z-prime S (Bisco) and the cementation was done by using self-adhesive resin cement (Bisco). Fracture, marginal adaptation, postoperative sensitivity, caries, and gingivitis were assessed using the modified United States Public Health Service for restoration clinical assessments (MUSPHS standards) over 12 months of follow-up. Results: The results show there was no significant difference between the two groups. Kaplan-Meier survival curve was constructed to calculate the mean survival estimates of the two groups and we found that the two groups were clinically successful during a one-year follow-up. Conclusion: Both designs of inlay retained fixed dental prostheses revealed successful clinical performance in terms of Fracture, marginal adaptation, postoperative sensitivity, caries, and gingivitis (AU)

Objetivo: O objetivo deste estudo foi avaliar o desempenho clínico de dois modelos de ponte fixa por inlay (formato proximal e formato inlay) em casos de dentes posteriores perdidos. Material e Métodos: Um total de 70 casos com perda de um único dente posterior foi incluído neste estudo e dividido em dois grupos com uma razão de alocação de 1: 1 (n = 35 para cada grupo). Grupo 1 (grupo controle): Este grupo recebeu uma ponte fixa por inlay com deseho de inlay em ambos os pilares. Grupo 2 (grupo intervenção): Este grupo recebeu uma ponte fixa inlay com uma caixa proximal em ambos os pilares. Resina de PMMA (YAMAHACHI PMMA) foi usada para a etapa de try-in e a zircônia monolítica (Katana, Kuraray) foi utilizada para as restaurações finais. As superfícies das restaurações foram jateadas com Z-prime S (Bisco) e a cimentação realizada com cimento resinoso autoadesivo (Bisco). Fratura, adaptação marginal, sensibilidade pós-operatória, cárie e gengivite foram avaliadas usando o Serviço de Saúde Pública dos Estados Unidos modificado para avaliações clínicas de restauração (padrões MUSPHS) ao longo de 12 meses de acompanhamento. Resultados: Os resultados mostraram que não houve diferença significativa entre os dois grupos. A curva de sobrevida de Kaplan-Meier foi construída para calcular as estimativas de sobrevida média dos dois grupos e foi concluído que os dois grupos foram clinicamente bem-sucedidos durante um acompanhamento de um ano. Conclusão: Ambos os modelos de próteses dentárias fixas de inlay revelaram desempenho clínico bem-sucedido em termos de fratura, adaptação marginal, sensibilidade pós-operatória, cárie e gengivite(AU)

Patients' Management Patterns for Restorative Treatment Procedures: A 4-Year Overview at the Restorative Clinic of a Tertiary Hospital in Nigeria

Abstract Objective: To determine the patients' management pattern for restorative treatment procedures at the Restorative Dentistry Clinic at the Lagos State University Teaching Hospital (LASUTH). Material and Methods: A descriptive and retrospective study design was employed to determine patients' management patterns for the restorative treatment procedures at the Restorative Dentistry Clinic at LASUTH. Treatment records of patients who attended the Restorative Clinic at the Lagos State University Hospital, Ikeja, Lagos, Nigeria, from 2011 to 2014 were reviewed; the effective treatments during the period under review were recorded as treatment procedures and were recorded as operative, endodontic, fixed prosthodontics, and removable procedures. Results: A total of 14,437 (75%) operative; 1,353 (7.0%) endodontic; and 559 (2.9%) fixed prosthodontics and 2,852 (14.9%) removable prosthodontic procedures were carried out during the period under review. This study showed that operative procedures were the most performed restorative procedures, whereas removable prosthodontics and endodontic procedures ranked second and third, respectively, to operative procedures. Fixed prosthodontics procedures were the least performed restorative procedures. Conclusion: This study showed that more efforts were being expended by dentists on operative services compared to endodontic, removable, and fixed prosthodontics services combined. Comprehensive studies, embracing all disciplines of dentistry, should be carried out to determine the level of demand and clinical relevance of procedures in clinical dental practice and hence to set specific and general objectives of dental education for the populace. Access to dental health Insurance services should also be increased in the country.

Tasa de supervivencia de prótesis fija unitaria de cerámica feldespática y feldespática reforzada / Survival rate of feldspathic and reinforced feldspathic ceramic single-unit fixed prostheses

Introducción: Gracias a su eficiencia y al uso exclusivo de cerámicas libres de metal, en rehabilitación oral se ha logrado alcanzar los estándares estéticos y mecánicos, manteniendo o, incluso, superando, la calidad de los tratamientos en comparación con las restauraciones metal cerámicas tradicionales. Actualmente los mecanismos de confeccion de cerámica libre están evolucionando cada vez mas hacia las tecnologías maquinadas CAD-CAM y disminuyendo su producción mediante la técnica de Inyeccion PRESS. Objetivo: Comparar la tasa de supervivencia de prótesis fija unitaria realizadas con cerámicas feldespáticas convencionales y reforzadas con disilicato de litio, confeccionadas con sistema CAD/CAM de CEREC® chair-side, en comparación con el método de inyección de laboratorio PRESS convencional de prensión. Métodos: Revisión sistemática realizada a través de búsqueda de evidencia científica en PubMed, PubMed Clinical Queries, Epistemónikos, Tripdatabase, Cochrane Library, recursos electrónicos de la Universidad de los Andes y bibliografía retrógrada, de artículos publicados hasta el año 2019. Se incluyeron todos aquellos estudios referentes a prótesis fija unitaria de cerámicas feldespática convencional y feldespática reforzada con disilicato de litio, confeccionadas mediante CAD/CAM y/o método convencional. Resultados: Un total de 28 artículos cumplieron los criterios de inclusión: 21 estudios observacionales de cohorte, 4 ensayos clínicos aleatorizados y 3 no aleatorizados. A corto y mediano plazo, CAD/CAM de CEREC® registró tasas de supervivencia de 98 por ciento y 91,9 por ciento, respectivamente. El sistema convencional registró tasas de supervivencia de 97,5 por ciento a corto plazo y 93 por ciento a mediano. Conclusiones: A corto plazo se describe en la literatura que CAD/CAM de CEREC® tuvo una tasa de supervivencia ligeramente superior al sistema convencional. Por otro lado, a mediano plazo CAD/CAM de CEREC® presentó una leve disminución respecto al sistema convencional. Aún no hay estudios disponibles para determinar la supervivencia clínica de los tratamientos a largo plazo(AU)

Introduction: Thanks to its efficiency and the exclusive use of metal-free ceramics, in oral rehabilitation it has been possible to achieve aesthetic and mechanical standards, maintaining or even exceeding the quality of the treatments compared to traditional metal-ceramic restorations. Currently, free ceramic manufacturing mechanisms are increasingly evolving towards CAD-CAM machined technologies and decreasing their conventional production through the PRESS Injection technique. Objective: Compare the survival rate of single-unit fixed prostheses made with conventional feldspathic ceramics and reinforced with lithium disilicate by the CEREC® CAD/CAM chairside system, with the conventional PRESS laboratory injection method. Methods: A systematic review was conducted of scientific evidence included in papers published until the year 2019 in PubMed, PubMed Clinical Queries, Epistemonikos, Tripdatabase, Cochrane Library, electronic resources of Los Andes Peruvian University, and retrograde bibliography. The papers selected dealt with conventional and lithium-disilicate reinforced feldspathic ceramic single-unit prostheses made by CAD/CAM and/or the conventional method. Results: A total 28 papers met the inclusion criteria. Of these, 21 were observational cohort studies, four were randomized clinical assays and three were non-randomized assays. Short- and mid-term, CEREC® CAD/CAM achieved survival rates of 98 percent and 91.9 percent, respectively. The conventional system achieved survival rates of 97.5 percent short-term and 93 percent mid-term. Conclusions: As described in the literature, CEREC® CAD/CAM had a slightly higher survival rate than the conventional system in the short term. In the medium term, however, CEREC® CAD/CAM displayed a slight reduction in comparison with the conventional system. No studies are available to determine the clinical survival of the treatments in the long term(AU)

Maxillary Occlusion rehabilitation of multiple anterior teeth agenesis followed by tooth wear: A case report

@#A 19-year-old female patient came with the chief complaint that the upper anterior teeth looked small and with many spaces. The patient claimed that the tooth had never been replaced since birth. The patient wanted to improve the aesthetics of the tooth. Treatment, in this case, was made using a fixed prosthetic to aesthetically rehabilitate through prosthodontic treatment in the anterior teeth agenesis followed by attrition. It can be concluded that fixed prosthodontic treatment using a splint bridge is one treatment option that can be used in multiple anterior teeth agenesis followed by tooth wear. An appropriate material selection increases the aesthetics and functional aspects of the final treatment.

Complicações precoces em próteses parciais fixas implantossuportadas de zircônia monolítica e bicamada: estudo prospectivo, randomizado, de boca dividida / Early complications in fixed partial prosthesis implants supported with monolithic and bilayer zirconia: a prospective, randomized, split-mouth study

As coroas de cerâmica pura estão ganhando força na odontologia uma vez que as exigências estéticas e mecânicas são cada vez mais evidentes, uma vez que as próteses metal free do tipo bicamada, não raramente, apresentam lascamento da cerâmica de cobertura como a principal falha a longo prazo, então iniciou-se o uso de próteses monolíticas. Paralelamente é crescente a busca e o uso de implantes osseointegráveis para suportar as reabilitações parciais, sendo a primeira opção para as reabilitações orais de áreas edêntulas. Logo, o objetivo deste estudo clínico prospectivo, randomizado de boca dividida é avaliar o desempenho clínico e a previsibilidade, caracterizando o número e o tipo de complicações e falhas precoces como desgaste do antagonista, perda óssea, inflamação gengival e falhas mecânicas que possam ocorrer em PPFs de três elementos implantossuportadas com retenção mista em região posterior de mandíbula em zircônia monolítica e infraestrutura de zircônia com cerâmica de cobertura, além de avaliar a percepção estética e satisfação do paciente com cada uma delas. Os pacientes selecionados (N=2) passarão por procedimentos cirúrgicos para instalação de dois implantes na região posterior de mandíbula, sendo dois de cada lado. Após três a quatro meses os cicatrizadores serão instalados e a moldagem será realizada para confecção das próteses seguindo a aleatorização do lado da mandíbula. Serão avaliados desgaste das próteses e dos antagonistas por meio de microscopia eletrônica de varredura; perda óssea periimplantar utilizando radiografias periapicais em três períodos, imediatamente após a instalação das próteses, uma semana após e três meses depois, percepção estética e alteração de cor utilizando o método de escala visual analógica pelo paciente. As hipóteses deste estudo são resistência à fratura e lascamento será semelhante nos grupos avaliados, todos os grupos serão esticamente aceitáveis, o desgaste do antagonista e das próteses será semelhante entre os grupos e a manutenção periodontal e nível de perda óssea será semelhante para os grupos(AU)

The pure ceramic crowns have been gaining strength in dentistry since the aesthetic and mechanical requirements are increasingly evident. Since free metal dentures of the bilayer type, not infrequently, show sputtering of the ceramic cover as the main long-term failure, the use of monolithic prostheses was started. At the same time, the search for and use of osseointegratable implants to support partial rehabilitation is increasing, being the first option for oral rehabilitation of edentulous areas. Therefore, the purpose of this prospective, randomized, split-mouth clinical study is to assess clinical performance and predictability, characterizing the number and type of early complications and failures such as antagonist wear, bone loss, gingival inflammation, and mechanical failures that may occur in PPFs of three implant - supported elements with mixed retention in posterior region of mandible in monolithic zirconia, zirconia infrastructure with covering ceramics and metaloceramics, besides evaluating aesthetic perception and patient satisfaction with each one. Patients selected (n = 8) will undergo surgical procedures to install two implants in the posterior mandible, two on each side. After three to four months the healing will be installed and the molding will be performed to make the prosthesis following the randomization of both the patients and the side of the jaw. Wear of prostheses and antagonists will be assessed by scanning electron microscopy and profilometry; bone loss peri-implant using periapical radiographs in seven periods, immediately after the implant installation, 7 days after surgery, before the installation of the healers, at the installation of the prosthesis, 21 days after, six and twelve months later, aesthetic perception and color change using the method of visual analog scale by the patient and an intraoral spectophotometer. The hypotheses of this study are resistance to fracture and chipping will be similar in the evaluated groups, all groups will be ethically acceptable, the wear of the antagonist and the prostheses will be similar between groups and the periodontal maintenance and level of bone loss will be similar for the groups(AU)

Infiltration by Streptococcus mutans in provisional crowns fixed by two types of cementing agents ­ pilot double-blind randomized clinical trial / Infiltração por Streptococcus mutans em coroas dentárias provisórias fixadas por dois tipos de agentes cimentantes ­ estudo clínico randomizado duplo-cego piloto

Objective: When provisional acrylic crowns are used for a long time, they become more susceptible to marginal leakage by cariogenic bacteria. The objectives of this pilot clinical study were to compare cement based on zinc oxide-eugenol and calcium hydroxide by contamination with Streptococcus mutans, and calculate the sample size for the continuation of this study. Methods: Individuals receiving provisional crowns and following inclusion/exclusion criteria, were randomly distributed into 2 groups: zinc oxide-eugenol (n=8); calcium hydroxide (n=9). The temporary crowns were made by a blind researcher and cemented by another. Patients were also blinded by the cement used inside their crowns. After 2 months, a cement sample from the crowns' peripheral inner face was collected, placed in a tube containing 1 mL of sterile saline, serially diluted, plated on Mitis Salivarius Bacitracin agar, and incubated for 48 hours. Colony-forming units (CFU/mL) were counted. A statistical power analysis was performed to calculate sample size (1-ß=80%) and the Mann Whitney test to compare both cements (α=0.05). Results: Both cements were contaminated with S. mutans, with an average of 166.6 x 102 CFU/mL for calcium hydroxide and 435.3 x 102 CFU/mL for zinc oxide-eugenol, with no significant difference (p=0.311). The sample size calculated for this study was 36 per group. Conclusion: This pilot study suggests that there is important contamination inside provisional crowns used for two months, independent of the cement. The continuation of this study is needed, with a bigger sample size, to enable a comparison between the cements.

Objetivo: Quando coroas dentais provisórias são utilizadas por um longo período, elas se tornam susceptíveis à infiltração marginal por bactérias cariogênicas. O objetivo deste estudo clínico piloto foi comparar os cimentos a base de óxido de zinco e eugenol e hidróxido de cálcio pela contaminação com Streptococcus mutans e calcular o tamanho amostral para continuação deste estudo. Métodos: Indivíduos recebendo coroas provisórias e seguindo critérios de inclusão/exclusão, foram distribuídos aleatoriamente em dois grupos: óxido de zinco e eugenol (n=8); hidróxido de cálcio (n=9). As coroas provisórias foram feitas por um pesquisador cego e cimentadas por outro. Os pacientes também foram cegos quanto ao cimento utilizado dentro de suas coroas. Depois de 2 meses, amostras de cimentos foram coletadas da face interna periférica das coroas, colocadas em um tubo contendo 1 mL de solução salina estéril, diluídas de forma seriada, plaqueadas em ágar Mitis Salivarius Bacitracina e incubadas por 48 horas. Unidades formadoras de colônias (UFC/mL) foram contadas. Um teste de poder estatístico foi realizado para calcular o tamanho amostral (1-ß=80%) e o teste de Mann Whitney para comparar os dois cimentos (α=0.05). Resultados: Os dois cimentos foram contaminados com S. mutans, com uma média de 166.6 x 102 UFC/mL para o hidróxido de cálcio e 435.3 x 102 UFC/mL para o óxido de zinco e eugenol, com nenhuma diferença significativa (p=0.311). O cálculo amostral para este estudo foi 36 indivíduos por grupo. Conclusão: Este estudo piloto sugere que existe importante contaminação dentro de coroas provisórias utilizadas por 2 meses, independente do cimento. A continuação deste estudo é necessária, com maior tamanho amostral, para possibilitar a comparação entre os cimentos.

Estudo comparativo de ferramentas de aprendizagem para preparos dentários em prótese fixa / Comparative study of learning tools for dental preparations in fixed prosthesis

No tocante ao ensino teórico-prático em prótese fixa docentes utilizam diversos recursos didáticos no intuito de implementar estratégias de como realizar tecnicamente preparos (desgastes) dentais coronários visando a reposição de estruturas dentais por próteses, a fim de formar um conceito e fixar a imagem de um preparo ideal; conteúdo esse que deve ser aplicado e refinado na prática odontológica tanto laboratorial quanto clinicamente. O presente estudo teve como objetivo validar duas ferramentas novas no ensino e aprendizagem do conteúdo da disciplina de Prótese Fixa, a partir das principais dificuldades dos alunos em realizar um preparo. Participaram da pesquisa 61 alunos da graduação em Odontologia. Duas metodologias foram avaliadas quanto a sua eficácia na melhora do preparo final realizado pelo aluno: 1) Aplicativo de celular contendo um banco de dados com os principais preparos coronários e, 2) Um manequim com esquema de cores que auxilia a visualizar e calibrar os alunos na quantidade de redução coronária nos preparos. Como metodologia os alunos realizaram o preparo de um dente íntegro antes e após o uso das ferramentas didáticas do aplicativo e manequim. Os preparos foram escaneados e um software de análise de deformidade de superfície avaliou a diferença entre o preparo inicial e o valor de referência, preparo realizado após a aplicação da metodologia x valor de referência, podendo assim ser inferida a possível melhora no resultado da aplicação da metodologia comparativamente ao conceito teórico de um preparo ideal. Os dados computados foram analisados estatisticamente pelo test t com nível de significância estabelecido foi de p<0,05. A metodologia do aplicativo de celular mostrou poucas diferenças estatísticas quando comparado ao método do manequim com esquema de cores. O manequim esclareceu e mostrou resultados otimistas nas 3 das principais dificuldades dos alunos relatadas no questionário inicial, quantidade de desgaste, término cervical e inclinação e angulação dos preparos. Ambas as metodologias, respectivamente aplicativo e manequim, foram aprovadas 96,77% e 98,39% dos alunos e validadas como metodologias auxiliares ao ensino em PPF e odontologia pelo seu conteúdo teórico e prática associada (AU)

With regard to theoretical-practical teaching in fixed prostheses, teachers use several teaching resources in order to implement strategies on how to technically perform coronal dental preparations (wear) in order to replace dental structures with prostheses, in order to form a concept and fix the image of an ideal preparation; content that must be applied and refined in dental practice both laboratory and clinically. The present study aimed to validate two new tools in the teaching and learning of the content of the Fixed Prosthesis subject, based on the main difficulties of the students in carrying out a preparation. Sixty-one undergraduate students in Dentistry participated in the research. Two methodologies were evaluated for their effectiveness in improving the final preparation performed by the student: 1) Mobile application containing a database with the main coronary preparations and, 2) A mannequin with a color scheme that helps to visualize and calibrate students on the amount of coronary reduction in the preparations. As a methodology, the students prepared an intact tooth before and after using the didactic tools of the application and dummy. The preparations were scanned and a surface deformity analysis software evaluated the difference between the initial preparation and the reference value, preparation carried out after the application of the methodology x reference value, thus being able to infer the possible improvement in the result of the application of the methodology compared to the theoretical concept of an ideal preparation. The computed data were statistically analyzed by the t test with a significance level of p<0.05. The cell phone application methodology showed few statistical differences when compared to the color scheme dummy method. The dummy clarified and showed optimistic results in the 3 of the main difficulties of the students reported in the initial questionnaire, amount of wear, cervical end and inclination and angulation of the preparations. Both methodologies, respectively application and mannequin, were approved by 96.77% and 98.39% of students and validated as auxiliary methodologies for teaching in PPF and dentistry for their theoretical content and associated practice (AU)

Cirugía guiada para la colocación de implantes de longitud estándar en maxilar inferior posterior atrófico, sin regeneración ósea: informe de caso / Use of guided surgery for standard length implant placement in atrophic posterior mandible, without bone regeneration: case report

Objetivo: Presentar el uso de la cirugía guiada para la resolución quirúrgico-protética de un caso clínico con colocación de implantes de longitud estándar (>7 mm) en un maxilar inferior atrófico, sin regeneración ósea guiada. Caso clínico: Una paciente que requería terapia con implantes en sectores posteroinferiores se presentó en la Cátedra de Odontología Integral Adultos de la Facultad de Odontología de la Universidad de Buenos Aires. Primero se realizó una tomografía computarizada de haz cónico del maxilar inferior para evaluar la disponibilidad ósea. La planificación se efectuó siguiendo un protocolo digital a fin de optimizar la selección de los implantes y su instalación en función de la futura rehabilitación protética y el tejido óseo disponible. Después se escanearon ambos maxilares y el registro intermaxilar; estas imágenes ­junto con las correspondientes a la tomografía (DICOM)­ fueron importadas como archivos (STL) a un software específico de diseño para determinar digitalmente la posición 3D ideal de los implantes y diseñar una guía quirúrgica de precisión. Luego se realizó la cirugía de instalación de los implantes con la guía quirúrgica, y finalmente los implantes fueron rehabilitados por medio de coronas cemento-atornilladas. Conclusión: El uso de la cirugía guiada permitió optimizar el tejido óseo disponible para la instalación de implantes en función de la futura rehabilitación protética (AU)

Aim: To present the use of guided surgery for the prosthetic resolution of a clinical case with placement of implants of standard length (>7 mm) in an atrophic posterior mandible, with no need of bone regeneration. Clinical case: A patient who required implants in the posterior sectors of the mandible attended to the department of Odontología Integral Adultos, Facultad de Odontología, Universidad de Buenos Aires, Argentina. A dental cone beam computed tomography (CBCT scan) of the lower jaw was done to assess bone availability and was decided to perform guided surgery for accurate implant placement. Both maxillaries and intermaxillary occlusal registration were scanned and imported into files (STL) together with those of the CBCT scan (DICOM) into specific design software. Following the digital protocol using a surgical guide the implants were placed and then restored with cemented-screwed crowns. Conclusion: Guided surgery allowed planning implant placement, guided by the final position of the prosthetic restoration, and optimizing the available bone (AU)

Perceptions of rehabilitated patients with fixed partial dentures as to the temporary restoration

ABSTRACT: This study evaluated patients' perceptions regarding the installation of temporary fixed partial denture (TFPD). A questionnaire developed that addressed patients' perceptions about the temporary restorations, applied to patients after concluded their treatment. Responses were analyzed by descriptive statistics and contingency tables were constructed to statistically analyze the relationship between patients' perceptions of age, gender and type of prosthesis. We interviewed 28 patients (23 female; 5 male). In the results, 53.57% of the patients reported improvement in the chewing, 3.57% of the patients reported an improvement in speech, 21.43% of patients reported improvement in both aspects and another 21.43% of patients did not report functional improvements in speech and in chewing. Regarding dental pain, 89.28% did not present. In the hygienization aspect, 46.42% of the patients had difficulty, and 25% of the patients had bleeding gum. Finally, 89.28% of the patients reported that a TFPD made it possible to predict the final treatment outcome. No statistically significant difference was found when age (p = 0.86062) and gender (p=0.41225) were correlated. However, the type of prosthesis influenced patients' perceptions of TFPDs (p = 0.01254). It is concluded that TFPD is an important step in the treatment with fixed prosthesis.

Conformación de póntico E en sector anterior / Pontic E conformation at anterior sector

El póntico E es una alternativa de tratamiento para la pérdida prematura dental, este tipo de póntico fue publicado por primera vez en 2014 por Robert P. Korman. El diseño del póntico permite ofrecer predictibilidad en cuanto a soporte y mantenimiento de la arquitectura gingival, también promueve que el tejido vestibular migre coronalmente sobre el póntico, creando un surco gingival. Se recibió a una paciente que presentaba fragmento radicular del diente 21 y ausencia del diente 12, reborde residual atrófico (clase I según Seibert). Como plan de tratamiento, se realizó la extracción atraumática del fragmento radicular del diente 21 para retardar el colapso del reborde alveolar y se colocó injerto de tejido conectivo en la zona del diente 12 para corregir el defecto clase I de Seibert, se realizó la conformación de los nichos gingivales con electrobisturí en conjunto con la prótesis provisional y la preparación de los dientes pilares para la recepción y rehabilitación con pónticos E. Se colocó una prótesis fija de cinco unidades (dientes 13 al 23) en material núcleo de Zr y estratificada con cerámica (AU)

Pontic E is an alternative treatment for premature dental loss, this type of pontic was published for the first time in 2014 by Robert P. Korman. The design of the pontic allows to offer predictability in terms of support and maintenance of the gingival architecture, it also promotes that the vestibular tissue migrates coronally over the pontic, creating a gingival groove. A patient was received who presented a radicular fragment of tooth 21 and absence of tooth 12, atrophic residual ridge (class I according to Seibert). As a treatment plan, atraumatic extraction of the root fragment of tooth 21 was performed to delay the collapse of the alveolar ridge and connective tissue graft was placed in the area of tooth 12 to correct Seibert's class I defect, conformation was performed of the gingival niches with electrocautery in conjunction with the provisional prosthesis and the preparation of the abutment teeth for the reception and rehabilitation with pontics E. A fixed prosthesis of five units was placed (teeth from 13 to 23) of Zr core material and stratified with ceramic (AU)

Characteristics of Mandibular Movement and Mastication in Older Adults with Removable Dental Prostheses: Three-Dimensional Analysis / Características de Movimientos Mandibulares y Masticación en Adultos Mayores con Prótesis Dental Removible: un Análisis Tridimensional

ABSTRACT: Aging is a dynamic process that includes various alterations in the oral cavity, with tooth loss being the most frequent. Rehabilitative treatment may include removable or fixed prostheses and implants. The aim of this study was to describe the geometric (trajectory, ranges, areas) and kinematic (speed) characteristics of the mandibular and masticatory movements threedimensionally in participants with dental prostheses. A sample of 10 participants with removable prosthetic rehabilitation was divided into three groups (complete, atypical and overdenture) the characteristics of mandibular movements bordering and chewing with 3D Electromagnetic Articulography were measured. The Posselt polygonin was obtained, the frontal and sagittal plans, its areas, trajectories and ranges are analyzed. The masticatory movements were analyzed in the area of each cycle, the frequency, the speed and the reason between the masticatory cycle and the bordering movements, no significant differences between the groups. Subjects with dental prostheses, regardless of the type, they showed low of motion (border and functional) compared to dentate subjects with no functional alterations whose values have been reported in the literature. The subjects with overdenture have values closer to what is described for young dentate subjects.

RESUMEN: El envejecimiento es un proceso dinámico que incluye varias alteraciones en la cavidad oral, siendo la pérdida de dientes la más frecuente. El tratamiento de rehabilitación puede incluir prótesis fijas o removibles y/o implantes. El objetivo de este estudio fue describir las características geométricas (trayectoria, rangos, áreas) y cinemáticas (velocidad) de los movimientos mandibulares y masticatorios en participantes con prótesis dentales realizando un análisis en tres dimensiones. Se consideró una muestra de 10 participantes con rehabilitación protésica y se dividió en tres grupos (prótesis total, atípica e implantosoportada), se midieron las características de los movimientos mandibulares bordeantes y masticatorios con articulografía electromagnética 3D. Se obtuvo el polígono Posselt en los planos frontal y sagital, se analizaron sus áreas, trayectorias y rangos. Se analizaron los movimientos masticatorios en cuanto al área de cada ciclo, la frecuencia, la velocidad y la razón entre el área el ciclo masticatorio y los movimientos bordeantes, sin diferencias significativas entre los grupos. Los sujetos con prótesis dentales, independientemente del tipo, mostraron disminución de movimiento (bordeante y funcional) en comparación con los sujetos dentados sin alteraciones funcionales cuyos valores se han informado en la literatura. Los sujetos con prótesis implantosoportada tienen valores más cercanos a lo que se describe para sujetos jóvenes dentados.

Salud bucal en una escuela de formación profesional policial peruana / Oral health at a Peruvian police academy

RESUMEN Introducción: La salud bucal en el adulto joven es un derecho humano básico, y su contribución es fundamental para el goce de buena calidad de vida. Objetivo: Determinar la salud bucal en una escuela de formación profesional policial peruana en el período de julio a agosto del 2017. Métodos: Estudio observacional descriptivo de corte transversal. La muestra estuvo conformada por 276 adultos jóvenes seleccionados aleatoriamente, cumpliendo criterios de inclusión y exclusión, según las normas éticas en investigación científica. Se evaluó la salud bucal mediante una ficha epidemiológica con los indicadores: índice CPOD, índice de significancia de caries dental (SIC), índice de higiene oral simplificado (IHO-S) y el índice de necesidad y situación de prótesis dental de la OMS. La evaluación se realizó con luz natural por un observador calibrado. Los datos se analizaron en el programa STATA v 14 mediante tablas de distribución de frecuencias y figuras. Resultados: La prevalencia de caries dental fue de 63,76 por ciento (CPOD= 3,86; SIC= 9,64), IHO-S: 2,02 (DS= 0,41). La prótesis parcial fija fue la que más se usó y se necesitó en ambos maxilares. Conclusiones: La experiencia de caries dental fue moderada, la condición de higiene oral fue regular, y la prótesis parcial fija fue la que más se necesitó y se uso en ambos maxilares. Aunque los indicadores son alentadores, aún urge la necesidad de implementar políticas sanitarias en salud bucal en la comunidad policial(AU)

ABSTRACT Introduction: The oral health of young adults is a basic human right, and its contribution is fundamental for the enjoyment of a good quality of life. Objective: Determine oral health at a Peruvian police academy from July to August 2017. Methods: An observational descriptive cross-sectional study was conducted. The sample was 276 young adults randomly selected according to inclusion and exclusion criteria and in compliance with the ethical standards of scientific research. Oral health was evaluated with the aid of an epidemiological card containing the following indicators: CPOD index, dental caries significance (DCS) index, simplified oral hygiene index (OHI-S), and WHO dental prosthesis need and situation. The evaluation was conducted by a qualified observer under natural light. Data were processed with the software STATA v 14, using frequency distribution tables and figures. Results: Dental caries prevalence was 63.76 percent (CPOD= 3.86; DCS= 9.64), OHI-S: 2.02 (SD= 0.41). Fixed partial dentures were the most commonly used, and they were required in both jaws. Conclusions: Dental caries experience was moderate, oral hygiene status was fair, and fixed partial dentures were the most commonly required for both jaws. Although the indicators are heartening, there is still an urgent need to implement oral health policies in the police community(AU)

Prótese Parcial Fixa em Cantilever, uma opção de tratamento: Revisão da Literatura / Fixed Partial Denture with Cantilever an option for therapeutic: Literature Review

Hoje em dia no consultório a indicação de uma prótese fixa em cantilever, ainda gera muitas dúvidas, levando o clinico inseguro, muitas vezes a sua contra indicação. Com intuito de esclarecer as características relacionadas à prótese parcial fixa em cantilever realizou- -se uma revisão de literatura. Uma busca foi realizada nas bases de dados Scielo e Pubmed usando-se as palavras-chaves: Prótese fixa, cantilever, dentes suportes. Os artigos dentro do escopo do estudo foram selecionados e pode-se concluir que estas próteses são uma excelente alternativa conservadora para restabelecimento de dentes perdidos, porém para obtenção de resultados satisfatórios com boa longevidade, especial atenção deve ser desprendida aos princípios biomecânicos dos preparos e um controle rigoroso de placa bacteriana deve ser estabelecido.

Actuality the use of Fixed Partial Denture with Cantilever until causes many doubts, making de dentist do not indicate this treatment. To making clear the characteristics relation to this prosthesis, was done a literature review. A search was performed in the Scielo and Pubmed databases using the keywords: Fixed prosthesis, cantilever, supporting teeth. The articles within the scope of the study were selected and it can be concluded that these were an alternative excellent to reestablish the follow teeth, therefore to obtain the good results with respect long-term prosthetic appliances, special attention should be dispensed to the biomechanics principles and optimal hygiene with plaque control should be established.

Fiber-reinforced composite resin bridges: an alternative method to treat root-fractured teeth

The replacement of missing teeth, especially in the anterior region, is an essential part of dental practice. Fiber-reinforced composite resin bridges are a conservative alternative to conventional fixed dental prostheses or implants. It is a minimally invasive, reversible technique that can be completed in a single visit. The two cases presented herein exemplify the treatment of root-fractured anterior teeth with a natural pontic immediately after extraction.

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.

Prevalencia e intensidad de sensibilidad posoperatoria durante el tratamiento de prótesis fija / Prevalence and intensity of postoperative hypersensitivity during fixed prosthodontic treatment

RESUMEN Introducción: Durante la realización de prótesis fijas, el paciente puede presentar sensibilidad posoperatoria. Se ha descrito en la literatura diferentes prevalencias de esta sensibilidad, las cuales varían ampliamente, entre 3 por ciento y 34 por ciento. Objetivo: Determinar la prevalencia e intensidad de sensibilidad posoperatoria en el tratamiento de prótesis fija sobre diente vital. Métodos: se realizó un estudio clínico piloto descriptivo. La muestra fue de 35 dientes tratados de 20 pacientes. Esta fue conformada por pacientes atendidos por alumnos del Centro Odontológico de la Universidad de Los Andes, a los cuales se les realizó un tratamiento en base a prótesis fija sobre diente vital, desde el mes de abril hasta octubre del año 2015. Se registró la sensibilidad durante el tratamiento por medio la escala visual análoga a través de un diario completado por el paciente y por la escala verbal numérica aplicada por el investigador en distintas etapas clínicas. Resultados: Se observó una prevalencia del 31,4 por ciento con una intensidad de 0,62 ± 0,49 según la escala visual análoga y de 0 según la escala verbal numérica. Conclusiones: la prevalencia de la sensibilidad posoperatoria se aproximó al rango más alto descrito en la literatura. La intensidad de la sensibilidad observada fue leve a imperceptible clínicamente(AU)

ABSTRACT Introduction: During fixed prosthodontic treatment, patients may present postoperative hypersensitivity. The prevalence rates contained in the literature on the topic range from a mere 3 percent to 34 percent. Objective: Determine the prevalence and intensity of postoperative hypersensitivity during fixed prosthodontic treatment of vital teeth. Methods: A pilot descriptive clinical study was conducted. The sample was 35 treated teeth from 20 patients. These patients had been treated by students from the Dental Center at the University of Los Andes, and had undergone fixed prosthodontic treatment on vital teeth from April to October 2015. Hypersensitivity during the treatment was recorded with the visual analog scale based on a diary kept by patients and on the verbal numerical rating scale as applied by the researcher at the various clinical stages. Results: Prevalence was 31.4 percent with an intensity of 0.62 ± 0.49 by the visual analog scale and of 0 by the verbal numerical rating scale. Conclusions: The prevalence of postoperative hypersensitivity approached the highest range described in the literature, whereas the intensity of hypersensitivity ranged from mild to clinically imperceptible(AU)

Alternativa de tratamento reabilitador para pacientes em uso de bisfosfonato intravenoso: relato de caso clínico / An alternative rehabilitation treatment for patients using intravenous bisphosphonate: clinical case report

O objetivo deste relato de caso clínico foi descrever a importância de planejar de maneira minuciosa uma alternativa de reabilitação conservadora de um paciente em uso de bisfosfonato intravenoso, bem como detalhar os procedimentos realizados. Paciente do gênero masculino, 78 anos, buscou atendimento odontológico relatando insatisfação com sua condição dentária atual, e o desejo de realizar novas próteses dentárias. Ao exame clínico, observou-se instabilidade da prótese parcial removível superior devido à fratura coronária do elemento 26. Ao exame radiográfico, observaram-se extensas lesões cariosas nos dentes 16 e 26. Após plano de tratamento realizado em equipe multidisciplinar, foi sugerida uma reabilitação sem nenhum procedimento cirúrgico, a fim de minimizar as complicações pós-operatórias e proporcionar saúde oral de maneira mais breve e minimamente invasiva. O tratamento incluiu a confecção de uma prótese parcial fixa dos elementos 13 ao 23 com encaixes de precisão associada à uma prótese parcial removível superior. Já para a arcada inferior, foi realizada uma prótese parcial fixa dos elementos 33 ao 41 e uma prótese parcial removível. Por meio deste caso clinico, foi possível concluir que uma abordagem conservadora possibilitou uma reabilitação que supriu as necessidades estéticas e funcionais do paciente que faz uso de medicamento antirreabsortivo(AU)

The aim of this study was to describe the importance of a carefully planning to conservative rehabilitation alternative for a patient using intravenous bisphosphonate, as well as to detail the procedures performed. A male patient, 78 years old, sought dental care reporting dissatisfaction with his current dental condition and the desire to perform new dental prostheses. At the clinical examination, instability of the superior removable partial denture was observed due to the coronary fracture of element 26. Radiographic examination revealed extensive carious lesions on teeth 16 and 26. After a multidisciplinary treatment planning, was suggested a rehabilitation without any surgical procedure, in order to minimize postoperative complications and provide oral health in a minor and minimally invasive manner. Treatment included a fixed partial denture of elements 13 to 23 with precision fittings attachments associated with a removable partial denture. To the jaw, a fixed partial prosthesis of elements 33 to 41 and a partial removable prosthesis were performed. Through this clinical case, it was possible to conclude that a conservative management provides an aesthetical and functional patient rehabilitation who take antiresorptive medication(AU)