RESUMO
Na formação em Odontologia os acadêmicos realizam treinos pré-clínicos para aperfeiçoar suas técnicas. O objetivo deste estudo é relatar a experiência de produção de dentes decíduos artificiais por impressão tridimensional (3D), com baixo custo, para práticas laboratoriais acadêmicas em Odontopediatria. Partiu-se de uma pesquisa laboratorial e experimental, tendo sido realizada uma revisão bibliográfica para obtenção dos dados. A obtenção das imagens 3D se deu a partir da biblioteca gratuita de dentes permanentes Brenner e edição no programa Meshmixer para incorporação das características de dentes decíduos, seguida de impressão 3D utilizando estereolitografia. Posteriormente, foram preenchidos os condutos radiculares com cera 7 e poliacetato de vinila (PVA)vermelha. Foi realizada também a pintura do cemento e da coroa, com tinta de esmalte marrom e branca, respectivamente. As duas resinas exibiram fidelidade anatômica externa, entretanto, para viabilidade do uso na Endodontia, foi analisada a anatomia interna, imagem radiográfica, tempo de impressão, custo de produção e custo/benefício. A combinação de resina Anycubic para a representação dos tecidos mineralizados com cera 7 para simulação da polpa possibilitou a adequada reprodução da anatomia interna de dentes decíduos (AU).
En la formación en Odontología, los alumnos realizan una formación preclínica para mejorar sus técnicas. El objetivo de este estudio es relatar la experiencia de producción de dientes temporales artificiales por impresión tridimensional (3D), a bajo costo,para prácticas académicas de laboratorio en Odontopediatría. Se inició con una investigación de laboratorio y experimental, habiéndose realizado una revisión bibliográfica para la obtención de los datos. Las imágenes 3D se obtuvieran de la biblioteca gratuita de dientes permanentes de Brenner y se editó en el programa Meshmixer para incorporar las características de los dientes temporales, seguida de una impresión 3D mediante estereolitografía. Posteriormente se obturaron los conductos radiculares con cera7 y acetato de polivinilo rojo (PVA). El cemento y la corona también se pintaron con pintura de esmalte marrón y blanco, respectivamente. Las dos resinas exhibieron fidelidad anatómica externa, sin embargo, para la factibilidad de uso en Endodoncia se analizó la anatomía interna, imagen radiográfica, tiempo de impresión, costo de producción y costo/beneficio. La combinación de la resina Anycubic para la representación de tejidos mineralizados con la cera 7 para la simulación de la pulpa permitió reproduciradecuadamente la anatomía interna de los dientes temporales (AU).
During Dentistry training, students undertake pre-clinical training to improve their techniques. The objective of this study is to report the experience of producing artificial deciduous teeth using three-dimensional (3D) printing, at low cost, for academic laboratory practices in Pediatric Dentistry. The starting point was laboratory and experimental research, and a bibliographic review was carried out to obtain data. The 3D images were obtained from the free Brenner permanent teeth library and edited in the Meshmixer program to incorporate the characteristics of deciduous teeth, followed by 3D printing using stereolithography. Subsequently, the root canals were filled with wax 7 and red polyvinyl acetate (PVA). The cementum and crown were also painted with brown and white enamel paint, respectively. The two resins exhibited external anatomical fidelity, however, for feasibility of use in Endodontics, the internal anatomy, radiographic image, printing time, production cost and cost/benefit were analyzed. The combination of Anycubic resin to represent mineralized tissues with wax 7 to simulate the pulp made it possible to adequately reproduce the internal anatomy of deciduous teeth (AU).
Assuntos
Educação em Odontologia , Desenho Assistido por Computador/instrumentaçãoRESUMO
The accidental swallowing of prosthetic devices has been discussed in the relevant literature as an unusual, although ordinary, event in clinical practice. This article aims at reporting the ingestion of an inter-occlusal device used to restore the Vertical Dimension of Occlusion (VDO) which, during the ingestion of an analgesic pill, was accidentally swallowed. The patient was sent to the Clinics Hospital UFMG where, upon taking radiographs, the device was located in the upper third of the esophagus. The device was removed during an endoscopic exam with the help of forceps for removing foreign objects. Dealing with a relevant situation, one may conclude that patients who use removable intra-oral devices must take part in a reevaluation protocol in order to detect adaptation and retention of these devices, as well as proper instruction for the patient.
RESUMO
Objective: This study evaluated apical transportation associated with ProTaper® Universal Fl, F2 and F3 rotary files in curved canais prepared by undergraduate students. Material and Methods: Twenty mesial roots of mandibular molars with curvatures ranging between 25° and 35° were selected. Mesiobuccal canals were instrumented by twenty students with the ProTaper® system (Dentsply-Maillefer, Ballaigues, Switzerland) according to the manufacturer's instructions. Pre-fiaring was performed with Sl and SX files. A #15 K-file was inserted into the root canal up to the working length (WL), and an initial digital radiograph was taken in a buccolingual direction (baseline). Afterwards, the S1, S2, F1, F2, and F3 files were employed up to the WL. Other radiographies were taken in the same orientation of the baseline after the use of the Fl, F2, and F3 files, with each file inserted into the root canal. The radiographic images were overlapped, and the Image J software was used to measure the distance between the rotary files' ends and the #15 K-file's end, characterizing the apical transportation. Data were analyzed by Repeated Measure ANOVA and by the SNK post hoc test (P<0.05). Results: It was verified that file size affected apical transportation significantly (P<0.001). The F3 file showed higher apical transportation than Fl and F2, while between these last files there was no difference. Conclusion: The undergraduate students produced lower apical transportation in curved canals when they did not use the F3 rotary file. .
Assuntos
Humanos , Instrumentos Odontológicos , Cavidade Pulpar/anatomia & histologia , Preparo de Canal Radicular/instrumentação , Estudantes de Odontologia , Ápice Dentário/anatomia & histologia , Análise de Variância , Cavidade Pulpar , Desenho de Equipamento , Teste de Materiais , Níquel , Odontometria , Reprodutibilidade dos Testes , Preparo de Canal Radicular/métodos , Titânio , Ápice DentárioRESUMO
OBJECTIVE: This study evaluated apical transportation associated with ProTaper Universal Fl, F2 and F3 rotary files in curved canais prepared by undergraduate students. MATERIAL AND METHODS: Twenty mesial roots of mandibular molars with curvatures ranging between 25° and 35° were selected. Mesiobuccal canals were instrumented by twenty students with the ProTaper system (Dentsply-Maillefer, Ballaigues, Switzerland) according to the manufacturer's instructions. Pre-fiaring was performed with Sl and SX files. A #15 K-file was inserted into the root canal up to the working length (WL), and an initial digital radiograph was taken in a buccolingual direction (baseline). Afterwards, the S1, S2, F1, F2, and F3 files were employed up to the WL. Other radiographies were taken in the same orientation of the baseline after the use of the Fl, F2, and F3 files, with each file inserted into the root canal. The radiographic images were overlapped, and the Image J software was used to measure the distance between the rotary files' ends and the #15 K-file's end, characterizing the apical transportation. Data were analyzed by Repeated Measure ANOVA and by the SNK post hoc test (P<0.05). RESULTS: It was verified that file size affected apical transportation significantly (P<0.001). The F3 file showed higher apical transportation than Fl and F2, while between these last files there was no difference. CONCLUSION: The undergraduate students produced lower apical transportation in curved canals when they did not use the F3 rotary file.
Assuntos
Instrumentos Odontológicos , Cavidade Pulpar/anatomia & histologia , Preparo de Canal Radicular/instrumentação , Estudantes de Odontologia , Ápice Dentário/anatomia & histologia , Análise de Variância , Cavidade Pulpar/diagnóstico por imagem , Desenho de Equipamento , Humanos , Teste de Materiais , Níquel , Odontometria , Radiografia , Reprodutibilidade dos Testes , Preparo de Canal Radicular/métodos , Titânio , Ápice Dentário/diagnóstico por imagemRESUMO
This study evaluated the effect of different ultrasonic vibration protocols on custom cast post-and-cores' retention to the root canal. Post holes were placed in the root canals of human maxillary canines, and post-and-core sets were luted, using zinc phosphate cement. The samples were divided into 5 groups (n = 8). Group 1 (control) received no ultrasonic vibration. For the other samples, the tip of the ultrasonic device was positioned either over the incisal face of the core (Group 2), over the lateral core surfaces and close to the incisal edge (Group 3), over the lateral face of the core but close to the line of cementation (Group 4), or over the lateral face of the core but with the end of the mouth mirror handle positioned on the opposite surface of the core (Group 5). After a tensile test, data were submitted to 2-way ANOVA and Tukey's tests (P < 0.05). The control group showed higher values than all of the groups that were submitted to ultrasonic vibration. Bond strength was similar for Groups 2 and 3. Bond strength was lower in Groups 4 and 5; no statistical difference was observed between these 2 groups. Based on these results, both positioning the tip of the ultrasonic device near the cement line and placing a mouth mirror handle on the opposite surface of the core, are effective ways to reduce the retention of a cast post-and-core within a root canal.
Assuntos
Colagem Dentária , Retenção em Prótese Dentária , Cavidade Pulpar/patologia , Técnica para Retentor Intrarradicular/instrumentação , Cimentação/métodos , Ligas de Cromo/química , Dente Canino/patologia , Análise do Estresse Dentário/instrumentação , Humanos , Umidade , Teste de Materiais , Preparo de Canal Radicular/instrumentação , Preparo de Canal Radicular/métodos , Estresse Mecânico , Propriedades de Superfície , Resistência à Tração , Fatores de Tempo , Ultrassom , Vibração , Cimento de Fosfato de Zinco/químicaRESUMO
Objetivo: investigar na literatura especializada os protocolos laboratoriais para a remoção de retentores intrarradiculares metálicos usando ultrassom. Revisão de literatura: fontes de catalogação bibliográfica identificadas eletronicamente por Pubmed/Medline (www.pubmed.com.br) e Science direct (www.sciencedirect.com) foram utilizadas. Os termos ?intrarradicular?, ?post removal? e ?ultrasound? foram utilizados na busca, incluindo o período de fevereiro de 2004 até dezembro 2010. Os critérios de seleção dos artigos foram relacionados a: 1) vibração ultrassônica: uso ou não de refrigeração, tempo e modo de aplicação e número de aparelhos utilizados; 2) retentores: intervenção no diâmetro/comprimento do núcleo, agentes de cimentação e tipos de pinos. Foram encontrados 11 artigos que abordaram, pelo menos, uma das variáveis descritas. A partir de informações verificadas nesses estudos, constatou-se que o uso de refrigeração, maior tempo e aplicação intermitente do ultrassom, bem como a utilização de mais de um aparelho foram fatores favoráveis para a remoção dos retentores. Esse procedimento também foi otimizado pelos desgastes do diâmetro/comprimento dos núcleos dos retentores previamente à vibração ultrassônica, principalmente quando foram utilizados os cimentos fosfato de zinco e ionômero de vidro. Na maior parte dos estudos as variáveis foram estudadas isoladamente e não associadas. Conclusões: o uso de ultrassom é um método valioso para a remoção de retentores intrarradiculares. No entanto, novas investigações envolvendo a combinação dos diversos procedimentos da vibração ultrassônica são necessárias, visando aumentar a previsibilidade e a eficácia dessa técnica.
RESUMO
This in vitro study compared different ultrasonic vibration modes for intraradicular cast post removal. The crowns of 24 maxillary canines were removed, the roots were embedded in acrylic resin blocks, and the canals were treated endodontically. The post holes were prepared and root canal impressions were taken with self-cured resin acrylic. After casting, the posts were cemented with zinc phosphate cement. The samples were randomly distributed into 3 groups (n=8): G1: no ultrasonic vibration (control); G2: tip of the ultrasonic device positioned perpendicularly to core surface and close to the incisal edge; and G3: tip of the ultrasonic device positioned perpendicularly to core surface at cervical region, close to the line of cementation. An Enac OE-5 ultrasound unit with an ST-09 tip was used. All samples were submitted to the tensile test using an universal testing machine at a crosshead speed of 1 mm/min. Data were subjected to one-way ANOVA and Tukey's post-hoc tests (α=0.05). Mean values of the load to dislodge the posts (MPa) were: G1 = 4.6 (± 1.4) A; G2 = 2.8 (± 0.9) B, and G3= 0.9 (± 0.3) C. Therefore, the ultrasonic vibration applied with the tip of device close to the core's cervical area showed higher ability to reduce the retention of cast post to root canal.
Assuntos
Descolagem Dentária/instrumentação , Técnica para Retentor Intrarradicular/instrumentação , Ultrassom/instrumentação , Vibração , Cimento de Fosfato de Zinco/química , Análise de Variância , Cimentação , Dente Canino/cirurgia , Análise do Estresse Dentário/métodos , Humanos , Técnicas In Vitro , Tratamento do Canal Radicular/métodosRESUMO
The aim of this study was to assess the influence of surface pretreatments of fiber-reinforced posts on flexural strength (FS), modulus of elasticity (ME) and morphology of these posts, as well as the bond strength (BS) between posts and core material. Fifty-two fiber posts (smooth and serrated) were assigned to 4 groups (n=13): no treatment (control), 10% hydrogen peroxide (HP) for 10 min (HP-10), 24% HP for 1 min (HP-24) and airborne-particle abrasion (Al(2)O(3)). To evaluate FS and ME, a 3-point bending test was performed. Three posts of each group were examined by scanning electron microscopy. Composite resin was used as the core build-up and samples were sectioned to obtain microtensile sticks. Data were analyzed by ANOVA and Tukey's test (α=0.05). For FS, significant differences were observed between posts type and surface pretreatment (p<0.05), with the highest means for the smooth posts. Al2O3 provided higher FS than HP-24. Al(2)O(3) promoted higher ME than HP-24 and control. SEM images revealed partial dissolution of the resin matrix in all treated groups. The smooth posts had higher BS and FS than serrated posts (p<0.05). Mechanical properties of the glass fiber posts and the bond strength between posts and composite material were not altered by the surface treatments, except for airborne-particle abrasion that increased the post elastic modulus.
Assuntos
Colagem Dentária , Corrosão Dentária/métodos , Materiais Dentários/química , Vidro/química , Técnica para Retentor Intrarradicular/instrumentação , Óxido de Alumínio/química , Resinas Compostas/química , Planejamento de Prótese Dentária , Análise do Estresse Dentário/instrumentação , Módulo de Elasticidade , Resinas Epóxi/química , Humanos , Peróxido de Hidrogênio/química , Teste de Materiais , Microscopia Eletrônica de Varredura , Oxidantes/química , Maleabilidade , Silanos/química , Solubilidade , Estresse Mecânico , Propriedades de Superfície , Temperatura , Resistência à Tração , Fatores de Tempo , Água/químicaRESUMO
The aim of this study was to assess the influence of surface pretreatments of fiber-reinforced posts on flexural strength (FS), modulus of elasticity (ME) and morphology of these posts, as well as the bond strength (BS) between posts and core material. Fifty-two fiber posts (smooth and serrated) were assigned to 4 groups (n=13): no treatment (control), 10% hydrogen peroxide (HP) for 10 min (HP-10), 24% HP for 1 min (HP-24) and airborne-particle abrasion (Al2O3). To evaluate FS and ME, a 3-point bending test was performed. Three posts of each group were examined by scanning electron microscopy. Composite resin was used as the core build-up and samples were sectioned to obtain microtensile sticks. Data were analyzed by ANOVA and Tukey's test (α=0.05). For FS, significant differences were observed between posts type and surface pretreatment (p<0.05), with the highest means for the smooth posts. Al2O3 provided higher FS than HP-24. Al2O3 promoted higher ME than HP-24 and control. SEM images revealed partial dissolution of the resin matrix in all treated groups. The smooth posts had higher BS and FS than serrated posts (p<0.05). Mechanical properties of the glass fiber posts and the bond strength between posts and composite material were not altered by the surface treatments, except for airborne-particle abrasion that increased the post elastic modulus.
O objetivo deste estudo foi avaliar a influência do pré-tratamento de superfície dos pinos de fibra de vidro na resistência à flexão (RF), módulo de elasticidade (ME) e morfologia, bem como a resistência de união (RU) entre os pinos e o núcleo de preenchimento. Cinqüenta e dois pinos de fibra de vidro (lisos e serrilhados) foram divididos em 4 grupos (n=13): sem tratamento (controle), peróxido de hidrogênio a 10% por 10 min (HP-10), peróxido de hidrogênio 24% por 1 min (HP-24) e jato de óxido de alumínio (Al2O3). Para avaliar a RF e ME, o ensaio de flexão de 3 pontos foi realizado. Três pinos de cada grupo foram examinados em MEV. Resina composta foi utilizada como núcleo de preenchimento e as amostras foram seccionadas para obter palitos de microtração. Os dados foram analisados por ANOVA e teste de Tukey (α=0,05). Na RF, observou-se diferença estatisticamente significante entre os pinos e tipo de pré-tratamento de superfície (p<0,05), com as maiores médias para os pinos lisos. Al2O3 proporcionou maior RF que HP-24. Al2O3 promoveu maior ME que HP-24 e grupo controle. MEV revelou dissolução parcial da matriz de resina em todos os grupos tratados. Os pinos lisos tiveram a maior RU (p<0,05). Os pinos lisos apresentaram RF e RU superior aos pinos serrilhados (p<0,05). As propriedades mecânicas dos pinos de fibra de vidro e a resistência de união entre os pinos e o material resinoso não foram alterados pelos tratamentos de superfície, com exceção do jato de óxido de alumínio que aumentou o módulo de elasticidade dos pinos.
Assuntos
Humanos , Colagem Dentária , Corrosão Dentária/métodos , Materiais Dentários/química , Vidro/química , Técnica para Retentor Intrarradicular/instrumentação , Óxido de Alumínio/química , Resinas Compostas/química , Planejamento de Prótese Dentária , Análise do Estresse Dentário/instrumentação , Módulo de Elasticidade , Resinas Epóxi/química , Peróxido de Hidrogênio/química , Teste de Materiais , Microscopia Eletrônica de Varredura , Oxidantes/química , Maleabilidade , Solubilidade , Estresse Mecânico , Propriedades de Superfície , Silanos/química , Temperatura , Resistência à Tração , Fatores de Tempo , Água/químicaRESUMO
This in vitro study compared different ultrasonic vibration modes for intraradicular cast post removal. The crowns of 24 maxillary canines were removed, the roots were embedded in acrylic resin blocks, and the canals were treated endodontically. The post holes were prepared and root canal impressions were taken with self-cured resin acrylic. After casting, the posts were cemented with zinc phosphate cement. The samples were randomly distributed into 3 groups (n=8): G1: no ultrasonic vibration (control); G2: tip of the ultrasonic device positioned perpendicularly to core surface and close to the incisal edge; and G3: tip of the ultrasonic device positioned perpendicularly to core surface at cervical region, close to the line of cementation. An Enac OE-5 ultrasound unit with an ST-09 tip was used. All samples were submitted to the tensile test using an universal testing machine at a crosshead speed of 1 mm/min. Data were subjected to one-way ANOVA and Tukey's post-hoc tests (α=0.05). Mean values of the load to dislodge the posts (MPa) were: G1 = 4.6 (± 1.4) A; G2 = 2.8 (± 0.9) B, and G3= 0.9 (± 0.3) C. Therefore, the ultrasonic vibration applied with the tip of device close to the core's cervical area showed higher ability to reduce the retention of cast post to root canal.
Este estudo in vitro comparou diferentes modos de vibração ultra-sônica na remoção de pinos intra-radiculares fundidos. As coroas de 24 caninos superiores foram removidas, as raízes foram incluídas em blocos de resina acrílica e tratadas endodonticamente. Os espaços para os pinos intra-radiculares foram preparados e depois moldados com resina acrílica autopolimerizável. Após a fundição, os pinos intra-radiculares foram cimentados com cimento de fosfato de zinco. As amostras foram distribuídas aleatoriamente em três grupos (n=8): G1: sem vibração ultra-sônica (controle), G2: ponta do aparelho ultra-sônico posicionada perpendicularmente à superfície do núcleo e perto da borda incisal e G3: ponta do aparelho ultra-sônico posicionada perpendicularmente à superfície do núcleo na região cervical, perto da linha de cimentação. Uma unidade de ultra-som Enac OE-5 com uma ponta ST-09 foi usada. Todas as amostras foram submetidas ao teste de tração utilizando máquina universal de ensaios a uma velocidade de 1 mm/min. Os dados foram submetidos aos testes ANOVA e Tukey post-hoc (α = 0,05). Os valores médios de carga para deslocar os pinos (MPa) foram: G1 = 4,6 (± 1,4) A; G2 = 2,8 (± 0,9), B e G3 = 0,9 (± 0,3) C. Portanto, a vibração ultra-sônica aplicada com a ponta do dispositivo perto da zona cervical do núcleo apresentou maior capacidade de reduzir a retenção de pinos metálicos fundidos no canal radicular.
Assuntos
Humanos , Descolagem Dentária/instrumentação , Técnicas In Vitro , Técnica para Retentor Intrarradicular/instrumentação , Ultrassom/instrumentação , Vibração , Cimento de Fosfato de Zinco/química , Análise de Variância , Cimentação , Dente Canino/cirurgia , Análise do Estresse Dentário/métodos , Tratamento do Canal Radicular/métodosRESUMO
Esse estudo avaliou a percepção de adolescentes infratores sobre a convivência familiar e dentro da instituição, sobre a saúde geral e bucal. Foi adotada abordagem qualitativa, com a participação de adolescentes infratores (13 a 17 anos) em processo de ressocialização. Esses adolescentes estavam sendo atendidos em clínica odontológica por alunos de graduação, sob supervisão docente. Após assinatura do termo de consentimento, os adolescentes foram entrevistados, sendo suas falas gravadas, transcritas e submetidas à análise de conteúdo. Para a maioria dos adolescentes, a família foi definida como um espaço de conflitos e distante das suas vidas diárias. Na instituição, eles relataram múltiplas e variadas atividades, esportivas, de arte e educação, que devem ser cumpridas em horários rígidos. Todos falaram, em algum momento da entrevista, sobre a recompensa com diferentes "benefícios", pelo bom comportamento dentro da instituição, sendo a liberdade o mais desejado por todos. A saúde foi definida como: emprego, acesso a programas educativos, acesso a cuidados médicos e de enfermagem e participação nos cursos oferecidos na instituição. Aspectos pessoais de autocuidado, como uma boa alimentação, a prática de esportes e a higiene do corpo foram também citados como determinantes da saúde. Para alguns deles, saúde é liberdade, abandono das drogas e do crime. A saúde bucal foi definida como higiene bucal por todos os adolescentes (AU).
This study evaluated the perception of delinquent adolescents toward family, the correctional institution they attended, and oral and general health. We adopted a qualitative approach with the participation of adolescents (age 1317) in the process of re-socialization. The adolescents were being treated in a dental clinic by undergraduate students under supervision. After signing a consent form, the adolescents were interviewed and their statements were recorded, transcribed and submitted to content analysis. For most adolescents, family was defined as an area of conflict and remote from their daily lives. As for their correctional institution, they reported that it offered several different activities, sports, art and education, all of which had to be completed according to a rigorous schedule. At some point in the interview, all mentioned the reward gained from different "benefits" for good behavior within the institution, and the greater freedom desired by all. Health was defined as employment, access to educational programs, access to medical care and nursing, and participation in courses offered at the institution. Personal aspects of self-care, such as a good food, sports practice and body hygiene, were also mentioned as determinants of health. To some, health meant freedom, abandonment of drugs and of crime. Oral health was defined by all adolescents as oral hygiene (AU).
Assuntos
Humanos , Masculino , Feminino , Adolescente , Adolescente , Assistência Odontológica , Serviços de Saúde , Saúde Bucal , Brasil , Estudos de Avaliação como Assunto/métodos , Fatores Socioeconômicos , Inquéritos e QuestionáriosRESUMO
OBJECTIVE: The aim of this study was to evaluate the effect of simulated periodontal ligament (SPDL) on custom cast dowel and core removal by ultrasonic vibration. MATERIAL AND METHODS: Thirty-two human maxillary canines were included in resin cylinders with or without SPDL made from polyether impression material. In order to allow tensile testing, the roots included in resin cylinders with SPDL were fixed to cylinders with two stainless steel wires. Post-holes were prepared by standardizing the length at 8 mm and root canal impressions were made with self-cured resin acrylic. Cast dowel and core sets were fabricated and luted with Panavia F resin cement. Half of the samples were submitted to ultrasonic vibration before the tensile test. Data were analyzed statistically by two-way ANOVA and Tukey's post-hoc tests (p<0.05). RESULTS: The ultrasonic vibration reduced the tensile strength of the samples directly included in resin cylinders. There was no difference between the values, whether or not ultrasonic vibration was used, when the PDL was simulated. However, the presence of SPDL affected the tensile strength values even when no ultrasonic vibration was applied. CONCLUSION: Simulation of PDL has an effect on both ultrasonic vibration and tensile testing.
Assuntos
Instrumentos Odontológicos , Remoção de Dispositivo/instrumentação , Ligamento Periodontal , Técnica para Retentor Intrarradicular/instrumentação , Análise de Variância , Dente Canino , Humanos , Teste de Materiais , Cimentos de Resina , Preparo de Canal Radicular , Resistência à Tração , Ultrassom , VibraçãoRESUMO
ABSTRACT OBJECTIVE: The aim of this study was to evaluate the effect of simulated periodontal ligament (SPDL) on custom cast dowel and core removal by ultrasonic vibration. MATERIAL AND METHODS: Thirty-two human maxillary canines were included in resin cylinders with or without SPDL made from polyether impression material. In order to allow tensile testing, the roots included in resin cylinders with SPDL were fixed to cylinders with two stainless steel wires. Post-holes were prepared by standardizing the length at 8 mm and root canal impressions were made with self-cured resin acrylic. Cast dowel and core sets were fabricated and luted with Panavia F resin cement. Half of the samples were submitted to ultrasonic vibration before the tensile test. Data were analyzed statistically by two-way ANOVA and Tukey's post-hoc tests (p<0.05). RESULTS: The ultrasonic vibration reduced the tensile strength of the samples directly included in resin cylinders. There was no difference between the values, whether or not ultrasonic vibration was used, when the PDL was simulated. However, the presence of SPDL affected the tensile strength values even when no ultrasonic vibration was applied. CONCLUSION: Simulation of PDL has an effect on both ultrasonic vibration and tensile testing.
Assuntos
Humanos , Instrumentos Odontológicos , Remoção de Dispositivo/instrumentação , Ligamento Periodontal , Técnica para Retentor Intrarradicular/instrumentação , Análise de Variância , Dente Canino , Teste de Materiais , Cimentos de Resina , Preparo de Canal Radicular , Resistência à Tração , Ultrassom , VibraçãoRESUMO
This study sought to evaluate how ultrasound affected the removal of stainless steel and titanium posts that had been attached with two different resin cements. The crowns of 32 maxillary canines were removed, the roots were embedded in acrylic resin blocks, and the canals were treated endodontically. The specimens were randomly distributed into two groups (n = 16) according to the brand of cement and subdivided (n = 8) according to the type of post. The specimens were submitted to ultrasonic vibration applied perpendicularly to the long axis of the tooth for 60 seconds. Data were submitted to ANOVA and showed no significant statistical difference among the groups (p > 0.05). It may be concluded that the effects of ultrasonic vibration used to remove intraradicular posts were not significantly different when applied to stainless steel or titanium posts cemented with chemically or dual-activated resin cements.
Assuntos
Remoção de Dispositivo , Técnica para Retentor Intrarradicular/instrumentação , Ultrassom , Condicionamento Ácido do Dente , Compostos de Boro/química , Cimentação/métodos , Dente Canino/anatomia & histologia , Ligas Dentárias/química , Materiais Dentários/química , Cavidade Pulpar/anatomia & histologia , Análise do Estresse Dentário/instrumentação , Humanos , Teste de Materiais , Metacrilatos/química , Metilmetacrilatos/química , Ácidos Fosfóricos/química , Cimentos de Resina/química , Preparo de Canal Radicular/métodos , Aço Inoxidável/química , Estresse Mecânico , Temperatura , Fatores de Tempo , Titânio/química , Vibração , Água/químicaRESUMO
OBJECTIVE: This in vitro study evaluated the influence of luting agents on ultrasonic vibration time for intraradicular cast post removal. MATERIAL AND METHODS: After endodontic treatment, 30 roots of extracted human canines were embedded in resin cylinders. The post-holes were prepared at 10 mm depth and their impressions were taken using autopolymerizing acrylic resin. After casting procedures using a nickel-chromium alloy, the posts were randomly distributed into 3 groups (n=10) according to the luting material: G1- zinc phosphate (SS White) (control group), G2 - glass ionomer cement (Vidrion C; SS White), and G3- resin cement (C&B; Bisco). In G3, the adhesive procedure was performed before post cementation. After 24 h, the cement line was removed at the post/tooth interface using a fine diamond bur, and the ST-09 tip of an Enac ultrasound unit was applied at maximum power on all surfaces surrounding the posts. The application time was recorded with a chronometer until the post was completely dislodged and data were analyzed by ANOVA and Tukey's test (p<0.05). RESULTS: The roots were removed from the acrylic resin and inspected to detect cracks and/or fractures. The means for G1, G2, and G3 were 168.5, 59.5, and 285 s, respectively, with statistically significant differences among them. Two G3 posts resisted removal, one of which developed a vertical fracture line. CONCLUSIONS: Therefore, the cement type had a direct influence on the time required for ultrasonic post removal. Compared to the zinc phosphate and glass ionomer cements, the resin cement required a longer ultrasonic vibration time.
Assuntos
Humanos , Descolagem Dentária , Cimentos de Ionômeros de Vidro , Técnica para Retentor Intrarradicular , Cimentos de Resina , Cimento de Fosfato de Zinco , Ligas de Cromo , Dente Canino , Análise do Estresse Dentário , Descolagem Dentária/métodos , Teste de Materiais , Fatores de Tempo , Ultrassom , VibraçãoRESUMO
OBJECTIVE: This in vitro study evaluated the influence of luting agents on ultrasonic vibration time for intraradicular cast post removal. MATERIAL AND METHODS: After endodontic treatment, 30 roots of extracted human canines were embedded in resin cylinders. The post-holes were prepared at 10 mm depth and their impressions were taken using autopolymerizing acrylic resin. After casting procedures using a nickel-chromium alloy, the posts were randomly distributed into 3 groups (n=10) according to the luting material: G1- zinc phosphate (SS White) (control group), G2 - glass ionomer cement (Vidrion C; SS White), and G3- resin cement (C & B; Bisco). In G3, the adhesive procedure was performed before post cementation. After 24 h, the cement line was removed at the post/tooth interface using a fine diamond bur, and the ST-09 tip of an Enac ultrasound unit was applied at maximum power on all surfaces surrounding the posts. The application time was recorded with a chronometer until the post was completely dislodged and data were analyzed by ANOVA and Tukey's test (p<0.05). RESULTS: The roots were removed from the acrylic resin and inspected to detect cracks and/or fractures. The means for G1, G2, and G3 were 168.5, 59.5, and 285 s, respectively, with statistically significant differences among them. Two G3 posts resisted removal, one of which developed a vertical fracture line. CONCLUSIONS: Therefore, the cement type had a direct influence on the time required for ultrasonic post removal. Compared to the zinc phosphate and glass ionomer cements, the resin cement required a longer ultrasonic vibration time.
Assuntos
Descolagem Dentária , Cimentos de Ionômeros de Vidro , Técnica para Retentor Intrarradicular , Cimentos de Resina , Cimento de Fosfato de Zinco , Ligas de Cromo , Dente Canino , Descolagem Dentária/métodos , Análise do Estresse Dentário , Humanos , Teste de Materiais , Fatores de Tempo , Ultrassom , VibraçãoRESUMO
Neste estudo in vitro avaliou-se a influência dos desgastes do núcleo e da linha de cimento na remoção ultra-sônica de retentores intra-radiculares metálicos fundidos. Foram utilizados vinte e quatro pré-molares humanos, unirradiculares, que tiveram suas coroas removidas mantendo um remanescente radicular de 15mm. Os canais radiculares foram tratados endodonticamente, sendo preparados espaços para pinos com 9mm de profundidade, que foram moldados para obtenção dos retentores. Após fundição, os pinos foram cimentados com fosfato de zinco (SS White) e o conjunto raiz/pino fixado em tubos de PVC com 0,5 polegada de diâmetro e 3 cm de altura, contendo resina autopolimerizável. Decorridos 7 dias, a amostra foi distribuída aleatoriamente em 2 grupos (n=12): G1- desgastes dos núcleos e linha de cimento + ultra-som, e G2-apenas ultra-som. No G1 realizou-se os desgastes com a broca #1557, circunferencialmente aos núcleos e em seguida na linha cervical do cimento, com uma ponta diamantada cônica #3203 (KG Sorensen), numa profundidade de 2mm. O aparelho Enac (Osada, Japão) em potência máxima, com a ponta ST 09, foi aplicado em todas as faces dos núcleos, registrando-se o tempo até o completo deslocamento dos pinos. Para análise estatística utilizou-se o teste t-Student (p<0,05). Verificou-se que a média de tempo para G1 e G2 foi de 48,4 e 99,4 segundos, respectivamente, com diferença significatica entre os grupos (p=0,036). Portanto, os desgastes do núcleo e da linha de cimento diminuíram, de forma significativa, o tempo de vibração ultra-sônica na remoção de retentores intra-radiculares cimentados com fosfato de zinco.
Assuntos
Técnica para Retentor Intrarradicular , Dente não Vital , Compômeros , Interpretação Estatística de Dados , Pinos DentáriosRESUMO
This study evaluated the strength required to remove glass-fiber and metallic cast posts with different lengths. Sixty endodontically treated canines were included and their roots were embedded in acrylic resin after discarding the crowns. Samples were randomly assigned to 3 groups according to the post length (n = 20): I- 6 mm, II - 8 mm and III- 10 mm. Each group was divided into 2 subgroups based on the post material (n = 10): A- glass fiber or B- metallic cast. Post-space was prepared with Fibrekor Post Kit attached to a parallelometer. In subgroup A, prefabricated glass fiber posts from Fibrekor Post Kit were utilized. In metallic post group (subgroup B), an impression of post space was obtained, followed by casting. All posts were luted with Panavia F cement. A universal testing machine determined the force required to dislodge each post. ANOVA analysis indicated significant differences (P < 0.01) among post length. Tukey test showed that posts with 10 mm-length showed higher resistance on removal than posts with 6 mm-length. Posts with 8 mm-length did not exhibit difference when compared to 6 and 10 mm posts. No significant differences (P > 0.05) were observed between the tested post materials. It was concluded that the type of post did not influence the removal resistance and that posts with 10 mm-length required greater force to be dislodged.
Assuntos
Colagem Dentária/métodos , Remoção de Dispositivo , Técnica para Retentor Intrarradicular , Alumínio , Análise de Variância , Cimentação/métodos , Resinas Compostas , Cobre , Dente Canino , Ligas Dentárias , Planejamento de Prótese Dentária , Análise do Estresse Dentário , Humanos , Teste de Materiais , Cimentos de Resina , Estatísticas não Paramétricas , Resistência à TraçãoRESUMO
The efficacy of ultrasound in removing cast metal posts was evaluated in this in vitro study using one or two ultrasound units and ultrasonic vibration for various lengths of time. The crowns of 30 healthy maxillary canines were removed, the roots were embedded in acrylic resin blocks, and the root canals were treated endodontically. The canals were prepared and their impressions were taken with self-curing acrylic resin. After casting with copper-aluminum alloy, the posts were blasted with aluminum oxide and cemented with Panavia F resin cement. The specimens were divided into five groups. In groups I and II, only one ultrasound unit was used for 30 and 60 s, respectively; in groups III and IV, two ultrasound units were used simultaneously for 30 and 60 s, respectively; in group V, ultrasound was not used (control). Ultrasonic vibrations were applied with an Enac OE-5 ultrasound unit and an ST-09 tip. All samples were subjected to traction on an Instron machine (model 4444) at a cross-head speed of 1 mm/min. Analysis of the results revealed a statistically significant difference between the groups (ANOVA, P < 0.01); however the difference between groups II and IV was not statistically significant. The efficacy of ultrasound in removing intraradicular posts was confirmed, and the most effective technique was the use of two ultrasound units, independent of the length of time ultrasound was applied.