Os primeiros passos para a implementação de um banco de dentes humanos na Faculdade de Odontologia UFF / The first steps to implement a human teeth bank at Faculty of Dentistry - UFF

O Banco de Dentes Humanos (BDH) é uma instituição sem fins lucrativos, vinculada a uma faculdade, universidade ou instituição com o propósito de suprir as necessidades acadêmicas, através do fornecimento de dentes humanos para estudo e treinamento laboratorial dos alunos dos cursos de graduação e pós-graduação. Assim, o presente trabalho teve como objetivo relatar os métodos utilizados para captação, tratamento, seleção, preservação, armazenamento e reutilização de dentes humanos extraídos, realizados por alunos da Faculdade de Odontologia (FO) da Universidade Federal Fluminense (UFF) através de dois projetos deferidos junto a PROAES-UFF. Para isso, foram realizadas campanhas de conscientização e programas de divulgação para a doação de dentes humanos extraídos permanentes e decíduos tanto para a comunidade científica odontológica como para a comunidade leiga. Após 24 meses, foram captados um total de 2.536 dentes, sendo 346 molares superiores, 279 molares inferiores, 262 pré-molares superiores, 418 pré-molares inferiores, 343 caninos, 296 incisivos superiores e 592 incisivos inferiores. As campanhas e ações dos projetos da PROAES-UFF foram eficientes para coletar dentes humanos, suprindo as atividades laboratoriais de diversas disciplinas na graduação e também servindo de estoque para a futura implementação do BDH da FO-UFF.

The Human Teeth Bank (HTB) is a non-profit institution, linked to a college, university or institution with the purpose of meeting academic needs, through the provision of human teeth for study and laboratory training of undergraduate and postgraduate students. Thus, this study aimed to report the methods of capture, treatment, selection, preservation, storage and reuse of extracted human teeth, carried out by students from the Faculty of Dentistry (FO) of Universidade Federal Fluminense (UFF) through two projects approved by PROAES-UFF. To this end, awareness campaigns and outreach programs were carried out for the donation of human teeth extracted, permanent and deciduous, both for the dental scientific community and for the lay community. After 24 months, a total of 2,536 teeth were captured, with 346 upper molars, 279 lower molars, 262 upper premolars, 418 lower premolars, 343 canines, 296 upper incisors and 592 lower incisors. The campaigns and actions of PROAES-UFF projects were efficient in collecting human teeth, supplying the laboratory activities of several disciplines during graduation and also serving as a stock for a future implementation of the HTB of FO-UFF.

Uso de dientes bovinos como elección para trabajos de investigación en odontología / The use of bovine teeth as a choice for dental investigation papers

Los dientes animales de las diferentes especies (hu- mano, equino, cerdo, etc.) están constituidos histológi- camente por cuatro tejidos fundamentales. Ellos son: esmalte, dentina, cemento y pulpa dental. Su compo- sición, estructura, morfología y tamaño son disímiles para cada género. Según numerosas investigaciones, los dientes de bovino serían los de elección por ser de fácil obtención y por tener muy pocas, o ninguna, diferencias tanto a nivel macro como microscópico con respecto a los dientes humanos. El objetivo de la presente revisión es aportar información actualizada acerca de las características histológicas de los tejidos dentarios bovinos y profundizar el conocimiento de las similitudes y diferencias de los dientes bovinos y humanos dando soporte a otros estudios compa- rativos y promoviendo la utilización de las piezas dentarias bovinas en trabajos de investigación en odontología (AU)

The animal teeth of the different species (human, equine, pig, etc.) are histologically constituted by four fundamental tissues: enamel, dentin, cement and dental pulp. Their composition, structure, morphology and size are dissimilar for each gender. According to numerous investigations, bovine teeth would be the ones of choice because they are easy to obtain and have very few or no differences, both at the macro and microscopic levels, with respect to human teeth. The objective of this review is to provide updated information about the histological characteristics of bovine dental tissues and deepen the knowledge of the similarities and differences between bovine and human teeth, supporting other comparative studies and promoting the use of bovine dental pieces in research work in dentistry (AU)

Evaluation of the coefficient of thermal expansion of human and bovine dentin by thermomechanical analysis

The mismatch of thermal expansion and contraction between restorative materials and tooth may cause stresses at their interface, which may lead to microleakage. The present work compared the coefficient of thermal expansion (CTE) with the thermomechanical behavior of human and bovine teeth and determined if the CTE is a suitable parameter to describe tooth behavior. Fifteen human third molar and 15 bovine incisor tooth slices (6×5×2 mm) were allocated to 3 groups according to the test environment: G1 - room condition, G2 - 100 percent humidity, G3 - desiccated and tested in dry condition. Each specimen was weighed, heated from 20 to 70ºC at 10ºC min−1 and reweighed. The CTE was measured between 20 and 50ºC. Fresh dentin (human -0.49 percent ± 0.27, bovine -0.22 percent ± 0.16) contracted on heating under dry condition. Under wet conditions, only human teeth (-0.05 percent ± 0.04) showed contraction (bovine 0.00 percent ± 0.03) accompanied by a significantly lower (p<0.05) weight loss than in dry specimens (human 0.35 percent ± 0.15, bovine 0.45 percent ± 0.20). The desiccated dentin expanded on heating without obvious weight changes (0.00 percent ± 0.00). The CTE found was, respectively, in dry, wet and dissected conditions in ºC-1: human (-66.03×10-6, -6.82×10-6, 5.52×10-6) and bovine (-33.71×10-6, 5.47×10-6, 4.31×10-6). According to its wet condition, the dentin showed different CTEs. The thermal expansion behavior of human and bovine dentin was similar. A simple evaluation of the thermal expansion behavior of tooth structure by its CTE value may not be appropriate as a meaningful consideration of the effects on the tooth-material interface.

A discrepância entre a expansão e a contração térmica dos materiais restauradores e o dente podem causar estresse na sua interface, podendo levar a uma microinfiltração. O presente trabalho determinou e comparou o coeficiente de expansão térmica (CET) com o comportamento termo mecânico dos dentes humanos e bovinos e determinou se o CET é um parâmetro adequado para descrever o comportamento dental. 15 fatias (6×5×2 mm) de terceiros molares humanos e 15 de incisivos bovinos foram divididos em 3 grupos de acordo com o ambiente testado: G1 - condição ambiente, G2 - 100 por cento de umidade, G3 - dissecado e testado em condição seca. Cada espécime foi pesado, aquecido de 20 a 70C a 10ºC min-1 e pesados novamente. O CET foi mensurado entre 20 e 50ºC. Dentina fresca (humana -0,49 por cento ± 0,27, bovina -0,22 por cento ± 0,16) contrai no aquecimento sobre condição seca. Em condição úmida, somente dente humano (-0,05 por cento ± 0,04) mostrou contração (bovina 0,00 por cento ± 0,03) acompanhado por uma significante (p<0.05) perda de massa que os espécimes secos. A dentina dissecada expande no aquecimento sem mudanças óbvias de peso (0,00 por cento ± 0,00). O CET encontrado foi, respectivamente, em condições seca, úmida e dissecada em ºC-1: humana (-66,03×10-6, -6,82×10-6, 5,52×10-6) e bovina (-33,71×10-6, 5,47×10-6, 4,31×10-6). De acordo com sua condição de umidade, a dentina mostrou diferentes CETs. O comportamento de expansão térmica de dentes humanos e bovinos é similar. Uma simples avaliação do coeficiente de expansão térmica da estrutura dental pelo seu valor de CET pode não ser apropriada para uma consideração significativa dos efeitos na interface dente-material restaurador.

Uso de dientes humanos en la enseñanza odontológica: aspectos éticos, legales y de bioseguridad / Use of human teeth in dental education: ethical, legal and biosafety

El uso de dientes naturales en el proceso de enseñanza-aprendizaje de Odontología es fundamental, además los nuevos planes curriculares vigentes en la mayoría de instituciones de enseñanza brasileras de nivel superior dan privilegio a la investigación. Es de fundamental relevancia conocer tanto la procedencia y formas de uso de los dientes humanos extraídos, como los procedimientos de descontaminación y almacenamiento empleados para este fin. El presente trabajo tiene como objetivo analizar la forma de uso de dientes humanos en la enseñanza odontológica en la Facultad de Odontología de la Universidad Federal de Juiz de Fora a partir de la aplicación de 200 cuestionarios a los alumnos de primero a séptimo periodo de formación. Los resultados demuestran que todavía existe una despreocupación en lo que se refiere a los aspectos ético-legales y de bioseguridad en la obtención y manipulación de dientes humanos por parte de los alumnos. Los datos demuestran la relevancia de la funcionalidad del Banco de Dientes Humanos encargada de abastecer de dientes a los académicos, profesores e investigadores, de forma ética y legal dentro de los estándares de bioseguridad, favoreciendo al menor riesgo de contaminación cruzada.

The use of natural teeth in the dental education and research is essential, moreover, the new curriculum model currently in the majority of Brazilian institutions of higher education focuses on research practice. Besides the importance of knowing the origin and ways of using extracted human teeth, another relevant question is whether the procedures for decontamination and storage are being employed. This study aimed to investigate the use of human teeth in dental education in College of Dentistry of Federal University of Juiz de Fora by application of 200 questionnaires to students between 10 and 70 periods. Given the above study, it appears that there is still a lack of concern with the ethical-legal and bio-security in obtaining and handling human teeth by students. Data show the relevance of the functionality of the Human Teeth Bank, with the role of providing teeth to academics, teachers and researchers in an ethical, legal and standards of biosecurity, providing less risk of cross contamination.

Trace elemental analysis of dental caries in human teeth by external pixe.

The elemental profiles of the dental caries in human teeth were analyzed by the external proton induced X-ray emission (External PIXE) studies. A total of ten elements including trace namely P, Ca, V, Mn, Fe, Cu, Zn, As, Sr and Pb were estimated in the present study. P and Ca were found to be the major elements whereas all other elements were in trace level. It was observed that the concentration of elements Phosphorus and Calcium varied between the range 7.98% and 19.26% and 19.83% and 35.2% respectively in dental caries.

Fracture strength of composite fixed partial denture using bovine teeth as a substitute for human teeth with or without fiber-reinforcement

This study evaluate the use of bovine teeth as a substitute for human teeth on fracture strength tests of composite fixed partial dentures (Cpd), with and without fiberglass reinforcement (Fg). Eighty teeth were selected, being 40 bovine incisors, 20 human premolars and 20 molars. Bovine incisors were ground to get a platform, simulating an occlusal surface of human molar. Teeth in pairs were embedded in polystyrene resin, simulating the periodontal ligament and divided in 4 groups: B-Cpd-Fg: bovine teeth restored with Cpd with Fg; B-Cpd-NFg: bovine teeth restored with Cpd without Fg; H-Cpd-Fg: human teeth restored Cpd with Fg; and H-Cpd-NFg: human teeth restored with Cpd without Fg. The Cpd were adhesively fixed and submitted to an axial compression load at the pontic center with a crosshead speed of 0.5 mm/min until fracture. Failure modes were assessed and classified. Data were subjected to two-way ANOVA and Tukey's HSD test (?=0.05). The tooth type had no influence on fracture strength and fracture mode. The inclusion of fiberglass increased significantly the fracture strength. The failure modes were more reparable in groups with fiber-reinforcement. Bovine teeth can be used as a substitute for human teeth in these types of fracture strength tests.

Este estudo avaliou a utilização de dentes bovinos como substituto de dentes humanos em testes de resistência à fratura de próteses adesivas de resina composta (Cpd), com e sem fibra de reforço. Oitenta dentes foram selecionados sendo 40 incisivos bovinos, 20 pré-molares humanos e 20 molares. Incisivos bovinos foram desgastados para obter plataforma, simulando superfície oclusal de molares humanos. Dentes em pares foram incluídos em resina de poliestireno, simulando o ligamento periodontal. As amostras foram divididas em 4 grupos: B-Cpd-Fg, dentes bovinos restaurados com reforço de fibra de vidro, Fg; B-Cpd-NFg, dentes bovinos restaurados com Cpd sem Fg; H-Cpd-Fg, dentes humanos restaurados com Cpd Fg e H-Cpd-NFg, dentes humanos restaurados com Cpd sem Fg. O Cpd foi fixado adesivamente e submetido a carga de compressão axial no centro do pôntico com velocidade de 0,5 mm/min até a fratura. Padrões de fratura foram classificados. Os dados foram submetidos ANOVA fatorial e teste de Tukey HSD (?=0,05). O tipo de dente não teve nenhuma influência na resistência à fratura e modo de fratura. A inclusão de fibra de vidro aumentou significativamente a resistência à fratura. Os padrões de fratura foram mais reparáveis nos grupos com fibra de reforço. Os dentes bovinos podem ser usados como substituto para dentes humanos nesses tipos de testes de resistência à fratura.

Viability of using enamel and dentin from bovine origin as a substitute for human counterparts in an intraoral erosion model

This study ascertained whether under dental erosion models that closely mimics the real-life situation enamel and root dentin from bovine origin would be reliable substitutes for human counterparts. Through a 2x2 crossover design, in a first trial, 14 volunteers wore a palatal device containing slabs of bovine and human enamel. Half of the participants ingested (4x daily, for 10 days) orange juice first, crossing over to mineral water, while the remainder received the reverse sequence. In a second trial, volunteers wore devices with slabs of bovine and human root dentin. Except for the duration of each intraoral phase, which lasted 2 rather 10 days, the experiment with root dentin run exactly as for enamel. Dental substrates were analyzed for surface microhardness. Two-way ANOVAs (α=0.05) indicated no difference between the microhardness values recorded for human and bovine enamel (p=0.1350), but bovine root dentin had lower microhardness compared to its human counterpart (p=0.0432). While bovine enamel can reliably substitute its human counterpart in in situ dental erosion models, bovine root dentin does not seem to be a viable alternative to the corresponding human tissue.

Este estudo visou avaliar, sob um modelo de erosão dental que se aproxima da realidade clínica, se o esmalte e a dentina radicular bovinos seriam substitutos viáveis aos correspondentes substratos de origem humana. De acordo com um delineamento crossover 2x2, 14 voluntários utilizaram dispositivos palatinos contendo fragmentos de esmalte humano e bovino. Metade dos participantes ingeriu suco de laranja (4x/dia, por 10 dias) e, a seguir, alternou para a ingestão de água mineral, enquanto os demais voluntários receberam a seqüência reversa. Em um segundo experimento, os sujeitos da pesquisa fizeram uso do dispositivo palatino contendo fragmentos de dentina radicular bovina e humana. Exceto pela duração de cada uma das duas fases experimentais (2 ao invés de 10 dias), utilizou-se o mesmo protocolo empregado no estudo em que se comparou o esmalte. Os substratos dentais foram avaliados quanto a sua microdureza superficial. ANOVAs a dois critérios (α=0,05) não indicaram diferença entre os valores de microdureza observados para o esmalte humano e bovino (p=0,1350), porém a dentina radicular apresentou microdureza inferior à humana (p=0,0432). Enquanto o esmalte bovino é um substituto fidedigno do substrato humano em modelos in situ de erosão dental, a dentina radicular bovina não parece ser uma alternativa viável ao tecido humano correspondente.

Influence of human and bovine substrate on the microleakage of two adhesive systems

The aim of this study was to evaluate in vitro the marginal sealing of two adhesive systems and to analyze the influence of human and bovine substrates on marginal microleakage in enamel. Rectangular-shaped class V cavities (4 mm wide x 2 mm high x 2 mm deep) were made as follows: 8 cavities were prepared on the buccal and lingual surfaces of the human teeth with margins located on enamel and 16 cavities were prepared on the buccal surfaces of the bovine teeth. The cavities were randomly assigned to 4 groups of 8 cavities according to the adhesive system and substrate: G1 - Prime & Bond 2.1 (Dentsply)/human substrate; G2 - Adhese (Ivoclar/Vivadent)/human substrate; G3 - Prime & Bond 2.1 (Dentsply)/bovine substrate; G4 - Adhese (Ivoclar/Vivadent)/bovine substrate. The cavities were filled with microhybrid composite resin (Fillmagic) and after polishing/finishing procedures, the teeth were subjected to a thermocycling regimen of 500 cycles with 1-min immersions in water at 55° ±2°C and 5° ± 2°C. Next, the teeth were coated with two layers of nail polish to within 1 mm of the margin, submerged in a 50 percent silver nitrate solution for 2 h, rinsed thoroughly in running tap and immersed in developing solution for 8 h. The restorations were bisected resulting in 16 specimens. Microleakage was observed under a stereomicroscope at x25 and recorded using four-point (0-3) scoring system. The data were analyzed statistically by the Mann Whitney U-test at 5 percent significance level. Leakage was present in all specimens and there was statistically significant difference between the adhesive systems. Adhese self-etching system showed significantly more leakage in both substrates (human - p= 0.0001 and bovine - p= 0.0031). There was no statistically significant difference between human and bovine substrates for either of the adhesive systems based on different bonding mechanisms (Prime & Bond 2.1 - p= 0.6923 and Adhese - p= 0.6109). Neither of the...

Banco de dentes humanos para o ensino e pesquisa em Odontologia / Human teeth bank for education and research in Dentistry

O uso de dentes humanos para o ensino e pesquisa em Odontologia é uma prática freqüente. A implantação de Bancos de Dentes Humanos (BDH) em instituições de ensino é fundamental para viabilizar a manipulação segura para aprendizagem, pesquisa e inovações tecnológicas que façam uso de dentes humanos. Para que seu funcionamento seja adequado, a organização e a legalização do uso de dentes devem ser divulgadas. Procedimentos relativos às etapas de arrecadação, limpeza e desinfecção, separação e armazenamento, cessão e/ou empréstimo e de biossegurança devem ser desenvolvidos, aprimorados e colocados ao alcance dos interessados. Este artigo tem como objetivo fazer um levantamento do número de BDH em instituições de ensino de Odontologia do Estado do Rio Grande do Sul e buscar na literatura orientações disponíveis sobre os aspectos práticos, legais, técnicos e científicos necessários ao seu funcionamento em instituições de ensino e pesquisa em Odontologia.

The use of human teeth for teaching/education and research in dentistry is a common practice. The establishment of Human Teeth Bank (BDH) in institutions of education is essential to enable the safe handling in teaching, research and the discovery of new technologies which make use of human teeth. Before BDH establishment is appropriate, its organization and legalization must be disclosed. Procedures of collection, cleaning and disinfection, separation and storage, disposal and/or loan and biosecurity should be developed and improved. The aim of this study is to search the number of BDH inside schools of Dentistry units at Rio Grande do Sul state and to review the literature about the importance of BDH in institutions of education and research as well as its legal, technical and scientific aspects.

Avaliação da microdureza superficial do esmalte e da dentina de dentes bovinos e humanos (permanentes e decíduos) / Surface microhardness evaluation of enamel and dentin in bovine and human teeth (permanent and deciduous)

O objetivo desse estudo foi testar a microdureza superficial do esmalte (E) e da dentina (D) em molares humanos decíduos (grupo d), molares humanos permanentes (grupo p) e incisivos bovinos (grupo b). Foram selecionados 4 espécimes de cada tipo de dente os quais foram mantidos em solução salina até o teste. Os espécimes foram incluídos em uma matriz com resina e polidos com papel metalográfico (até granulação 600) para planificar o esmalte. O teste de dureza Knoop foi realizado em um microdurômetro com carga de 200 g, sendo realizadas 5 leituras (10 s de endentação) por dente. Os espécimes foram novamente submetidos ao polimento para expor dentina (próxima ao LAD), sendo novas leituras realizadas. Os dados foram submetidos à análise estatística (testes ANOVA e Tukey). Os valores médios de dureza (kg/mm2) e desvio padrão foram os seguintes: Ed 338 ± 30,1; Ep 341 ± 32,8; Eb 326 ± 25,5; Dd 104 ± 9,7; Dp 93,3 ± 8,7; Db 91,2 ± 7,3. A dureza do esmalte foi maior que a da dentina nos três tipos de dentes (p < 0,001). Considerando o tipo de substrato, não houve diferenças estatísticas, ou seja, os valores de dureza para esmalte ou dentina foram similares para dentes humanos decíduos e permanentes e dentes bovinos.

The objective of this study was to evaluate the surface microhardness of enamel (E) and dentin (D) from human deciduous molar teeth (Group d), human permanent molar teeth (Group p) and bovine incisor teeth (Group b). Four specimens were selected for each group and stored in saline solution until testing. The specimens were embedded into a resin matrix and polished to 600 grit SiC paper creating a flat enamel surface. The Knoop hardness test was performed in a microhardness device, using a 200 g load. Five measurements were made in each specimen. After that, specimens were polished to expose dentin (near to dentinenamel junction), and other five microhardness measurements were performed per specimen. The values were calculated and statistically analyzed (ANOVA and Tukey tests). Mean hardness values (kg/mm2) and standard deviations were as follows: Ed 338 ± 30.1; Ep 341 ± 32.8; Eb 326 ± 25.5; Dd 104 ± 9.7; Dp 93.3 ± 8.7; Db 91.2 ± 7.3. The microhardness in enamel (E) was statistically higher than in dentin (D) for the three type of teeth studied (p < 0.001). Considering the type of substrate, there were no statistical differences, meaning that the mean hardness values for either enamel or dentin were not different for the human deciduous teeth, human permanent and bovine teeth.

Histomorfologia do reparo após tratamento endodôntico em dentes com rizogênese incompleta: revisão de literatura / Healing process after root canal therapy in immature human teeth: bibliographycal review

O objetivo deste trabalho foi realizar uma revisão bibliográfica sobre a histomorfologia do reparo de dentes com rizogênese incompleta que receberam tratamento endodôntico. Embora o mecanismo histológico do reparo ainda permaneça relativamente obscuro e sua explicação encontre controvérsia na literatura, há o consenso de que a barreira de tecido duro apical pode ser formada por dentina ou cemento, em dependência das células que estiverem presentes no momento da intervenção. A morfologia do reparo da região apical tem sido estudada e caracterizada de duas formas: pelo aparecimento de substância radiopaca que obstrui a abertura apical simplesmente ou pela complementação do desenvolvimento radicular com deposição de tecido duro apical, podendo a raiz do elemento dentário apresentar diversas configurações. O hidróxido de cálcio continua sendo o material mais requisitado nesse tipo de tratamento, mesmo que alguns pesquisadores sustentem que o fechamento apical ocorra quando controlada a infecção e sem a utilização de um material indutor de tecido mineralizado

This bibliographical research has investigated the healing process after root canal therapy in immature human teeth. Although there is still uncertainty about the histological mechanism of the treatment and there is a controversial explanation in literature, the authors asseverate that the apical limit can be formed by two tissues: dentine or cementum. The healing process has been studied and characterized by the appearance of radiopaque tissue on the apical region or by the complementation of radicular development with hard apical tissue deposition. In this case the root of the teeth may present several forms. The most commonly used substance in the treatment is calcium hydroxide. Some researchers say that the apical closure may occur when the infection is controlled and in the absence of an inductive substance of mineralized tissue

Bioassay of human tooth protein blotted polyvinylidene difluoride(PVDF) membrane

PURPOSE: Human tooth proteins are highly heterogeneous, comprising diverse proteins derived from a number of genes. The attempts to identify protein for activity of tooth matrix proteins have been defied by several factors. First, the amount of proteins within teeth is very small relative to many extracellular matrix proteins of other tissues. Second, the bioassay system is tedious and needed for long time. Therefore we tried to find easy techniques, which increase the product rate, and an assay of small proteins, with which amino acid sequence is possible without additional procedures. Materials and METHODS: Total protein were extracted from 300 g enamel removed teeth and 600 g teeth with 4 mol/L guanidine HCl and purified by gel chromatography. Aliquot of proteins was implanted into muscle pouches in Sprague-Dawley rats for bioassay. By SDS-PAGE and membrane blotting, molecular weight of each protein was estimated and a partial amino acid sequence was obtained. Each fraction blotted on the membrane was cut out and inserted in rat ectopic model. RESULTS: In dissociative method, total tooth proteins were obtained 1mg/ml from enamel removed teeth and 3.5 mg/ml from teeth. In SDS-PAGE, four clear bands at the sites corresponding to 66, 40, 20 and 18 kD. Especially The 66 kD band was clearly exhibited. Amino acid sequencing from tooth could be possible using PVDF membrane blotting technique. In amino acid sequencing, 66 kD protein was identified as albumin. CONCLUSION: Compared with conventional method for extraction of teeth protein and bioassay of proteins, the methods in this study were easy, time-saving and more productive technique. The matured tooth proteins omitting additional procedure of mechanical removal of enamel were simply analyzed using blotted PVDF membrane. This method seems to make a contribution as a technique for bioassay and amino acid sequencing of protein.