A Survey About Dental Instruments at the Primary Health Care in Brazil.

This study describes the structure of oral health services in primary health care in Brazil and the instruments available for the provision of oral health care and to compare the number of instruments according to organizational characteristics of health services and among the macroregions. Of the 23,251 oral health teams (OHTs) in the Public Health System, 17,513 (75.3%) participated in this study. Trained researchers observed the structures of the health services and determined the presence of and whether a sufficient quantity of 36 dental instruments existed. The score of each oral health service was determined by the sum of the number of dental instruments present in sufficient quantity (0 to 36). Central tendency measures were compared along with the variability in these scores according to the organizational characteristics of the services and according to the Brazilian macroregion. No instrument was found to be present in all evaluated services. Basic, surgical and restorative instruments were the most frequently found. Periodontal, endodontic and prosthetic instruments exhibited the lowest percentages. The mean and median numbers of dental instruments were higher for teams that operated over more shifts, those with an oral health technician and those in the South and Southeast regions. The oral health services were equipped with basic, surgical and restorative instruments. Instruments designed for periodontal diagnosis, emergency care and denture rehabilitation were less frequently found in these services. The worst infrastructure conditions existed in the OHTs with the worst forms of care organization and in regions with greater social issues.

A survey about dental instruments at the primary health care in Brazil

Abstract This study describes the structure of oral health services in primary health care in Brazil and the instruments available for the provision of oral health care and to compare the number of instruments according to organizational characteristics of health services and among the macroregions. Of the 23,251 oral health teams (OHTs) in the Public Health System, 17,513 (75.3%) participated in this study. Trained researchers observed the structures of the health services and determined the presence of and whether a sufficient quantity of 36 dental instruments existed. The score of each oral health service was determined by the sum of the number of dental instruments present in sufficient quantity (0 to 36). Central tendency measures were compared along with the variability in these scores according to the organizational characteristics of the services and according to the Brazilian macroregion. No instrument was found to be present in all evaluated services. Basic, surgical and restorative instruments were the most frequently found. Periodontal, endodontic and prosthetic instruments exhibited the lowest percentages. The mean and median numbers of dental instruments were higher for teams that operated over more shifts, those with an oral health technician and those in the South and Southeast regions. The oral health services were equipped with basic, surgical and restorative instruments. Instruments designed for periodontal diagnosis, emergency care and denture rehabilitation were less frequently found in these services. The worst infrastructure conditions existed in the OHTs with the worst forms of care organization and in regions with greater social issues.

Resumo Este estudo descreve a estrutura dos serviços de saúde bucal na atenção primária em saúde no Brasil e os instrumentos disponíveis para a assistência à saúde bucal e compara o número de instrumentais de acordo com as características organizacionais dos serviços de saúde e entre as macrorregiões. Das 23.251 equipes de saúde bucal (ESB) no Sistema Único de Saúde, 17.513 (75,3%) participaram deste estudo. Pesquisadores treinados observaram a estrutura dos serviços de saúde e determinaram a presença e a existência de uma quantidade suficiente de 36 instrumentais odontológicos. A pontuação de cada serviço de saúde bucal foi determinada pela soma do número de instrumentos dentários presentes em quantidade suficiente (0 a 36). As medidas de tendência central e de variabilidade desse escore foram comparadas com as características organizacionais dos serviços e de acordo com a macrorregião brasileira. Nenhum instrumental foi encontrado em todos os serviços avaliados. Os instrumentos básicos, cirúrgicos e restauradores foram os mais frequentemente encontrados. Os instrumentos periodontais, endodônticos e para realização de prótese exibiram as percentagens mais baixas. O número médio e mediano de instrumentos dentários foi maior para as equipes que operavam em mais turnos, aqueles com um técnico em saúde bucal e aqueles nas regiões Sul e Sudeste. Os serviços de saúde bucal estavam equipados com instrumentos básicos, cirúrgicos e restauradores. Os instrumentos indicados para diagnóstico periodontal, cuidados de emergência e reabilitação com próteses dentárias foram menos frequentemente encontrados nesses serviços. As piores condições de infra-estrutura existiam nos ESB com as piores formas de organização de cuidados e em regiões com maiores problemas sociais.

Influência da conicidade e do ponto de imobilização na flexibilidade dos instrumentos de níquel-titânio rotatórios RaCe / Influence of taper and immobilization point on the flexibility of RaCe nickel-titanium rotary instruments

Objetivo: esse estudo comparou a flexibilidade de instrumentos de níquel-titânio rotatórios com diferentes conicidades, em diferentes diâmetros da haste helicoidal cônica (D3 e D6). Métodos: trinta instrumentos RaCe (FKG, La Chaux-de Fonds, Suíça), #40 (D0 = 40), com 25 mm de comprimento, foram divididos em três grupos (n = 10), de acordo com sua conicidade. No teste de flexão em cantiléver (45 graus), foram realizadas duas avaliações, com cargas aplicadas, em D3 e D6, para cada grupo. Resultados: a comparação das cargas aplicadas em D3 e D6 nos instrumentos RaCe com diferentes conicidades mostrou valores de carga máxima significativamente diferentes para flexionar os instrumentos: D3 < D6, com a flexibilidade em D3 maior do que em D6. A comparação das cargas aplicadas em D3 nos três grupos revelou diferenças significativas entre os grupos (p < 0,0001), enquanto o teste Student-Newman-Keuls (SNK) mostrou diferenças de flexibilidade entre os três grupos: 0,06 < 0,04 < 0,02mm/mm. O mesmo resultado foi encontrado na comparação da força aplicada em D6. Conclusões: a flexibilidade do instrumento aumenta com a redução da conicidade (p < 0,05) e diminui com o aumento no diâmetro do eixo helicoidal (p < 0,05).

Efecto de la esterilización en la Resistencia a fatiga cíclica de limas Hyflex CM®,a nivel coronal y apical / Effect of sterilization cycles on cyclic fatigue resistance of hyflex CM files, at coronal and apical levels

Objetivo: comparar la resistencia a fatiga cíclica de las limas HyFlex CM® nuevas y esterilizadas tanto a nivel apical como coronal. Material y método: 180 limas se dividieron en seis grupos (n=30): dos de limas nuevas (A5, A11), dos de limas esterilizadas una vez (B5, B11) y dos de limas esterilizadas dos veces (C5,C11). Se evaluó la resistencia a fatiga cíclica (FC) a 5 mm y a 11 mm de la punta. El análisis de Weibull se utilizó para calcular los parámetros de vida media, beta y eta y comparar los grupos. Resultados: Las limas nuevas fueron significativamente más resistentes a la FC que las esterilizadas una o dos veces, con una probabilidad de 72% y 61% a 5 mm de la punta y de un 75% y 72% a 11 mm de la punta, respectivamente. No hubo diferencias estadísticamente significativas entre la vida media de las limas esterilizadas una o dos veces a 11 mm de la punta, sin embargo las limas esterilizadas dos veces fueron significativamente más resistentes a 5 mm de la punta, con una probabilidad de 63%. En todos los grupos, las limas fueron significativamente más resistentes a nivel apical que coronal con una probabilidad superior al 99%. Conclusiones: Las limas HyFlex CM® fueron más resistentes a la FC a nivel apical que coronal. Los instrumentos HyFlex CM® no esterilizados fueron los más resistentes

Aim: to compare cyclic fatigue resistance of new and sterilized HyFlex CM® files at apical and coronal levels. Methods: 180 files were divided in six groups (n=30): two of new files (A5, A11), two autoclaved once (B5, B11) and two autoclaved twice (C5, C11). Cyclic fatigue resistance was tested at 5 mm and at 11 mm from the tip. Weibull analysis was used to calculate the mean life, beta, and eta parameters. Results: New files will last significantly longer than files that were sterilized once or twice, with a probability of 72% and 61% at 5 mm from the tip and 75% and 72% at 11 mm from the tip, respectively. There was no statistically significant difference between the mean life of the files sterilized once or twice at 11 mm from the tip, but at 5 mm from the tip, files sterilized twice was significantly longer than those sterilized once, with a probability of 63%. Files will last significantly longer at 5 mm than 11 mm from the tip with a probability higher than 99%. Conclusions: HyFlex CM® files were more resistant to cyclic fatigue at the apical than the coronal levels. Unsterilized HyFlex CM® files were the most resistant

Use of Magnifying Loupes among Dental Professionals.

AIM: The study aims to determine the perspective of dental professionals towards magnifying loupes and the selection criteria used while purchasing them. MATERIALS AND METHODS: In this regard, a close-ended questionnaire was structured and distributed among 111 dental professionals. The questionnaire was designed to obtain information regarding the usage of magnifying loupes in dental practices and procedures, limiting factors, and selection criteria for purchasing. The results obtained from this study were statistically analyzed with the help of SPSS. RESULTS: The findings illustrated that most respondents considered the use of magnifying loupes beneficial in dental practices. Also, 20.7% of them preferred "Through-the-Lens" magnifying loupes over "Flip-up" ones. Furthermore, many of the respondents considered that price, magnification, and resolution are the main factors in terms of selection criteria. CONCLUSION: Although, there is an immense growth seen in the usage of magnifying loupes in dentistry; still there is a need to increase the awareness of the dental professionals regarding the positive outcomes of magnification aids in dentistry. CLINICAL SIGNIFICANCE: The study will help enlightening clinicians regarding the selection criteria while purchasing magnifying loupes for dental practices.

Conduta clínica frente à fratura de instrumentos endodônticos: relato de dois casos clínicos / Clinical management of endodontic instrument fracture: report of two clinical cases

Introdução: a fratura de um instrumento endodôntico constitui sério risco à continuidade do tratamento. A utilização abusiva e repetitiva dos instrumentos, a fadiga do metal, a falta de conhecimento das suas características físicas, o desrespeito à cinemática, a não observação de deformações, a pressão ou torção exagerada durante o preparo do canal radicular e a pouca habilidade do profissional contribuem para a fratura dos instrumentos endodônticos. Diante desse problema, as opções são a remoção dos instrumentos via canal, cirurgia periapical ou mantê-lo no interior dos canais. Objetivos: no presente trabalho, serão apresentados dois casos clínicos nos quais ocorreu o mesmo acidente: fratura de espiral Lentulo. Todavia, devido às particularidades de cada caso, optou-se por condutas clínicas diferentes. Relato de caso: no primeiro caso, em função da dificuldade de remoção e particularidades anatômicas, optou-se pela obturação com o fragmento no canal; no segundo caso, realizou-se a remoção do instrumento que obstruía o forame apical, empregando uma técnica simples e acessível, utilizando uma agulha hipodérmica associada a um instrumento manual. Conclusão: em função do exposto, é imperativo que o profissional, além de deter habilidade e experiência para conduzir os casos, tenha conhecimento sobre as características dos instrumentos por ele empregados, pois a cuidadosa aplicação dos princípios de uso irá minimizar a ocorrência de acidentes e complicações.

Comportamento mecânico de instrumentos WaveOne e ProTaper em relação à torção, dureza e tenacidade / Mechanical properties of WaveOne and ProTaper instruments in relation to torsion, hardness and toughness

Objetivo: esse estudo teve como objetivo avaliar a resistência à fratura por torção de duas marcas de instrumentos mecanizados de NiTi, com formas geométricas distintas e produzidas por ligas metálicas diferentes. Métodos: quinze instrumentos WaveOne Large e quinze ProTaper F4 foram selecionados e submetidos aos ensaios mecânicos de torção, microdureza Vickers e tenacidade. No ensaio de torção, foram avaliados a deformação angular até a fratura e o torque máximo. As superfícies fraturadas e as hastes helicoidais dos instrumentos foram analisadas por meio de microscopia eletrônica de varredura (MEV). Resultados: os valores do ângulo máximo em torção foram maiores para o ProTaper, enquanto o torque máximo em torção (N/cm) foi maior para o WaveOne. Os valores de microdureza Vickers foram maiores para a liga NiTi M-Wire, enquanto o grupo controle apresentou maior tenacidade. O teste t de Student demonstrou diferença significativa nos ensaios de torção (p < 0,05), tenacidade e microdureza Vickers. A análise do MEV revelou deformação plástica ao longo das hélices helicoidais de todos os instrumentos fraturados e fratura tipo dúctil. Conclusão: os instrumentos fabricados em NiTi M-Wire apresentaram maior resistência à fratura por torção e maior microdureza, em comparação aos de NiTi convencional. Devido ao maior ângulo de torção do ProTaper e à maior deformação até a fratura, esses parâmetros tornam esse instrumento mais seguro do ponto de vista clínico.

Métodos e dispositivos que auxiliam na remoção de instrumentos fraturados: revisão de literatura / Methods and devices that assist the removal of fractured file: Literature review

A fratura de instrumento durante a terapia endodôntica é uma complicação indesejável, que pode levar ao insucesso do tratamento. Quando isso acontece, exige-se novo planejamento do caso, visando uma mudança de conduta, com o intuito de remover ou ultrapassar o instrumento. É importante, nesse momento, que o profissional conheça inúmeras técnicas e domine os instrumentos para executá-las. No presente estudo, foi realizada uma revisão de literatura na qual concluiu-se que a remoção de instrumentos fraturados em canais retos é mais facilmente realizada do que em canais curvos, em que o uso de ultrassom associado ao microscópio operatório aumenta significativamente o sucesso da remoção; ainda, que, na impossibilidade da retirada do instrumento fraturado no interior do canal, a ultrapassagem desse tem o melhor prognóstico para o tratamento.

Use of a Dental Vibration Tool to Reduce Pain From Digital Blocks: A Randomized Controlled Trial.

BACKGROUND AND OBJECTIVES: The infiltration of local anesthetic is consistently described as painful by patients. Vibration anesthesia has been studied in the dental literature as a promising tool to alleviate the pain from dental nerve blocks. Many of these studies used a specific device, the DentalVibe. To date, there have not been any studies applying this technology to digital blocks of the hand in human subjects. We hypothesized that the use of microvibratory stimulation during digital blocks of the hand would decrease pain reported by patients. METHODS: This was a randomized controlled trial of consenting adult emergency department patients who received digital block anesthesia for hand digit therapy when study authors were present. The study period was 24 months at an academic emergency department. A sample size of 50 injections (25 subjects) was necessary for a power of 80% to detect a mean difference of 2 (SD, 2.5) on the pain scale. A 2-sided dorsal injection approach was used for digital blocks. Subjects were randomized to either intervention (vibration) for the first injection or sham (device off). Both intervention and sham were held in place for 5 seconds prior to and during injection. Subjects were given 2 mL of 1% lidocaine and asked to rate the injection pain on a 1- to 10-point scale. This process was then repeated. Mean pain scores were compared using paired t tests. Our primary outcome was the difference in mean injection pain score between sham versus intervention groups. RESULTS: There were 25 patients in the study group (mean age, 35.52 years [range, 18-58 years]; 8 females; 11 non-Hispanic white). The mean injection pain score in the sham group was 4.28 (95% confidence interval [CI], 3.14-5.42), and in the intervention group, the mean pain score was 2.52 (95% CI, 1.62-3.42). For the primary outcome, the mean injection pain score difference between the sham and intervention groups across all subjects was 1.76 (95% CI, 0.49-3.03; P = 0.009). The mean injection pain score differences were similar across groups: females versus males (0.24; 95% CI, -2.31 to 2.79; P = 0.85), non-Hispanic whites versus other races (0.76; 95% CI, -1.78 to 3.29; P = 0.54), intervention first versus sham first (-0.43; 95% CI, -3.25 to 2.40; P = 0.75). CONCLUSIONS: Our results show a statistically significant difference in mean injection pain score during digital block of the hand when the DentalVibe device is used for vibration anesthesia. Larger studies are warranted to confirm our findings.

Durabilidad de las fresas de diamante tras realizar desgastes en dientes naturales, comparando 4 marcas comerciales, analizado en microscopía electrónica / Diomond Burs durability, aer tooth wears, 4 brands compaired. Electronic Microscopy analysis

Antecedentes: Los hallazgos reportados en la literatura no relacionan directamente la efectividad de corte de las fresas de diamante de alta velocidad con la cantidad y calidad de diamantes en la superficie, ni su vida media después de un determinado número de usos. Objetivo: Evaluar la durabilidad de los diamantes de corte de la superficie activa de las fresas después de realizar desgastes en dientes naturales. Métodos: Este estudio ex vivo comparó 4 marcas comerciales de fresas de diamante con granos de 64-126 |zm, de forma troncocónica y punta redonda (norma ISO 850): MDT", Swisstech*, Pointech* y Jota". Se realizaron 5 cortes de 0,16 mm con cada fresa en la corona del diente. Luego se analizaron las fresas en microscopio electrónico de barrido para observar: a) adhesión de diamantes al sustrato en cabeza y cuerpo; b) estado de los diamantes en el sustrato en cabeza y cuerpo, tras los 5 cortes; y c) estadofinal de las fresas. Se realizó un análisis cualitativo y cuantitativo. Resultados: Todas las fresas de las 4 marcas presentaron similar desgaste después de los 5 usos, tanto en la cabeza como el cuerpo. Pese a que todas las muestras presentaban variaciones, en algunas fue más evidente el desalojo y fractura de los diamantes. Conclusión: El estudio sugiere que las fresas deberían cambiarse después de 5 usos clínicos para garantizar un desgaste adecuado y evitar daños pulpares ocasionados por la fricción.

Background: Outcomes reported in the literature do not relate cutting effectiveness of high-speed diamond drills directly to the diamond surface amount and quality, not either their average life after a specific number of uses. Objective: To evaluate the durability of diamond burrs in the drill active surface after doing removal in natural teeth. Methods: This ex vivo study compared dental drills of four different brand names with 64-126 pm, round tip, conical-trunk diamond grit (ISO 850): MDT", Swisstech", Pointech* and Jota". Five 0.16 mm cuts were carried out using each dental drill on a tooth crown. The dental drills were then analyzed under the scanning electron microscope in order to observe: a) any adhesion of diamond to substrate in the head and body; b) condition of the diamonds in the substrate, in head and body, after 5 cuts; and c) final condition of the dental drills. Then a qualitative and quantitative analysis was carried out. ResuJts: The four different dental drills showed a similar worn condition after five uses, both in the head and body. Despite all the samples showed variations, some of them had greater evidence of diamond fracture and displacement. Conclusion: This study suggests that the dental drills should be changed over after 5 clinical uses in order to ensure a desirable worn condition and prevent pulpal damage due to the friction.

Caracterização geométrica, dimensional e avaliação da eficiência de corte dos instrumentos endodônticos de níquel-titânio BioRaCe e BT-RaCe / Geometric characterization, dimensional and cutting efficiency evaluation of nickel-titanium endodontic instruments BioRaCe and BT-RaCe

A capacidade e eficiência de corte dos instrumentos endodônticos de Níquel-Titânio (NiTi) são complexas e relacionadas a diversos fatores, como a técnica de instrumentação utilizada e as características geométricas e dimensionais dos instrumentos. Neste trabalho, o objetivo foi avaliar a ação de corte através do torque exercido durante o preparo de canais radiculares por instrumentos BioRaCe, (FKG Dentaire Swiss Endo - La Chaux-de-Fonds, Suíça) BR0 25/.08, BR1 15/.05, BR2 25/.04, BR3 25/.06, BR4 35/.04 e BT-RaCe (FKG Dentaire Swiss Endo - La Chaux-de-Fonds, Suíça) BTR1 10/.06, BTR2 35/.00 e BTR3 35/.04. Inicialmente, os instrumentos foram caracterizados com relação ao diâmetro a cada milímetro da parte ativa e comprimento de pitch. Os instrumentos foram fotografados e a análise das imagens foi realizada com o software ImageJ. Os ensaios de eficiência de corte foram realizados em 20 pré-molares com duas raízes distintas com curvatura gradual e discreta entre 10º e 25º (classe I) e comprimento total dos canais entre 19 e 23mm, selecionados do banco de dentes da FOUFMG. Após radiografia digital inicial, foi realizado acesso coronário e odontometria com limas manuais de aço inoxidável K#10 e K#15. Dez dentes foram instrumentados seguindo a técnica preconizada pelo fabricante para cada sistema. Um multímetro, acoplado ao motor endodôntico, registrou o torque requerido por cada instrumento durante o preparo dos canais. A ação de corte e o comportamento dos instrumentos durante o preparo dos canais foram avaliados através das curvas torque versus tempo. Os resultados da caracterização geométrica e dimensional dos instrumentos indicaram que a medida dos mesmos é compatível com os valores preconizados pelo fabricante. Na análise do comprimento de pitch, as limas mostraram arestas de corte alternadas e progressivas, exceção apenas para a BTR2, cujo pitch foi constante. Quanto ao tempo de utilização dos instrumentos, os resultados indicaram que os sistemas BioRaCe e BT-RaCe demonstraram diferenças nos tempos dos ensaios de eficiência de corte, devido, principalmente, à diferença do número de instrumentos utilizados em cada sequência. Por fim, não houve diferença estatística entre a ação de corte dos instrumentos que demandaram maior torque médio durante a instrumentação, BR3 para o sistema BioRaCe e BTR3 para o sistema BT-RaCe. A diminuição do número de instrumentos para o preparo de canais mostrou, nas limitações deste estudo e nas sequencias avaliadas, um torque máximo seguro para o uso clínico, bem como a diminuição do tempo clínico

The cutting abiblity and efficiency of Niquel Titanium (NiTi) endodontic instruments are complex and related to many different factors such as the instrumentation technique and the gemetric and dimensional characteristics of the instruments. The goal of the present work was to assess the cutting action through the torque exerted during the preparation of root canals with BioRaCe instrumets, (FKG Dentaire Swiss Endo-La Chaux-de-Fonds, Suiça)...

Avaliação em microCT do preparo dos canais mesiais de molares inferiores realizado por dois sistemas rotatórios de NiTi / Micro-CT evaluation of mesial canals preparation performed by two rotary NiTi systems in mandibular molars

Objetivo: avaliar em microCT a qualidade do preparo e desgaste das paredes mesiais e de furca de molares inferiores. Métodos: trinta molares inferiores humanos foram extraídos e escaneados em microCT. Os parâmetros analisados foram: centralização do canal radicular, extensão e direção do desvio na instrumentação, quantidade de dentina removida, espessura mínima de remanescente e os volumes apical e total antes e após instrumentação. Os dentes foram divididos em 3 grupos (n = 10): Grupo 1 = instrumentação com ProTaper até o instrumento F2; Grupo 2 = Twisted File, instrumento 25/08; Grupo 3 = instrumentação manual (controle). Resultados: não houve diferença significativa (p > 0,05) entre os sistemas rotatórios, em relação ao desvio na instrumentação, em todos os níveis analisados. O terço cervical apresentou maior quantidade de desvio na instrumentação quando comparado ao nível apical, e menor quantidade de remanescente, especialmente na zona de furca. Os sistemas removeram maior quantidade de dentina das paredes de furca (terço médio e cervical). Não houve diferença entre os grupos em relação à quantidade de dentina no terço apical. Os volumes apical e total não aumentaram significativamente após o preparo com os instrumentos rotatórios. Conclusão: os sistemas rotatórios de NiTi avaliados não aumentaram significativamente os volumes apical e total dos canais radiculares. O maior desvio na instrumentação ocorreu nos terços médio e cervical para todos os sistemas analisados. Para todos os grupos analisados, a quantidade de remanescente foi significativamente reduzida na direção da furca dos terços médio e cervical.

Techniques and materials used by general dentists during endodontic treatment procedures: Findings from The National Dental Practice-Based Research Network.

BACKGROUND: Little is known about which materials and techniques general dentists (GDs) use during endodontic procedures. The objectives were to quantify GDs' use of specific endodontic tools, quantify inappropriate use, and ascertain whether inappropriate use is associated with GDs' practice characteristics. METHODS: GDs in The National Dental Practice-Based Research Network reported in a questionnaire materials and techniques they use during endodontic procedures. RESULTS: Among eligible GDs, 1,490 (87%) participated. Most (93%; n = 1,383) used sodium hypochlorite to irrigate. The most commonly used sealers were zinc oxide eugenol (43%) and resin (40%), followed by calcium hydroxide (26%). Most (62%; n = 920) used a compaction obturation technique; 36% (n = 534) used a carrier-based method. Most (96%; n = 1,423) used gutta-percha as a filler; 5% used paste fillers. Few used irrigants (n = 46), techniques (n = 49), or fillers (n = 10) that investigators classified as inappropriate. CONCLUSIONS: GDs use a broad range of endodontic techniques and materials, often adapting to newer technologies as they become available. Few GDs use tools that the investigators classified as inappropriate. PRACTICAL IMPLICATIONS: GDs use many types of endodontic techniques and materials, but only a small percentage of them are inappropriate.

Fadiga cíclica flexural de instrumentos Hyflex CM e TF Adaptive em diferentes situações experimentais / Flexural cyclic fatigue of instruments Hyflex CM and TF Adaptive in diferente experimental situations

O presente estudo teve como objetivo avaliar a resistência à fadiga cíclica flexural dos instrumentos de níquel- titânio, Hyflex CM (Coltène, EUA) e TF Adaptive (SybronEndo, EUA) em diferentes situações experimentais. Todas as limas que foram selecionadas possuíam conicidade 0,04 e diâmetro de ponta 35. Utilizou-se um dispositivo desenvolvido especificamente para realizar o ensaio flexural dinâmico. Os instrumentos TF Adaptive foram divididos em 3 grupos de acordo com o ângulo de curvatura do ensaio: 45º, 60º e 90º e cada grupo subdividido em 2 subgrupos de acordo com o tipo de movimento: rotação contínua e Adaptive. Cada subgrupo era composto por 15 instrumentos TF Adaptive, totalizando 90 instrumentos. Quinze instrumentos Hyflex CM formavam o grupo 4, no ensaio com ângulo de curvatura 90 graus e rotação contínua. A simulação foi realizada em canais artificiais de aço com ângulo de 45, 60, 90 graus e raio 5m m. O número de ciclos e o tempo em segundos até a fratura foram tabulados e analisados. Entretanto, a fadiga cíclica flexural foi significante maior nos três grupos em movimento Adaptive. E as limas TF Adaptive em seu próprio movimento tiveram maior número de ciclos e tempo até a fratura quando comparadas as Hyflex CM no ensaio de 90 graus. Portanto, conclui-se que o sistema Adaptive (limas TF Adaptive + movimento Adaptive) foi mais seguro à resistência á fadiga flexural, e no ensaio de 90 graus o sistema Adaptive foi mais resistente quando comparado com as limas Hyflex CM no movimento de rotação contínua.

The aim of this work to evaluate the cyclic fatigue resistance flexural the instruments of nickel-titanium, HyFlex CM (Coltène, USA) and TF Adaptive (SybronEndo, USA) in different experimental situations. All files that were selected had 0.04 taper and tip diameter 35. We used a device developed specifically to perform the dynamic flexural test. The TF Adaptive instruments were divided into 3 groups according to the angle of curvature of the test: 45, 60 and 90 and further divided in two subgroups according to the type of movement: continuous rotation and Adaptive. Each group consisted of 15 instruments TF Adaptive totaling 90 instruments. Fifteen HyFlex CM instruments formed the group 4 in the trial of bend angle 90 degrees and continuous rotation. The simulation was performed in artificial steel angled channels 45, 60, 90 degrees and radius 5m m. The number of cycles and the time in seconds until fracture were tabulated and analyzed. However, the cyclical flexural fatigue was significantly greater in the three groups Adaptive motion. And the TF Adaptive files on your own movement had a higher number of cycles and time to fracture when the HyFlex CM compared in 90-degree test. Therefore, it is concluded that the adaptive system (TF Adaptive Motion + Adaptive files) was safer resistance to flexural fatigue, and 90 degrees test Adaptive system is more resistant when compared with the HyFlex files into continuous.

Análise da resistência à fadiga flexural de instrumentos fabricados com a tecnologia CM após ensaios de flexão e ciclos de esterilização / Effect of bending and sterilization on the fatigue resistance of thermally treated nickel-titanium instruments

A tecnologia "Controlled Memory (CM)", que envolve o emprego de tratamentos térmicos em instrumentos já usinados, é uma das novas estratégias propostas pelos fabricantes de instrumentos endodônticos de NiTi para aumentar sua flexibilidade e resistência à fadiga. O objetivo desse trabalho foi avaliar a capacidade de recuperação de forma e a manutenção das propriedades mecânicas dos instrumentos Hyflex CM (HF; Coltene/Whaledent, USA) e Typhoon CM (TYP; Clinician's Choice Dental Products, USA), de diâmetro e conicidade 30/.06, após serem submetidos a ciclos de flexão até 45º (especificação ISO 3630-1) e esterilização em autoclave. Dez instrumentos de cada sistema foram submetidos a dobramento a 45º, esterilizados em autoclave a 134° por 20 minutos e fotografados com uma câmera de alta resolução em lupa estereoscópica, para mensuração da deformação residual. Foram realizados cinco ciclos de flexão, alternados com ciclos de esterilização. As imagens foram analisadas no software Image J 1.48V. O número médio de ciclos até a fratura por fadiga (Nf) de instrumentos novos e de instrumentos submetidos à flexão e esterilização foi obtido em um dispositivo de bancada que simula um canal curvo. Ambos os instrumentos apresentaram valores semelhantes de momento de dobramento a 45º (Mb45) (p=0,239) e verificou-se uma redução nestes valores após os ciclos de flexão e esterilização, porém com resultado estatístico apenas para HF (p=0,005). Quando submetidos à esterilização, os instrumentos HF recuperaram totalmente sua forma inicial reta, ao contrário dos instrumentos TYP (p=0,000), que apresentaram deformação residual média em torno de 2,7º. Instrumentos TYP submetidos a cinco ciclos de flexão e esterilização apresentaram queda na sua resistência à fadiga (p=0,006), o que não ocorreu com HF (p=0,825). Os instrumentos avaliados no presente trabalho, embora produzidos empregando tratamentos térmicos referenciados como tecnologia CM, apresentaram capacidade de recuperação de forma e resistência à fadiga distintas

The use of Controlled Memory technology involving the heat treatment of machined NiTi instruments is among the new strategies manufacturers have developed to improve files' fatigue resistance and flexibility. The aim of this study was to evaluate the shape recovery capacity and maintenance of mechanical properties of Hyflex CM (HF; Coltene/Whaledent, USA) and Typhoon CM (TYP; Clinician's Choice Dental Products, USA) after being submitted to bending at 45°, sterilization and fatigue stresses. Ten instruments from each brand were submitted to the 45° bending test, according specification ISO 3630-1, autoclaved at 134°C for 20 minutes and photographed with a high resolution camera and with magnification to check whether all files have returned to their original shape. The images were analyzed in the software Image J 1.48V. In order to reproduce the clinical practice, five bending cycles were alternated with sterilization cycles. The average number of cycles until failure (Nf) were obtained for new instruments and instruments submitted to bend and sterilization in a bench device that simulates a curved canal. Both brands presented similar values of bending moments at 45º (Mb45) (p=0,239). A decrease in this values were verified after the five cycles of bending and sterilization, however only statistically relevant for HF instruments (p= 0,005). When submitted to sterilization, all HF instruments recovered their original shape. On the other hand, a significant number of TYP instruments were shown to be plastically deformed (p= 0,000) with an average residual deformation of 2,7°. TYP instruments submitted to five cycles of bending and sterilization presented a statistically significant decrease in their Nf (p=0,006), which did not occur to HF instruments (p=0,825). The two types of instruments tested in this study, although referenced as CM instruments, responded differently to thermal treatments applied during the manufacturing process and presents distinct shape recovery capacity and fatigue resistance

Evaluation of bone heating, drill deformation, and drill roughness after implant osteotomy: guided surgery and classic drilling procedure.

PURPOSE: This study evaluated and compared bone heating, drill deformation, and drill roughness after several implant osteotomies in the guided surgery technique and the classic drilling procedure. MATERIALS AND METHODS: The tibias of 20 rabbits were used. The animals were divided into a guided surgery group (GG) and a control group (CG); subgroups were then designated (G0, G1, G2, G3, and G4, corresponding to drills used 0, 10, 20, 30 and 40 times, respectively). Each animal received 10 sequential osteotomies (5 in each tibia) with each technique. Thermal changes were quantified, drill roughness was measured, and the drills were subjected to scanning electron microscopy. RESULTS: Bone temperature generated by drilling was significantly higher in the GG than in the CG. Drill deformation in the GG and CG increased with drill use, and in the CG a significant difference between G0 and groups G3 and G4 was observed. In the GG, a significant difference between G0 and all other groups was found. For GG versus CG, a significant difference was found in the 40th osteotomy. Drill roughness in both groups was progressive in accordance with increased use, but there was no statistically significant difference between subgroups or between GG and CG overall. CONCLUSION: During preparation of implant osteotomies, the guided surgery technique generated a higher bone temperature and deformed drills more than the classic drilling procedure. The increase in tissue temperature was directly proportional to the number of times drills were used, but neither technique generated critical necrosis-inducing temperatures. Drill deformation was directly proportional to the number of times the drills were used. The roughness of the drills was directly proportional to the number of reuses in both groups but tended to be higher in the GG group.

A survey of adoption of endodontic nickel-titanium rotary instrumentation part 1: general dental practitioners in Wales.

OBJECTIVE: To assess adoption of endodontic nickel-titanium (NiTi) rotary technology by general dental practitioners and identify factors influencing its uptake. DESIGN: Postal questionnaire. SETTING: General dental practitioners working in Wales. METHODS: General dental practitioners (n = 584) were approached regarding their usage or otherwise of nickel-titanium rotary instrumentation during root canal shaping. The postal questionnaire took the form of an anonymous survey comprising 13 questions. These questions covered usage parameters, satisfaction, training issues and reasons for avoidance of NiTi instruments. RESULTS: The response rate was 71%. Nickel-titanium rotary instruments were used routinely by 67% of those responding practitioners. Principle factors cited as being implicated in the decision to not adopt NiTi use included cost (65% of responses), lack of training and the perceived risk of instrument fracture. CONCLUSIONS: Over two thirds of dental practitioners in Wales use rotary NiTi endodontic technology with the majority having converted to such systems more than three years ago. There was, however, a significant disparity in NiTi usage between solely NHS practitioners (42%) and private practitioners (90%). Continued provision of high quality hands-on practical workshops may be of benefit in facilitating a positive initial NiTi experience in order to assist the transfer to these newer technologies.

A survey of adoption of endodontic nickel-titanium rotary instrumentation part 2: community and hospital dental practitioners in Wales.

OBJECTIVES: To assess adoption of endodontic nickel-titanium rotary technology (NiTi) by community and hospital dental clinicians within Wales and identify factors that may restrict uptake. DESIGN: Postal questionnaire. SETTING: Community and hospital-based dentists in Wales. METHODS: Community and hospital-based dentists with a remit for provision of restorative dentistry (community dental setting = 32; hospital dental setting = 36) were approached regarding their usage or otherwise of nickel-titanium rotary instrumentation for endodontic treatments. The postal questionnaire took the form of an anonymous survey comprising 12 questions. These questions covered usage parameters, satisfaction and training and broached reasons for NiTi avoidance. RESULTS: The response rate was 77%. NiTi rotary instruments were used routinely by an encouraging 82% of those in the hospital-based restorative dental services but only 13% of community staff. Factors cited as being implicated in the decision to avoid their use included cost (62% of responses) lack of training and the perceived lack of benefit. CONCLUSION: The adoption of rotary NiTi endodontic technology by the hospital dental practitioners of Wales is encouraging with the majority having converted to such systems in excess of three years prior to the survey. There was, however, a significant disparity in NiTi usage between community and hospital settings, the implications for which and possible solutions for increased training and uptake are discussed.

The use of radiography and the apex locator in endodontic treatment within the UK: a comparison between endodontic specialists and general dental practitioners.

AIM: To investigate the attitudes of general dental practitioners (GDPs) and specialist endodontists working in the UK in the use of radiography and apex locators during root canal treatment and to see if use was related to respondent's age and the year of graduation. METHODOLOGY: A postal questionnaire was sent to 857 randomly selected GDPs and all endodontic specialists working in the UK (170). Non-responders were sent a further two mailings. Chi-squared tests were used to compare both groups at the P < 0.05 level of significance. For nonparametric data, the Mann-Whitney U test was employed. RESULTS: The overall response rate was 73%. There were significant differences between endodontic specialists and GDPs in the prescription of the preoperative, the cone-fit and the postoperative radiograph. A total of 114 (86.4%) endodontic specialists and 321 (53.2%) GDPs reported using an apex locator (P < 0.001). Eighty-eight (66.7%) endodontists and 217 (36%) GDPs used an apex locator and a radiograph to determine the working length for a single-rooted tooth (P < 0.001). For multi-rooted teeth, 91 (68.9%) endodontists and 229 (38%) GDPs used a combined approach of an electronic apex locator and a working-length radiograph (P < 0.001). One-millimetre short of the radiographic apex was employed by 56.2% of respondents as the apical limit. There were significant differences (P < 0.001) between the two groups with regard to routine radiographic follow-up. CONCLUSIONS: Both endodontists and GDPs were found to be observing national guidelines when performing root canal treatment. Greater use of apex locators was found amongst endodontists who tended to use a combined approach of an apex locator and periapical radiography.