Avaliação da Fidedignidade de Diferentes Marcas de Réguas Endodônticas Milimetradas / Assessment of the Reliability of Different Millimeter Endodontic Ruler Brands

Introdução: A determinação adequada do comprimento de trabalho durante o tratamento endodôntico é essencial para o seu sucesso. Problemas de ordem clínica podem surgir quando diferentes marcas são utilizadas. A determinação do CT (Comprimento de Trabalho) aquém ou além e desajustes do cone principal no momento da obturação do SCR (Sistema de Canais Radiculares), são alguns exemplos. Objetivo: avaliar a fidedignidade das medidas de 3 marcas comerciais de réguas milimetradas para verificar sua precisão e padronização. Materiais e métodos: Foram utilizadas um total de 15 réguas: Grupo 1- Angelus (n=5), Grupo 2 - Jon (n=5), Grupo 3 – Microdont (n=5). As imagens para análise micromorfométrica foram obtidas com uma lupa Opticam e as medidas determinadas com o software TSView versão 7.2.1.7. Os resultados obtidos foram submetidos ao teste de normalidade de Kolmogorov-Smirnov (KS). Foi realizada a Análise de Variânica (ANOVA) complementado com o teste “Post-hoc” de Student-Newman-Keuls (SNK). O nível de significância () foi de 5%. Resultados: As marcas Angelus e Jon não apresentaram diferenças significantes (p>0,05) e apresentaram valores menores que os nominais (2%). A Microdont apresentou uma variação significativa quando comparada as outras marcas (p<0,05) e maior em relação as medidas nominais (6%). Conclusão: As réguas endodônticas milimetradas com maior precisão em relação aos valores nominais foram a Angelus e JON. A régua Microdont foi a que apresentou maior variação, com valores acima dos nominais

Clareamento de dentes não-vitais com a técnica inside-outside: uma revisão crítica / Whitening non-vital teeth with the inside-outside technique: a critical review

O artigo apresenta uma revisão de literatura, com o intuito de explicar: a técnica de clareamento, os materiais utilizados, as contra-indicações, mecanismos da reabsorção radicular e o processo químico do clareamento de dentes não-vitais. A técnica clareadora em questão é um tratamento conservador, simples e que possui um alto índice de sucesso. O trabalho abordará, através de uma revisão crítica da literatura, quais são os materiais necessários e como é realizado o procedimento. As alterações de cor dos elementos dentários desvitalizados podem estar relacionadas à diversos fatores e, através da técnica do clareamento, é possível trazer de volta a autoestima do paciente e, consequentemente, uma melhor qualidade de vida

Mechanical properties of reciprocating thermally treated NiTi endodontic instruments / Propriedades mecânicas de instrumentos endodônticos de NiTi reciprocantes tratados termicamente

The aim of this study was to evaluate the flexibility, buckling resistance, dynamic cyclic fatigue resistance and roughness pattern of Reciproc R25 M-Wire (R25M), Reciproc Blue R25 (R25B) and WaveOne Gold Primary (WOGP) NiTi reciprocating instruments. Thirty-three R25M, 30 R25B e 30 WOGP, all with 25mm in length, were tested. The flexibility was determined by 45° bending tests according to the standard ANSI/ADA number 101 specification. To determine the buckling resistance an increasing axial load was applied to the instruments until the file underwent an elastic displacement of 1mm. A customized machine was used to perform the dynamic cyclic fatigue test measuring the time to fracture in a metallic stainless steel canal measuring 1.4 mm of diameter, 19 mm of total length, an angle of 86 degrees and 6 mm of curvature radius. The roughness was obtained using a profilometer. Results were analyzed using one-way ANOVA and Student-Newman-Keuls post-hoc test. Analysis were performed with the significance level (?) of 5%. The instruments presented the following order of flexibility: R25B > WOGP > R25M (P < 0.05); buckling resistance: R25M > R25B > WOGP (P < 0.05); and cyclic fatigue resistance: R25B > R25M > WOGP (P < 0.05). No differences were observed regarding the roughness pattern (P > 0.05). The R25B file presented superior flexibility and performance under fatigue tests. The R25M have higher buckling resistance. Instruments demonstrated similar characteristics of surface. 

Revascularization in a maxillary lateral incisor using bioceramic sealer: case report: Revascularização pulpar em incisive lateral com cemento biocerâmico: relato de caso

Revascularization is a regenerative endodontic dental procedure, which aims to stimulate the penetration of periradicular tissue inside the root canal, allowing vascularization of necrotic teeth, leading to a tissue repair and regeneration. Currently, Biodentine cement has been used to perform this procedure. The aim of this study was to report a clinical case about the revascularization of a maxillary lateral incisor with incomplete root formation using Biodentine. The patient, male, 10 years old, attended the multidisciplinary clinic of CEULP/ULBRA accompanied by the responsible, asymptomatic, reporting trauma to element 22, sensitivity and vertical percussion tests were performed with negative results. Through periapical radiography, incomplete root formation and a radiolucent area in the periapical region were observed. The revascularization technique was performed, aiming to stimulate the root formation. In the first session, instrumentation with K-type instruments at working length and intracanal medication were performed. After 15 days, the revascularization procedure was performed with a 25/0.02 K file led beyond the working length to stimulate periapical bleeding, so the canal was filled with blood up to the cervical third. Blood clotting was awaited, Biodentine was placed, and the definitive restoration was performed with composite resin. Follow-up up to 1 year and four months was carried out and the root development was observed. Thus, in the reported case, the revascularization technique proved to be efficient, allowing the continuity of the root formation a compromised tooth

Fatigue resistance of endodontic instruments manufactured in NiTi CM Wire and in conventional NiTi alloy with eletrochemical treatment

Objective: This study compared the fatigue behavior of endodontic instruments manufactured with conventional NiTi alloy electropolishing, RaCe (FKG Dentaire, LaChauxdeFonds, Switzerland), with instruments manufactured with NiTi CM ​​Wire subjected to thermomechanical treatment, in the manufacturing process, HyFlex CM (Coltène Whaledent, Cuyahoga Falls, Ohio, USA), both with similar geometry and dimensions in order to determine the influence of the manufacturing process in the fatigue resistance. Methods: The methodoly consisted of twenty HyFlex CM and RaCe instruments with D0 0.25 mm, taper 0.06 mm / mm, 25 mm length, both with triangular cross section. The fracture resistance was evaluated by static fatigue test, using a stainless artificial canal with 5mm of radius (86°), recording the time and calculating the number of cycles until fracture occurs (NCF). For statistical analysis the Student t test was used The fractured instruments surface was analyzed by SEM. Results: The NCF was significantly higher for HyFlex CM instruments in comparison with RaCe files (P˂0.05) being 1336% more resistant to fatigue. The analysis of the fractured surface by SEM showed ductile-kind morphological characteristics for both instruments and the absence of plastic deformation. Conclusion: HyFlex CM instruments present higher values ​​of NCF. Thus, it can be concluded that the thermal treatment to which these instruments with CM Wire alloy are submitted makes them more resistant to fracture than Race instruments manufactured with conventional NiTi alloy electropolishing

Mechanical Properties of Anatomic Finishing Files: XP-Endo Finisher and XP-Clean

<div><p>Abstract The aim of the present study was to evaluate the cyclic fatigue of two anatomic finishing files: XP-Endo Finisher and XP-Clean. Roughness pattern and the micro-hardness of the files were also assessed. Instruments were subjected to cyclic fatigue resistance measuring the time to fracture in an artificial stainless-steel canal with a 60° angle and a 5-mm radius of curvature. The fracture surface of all fragments was examined with a scanning electron microscope. The roughness of the working parts was quantified by using a profilometer and the micro-hardness test was carried out using a Vickers hardness tester. Results were statistically analyzed using a student´s t-test at a significance level of P < 0.05. Weibull analysis was also performed. XP-Endo Finisher presented significantly longer cyclic fatigue life than XP-Clean instruments (P<0.05). XP-Endo Finisher was able to withstand 1000% more cycles to fracture when compared to XP-Clean instruments. SEM visual inspection of the fracture surfaces revealed fractographic characteristics of ductile fracture in all tested instruments; wide-ranging forms of dimples were identified and no plastic deformation in the helical shaft of the fractured instruments was observed. When mean life was compared XP-Endo Finisher lasted longer than XP-Clean with a probability of 99.9%. XP-Endo Finisher instruments also exhibited significantly lower roughness than XP-Clean instruments (P<0.05). No differences in the micro-hardness was observed between the files (P>0.05). It can be concluded that XP-Endo Finisher instruments showed improved performance when compared with XP-Clean instruments, demonstrating higher cyclic fatigue resistance and lower roughness.</p></div