The effect of root canal preparation tapers on planktonic bacteria and biofilm reduction in the apical third: A correlative microtomography and microbiological laboratory study.

AIM: To evaluate the influence of different preparation tapers on the reduction in planktonic bacteria and biofilms of Enterococcus faecalis and Candida albicans in the apical third (4 mm) of the mesial roots of mandibular molars, correlating decontamination with canal shape. METHODOLOGY: After microtomography analysis for morphological standardization of the canals, 48 mandibular molar roots, each containing two canals (96 canals), were contaminated with E. faecalis and C. albicans and divided into four groups (n = 11) for canal instrumentation using ProDesign Logic 2 files with different tapers G (.03): # 25.03; G (.04): # 25.04; G (.05): # 25.05; and G (.06): # 25.06 and irrigation with 2.5% sodium hypochlorite. Four roots were examined under a scanning electron microscope (SEM) to qualitatively assess biofilm formation. Eight roots were used as the negative control group (samples were not contaminated). Bacteriological samples were taken exclusively from the apical third of the roots before and after chemical-mechanical preparation and bacterial counts were determined (CFU/mL). The final micro-CT scan was used to quantify the volume variation and unprepared canal area in the apical third. Statistical analysis was performed using the Kruskal-Wallis, Student-Newman-Keuls and Wilcoxon tests for analysis of microbiological data. anova and the Tukey or Games-Howell test were used for analysis of micro-CT data and Spearman's test for correlations (α = 5%). RESULTS: All groups showed a significant reduction in bacteria (p < .05), with no statistically significant difference between groups. There was no significant difference in per cent volume increase between groups. The unprepared area (Δ%) was affected by the file used (p = .026) and was significantly lower for G (.06) compared to G (.03). There was no statistically significant correlation among bacterial reduction, volume and unprepared area (p > .05). CONCLUSION: The different preparation tapers influenced root canal shaping in the apical third but did not improve decontamination in this region.

Instrumentation time and effectiveness of hand and rotary files in a prototyped second mandibular primary molar: A micro-CT study.

BACKGROUND: Eccentric instruments have been proposed as more effective and less time-consuming for endodontic instrumentation. AIM: To compare biomechanical outcomes of different instrumentation systems and time undertaken for instrumentation in resin prototypes. DESIGN: Sixty standardized prototypes of mandibular second primary molars were instrumented according to the following systems: K-files, ProTaper Next (PTN), XP-endo Shaper (XPS), XP-endo Finisher (XPF), XP-Clean (XPC), and Sequence Baby File (SBF; n = 10/each). Irrigation was performed with saline with simultaneous aspiration, and time spent was recorded. The prototypes were micro-CT-scanned before and after the instrumentation, and image sets were reconstructed and registered. Non-instrumented areas, accumulated debris, removed root material volume, and canal transportation were quantified. Data were analyzed through ANOVA, the Kruskal-Wallis test, and the Wilcoxon signed-rank test (α = 5%). RESULTS: K-files and SBF resulted in more instrumentation time (p < .05). SBF, XPC and PTN removed less root dentine (p < .05), but PTN left more untouched areas (p < .05). Accumulated debris were lower for XPC and SBF (p < .05). Canal transportation was similar among the groups. CONCLUSION: Rotary systems reduced instrumentation time, whereas SBF and XPC resulted in more conservative instrumentation, with less debris accumulation and non-instrumented areas. A dedicated paediatric endodontic system (SBF) outperformed eccentric instruments in terms of effectiveness.

Influence of conservative endodontic access cavities on instrumentation of oval-shaped straight root canals.

AIM: To evaluate the influence of the design of endodontic access cavities on the percentage of unprepared areas of canal walls and flexural fatigue of instruments activated by reciprocating movement in oval-shaped straight root canals of extracted teeth. METHODOLOGY: Forty-two mandibular incisors with oval canals were scanned by a microcomputed tomography (micro-CT) device for homogeneous selection and distribution of the samples. Then, the teeth were divided into two groups (n = 21) according to the design of access cavity being tested: ultraconservative endodontic access cavity (UltraAC) and traditional access cavity. The canals were accessed with the aid of a surgical microscope, instrumented with the WaveOne Gold Medium system and irrigated with 2.5% NaOCl and 17% EDTA. The unprepared areas of the canal wall were analysed by overlaying images before and after instrumentation and expressed as percentages. micro-CT data were analysed using t-test, Mann-Whitney and Wilcoxon tests. The endodontic instruments used during instrumentation were subjected to static flexural fatigue testing using an artificial stainless steel canal with a 60° angle of curvature and a radius of 5 mm, located 5 mm from the tip of the instrument. The instruments were activated until fracture occurred, and the time in seconds for the fracture was recorded using a digital timer. The number of cycles to fracture was calculated and analysed statistically. For flexural fatigue data, an anova test complemented by a Tukey range test was used. The significance level of 5% was used for all analyses. RESULTS: There was no significant difference between the groups related to unprepared areas by the instrument during canal preparation (p > .05). The difference in flexural fatigue resistance between the groups was not significant. CONCLUSION: The use of UltraAC did not interfere with the canal instrumentation of extracted mandibular incisors with straight and oval canals. There was no difference in the flexural fatigue resistance of the instruments in relation to access cavity design.

Analysis of the penetration of NaOCl 5.25% into dentinal tubules using different irrigation protocols: An ex vivo study.

The objective of the study was to investigate the 5.25% sodium hypochlorite (NaOCl) penetration into the dentinal tubules after different irrigation methods. Seventy canines were stained with 1% crystal violet and divided into groups (n = 20): GEC-EasyClean; GPUI-E1 Irrisonic ultrasonic insert; GXP-XP-Endo finisher; GPC-conventional irrigation and GNC-stained tooth without irrigation. Axial sections (16×) were assessed and irrigant penetration was quantified as a bleaching halo on the surface of the apical, middle and coronal third. In the apical third, GPUI promoted greater NaOCl penetration (p < 0.05). GXP was better than GEC (p < 0.05), as was GPC (p > 0.05). The GPUI and GXP groups were similar in the middle and coronal third (p > 0.05). GPUI and GXP showed better results than GEC (p < 0.05). GPUI was more effective in the apical third and like GXP in the cervical and middle third.

Deciduous Molars Complexity Anatomy Reveled by Computed Microtomography.

OBJECTIVE: The aim of this study was to analyze the internal morphology of deciduous molars through the use of computed microtomography in a sample from Rio de Janeiro. MATERIAL AND METHODS: Thirty maxillary and 30 mandibular deciduous molars (n = 60), divided in first and second primary molars, were scanned by computed microtomography. The teeth were evaluated for root number, root canals, Vertucci classification, root curvature, presence of lateral canals, furcation dentin thickness, structure model index (SMI), volume, and canal surface area. RESULTS: The results showed 100% of maxillary molars had three roots and Vertucci type I canal was more prevalent in this group. In the mandibular ones, type IV was more frequent in the mesial root and class I in the distal root and the cavo-interradicular canal occurred in 2 specimens. Dentin thickness in the furcation region measured 1.53 and 1.59 mm in the maxillary and mandibular, respectively. Volume and area parameters varied according to the evaluated canals and SMI demonstrated that all canals had a cylindrical shape. CONCLUSION: More detailed information about the internal anatomy of the primary molars has been described, which may help strategies in the preparation of these root canals.

Microtomographic Assessment of the Shaping Ability of the Hyflex CM and XP-endo Shaper Systems in Curved Root Canals.

OBJECTIVE: This study compared the shaping ability of the Hyflex CM and XP-endo Shaper rotary file systems in curved mesial canals of mandibular molars using micro-computed tomography. MATERIAL AND METHODS: Seventeen mesial roots of extracted first mandibular molars with two independent mesial canals were scanned before and after root canal preparation with the tested rotatory file systems. Each mesial canal from the same specimen was prepared with one of the two systems. The parameters analyzed were canal centering (transportation) for the cervical, middle, and apical segments, as well as for the entire canal (0-10 mm from the apex); and canal volume increase, canal surface area increase, and unprepared canal walls for two segments, 0 to 4 mm and 0 to 10 mm from the apex. RESULTS: There was no significant difference between both systems regarding canal centering (transportation), volume increase, and unprepared canal walls for the 0 to 10 mm segment (p> 0.05); however, a significant difference was observed for the 0 to 4 mm segment (p <0.01), where the Hyflex CM left 28.46% of unprepared walls and XP-endo Shaper left 13.26%. CONCLUSIONS: The shaping ability of the two tested rotatory file systems in mesial roots of first mandibular molars was similar for all parameters in all the segments evaluated, except for the 0 to 4 mm segment, where XP-endo Shaper left a smaller area of unprepared canal walls than Hyflex CM.

Effect of Ozone Gas on Removal of Airborne Particles.

OBJECTIVE: Airborne particles are one of the most important factors in the spread of infectious pathogens and must be monitored in healthcare facilities. Viable particles are living microorganisms, whereas non-viable particles do not contain microorganisms but act as transport for viable particles. The effectiveness of ozone in reducing these particles in a non-controlled room and a controlled cleanroom using high-efficiency particles air (HEPA) filter was analyzed in this study. MATERIALS AND METHODS: Viable particles and non-viable particles sized 0.5 and 5 µm were quantified before and after ozonation in two different health environments: non-controlled (group 1) and controlled area, which was associated with a HEPA filtering system (group 2). Active air sampling using a MAS 100 was used to count the number of viable particles, while the number of non-viable particles/m3 was obtained following the manufacturer's recommendations of the Lasair III 310C system. RESULTS: Our results of the viable particles counting were not quantifiable and analyzed using statistical tests. Both groups showed a slight tendency to reduce the number of viable particles after ozonation of the environmental air. A statistically significant reduction of non-viable 5 µm particles after ozonation was observed in both groups (G1: p = 0,009; G2: p = 0,002). Reduction in the non-viable 0.5 µm particles after ozonation was observed only in group 2, associated with the HEPA filter. In group 1, after ozonation, a significant increase in 0.5 µm particles was observed, probably due to the breaking of 5 µm particles by ozone gas. Our results suggest that ozone gas can break 5 µm particles and, when associated with a HEPA filter, increases its effectiveness in removing 0.5 µm particles. CONCLUSION: Considering that 5 µm particles are important in the air transport of microorganisms, their reduction in the environment can be a relevant parameter in controlling the dissemination of infections.

Microtomographic Evaluation of Canal Centralization and Dentine Removal after Canal Preparation with Two Rotary Systems: HyFlex EDM and ProTaper Next.

OBJECTIVE: This study compared the ProTaper Next (PTN; Dentsply Sirona, Tulsa, Oklahoma, United States) and HyFlex EDM (HEDM; Coltene/Whaledent AG, Alstätten, Switzerland) systems using micro-computed tomography (CT). MATERIALS AND METHODS: Twenty-one mesial roots classified as Vertucci's type IV from extracted mandibular first molars with curvatures between 20 and 40 degrees were selected. The teeth were scanned using a micro-CT before and after root canal preparation by both systems, applied to the same root, in alternating canals. The following parameters were analyzed: canal centering, apical transportation, root canal diameter/root diameter. RESULTS: No statistically significant differences between both systems were observed for any of the assessed morphological parameters (p > 0.05). All canals presented diameter enlargement of more than 40% in relation to root diameter in the cervical and middle segments. No statistically significant difference was noted between the HEDM and PTN groups. The wear percentage for the HEDM group in the cervical and middle thirds were 49.66 ± 8.65 and 46.48 ± 14.29, respectively, and 51.02 ± 11.81 and 45.48 ± 10.79 for the PTN group, respectively. CONCLUSION: Both systems displayed similar mandibular molar mesial canals preparation, with no differences noted for any of the assessed parameters. Both groups showed increased canal diameter in the cervical and middle thirds by more than 40%.

Shaping ability of two root canal instrumentation systems in oval-shaped canals: A microcomputed tomography study.

The objective was to evaluate the shaping ability of XP-endo Shaper and Mtwo systems in oval-shaped canals preparation by microcomputed tomography (micro-CT) along the entire canal. The volume, surface area and percentage of unprepared area were evaluated by image processing in entire canal and apical third (5 mm). Apical transportation and centring ability were evaluated at 3, 5 and 7 mm from the apex. Forty single-canal oval canines were paired in two groups (n = 20) according to the instrumentation system: XP-endo Shaper and Mtwo. The teeth were scanned by micro-CT before and after instrumentation, using a thermal vat at 37°C. The XP-endo Shaper system was more effective in the instrumentation of oval-shaped canals when compared to Mtwo system, resulting in greater volume increases and lower percentage of unprepared canals walls in apical region. Regarding apical transportation and centring ability, no statistical difference was observed.

Final Endodontic Irrigation with 2% Peracetic Acid: Antimicrobial Activity and Cytotoxicity.

OBJECTIVE: The aim of present study was to assess the cytotoxicity and antimicrobial efficacy of 2% peracetic acid (PAA) compared with 5.25% sodium hypochlorite (NaOCl) and 2% chlorhexidine (CHX). MATERIAL AND METHODS: For the cytotoxicity test, 100 µl of the tested solutions were added in 12 wells with ECV 304 endothelial cells in each group: NaOCl, CHX, and PAA, in addition to the control group. Each solution was evaluated after 24 hours of contact in four dilutions: 0.2, 0.1, 0.05 and 0.025 through mitochondrial function using MTT colorimetric assay. In the antimicrobial evaluation, 40 dentin blocks 5 mm in length and 0.2 g in weight were incubated with 400 µl of Enterococcus faecalis suspension for 21 days at 37°C. The contaminated samples were divided into three experimental groups within 5 minutes of contact: NaOCl group, CHX group, PAA group, as well as the positive control group. The specimens received treatment and were transferred to a tube with saline for serial dilution of the solution and seeding for isolation and colony forming unit (CFU) count. STATISTICAL ANALYSIS: The results obtained were expressed as mean (A570 nm) ± standard deviation (SD) and in a multiple linear regression model and multiple comparisons conducted. RESULTS: The antimicrobial evaluation revealed that the NaOCl and CHX groups showed a statistically significant difference compared with the control group (p < 0.001), while the PAA reduced only the CFU growth. It can be concluded that, among the agents tested, PAA expressed greater cell viability, followed by CHX and NaOCl. However, it did not show greater antimicrobial activity in vitro in the mature biofilm of Enterococcus faecalis.

Influence of the Chelating Solutions in the Resistance of Glass Fiber Posts to the Root Dentin.

OBJECTIVE: This study aimed to evaluate the influence of chelating agents (EDTA, citric acid and Tetraclean) on glass fiber posts adhesion to root dentin. MATERIALS AND METHODS: Forty mandibular premolars single canals, with complete apical root, straight, circular cross sections were selected, accessed and had the cervical third prepared with Gates-Glidden drills, then included in resin, instrumented with ProTaper Universal and the root canal obturation was carried out. After, the samples were randomly divided into 4 groups (n = 10) to test the final irrigation solutions: G1:17% EDTA; G2:10% citric acid; G3: Tetraclean and G4: saline solution (control). After 30 days of storage (36.5° C and 100% humidity), the post preparation was performed leaving 4 mm of apical endodontic filling. Then, a fiber-glass post previously selected was coated with ED Primer adhesive system and resin sealer Panavia, installed and stored for 24 hours at 37°C. The samples were subjected to a tensile test with a constant speed of 1 mm/min with 2000 Kgf. The results were analyzed with the ANOVA test. RESULTS: The statistical analyzes indicated no significant differences between the groups (p > 0.05). CONCLUSION: The type of chelating agent used in the final irrigation of the endodontic treatment did not influence the tensile strength of the fixation system used to sealer the glass fiber posts to the intracanal dentin.

Apical surgery as cystic lesion treatment for barodontalgia prevention: a case report / Cirugía apical como tratamiento de lesión quística para prevenir la barodontalgia: informe de caso

ABSTRACT Barodontalgia is not a pathology but a symptom of a subclinical oral problem that, although rare, may affect patients subjected to atmospheric pressure changes and have an influence on flights. This paper aims to discuss the clinical characteristics of pathologies related to the etiology of barodontalgia, as well as differential diagnoses, treatments, and prevention. This paper reports a case of a Brazilian air force officer who went to the Santos Dumont Air Force Dental Clinic reporting pain in the anterior maxillary during a flight. An endodontic treatment followed by periradicular surgery was performed, in order to quickly seal the bone lesion and to avoid new cases of barodontalgia. This work demonstrated a successful approach of a periradicular lesion solved by surgical treatment in order to avoid new cases of barodontalgia during flights. In addition, this paper highlights the importance of deepening knowledge on this event and the need for periodic oral and dental assessment, as well as conclusive treatment in aircrew members in order to prevent aircraft accidents.

ABSTRACT La barodontalgia no es una patología en sí misma, sino un síntoma de un problema oral subclínico que, si bien es poco frecuente, puede afectar a pacientes sometidos a cambios en la presión atmosférica y afectar la seguridad de los vuelos. Este artículo pretende analizar las características clínicas de las patologías relacionadas con la etiología de la barodontalgia, así como los diagnósticos diferenciales, los tratamientos y la prevención. Se presenta el caso de un agente de la fuerza aérea brasileña que acudió a la Clínica Dental de la Fuerza Aérea Santos-Dumont reportando dolor en el maxilar anterior durante un vuelo. Se realizó un tratamiento de endodoncia seguido de cirugía perirradicular, con el fin de sellar rápidamente la lesión del hueso y evitar nuevos casos de barodontalgia. Este trabajo describe un procedimiento acertado para una lesión perirradicular resuelta por tratamiento quirúrgico para evitar nuevos casos de barodontalgia durante los vuelos. Además, destaca la importancia de profundizar en el conocimiento sobre este evento y la necesidad de llevar a cabo no solo una evaluación bucodental periódica de los miembros de las tripulaciones, además de ofrecerles tratamientos definitivos, con el fin de prevenir los accidentes aéreos.

Contamination of gutta-percha cones in clinical use by endodontic specialists and general practitioners / Contaminación de los conos de gutapercha para uso clínico por parte de odontólogos y endodoncistas

ABSTRACT. Introduction: the present study evaluated the microbial contamination of gutta-percha cones proceeding from packages used clinically by endodontic specialists and general practitioners. Methods: two gutta-percha cones were selected from 30 original packages, already in clinical use, in dental clinics. The cones were transferred directly to test tubes containing thioglycolate broth and incubated at 37 °C for 21 days in aerobiosis. All tests were done in triplicate. Fractions proceeding from the tubes that presented turbidity were plated in CLED agar and Gram staining. Results: among the gutta-percha cone boxes tested, 9 (30%) showed bacterial contamination in the tested cones, 4 (13%) of those coming from general practitioners and 5 (17%) coming from specialists. There was no significant difference in the contamination of cones in relation to their origin (p>0,05). Conclusion: the results of the present study reinforce the need for both clinical dentists and endodontics specialists to implement a strict disinfection protocol before using gutta-percha cones, due to the frequency of contamination.

RESUMEN. Introducción: el presente estudio consiste en una evaluación de la contaminación microbiana de los conos de gutapercha procedentes de paquetes usados clínicamente por odontólogos generales y endodoncistas. Métodos: se seleccionaron dos conos de gutapercha de cada uno de 30 paquetes que estaban siendo utilizados en clínica dental. Los conos fueron llevados a tubos que contenían caldo de tioglicolato e incubados a 37 °C durante 21 días en aerobiosis. Todas las pruebas se realizaron por triplicado. Los fragmentos procedentes de los tubos que presentaban turbidez fueron tratados con agar CLED y tinción de Gram. Resultados: de las cajas de conos de gutapercha evaluadas, 9 (30%) presentaron contaminación bacteriana en los conos evaluados, 4 (13%) de los cuales provenían de odontólogos y 5 (17%) de endodoncistas. No hubo ninguna diferencia significativa en cuanto a la contaminación de los conos con respecto a su origen (p > 0,05). Conclusión: los resultados del presente estudio resaltan la necesidad de que tanto odontólogos como especialistas en endodoncia implementen un estricto protocolo de desinfección antes de usar los conos de gutapercha, dado que las contaminaciones son frecuentes.

Prevalence of dental caries in patients with intellectual disabilities from the Association of Exceptional Children's Parents and Friends of Southern Brazil / Prevalência da cárie dentária em pacientes com deficiência intelectual da Associação de Pais e Amigos das Crianças Excepcionais do Sul do Brasil

ABSTRACT Objective: This study was conducted to determine the prevalence and severity of dental caries, missing and restored teeth (DMFT) and the efficiency of oral health programs for patients with intellectual disabilities, from age 11 to 38, who attended at the Association of Exceptional Children's Parents and Friends (APAE) in Passo Fundo, southern Brazil. Methods: The prevalence of dental caries was assessed by DMFT in 109 patients. The mean and standard deviation were evaluated by One-way ANOVA with 5% significance level. Results: 47 of the evaluated students were female and 62 male, with moderate mental disability, Down syndrome, cerebral paralysis and epilepsy. The DMFT average was 3.93 for 11-14 years, 3.47 for 15-19 years, 4.74 for 20-30 years and 5.68 for the group 31-40 years. There were no significant differences among the DMFT index, gender and intellectual disability for the groups. Conclusion: Patients had acceptable oral hygiene within their limitations, suggesting that prevention and dental care program developed in APAE-PF/RS could be used as a model for health care for patients with intellectual disabilities in other institutions and other cities.

RESUMO Objetivo: Determinar a prevalência e a severidade da cárie dentária, ausências dentárias e restaurações pelo índice CPOD, tão bem como a eficiência dos programas de saúde bucal de pacientes com deficiência intelectual, com idades de 11 a 38 anos, que frequentavam a Associação de Pais e Amigos das Crianças Excepcionais-APAE Passo Fundo, Sul do Brasil. Métodos: A prevalência da cárie dentária foi avaliada pelo índice CPOD em 109 pacientes. A média e o desvio-padrão foram avaliados pela ANOVA unidirecional com nível de significância de 5%. Resultados: 47 dos estudantes avaliados eram do sexo feminino, e 62 do masculino, apresentando deficiência mental moderada, síndrome de Down, paralisia cerebral e epilepsia. A média do CPO-D foi de 3.93 para as idades de 11-14 anos, 3.47 para 15-19 anos, 4.74 para 20-30 anos e 5.68 para os pacientes com 31-40 anos. Não houve diferenças significativas entre o índice de CPOD, gênero e deficiência intelectual. Conclusão: Os pacientes apresentaram higiene bucal aceitável dentro das suas limitações, sugerindo que o programa de prevenção e tratamento odontológico desenvolvido no APAE-PF/RS poderia ser utilizado como modelo de atenção à saúde para pacientes com deficiência intelectual em outras instituições e outras cidades.

Apicificação com MTA para obturação de dente traumatizado: relato de caso / Apexification with MTA for traumatized tooth: a case report

Introdução: o tratamento de dentes jovens traumatizados requer atenção especial, devido à possível presença de ápice incompleto e paredes dentinárias delgadas, o que pode dificultar ou comprometer o tratamento endodôntico convencional. Faz-se necessária a realização de um procedimento para induzir a formação de uma barreira mineralizada, com o auxílio de materiais biocompatíveis, como o hidróxido de cálcio e o agregado trióxido mineral (MTA). Objetivo: relatar um caso clínico em que foi realizada apicificação, com tampão de MTA, em um incisivo lateral superior traumatizado. Conclusão: o uso de MTA como material obturador de dentes com ápice incompleto mostrou- se eficiente, pois permitiu resolução do caso com sucesso e a manutenção do dente na arcada, exercendo suas funções primárias quanto à estética e à mastigação.

Efetividade do ácido peracético na desinfecção rápida de cones de guta-percha e de Resilon expostos ao Enterococcus faecalis / Effectiveness of peracetic acid in rapid disinfection of gutta-percha and Resilon cones exposed to Enterococcus faecalis

Objetivo: o objetivo desse trabalho foi verificar a efetividade do ácido peracético a 2% na descontaminação rápida de cones de guta-percha e de Resilon, comparado ao hipoclorito de sódio e à clorexidina. Métodos: os cones de guta-percha e Resilon foram imersos por cinco minutos para contaminação em suspensão de Enterococcus faecalis, e divididos em grupos (n = 10): ácido peracético a 2% (um e três minutos); NaOCl a 5,25% (um e três minutos); clorexidina a 2% (um e três minutos). Após a realização dos protocolos em teste, os cones foram transferidos para tubos de ensaio contendo meio Enterococcosel® e, então, foram mantidos em estufa a 37º por 48 horas. Após o período de observação, os tubos foram avaliados e os que apresentam turvação do meio foram consideradas positivos. Resultados: os resultados demonstraram que o ácido peracético a 2% parece ser efetivo para a descontaminação de ambos os tipos de cone, de forma alternativa ao NaOCl a 5,25%, enquanto a clorexidina a 2% apresentou menor efetividade (p < 0,05). Conclusão: Ambas as soluções, ácido peracético a 2% e NaOCl a 5,25%, foram efetivas na descontaminação de cones de guta-percha ou de Resilon nos tempos testados.

Localização e tratamento do canal médio-mesial em raízes mesiais de molares inferiores û relato de dois casos / Location and treatment of middle-mesial canal in mesial roots of mandibular molars - two cases report

A morfologia da cavidade pulpar é complexa, e um exemplo dessa diversidade é um terceiro canal que pode ser localizado na raiz mesial dos molares inferiores, e que recebe o nome de canal médio-mesial. A taxa de ocorrência desse canal difere na literatura, mas essa é unânime em considerar que a ausência de seu manejo pode levar ao insucesso do tratamento. O objetivo do presente trabalho foi a realização de uma breve revisão de literatura e da apresentação de dois casos clínicos nos quais houve o tratamento do canal médio-mesial. Ao final, pode-se enfatizar a importância do conhecimento da anatomia, bem como da necessidade da correta inspeção do soalho da câmara pulpar para a localização e tratamento do canal médio-mesial, para assim, contribuir com o sucesso da terapêutica endodôntica...

The morphology of the pulp cavity is complex, and an example of this diversity is a third canal that can be located in the mesial root of mandibular molars, which is called the midmesial canal. The literature presents different data regarding the occurrence rate of this canal, but is unanimous that the absence of its management can lead to treatment failure. The objective of this study was to conduct a brief literature review and presentation of two cases of treatment of medium-mesial canal. At the end, one can emphasize the importance of knowledge of anatomy as well as the need for proper inspection of the floor of the pulp chamber to the location and treatment of middle-mesial canal, so as to contribute to the success of endodontic therapy...

Sistemas reciprocantes WaveOne e Reciproc e o preparo do canal radicular û revisão de literatura / Recirpoc and WaveOne reciprocating systems on root canal preparation û literature review

A Endodontia busca o constante aprimoramento de técnicas e sistemas de instrumentação que otimizem a limpeza e modelagem dos canais. Nos últimos anos, foram lançados no mercado os sistemas com o princípio de instrumentação com lima única, Reciproc e Wave One, que devido à cinemática e características morfológicas dos instrumentos, representam um novo conceito de preparo do canal. O presente trabalho de revisão buscou justificar o uso clínico desses sistemas, concluindo que, como em qualquer nova técnica, devem ser consideradas as vantagens e desvantagens dos instrumentos, além de ser necessário treinamento como forma de atingir melhor resultado no tratamento...

Endodontic science is constantly seeking to improve techniques and instrumentation systems for root canal cleaning and shaping. In this context, Reciproc and WaveOne, are two systems based on single file instrumentation technique principle. Due to the kinematics and morphological characteristics, these instruments represent a new concept of root canal preparation. The present review sought to justify these systems on clinical usage. Thus it can be concluded that such as any new technique, advantages and disadvantages should be considered and in addition proper training is required in order to achieve better treatment outcomes...

Desgaste dos instrumentos K3 e Protaper após simulação de uso clinico em canais curvos / Wear of K3 and ProTaper files after simulated clinical use in curved canals

Objetivo: Avaliar o desgaste, após simulação de uso clínico, de instrumentos K3 (SybronEndo, Orange, CA, EUA) e ProTaper (Dentsply-Maillefer, Tulsa, Oklahoma, EUA) em 46 raízes mesiovestibulares de primeiros molares superiores humanos, recém-extraídos e com angulação média de 40º. Métodos: Os dentes foram divididos em: a) K3 (SybronEndo, Orange, CA, EUA) (com bandas radiais) e b) ProTaper (Dentsply-Maillefer, Tulsa, Oklahoma, EUA) (sem bandas radiais). Os instrumentos foram avaliados em microscopia eletrônica de varredura antes do primeiro uso, para visualização de defeitos de fabricação, após 7 e 13 ciclos de instrumentação nos canais. A instrumentação foi realizada de acordo com as recomendações do fabricante, sendo K3 (SybronEndo, Orange, CA, EUA) e Protaper (Dentsply-Maillefer, Tulsa, Oklahoma, EUA). Os critérios para avaliação de desgaste foram: defeitos (estiramento, encurtamento/ inversão das espiras, presença de crateras), trincas oblíquas e fratura. Após a avaliação em microscopia eletrônica de varredura antes do uso, foram constatadas em todos os instrumentos, farpas metálicas na crista das espiras e ranhuras oblíquas provenientes do processo de usinagem. Resultados: Após sete usos, no sistema K3 (SybronEndo, Orange, CA, EUA), todos os instrumentos apresentaram defeitos nos ângulos de corte e, 25/08 e 25/10 apresentaram trincas oblíquas no corpo da parte ativa levando à fratura dúctil desta última após o oitavo uso. No sistema ProTaper (Dentsply-Maillefer, Tulsa, Oklahoma, EUA), em sete usos, além de defeitos nos ângulos de corte, os instrumentos também apresentaram trincas, e a fratura rúptil ocorreu em F3 no 13º uso. Ao final do preparo foram observadas crateras ao longo da parte ativa dos instrumentos. Conclusão: Na análise final, foi evidenciado que os sistemas se equivalem quanto aos defeitos encontrados, independentemente do desenho da parte ativa, sendo proporcionais à quantidade de ciclos de uso, e que estes defeitos podem funcionar como...

Objective: To assess wear, after simulated clinical use of K3 (SybronEndo, Orange, CA, EUA) and ProTaper files (Dentsply-Maillefer, Tulsa, Oklahoma, EUA) in 46 mesiovestibular roots of human maxillary first molars, recently extracted and with mean angulation of 40º. Methods: The teeth were divided as follows: a) K3 (SybronEndo, Orange, CA, EUA) (with radial bands) and b) ProTaper (Dentsply-Maillefer, Tulsa, Oklahoma, EUA) (without radial bands). The files were assessed by scanning electronic microscopy before first use to visualize fabrication defects, and after 7 and 13 cycles of debridement in the canals. Debridement with files K3 (SybronEndo, Orange, CA, EUA) and ProTaper (Dentsply-Maillefer, Tulsa, Oklahoma, EUA) was performed in accordance with the manufacturers' recommendations. The criteria for wear assessment were: defects (stretching, shortening/spiral inversion, presence of craters), oblique cracks and fracture. After assessment by SEM and before they were used, metal barbs on the crest of the spirals and oblique scratches due to the machining process were found in all the files. Results: In the K3 system (SybronEndo, Orange, CA, USA), after being used seven times, all the instruments showed cutting angle defects, and 25/08 and 25/10 had oblique cracks in the body of the active part leading to ductile fracture after being used for the eighth time. In the ProTaper system (Dentsply-Maillefer, Tulsa, Oklahoma, USA), after being used seven times, in addition to cutting angle defects, the files also presented cracks, and ruptile fracture occurred in F3 during use for the thirteenth time. At the end of preparation, craters were seen along the active part of the files. Conclusion: In the final analysis, it was seen that the system are equivalent with regard to the defects found, irrespective of the active part design, being proportional to the number of cycles of use, and these defects could act as points of greater fragility, favoring fracture.

Avaliação microtomográfica de canais mesiais de molares inferiores preparados com sistemas rotatórios e reciprocantes / Computed microtomography analysis of mesial canals of mandibular molars prepared with rotary and reciprocating systems

O objetivo do presente trabalho foi avaliar, em microtomografia computadorizada (µCT), o preparo de canais de molares inferiores com diferentes sistemas acionados a motor. Foram selecionadas 58 raízes mesiais patentes, de diâmetro anatômico correspondente a #10. Para a avaliação em µTC, um anel de aço inoxidável foi confeccionado nos moldes do suporte para amostra do microtomógrafo, para que servisse de fôrma para a inclusão das raízes em resina Duralay, a fim de padronizar a posição do espécime no escaneamento inicial e final. Os canais foram preparados com os sistemas Reciproc R25 (n=16); WaveOne Primary File (n=16); Twisted File (n=14), e HyFlex (n=12). Após serem escaneados, foram reconstruídos tridimensionalmente e avaliados quantitativamente quanto à variação de volume (mm3), área de superfície (mm2) e structure model index (SMI). Foi, ainda, realizada a avaliação qualitativa das seções transversais por terço e por quadrante (MV, ML, DV, DL), sendo avaliado o toque de paredes. Os dados paramétricos foram analisados estatisticamente pelos testes ANOVA e t para amostras pareadas (α=5%). Não foi observada diferença estatística nos parâmetros quantitativos avaliados para Reciproc (142,77 ± 76,75; 42,22 ± 19,22; e 14,68 ± 17,69, respectivamente); WaveOne (105,09 ± 64,82; 29,54 ± 19,21; 14,81 ± 9,10, respectivamente); Twisted File (111,83 ± 43,09; 33,31 ± 18,40; 9,16 ± 6,57, respectivamente), e HyFlex (151,74 ± 149,37; 43,08 ± 41,44; 10,80 ± 8,52, respectivamente) (p=0,423). Dentro de cada grupo, foi observada diferença significante entre os resultados pré e pós-operatórios. O teste não paramétrico de Kruskal Wallis foi aplicado para a avaliação relativa ao toque de paredes. Foi observado que o sistema HyFlex apresentou a maior porcentagem de toques (82,3 ± 13,1), seguido por Reciproc (81,3 ± 16,9), Twisted File (78,3 ± 14,4) e, por fim, WaveOne (76,9 ± 21,7) (p>0,05). Em relação aos terços não foi observada diferença significativa (p=0,424). Os resultados da avaliação dos quadrantes intergrupo não demonstraram diferenças, porém indicaram tendência do preparo em direção à parede distal no terço cervical. Ao final, pôde-se concluir que os sistemas testados se equivalem quanto ao preparo de canais mesiais de molares inferiores; porém, nenhuma das técnicas foi capaz de tocar completamente em todas as paredes do canal radicular(AU)

The aim of this work was to analyze, in X-ray computed microtomography (µCT), the root canal preparation of mandibular molars with different engine driven systems. 58 mesial roots were selected, of anatomic diameter corresponding to #10. For the analysis in µTC, a stainless steel ring was manufactured in the same shape as the brace for µCT sampling, in order to serve as a mold to insert the roots in Duralay resin, so as to standardize the position of the specimen in the initial and final scanning. The canals were prepared with the Reciproc R25 (n=16), WaveOne Primary File (n=16), Twisted File (n=14) and HyFlex (n=12) systems. After being scanned, they were three-dimensionally reconstructed and quantitatively evaluated as regards the variation of volume (mm3), surface area (mm2) and structure model index (SMI). In addition, the qualitative evaluation of the cross sections by third and by quadrant (MV, ML, DV, DL) was carried out, along with the wall touching evaluation. The parametric data were statistically analyzed by ANOVA and t-tests for paired samples (α=5%). No statistical difference was observed in the qualitative parameters evaluated for Reciproc (142.77 ± 76.75; 42.22 ± 19.22; and 14.68 ± 17.69; respectively), WaveOne (105.09 ± 64.82; 29.54 ± 19.21; 14.81 ± 9.10; respectively), Twisted File (111.83 ± 43.09; 33.31 ± 18.40; 9.16 ± 6.57; respectively) and HyFlex (151.74 ± 149.37; 43.08 ± 41.44; 10.80 ± 8.52) (p=0,423). Significant difference was observed within each group between the pre- and post-results. The Kruskal-Wallis non-parametric test was applied for the evaluation as regards root canal wall touching. At the end, we observed that the HyFlex system presented the highest touching rate (82.3 ± 13.1), followed by the Reciproc (81.3 ± 16.9), Twisted File (78.3 ± 14.4) and, finally, WaveOne (76.9 ± 21.7) systems (p>0.05). As for the thirds, was not observed any significant difference (p=0.424). The results of the evaluation in the intergroup quadrants did not show any difference; however, they showed that there was a preparation trend towards the distal wall in the cervical third. At the end, it can conclude that the systems tested are equivalent as regards the preparation of mesial canals of mandibular molars, but none of the techniques was capable of fully touching all root canal walls(AU)