Bypass de instrumento endodôntico fraturado: relato de caso / Bypass of a fractured endodontic instrument: case report

Introdução: Mesmo com toda evolução tecnológica desses instrumentos, com o desenvolvimento das limas de liga de níquel-titanio (NiTi) e sistemas mecanizados, as fraturas podem ocorrer durante o preparo químico/mecânico. Existem três abordagens mais regulamente aplicadas para solucionar essa intercorrencia: tentativa de remoção do instrumento com ultrassom, tentativa de ultrapassálo (bypass) ou a obturação do segmento. Objetivo: Relatar um caso da técnica de bypass em instrumento fraturado no canal radicular. Descrição do caso: Paciente, sexo feminino, 47 anos, brasileira, sem condições sistêmicas associadas, foi encaminhada à clínica do Curso de Odontologia da UNIFENAS, Divinópolis, Minas Gerais, Brasil, para resolução de fratura de instrumento no canal mésio- vestibular do primeiro molar superior direito (16). Optou-se pelo tratamento pela técnica de bypass, que envolveu as seguintes etapas: anestesia, abertura, utilização de lima C-Pilot #08 para ultrapassar o instrumento fraturado, odontometria, escalonamento regressivo a partir da lima k#20, desinfecção com hipoclorito de sódio 5%, medicação com hidróxido de cálcio por 21 dias, agitação da substância irrigadora e obturação dos canais radiculares. Conclusão: O bypass ao instrumento é uma técnica conservadora, eficaz e uma solução adequada em casos de fratura de limas endodônticas dentro dos canais radiculares. Essa técnica visa preservar o máximo possível da estrutura dental original, evitando procedimentos mais invasivos.(AU)

Introduction: Even with all technological evolution of these instruments, with the development of nickel-titanium alloy (NiTi) files and mechanized systems, fractures can occur during chemical/mechanical preparation. There are three most commonly applie to resolve this complication: attempting to remove the instrument with ultrasound, attempting to bypass it, or obturating the segment. Objective: To report a case of bypass technique in fractured instrument in the root canal. Case description: A 47-year-old female patient from Brazil, with no associated systemic conditions, was referred to the clinic of the Dentistry Course at UNIFENAS, Divinópolis, Minas Gerais, Brazil, for resolution of an instrument fracture in the mesio-vestibular canal of the right upper first molar (16). Treatment was performed using the bypass technique, which involved the following steps: anesthesia, opening, use of a C-Pilot #08 file to bypass the fractured instrument, odontometry, regressive scaling from the k#20 file, disinfection with 5% sodium hypochlorite, medication with calcium hydroxide for 21 days, agitation of the irrigating substance and root canal filling. Conclusion: Instrument bypass is a conservative, effective technique and an adequate solution in cases of endodontic file fracture within root canals. This technique aims to preserve as much of the original tooth structure as possible, avoiding more invasive procedures.(AU)

Effect of contracted endodontic access cavity and root canal preparation by One Curve on danger zone of mesial root canal in mandibular first molars / 口腔疾病防治

Objective @#To explore the influence of a contracted endodontic access cavity on the risk of canal transportation in the danger zone of the mesial root canal of mandibular first molars (MFMs) using a one-curve preparation system, and to provide an experimental basis for the clinical selection of a better pulp approach.@*Methods@#Twenty MFMs extracted for severe periodontal disease that met the inclusion criteria, including intact coronal roots, mesial roots with two separate root canals, mesiobuccal canal (MB) and mesiolingual canal (ML), and a curvature of 0° to 20°, were selected. Subsequently, these MFMs were randomly divided into two groups based on the endodontic access design, including the traditional endodontic access cavity (TEC) group and the contracted endodontic access cavity (CEC) group. In the TEC group, the pulp chamber roof of the tooth was completely removed, while in the CEC group, the pulp chamber roof and peri-cervical dentin were preserved as much as possible. Then, the One Curve single file was adopted to conduct root canal preparation. Next, cone beam computed tomography (CBCT) was performed on extracted teeth before and after preparation, and the measurement sections were located at 0-7.0 mm below the root bifurcation of the mesial root canal at 1 mm intervals. The minimum wall thickness on the mesial and distal aspect of the root canal was measured in each section.@* Results @# ① Prepreparation CT measurements of 20 MFMs showed that the danger zone in the range 0-4 mm under root bifurcation, a mean thickness of 1.18 mm on the mesial aspect of the MB root canal and 1.08 mm on the distal aspect. The mean thickness of the ML root canal was 1.28 mm on the mesial aspect and 1.07 mm on the distal aspect. ② Compared with that of the traditional endodontic access cavity, no significant difference in the decrease of wall thickness was observed in the danger zone of mesial root canal of MFMs in the contracted endodontic access cavity (t = 1.319，P = 0.19). ③ In the mesiobuccal canal, compared with the apical transportation of the traditional endodontic access cavity, which tends to be more mesial side, the apical transportation of contracted endodontic access cavity tends to the distal side. In the mesiolingual canal, both apical transportation groups tended to be on the distal side. @*Conclusion @# When using the One Curve file, compared with traditional endodontic access, the contracted endodontic access cavity based on the minimally invasive concept does not increase the risk that the mesial root canal of mandibular first molars is transported.

Development and application of a heart failure-specific information platform / 中华医学科研管理杂志

Objective:In this study, the application value of a specific information platform in heart failure was explored.Methods:We constructed five modules of information platform based on clinical needs, including user interface, patient management interface, follow-up platform, data processing interface and system management. By making good use of the platform, a database of heart failure was established and quality-controlled to realize the management of chronic heart failure, and prepare database for possible clinical research.Results:More than 3 000 patients with heart failure had been registered in the heart failure special disease platform. Long-term out-of-hospital management of cerfain patients with heart failure was conducted through intelligent information means. High-quality heart failure data were obtained and translated into clinical results.Conclusions:Long-term out-of-hospital management of patients with chronic heart failure can be realized through the special disease information platform, and high-quality evidence-based medical data can be obtained. Besides, the platform provides theoretical basis and data support for evaluation system of prognosis of heart failure, provides theoretical basis and data support for improving medication and surgical treatment plans and comprehensive management system of patients with heart failure.

Dose reconstruction of volumetric modulated arc therapy for nasopharyngeal carcinoma based on log files and CBCT / 中华放射肿瘤学杂志

Objective:To reconstruct the dose of nasopharyngeal carcinoma and verify the results of the whole-process radiotherapy plan based on log files and cone beam CT (CBCT).Methods:A total of 15 patients with nasopharyngeal carcinoma who received volumetric modulated arc therapy (VMAT) with Halcyon accelerator in the Cancer Center of Union Hospital, Tongji Medical College, Huazhong University of Science and Technology from February to September 2022 were retrospectively selected. Log files and CBCT for all fractionated radiotherapy were recorded. The errors of monitor unit (MU), gantry angle, and multi-leaf collimator (MLC) leaf position per control point were analyzed. The adaptive CT (aCT) were generated according to CBCT and planned CT (pCT) using a commercial software Velocity TM, and the similarities among aCT, pCT and CBCT were analyzed. The original plan was modified from the log files and imported into the treatment planning system to calculate the delivered dose on the corresponding fractionated aCT to reconstruct the fractionated dose. And all the reconstructed doses were mapped back to pCT to obtain the cumulative dose. Theγpass ratios with criteria of 2 mm/2% and 2 mm/3% and the dose differences between the planned dose and the cumulative dose in the planning target volume (PTV) and organs at risk (OAR) were compared. Results:The root mean square (RMS) and the 95th percentile of the errors of MU, gantry angle and MLC leaf position errors were within an acceptable range. The aCT generated by Velocity TM had the anatomical structure of CBCT and the resolution, contrast, noise characteristics of pCT, which could be directly used for dose calculation. Compared with the planned dose, the changes of V 70 Gy of nasopharyngeal primary tumor (PTV nx), V 68 Gy of cervical glands (PTV nd) and V 60 Gy of planning target volume (PTV1) were -0.88%±1.91%, -2.99%±2.99% and -0.63%±0.93%, respectively, and V 40 Gy of parotid gland was increased to 2.65%±2.63%. Cumulative dose showed different degrees of PTV dose decrease ( P<0.05) and parotid dose was increased ( P<0.05). The γ pass ratio (2 mm/3%) between the cumulative dose and planned dose was 97.3%±2.7% and >95.0% in 86.7% of patients. Conclusions:Based on the log files and CBCT, the whole-process dose reconstruction of nasopharyngeal carcinoma patients can be carried out. According to the results of dose reconstruction, the radiotherapy effect of the target area and OAR can be quantitatively evaluated. In the case of high dose coverage and conformity of the original plan, the reconstruction results show that the cumulative dose coverage of the target area is decreased, whereas that of the parotid gland is increased.

Comparative Evaluation of Efficacy of Three Single File Retreatment Systems for Removal of Gutta Percha and Assessment of Root Canal Transportation - An In Vitro Study

Background: In comparison to multiple file systems, recent advancements in single file retreatment systems had reduced the working time and ease of operation for clinicians. Aim: To compare the efficacy of retreatment systems compared with hand instrumentation, by evaluating their removal efficacy, time required for retreatment and assessment of canal transportation. Methods and Material: Forty premolars were instrumented using ProTaper Gold gold files. Post instrumentation, scan was taken, obturated using warm vertical compaction technique, and stored in artificial saliva for three months and randomly divided into four groups for retreatment. Hand instrumentation (Hi), Neoniti (Nn), Mtwo R (Mt), WaveOne Gold (Wg). Post retreatment, scan was taken. Teeth were sectioned longitudinally and photographed under the stereomicroscope. Retreatment time was recorded, and canal transportation was calculated. Statistical Analysis: The results were analyzed using one?way analysis of variance (ANOVA) followed by Tukey’s post hoc test at 95% confidence level. Results: The retreatment time was significantly longer in the Hi group. Within the test groups, a significantly longer time has been taken by Wg (p < 0.05) compared to Mt and Nn. There was no difference in the canal transportation between the single file systems at 3 mm, 6 mm and 9 mm from the apex, there was statistically significant higher transportation for the Hi group at 9 mm from the apex (p < 0.05). Conclusions: All techniques were effective in removal of filling material with minimal canal transportation. Wg system was shown to increased time compared to Nn and Mt systems. Hi group was slowest with maximum canal transportation at 9 mm from the apex.

Dificultades en la identificación de cadáveres y restos óseos por Odontología Forense en Costa Rica: Análisis de 165 autopsias / Difficulties in the identification of corpses and skeletal remains by Forensic Odontology in Costa Rica: Analysis of 165 autopsies

Resumen Introducción: En Costa Rica la elaboración del expediente odontológico o ficha clínica no se realiza de manera habitual en todos los pacientes como ocurre en muchos países donde es exigido por ley. La realización del expediente únicamente está normada en el Código de Ética del Colegio de Cirujanos Dentistas de Costa Rica, es decir que no realizarlo se considera una falta ético-disciplinaria con pocas repercusiones para la persona profesional; sin embargo, tiene consecuencias graves en los esfuerzos para identificar a un ser humano. Este estudio tiene como propósito describir el impacto de la ausencia o la mala calidad de datos odontológicos antemortem en los casos de identificación realizados por la Unidad de Odontología Forense del Departamento de Medicina Legal en un período de casi ocho años (2015-2022). Materiales y métodos: Se realizó una revisión detallada en la base de datos del Sistema de Medicina Legal (SIMEL) del Departamento de Medicina Legal del Organismo de Investigación Judicial de la totalidad de solicitudes de interconsulta de la Sección de Patología Forense desde enero de 2015 hasta agosto de 2022. La información recopilada fue tabulada en Excel e incluyó tanto los resultados del análisis pericial como las características de la información antemortem disponible. Resultados: El análisis de los datos permitió determinar que en un período de casi 8 años se realizaron 165 valoraciones con fines de identificación, de las cuales se identificaron positivamente 51 individuos, 9 casos presentaron información insuficiente y 105 no contaban con expediente odontológico. Conclusiones: el expediente odontológico completo es indispensable para lograr una identificación positiva, un expediente incompleto o inexistente anula la posibilidad de identificar a un ser humano. La necesidad de contar con legislación que convierta la realización y preservación de los expedientes odontológicos de forma obligatoria con fines de identificación es necesaria en Costa Rica.

Abstract Introduction: In Costa Rica the elaboration of dental records or clinical files is not performed routinely in all patients as it is required by law in many countries. The completion of the dental record is only regulated by the Code of Ethics of the Colegio de Cirujanos Dentistas de Costa Rica (Board of Dental Surgeons of Costa Rica), which means that failure to do so is considered an ethical-disciplinary offense with few consequences for the professional; however, it has serious consequences in the efforts to identify a person. This study aims to describe the impact of the absence or poor quality of antemortem data in identification cases performed by the Forensic Odontology Unit of the Department of Legal Medicine over a period of almost eight years (2015-2022). Materials and Methods: A detailed review was performed in the database of the Forensic Medicine System (SIMEL) of the Legal Medicine Department of the Judicial Investigation Organism of the totality of interconsultation requests of the Forensic Pathology Section from January 2015 to August 2022. The information collected was tabulated in Excel and included both the results of the expert analysis and the characteristics of the available antemortem information. Results: The analysis of the data made it possible to determine that in a period of almost 8 years 165 assessments were carried out for identification purposes, of which 51 individuals were identified, 9 cases presented insufficient information and 105 had no dental files. Conclusions: A complete dental record is indispensable for a positive identification; an incomplete or non-existent record nullifies the possibility of identifying a human being.

Clinical Management of Intra-Pulp Canal Broken Endodontic Files in Primary Teeth: Literature Review / Manejo clínico de las limas endodónticas fracturadas dentro del conducto pulpar en dientes primarios: Revisión de la literatura

ABSTRACT: Fracture of an endodontic file inside a primary root canal is a rare but critical complication during the pulpectomy treatment, because the mechanical obstruction impedes the optimal cleaning and obturation of the pulp canal, compromising seriously the clinical outcome. This accidental event is mainly associated with over-use and excessive torque of intracanal files. Most clinicians opt to proceed with the extraction of the affected tooth followed by a space maintainer placement. Other practitioners attempt the non-surgical retrieval of the separated fragment through available proven techniques in permanent teeth; however, these methods may involve significant damage to the tooth and surround tissues. On the other hand, preservation of the metallic fragment might affect the treatment prognosis and interfere with the physiological root resorption.

RESUMEN: La fractura de una lima endodóntica dentro de un conducto radicular primario es una complicación rara aunque critica durante el tratamiento de pulpectomía, debido a que la obstrucción mecánica impide la limpieza y obturación óptimas del conducto pulpar, comprometiendo seriamente el resultado clínico. Este evento accidental está principalmente asociado con el sobreuso y torque excesivo de las limas dentro del conducto. La mayoría de los clínicos optan por realizar la extracción del diente afectado, seguido por la colocación de un mantenedor de espacio. Otros practicantes intentan la remoción no quirúrgica del fragmento separado a través de técnicas disponibles probadas en dientes permanentes; sin embargo, estos métodos pueden causar daños significativos al diente y tejidos circundantes. Por otra parte, la preservación del fragmento metálico puede afectar el pronóstico del tratamiento e interferir con el proceso de reabsorción radicular fisiológico.

Thoughts on Construction of Information System of Medical Device Variety Archives / 中国医疗器械杂志

OBJECTIVE@#Thinking on the construction of the medical device type archives information system.@*METHODS@#This paper introduces the concept and significance of medical device variety archives, and puts forward the overall construction idea and system framework of medical device variety archives by analyzing its construction difficulties.@*RESULTS@#Considering the long-term nature and complexity of the construction of medical device variety archives, the system can be constructed in accordance with the three steps of system building, platform building and data management, and the overall technical architecture can be designed from the eight aspects of user layer, business application layer, application support layer, data resource layer, infrastructure layer, security, standards and operation and maintenance management.@*CONCLUSIONS@#Architecture design is the foundation of system construction, and its design rationality is very important for the success of system construction. The architecture design proposed in this study has a certain reference role for promoting the construction of medical device variety archives management system.

Research on Registration System of Medical Device Master Files in China / 中国医疗器械杂志

The registration system of medical device Master Files is established to solve the problem that the outsourcing suppliers are not willing to cooperate with the device applicants in the process of providing medical device application documents. After a brief introduction of Master Files systems established by foreign regulatory agencies, this article focuses on the research of establishing a medical device Master Files registration system in China. The results show that the establishment of Chinese Master Files registration system can both improve the standardization and convenience of outsourcing activities of medical devices, and satisfy the needs of the development of medical device industry and regulatory system. At the same time, the probability of additional risk caused by the implementation of the system is low. Therefore, it is expected that the benefits of the system to promote public health outweigh the potential risks, which demonstrates that establishment of the system has important application values.

Comparative Analysis of Three Massive Medical Image Storage Technologies / 中国医疗器械杂志

Nowadays, the massive medical data have already influenced the information construction in medical institutes, so it is not enough to solely rely on traditional local storage system to solve the problems like the read/write speed, visualization, and economy brought about by the massive data. Furthermore, various medical cloud services have been developed at home and abroad that patients' medical data can be shared through all medical institutes on the cloud, which makes a higher demand on the transmission speed of the medical data. This article analyzes from multiple aspects like high availability and costs by performing a medical image transmission speed test on the three mainstream storage technologies to provide an optional storage system for future medical image big data in the access process. The experimental result shows that it can be found that in the process of accessing medical image big data, the access speed and performance of object storage system is better than those of the existing local storage systems. However, with comprehensive consideration, it is recommended that the distributed file storage system like HDFS be the first choice for the storage system of the medical images.

Effect of treatment with sunflower oil and in combination with pomegranate and plum sauce on the chemical, microbiological and sensory properties of marinated Carp fillets (Cyprinus carpio) / Efeito do tratamento com óleo de girassol e em combinação com molho de romã e ameixa nas propiedades químicas, microbiológicas e sensoriais de filetes de carpa marinados (Cyprinus carpio)

ABSTRACT: The effect of sunflower oil (SO), sunflower oil-pomegranate sauce (PS1) and sunflower oil-plum sauce (PS2) on shelf life of marinated carp fillets was investigated in terms of sensory evaluation, chemical (peroxide value (POV), thiobarbituric acid (TBA), free fatty acids (FFA), total volatile basic nitrogen (TVB-N) and pH), and microbiological properties (Total viable count (TVC), Escherichia coli, Total coliform, Staphylococci/Micrococci, Salmonella spp.) during 30 days of storage. Proximate composition, which includes total crude protein%, fat%, moisture% and ash% of fresh carp fillets before marination process was analyzed and found 18.69±0.86, 4.08±0.19, 74.33±0.63 and 2.17±0.45, respectively. Sensory evaluation analysis showed that total appearance, odor-taste and texture scores decreased during storage. TVB-N significantly increased in all group after 1 month of storage (P<0.05). At the end of storage, the lowest TBA value (1.38 mg MA/kg carp fillet) was determined in the PS1 group. During storage, the highest POV value was observed in the control group (8.49 mEq O2/kg) compared to other groups. Initial TVC of 1.5 log CFU/g, 1.7 log CFU/g and 1.8 log CFU/g increased to 3.7 log CFU/g, 2.9 log CFU/g and 3.2 log CFU/g in SO, PS1 and PS2 groups, respectively. Results showed that the shelf life of marinated carp fillets treated with sunflower oil and in combination with pomegranate and plum sauce was more than 1 month.

RESUMO: O efeito do óleo de girassol (SO), molho de óleo de girassol-romã (PS1) e molho de óleo de girassol-ameixa (PS2) na vida útil de filetes de carpa marinados foi investigado em termos sensorial, químico (valor de peróxido (PV), ácido tiobarbitúrico) (TBA), ácidos graxos livres (AGL), nitrogênio básico volátil total (TVB-N) e pH) e propriedades microbiológicas (contagem viável total (TVC), Escherichia coli, coliforme total, estafilococos/Micrococos, Salmonella spp.). Durante 30 dias de armazenamento. A composição aproximada, que inclui % de proteína bruta total, % de gordura, % de umidade e % de cinzas de filés de carpa frescos antes do processo de marinação foi analisada e encontrada 18,69 ± 0,86, 4,08 ± 0,19, 74,33 ± 0,63 e 2,17 ± 0,45, respectivamente. A análise sensorial mostrou que os escores totais de aparência, odor e sabor diminuíram durante o armazenamento. TVB-N aumentou significativamente (P <0,05) em todos os grupos após 1 mês de armazenamento. No final do armazenamento, o menor valor de TBA (1,38 mg MA / kg de filé de carpa) foi determinado no grupo PS1. Durante o armazenamento, o maior valor de POV foi observado no grupo controle (8,49 mEq O2/kg) em comparação com outros grupos. O TVC inicial de 1,5 log CFU/g, 1,7 log UFC/g, 1,8 log CFU/g aumentou para 3,7 log CFU/g, 2,9 log CFU/g, 3,2 log CFU/g nos grupos SO, PS1 e PS2, respectivamente. Os resultados mostraram que a vida útil dos filés de carpa marinados tratados com óleo de girassol e em combinação com molho de romã e ameixa era superior a um mês.

Avaliação das propriedades físico-químicas de instrumentos reciprocantes de níquel-titânio tratados termicamente / Evaluation of the physicochemical properties of heat-treated nickel-titanium reciprocating instruments

Os instrumentos endodônticos de níquel-titânio acionados a motor foram desenvolvidos para se obter um preparo químico-mecânico mais rápido e seguro, no entanto, esses instrumentos apresentam como desvantagem o risco de fraturar durante o seu uso. Diante disso, os fabricantes têm desenvolvido mudanças no design dos instrumentos, nos acabamentos das ligas e na cinemática de uso, pois são características que contribuem para que as fraturas aconteçam. O objetivo deste estudo foi avaliar e comparar propriedades mecânicas de novos instrumentos de níquel-titânio com memória controlada lançados no mercado. Os sistemas WaveOne Gold (WOG; Dentsply Sirona, Ballaigues, Switzerland), WA1 File (WA1; TDKaFile, Cidade do México, México) e X1 File (X1; MK Life, Porto Alegre, RS, Brasil) foram submetidos ao teste de resistência à torção, de acordo com a norma ISO 3630-1, ao teste rigidez à flexão, através do ensaio de flexão em cantiléver (45º) e ao teste de resistência à flambagem. Os resultados foram avaliados através da análise de variância (ANOVA), o teste F e o teste de Tukey, considerando um nível de significância de 5%. No teste de resistência à torção os instrumentos WOG apresentaram maior deflexão angular, ou seja, maior resistência à fratura em torção, enquanto os instrumentos WA1 a menor e na comparação do torque máximo em torção não houve diferença estatística significante entre os sistemas. Nos testes de rigidez a flexão e resistência à flambagem houve diferença estatística significante entre os 3 sistemas, sendo os instrumentos X1 os mais rígidos. No primeiro teste os instrumentos WA1 se apresentaram como os mais flexíveis e no segundo, os instrumentos WOG. Conclui-se que os instrumentos WOG, WA1 e X1 mostraram diferenças estatísticas nos testes mecânicos, sendo os instrumentos WOG e WA1 os mais resistentes à fratura por torção e os mais flexíveis, diferentemente dos instrumentos X1 que se apresentaram mais susceptíveis à fratura por torção e menos flexíveis (AU)

Reciprocating nickel-titanium endodontic instruments have been developed to obtain a faster and safer preparation, however, these instruments have the disadvantage of fracturing during use. Facing this disadvantage, manufacturers have developed changes in instrument design and alloy finishes, as metallurgical characteristics are one of the factors that contribute to fractures. The aim of this study was to evaluate and compare mechanical properties of new nickel-titanium instruments with controlled memory. The WaveOne Gold (WOG; Dentsply Sirona, Ballaigues, Switzerland), WA1 File (WA1; TDKaFile, Mexico City, Mexico) and X1 File (X1; MK Life, Porto Alegre, RS, Brazil) systems were subjected to the torsional fatigue test, according to the ISO 3630-1 standard, flexural stiffness test, through the cantilever flexion test (45°) and buckling resistance test. The results were evaluated through analysis of variance (ANOVA), the F test and the Tukey test, considering a significance level of 5%. In the torsional fatigue test, the WOG instruments showed greater angular deflection, that is, greater resistance to torsional fracture and the WA1 instruments the lesser, and when comparing the maximum torsional torque, there was no statistically significant difference between the systems. In the flexural stiffness and buckling resistance tests, there was a statistically significant difference between the 3 systems, with the X1 instruments being the most rigid. In the first test, the WA1 instruments were the most flexible followed by the WOG instruments. In conclusion, the WOG, WA1 and X1 instruments showed differences in the mechanical tests, with the WOG and WA1 instruments being the most resistant to torsion fracture and the most flexible, unlike the X1 instruments that were more susceptible to torsion fracture and also the most rigid (AU).

Canal Cleanliness and Smear Layer Removal Using Different Irrigant Activation Methods - A Scanning Electron Microscopy Study

rrigation is one the most important aspects during root canal treatment of the teeth which can be achieved by mechanical cleaning and shaping with the aid of irrigants. However, the irrigant does not travel to all the places of the root canal especially the apical third. Hence, to make this irrigant reach the apical third, we need irrigant activation methods which will agitate the irrigant and help in accessing the places which are difficult to reach in the root canal system. The objective of this research was to check the canal cleanliness and the removal of the debris after irrigant activation using manual dynamic agitation (MDA), plastic F file, sonic irrigation (SI) and conventional syringe irrigation (CSI). METHODSSixty single rooted teeth were chosen for this study which were biomechanically prepared using ProTaper system (Dentsply Maillefer, USA) up to a preparation of F2 and 3 % NaOCl and 17 % EDTA were used as irrigants. All the samples were equally divided into groups of fifteen each depending on the mode of irrigant activation method used - Group 1, Manual Dynamic Agitation (MDA); Group 2, plastic F file; Group 3, EndoActivator (SI); and Group 4, control group (C). These teeth were then split along the long axis and were observed under the SEM for any debris and to determine the degree of canal cleanliness. RESULTSGroup 4 (control group) showed the maximum debris under SEM with a statistically significant difference with a P value less than 0.05; next was the manual dynamic agitation group. Plastic F file group and sonic irrigation groups showed almost similar results in terms of debris. CONCLUSIONSIrrigant activated using sonic mode and plastic F file efficiently removed the debris in comparison to the other two groups of syringe irrigation and manual dynamic agitation.

Disinfection and outcome of root canal treatment using single-file or multifile systems and Ca(OH)2 medication

Abstract This clinical study reports on the antibacterial effects and outcome of endodontic treatment using either a single-file or a multifile system, associated with calcium hydroxide interappointment medication. The root canals of single-rooted teeth with apical periodontitis were treated by using either Reciproc or BioRaCe instrument systems, 2.5% NaOCl irrigation, and calcium hydroxide medication. Bacteriological samples taken before preparation and immediately before obturation were evaluated for total bacterial counts by quantitative real-time polymerase chain reaction (qPCR). Patients were followed up and the treatment outcome was assessed by clinical and radiographic criteria. Decreasing lesions were classified as success in a lenient criterion or failure in a rigid one. Bacteria were detected in all initial samples (47 cases) and were significantly reduced after treatment in both groups (p<0.001). In the Reciproc and BioRaCe groups, 7/25 (28%) and 11/22 (50%) root canals yielded negative qPCR results before obturation, respectively (p>0.05). Quantitative bacterial reduction was similar between groups (p>0.05). The success rate in the BioRaCe group was 95.5% and 77% in the loose and rigid criterion, respectively. In the Reciproc group, corresponding figures were 88% and 76%. Differences in outcome were not significant (p>0.05). No diseased case showed negative qPCR results for bacteria. A difference of >1 Log10 counts was observed between healed and diseased cases. Root canal treatments of teeth with apical periodontitis using a single-file or a multifile system for preparation, associated with NaOCl irrigation and calcium hydroxide interappointment medication, showed similar antibacterial effectiveness and success rate.

Resumo Este estudo clínico relata os efeitos antibacterianos e o resultado de tratamentos endodônticos usando um sistema de instrumentação de instrumento único ou de múltiplos instrumentos, associado à medicação intracanal com hidróxido de cálcio. Os canais radiculares de 80 dentes unirradiculares com lesão perirradicular foram tratados com os sistemas Reciproc ou BioRaCe, irrigação com NaOCl a 2,5% e medicação com pasta de hidróxido de cálcio por 7 a 10 dias. Amostras bacteriológicas foram colhidas antes do preparo e imediatamente antes da obturação e examinadas quanto à contagem total de bactérias pela reação em cadeia da polimerase em tempo real quantitativa (qPCR). Os pacientes foram acompanhados e o resultado do tratamento foi avaliado por critérios clínicos e radiográficos (índice periapical). Os casos com lesões que diminuíram mas não desapareceram foram classificados como sucesso em um critério leniente ou fracasso em um critério rígido. Quarenta e sete pacientes estavam disponíveis para avaliação bacteriológica e de resultados. Bactérias foram detectadas em todas as amostras iniciais desses casos e foram significativamente reduzidas após o tratamento nos dois grupos (p<0,001). Nos grupos Reciproc e BioRaCe, os canais radiculares apresentaram resultados negativos na qPCR em 7/25 (28%) e 11/22 (50%) casos antes da obturação, respectivamente (p>0,05). A redução bacteriana foi semelhante entre os grupos (p>0,05). O período médio (mediana) de acompanhamento foi de 20,5 (18,5) meses para BioRaCe e 17,4 (18) meses para Reciproc (p>0,05). No grupo BioRaCe, a taxa de sucesso foi de 95,5% e 77% nos critérios leniente e rígido, respectivamente. No grupo Reciproc, os valores correspondentes foram 88% e 76%. As diferenças no resultado não foram estatisticamente significativas (p>0,05). Nenhum caso de doença pós-tratamento mostrou resultados negativos de qPCR para bactérias. Foi observada uma diferença >1 Log10 nas contagens bacterianas entre os casos curados e doentes. O tratamento do canal radicular de dentes com lesão perirradicular utilizando um sistema de instrumento único ou múltiplos no preparo, associado à irrigação com NaOCl e medicação entre consultas com hidróxido de cálcio, mostrou eficácia antibacteriana e taxa de sucesso semelhantes.

Arte urbano, política y memoria en 2019: Primeros pasos hacia la conformación de un archivo del muralismo político en Santiago de Chile / How to support the 2030 Agenda from the Smart Community Centers (CECIs-MICITT) stored in the National Library System (SINABI-MCJ)

Resumen El presente ensayo nace desde la inquietud en torno a la volatilidad del grafiti como obra, imagen e intervención del espacio urbano y busca ser una exploración de lo que ocurre con el grafiti muralismo en Santiago de Chile. Se centra en la vocación política de éste considerando como precedentes importantes el muralismo Mexicano como también las Brigadas Ramona Parra y Elmo Catalán. En el trabajo se hace énfasis en el muralismo con vocación política y mensajes explícitos llevándolos a lo que se ha entendido como el rol social del arte desde autores como Nelly Richard o Gaspar Galaz, aludiendo a la obra de grafiteros como Agotok, UFO o Aguarda Kiltro con importantes intervenciones en la zona sur de Santiago, sector caracterizado por el hábitat popular. A nivel metodológico se realiza una exploración en la Avenida Santa Rosa, una de las principales arterias de la zona sur de Santiago, con gran cantidad de obras en sus muros, concluyendo en el centro cultural donde se encuentra el trabajo "el gol de Chile" del destacado muralista Roberto Matta. Se hace énfasis en la necesidad de registro fotográfico del arte urbano, para llegar a formar un fondo adecuadamente ordenado para la conformación de un archivo del arte urbano que sería un campo altamente dinámico y en constante disputa, siendo un ejercicio interesante para recuperar y fortalecer la memoria histórico social. Como conclusión se destaca que el presente esbozo se plantea como un primer paso, un ejercicio reflexivo sobre la necesidad de registrar y archivar como ejercicio de memoria que puede resultar en experiencias destacables.

Abstract This essay was born from the concern about the volatility of graffiti as a work, image and intervention of urban space and seeks to be an exploration of what happens with mural graffiti in Santiago, Chile. It focuses on the political vocation of the latter considering as important precedents the Mexican muralism as well as the Ramona Parra and Elmo Catalán Brigades. The work emphasizes muralism with a political vocation and explicit messages leading them to what has been understood as the social role of art from authors such as Nelly Richard or Gaspar Galaz, referring to the work of graffiti artists such as Agotok, UFO or Aguarda Kiltro with important interventions in the southern area of ​​Santiago, a sector characterized by the popular habitat. At the methodological level, an exploration is carried out on Santa Rosa Avenue, one of the main arteries of the southern area of ​​Santiago, with a large number of works on its walls, concluding in the cultural center where the work "the goal of Chile" is located of the prominent muralist Roberto Matta. Emphasis is placed on the need for a photographic record of urban art, in order to form a properly organized fund for the conformation of an archive of urban art that would be a highly dynamic and constantly disputed field, being an interesting exercise to recover and strengthen the social historical memory. In conclusion, it is highlighted that this outline is presented as a first step, a reflective exercise on the need to register and file as a memory exercise that can result in outstanding experiences.

Accidental aspiration of endodontic file: a dreaded but a preventable complication

Accidental ingestion of dental objects has been reported previously in literature. Accidental aspiration of a dental object is however uncommon. The affected patient may exhibit varying range of symptoms depending on location, type, shape and size of the foreign body swallowed/aspirated. We report a case about successful retrieval of an aspirated endodontic file with special focus on risk factors, prevention and management of these iatrogenic complications.

Design of Multi-parameter Monitoring System Based on Embedded Linux+Qt / 中国医疗器械杂志

OBJECTIVE@#To establish the system software of multi-parameter monitoring by embedded Linux kernel and Qt library.@*METHODS@#To determine the hardware system needed for the development of the system, carry out system Bootloader (Bootloader), Linux kernel, file system and Qt/Embedded (QtE) tailoring and transplantation and application development on the basis of the hardware system, and achieve the characteristic UI design.@*RESULTS@#The changes of physiological parameters were observed in real time to improve the stability and real-time performance of the whole system and increase users' experience with QtE.@*CONCLUSIONS@#The embedded Linux+Qt multi-reference monitoring system can improve the stability, operability and functionality of real-time monitoring and multi-physiological information, and has good extensibility and maintainability.

Cleaning efficacy of two kinds of mechanical nickel-titanium instruments in preparation of severely curved root canals: A scanning electron microscopic study / 中国组织工程研究

BACKGROUND: The preparation and cleaning of severely curved root canal is the difficult point of root canal treatment. A large number of smear layer will be produced in the process of root canal preparation. Removing effectively these debris and smear layer will be conducive to improving the success rate and longterm effect of severely curved root canal treatment. OBJECTIVE: To explore the cleaning efficacy of Twisted File and ProTaper file combined with chemical preparation on smear layer of severely curved root canal by scanning electron microscope. METHODS: Twenty clinically extracted mandibular molars with severely curved root canals were collected and randomly divided into two groups: Twisted File group and ProTaper group. The root canals were prepared by Twisted file and ProTaper Ni-Ti file, respectively. They were prepared by chemical method with 3% NaClO and 17% EDTA. After preparation, the root canals were split longitudinally and the cleaning efficacy of smear layer of coronal, middle and apical thirds was observed by scanning electron microscope. RESULTS AND CONCLUSION: (1) The images of scanning electron microscope showed that the dentinal tubules of root canal coronal thirds in the ProTaper group and Twisted file group were completely open, almost without smear layer. Dentinal tubules of middle thirds were also open, and simply part of them were covered by smear layer. However, dentinal tubules of apical thirds had few and no obvious opening, and was covered by a large number of smear layer. (2) In Twisted file group, the scores of smear layer at root canal apical thirds were higher than coronal and middle thirds (P 0.05). (3) The results showed that the chemo-mechanical preparation with Twisted File and ProTaper could remove effectively the debris and smear layer in the root canal walls of coronal and middle thirds of the severely curved crown, but the removal effect on apical thirds and dentin tubules was not good.

Assessment of the Performance and Surface Alteration of Two Single-file Systems According to the Number of Uses

Abstract The aim of this study was to assess the performance and surface alteration of two single-file systems according to the number of uses. Ten WaveOne Primary files (25/.08) and ten One Shape NG files (25/.06) were used for instrumentation of mesial root canals of mandibular molars. Each instrument was cleaned and sterilized after the preparation of two root canals and then reused. The time spent for instrumentation of each root canal was recorded and analyzed by using t-test. Microphotographs of the surface of the instruments were taken with a scanning electron microscope at different magnifications (i.e. 18x, 160x, 500x and 1000x) and at a distance of 4 mm from the instrument's tip before being analyzed by four observers. Presence of disruption of cutting edge, crack, craters and unwinding was assessed and submitted to Fisher's exact test. Both systems showed manufacturing defects and cracks. The presence of disruption of cutting edges was major in WaveOne files from the sixth use, whereas One Shape NG files showed more unwinding. Only preparation time using WaveOne files was influenced by the number of uses. One can conclude that WaveOne files had more disruption of cutting edges and took longer time for root canal preparation from the sixth use onwards, whereas the One Shape NG files showed more unwinding at the tenth use.

Comparative Evaluation of Mechanical Failure of Different Rotary Endodontic Files: An SEM Study

Conventional endodontic instruments make the intracanalprocedures versatile with more efficiency and minimumcomplication. The development of microfractures in the I-RaCeNickel-Titanium rotary (NTR) file and ProFile NTR file wasevaluated by using Scanning electron microscopy (SEM).Thirty six maxillary buccal roots and thirty six mandibularmesial roots with an average canal curvature of 37° wereassigned to each group and prepared with 21mm, 0.04 taperNTR files as follows: (1) I-RaCe (2) ProFile. File sizes 0.06 to0.04 were used in a crown-down technique to a master apicalfile (MAF) size of 0.04/25. The MAF instruments wereevaluated by SEM before use, after completion of 7 canals,and after completion of 14 canals. All I-RaCe instrumentsdeveloped microfrcatures by the seven canal evaluation. TheProFile instruments showed no microfrctures at the 7-or-14canal evaluations. I-RaCe files separated at a higher rate thanProFile instruments. Under the conditions of this study, uniquefile design and electropolishing did not inhibit the developmentof microfractures in I-RaCe NTR.