Physicomechanical Properties of Tertiary Monoblock in Endodontics: A Systematic Review and Meta-analysis.

Introduction: A systematic review and meta-analysis were conducted to evaluate the physicomechanical properties of tertiary monoblock obturation with different obturation techniques. Methods and Materials: PubMed (MEDLINE), Web of Science, Scopus, the Cochrane Library, LILACS, IBECS, and BBO were searched time. PICO question was: "In extracted human teeth (Population), does tertiary monoblock obturation (Intervention) have superior physicomechanical properties (Outcome) compared to conventional obturation systems (Comparison)?". Statistical analyses for push-out bond strength were performed with RevMan software by comparing the mean differences of each study, with a 95% confidence interval. Inverse variance was used as statistical method, random-effects models as analysis model, and heterogeneity between studies was assessed by Cochran's Q test and I2 statistic (P <0.05). Results: Of 2162 studies retrieved, 31 were included in this review for "Study Characteristics". Ten studies were included in the meta-analysis. Analysis demonstrated that conventional obturation had significantly higher push-out bond strength than tertiary monoblock obturation (P <0 .01), with a mean difference of -1.00 (95% CI, -1.41 to -0.58; I2=100%). Subgroups using single-cone and cold lateral condensation techniques showed significantly lower push-out bond strength for tertiary monoblock obturation (P <0.01), respectively with a mean difference of -0.09 (95% CI, -1.13 to -0.67; I2=97%) and of -1.97 (95% CI, -3.19 to -0.75; I2=100%). The warm vertical compaction subgroup showed no statistically significant difference between tertiary monoblock and conventional systems (P =0.13), with a mean difference of 0.49 (95% CI, -0.14 to 1.12; I2=10%). Conclusion: Tertiary monoblock systems have a push-out bond strength similar to conventional systems when used with warm vertical compaction.

Knowledge level of dentists and students on HIV patient' s dental treatment in Brazil: Literature review

Background: Despite the low risk of contamination, fear and discrimination among dentists and students in relation to people infected with HIV could result in violation of some ethical precepts. Objective: The objective of this study was to review the knowledge level and attitudes of dentists and students in the dental care of patients with HIV. Methods: The last 20 years of specialized literature was consulted in the Virtual Health Libraries of Medline and Lilacs sources during the period between May 1999 and May 2019. A wide search strategy was used to avoid missing information: "Dentistry" and "HIV", registered in the Descriptors in Health Sciences. Results: The search in the database resulted in 1058 articles. Screening of titles and abstracts resulted in 14 articles. After the complete reading, 12 articles fit the inclusion and exclusion criteria. Conclusion: Based on the methodology used, it was possible to conclude that the analysis of the selected articles showed that there is still much to be done in the training and in the performance of dentists and students regarding prejudice and willingness to offer dental care for HIV patients.

Cytotoxicity of Chelating Agents Used In Endodontics and Their Influence on MMPs of Cell Membranes.

This study evaluated the cytotoxic effect and the ability to inhibit matrix metalloproteinases (MMP-2 and MMP-9) of 0.2% chitosan (CH) and 1% acetic acid (AA) compared with 17% ethylenediaminetetraacetic acid (EDTA). Cell viability assay was performed according to ISO 10993-5 with mouse fibroblasts (L929). The culture was exposed to 0.2% CH, 1% AA, and 17% EDTA. The chelating agents were evaluated immediately after contact with the cells and after 6 h, 12 h, and 24 h of incubation. Cell viability was analyzed using the 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Inhibition of the gelatinolytic activity of MMP-2 and MMP-9 was evaluated by gelatin zymography. Different concentrations of CH were evaluated: 50 mM, 5 mM, 0.5 mM, and 0.05 mM. EDTA (0.5 mM) was used as a positive control. The results demonstrated that CH and AA had an initial cytotoxic effect, which decreased after 6 h, 12 h, and 24 h, being statistically similar to EDTA (P > 0.05). Additionally, CH at concentrations of 50 mM, 5 mM, and 0.5 mM had an inhibitory effect on MMP-2 and MMP-9, similar to that of the control with EDTA. The chelating agents had no cytotoxic effects after 24 h. MMP-2 and MMP-9 were inhibited by the experimental solutions.

Cytotoxicity of chelating agents used in endodontics and their influence on mmps of cell membranes

Abstract This study evaluated the cytotoxic effect and the ability to inhibit matrix metalloproteinases (MMP-2 and MMP-9) of 0.2% chitosan (CH) and 1% acetic acid (AA) compared with 17% ethylenediaminetetraacetic acid (EDTA). Cell viability assay was performed according to ISO 10993-5 with mouse fibroblasts (L929). The culture was exposed to 0.2% CH, 1% AA, and 17% EDTA. The chelating agents were evaluated immediately after contact with the cells and after 6 h, 12 h, and 24 h of incubation. Cell viability was analyzed using the 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Inhibition of the gelatinolytic activity of MMP-2 and MMP-9 was evaluated by gelatin zymography. Different concentrations of CH were evaluated: 50 mM, 5 mM, 0.5 mM, and 0.05 mM. EDTA (0.5 mM) was used as a positive control. The results demonstrated that CH and AA had an initial cytotoxic effect, which decreased after 6 h, 12 h, and 24 h, being statistically similar to EDTA (P > 0.05). Additionally, CH at concentrations of 50 mM, 5 mM, and 0.5 mM had an inhibitory effect on MMP-2 and MMP-9, similar to that of the control with EDTA. The chelating agents had no cytotoxic effects after 24 h. MMP-2 and MMP-9 were inhibited by the experimental solutions.

Resumo Este estudo avaliou o efeito citotóxico e a capacidade de inibição das metaloproteinases da matriz extracelular (MMP-2 e MMP-9) pela quitosana 0,2%(CH) e o ácido acético 1% (AA) em comparação com o ácido etilenodiaminotetracético 17% (EDTA). O ensaio de viabilidade celular foi realizado de acordo com a ISO 10993-5 com fibroblastos de camundongo (L929). A cultura foi exposta a CH 0,2%, AA 1% e EDTA 17%. Os agentes quelantes foram avaliados imediatamente após o contato com as células e após 6 h, 12 h e 24 h de incubação. A viabilidade celular foi analisada utilizando o ensaio de brometo de 3- (4,5-dimetitiazol-2-il) -2,5-difeniltetrazólio (MTT). A inibição da atividade gelatinolítica de MMP-2 e MMP-9 foi avaliada por zimografia de gelatina. Diferentes concentrações de CH foram avaliadas: 50 mM, 5 mM, 0,5 mM e 0,05 mM. EDTA (0,5 mM) foi usado como controlo positivo. Os resultados demonstraram que CH e AA apresentaram um efeito citotóxico inicial, que diminuiu após 6 h, 12 h e 24 h, sendo estatisticamente similar ao EDTA (P> 0,05). Adicionalmente, CH a concentrações de 50 mM, 5 mM e 0,5 mM tiveram um efeito inibidor sobre MMP-2 e MMP-9, semelhante ao controlo com EDTA. Os agentes quelantes apresentaram efeitos não citotóxicos após 24 h. MMP-2 e MMP-9 foram inibidas pelas soluções experimentais.

Taxas de prevalência de hanseníase nas macrorregiões do estado de Mato Grosso: Datasus-Brasil / Leprosy prevalence rates in Mato Grosso state macroregions: Datasus-Brazil / Tasas de prevalencia de lepra en macrorregiones del estado de Mato Grosso: Datasus-Brazil

Objetivo: analisar e comparar taxas de prevalência de hanseníase nas macrorregiões do estado de Mato Grosso a partir informações coletadas do Departamento de Informática do Sistema Único de Saúde (DATASUS) do Ministério da Saúde do Brasil. Método: estudo retrospectivo transversal onde analisou a taxa de prevalência no período de janeiro a dezembro de 2017. Os dados foram obtidos através do (DATASUS). Os valores foram comparados por análise de variância, testes de KolmogorovSmirnov e Levene, seguidos pelo teste post hoc de Tukey, com nível de significância em p<0,05. Resultados: Houve diferença estatisticamente significante entre as Macrorregiões do estado de Mato Grosso, Teles Pires, Vale do Peixoto, Vale do Arinos e Médio Araguaia, consideradas "hiperendêmicas". Conclusão: As taxas de prevalência de hanseníase encontradas neste estudo a partir da utilização da ferramenta DATASUS avaliando as macrorregiões do estado de Mato Grosso abrem perspectivas futuras para estudo epidemiológicos bem elaborados bem como a análise da qualidade dos serviços de saúde utilizados. A ferramenta DATASUS pode ser utilizada no planejamento de políticas públicas para a hanseníase.(AU)

Background: Objective: To analyze and compare leprosy prevalence rates in the macroregions of the state of Mato Grosso from information collected from the Department of Informatics of the Unified Health System (DATASUS) of the Brazilian Ministry of Health. Method: a retrospective cross-sectional study analyzing the prevalence rate from January to December 2017. Data were obtained through (DATASUS). The values were compared by analysis of variance, Kolmogorov-Smirnov and Levene tests, followed by Tukey post hoc test, with significance level of p <0.05. Results: There was a statistically significant difference between the macroregions of the state of Mato Grosso, TelesPires, Peixoto Valley, Arinos Valley and Middle Araguaia, considered "hyperendemic". Conclusion: The prevalence rates of leprosy found in this study from the use of the DATASUS tool evaluating the macro-regions of the state of Mato Grosso open future perspectives for well-prepared epidemiological studies as well as the analysis of the quality of the health services used. DATASUS tool can be used in the planning of public policies for leprosy.(AU)

Objetivo: analizar y comparar las tasas de prevalencia de lepra en los macrorregiones del estado de Mato Grosso a partir de la información recopilada del Departamento de Informática del Sistema Único de Salud (DATASUS) del Ministerio de Salud de Brasil. Método: estudio retrospectivo transversal que analiza la tasa de prevalencia de enero a diciembre de 2017. Los datos se obtuvieron a través de (DATASUS). Los valores se compararon mediante análisis de varianza, pruebas de KolmogorovSmirnov y Levene, seguidas de la prueba post hoc de Tukey, con un nivel de significación de p <0,05. Resultados: Hubo una diferencia estadísticamente significativa entre los macrorregiones del estado de Mato Grosso, Teles Pires, Peixoto Valley, Arinos Valley y medio Araguaia, consideradas "hiperendémicas". Conclusión: Las tasas de prevalencia de lepra encontradas en este estudio a partir del uso de la herramienta DATASUS que evalúa las macro regiones del estado de Mato Grosso abren perspectivas futuras para estudios epidemiológicos bien preparados, así como el análisis de la calidad de los servicios de salud utilizados. La herramienta DATASUS se puede utilizar en la planificación de políticas públicas.(AU)

Experimental Resin-Based Monoblock Endodontic Obturation System.

OBJECTIVE: The aim of the present study was to characterize a novel resin-based monoblock endodontic obturation system consisting of a polymeric cone and a resin-based endodontic sealer. METHODS: The preliminary tests performed for the experimental cone were as follows: cohesive strength, dimensional stability, standardization of the diameter and taper, calcium ion release, and radiopacity, for the characterization of the experimental sealer, film thickness and flow tests were performed. Tests were performed according to the American National Standards Institute/American Dental Association (ANSI/ADA) Standards Nos. 57 and 78. The experimental cone was compared to gutta-percha, whereas the experimental sealer was compared to AH Plus. Data were analyzed by Student's t-test (α = 0.05). RESULTS: The experimental cone had superior values for cohesive strength and dimensional stability compared to gutta-percha. Regarding calcium ion release, the experimental system continued to release calcium ions after 30 days. Film thickness was similar for both endodontic sealers; conversely, the experimental resin-based sealer achieved higher values for flow compared to AH Plus. CONCLUSION: The experimental resin-based monoblock obturation system fully met the requirements of the ANSI/ADA Standard No. 78 and the ANSI/ADA Standard No. 57, except for radiopacity. Considering this, further studies are still needed to evaluate other radiopacifiers and the effect of their incorporation on the physicochemical properties of this novel resin-based monoblock endodontic obturation system.

Nonsurgical management of endodontic iatrogeny using mta plug: A case report

Endodontic treatment confronting previous iatrogeny in teeth with incomplete root formation and apical periodontitis is presented as a challenge to the Endodontists. The sanitization and peri-radicular repair can be achieved by the assist of auxiliary materials to biomechanical treatment procedures. MTA is cogitated as a choice for these cases due to its composition, physicochemical, mechanical and biological properties. In this case report, the patient presented tooth 11 with incomplete root formation and peri-radicular radiolucent lesion accompanied by the presence of an inverted gutta-percha cone in an attempt to filling the root canal. Endodontic treatment was accomplished by removal of the previous gutta-percha. After determining the working length, biomechanical preparation was achieved up until #80 K-file. Sequentially application of calcium hydroxide, as intracanal medication, was performed. Six monthly exchanges of intracanal dressing were completed. Apex was sealed with MTA bonded with saline through #4 Paiva condenser, creating an apical plug. The tooth was temporarily sealed, and patient returned after a week to perform the root canal filling with gutta-percha associated to Sealapex. The final radiography shows apical tissue repair with no peri-radicular lesions and clinical signs of successful treatment. This case report highlights the tissue repair and lack of local infection, absence of sensitivity pain or edema. These findings indicated that these approaches could be elect to presence of necrotic lesions achieving tissue repair.

Evaluation of Selective Physicochemical and Biological Properties of Different Root Canal Sealers.

Introduction: This in vitro study aimed to evaluate the chemical composition, water solubility, radiopacity, pH, electrical conductivity and cytotoxicity of four different root canal sealers. Methods and Materials: Four materials were tested including an epoxy resin-based sealer (AH-Plus), a calcium silicate-based sealer (MTA Fillapex), a calcium hydroxide-based sealer (Sealapex) and a zinc-oxide-eugenol-based sealer (Endofill). The materials were submitted to energy-dispersive x-ray microanalysis for elemental chemical composition. Solubility and radiopacity were evaluated according to ANSI/ADA. The pH and electrical conductivity were measured at different periods of time. L929 immortalized mouse fibroblast line were used for cytotoxicity evaluation. Statistical analyses were carried out using the ANOVA and Tukey's test. Results: The main elements were found to be silicon and calcium in MTA Fillapex, calcium and bismuth in Sealapex, zirconium and tungsten in AH-Plus and zinc and bismuth in Endofill. Sealapex had the highest value for solubility (P<0.05), AH-Plus showed the highest radiopacity value (P<0.05) while MTA Fillapex had the highest pH and electrical conductivity values (P<0.05). AH-Plus showed the highest rate of cell viability (P<0.05). Conclusion: Based on the results of this in vitro study, it was possible to conclude that Endofill and Sealpex did not meet the requirements for water solubility. The tested sealers were alkaline and showed radiopacity in accordance with ANSI/ADA standards. AH-Plus showed to be less cytotoxic than other tested root canal sealers.

Effectiveness of different endodontic irrigants against Enterococcus faecalis: an ex vivo study

Aim: To evaluate the effectiveness of different endodontic irrigants against Enterococcus faecalis (ATCC 29212). Methods: Seventy bovine mandibular incisors were prepared, inoculated with a bacterial strain for 60 days and divided into the following groups: positive control; negative control; 2.5% NaOCl; 17% EDTA; 0.2% chitosan; 2.5% NaOCl + 0.2% chitosan; and 2.5% NaOCl + 17% EDTA. The irrigation protocol was performed using an experimental peristaltic pump device, with the irrigating solutions circulating within the apparatus at a constant flow for 10 min. Paper-point samples were then collected from the root canals and immersed in 7 mL of brain heart infusion broth, followed by incubation at 37°C for 48 h. Bacterial growth was assessed by turbidity of the culture medium. Results: E. faecalis was present in all samples after the use of different irrigants. Conclusion: The different irrigants tested were not effective in completely eliminating dentin bacterial contamination with E. faecalis.

Sextuple Tumors in Head and Neck Area: Evidence of Field Cancerization.

BACKGROUND: Field cancerization is a phenomenon in which prolonged exposure to carcinogens induces changes throughout the epithelium leaving the field ready for the appearance of premalignant or malignant lesions. These alterations can promote the development of multiple carcinomas and explain the appearance of recurrences and second primary tumors. The objective of this study was to report the case of a patient who developed six oral cavity tumors in five years of treatment and, also, demonstrate the immunohistochemical changes for p53 and Ki-67, routinely used to assess dysplasic regions. CASE REPORT: When altered, p53 and Ki-67 suggest the presence of field cancers, an area with genetically altered cells, presenting a high risk of developing premalignant and malignant lesions. This phenomenon explains the recurrence of malignant neoplasms after tumor resections. CONCLUSION: In addition, early identification of potentially malignant lesions in cases of second primary tumors is essential for effective treatment and patient survival, which usually have an unwelcoming prognosis.

Produção endodôntica no atendimento público odontológico do Centro-Oeste do Brasil / Provision of endodontics in specialized public centers for dental care in the Center-West of Brazil

Pouco se sabe sobre o atendimento público odontológico no Centro-Oeste do Brasil, ainda menos sobre sua produção endodôntica. Esta produção é realizada principalmente nos Centros de Especialidades Odontológicas (CEO), referência pública para tratamento endodôntico, acessível na base de dados DATASUS. Foi objetivo deste estudo explorar a produção endodôntica nas capitais dos estados da Região Centro-Oeste e do Distrito Federal do Brasil. Este estudo retrospectivo transversal analisou a produção endodôntica destes municípios de janeiro de 2011 a dezembro de 2016. Os dados foram obtidos consultando as bases do Ministério da Saúde (DATASUS) e do Instituto Brasileiro de Geografia e Estatística (IBGE). Os valores foram comparados por análise de variância e os testes de Kolmogorov-Smirnov e Levene seguidos pelo teste post hoc de Tukey. O nível de significância foi definido em p<0,05. Dentre as cidades analisadas, Campo Grande teve a maior produção endodôntica por habitante, seguida de Cuiabá e Goiânia com produções similares, e Brasília. Os dentes com três ou mais canais radiculares apresentaram maior incidência de tratamento endodôntico comparados a dentes com um ou dois canais radiculares. A produção endodôntica dos CEO das capitais dos estados da Região Centro-Oeste e do Distrito Federal do Brasil foi proporcionalmente maior em Campo Grande e menor em Brasília. O tratamento endodôntico foi realizado preferencialmente nos dentes com três ou mais canais radiculares. As instituições de ensino devem estar atentas às mudanças para que seus egressos sejam formados em consonância com o perfil epidemiológico da população bem como com as políticas públicas de saúde (AU).

Pouco se sabe sobre o atendimento público odontológico no Centro-Oeste do Brasil, ainda menos sobre sua produção endodôntica. Esta produção é realizada principalmente nos Centros de Especialidades Odontológicas (CEO), referência pública para tratamento endodôntico, acessível na base de dados DATASUS. Foi objetivo deste estudo explorar a produção endodôntica nas capitais dos estados da Região Centro-Oeste e do Distrito Federal do Brasil. Este estudo retrospectivo transversal analisou a produção endodôntica destes municípios de janeiro de 2011 a dezembro de 2016. Os dados foram obtidos consultando as bases do Ministério da Saúde (DATASUS) e do Instituto Brasileiro de Geografia e Estatística (IBGE). Os valores foram comparados por análise de variância e os testes de Kolmogorov-Smirnov e Levene seguidos pelo teste post hoc de Tukey. O nível de significância foi definido em p<0,05. Dentre as cidades analisadas, Campo Grande teve a maior produção endodôntica por habitante, seguida de Cuiabá e Goiânia com produções similares, e Brasília. Os dentes com três ou mais canais radiculares apresentaram maior incidência de tratamento endodôntico comparados a dentes com um ou dois canais radiculares. A produção endodôntica dos CEO das capitais dos estados da Região Centro-Oeste e do Distrito Federal do Brasil foi proporcionalmente maior em Campo Grande e menor em Brasília. O tratamento endodôntico foi realizado preferencialmente nos dentes com três ou mais canais radiculares. As instituições de ensino devem estar atentas às mudanças para que seus egressos sejam formados em consonância com o perfil epidemiológico da população bem como com as políticas públicas de saúde (AU).

Physical and Biological Properties of a High-Plasticity Tricalcium Silicate Cement.

INTRODUCTION: Mineral Trioxide Aggregate (MTA) is a tricalcium-based silicate, dicalcium silicate matrix. Despite its good biologic properties, some clinicians still claim to have difficulties in handling MTA after its preparation due to its sandy consistency. The aim of the present study was to evaluate the physicochemical properties and cytotoxicity of MTA Repair HP (Angelus, Londrina, PR, Brazil) compared with MTA Angelus (Angelus, Londrina, PR, Brazil). MATERIALS AND METHOD: The properties assessed were particle size, setting time, flow, film thickness, radiopacity, water solubility, compressive strength, and cytotoxicity. Statistical analysis was performed considering p < 0.05 as statistically significant. RESULTS: For radiopacity, water absorption and solubility MTA Repair HP were statistically similar to MTA Angelus. The MTA Angelus had statistically different film thickness values, higher than MTA Repair HP (p < 0.05). Besides, MTA Angelus showed a lower and statistically different compressive strength after 28 days than MTA Repair HP (p<0.05). Additionally, MTA Repair HP set more slowly (p < 0.05). Relative to cell viability, MTA Repair HP was statistically similar to MTA Angelus after 24 and 48 h in cell viability. CONCLUSIONS: The MTA Repair HP presented similar cell viability, lower film thickness, higher flow, setting time, and compressive strength values after 28 days than MTA Angelus. In general, the MTA Repair HP presented physicochemical and biological properties similar to the MTA Angelus.

Influence of Cervical Preflaring on the Incidence of Root Dentin Defects.

INTRODUCTION: This study evaluated the influence of cervical preflaring on the incidence of root dentin defects after root canal preparation. METHODS: Extracted human maxillary central incisors were selected and allocated to 1 control group and 12 experimental groups (n = 15). Teeth in the control group were left unprepared, whereas the others were prepared using 2 reciprocating single-file systems (Reciproc and WaveOne [WO]), 3 full-sequence rotary systems (ProTaper Universal, ProTaper Next [PTN], and ProFile), and K-files driven by an oscillatory system, with and without cervical preflaring. Roots were then horizontally sectioned at 4, 8, and 12 mm from the apex, stained with 1% methylene blue, and viewed through a stereomicroscope at ×25 magnification. Slices were inspected and the absence/presence of defects (fractures, partial cracks, and craze lines) recorded. Data were analyzed using Kolmogorov-Smirnov and Levene tests followed by the Tukey post hoc test at a significance level of P < .05. RESULTS: No root dentin defects were observed in the control group. WO was associated with a significantly higher number of defects than K-files, ProFile, and PTN (P < .05), but was not significantly different from Reciproc or ProTaper Universal (P > .05). Cervical preflaring significantly reduced the incidence of fractures and other defects in the WO and PTN groups (P < .05). CONCLUSIONS: All instruments caused root dentin defects, regardless of the enlargement or not of the cervical portion. Cervical preflaring was associated with a lower incidence of defects, mainly in root canals prepared with WO and PTN.

Forensic DNA typing from teeth using demineralized root tips.

Teeth are widely used samples in forensic human genetic identification due to their persistence and practical sampling and processing. Their processing, however, has changed very little in the last 20 years, usually including powdering or pulverization of the tooth. The objective of this study was to present demineralized root tips as DNA sources while, at the same time, not involving powdering the samples or expensive equipment for teeth processing. One to five teeth from each of 20 unidentified human bodies recovered from midwest Brazil were analyzed. Whole teeth were demineralized in EDTA solution with daily solution change. After a maximum of approximately seven days, the final millimeters of the root tip was excised. This portion of the sample was used for DNA extraction through a conventional organic protocol. DNA quantification and STR amplification were performed using commercial kits followed by capillary electrophoresis on 3130 or 3500 genetic analyzers. For 60% of the unidentified bodies (12 of 20), a full genetic profile was obtained from the extraction of the first root tip. By the end of the analyses, full genetic profiles were obtained for 85% of the individuals studied, of which 80% were positively identified. This alternative low-tech approach for postmortem teeth processing is capable of extracting DNA in sufficient quantity and quality for forensic casework, showing that root tips are viable nuclear DNA sources even after demineralization.

Assessment of the Amount of Calcium Ions Released after the use of Different Chelating Agents and Agitation Protocols.

BACKGROUND: The main goal of endodontic treatment is to achieve cleaning and shaping prior to the filling process. OBJECTIVE: This study aimed to evaluate, using atomic absorption spectrometry, the release of Calcium ions after the use of different chelating agents and protocols of agitation. METHOD: Ninety human canine teeth were randomly assigned to one of nine groups (n=10), as follows: 1) 0.2% Chitosan and manual agitation; 2) 0.2% Chitosan and sonic agitation; 3) 0.2% Chitosan and ultrasonic agitation; 4) 17% EDTA and manual agitation; 5) 17% EDTA and sonic agitation; 6) 17% EDTA and ultrasonic agitation; 7) distilled water and manual agitation; 8) distilled water and sonic agitation; 9) distilled water and ultrasonic agitation. Following instrumentation, all chelating substances remained inside the root canal for 3 min. Then the fluid was collected for the identification and quantification of Calcium ions. The amount of Calcium ions released in each group was compared using analysis of variance (ANOVA) and the Kolmogorov-Smirnov and Levene tests followed by Tukey's post-hoc test. Significance was set at 5%. RESULTS: The groups in which 0.2% Chitosan was used showed the highest concentration of Calcium ions (p<0.05). Concerning the agitation method, ultrasonic agitation showed the greatest values, followed by sonic and manual agitation (all comparisons, p<0.05). CONCLUSION: The present findings suggest that, among the combinations here tested, Chitosan associated with ultrasonic agitation yielded the greatest release of Calcium ions.

The Influence of Cervical Preflaring on the Amount of Apically Extruded Debris after Root Canal Preparation Using Different Instrumentation Systems.

INTRODUCTION: The objective of this study was to evaluate the influence of cervical preflaring on the amount of apically extruded debris after root canal preparation using different instrumentation systems. METHODS: One hundred eighty human maxillary central incisors were selected and randomly divided into 12 groups (n = 15). Root canals were instrumented according to manufacturers' instructions using 2 reciprocating single-file systems (Reciproc [VDW, Munich, Germany] and WaveOne [Dentsply Maillefer, Ballaigues, Switzerland]), 3 full-sequence rotary systems (ProTaper Universal [Dentsply Maillefer], ProTaper Next [Dentsply Tulsa Dental, Tulsa, OK], and ProFile [Dentsply Maillefer]), and K-files (Dentsply Maillefer) driven by an oscillatory system with and without cervical preflaring. Bidistilled water was used as irrigant. Apically extruded debris was collected in preweighed glass vials using the Myers and Montgomery method. After drying, the mean weight of debris was determined using a microbalance. Kolmogorov-Smirnov and Levene tests followed by the Tukey post hoc test were used for statistical analysis. RESULTS: K-files produced significantly more debris than all of the other systems (P < .05). For all systems, cervical preflaring reduced the amount of apically extruded debris when compared with no cervical preflaring (P < .05). CONCLUSIONS: All of the systems extruded debris, irrespective of the preparation technique used (with or without cervical preflaring). Cervical preflaring was associated with the extrusion of smaller quantities of apical debris.