How is working length determination taught? A survey to assess what is recommended in undergraduate Schools of Dentistry in Brazil.

INTRODUCTION: To analyse what are the methods for working length (WLD) determination taught for undergraduate students in Brazilian Dental Schools and the perception of professors about the use of electronic WL determination in the clinical practice. METHODS: An online questionnaire with eighteen closed questions was sent to 209 Schools of Dentistry in Brazil using the Google Forms Platform. The questionnaire was structured to analyse the perception of professors in the department of endodontics about the method of working length determination taught in undergraduate courses in Dentistry. The data collected in the questionnaires were transferred to an Excel® spreadsheet and analysed using absolute and relative frequencies. The non-parametric Mann-Whitney test was used to compare groups. RESULTS: Of the 209 schools contacted, 41 (19.61%) returned answers to the questionnaire. According to professors, electronic working length (WL) determination had a shorter length of time to perform it (p < .001), WL measurement accuracy (p < .001) and ease of performance (p < .001). Professors felt safer when maintaining patency when using electronic WL determination (p = .0020). CONCLUSIONS: Both radiographic and electronic methods of WL determination are taught in Brazilian Schools of Dentistry. The electronic method was used more frequently, especially in undergraduate clinical courses.

Análise da prática endodôntica realizada em clínicas odontológicas em uma cidade do Sul do Brasil / Analysis of endodontic practices in dental clinics in a Southern Brazilian city

Introdução: O desenvolvimento de novas técnicas, tecnologias e materiais influenciam a prática clínica da endodontia e impactam consideravelmente a forma como o tratamento do canal radicular é realizado. Embora existam informações sobre as várias formas de tratamentos praticados por dentistas em outras cidades e/ou países, muito pouco se sabe sobre as endodontias realizadas em clínicas odontológicas na cidade de Porto Alegre/RS. Objetivo: Analisar a prática endodôntica realizada por dentistas nas clínicas odontológicas na cidade de Porto Alegre/RS, visando explorar as técnicas, materiais e equipamentos empregados durante o tratamento. Material e método: Foi aplicado um questionário online, por meio da Plataforma Google Forms, com vinte e seis questões abertas e fechadas aos dentistas que realizam tratamentos endodônticos em clínicas odontológicas. O questionário foi estruturado a fim de analisar os materiais, técnicas e equipamentos que estão presentes nos tratamentos endodônticos realizados pelos dentistas nas clínicas odontológicas aqui avaliadas. Os dados coletados nos questionários foram transferidos para uma planilha Excel®. A análise dos dados foi feita de duas formas: frequência absoluta e relativa para as questões fechadas, e descritiva para as questões abertas. Resultado: 15,57% das clínicas odontológicas registradas no CRO/RS participaram da presente pesquisa. Foi possível verificar que a maioria dos materiais e técnicas aplicadas no tratamento endodôntico são os mesmos recomendados pela literatura científica. Conclusão: Os protocolos clínicos em endodontia seguidos pelos participantes do presente estudo apresentam embasamento clínico e científico na literatura.

Introduction: The evolution of new techniques, technologies, and materials significantly influences the clinical practice of endodontics, thus profoundly impacting the approach to root canal treatments. While information about various treatment methods practiced by dentists in other cities or countries is available, there is a notable gap in our understanding of endodontic practices in the Porto Alegre city. Objective: The objective of this study is to analyze the endodontic practices employed by dentists in dental clinics located in Porto Alegre city. We aimed to explore the techniques, materials, and equipment routinely utilized during endodontic treatments. Material and method: An online questionnaire using the Google Forms platform was administered, consisting of twenty-six open and closed questions to dentists performing endodontic treatments in dental clinics. The questionnaire was structured to assess the materials, techniques, and equipment employed during endodontic procedures. Data collected from the questionnaires were recorded in an Excel® spreadsheet. Data analysis encompassed both absolute and relative frequency for closed questions and also a descriptive approach for open-ended questions. Results: Participation was obtained from 15.57% of dental clinics registered with CRO/RS. The findings indicated that the majority of materials and techniques applied in endodontic treatment could be aligned with recommendations found in the scientific literature. Conclusion: The clinical protocols observed by the participants in endodontic practice demonstrated a solid foundation in both clinical and scientific literature.

Morphometric evaluation of multirooted artificial teeth used for endodontic training / Avaliação morfométrica de dentes artificiais polirradiculares utilizados para treinamento endodôntico

Introduction Dental practice professionals encounter several urgency cases, mainly related to endodontic problems. To attend to these, professionals need extensive prior preclinical training, being one of the main difficulties the search for models that simulate dental morphology. Aim To compare the external morphometry of multirooted artificial teeth to literature. Material and method The artificial teeth (Upper First Premolar, Upper First Molar and Lower First Molar) were donated by the manufacturers: Fábrica de Sorrisos (FS) and IM do Brasil LTDA (IM), totaling 30 teeth. The total length of the tooth and root, height and buccal-palatal and mesial-distal dimensions of the crown were measured with a digital pachymeter. The data were placed in a spreadsheet and the statistical analysis was performed [ANOVA or Kruskal-Wallis and then, Dunnett's test (α=5%)]. Result The Upper Molar samples of the company Fábrica de Sorrisos presented all variables within the morphometric patterns described in the literature. The other dental groups presented statistically significant differences, maintaining or not a certain proportionality. Conclusion Of all the dental groups analyzed, the upper molar from the company Fábrica de Sorrisos was the only one that presented all the external morphometric aspects according to literature.

Introdução Dentro da prática odontológica, os profissionais podem receber diversos casos de urgência, principalmente relacionados a problemas endodônticos e, para atendê-los, há a necessidade de um extenso treinamento pré-clínico prévio, sendo uma das principais dificuldades a busca por modelos que simulem a morfologia dentária. Objetivo Comparar a morfometria de dentes artificiais polirradiculares à literatura. Material e método Os dentes artificiais (Primeiro Pré-molar Superior, Primeiro Molar Superior e Primeiro Molar Inferior) foram doados pelos fabricantes: Fábrica de Sorrisos (FS) e IM do Brasil Ltda. (IM), totalizando 30 dentes. Foi realizada mensuração do comprimento total do dente e o da raiz, da altura e das dimensões vestíbulo-palatina e mésio-distal da coroa, com paquímetro digital. Os dados foram dispostos em uma planilha de cálculo e realizou-se a análise estatística [ANOVA ou Kruskal-Wallis e, após, teste de Dunnett (α=5%)]. Resultado A amostra de molares superiores da empresa FS apresentou todas as variáveis dentro dos padrões morfométricos descritos na literatura. Os demais grupos dentários apresentaram diferenças estatisticamente significantes, mantendo ou não certa proporcionalidade. Conclusão De todos os grupos dentários pesquisados o molar superior da empresa FS foi o único que apresentou todos os aspectos morfométricos externos de acordo com os dados da literatura.

LPS levels in root canals after the use of ozone gas and high frequency electrical pulses.

The present study aims to verify the effect of ozone gas (OZY® System) and high frequency electric pulse (Endox® System) systems on human root canals previously contaminated with Escherichia colilipopolysaccharide (LPS). Fifty single-rooted teeth had their dental crowns removed and root lengths standardized to 16 mm. The root canals were prepared up to #60 hand K-files and sterilized using gamma radiation with cobalt 60. The specimens were divided into the following five groups (n = 10) based on the disinfection protocol used: OZY® System, one 120-second-pulse (OZY 1p); OZY® System, four 24-second-pulses (OZY 4p); and Endox® System (ENDOX). Contaminated and non-contaminated canals were exposed only to apyrogenic water and used as positive (C+) and negative (C-) controls, respectively. LPS (O55:B55) was administered in all root canals except those belonging to group C-. After performing disinfection, LPS samples were collected from the canals using apyrogenic paper tips. Limulus Amoebocyte Lysate (LAL) was used to quantify the LPS levels, and the data obtained was analyzed using one-way ANOVA. The disinfection protocols used were unable to reduce the LPS levels significantly (p = 0.019). The use of ozone gas and high frequency electric pulses was not effective in eliminating LPS from the root canals.

Avaliação de dentes monorradiculares artificiais utilizados para treinamento endodôntico / Evaluation of artificial monoradicular teeth used for endodontic training

Introdução: É desafio do ensino pré-clínico em Endodontia fornecer aos alunos dentes artificiais que reproduzam a morfologia dos dentes humanos. Objetivo: Comparar a morfologia interna e externa de dentes artificiais monorradiculares com dados da literatura sobre dentes humanos. Material e método: Os dentes artificiais foram doados pelos fabricantes: Fábrica de Sorrisos, empresa A, (n=20), e IM do Brasil Ltda., empresa B, (n=20). Foi realizada mensuração do comprimento total do dente e da raiz, da altura, das dimensões vestibulopalatina e mesiodistal da coroa, com paquímetro digital. A descrição morfológica das raízes, coroas e câmaras pulpares foi realizada. A localização topográfica do forame apical principal foi avaliada após exploração dos canais com instrumento endodôntico tipo K #15 até este atingir visualmente o ápice radicular. Os dados foram dispostos em uma planilha de cálculo e realizou-se a análise estatística [ANOVA e pós-teste de Tukey (α=5%)]. Resultado: A amostra de caninos superiores da empresa B apresentou todas as variáveis dentro dos padrões morfométricos descritos na literatura. Em relação às morfologias interna e externa, a amostra de incisivos laterais superiores da empresa A foi a única a apresentar todas as variáveis dentro dos padrões descritos na literatura. Em relação à localização topográfica foraminal, os dentes da empresa A, assim como o canino inferior da empresa B, apresentaram tendência à posição distalizada e centralizada, vindo ao encontro da literatura. Conclusão: Nenhum dente artificial estudado apresentou total similaridade morfológica e morfométrica com a literatura analisada, diferindo em pelo menos uma das variáveis, sendo indicada aos fabricantes uma revisão dos seus modelos.

Introduction: It is a challenge of pre-clinical teaching in Endodontics to provide students with artificial teeth that reproduce the internal and external morphology of human teeth. Objective: To compare the internal and external morphology of single-rooted artificial teeth with data from the literature on human teeth. Material and method: The artificial teeth were donated from two companies: Fábrica de Sorrisos, company A, (n=20) and IM do Brasil Ltda, company B (n=20). Measurement of total tooth length, root, height, buccal-palatal and mesio-distal crown dimensions with digital caliper was performed. The morphological description of the roots, crown and pulp chamber was performed, the last one only after access. The topographic location of the main apical foramen was evaluated after canal exploration with a K #15 endodontic instrument until it visually reached the root apex. The data were arranged in a spreadsheet and statistical analysis was performed (ANOVA, followed by the Tukey post-test (α=5%)). Result: Regarding the morphometric parameters, the upper canine sample from company B presented all variables within the standards described in the literature. Regarding internal and external morphology, the sample of upper lateral incisors from Company A was the only one to present all variables within the standards described in the literature. Regarding the foraminal topographic location, the teeth of Company A, as well as the lower canine of company B, showed a tendency to the distalized and centralized position, in line with the literature. Conclusion: none of the artificial teeth studied showed total morphological and morphometric similarity with the control, differing in at least one of the variables, and a review of their models is indicated to the manufacturers.

QMix® irrigant reduces lipopolysacharide (LPS) levels in an in vitro model.

The presence of endotoxin inside the root canal has been associated with periapical inflammation, bone resorption and symptomatic conditions.Objectives To determine, in vitro, the effect of QMix® and other three root canal irrigants in reducing the endotoxin content in root canals.Material and Methods Root canals of single-rooted teeth were prepared. Samples were detoxified with Co-60 irradiation and inoculated with E. coli LPS (24 h, at 37°C). After that period, samples were divided into 4 groups, according to the irrigation solution tested: QMix®, 17% EDTA, 2% chlorhexidine solution (CHX), and 3% sodium hypochlorite (NaOCl). LPS quantification was determined by Limulus Amebocyte Lysate (LAL) assay. The initial counting of endotoxins for all samples, and the determination of LPS levels in non-contaminated teeth and in contaminated teeth exposed only to non-pyrogenic water, were used as controls.Results QMix® reduced LPS levels, with a median value of 1.11 endotoxins units (EU)/mL (p<0.001). NaOCl (25.50 EU/mL), chlorhexidine (44.10 EU/mL) and positive control group (26.80 EU/mL) samples had similar results. Higher levels were found with EDTA (176.00 EU/mL) when compared to positive control (p<0.001). There was no significant difference among EDTA, NaOCl and CHX groups. Negative control group (0.005 EU/mL) had statistically significant lower levels of endotoxins when compared to all test groups (p<0.001).Conclusion QMix® decreased LPS levels when compared to the other groups (p<0.001). 3% NaOCl, 2% CHX and 17% EDTA were not able to significantly reduce the root canal endotoxins load.

Are bovine teeth a suitable substitute for human teeth in in vitro studies to assess endotoxin load in root canals?

The present study aimed to determine the feasibility of using bovine teeth as a suitable alternative for human teeth, in experiments involving in vitro endotoxin contamination. Twenty bovine central incisors and 20 human single-root premolars had their dental crowns removed and root lengths set at 16 mm. Root canals were prepared up to #60 K-file size and sterilized with cobalt-60 gamma irradiation (20 kGy, 6 h). The teeth were randomly divided into four groups: G1-bovine teeth (bovine negative control, n = 10), G2-human teeth (human negative control, n = 10), G3-bovine teeth, inoculated with Escherichia coli (055:B55) LPS, and G4-human teeth inoculated with E. coli LPS. The G1 and G2 groups were exposed to apyrogenic water. After the teeth had been incubated at 37 °C and atmospheric humidity for 24 h, the samples of solutions in the main canals were collected with apyrogenic absorbent paper tips. LPS levels were quantified using Limulus Amebocyte Lysate assay. The data obtained were statistically analyzed using one-way ANOVA, with a significance level of 5%. A high amount of endotoxin was detected in the inoculated human teeth (G4) when compared to the sterilized teeth (G2), as well as in the inoculated bovine teeth (G3) when compared to the inoculated human teeth (G4). However, there was no statistical difference between bovine teeth before and after the E. coli endotoxin inoculation. Therefore, under the mentioned experimental conditions, the use of bovine teeth should not be a choice for laboratory research on endotoxin contamination.

Efeito de diferentes soluções irrigadoras na microdureza superficial Knoop de dentes artificiais / Effect of different irrigation solutions on the Knoop surface microhardness of artificial teeth

Resumo Introdução Dentes artificiais têm sido empregados para a prática de ensino pré-clínico. Porém, não se sabe o comportamento dos mesmos frente aos diferentes procedimentos realizados durante um tratamento endodôntico simulado. Objetivo Avaliar a microdureza de réplicas de dentes humanos, frente a diferentes soluções irrigadoras. Material e método Quarenta e cinco incisivos centrais superiores artificiais de três marcas comerciais nacionais (dentes "A", "B" e "C") e 15 incisivos humanos foram utilizados. As amostras foram seccionadas a 5 mm do ápice dentário. Os fragmentos radiculares foram fixados em resina para posterior teste de microdureza. Os ensaios da microdureza Knoop foram realizados em dois momentos: momento 1 - microdureza inicial; momento 2 - microdureza final, que foi feita após o uso das soluções irrigadoras (Cloreto de Sódio a 0,9%, Hipoclorito de Sódio a 2,5% e Gluconato de Clorexidina a 2%). As endentações deixadas na superfície da amostra foram mensuradas. O valor obtido para microdureza de cada amostra foi feita com base na média de três endentações. Para análise estatística, foram utilizados os testes ANOVA e Teste t pareado, com nível de significância de 5%. Resultado Os dentes artificiais "A" e "C" apresentaram valores inferiores de microdureza quando comparados ao dente humano (P = 0,05). Não houve diferença estatística entre os dentes artificiais "B" e o dente humano (P = 0,2428). Quanto ao uso das diferentes soluções irrigadoras, também não houve diferença na microdureza das peças dentárias. Conclusão Embora a solução irrigadora não tenha influenciado a microdureza, os dentes artificiais apresentaram valores de dureza inferiores aos do dente humano.

Abstract Introduction Artificial teeth have been used for preclinical teaching practice. However, the behavior of the same is not known in relation to the different procedures performed during a simulated endodontic treatment. Objective To evaluate the microhardness of replicates of human teeth, in front of different irrigating solutions. Material and method Forty-five artificial upper central incisors of three national trade marks (teeth "A", "B" and "C") and fifteen human incisors were used. Samples were sectioned 5 mm from the apex. The root fragments were fixed in resin for later microhardness test. The Knoop microhardness tests were performed in two moments: moment 1 - initial microhardness; moment 2 - final microhardness, which was done after the use of the irrigating solutions (0.9% sodium chloride, 2.5% sodium hypochlorite and 2% chlorhexidine gluconate). The indentations left on the sample surface were measured. The obtained value for microhardness of each sample was made based on the average of three indentations. ANOVA and Paired t-test were used for statistical analysis. Significance level of 5%. Result Artificial teeth "A" and "C" presented lower values ​​of microhardness when compared to human teeth (P = 0.05). There was no statistical difference between the artificial teeth "B" for the human (P = 0.2428). Regarding the use of different irrigation solutions, there was also no difference in the microhardness of dental pieces. Conclusion Although the irrigating solution did not influence the microhardness, the artificial teeth presented values ​​of hardness inferior to the human tooth.

Does Endodontic Re-Treatment in Primary Teeth Increase the Functional Tooth Retention? A Clinical, Retrospective, University-Based Study

Objective: To investigate the longevity of endodontic treatments and the survival of endodontic re-treatments performed in primary teeth. Material and Methods: The sample included endodontic treatments and re-treatments conducted in anterior and posterior primary teeth without sedation or general anesthesia among children attending a university dental service. Information collected retrospectively from clinical records was used for analyzing data. The Kaplan-Meier estimator test was used to analyze the longevity and survival of endodontic treatment and re-treatments, respectively. Results: A total of 73 patients with endodontic therapy in primary teeth were included in the study, and 116 teeth were analyzed. After one year, the longevity of endodontic treatments performed on primary teeth was 65.74% with an annual failure rate (AFR) of 34.2%. From 47 endodontic treatment failures, 14 teeth (29.8%) were endodontically re-treated. When the endodontic re-treatment was considered as survival, the longevity of treatments reached 68.06% with 31.9% of AFR after one year of follow-up. There was a significant increase in functional tooth retention in those patients that received an endodontic re-treatment (p<0.001). Retreatment provided an additional mean survival time of 8.3 months. Conclusion: Endodontic treatments performed in primary teeth presented a limited longevity. Endodontic re-treatment is a more conservative alternative for endodontically treated primary teeth that have failed and significantly increase tooth retention.

Radiopacidade de dentes artificiais para treinamento pré-clínico de endodontia / Artificial tooth radiopacity for preclinical endodontic training

Resumo Introdução Dentes artificiais têm sido utilizados para a prática odontológica e, segundo seus fabricantes, apresentam muita similaridade aos dentes humanos para treinamento. Objetivo Avaliar a radiopacidade de dentes endodônticos artificiais para uso em atividades de ensino e saber a percepção de docentes quanto à análise radiográfica. Material e método Trinta réplicas de incisivos centrais superiores de três marcas comerciais (Fábrica de Sorrisos, IM do Brasil e Real Dent) e um incisivo humano foram utilizados. Foram dispostos sobre um sensor radiográfico o dente humano e um dente artificial de cada empresa. As análises de radiopacidade foram feitas no programa Photoshop® em triplicata em quatro regiões distintas: porção central da coroa e nos terços cervical, médio e apical do canal. A percepção quanto à utilização dos dentes como instrumento prático de ensino foi avaliada por meio de um questionário aplicado a oito professores de endodontia. Para análise estatística dos valores de radiopacidade, foi utilizada a ANOVA, seguida do teste de Tukey. Foi empregado um nível de significância de 5%. Para análise do questionário, foram empregados métodos descritivos e por porcentagem de dados no que se refere à frequência das respostas. Resultado Houve diferença de radiopacidade entre os diferentes dentes testados em cada região analisada (p > 0,05). Na percepção dos professores com relação à utilização dos dentes no ensino, eles colocaram em ordem crescente os seguintes dentes para uso: IM do Brasil, Fábrica de Sorrisos, Real Dent e humano. Conclusão A radiopacidade dos dentes artificiais foi diferente do humano. O dente artificial da Fábrica de Sorrisos apresentou os maiores valores de radiopacidade. Contudo, os professores consideraram ideais para utilização no ensino apenas o dente humano e o dente da Real Dent.

Abstract Introduction Artificial teeth have been used for dental practice which, acoording to their manufactures, bear much similarity to human teeth for training. Objective To evaluate radiopacity of artificial endodontic teeth for use in teaching activities and to know the perception of teachers regarding radiographic analysis. Material and method Thirty replicates of upper central incisors of three trade marks (Fábrica de Sorrisos, IM do Brasil and Real Dent) and a human incisor were used. On a radiographic sensor, human tooth and one artificial tooth of each marks were arranged. Radiopacity analyzes were performed using Photoshop® in triplicate in four distinct regions: central portion of the crown and in the cervical, middle and apical thirds of the canal. The perception about the use of teeth as a practical teaching instrument was evaluated through a questionnaire applied to eight teachers of Endodontics. For statistical analysis of the radiopacity values ​​ANOVA was used, followed by the Tukey test. Significance level of 5%. For the analysis of the questionnaire were used descriptive methods and percentage of data regarding the frequency of responses. Result There was a difference in radiopacity between the different teeth tested, in each region analyzed (P > 0.05). In the teachers' perception regarding the use of teeth in teaching, the teachers placed the following teeth for use: IM do Brasil, Fábrica de Sorrisos, Real Dent and human. Conclusion The radiopacity of the artificial teeth was different from the human teeth. The artificial tooth of the Fábrica de Sorrisos presented the highest values ​​of radiopacity. The teachers considered ideal for use in teaching only the human teeth and the prototype Real Dent.

Antimicrobial action, pH, and tissue dissolution capacity of 2,5% sodium hypochlorite gel and solution / Ação antimicrobiana, pH, e capacidade de dissolução tecidual de gel e solução de hipoclorito de sódio 2,5%

Objective: to evaluate antimicrobial action, pH, and tissue dissolution capacity of 2.5% sodium hypochlorite (NaOCl) gel and solution. Methods: The 2.5% NaOCl gel was produced from a colloidal base. The test groups included 2.5% NaOCl gel and solution and the control groups included gel base and distilled water. The antimicrobial activity was evaluated by the broth dilution technique against Enterococcus faecalis (ATCC 29212) at 15 and 30 seconds and at 1, 5, and 10 minutes. To evaluate tissue dissolution capacity, 30 pulp fragments of bovine incisors were weighed, 10 for each test group and 5 for each control group before and after exposure to the chemical auxiliaries. The final mass percentage of each fragment was calculated. The pH of the substances was measured in triplicate through a digital pH meter. Results: pH levels of 13.08 and 9.75 were observed for 2.5% NaOCl solution and gel, respectively. The antimicrobial action of 2.5% NaOCl was the same for both solution and gel, for all tested times. The 2.5% NaOCl solution group showed higher tissue dissolution capacity (Kruskal-Wallis and Student-Newman-Keuls tests P<0.0001). Conclusions: The type of medium, either solution or gel, containing 2.5% NaOCl did not influence the antimicrobial action at any of the tested times. However, 2.5% NaOCl gel did not present tissue dissolution capacity

Objetivo: avaliar a ação antimicrobiana, pH e capacidade de dissolução tecidual promovida por hipoclorito de sódio (NaOCl) 2,5%, nas formas líquida e gel. Métodos: O gel de NaOCl 2,5% foi produzido a partir de base coloidal. Os grupos testes foram NaOCl 2,5% gel e solução e os grupos controle incluíram a base gel e água destilada. A ação antimicrobiana foi avaliada por meio de método de diluição em caldo, frente a Enterococcus faecalis (ATCC 29212) após 15 e 30 segundos, e também a 1, 5 e 10 minutos. Para o teste de diluição tecidual, 35 fragmentos de polpa bovina (sendo 10 para cada grupo teste e 5 para o grupo controle) foram pesadas antes e após a exposição aos auxiliares químicos. O percentual de massa final de cada fragmento foi calculada. O pH dos auxiliares químicos foi medido em pHmetro digital, em triplicata. Resultados: Valores de pH iguais a 13,08 e 9,75 foram observados para solução e para o gel de NaOCl, respectivamente. A ação antimicrobiana do NaOCl foi a mesma para o gel e a solução, em todos os períodos testados. Maior capacidade de dissolução tecidual foi obtida no grupo onde se utilizou a solução de NaOCl 2,5% (Testes de Kruskal-Wallis e Student-Newman-Keuls, P<0,0001). Conclusões: A apresentação na forma de gel ou de líquido do NaOCl 2,5% não modificou a ação antimicrobiana em qualquer um dos períodos testados. Porém, o gel de NaOCl 2,5% não demonstrou capacidade de dissolução tecidual.

Avaliação da formação de smear layer no preparo químico mecânico realizado com solução ou gel de hipoclorito de sódio a 2, 5% / Evaluation of smear layer formation in mechanical chemical preparation performed with 2. 5% sodium hypochloride solution or gel

Introdução: a formação de smear layer durante o preparo dos canais radiculares com o uso de hipoclorito de sódio solução já foi amplamente estudada; entretanto, na apresentação em gel não existem relatos na literatura. Objetivo: avaliar, em MEV, a formação de smear layer durante o preparo endodôntico, utilizando o NaOCl nas formas líquida e gel, associado ou não ao EDTA. Métodos: sessenta raízes palatinas de molares superiores ou distais de inferiores, com comprimento radicular padronizado em 15 mm, foram utilizadas. As amostras foram divididas em quatro grupos controle com n = 5 cada (soro fisiológico ou base gel, associados ou não ao EDTA) e quatro grupos testes com n = 10 cada, de acordo com a substância irrigadora empregada durante o preparo (solução ou gel de NaOCl a 2,5%, associados ou não ao EDTA). Os canais foram modelados e posteriormente clivados para análise em MEV (ampliação de 2000x). Imagens de eletromicrografias foram obtidas nos terços cervical, médio e apical. A presença e as características da smear layer formadas foram categorizadas. As imagens foram analisadas por dois avaliadores, previamente, calibrados. Após a análise de concordância (Kappa = 0,806) dos escores, os dados foram tratados com o uso do teste Kruskall-Wallis, complementado pelo teste de Comparações Múltiplas SNK. O nível de significância foi de 5%. Resultados: a utilização do soro fisiológico e do NaOCl líquido, associados à irrigação final com EDTA, apresentou os melhores resultados de limpeza. Com o uso do NaOCl gel e da base gel, sem associação ao EDTA, houve uma maior quantidade de resíduos sobre as paredes dentinárias. Além disso, independentemente da substância irrigadora testada, pode-se observar que houve uma melhor capacidade de remoção da smear layer no terço cervical em relação ao apical. Conclusões: observou-se formação de smear layer após o preparo do canal radicular associado ao NaOCl líquido ou gel. A aplicação de EDTA promoveu a remoção da smear layer produzida durante o preparo do canal.

Introduction: the formation of smear layer during the preparation of root canals with the use of sodium hypochlorite solution has been widely studied; however, in the gel presentation there aren't reports in the literature. Objective: to evaluate, in SEM, the formation of smear layer during endodontic preparation, using NaOCl in liquid and gel forms, associated or not with EDTA. Methods: sixty palatal roots of maxillary molars or distal roots of lower molars, with a root length of 15 mm, were used. The samples were divided into four control groups with n = 5 each (saline or gel base, associated or not with EDTA) and four test groups (n = 10 each) according to the irrigation substance used during the preparation (2.5% NaOCl solution or gel, associated or not with EDTA). The root canals were instrumented and later split for SEM analysis (2000x magnification). Electromicrographic images were obtained from the cervical, middle and apical thirds. The presence and characteristics of the smear layer formed were categorized. The images were analyzed by two previously calibrated evaluators. After the Kappa analysis (0.806), the data were treated using the Kruskall-Wallis test, complemented by the SNK Multiple Comparison Test. The level of significance was 5%. Results: the use of saline and liquid NaOCl, associated with final rinsing with EDTA, showed the best cleaning results. With the use of NaOCl gel and gel base, with no EDTA association, there was a greater amount of residues on the dentin surfaces. In addition, despite the irrigation substance tested, it can be observed that there was a better capacity of removal of the smear layer in the cervical third in relation to the apical. Conclusion: root canal instrumentation associated with NaOCl solution or gel EDTA produced smear layer. Smear layer was removed with the use of EDTA as a final flushing.

Analysis of cutting capacity, preparation time, and apical deviation after instrumentation of artificial curved canals with the waveone ® and reciproc ® reciprocating systems / Análise da capacidade de corte, tempo de prepare e desvio apical após a instrumentação de canais curvos artificiais com sistemas reciprocantes Waveone ® e Reciproc ®

ABSTRACT Objective To analyze cutting capacity, preparation time, and occurrence of apical deviation, after instrumentation of curved canals with reciprocating Primary WaveOne ® and R25 Reciproc ® systems. Methods Twenty simulated canals with 35° bends were randomly assigned to the Primary WaveOne ® or R25 Reciproc ® . The preparations were made by a single operator. The cutting capacity was assessed by the difference in weight (on an analytical balance) of the canals before and after preparation. The time needed for the preparation was analyzed. The canals were filled with India ink and photographed on a platform before and after the preparation to analyze the apical deviation to a 1 mm length. The images were superimposed in Photoshop ® and the measurement was performed with the ruler tool. Statistical analysis was performed using Student's t-test. The level of significance was set at 5%. Results The WaveOne ® Primary system was more effective (in terms of cutting capacity) but had a longer preparation time than the R25 Reciproc ® instrument. Apical deviation was the only variable that did not significantly differ between the two systems. Conclusion The WaveOne ® Primary had a higher cutting capacity than the R25 Reciproc ® . Both systems maintained the original canal path. The preparation time was shorter for the R25 Reciproc ® than the WaveOne ® Primary system.

RESUMO Objetivo Analisar a capacidade de corte, o tempo de preparo e a ocorrência de desvio apical, após a instrumentação de canais curvos com os sistemas reciprocantes WaveOne ® e Reciproc ® . Métodos Vinte canais simulados, com 35° de curvatura, foram randomicamente divididos para os dois sistemas. Os instrumentos utilizados foram o WaveOne ® Primary e o R25 Reciproc ® . Cada instrumento foi utilizado em um canal. Os preparos foram feitos por um único operador. Para análise da capacidade de corte, os canais foram pesados em balança analítica antes e após o preparo. A diferença na pesagem foi utilizada para aferição. O tempo para execução do preparo foi cronometrado e os valores obtidos foram analisados. Já para análise do desvio a 1 mm do comprimento de trabalho, antes e após o preparo, os canais foram preenchidos com tinta nanquim e fotografados em uma plataforma. As imagens foram sobrepostas no Photoshop ® e, com a ferramenta régua, foi realizada a medição. Resultados Para análise estatística foi utilizado o teste T de Student, com nível de significância de 5%. Na análise da capacidade de corte, o sistema WaveOne ® Primary foi mais eficaz que o instrumento R25 Reciproc ® , embora o seu tempo de preparo tenha sido maior. Apenas no critério, desvio apical, não se verificou diferença significativa entre os dois sistemas. Conclusão O WaveOne ® Primary apresentou uma maior capacidade de corte que o R25 Reciproc ® . Ambos os sistemas respeitaram a trajetória original do canal. O tempo de preparo do R25 Reciproc ® foi menor que o WaveOne ® Primary.

Evaluation of the tip of standardized D0 gutta percha cones of four Rotary systems, by means of an endodontic ruler / Avaliação da adaptação de cones estandardizados de guta-percha de quatro sistemas mecanizados por meio de uma régua endodôntica calibradora

ABSTRACT Objective : This study aimed to evaluate the D0 diameter of standardized gutta-percha cones for four mechanized systems: ProTaper Universal®, Mtwo®, Wave One® and Reciproc®. Methods: An endodontic calibrator ruler was used to measure the D0 diameter of 60 main cones of the above systems. Measurements were made according 3 scores as follows: gutta-percha cone fits exactly into the same hole as the endodontic ruler gauge (score 1), cone falls short of the ruler gauge whole size (score 2); or exceeding the ruler gauge hole size (score 3). The diameters D0 obtained were compared with the values reported by manufacturers. All data were analyzed by means of T Test, at 1% level of significance. Results: The average value measured was significantly higher than the measures established by manufacturers (p <0.001). Conclusion : The gutta-percha cones of ProTaper Universal® systems Mtwo®, Wave One® and Reciproc® were not standardized, except for R40 cone of the Reciproc® system (Reciproc®). The trend was for variation in the D0 Diameter towards increasing measurement values.

RESUMO Objetivo: Avaliar o diâmetro D0 de cones estandardizados de guta-percha de quatro sistemas mecanizados: ProTaper Universal®, Mtwo®, Wave One® e Reciproc® . Métodos: Por meio de uma régua endodôntica calibradora, foi aferido o diâmetro D0 de sessenta cones principais dos sistemas supracitados. A aferição foi realizada de acordo com os três escores a seguir: o cone de guta-percha se adapta exatamente no mesmo calibre de orifício da régua endodôntica (escore 1), o cone fica aquém ao calibre de orifício da régua (escore 2) ou além do respectivo calibre do orifício da régua (escore 3). Os diâmetros em D0 obtidos foram comparados aos valores divulgados pelos fabricantes. Todos os dados foram tratados por meio do Teste T, ao nível de significância de 1%. Resultados: As médias aferidas foram significativamente maiores do que as medidas estabelecidas pelos fabricantes (p<0,001). Somente os cones R40 do sistema Reciproc® estiveram no padrão. Conclusão: Os cones de guta-percha dos sistemas ProTaper Universal®, Mtwo®, Wave One® e Reciproc® não apresentam padronização, à exceção do cone R40 ( Reciproc® ). Houve uma tendência de variação do diâmetro D0 para uma maior medida.

Analysis of root canal organic tissue dissolution capacity according to the type of irrigation solution and agitation technique

Aim: To analyze the root canal organic tissue dissolution capacity promoted by irrigating solutions,with or without the use of different agitation techniques. Methods: Bovine pulp tissue fragmentswere initially weighed. The following irrigating solutions were tested: 2.5% sodium hypochlorite, 2%chlorhexidine digluconate solution, and distilled water. The irrigating protocols were: immersion,mechanical agitation with endodontic files, and ultrasonic or sonic systems (Endoactivactor®and Easy Clean®). At the end of the protocols, the pulps were weighed to determine their finalweight. For comparison, the average percentage of tissue dissolution in relation to the groups wasanalyzed using the Kruskal-Wallis nonparametric test complemented by multiple comparisonstest. The significance level was set at 5%. Results: Among the irrigation solutions, 2.5% sodiumhypochlorite showed a higher dissolving power than 2% chlorhexidine digluconate and distilled water.Furthermore, ultrasonic and sonic systems were more effective irrigating protocols than immersionand mechanical agitation with endodontic files. Conclusions: The combination of sodium hypochloritewith an agitation system promotes a greater degree of tissue degradation.

Influence of atmospheric temperature on the occurrence of irreversible pulpitis clinical cases

Introduction and Objective: The present study aimed to examine the correlation between atmospheric temperature and the occurrence of irreversible pulpitis. Material and methods: Data was collected from the Department of Dentistry, Moinhos de Vento Hospital, Porto Alegre between July 2011 and December 2012. A total of 52 pulpitis clinical cases were examined in 529 days in this study. Data on the atmospheric temperature in Porto Alegre on each day was collected from the Porto Alegre Meteorology Institute. Results and Conclusion: Correlation analysis of the temperature data and pulpitis cases was conducted using Student's t-test, with a significance level of 5%. Although no correlation was observed between the occurrence of irreversible pulpitis and atmospheric temperature, the incidence rates were higher on days when the average temperature was greater than 25ºC.

LPS levels in root canals after the use of ozone gas and high frequency electrical pulses

Abstract The present study aims to verify the effect of ozone gas (OZY® System) and high frequency electric pulse (Endox® System) systems on human root canals previously contaminated with Escherichia colilipopolysaccharide (LPS). Fifty single-rooted teeth had their dental crowns removed and root lengths standardized to 16 mm. The root canals were prepared up to #60 hand K-files and sterilized using gamma radiation with cobalt 60. The specimens were divided into the following five groups (n = 10) based on the disinfection protocol used: OZY® System, one 120-second-pulse (OZY 1p); OZY® System, four 24-second-pulses (OZY 4p); and Endox® System (ENDOX). Contaminated and non-contaminated canals were exposed only to apyrogenic water and used as positive (C+) and negative (C-) controls, respectively. LPS (O55:B55) was administered in all root canals except those belonging to group C-. After performing disinfection, LPS samples were collected from the canals using apyrogenic paper tips. Limulus Amoebocyte Lysate (LAL) was used to quantify the LPS levels, and the data obtained was analyzed using one-way ANOVA. The disinfection protocols used were unable to reduce the LPS levels significantly (p = 0.019). The use of ozone gas and high frequency electric pulses was not effective in eliminating LPS from the root canals.

Evaluation of graduate dental students' knowledge on the therapeutic approach of dental avulsion

Introduction and Objetive : Introduction and Objective: The present study aimed to evaluate the knowledge level of students graduate in Dentistry of São Leopoldo Mandic/SP - Porto Alegre/RS on the therapeutic approach in cases of dental avulsion. Material and methods: For this, we applied a questionnaire to graduate students. Of the 214 students enrolled at the institution, 159 (74%) answered the questions. Results and Conclusion: Through analysis of the responses, it could be observed that, while 99.37% of participants have already received instructions about the subject, there was significant variability of opinions. With the application of Chi-square test, at a significance level of 5%, it could be observed that there was no significant difference in responses regarding to the time of graduation. As for the type of splinting, the professionals who graduated between 5 to 10 years were associated with the use of semi-rigid splint and those who graduate after more than 10 years with the rigid splint.

Analysis of the time required for dissolving the pulp tissue according to different methods of sodium hypochlorite activation

Introduction and Objective:To analyze the time required to dissolute the pulp tissue under different methods of sodium hypochlorite activation. Material and methods: 30 bovine pulp fragments, with an approximate volume of 45 ± 5 mg were divided into three experimental groups (n = 10). In group 1, only the fragments were immersed in 15 ml of 2.5% sodium hypochlorite. In group 2, the irrigant was manually stirred with an endodontic instrument type K size 40. In group 3, we used the ultrasonic insert n.39, driven by ultrasound device Jet Sonic Total. The time required for total dissolution of bovine tissue was measured and recorded for statistical analysis. Results and Conclusion: According to analysis of variance (Anova), with p<0.05, Group 1 showed significantly higher dissolution time than Groups 2 and 3. Moreover, no difference between the use of ultrasound and manual activation of the irrigating solution was found.

QMix® irrigant reduces lipopolysacharide (LPS) levels in an in vitro model

AbstractThe presence of endotoxin inside the root canal has been associated with periapical inflammation, bone resorption and symptomatic conditions.Objectives To determine, in vitro, the effect of QMix® and other three root canal irrigants in reducing the endotoxin content in root canals.Material and Methods Root canals of single-rooted teeth were prepared. Samples were detoxified with Co-60 irradiation and inoculated with E. coli LPS (24 h, at 37°C). After that period, samples were divided into 4 groups, according to the irrigation solution tested: QMix®, 17% EDTA, 2% chlorhexidine solution (CHX), and 3% sodium hypochlorite (NaOCl). LPS quantification was determined by Limulus Amebocyte Lysate (LAL) assay. The initial counting of endotoxins for all samples, and the determination of LPS levels in non-contaminated teeth and in contaminated teeth exposed only to non-pyrogenic water, were used as controls.Results QMix® reduced LPS levels, with a median value of 1.11 endotoxins units (EU)/mL (p<0.001). NaOCl (25.50 EU/mL), chlorhexidine (44.10 EU/mL) and positive control group (26.80 EU/mL) samples had similar results. Higher levels were found with EDTA (176.00 EU/mL) when compared to positive control (p<0.001). There was no significant difference among EDTA, NaOCl and CHX groups. Negative control group (0.005 EU/mL) had statistically significant lower levels of endotoxins when compared to all test groups (p<0.001).Conclusion QMix® decreased LPS levels when compared to the other groups (p<0.001). 3% NaOCl, 2% CHX and 17% EDTA were not able to significantly reduce the root canal endotoxins load.