Abstract This ecological study assessed the impact of the COVID-19 pandemic on completed treatments (CTs) and referrals during urgent dental visits to primary health care units in Brazil, and their associations with socioeconomic, geodemographic, and pandemic index factors in Brazilian municipalities. The difference in rates of procedures 12 months before and during the pandemic was calculated. Data were extracted at baseline from health information systems of all municipalities that provided urgent dental care (n = 5,229 out of 5,570). Multiple logistic regression predicted the factors associated with referrals and CTs. The number of dental urgencies increased from 3,987.9 to 4,272.4 per 100,000 inhabitants. The rates of referrals decreased in 44.1% of the municipalities, while 53.9% had lower rates of CTs. Municipalities with a greater number of oral health teams in the primary health care system (OR = 1.52, 95%CI:1.21–1.91) and with specialized services (OR = 1.80, 95%CI:1.50–2.16) were more likely to decrease referrals during the pandemic. Higher HDI and GDP per capita were associated with a larger decrease in referrals and smaller decrease in CTs. The calamity generated by the long pandemic period resulted in a greater demand for urgent visits. Less developed and larger cities seem to have been more likely to not complete treatments during urgent visits in primary dental care units in times of calamity. Primary dental care offices in smaller and less developed municipalities should be better equipped to provide appropriate assistance and to improve the problem-solving capacity of dental services during emergencies.

Abstract: This study aimed to compare the physicochemical properties of MTA Angelus (MTA-A), MTA Repair HP (MTA-HP), and Biodentine (BD). Setting times (n = 7) were determined in accordance with ASTM C266–15. Solubility (n = 11), pH (n = 10), and calcium ion release (n = 10) were evaluated up to 28 days in accordance with ANSI/ADA specification no. 57. Radiopacity was assessed by ANSI/ADA (n = 10) and the tissue simulator method (n = 10). In both methods, the specimens were radiographed using an aluminum stepwedge and the digital radiographs were analyzed in Adobe Photoshop, determining the mean grayscale pixel values of the materials, of the 3-mm aluminum stepwedge, and of the dentin, the latter of which was analyzed on the tissue simulator. The data obtained from each test were statistically analyzed and compared (p < 0.05). MTA-A presented longer final setting time compared with the other materials. There were no significant differences in the mass values of materials during the experiment. All materials presented an alkaline pH. BD promoted greater calcium ion release in most of the experimental periods. All materials presented appropriate radiopacity. BD showed lower radiopacity than MTA-A in the tissue simulator method. All groups presented higher radiopacity in the tissue simulator when compared with the ANSI/ADA method. MTA-A, MTA-HP, and BD showed appropriate physicochemical properties and radiopacity, and were considered suitable to be used in clinical practice.

Abstract Clinical decision-making tends to be based on what clinicians have been taught during undergraduate and graduate programs. The aim of the present study was to assess the clinical approach and to identify the factors that influence the decision-making for dental pulp exposure among graduate students and coordinating professors in endodontics programs offered at Brazilian universities. The study used a mail-out survey developed in the Qualtrics platform, based on seven clinical reports in which dental pulp exposure was evidenced. Descriptive statistics showing vital pulp therapy (VPT) and root canal treatment (RCT) were calculated for each clinical report. Data on the participants’ (n = 113) profile and variables related to clinical and radiographic characteristics of the cases were evaluated as to their potential to affect decision-making and analyzed by logistic regression (p < 0.05). VPT was likely to be indicated in cases of patients with immature teeth (OR = 0.017; 95%CI = 0.004 -0.073). RCT indications were related to the presence of symptoms (OR = 5.326; 95%CI = 1.429–19.852) and old age (OR = 21.057; 95%CI=6.809–65.120). In pulp exposure secondary to trauma, time of pulp exposure was significantly associated with RCT indication (OR=3.267; 95%CI=1.332–8.012). The present study demonstrated that patient age, root development, and symptom features were the main factors affecting participants’ decision-making.

Este estudo ecológico descreveu como a pandemia da COVID-19 e o desenvolvimento socioeconômico afetaram o uso da assistência odontológica de urgência (AOU) e seu perfil. Comparamos taxas de AOU para cada 100 mil habitantes antes (de março a junho de 2019) e durante (de março a junho de 2020) a pandemia da COVID-19 em 4.062 municípios brasileiros. Os dados foram coletados de fontes oficiais. As taxas de mortalidade e internação pela COVID-19 indicaram níveis restritivos de lockdown e Índices de Desenvolvimento Humano (IDH) indicou o nível de desenvolvimento socioeconômico. Foram utilizadas regressões logísticas múltiplas e risco relativo de excesso devido à interação (RERI) para análises estatísticas. O teste t de Student foi usado para comparar alterações no perfil das causas e procedimentos da AOU nos dois períodos. As taxas de AOU foram menores em 69,1% dos municípios e associadas a IDH maior (OR = 1,20; IC95%: 1,01; 1,42). A mortalidade apresentou uma razão de chances de 0,88 (IC95%: 0,73; 1,06) para municípios com IDH < 0,70 e de 1,45 (IC95%: 1,07; 1,97) para municípios com IDH > 0,70. O RERI entre IDH e COVID-19 foi de 0,13 (p < 0,05). Os municípios com maior cobertura de atenção primária à saúde apresentaram menor redução nas suas taxas de emergência. Procedimentos endodônticos e dor dentária foram os fatores mais frequentes antes e durante a pandemia. O percentual de AOUs aumentou devido à dor, danos nos tecidos moles, vedação temporária e procedimentos cirúrgicos. Variáveis socioeconômicas afetaram as taxas de AOU durante o período mais restritivo da pandemia da COVID-19 e devem ser incluídas no planejamento de ações de saúde em emergências futuras.

This ecological study described the effect of the COVID-19 pandemic and socioeconomic development on the use and profile of urgent dental care (UDC). UDC rates per 100,000 inhabitants before (from March to June 2019) and during (from March to June 2020) the COVID-19 pandemic in 4,062 Brazilian municipalities were compared. Data were collected from official sources. COVID-19 mortality and hospitalization rates were indicative of levels of lockdown and Human Development Index (HDI) indicated socioeconomic development. Multiple logistic regression and relative excess risk due to interaction (RERI) were used for statistical analyses. The Student t-test was used to compare changes in the profile of UDC causes and procedures in the two periods. Lower UDC rates were found in 69.1% of municipalities and were associated with higher HDI (OR = 1.20; 95%CI: 1.01; 1.42). Mortality had OR = 0.88 (95%CI: 0.73; 1.06) for municipalities with HDI < 0.70 and OR = 1.45 (95%CI: 1.07; 1.97) for municipalities with HDI > 0.70. RERI between HDI and COVID-19 was 0.13 (p < 0.05). Municipalities with greater primary health care coverage had a smaller reduction in emergency rates. Endodontic treatment and dental pain were the most frequent factors both before and during the pandemic. The percentage of UDCs due to pain and soft tissue damage, as well as temporary sealing and surgical procedures, increased. Socioeconomic variables affected UDC rates during the most restrictive period of the COVID-19 pandemic and should be considered in the planning of health actions in future emergencies.

Este estudio ecológico describió el efecto de la pandemia de COVID-19 y el desarrollo socioeconómico en el uso y el perfil de la atención odontológica de urgencia (AOU). Se compararon las tasas de AOU por cada 100.000 habitantes antes de la pandemia de COVID-19 (de marzo a junio de 2019) y durante la pandemia de COVID-19 (de marzo a junio de 2020) en 4.062 municipios brasileños. Los datos se recogieron de fuentes oficiales. Las tasas de mortalidad y hospitalización de COVID-19 fueron indicativas de niveles restrictivos de desarrollo socioeconómico e Índice de Desarrollo Humano (IDH). Para los análisis estadísticos se utilizó la regresión logística múltiple y el exceso de riesgo relativo (ERR) debido a la interacción. Se utilizó la prueba t de Student para comparar los cambios en el perfil de las causas y los procedimientos de AOU en los dos períodos. Las tasas de AOU fueron menores en el 69,1% de los municipios y se asociaron con un IDH más alto (OR = 1,20; IC95%: 1,01; 1,42). La mortalidad tuvo una OR de 0,88 (IC95%: 0,73; 1,06) para los municipios con IDH < 0,70 y de 1,45 (IC95%: 1,07; 1,97) para los municipios con IDH > 0,70. El ERR entre el IDH y el COVID-19 fue de 0,13 (p < 0,05). Los municipios con mayor cobertura de atención primaria tuvieron una menor reducción de las tasas de urgencia. Los procedimientos de endodoncia y la causa del dolor dental fueron los factores más frecuentes tanto antes como durante la pandemia. Aumentó el porcentaje de AOU por dolor y daños en los tejidos blandos, así como el sellado temporal y los procedimientos quirúrgicos. Las variables socioeconómicas afectaron a las tasas de AOU durante el periodo más restrictivo de la pandemia de COVID-19 y deberían incluirse en la planificación de las acciones sanitarias en futuras emergencias.

Este estudo ecológico descreveu como a pandemia da COVID-19 e o desenvolvimento socioeconômico afetaram o uso da assistência odontológica de urgência (AOU) e seu perfil. Comparamos taxas de AOU para cada 100 mil habitantes antes (de março a junho de 2019) e durante (de março a junho de 2020) a pandemia da COVID-19 em 4.062 municípios brasileiros. Os dados foram coletados de fontes oficiais. As taxas de mortalidade e internação pela COVID-19 indicaram níveis restritivos de lockdown e Índices de Desenvolvimento Humano (IDH) indicou o nível de desenvolvimento socioeconômico. Foram utilizadas regressões logísticas múltiplas e risco relativo de excesso devido à interação (RERI) para análises estatísticas. O teste t de Student foi usado para comparar alterações no perfil das causas e procedimentos da AOU nos dois períodos. As taxas de AOU foram menores em 69,1% dos municípios e associadas a IDH maior (OR = 1,20; IC95%: 1,01; 1,42). A mortalidade apresentou uma razão de chances de 0,88 (IC95%: 0,73; 1,06) para municípios com IDH < 0,70 e de 1,45 (IC95%: 1,07; 1,97) para municípios com IDH > 0,70. O RERI entre IDH e COVID-19 foi de 0,13 (p < 0,05). Os municípios com maior cobertura de atenção primária à saúde apresentaram menor redução nas suas taxas de emergência. Procedimentos endodônticos e dor dentária foram os fatores mais frequentes antes e durante a pandemia. O percentual de AOUs aumentou devido à dor, danos nos tecidos moles, vedação temporária e procedimentos cirúrgicos. Variáveis socioeconômicas afetaram as taxas de AOU durante o período mais restritivo da pandemia da COVID-19 e devem ser incluídas no planejamento de ações de saúde em emergências futuras.

This ecological study described the effect of the COVID-19 pandemic and socioeconomic development on the use and profile of urgent dental care (UDC). UDC rates per 100,000 inhabitants before (from March to June 2019) and during (from March to June 2020) the COVID-19 pandemic in 4,062 Brazilian municipalities were compared. Data were collected from official sources. COVID-19 mortality and hospitalization rates were indicative of levels of lockdown and Human Development Index (HDI) indicated socioeconomic development. Multiple logistic regression and relative excess risk due to interaction (RERI) were used for statistical analyses. The Student t-test was used to compare changes in the profile of UDC causes and procedures in the two periods. Lower UDC rates were found in 69.1% of municipalities and were associated with higher HDI (OR = 1.20; 95%CI: 1.01; 1.42). Mortality had OR = 0.88 (95%CI: 0.73; 1.06) for municipalities with HDI < 0.70 and OR = 1.45 (95%CI: 1.07; 1.97) for municipalities with HDI > 0.70. RERI between HDI and COVID-19 was 0.13 (p < 0.05). Municipalities with greater primary health care coverage had a smaller reduction in emergency rates. Endodontic treatment and dental pain were the most frequent factors both before and during the pandemic. The percentage of UDCs due to pain and soft tissue damage, as well as temporary sealing and surgical procedures, increased. Socioeconomic variables affected UDC rates during the most restrictive period of the COVID-19 pandemic and should be considered in the planning of health actions in future emergencies.

Este estudio ecológico describió el efecto de la pandemia de COVID-19 y el desarrollo socioeconómico en el uso y el perfil de la atención odontológica de urgencia (AOU). Se compararon las tasas de AOU por cada 100.000 habitantes antes de la pandemia de COVID-19 (de marzo a junio de 2019) y durante la pandemia de COVID-19 (de marzo a junio de 2020) en 4.062 municipios brasileños. Los datos se recogieron de fuentes oficiales. Las tasas de mortalidad y hospitalización de COVID-19 fueron indicativas de niveles restrictivos de desarrollo socioeconómico e Índice de Desarrollo Humano (IDH). Para los análisis estadísticos se utilizó la regresión logística múltiple y el exceso de riesgo relativo (ERR) debido a la interacción. Se utilizó la prueba t de Student para comparar los cambios en el perfil de las causas y los procedimientos de AOU en los dos períodos. Las tasas de AOU fueron menores en el 69,1% de los municipios y se asociaron con un IDH más alto (OR = 1,20; IC95%: 1,01; 1,42). La mortalidad tuvo una OR de 0,88 (IC95%: 0,73; 1,06) para los municipios con IDH < 0,70 y de 1,45 (IC95%: 1,07; 1,97) para los municipios con IDH > 0,70. El ERR entre el IDH y el COVID-19 fue de 0,13 (p < 0,05). Los municipios con mayor cobertura de atención primaria tuvieron una menor reducción de las tasas de urgencia. Los procedimientos de endodoncia y la causa del dolor dental fueron los factores más frecuentes tanto antes como durante la pandemia. Aumentó el porcentaje de AOU por dolor y daños en los tejidos blandos, así como el sellado temporal y los procedimientos quirúrgicos. Las variables socioeconómicas afectaron a las tasas de AOU durante el periodo más restrictivo de la pandemia de COVID-19 y deberían incluirse en la planificación de las acciones sanitarias en futuras emergencias.

Abstract Objectives This study aimed to investigate patterns and risk factors related to the feasibility of achieving technical quality and periapical healing in root canal non-surgical retreatment, using regression and data mining methods. Methodology This retrospective observational study included 321 consecutive patients presenting for root canal retreatment. Patients were treated by graduate students, following standard protocols. Data on medical history, diagnosis, treatment, and follow-up visits variables were collected from physical records and periapical radiographs and transferred to an electronic chart database. Basic statistics were tabulated, and univariate and multivariate analytical methods were used to identify risk factors for technical quality and periapical healing. Decision trees were generated to predict technical quality and periapical healing patterns using the J48 algorithm in the Weka software. Results Technical outcome was satisfactory in 65.20%, and we observed periapical healing in 80.50% of the cases. Several factors were related to technical quality, including severity of root curvature and altered root canal morphology (p<0.05). Follow-up periods had a mean of 4.05 years. Periapical lesion area, tooth type, and apical resorption proved to be significantly associated with retreatment failure (p<0.05). Data mining analysis suggested that apical root resorption might prevent satisfactory technical outcomes even in teeth with straight root canals. Also, large periapical lesions and poor root filling quality in primary endodontic treatment might be related to healing failure. Conclusion Frequent patterns and factors affecting technical outcomes of endodontic retreatment included root canal morphological features and its alterations resulting from primary endodontic treatment. Healing outcomes were mainly associated with the extent of apical periodontitis pathological damages in dental and periapical tissues. To determine treatment predictability, we suggest patterns including clinical and radiographic features of apical periodontitis and technical quality of primary endodontic treatment.

Abstract: Biodentine in endodontic practice has been widely investigated, but comprehensive histological descriptions of degenerative and inflammatory responses are not covered in most of the studies that compare pulp capping materials. This study aimed to evaluate pulpal responses to mineral trioxide aggregate (MTA Angelus) and Biodentine, focusing on mineralized barrier formation and on inflammatory and degenerative events. 80 male Wistar rats were assigned to 5 groups, according to the materials used for pulp capping and coronal sealing (n=8 per group/period). The lower first molars were mechanically exposed, capped with either MTA or Biodentine, and restored with silver amalgam. In an additional test group, the teeth were capped and sealed with Biodentine. The teeth capped with gutta-percha and restored with silver amalgam served as positive control, whereas untreated teeth served as negative control. Pulpal responses and coronal sealing were evaluated after 14 or 21 days. Data was statistically analyzed by the Kruskal-Wallis and Dunn's post hoc tests (p<0.05). Biodentine and MTA presented satisfactory results, showing a milder inflammatory response (p<0.0001) and more pronounced formation of mineralized barrier (p<0.0001) compared to the teeth capped with gutta-percha. As a restorative material, Biodentine kept coronal sealing in only 37.5% of the samples. Biodentine showed favorable properties in vital pulp therapy, being similar to MTA. However, it was not effective in protecting dental pulp from microleakage during the experimental period.

Resumo Um dos requisistos para a aplicação clínica de materiais endodônticos é apresentar comportamento biológico satisfatório. Neste estudo, as respostas do tecido conjuntivo a cimentos endodônticos à base de silicone (GuttaFlow 2), resina epóxica (AH Plus) e óxido de zinco e eugenol (Endofill) foram comparadas. Doze ratos Wistar tiveram tubos de polietileno (4 em cada animal) contendo um dos materiais e tubos vazios (controle negativo) implantados no tecido conjuntivo subcutâneo. Os tubos foram randomicamente posicionados pelo menos 2 cm distantes entre si e da espinha dorsal do animal. Amostras de tecido contendo os implantes foram processadas para análise histológica após 7 e 60 dias (n=6 animais por período). Células inflamatórias, condensação fibrosa e formação de abscesso foram classificadas em escores de acordo com sua intensidade. O teste Friedman, seguido por post hoc de Dunn, foi empregado para comparar os cimentos. O teste de Mann-Witney U foi empregado para verificar diferenças entre os períodos experimentais em cada grupo (p<0,05). Após 7 dias, a maior parte dos parâmetros histológicos não mostrou diferenças estatísticas entre os grupos. O cimento Endofill promoveu escores mais altos que os outros materiais para a variável células gigantes (p<0,05), além de apresentar um maior número de amostras com formação de abscesso. O GuttaFlow 2 tendeu a apresentar infiltrado inflamatório menos intenso comparado aos outros materiais. Após 60 dias, não houve diferenças estatisticamente significantes entre os grupos na maioria dos parâmetros avaliados. Entretanto, observou-se que o EndoFill apresentou escores mais altos para os macrófagos em comparação ao controle (p<0,05) e que o GuttaFlow 2 apresentou tendência a escores mais baixos que os demais materiais para as variáveis neutrófilos e abscesso. O GuttaFlow 2 apresentou propriedades biológicas apropriadas e pode ser considerado adequado para a prática clínica.

Abstract Satisfactory biological behavior is a necessary requirement for clinical application of endodontic materials. In this study, the connective tissue responses to silicone (GuttaFlow 2), epoxy resin (AH Plus) and zinc oxide and eugenol (Endofill) based sealers were compared. Twelve Wistar rats had polyethylene tubes (four per animal) containing one of the tested sealers and empty tubes (negative control) implanted in their subcutaneous tissue. The tubes were randomly placed 2 cm from the spine and at least 2 cm apart from one another. Tissue samples with implants were processed for histological analysis after 7 or 60 days (n=6 animals per period). Inflammatory cells, fibrous condensation and abscess were scored according to their intensity. Friedman, followed by Dunn's post hoc, was used to compare sealers. Differences between the two experimental periods were verified using Mann-Witney U test (p<0.05). At 7 days, most of the histological parameters showed no significant differences amongst groups. Endofill group scored higher than the others for giant cells (o<0.05) and promoted a greater number of samples presenting abscess formation. GuttaFlow 2 tended to show a less intense inflammatory infiltrate compared to the other materials. At 60 days, there were no significant differences between groups in most of the histological parameters evaluated. However, it was observed that Endofill scored higher for macrophages (p<0.05) compared to the control group, and GuttaFlow 2 tended to present lower scores than the others for neutrophils and abscess. GuttaFlow 2 showed proper biological behavior and should be considered adequate for clinical practice.

Abstract The aim of this study was to evaluate whether the modification in the silver component is capable of providing GuttaFlow 2 with antibacterial activity against Enterococcus faecalis compared with epoxy resin-based (AH Plus) and zinc oxide and eugenol-based (Endofill) sealers. The antibacterial activity was evaluated using a reference strain of E. faecalis (ATCC 29212). Freshly mixed sealers were subjected to the agar diffusion test (ADT), while the direct contact test (DCT) was performed after materials setting. ADT results were obtained through measurements, in millimeters, of the inhibition zones promoted by the materials, using a digital caliper. In DCT, values of CFU/mL promoted by the three sealers were compared in three experimental periods (1 min, 1 h, and 24 h). The data were analyzed using Kruskal-Wallis and Dunn post-hoc tests (p < 0.05). In both ADT and DCT, GuttaFlow 2 presented no effect against E. faecalis, while Endofill and AH Plus showed similar inhibition zones. Endofill was the only material capable of reducing bacterial growth in DCT. In conclusion, modifications in the silver particle of GuttaFlow 2 did not result in a sealer with antibacterial effect against E. faecalis.

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.

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.

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 withEscherichia 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.

Dens invaginatus é uma malformação dentária já bem reconhecida, que provavelmente resulta de uma invaginação do órgão do esmalte para dentro da papila dentária durante o desenvolvimento do dente em questão. O tratamento endodôntico de dentes invaginados pode ser um desafio devido às dificuldades de acesso aos canais radiculares e também devido à complexidade da morfologia interna. Este artigo apresenta o manejo endodôntico e o acompanhamento de um caso raro de segundo pré-molar inferior direito com dens invaginatus Tipo III de Oehlers. O resultado do teste de sensibilidade pulpar ao frio foi positivo para este dente, mas o mesmo estava associado a uma fístula e lesão periapical. Relata-se o tratamento de canal deste dente associado à cirurgia periapical, enfatizando a importância de um correto diagnóstico e plano de tratamento, utilizando a tomografia computadorizada de feixe cônico (TCFC). Este relato de caso mostra reparo periapical adequado 6 meses após a combinação dos tratamentos não-cirúrgico e cirúrgico. Mostra também que a TCFC é um importante exame auxiliar para evitar erros no diagnóstico e posterior tratamento de anomalias dentárias.

Dens invaginatus is a well-known malformation of teeth, which probably results from an invagination of enamel organ into dental papilla during tooth development. The endodontic treatment of invaginated teeth may be challenging due to difficulties in accessing the root canals and also due to complex variations of internal morphology. This article presents the endodontic management and follow-up in a rare case of right mandibular second premolar with Oehlers' type III dens invaginatus. The result of cold pulp testing was positive for this tooth but it was associated to a sinus tract and periapical lesion. Herein, it is described the root canal therapy of this tooth combined with periapical surgery, emphasizing the importance of proper diagnosis and planning by using cone beam computed tomography (CBCT). This case report presents the proper periapical healing 6 months after the combination of nonsurgical and surgical treatments. It also shows that CBCT is an important auxiliary examination to avoid errors in diagnosis and subsequent treatment of dental anomalies.

OBJETIVO: O objetivo desse artigo é descrever três casos clínicos de dentes com rizogênese incompleta e necrose pulpar tratados com agregado trióxido mineral (MTA) para obtenção de barreira de selamento apical. DESCRIÇÃO DOS CASOS: Todos os casos relatados apresentaram interrupção da formação radicular como consequência da necrose pulpar. Os canais foram instrumentados utilizando gel de clorexidina a 2% como substância química auxiliar e medicados com pasta de hidróxido de cálcio e clorexidina, a qual foi mantida nos canais por uma semana. Em uma segunda consulta, a porção apical dos canais foi selada com barreira apical de MTA, com espessura de aproximadamente 3-4 mm. As demais porções dos canais foram obturadas com técnica de plastificação termomecânica da guta-percha, utilizando cimento à base de óxido de zinco e eugenol. Controle pós-operatório de 6 meses e 1 ano mostraram resposta radiográfica satisfatória e ausência de sintomas. CONCLUSÃO: Atualmente, MTA apresenta-se como uma opção interessante para casos de rizogênese incompleta e necrose pulpar, apresentando como vantagem o menor tempo de tratamento requerido.

PURPOSE: The purpose of this article is to present three clinical cases of infected immature teeth that were treated by using mineral trioxide aggregate (MTA) as an apical plug. CASES DESCRIPTION: All cases underwent premature interruption of root development as consequence of pulp necrosis. Root canals were instrumented by using chlorhexidine gel 2% (CHX) as auxiliary chemical substance. A paste of calcium hydroxide and CHX was kept for one week as intracanal dressing. In a second appointment, the apical portion of the canals (3-4 mm) was filled with MTA. The remaining portions of the root canals were then obturated by the thermomechanical technique by utilizing gutta-percha condensers and a zinc oxide and eugenol-based root canal sealer. Follow-up periods at both 6 months and 1 year showed radiographic favorable response and absence of symptoms. CONCLUSION: MTA seems to be nowadays, an interesting option of treatment for cases of immature teeth with the advantage of shorter treatment approaches.

OBJETIVO: A reabsorção radicular interna inflamatória é uma condição rara caracterizada por progressiva perda de substância dentária, que se inicia nas paredes do canal radicular. Geralmente o processo é assintomático e diagnosticado em exame radiográfico de rotina. O presente relato de caso mostra o tratamento de um caso de lesão periapical e reabsorção interna apical que atingiu a superfície radicular externa. DESCRIÇÃO DO CASO: Um paciente do sexo masculino de 16 anos foi encaminhado para tratamento odontológico de rotina para reabilitação oral. O exame radiográfico mostrou uma lesão de reabsorção no terço apical e lesão periapical no dente 21. O preparo coronário foi realizado e hidróxido de cálcio foi colocado por duas semanas. Um tampão com MTA branco foi condensado na cavidade da reabsorção e então o canal foi obturado com guta-percha e cimento AH Plus. As radiografias de acompanhamento mostraram resolução satisfatória. CONCLUSÃO: Este caso mostrou os resultados do tratamento com tampão apical de MTA. A técnica evitou um procedimento invasivo e apresentou algumas vantagens, tais como propriedades biológicas dos materiais e capacidade de selamento.

PURPOSE: Internal inflammatory root resorption is a rare condition, characterized by progressive loss of tooth substance which starts on the root canal wall. Usually the process is asymptomatic and diagnosed upon routine radiographic examination. The following report shows the treatment of a case of periapical lesion and apical internal resorption that reached the external root surface. CASE DESCRIPTION: A 16 year-old male was referred for a routine dental treatment for oral rehabilitation. Radiographic examination showed a resorptive lesion in the apical third and periapical lesion on tooth 21. Crown down preparation was performed and calcium hydroxide was placed for 2 weeks. An apical plug with white MTA was condensed into the resorption cavity and then the canal was obturated with gutta-percha and AH Plus sealer. The follow-up radiographs showed satisfactory resolution. CONCLUSION: This report showed the results of the treatment with MTA apical plug. The technique avoided an invasive procedure and presented some advantages, like materials biological properties and capable of sealing.