Avaliação da influência do tabagismo no desenvolvimento da periodontite apical em ratos wistar / Evaluation of smoking influence on the development of apical periodontitis in wistar rats

A infecção endodôntica ocorre a após contaminação do tecido pulpar levando à uma colonização bacteriana dos canais radiculares resultando em uma resposta inflamatória dos tecidos periapicais e formação de uma lesão periapical, a periodontite apical (PA). O tabagismo, por sua vez, tem impactos prejudiciais à saúde oral e sistêmica sendo considerado um importante fator de risco para as doenças periodontais. Este trabalho tem por finalidade investigar a influência do tabagismo no desenvolvimento da periodontite apical em ratos. Trinta e dois ratos machos Wistar foram divididos em 4 grupos experimentais (n=8): Controle (sem periodontite apical induzida e sem inalação da fumaça do cigarro); FU (com inalação a fumaça do cigarro); PA (com periodontite apical induzida); FU+PA (com inalação a fumaça do cigarro e periodontite apical induzida). Para a inalar a fumaça do cigarro, grupo de cinco animais permaneceram em uma câmara de tabagismo inalando a fumaça de 10 cigarros por 8 minutos, três vezes ao dia, durante 50 dias. Decorridos 20 dias de inalação de fumaça do cigarro, foi realizada a cirurgia para indução da periodontite apical nos animais do grupo PA e FU+PA, no primeiro molar inferior direto, o qual permaneceu aberto na cavidade bucal por 30 dias. Nesses 30 dias subsequentes da indução da PA, os animais do grupo FU+PA e FU continuaram com a inalação a fumaça do cigarro. No 50º dia, os animais foram eutanasiados e coletados amostras de tecido hematológico para avalição dos níveis séricos de nicotina, cotinina, fosfatase alcalina, cálcio, fósforo, série vermelha e série branca. As hemimandibula removidas foram escaneadas em microtomógrafo para avaliar o volume da destruição óssea e processadas histologicamente para avaliação do perfil inflamatório e expressão das citocinas IL-6, IL-1ß, TNF-α e dos marcadores do metabolismo ósseo RANKL e OPG. Os dados foram tabulados e aplicados os testes estatísticos de Mann-Whitney para os dados não paramétricos e teste t para os dados paramétricos, a um nível de significância de P< 0.05. Com relação a análise histológica o grupo FU+PA apresentou infiltrado inflamatório mais intenso em relação aos demais grupos (P< 0,05). As citocinas pró-inflamatórias IL-6, IL-1ß, TNF-α apresentaram alto padrão de imunomarcação para o grupo FU+PA (P< 0,05). A análise histométrica mostrou maior área de reabsorção óssea no grupo FU+PA, assim como na análise microtomográfica (P< 0,05). As citocinas RANKL esteve mais expressa no grupo FU+PA (P< 0,05) e OPG teve maior expressão no grupo PA (P< 0,05). Na análise hematológica houve um aumento na concentração de hemácias, hemoglobina e leucócitos para o FU+PA (P< 0,05). Os níveis séricos de cálcio foram menores no FU+PA (P> 0,05), a fosfatase alcalina e o cálcio se manteve constante em todos os grupos experimentais (P> 0,05). A concentração sérica de nicotina e cotinina no grupo FU e FU+PA foram compatíveis com fumante humano(AU)

Endodontic infection occurs mainly after pulp tissue contamination by a carious process, leading to bacterial colonization of root canal system and inflammatory response of periapical tissues, followed by formation of apical periodontitis (AP). It is widely known that smoking has harmful impacts on oral and systemic health and is considered a risk factor for periodontal diseases. The objective of this research was to investigate the influence of smoking on the development of AP in rats. Thirty-two male Wistar rats were divided into 4 experimental groups (n = 8): C - Control (no induced AP and no cigarette smoke inhalation); CSI (cigarette smoke inhalation); AP (induced apical periodontitis); CSI + AP (cigarette smoke inhalation and induced apical periodontitis). To inhale cigarette smoke, group with five animals remained in a smoking chamber inhaling smoke from 10 cigarettes for 8 minutes, three times daily, for 50 days. After 20 days of cigarette smoke inhalation, pulp chamber access was performed to induce apical periodontitis in the first mandibular right molar, which remained with pulp chamber exposed to oral cavity for 30 days in animals in the AP and CSI + AP group. During these 30 days after the AP induction, animals in the CSI + AP and CSI group continued to inhale cigarette smoke. On the 50th day, animals were euthanized and blood sample collected to assess serum levels of nicotine, cotinine, alkaline phosphatase, calcium, phosphorus, red series and white series. The hemimandibles were removed and scanned in microtomograph to assess bone volume and histologically processed to assess inflammatory profile and expression of cytokines IL-6, IL-1ß, TNF-α and bone metabolism markers RANKL and OPG. Data were tabulated and statistically analyzed using Mann-Whitney tests for nonparametric data and analysis of variation test for parametric data, with a significance level of P< 0.05. Regarding histological analysis, CSI+AP group showed more intense inflammatory infiltrate compared to other groups (P < 0.05). Histometric analysis showed a larger area of bone resorption in the CSI + AP group, also observed in the microtomographic analysis (P< 0.05). Group CSI+AP had elevated pro-inflammatory cytokines IL-6, IL-1ß, TNF-α expression (P< 0.05). The RANKL cytokines were also more expressed in the CSI+AP group (P< 0.05), while OPG was more expressed in the AP group (P< 0.05). The hematological analysis revealed an increase in the concentration of red blood cells, hemoglobin, and leukocytes for CSI+AP (P< 0.05). Serum calcium levels were lower in CSI+AP (P> 0.05), and alkaline phosphatase and calcium remained constant in all experimental groups (P> 0.05). The serum concentrations of nicotine and cotinine in the CSI and CSI+AP group were compatible with human smokers(AU)

Accuracy of Root ZXII, E-PEX and FIND apex locators in teeth with vital pulp: an in vivo study

Abstract: This research evaluated, in vivo, the accuracy of three electronic apex locators - EALs (Root ZXII, E-PEX and FIND) in teeth with vital pulp submitted to biopulpectomy, preserving the periodontal stump. For this study, 90 single-rooted teeth with extraction indication were selected. After positive pulpal cold sensitivity test, pulp chamber access was performed. The cervical and middle thirds of root canals were instrumented with Reciproc R25, and the K#15 file was used as a standard instrument to determine working length, forming 2 groups: Constriction (insertion of the instrument until the apical constriction limit) and Foramen (insertion of the instrument until the foramen and then repositioning at constriction, without removing the file from the canal). The hand file was stabilized with a light-cured flow resin. After extraction, the samples were analyzed through microCT SkyScan 1272, with CTAN software, which evaluated the proximity between the tip of the file to the apical constriction, providing data for comparative analysis using Kruskal-Wallis and Dunn tests (p<0.05). There was a statistically significant difference in the abilities of the EALs to detect the apical constriction after reaching the foramen with Root ZX II showing higher accuracy (89%). However, there was no difference in the accuracy of the three EALs in detecting the apical constriction without reaching the foramen. Based on the present results, we conclude that EALs may show accurate measures in detecting apical constriction and foramen, even without damaging the periodontal stump in biopulpectomy.

Cleaning effectiveness of a nickel-titanium ultrasonic tip in ultrasonically activated irrigation: a SEM study

Abstract In endodontic treatment, regardless of the instrumentation technique, the presence of a smear layer covering contaminated dentin walls is always a concern. Thus, irrigation plays an essential role in reducing bacterial load. To enhance irrigation effectiveness, different ultrasonic activation methods and the use of different tips have been studied. This study assessed the cleaning capacity of the novel NiTi ultrasonic tip for smear layer removal using ultrasonically activated irrigation (UAI) with passive or continuous ultrasonic irrigation (PUI or CUI, respectively), compared with conventional irrigation. Forty-five single-rooted human mandibular premolars were decoronated to a standardized length of 16 mm. Instrumentation was performed using the Genius system up to size 50.04 and irrigated with 3% NaOCl. The specimens were divided into three groups (n = 15) according to the final irrigation activation technique: conventional irrigation (CI), as control group; PUI; and CUI, following the manufacturer's protocol. The samples were longitudinally cleaved and analyzed under a scanning electron microscope for smear layer removal according to a cleanliness score for the cervical, middle, and apical thirds. Data were evaluated by means of the Kruskal-Wallis and Tukey's tests, with a 5% level of significance. UAI enhanced cleaning compared to conventional irrigation, mainly at the apical third. CUI showed the best results, with statistically significant lower scores than PUI and CI (p < 0.05). Final irrigant activation with the NiTi tip showed better cleaning capacity than conventional irrigation. In addition, CUI resulted in better smear layer removal than PUI.

Calcium hydroxide associated with a new vehicle: Psidium cattleianum leaf extracts. Tissue response evaluation

Abstract The aim of this study was to evaluate edemogenic activity and subcutaneous inflammatory reaction induced by Psidium cattleianum leaf extracts associated with Ca(OH)2. Thirty male Wistar rats, split equally into three groups [aqueous extract + Ca(OH)2; ethanolic extract + Ca(OH)2; and propylene glycol + Ca(OH)2], were assessed every 3 h or 6 h (five animals in each period). Under general anesthesia, 0.2 mL of 1% Evans blue per 100 g of body weight was injected into the penile vein and each combination to be evaluated was subcutaneously injected into the dorsal region 30 min thereafter. Edemogenic activity was analyzed by spectrophotometry (λ=630 nm). For inflammatory reaction analysis, 50 rats received four polyethylene tubes (three experimental groups) and an empty tube (control group). The assessments were made at 7, 15, 30, 60, and 90 days, followed by hematoxylin-eosin staining and by the assignment of scores for evaluation of tissue response intensity. Ethanolic extract + Ca(OH)2 yielded the largest edemogenic activity at 3 h. Intergroup differences at 6 h were not significant. The histological analysis showed progressive repair over time (p<0.05) and aqueous and ethanolic extracts produced similar responses to those of the control and Ca(OH)2 + propylene glycol groups. Psidium cattleianum leaf extracts used as Ca(OH)2 vehicles evoked similar tissue response when compared to Ca(OH)2 associated with propylene glycol.

Mixing failures of endodontic sealers: an in vivo biocompatibility study / Falhas durante espatulação de cimentos endodônticos: um estudo de biocompatibilidade in vivo

Objectives: Evaluate, in vivo, the influence of mixing failures on endodontic sealers. Material and Methods: To alveolus analysis, 80 rats were divided into Sealapex® and AH Plus® groups. Within each group, the sealer was subjected to either partial (incomplete homogenization­ simulating handling failures) or total mixing (complete homogenization) over two periods of 7 and 30 days (n = 20). The maxillary incisor was extracted and a polyethylene tube containing the sealer was inserted. To quantify edema, 40 male rats were divided into four groups (n = 10). The animals received 2% Evans Blue intravenously, and either AH Plus® or Sealapex® was injected subcutaneously. The rats were euthanized after 3 or 6 hours and analyzed in a spectrophotometer (630 ƞm). To analyze the subcutaneous tissue, 20 rats received polyethylene tube implants with the sealers in the dorsal area (n=10), then euthanized after either 7 or 30 days, and inflammation was evaluated according to an inflammatory cells score. Results: In the alveolar 7-day group, control group presented an inflammation score 1, while all other groups presented a score 2, except AH plus® total mix group (3). After 30 days, all groups presented a score 1. The edemogenic test showed less edema in Sealapex® groups (p < 0.5). In subcutaneous 7-day period, all groups presented score 2. In 30 days, all groups revealed score 1, except AH Plus® partial mix group (2). Conclusion: Regarding mixing of the sealers, there were no significant differences among the groups (AU)

Objetivo: Avaliar, in vivo, a influência das falhas de espatulação de cimentos endodônticos. Material e Métodos: Para análise alveolar, 80 ratos foram divididos nos grupos Sealapex® e AH Plus®. Em cada grupo, o cimento foi espatulado de forma parcial (homogeneização incompleta, simulando falhas) ou total (homogeneização completa) em dois períodos de 7 e 30 dias (n=20). O incisivo superior foi extraído e um tubo de polietileno contendo o cimento foi inserido. Para quantificar edema, 40 ratos foram divididos em quatro grupos (n = 10). Os animais receberam Azul de Evans 2% intravenoso, e AH Plus® ou Sealapex® injetados no tecido subcutâneo. Após 3 ou 6 horas foram eutanasiados e analisados em espectrofotômetro (630 ƞm). Para analisar a resposta subcutânea, 20 ratos receberam implantes de tubo de polietileno com os cimentos na região dorsal (n = 10), eutanasiados após 7 ou 30 dias, e a inflamação foi avaliada de acordo com um escore de células inflamatórias. Resultados: Na análise alveolar em 7 dias, o grupo controle apresentou escore 1 de inflamação, enquanto que todos os outros grupos apresentaram 2, com exceção do AH plus® espatulação total (3). Após 30 dias, todos os grupos apresentaram escore 1. O teste edemogênico mostrou menor edema nos grupos Sealapex® (p < 0,5). No período subcutâneo de 7 dias, todos os grupos apresentaram escore 2. Em 30 dias, todos os grupos revelaram escore 1, exceto AH Plus® espatulação parcial (2). Conclusão: Não houve diferença estatística significante entre os cimentos quanto à espatulação. (AU)