Calcium hydroxide root canal sealers - Histopathologic evaluation of apical and periapical repair after endodontic treatment

Eighty root canals of the premolars of 4 dogs, with vital pulp, were instrumented and filled during the same session with the Sealapex, CRCS, Sealer 26, and Apexit sealers, the animals were sacrificed 180 days after root canal filling and their maxillae and mandibles were removed and fixed in 10% formalin, After routine histologic processing, the sections were stained with hematoxylin-eosin and Mallory trichrome, Histopathologic analysis showed that Sealapex was the sealer that best permitted the deposition of mineralized tissue at the apical level and was the only sealer that provided complete sealing (37.5% of cases), With the use of Sealapex, no inflammatory infiltrate occurred and there was no reabsorption of mineralized tissues, In contrast, partial sealing and a moderate inflammatory infiltrate occurred with the use of CRCS, When Apexit and Sealer 26 were used the absence of sealing was frequent and active reabsorption of mineralized tissues occurred in most cases, the inflammatory infiltrate predominating with the use of Apexit was of the severe type, whereas with the use of Sealer 26 the inflammatory infiltrate was mild or absent.

Cyclosporin A-induced new cementum formation: a morphometric evaluation in the periapical region of rats

Cyclosporin A (CsA) is a potent immunosuppressor used in organ transplantation and in the management of various autoimmune diseases. Recent studies have shown that CsA stimulates deposition of cementum on root surfaces. The aim of this study was to evaluate the periapical cementum thickness and the apical foramen width in CsA-treated rats. Rats weighing 50 g were treated with a daily injection of 10 mg/kg body weight of CsA in the chow for 60 days. The cementum of the mandibular 1st molars was histologically and morphometricaly examined by analysis of 5-microm-thick serial buccolingual paraffin sections stained with hematoxylin and eosin. Histometric and stereologic analyses revealed the presence of large amounts of cementum in all root surfaces, particularly abundant in the periapical region and obliterating the foramen. The volume density of cementoblasts did not increase. Five to 90 days after the termination of CsA therapy, there was no reduction of cementum thickness. These results suggest that cementum deposition is not reversible after cessation of CsA treatment.

Diabetes triggers the loss of tooth structure associated to radiographical and histological dental changes and its evolution to progressive pulp and periapical lesions in rats

The aim of this study was to evaluate the putative influence of diabetes without metabolic control in the loss of tooth structure as well as histological changes in dentin and pulp tissue in rats. Diabetes was induced in Wistar rats (n=25) by intravenous administration of alloxan (42mg/kg). Diabetic and non-diabetic control rats were evaluated at 1, 3, 6, 9 and 12 months of follow-up. In order to evaluate the presence and progression of dental caries and periapical lesions, hemimandibles were removed and submitted to radiographical, histological, and morphometrical procedures. Dental caries were detected after radiographical and histological evaluations in diabetic group from the third month of diabetes onset, increasing gradually in frequency and severity in periods. Diabetic rats dental pulps also presented significant reduction in volume density of collagen fibers and fibroblasts at third month, parallel with a trend towards the increase in inflammatory cells volume density. Diabetic rats presented a generalized pulp tissue necrosis after 6 months of diabetes induction. Moreover, periapical lesions were not detected in control group, while these lesions were observed in all rats after 3, 6, 9, and 12 months of diabetes induction. Uncontrolled diabetes seems to trigger the loss of tooth structure, associated to histological dental changes and mediates its evolution to progressive severe pulp and periapical lesions in rats. Therefore, diabetes may be considered a very important risk factor regarding alterations in dental pulp, development of dental caries, and periapical lesions.

Periapical lesions decrease insulin signaling in rat skeletal muscle

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Determination of the p-monochlorophenol residue in the calcium hydroxide plus p-monochlorophenol combination used as an intracanal dressing in pulpless teeth of dogs with induced chronic periapical lesion

To determine the presence of p-monochlorophenol in the calcium hydroxide (Calen) + p-monochlorophenol combination after its use as intracanal dressing, periapical lesions were induced in 60 root canals of upper and lower premolars of four dogs, After biomechanical preparation, the root canals received the intracanal medication, which was removed from the apical third after 2, 4, 7, and 14 days for chemical analysis by spectrophotometry, the results showed a p-monochlorophenol loss of approximately 50.0% in the dressing after 48 h, with no further significant loss after longer periods of times, p-Monochlorophenol was still present in the medication after 14 days.

Displasia cementária periapical: considerações sobre conduta e relato de caso

A displasia cementária periapical (DCP) consiste em uma lesão óssea não neoplásica geralmente assintomática, sendo detectada em exame radiográfico de rotina. Em seu primeiro estágio apresenta-se radigraficamente semelhante a uma lesão periapical inflamatória, todavia na DCP os dentes encontram-se vitais. Neste relato de caso foi realizado o acompanhamento por sete meses de uma paciente negra com 37 anos de idade afetada por DCP no periápice de incisivos, caninos e pré-molares inferiores bilateralmente. Ao exame radiográfico foi possível notar que a lesão apresentou-se em dois estágios: osteolítico e de maturação. Os dentes reagiram positivamente aos testes de vitalidade/sensibilidade pulpar descartando, com auxílio do exame de imagem, diversas hipóteses diagnósticas do grupo das periapicopatias crônicas, contribuindo assim para uma adequada escolha do tratamento, evitando iatrogenias.

Raloxifene modulates regulators of osteoclastogenesis and angiogenesis in an oestrogen deficiency periapical lesion model

Aim To analyse the local regulatory mechanisms of osteoclastogenesis and angiogenesis during the progression of periapical lesions in female rats with oestrogen deficiency and treatment with raloxifene (RLX). Methodology Female Wistar rats were distributed into groups: SHAM-veh, subjected to sham surgery and treated with a vehicle; OVX-veh, subjected to ovary removal and treated with a vehicle; and OVX-RLX, subjected to ovary removal and treated with RLX. Vehicle or RLX was administered orally for 90 days. During treatment, the dental pulp of mandibular first molars was exposed to the oral environment for induction of periapical lesions, which were analysed after 7 and 30 days. After the experimental periods, blood samples were collected for measurement of oestradiol, calcium, phosphorus and alkaline phosphatase. The rats were euthanized and the mandibles removed and processed for immunohistochemical detection of receptor activator of nuclear factor kappa-B ligand (RANKL), osteoprotegerin (OPG), hypoxia-inducible factor-1 alpha (HIF-1α) and bone-specific alkaline phosphatase (BALP). Data were compared using Kruskal–Wallis followed by Dunn test (nonparametric values) and anova followed by the Tukey's test (parametric values). Results The plasma concentration of oestradiol showed hypo-oestrogenism in the rats subjected to ovary removal. On day 7, alkaline phosphatase activity, calcium and phosphorus were higher in the OVX-RLX group than in the OVX-veh group (P < 0.001), but immunolabelling for RANKL and HIF-1α was lower in OVX-RLX group (P < 0.001). On day 30, the OVX-veh group had higher immunolabelling for RANKL than the OVX-RLX group (P < 0.05). There were no significant differences in the immunoreactivity of OPG and BALP between any groups at either time-point (P > 0.05). Conclusion RLX therapy reversed the increased levels of the local regulators of both osteoclastogenesis and angiogenesis induced by oestrogen deficiency.

Experimentally induced anachoresis in the periapical region after root canal filling

Anachoresis is the phenomenon through which blood-borne bacteria, dyes, pigments and other materials are attracted and fixed to circumscribed areas of inflammation. This study evaluated the occurrence of anachoresis in the periapical region of dogs submitted to root canal fillings. One hundred and four roots from four dogs were endodontically treated and root canals were filled with zinc-oxide-eugenol cement. Fifty percent were filled up to the dentinocemental junction and the others were overfilled. At 120 days after root canal treatment, experimental bacteremia was induced by intravenous inoculation of 105 CFU Streptococcus pyogenes. The dogs were sacrificed 48 hours and 30 days after the bacteremia. Culture and DNA amplification by PCR revealed the presence of the inoculated bacteria just in periapical tissues of dogs sacrificed 48 hours after bacteremia and not in animals sacrificed after 30 days. AP-PCR fingerprints of recovered colonies of S. pyogenes and the presence of genetic markers of resistance to antimicrobials were similar to the inoculated strain. Endodontically treated periapices seemed to be prone to the occurrence of anachoresis and there was no relationship between the phenomenon and the level of root canal filling.

Influência da hipertensão arterial no padrão fenotípico da lesão periapical, na diferenciação dos osteoclastos, na resposta teciduale na capacidade de mineralização do cimento reparador MTA

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Monitoramento clínico do processo inflamatório periapical antes e após o uso de diferentes medicações intracanal através dos níveis de biomarcadores inflamatórios

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação histológica da próstata de cães adultos sexualmente intactos

Avaliou-se histologicamente a próstata de 30 cães adultos e idosos sexualmente intactos que apresentavam ou não sintomatologia clínica de doença prostática, e verificou-se a incidência de possíveis alterações da glândula. Dentre as alterações encontradas, a hiperplasia prostática benigna constituiu o diagnóstico mais comum, 85,6% (n=24), seguida por prostatite crônica, 64,3% (n=18), displasia do epitélio glandular, 42,8% (n=12), atrofia do epitélio glandular, 39,3% (n=11), infiltrado inflamatório focal, 25% (n=7), dilatação glandular focal, 21,4% (n=6), prostatite aguda, 7,1% (n=2), metaplasia escamosa, 3,6%, (n=1), metástase de neoplasia sistêmica, 3,6% (n=1) e abscesso prostático, 3,6% (n=1). Como em muitos casos os cães são assintomáticos, ressalta-se a importância da realização rotineira de exames clínicos específicos, como o toque retal e a ultrassonografia, para o diagnóstico precoce e o tratamento das afecções prostáticas.

Ceratomicose em equinos

O cavalo, dado o seu meio ambiente, está sujeito a afecções frequentes da córnea e da conjuntiva, tecidos oculares bastante expostos a bactérias e fungos, principalmente Aspergillus spp. e Fusarium spp. As ceratites ulcerativas bacterianas e fúngicas, bem como as ceratites fúngicas não ulcerativas, caracterizadas principalmente pelo abscesso estromal, são frequentes nessa espécie. Ocorrida a lesão inicial, perpetua-se um ciclo vicioso, com liberação de citocinas inflamatórias, que desencadeiam uma rápida e severa infiltração corneal por células polimorfonucleares. A córnea torna-se sujeita à destruição por enzimas proteolíticas liberadas pelos micro-organismos e por células inflamatórias, capazes de desencadear a dissolução estromal e a perfuração do bulbo ocular. O tratamento clínico para a resolução da doença corneal e o controle da uveíte reflexa deve ser agressivo e associado, muitas das vezes, à terapia cirúrgica. Este artigo discorre sobre a fisiopatologia e o tratamento da ceratomicose em equinos.

Experimental dermatophytosis in hamsters inoculated with Trichophyton mentagrophytes in the cheek pouch

Esse estudo apresenta os resultados obtidos quando da inoculação de Trychophyton mentagrophytes na bolsa jugal do hamster, local imunologicamente privilegiado. Foram utilizados 42 animais: 21 inoculados com 10(6) fungos na bolsa jugal (grupo 1) e, 21 inicialmente inoculados com 10(6) fungos no coxim plantar e, 15 dias após, na bolsa jugal com a mesma quantidade fúngica (grupo 2). Os animais foram sacrificados às 20 h, 3, 7, 14, 30, 60 e 120 dias; foram coletadas amostras da bolsa jugal inoculada, e das patas submetidas ao teste do coxim plantar (TCP). Independente do grupo e do tempo de evolução da infecção, os animais não desenvolveram hipersensibilidade tardia avaliada através do TCP. A pré-inoculação de fungos no coxim plantar não alterou a morfologia das lesões induzidas na bolsa jugal. Assim, nos animais do grupo 1 e grupo 2, a introdução do fungo na bolsa jugal, resultou em lesão focal, constituída por infiltrado inflamatório agudo estéril, com formação de abscesso, que evoluiu para reação macrofágica e, posteriormente, para a resolução mesmo na ausência de resposta imune detectável pelo TCP. Nossos resultados indicam que, apesar do importante papel da resposta imune na regressão espontânea da dermatofitose, outros fatores são, também, parte integral da defesa contra esta infecção fúngica.

Faringotonsilites em crianças: visão de uma amostra de pediatras e otorrinolaringologistas

As faringotonsilites agudas são infecções das vias aéreas superiores comuns na infância. OBJETIVO: Analisar opiniões e condutas de pediatras e otorrinolaringologistas do Estado de São Paulo em relação ao diagnóstico, tratamento e prevenção das faringotonsilites e suas complicações em crianças. MATERIAL E MÉTODOS: Selecionamos aleatoriamente 1370 pediatras e 1000 otorrinolaringologistas do Estado de São Paulo. Aos especialistas foi enviado questionário por correio. DESENHO do ESTUDO: Estudo transversal. RESULTADOS: 95,8% dos pediatras e 91,5% dos otorrinos não solicitam rotineiramente exames para diagnóstico laboratorial das faringotonsilites agudas na criança. Os antimicrobianos mais prescritos pelos pediatras nas faringotonsilites bacterianas foram: penicilina por via oral durante 10 dias (33,6%) e penicilina benzatina em dose única (19,7%). Os antimicrobianos mais prescritos pelos otorrinos para tratamento foram: penicilina por via oral durante 10 dias (35,4%) e penicilina por via oral durante 7 dias (25,7%). A medida de prevenção das faringotonsilites bacterianas considerada muito eficaz por mais da metade dos pediatras e otorrinos foi a cirurgia de tonsilectomia. A faringotonsilite de repetição foi o principal motivo para os otorrinos indicarem cirurgia de tonsilectomia aos escolares e adolescentes (49,3% e 53,4%, respectivamente). CONCLUSÕES: É necessário uniformizar condutas de pediatras e otorrinos para diagnóstico e tratamento das faringotonsilites em crianças.

Evaluation of genetic damage in human peripheral lymphocytes exposed to mineral trioxide aggregate and Portland cements

Mineral trioxide aggregate (MTA) and Portland cement are being used in dentistry as root-end-filling material for periapical surgery and for the sealing of communications between the root canal system and the surrounding tissues. However, genotoxicity tests for complete risk assessment of these compounds have not been conducted up to now. In the present study, the genotoxic effects of MTA and Portland cements were evaluated in peripheral lymphocytes from 10 volunteers by the alkaline single cell gel (comet) assay. The results pointed out that the single cell gel (comet) assay failed to detect the presence of DNA damage after a treatment of peripheral lymphocytes by MTA and Portland cements for concentrations up to 1000 mu g mL(-1). In summary, our results indicate that exposure to MTA or Portland cements may not be a factor that increases the level of DNA lesions in human peripheral lymphocytes as detected by single cell gel (comet) assay.