Reacción del tejido óseo de la rata a un sellador endodóntico a base de óxido de cinc y eugenol con acetato de hidrocortisona / Response of the bone tissue of the rat to a zin-oxide and eugenol/hydrocortisone acetate-based endodontic sealer

Objetivos: analizar comparativamente la respuesta del tejido óseo de la rat a la implantación de Kleppmethasona (KMS), un sellador endodóntico a base de óxido de cinc y eugenol que contiene un corticoide en su composición y Pulp Canal Sealer EWT (PCS), un sellador a base de óxido de cinc y eugenol convencional. Materiales y métodos: se implantaron en ambas tibias de 12 ratas, tubos de silicona obturados a ras en los dos extremos con una preparación fresca de Kleppmethasona (KMS; Klepp/Raysan SA) o Pulp Canal Sealer (PCS; Sybron-Endo) (control positivo). Como grupo negativo se utilizó la pared lateral de los tuobs de silicona (SCN). Luego de los 14 y 94 días, los implantes fueron removidos, fijados en solución de formol al 10 por ciento y procesados para su estudio histológico. Resultados: a los 14 días posimplantación, el análisis histológico reveló una reacción inflamatoria severa compuesta por polimorfonucleares neutrófilos, linfocitos, plasmocitos, macrófagos, fibroblastos y vasos de neoformación en los especímenes que se hallaban en contgacto directo con KMS y PCS. A los 94 días, en los casos en contacto con KMS, la reacción inflamatoria se redujo sustancialmente y se observó un proceso de reparación con presencia de una cápsula fibrosa sin céluals inflamatorias y el desarrollo de nuevas trabéculas óseas. En los especímenes en contacto con PCS la reacción inflamatoria inicial se redujo, pero se observó la persistencia de algunas células inflamatorias. Sin embargo, esta situación no pareció impedir el desarrollo incipiente de nuevas trabéculas óseas. En contacto con el SCN la reacción de los tejidos a los 14 días fue considerada mínima en un solo caso. Al finalizar la experiencia, los tejidos circundantes se encontraban normales en todos los casos. A los 14 días se observaron diferencias significativas (p<0,05) entre KMS/PCS y los SCN, mientras que no las hubo (p>0,05) entre ambos selladores. A los 94 día...

Physicochemical properties of endodontic sealers of different bases

OBJECTIVE: To assess the setting time (ST), flow (FL), radiopacity (RD), solubility (SB) and dimensional change following setting (DC) of different sealers (AH Plus®, Polifil, Apexit Plus®, Sealapex®, Endométhasone® and Endofill®) according to American National Standards Institute/American Dental Association (ANSI/ADA) Specification 57. MATERIAL AND METHODS: Five samples of each material were used for each test. For ST, cast rings were filled with sealers and tested with a Gilmore needle. For FL, the sealer was placed on a glass plate. After 180 s, another plate with 20 g and a load of 100 g were applied on the material, and the diameters of the discs formed were measured. In RD, circular molds were filled with the sealers, radiographed and analyzed using Digora software. For SB, circular molds were filled with the sealers, a nylon thread was placed inside the material and another glass plate was positioned on the set, pressed and stored at 37°C. Samples were weighed, placed in water, dried and reweighed. The water used for SB was analyzed by atomic absorption spectrometry. For DC, circular molds were filled with the sealers, covered by glass plates and stored at 37°C. Samples were measured and stored in water for 30 days. After this period, they were dryed and measured again. RESULTS: Regarding ST, AH Plus®, Apexit® and Endofil® sealers are in accordance with ANSI/ADA standards. Endométhasone's manufacturer did not mention the ST; Polifil is an experimental sealer and Sealapex® did not set. Considering RD, SB and DC, all sealers were in accordance with ANSI/ADA. The spectrometric analysis showed that a significant amount of K+ and Zn2+ ions was released from Apexit Plus® and Endofill®, respectively. CONCLUSION: Except for DC, all other physicochemical properties of the tested sealers conformed to ANSI/ADA requirements.

Radiographic analysis of root canal fillings: influence of two sealers on the perception of voids

The aim of this ex vivo was to investigate if two radiopaque root canal sealers with different formulations would influence the radiographic perception of root canal fillings. The root canals of 48 extracted maxillary canines were prepared and randomly assigned to 3 groups of 16 specimens each. In each group, the root canals were filled by lateral condensation of gutta-percha and one of the tested sealers: Endométhasone, Sealer 26, or a non-radiopaque sealer. A through-and-through void was simulated in half of the specimens from each group (n=8). The buccolingual radiographic images obtained were randomly interpreted for voids existence by a radiologist and an endodontist. The differences in sensitivity and specificity between groups and examiners were compared using, respectively, Fisher's Exact and McNemar tests at 5 percent significance level. Both radiopaque sealers caused a significant decrease in sensitivity at the coronal part of fillings. The use of Endométhasone increased specificity values for both coronal and apical portions of the root canal fillings. In conclusion, the tested sealers influenced the radiographic perceptions of laterally condensed root canal fillings in a different way.

O propósito deste estudo ex vivo foi investigar se dois cimentos obturadores de fórmulas diferentes influenciariam a percepção radiográfica de obturações de canais radiculares. Os canais radiculares de 48 caninos superiores extraídos foram preparados e divididos em 3 grupos. Em cada grupo os canais foram preenchidos através da condensação lateral da guta-percha e de um dos cimentos testados (Endométhasone, Sealer 26 e cimento não-radiopaco), e um defeito de ponta a ponta foi simulado em metade dos espécimes de cada grupo (n=8). As imagens radiográficas vestíbulo-linguais obtidas foram aleatoriamente interpretadas quanto à existência de defeitos por um radiologista e um endodontista. As diferenças em sensibilidade e especificidade entre os grupos e examinadores foram comparadas respectivamente usando-se os testes Exato de Fisher e McNemar ajustados ao nível de significância de 5 por cento. Ambos os cimentos radiopacos ocasionaram uma redução significativa da sensibilidade na parte cervical das obturações. O uso do Endométhasone aumentou os valores de especificidade para as porções cervical e apical das obturações dos canais radiculares. Concluiu-se que os cimentos testados influenciaram de maneira distinta a percepção radiográfica de obturações endodônticas executadas com condensação lateral.

Selective analytical determination of cinchocaine hydrochloride in presence of its degradation products or in its binary mixture with hydrocortisone

Cinchocaine HCI was degraded by refluxing with 2N HCI for 4 hr. The degradation products were isolated and their structures were confirmed by IR and mass spectrophotometry. Cinchocaine HCI was then determined in presence of its degradation products by spectrophotometric and spectro-densitometric techniques. For the spectrophotometric methods, cinchocai ne HCI was determined by first derivative spectrophotometry [Dl] at 333.6 nm or by first derivative ratio spectrophotometry [DDI] at 301.6 or 332 nm in concentration ranges 5-80 microg/ml. For the spectro-densitometric method, silica gel plates were used together with benzene: acetone: methanol: 25% NH3 [5:3:0.5:0.1, v/v] as developing solvent and the Rf values were 0.55, 0.12 and zero for cinchocaine HCI and its degradation products, respectively. Cinchocainc HCI and hydrocortisone binary mixture can be determined by the aforementioned densitometric method in concentration ranges 2-20 microg/spot and 2-16 microg/spot for cinchocaine HCI and hydrocortisone, respectively. Alternatively, cinchocaine HCI can be determined spectrophotometrically at 327.8 nm without any interference from hydrocortisone, while hydrocortisone was determined by third derivative spectrophotometry [D3] at 254 and 275.8 nm in concentration ranges 10-100 microg/ml and 5-35 microg/ml for cinchocaine HCI and hydrocortisone, respectively. The proposed methods were successfully applied for the analysis of laboratory prepared mixtures containing cinchocaine HCI and different percentages of its degradation products or cinchocaine HCI and hydrocortisone. These methods were also applied for the analysis of pharmaceutical dosage forms and the results obtained were assessed by the standard addition technique. Local anesthetics produce anesthesia by blocking sodium channels in the axonal membrane, reducing sodium conductance; this in turn reduces the rate and degree of depolarization of the nerve cell and prevents propagation of the action potential.[1] The local anesthetics should be soluble in water and should be effective when injected into tissue or when applied topically to mucous membranesi[2]. Local anesthetics are available as gel, ointments, creams and spray to provide reversible block of conduction along cutaneous nerves[3]. Cinchocaine HCI is a local anesthetic that was formerly used as nerve block and spinal anesthesia, but now, it is available only in topical form[4]. Hydrocortisone is a famous anti-inflammatory agent and it is incorporated with cinchocaine HCI in pharmaceutical preparation for treatment of haemorrhoid[3] Several methods have been described for the determination of cinchocaine HCI. These include spectrophotometric methods [5-15], fluorimetric methods [16-18] HPLC [19-22], TLC [23-27], GC [28-29] NMR [30-31] polarographic methods [32-33] and titrimetric methods [34-37] This work describes spectro-densitometric and spectrophotometric methods for the selective determination of cinchocaine HCI in presence of its two acid degradation products or in combination with hydrocortisone