Effect of dental adhesives on the exudative phase of the inflammatory process in subcutaneous tissue of rats

Abstract

ABSTRACT:The vascular changes in the subcutaneous connective tissue of rats induced by dentin bonding systems (one step) was studied and compared to those induced by saline solution (negative control) and Furacin (positive control), during the exudative phase of the inflammatory process. Twenty mg/kg of Evan's blue were injected intravenously in the vein of the rats' penises; 0.1 ml of each substance tested was inoculated in the subcutaneous tissue. After a 3 hour period the animals were sacrificed and their skins were excised and punched out with a standard steel 2.5 cm in diameter. The specimens were immediately immersed in 8 ml of formamide and taken to a double boiler for 72 hours at 37ºC, to remove the dye. The liquid containing the overflowed dye was filtered, analyzed in the spectrophotometer (620 nm) and classified according to the criteria established by Nagem-Filho, Pereira (1976). After statistical analysis, the irritative potential of the substances was ranked as follows: Furacin (severe) > Single Bond and Bond 1 (moderate -no significant differences between the dentin bonding systems tested) > saline solution (not significant as regards the irritation degree). DESCRIPTORS: Dentin-bonding agents; Capillary permeability. RESUMO:Estudaram-se as alterações vasculares do tecido conjuntivo subcutâneo de ratos induzidas por sistemas adesivos dentinários (único passo), comparados com solução fisiológica (controle negativo) e Furacin (controle positivo), durante a fase exsudativa do processo inflamatório. Com esse propósito, injetaram-se intravenosamente, na veia do pênis de ratos, 20 mg/kg de peso corporal de "Evan's blue", e no tecido subcutâneo inoculou-se 0,1 ml de cada substância a ser analisada. Após intervalo de três horas os animais foram sacrificados, suas peles excisadas e recortadas com perfurador de 2,5 cm de diâmetro. As peças foram imersas imediatamente em oito ml de formamida e levadas ao banho-maria a 37ºC, por 72 horas, para remoção do corante. O líquido contendo o corante extravasado foi filtrado, analisado no espectrofotômetro (620 nm) e classificado segundo os critérios estabelecidos por Nagem-Filho, Pereira (1976). O potencial irritativo dos produtos, após análise estatística, se apresentou em ordem decrescente: Furacin (considerado como grau de magnitude severo) > Single Bond e Bond 1 (que se mostraram significamente similares, classificados como moderados) > soro fisiológico (comportando-se como não-significante quanto ao grau de irritação).

Preliminary study of the inflammatory response to subcutaneous implantation of three root canal sealers

“…This method analyses the plasmatic exudate produced after an increase in vascular permeability that can be assessed by spectrophotometric measurement of the amount of extracted Evans blue dye (Rutberg et al. 1977, Nagem‐Filho et al. 2003, da Silva et al.…”

Biocompatibility of orthodontic adhesives in rat subcutaneous tissue

“…Studies 15 , 21 , 29 have demonstrated the cytotoxicity of the compounds of adhesive systems, which can be explained by the different compositions, mechanisms, and application procedures as well as by methodological variations 1 . However, it is clear that the choice for a given adhesive system should be based on its biocompatibility.…”

Effect on vascular permeability of a self-etching adhesive system containing an antimicrobial quaternary ammonium polymer QAMP into subcutaneous tissue of rats

“…In spite of observation time can vary a lot in literature, 12 most of the articles reported observation times of 3, 6 or 9 h to measure the exudative phase of the inflammatory process for different formulations (liquid and solid) of tested materials (endodontic irrigants, dental adhesives, intracanal medications, and root canal sealers). 12,13,35,38 In that sense, the observation time depends on the viscosity of tested material and its reactivity with the biological tissue. Considering these parameters, the observation times were set at 3 and 6 h since the dental adhesives were injected as liquid and only after that they were light-cured into the subcutaneous tissue of rats.…”

“…[9][10][11][12] As a simple, low cost and easy handling approach, subcutaneous implantation/ inoculation model using rats has been successfully performed in previous studies to evaluate the biocompatibility and vascular permeability of a variety of endodontic drugs, prosthetic materials, topical anaesthetics and dental adhesives. [12][13][14][15][16] In particular, vascular permeability studies can provide supporting data concerning the exudative phase of inflammatory process when phlogistic agents as novel dental materials are in contact with the connective tissue of rats. These investigations are crucial to have a better understanding of their behaviour since they tend to get an intimate contact with the pulp-dentine complex.…”