Effect of laser therapy on the inflammatory response induced by endodontic medications implanted into the subcutaneous tissue of rats

Abstract

ResumoIntrodução: Medicamentos endodônticos apresentam componentes tóxicos que provocam algum grau de reação inflamatória. Objetivo: Este estudo avaliou o efeito da laserterapia na resposta inflamatória causada por medicações intracanais, em tecido subcutâneo de ratos, por meio da análise quantitativa de mastócitos. Material e método: Tubos de polietileno contendo as medicações foram implantados no dorso de 60 ratos, distribuídos em seis grupos: HS (pasta de hidróxido de cálcio P.A.); HL (pasta de hidróxido de cálcio P.A. e laserterapia); HPS (pasta de hidróxido de cálcio P.A. com paramonoclorofenol canforado); HPL (pasta de hidróxido de cálcio P.A. com paramonoclorofenol canforado e laserterapia); IS (iodofórmio e soro fisiológico) e IL (iodofórmio, soro fisiológico e laserterapia). Os animais foram eutanasiados oito e quinze dias após a cirurgia, as peças cirúrgicas foram removidas, processadas para inclusão em parafina e os cortes histológicos corados em Azul de Toluidina 0.2%, para quantificação dos mastócitos. A análise de variância (ANOVA) e o teste de Tukey post hoc foram aplicados para determinar diferenças significativas entre os grupos quanto ao número de mastócitos (p<0.05). Resultado: Nos grupos HL, HPL e IL houve uma diminuição de mastócitos em ambos os períodos experimentais em relação aos grupos HS, HPS e IS, porém não se observou diferença estatística significativa entre o grupo HPS e o HPL aos oito dias. Conclusão: A laserterapia foi eficaz em modular a intensidade da resposta inflamatória induzida pelos medicamentos endodônticos a partir da redução significativa na quantidade de mastócitos.Descritores: Endodontia; laserterapia; mastócitos; inflamação; subcutâneo. Abstract Introduction: Endodontic medications contain toxic components that cause varying degrees of inflammation.Objective: This study evaluated the effect of laser therapy on the inflammatory response induced by intracanal medications implanted into the subcutaneous tissue of rats using a quantitative analysis of mast cells. Material and method: Polyethylene tubes containing the medications were implanted in the dorsum of 60 rats divided into six groups, including HS (P.A. calcium hydroxide paste), HL (P.A. calcium hydroxide paste and laser therapy), HPS (P.A. calcium hydroxide paste with camphorated paramonochlorophenol), HPL (P.A. calcium hydroxide paste with camphorated paramonochlorophenol and laser therapy), IS (iodoform with saline) and IL (iodoform with saline and laser therapy). The animals were euthanized eight or fifteen days after surgery, and samples were removed and embedded in paraffin. Histological sections were stained with 0.2% toluidine blue for the quantification of mast cells. Analysis of variance (ANOVA) and Tukey's post-hoc test were applied to determine significant differences in the number of mast cells between groups (p<0.05). Result: There was a decrease in mast cells for the HL, HPL and IL groups when compared with the HS, HPS and IS groups at both time points. There was no statistically significant differe...

Laser phototherapy induces angiogenesis in the periodontal tissue after delayed tooth replantation in rats

“…Several studies have been developed for decades to investigate the effects of red and/or infrared laser lights on tissue repair ( 8 - 12 , 14 , 15 , 20 , 21 , 23 , 26 ) but only few recent works have studied their effects on the periodontal repair process of replanted teeth ( 8 - 12 ). Although some reports have shown that LPT is capable of improving the periodontal repair process of replanted teeth in vivo by reducing the occurrence of inflammatory root resorption and ankyloses ( 9 - 12 ), its effects are still inconclusive because of the lack of studies, the methodological differences mainly in LPT protocols, and the many variables that may alter the response of biological tissues ( 12 ).…”

“…When stimulated, these enzymes accelerate cellular metabolism throughout the increment of adenosine triphosphate (ATP) synthesis, providing energy for cellular activities that are essential for the processes of mitosis and protein synthesis ( 29 ). These events favor the healing process through increased cell proliferation, production of nucleic acids, formation of collagen, and reduction of inflammation ( 12 , 14 , 15 , 20 - 23 , 26 ).…”

Assessment of carvacrol paste as endodontic medication associated with laser photobiomodulation in tissue repair: an experimental study in rats

“…The interaction of laser with biological tissues depends on wavelength, energy density, and power. Among the mechanisms involved in the biological effects of LLLT, there is an increase in local microcirculation, angiogenesis, vasodilation, and inhibition of inflammatory mediators such as prostaglandins (RIBEIRO et al, 2009;MATOS et al, 2014).…”

Assessment of intracanal medications cytotoxicity on L929 fibroblast cells

“…When calcium hydroxide comes into direct contact with subcutaneous tissue, inflammation occurs (MATOS et al, 2014), inducing moderate to severe levels of protein denaturation in cells, especially neutrophils; areas of necrosis and dystrophic calcification are also observed.…”

“…However, calcium hydroxide is considered to be less cytotoxic than other medications commonly used in endodontic therapy (GUIGAND et al, 1999;SEPET et al, 2009;MIURA et al, 2010;MATOS et al, 2014).…”