Negative Pressure Irrigation Presents Mineralizing Potential in Dogs' Immature Teeth with Periapical Lesion.

The objective of this in vivo study was to assess the effect of the root canal irrigation by negative and positive apical pressure on the expression of molecules that are an indicative of cell differentiation with mineralizing phenotype in teeth of dogs with incomplete rhizogenesis and induced periapical lesion. A total of 30 teeth (60 roots) were distributed into 3 groups (n=20): EndoVac®, Conventional and Control. After 90 days, the routine histotechnical procedures were performed and the sections were submitted to immunohistochemical technique for the staining of osteopontin (OPN), alkaline phosphatase (ALP) and the RUNX2 transcription factor in the apical and periapical regions of the roots. A semi-quantitative analysis of the positive immunostaining was performed and the intensity of the expression was classified in absent (0), mild (1), moderate (2), or intense (3). Scores data were statistically analyzed by the Kruskal-Wallis non-parametric test and Dunn post-test, and the significance level was set at 5%. RUNX2 immunostaining revealed that in the negative pressure group there was a significantly stronger (p<0.05) immunostaining in comparison to the control group. Regarding the OPN expression, it was not possible to detect a statistically significant difference between the groups (p>0.05). After analyzing ALP immunostaining, a statistically significant difference was observed between the groups (p<0.05), and the negative pressure group showed a markedly stronger mark immunostaining than the control group. The results of the present in vivo study allowed concluding that negative apical pressure irrigation presents mineralizing potential in immature teeth with apical periodontitis.

Negative pressure irrigation presents mineralizing potential in dogs' immature teeth with periapical lesion

Abstract The objective of this in vivo study was to assess the effect of the root canal irrigation by negative and positive apical pressure on the expression of molecules that are an indicative of cell differentiation with mineralizing phenotype in teeth of dogs with incomplete rhizogenesis and induced periapical lesion. A total of 30 teeth (60 roots) were distributed into 3 groups (n=20): EndoVac®, Conventional and Control. After 90 days, the routine histotechnical procedures were performed and the sections were submitted to immunohistochemical technique for the staining of osteopontin (OPN), alkaline phosphatase (ALP) and the RUNX2 transcription factor in the apical and periapical regions of the roots. A semi-quantitative analysis of the positive immunostaining was performed and the intensity of the expression was classified in absent (0), mild (1), moderate (2), or intense (3). Scores data were statistically analyzed by the Kruskal-Wallis non-parametric test and Dunn post-test, and the significance level was set at 5%. RUNX2 immunostaining revealed that in the negative pressure group there was a significantly stronger (p<0.05) immunostaining in comparison to the control group. Regarding the OPN expression, it was not possible to detect a statistically significant difference between the groups (p>0.05). After analyzing ALP immunostaining, a statistically significant difference was observed between the groups (p<0.05), and the negative pressure group showed a markedly stronger mark immunostaining than the control group. The results of the present in vivo study allowed concluding that negative apical pressure irrigation presents mineralizing potential in immature teeth with apical periodontitis.

Resumo O objetivo do presente estudo in vivo foi avaliar o efeito da irrigação do canal radicular por pressão apical negativa e por pressão positiva na expressão de moléculas que são indicativas de diferenciação celular com fenótipo mineralizador em dentes de cães com rizogênese incompleta e lesão periapical. Um total de 30 dentes (60 raízes) foi distribuído em 3 grupos (n=20): EndoVac, Convencional e Controle. Após 30 dias, foram realizados os procedimentos histotécnicos de rotina e os cortes foram submetidos à técnica de imunohistoquímica para marcação de Osteopontina (OPN), Fosfatase Alcalina (ALP) e para o fator de transcrição RUNX2 nas regiões apical e periapical das raízes. Foi realizada uma análise semi-quantitativa da imunomarcação positiva e a intensidade da expressão foi classificada em ausente (0), leve (1), moderada (2) ou intensa (3). Os dados por escores foram analisados estatisticamente pelo teste não-paramétrico de Kruskal-Wallis e pelo pós-teste de Dunn, e o nível de significância adotado foi de 5%. A imunumarcação para RUNX2 revelou que no grupo pessão negativa houve marcação significativamente mais intensa (p<0,05), em comparação ao grupo controle. Com relação à expressão de OPN, não foi possível observer diferença estatisticamente significante entre os grupos (p>0,05). Após análise da imunomarcação para ALP, foi observado diferença estatisticamente significante entre os grupos (p<0,05), e o grupo pressão negativa demonstrou uma marcação siginificativamente mais intensa do que o grupo controle. Os resultados do presente estudo in vivo permitiram concluir que a irrigação por pressão apical negativa apresenta potencial mineralizador em dentes com ápice aberto e lesão periapical.