Evaluation of the dentin changes in teeth subjected to endodontic treatment and photodynamic therapy
Avaliação das alterações morfológicas de dentes submetidos ao tratamento endodôntico e a terapia fotodinâmica
Lacerda, Mariane Floriano Lopes Santos; Lima, Carolina Oliveira de; Lacerda, Gabriel Pinheiro; Campos, Celso Neiva
Abstract
Introduction: Antimicrobial photodynamic therapy (PDT) is an efficient adjuvant technique to promote disinfection of the root canal system. Therefore, it is important to investigate changes to dentin morphology and permeability induced by the use of diode laser on the root dentin. Objective: The purpose of this study was to investigate morphological changes and the percentage of apical leakage after the use of laser. Material and method: Forty single‐rooted teeth were instrumented using rotary system and irrigated. Teeth were randomly divided in two groups: G1 - not exposed to PDT (control), and G2 - pretreated with toluidine blue photosensitizer and irradiated with AsGaAl laser diode. Ten teeth in each group were evaluated by SEM for morphological changes. The other ten teeth were filled and stained with Rhodamine B to evaluate the apical leakage. Result: The results showed significant difference between G1 and G2 (p <0.001 - chi-square), with greater presence of debris in G1 and higher incidence of open dentinal tubules in G2. Erosions and cracks were observed in both groups, with no statistically significant difference (p> 0.001). The apical leakage was significantly higher in G2 than in G1 (p <0.001 - Student’s t-test). Conclusion: It was concluded that the use of low-level laser reduced the smear layer and opened the dentinal tubules. Use of laser increased the permeability of the apical dentin.
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Resumo
Introdução: A PDT antimicrobiana é um eficiente método coadjuvante na desinfecção do sistema de canais radiculares, o que torna importante o estudo sobre a possibilidade de alterações morfológicas e permeabilidade provocadas pelo laser de diodo na estrutura dentinária radicular. Objetivo: A proposta deste estudo foi investigar as alterações morfológicas e percentual de infiltração apical radicular após o uso do laser diodo. Material e método: Quarenta dentes monorradiculares foram instrumentados pelo sistema rotatório Protaper e irrigados com NaOCl 5,25% e EDTA 17%. Depois, foram divididos aleatoriamente em: G1: não receberam PDT (controle); G2: receberam pré‐irradiação com fotossensibilizador azul de toluidina e irradiação com laser diodo de AsGaAl. Em seguida, 10 dentes de cada grupo foram analisados por MEV quanto as alterações morfológicas. Os outros 10 dentes foram obturados e corados por Rodamina B para avaliar o percentual de infiltração apical. Resultado: Os resultados mostraram diferença significativa entre G1 e G2 (p<0,001 - qui-quadrado), verificando maior presença de debris em G1 (controle) e maior ocorrência de túbulos dentinários abertos em G2 (PDT). Erosões e cracks foram observadas em ambos os grupos, sem diferença estatística significativa (p>0,001). O percentual de infiltração apical foi significativamente maior em G2 que em G1 (p<0,001 – t student). Conclusão: Concluiu-se que a utilização do laser diodo promoveu a redução de smear layer e abertura dos túbulos dentinários, não influenciando na ocorrência de erosão, cracks e carbonização. O laser aumentou a permeabilidade da dentina apical.
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References
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