ABSTRACT
Abstract This study aimed to evaluate the role of photobiomodulation (PBM) in apexification and apexogenesis of necrotic rat molars with an open apex. Rat molars were exposed to the oral environment for 3 weeks. Canals were rinsed with 2.5% NaOCl and 17% EDTA, filled with antibiotic paste and sealed. After 7 days, canals were rinsed and divided into six groups (n=6): mineral trioxide aggregate (MTA); blood clot (BC); human dental pulp stem cells (hDPSC); MTA+PBM; BC+PBM; and hDPSC+PBM. In hDPSC groups, a 1% agarose gel scaffold was used. Two groups were not exposed: healthy tooth+PBM (n = 6), healthy tooth (n = 3); and one was exposed throughout the experiment: necrotic tooth (n = 3). In PBM groups, irradiation was performed with aluminum gallium indium phosphide (InGaAlP) diode laser for 30 days within 24-h intervals. After that, the specimens were processed for histological and immunohistochemical analyses. Necrotic tooth showed greater neutrophil infiltrate (p < 0.05). Necrotic tooth, healthy tooth, and healthy tooth+PBM groups showed absence of a thin layer of fibrous condensation in the periapical area. All the other groups stimulated the formation of a thicker layer of fibers (p < 0.05). All groups formed more mineralized tissue than necrotic tooth (p < 0.05). PBM associated with MTA, BC, or hDPSC formed more mineralized tissue (p < 0.05). MTA+PBM induced apexification (p < 0.05). Rabbit polyclonal anti-bone sialoprotein (BSP) antibody confirmed the histological findings of mineralized tissue formation, and hDPSC groups exhibited higher percentage of BSP-positive cells. It can be concluded that PBM improved apexification and favored apexogenesis in necrotic rat molars with an open apex.
Subject(s)
Animals , Tooth Diseases/radiotherapy , Dental Pulp Necrosis/radiotherapy , Tooth Apex/radiation effects , Low-Level Light Therapy/methods , Dental Pulp Cavity/radiation effects , Lasers, Semiconductor/therapeutic use , Apexification/methods , Oxides/therapeutic use , Stem Cells , Tooth Diseases/pathology , Immunohistochemistry , Random Allocation , Reproducibility of Results , Treatment Outcome , Rats, Wistar , Silicates/therapeutic use , Calcium Compounds/therapeutic use , Aluminum Compounds/therapeutic use , Dental Pulp Necrosis/pathology , Tooth Apex/pathology , Dental Pulp/cytology , Dental Pulp Cavity/pathology , Drug Combinations , Integrin-Binding Sialoprotein/analysisABSTRACT
El efecto bioestimulante de la radiación láser de baja potencia en el tejido óseo, se ha comprobado en cultivos de células y animales de experimentación. El objetivo de esta investigación fue evaluar dicho efecto en la reparación ósea periapical. Se atendieron 40 pacientes que presentaban procesos periapicales crónicos, a los que se les realizó tratamiento pulpo radicular y láser. Para la terapia láser, se útilizó la técnica puntual en el área lesionada y laserpuntura, con depósitos energéticos de 15 J/cm2 y 7 J/cm2, respectivamente. Los resultados obtenidos demuestran que existió aceleración en los procesos de reparación ósea periapical al utilizar la terapia láser, pues en el 67,5 de los pacientes atendidos, la misma ocurrió en un período menor a 6 meses después de iniciado el tratamiento