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
The application of laser as a therapeutic measure in nervous regeneration in dentistry has not been a discussed subject, even though the knowledge about the response of the peripheral nervous system is very important inpractice as well as in the recovery of the patient. It has been proposed that low-level laser (LLL) therapy has beneficial effects on tissues; LLL therapy acts as an analgesic, anti-inflammatory, anti-edematous, anti-cellulitic tool, and it stimulates cellular trofism. In the present study, we conducted a meta-analysis of available literature regarding the response of the injured nerveto low-power laser using search engines EBSCO and PUBMED. The literature refers to the stimulant effect of the low-level laser in the neoformation of vessels and to the existing bibliographic evidence to propose that this mechanism is important in nervous regeneration. There is limited bibliographic evidence on the effects of LLL therapy in dentistry.
La aplicación de láser como medio terapéutico en la regeneración nerviosa en odontología, no ha sido un tema muy discutido, aún cuando el conocimiento de la respuesta del sistema nervioso periférico es muy importante tanto en la práctica como en la recuperación del paciente. Se ha propuesto que el láser de baja potencia (LBP) tiene efectos benéficos en los tejidos, entre ellos antiálgico, antiinflamatorio, antiedematoso, anticelulítico y bioestimulante del trofismo celular. En el presente estudio se realizó un metaanálisis de la literatura disponible en relación con la respuesta del nervio lesionado ante la aplicación de láser de baja potencia utilizando los buscadores EBSCO y PUBMED. La literatura se refiere al efecto estimulante del LBP en la neoformación de vasos y existiendo evidencia bibliográfica para proponer a este mecanismo como importante en la regeneración nerviosa. Los efectos del láser de baja potencia en Odontología presentaron una escasa evidencia bibliográfica.