Influence of photobiomodulation therapy on root development of rat molars with open apex and pulp necrosis

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.

Effect of Biostimulation on Response of Immature Teeth with Necrotic Pulp and Apical Periodontitis to Regenerative Endodontic Therapy in Immature Dogs Teeth

“…The effect of LLLT on pulp regeneration was heavily searched in literature; nevertheless, they mostly have been in vitro preclinical studies. The histologic evaluation of regenerated tissue was only revealed in three in vivo studies using rats as the animal model (49)(50)(51) . To the best available knowledge, the present study is the only one to reveal the effect of LLLT on RET using radiographic and histological both evaluation on the animal model of beagles.…”

Current Applications and Future Directions of Lasers in Endodontics: A Narrative Review

“…Trauma and decay can cause necrosis of the pulp tissue, which can lead to the obstruction of normal root development and an open apex [ 109 ]. MTA is most commonly used in order to induce an apical barrier, which is considered to be the gold standard for the treatment of teeth with an open apex and pulp necrosis [ 110 ]. Research has demonstrated that the combination of the GaAlAs diode (810 nm) laser and MTA can accelerate dentinogenesis and apexogenesis of teeth in rats and dogs, thus speeding up treatment [ 109 , 110 , 111 , 112 ].…”

“…MTA is most commonly used in order to induce an apical barrier, which is considered to be the gold standard for the treatment of teeth with an open apex and pulp necrosis [ 110 ]. Research has demonstrated that the combination of the GaAlAs diode (810 nm) laser and MTA can accelerate dentinogenesis and apexogenesis of teeth in rats and dogs, thus speeding up treatment [ 109 , 110 , 111 , 112 ]. In the study by Bahman et al [ 111 ] three healthy 4–6-month-old dogs with similar living conditions were selected, and 36 teeth involved in this in vivo study were divided into two groups, calcium hydroxide with GaAlAs diode laser (470 mW/cm 2 , 59 J/cm 2 ) irradiation and calcium hydroxide without laser irradiation, respectively.…”

Regenerative endodontics: repair or true regeneration? A narrative review

“…e available body of evidence suggests the feasibility and e ectiveness of orthotopic animal models where larger animal models, such as dogs [6][7][8][9], are preferred over smaller ones like rats [10][11][12]. Dogs still represent a more reproducible and meaningful insight as their teeth pose high similarity to human anatomy [13,14].…”