Effects of Neodymium-Doped Yttrium Aluminium Garnet (Nd:YAG) Laser Irradiation on Bone Metabolism During Tooth Movement

Abstract

IntroductionOrthodontic treatment involves moving tooth by force application and it requires a period of time. Prolonged orthodontic treatment can be a threat to oral hygiene and a source of trauma to oral tissue. Shortening the treatment time becomes one of the challenges for orthodontists. Several approaches have been described in the literature. Köle et al 1 reported that corticotomy accelerated experimental tooth movement in rats. Also Tuncay et al 2 and Young et al 3 reported that fiberotomy could achieve similar results in rats. Kanzaki et al 4 reported that local gene transfer of receptor activator of nuclear factor kappa-B ligand (RANKL) may activate osteoclast genesis and accelerate the tooth movement in periodontal tissue of rats. Also, it has been suggested that many substances such as platelet-poor plasma (PPP), platelet rich plasma (PRP), nitric oxide (NO) and prostaglandin E 2 (PGE 2 ) can accelerate experimental tooth movement. However, the side effect remains a major problem, making clinical application difficult. Chen et al 5 reported that electromagnetic wave treatment accelerated tooth movement in guinea pigs without adverse effects. Furthermore, it is shown by Nishimura et al 6 that by applying vibration, accelerated tooth movement can be achieved in beagle dogs without harm. Despite the fact that various methods have been shown to accelerate teeth movement, corticotomy is the only one applied in present. Nevertheless, the surgery represents a great burden for patients and there is also risk of tissue necrosis or infection. Therefore, a safer method is desired for orthodontic treatment. The effect of laser irradiation on orthodontic tooth movement has been attracting much attention over the past few years. Although it is indicated by numerous reports that tooth movement can be accelerated by diode laser irradiation, 7-9 there are only a few studies focused on other lasers. Ninomiya et al 10 revealed that neodymium-doped yttrium aluminium garnet (Nd:YAG) laser irradiation increased bone formation in femur metaphysis. Their results have shown the possibility of altering bone metabolism by laser irradiation. Therefore, in this experiment, The aim of this study is to evaluate the effects of low-level neodymium-doped yttrium aluminium garnet (Nd:YAG) laser irradiation on orthodontic tooth movement and histological examination. Methods: Eleven male Wistar rats (aged 10 weeks) were included. To produce experimental tooth movement in rats, 10 g force was applied to maxillary first molars with nickel titanium closed coil springs. Right molars were irradiated with Nd:YAG laser on days 0, 1, 2, 3, 7, 10, 14, 17, 21 and 24, while un-irradiated left molars were used as control. Distance between mesial side of second molar and distal side of first molar was measured on μCT image during tooth movement and the rats were sacrificed 4 weeks after the initiation of tooth movement. Results: The amount of tooth movement was significantly greater in the irradiation group (0.20 ± 0.06) than in the control group (0....

Examination of the Effect of the Combined Use of Nd: YAG Laser Irradiation and Mechanical Force Loading on Bone Metabolism Using Cultured Human Osteoblasts

“…In previous experiments, the irradiation effect of the Nd: YAG laser during orthodontic tooth movement was investigated using rats and it was proved that there was a change in bone metabolism and tooth movement. 18 In addition, in a previous study from the authors, a wound healing test was performed by irradiating osteoblast-like cells with a diode laser and confirmed that the cells proliferated. 12 There are many researches using the Nd: YAG laser in in vitro experiments, but there is no cell experiment model considering tooth movement.…”

Molecular biological and histological effects of Er:YAG laser irradiation on tooth movement

“…Fujita et al (22) indicated that the amount of tooth movement on day 7 was significantly greater in a laserirradiation group than in a non-irradiation group. Another study has also shown that the amount of tooth movement on day 7 was significantly greater in an irradiation group than in a control group (15). However, there was no difference in the amount of tooth movement on days 14, 21, and 28.…”

“…ment of teeth using Nd:YAG laser has been demonstrated so far (15). However, the degree of acceleration was very small.…”

Histological and Biochemical Investigation of the Effects of Low Intensity Pulsed Ultrasound on Orthodontic Tooth Movement

“…Administration of platelet-rich plasma (4), adiponectin (5), bisphosphonates (6), methylphenidate (7), dihydroxyvitamin D3 (8), parathyroid hormone (9), prostaglandin E2 (PGE2) (10), osteocalcin (11), icariin (12), and vitamin C (2) have been employed to increase rapidity and quality of orthodontic tooth movement. Investigators tested non-invasive techniques that are well accepted by patients including low level laser therapy (13)(14)(15) and low intensity pulsed ultrasound (16)(17)(18).…”