Effects of the GaAlAs diode laser (780 nm) on the periodontal tissues during orthodontic tooth movement in diabetes rats: histomorphological and immunohistochemical analysis

Abstract

The purposes of the present study are to assess the effects of the GaAlAs diode laser on the periodontal tissues and to investigate its action on the alveolar bone remodeling process during orthodontic tooth movement in normoglycemic and diabetic rats. Sixty adult male Wistar rats were divided into four groups of 15 rats: normoglycemic (N), diabetic (D), laser-normoglycemic (LN), and laser-diabetic (LD) rats. Diabetes mellitus was induced by a single intravenous injection of 40 mg/kg monohydrated alloxan. The orthodontically moved tooth underwent a force magnitude of 20 cN. The laser irradiation with a continuous emission of a 780-nm wavelength, an output power of 20 mW, and a fiber probe with a spot size of 0.04 cm in diameter and an area of 0.00126 cm were used. Moreover, an energy density of 640 J/cm was applied in an exposition time of 40 s. Histomorphological and immunohistochemical analysis was performed. The photobiomodulation (PBM) strongly stimulated the periodontal tissue response, establishing mainly the balance between the bone formation and resorption. Intense inflammatory cell infiltration and extensive loss of bone tissue were mainly found in the D group from 14 days. The number of osteopontin-positive osteocytes was significantly greater in the LN group, followed by the LD, especially at 7 and 14 days, whereas osteoprotegerin-positive osteoblasts were significantly higher in the LN and LD groups than in the N and D groups, respectively, in all periods. The PBM strongly stimulated the alveolar bone remodeling and favored the continuous reorganization of the soft periodontal tissues, leading to the maintenance and integrity of the periodontal microstructure under orthodontic force, especially in uncontrolled diabetic rats.

Periodontal Diseases in Patients with Special Health Care Needs

“…The effects of AGE accumulation increase tissue oxidant stress, alter the endothelial cell functions, elevate the activity of matrix metalloproteinases leading to the production of free radicals, and promote vascular dysfunction and cellular death. These factors may directly affect the migration and activity of inflammatory cells, impairing the mechanisms of defense against microorganisms and delaying the periodontal tissue repair processes, resulting in great losses of support structures [11].…”

“…Concerning the patients with SHCN associated to immune system deficiency, the PBM, also known as low-level laser therapy (LLLT), has been largely used to promote therapeutic and biostimulating effects, such as analgesia, antiinflammatory action, angiogenesis, and mitogenesis [11]. Gomes et al [11] assessed the impact of the GaAlAs diode laser on the periodontal tissues and investigated its effects on the alveolar bone remodeling process during orthodontic tooth movement in normoglycemic and diabetic rats.…”

“…High incidence of dental hypoplasia, traumatic lesion (factitious, iatrogenic, and accidental), drug-induced gingival overgrowth, dental malocclusion, and tooth missing are also evidenced [8,10]. It is important to highlight that the large dental loss of intact teeth is caused by the destruction of the collagen fibers of the periodontal ligament (PDL) and severe resorption of alveolar bone tissue from the persistent supra and subgingival and periopathogenic microbiota, recognized as periodontal disease [11]. Therefore, this disease is one of the most common oral chronic infections in people with special health care needs (SHCN), becoming an important dental public health problem.…”

Effects of the photobiomodulation using different energy densities on the periodontal tissues under orthodontic force in rats with type 2 diabetes mellitus

“…This apparatus was fixed over the mandibular central incisor surface with lightcured composite resin (Quick Cure, Reliance Orthodontic Products, Itasca, USA). 17 Photobiomodulation A GaAlAs diode laser (Twin Flex II, MMOptics, São Paulo, Brazil) with a continuous emission of a 780 nm wavelength, an output power of 20 mW, and a fiber probe with a spot size of 0.04 cm in diameter and an area of 0.00126 cm 2 were used. Without movement, the tip was held perpendicular and in contact with the alveolar mucosa.…”

“…In particular, the photobiomodulation (PBM), previously known as low-level laser therapy (LLLT), has showed great effectiveness due to its analgesic, anti-inflammatory and photobiostimulatory properties, resulting in a faster tooth movement with no periodontal tissue side effects. 9,10,11,12,13,14,15,16,17 However, one of the key issues is to find an appropriate energy density for different experimental and clinical trials.…”