Assessment of the systemic effects of low-level laser therapy (LLLT) on thyroid hormone function in a rabbit model

Fronza, Bruna Rodrigues; Somacal, T.; Mayer, Luciano; Moraes, João Feliz Duarte de; Oliveira, Marília Gerhardt de; Weber, João Batista Blessmann

doi:10.1016/j.ijom.2012.06.017

Cited by 22 publications

(24 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The main issue discussed here is the anatomical proximity between the irradiated structures of the lower face and the thyroid gland, which is the nearest hormonal secretory gland to the oral tissues. Fronza et al 38 have recently described a similar experiment after mandibular incisive extraction, using 6 J/cm 2 per session applied to the socket.…”

Section: Discussionmentioning

confidence: 99%

“…12 We assumed that LLLT applied to the lower face could lead to indirect exposure of the thyroid gland, as 830 nm wavelength lasers can reach deeper planes and exert both local and systemic effects. 5,6,[28][29][30]36,38 The rabbit model was chosen because of the previously reported ease of handling, surgical preparation, and postoperative follow-up. 8,28,34,38 Moreover, the size of these animals enabled the use of conventional implants available for clinical use in humans.…”

Section: Discussionmentioning

confidence: 99%

“…5,6,[28][29][30]36,38 The rabbit model was chosen because of the previously reported ease of handling, surgical preparation, and postoperative follow-up. 8,28,34,38 Moreover, the size of these animals enabled the use of conventional implants available for clinical use in humans. As for implant placement in fresh tooth extraction sockets, we chose this method of implant placement, rather than the tibia (which is the most common site reported in the literature), in order to provide the closest possible simulation of a clinical situation.…”

Section: Discussionmentioning

confidence: 99%

“…These procedures would not be possible in rats or mice. 9,10,13,40 In accordance with the most recent literature, LLLT was delivered by an infrared laser [7][8][9][10][11][12][13][14][15][26][27][28]35,38 of 830 nm wavelength 7,10,[12][13][14][15] and 50 mW output power in two sites near the mandibular implant, in seven sessions 7,11,12,15 every 48 h, using three different doses. The use of a sham surgery and sham LLLT control group (C-I), as well as a baseline surgery but sham LLLT group (C-II), enabled us to isolate both the influence of baseline surgery and the systemic effects of LLLT.…”

Section: Discussionmentioning

confidence: 99%

“…Using methods similar to those of Mebis et al 37 and Fronza et al, 38 levels of T3, T4, and calcium were measured in all animals at four points in time: before dental extraction/ implant placement; immediately after surgery; after the first LLLT session; and after the last LLLT session. Blood samples ( …”

Section: Methodsmentioning

confidence: 99%

See 4 more Smart Citations

Effect of Three Different Protocols of Low-Level Laser Therapy on Thyroid Hormone Production After Dental Implant Placement in an Experimental Rabbit Model

Weber

Mayer²,

Cenci³

et al. 2014

Photomedicine and Laser Surgery

View full text Add to dashboard Cite

Objective: The purpose of this study was to assess the systemic effects of low-level laser therapy (LLLT) on thyroid gland function and, consequently, calcium regulation -as measured by serum triiodothyronine (T3), thyroxine (T4), and free calcium levels -when administered after dental implant placement in a rabbit model. Background data: Protocols for the use of laser therapy in several clinical procedures are currently under investigation, as not all of the actions and systemic effects of laser irradiation have been clearly established. Materials and methods: Forty male adult New Zealand rabbits were distributed across five groups of eight animals each: two control groups (C-I and C-II) of unirradiated animals, and three experimental groups (E-5, E-10, and E-20), each exposed to a distinct dose of gallium-aluminum-arsenide (GaAlAs) laser [k = 830 nm, 50 mW, continuous wave (CW)] every 48 h for a total of seven sessions. The total dose per session was 5 J/cm 2 in E-5, 10 J/cm 2 in E-10, and 20 J/cm 2 in E-20. Animals in C-II and all experimental groups underwent surgical extraction of the mandibular left incisor followed by immediate placement of an osseointegrated implant (Nanotite Ò , Biomet 3i TM ) into the socket. Animals in group C-I served as an absolute control for T3, T4, and calcium measurements. The level of significance was set at 5% ( p £ 0.05). Results: ANOVA with Tukey's posthoc test revealed significant differences in T3 and calcium levels among experimental groups, as well as significant within-group differences in T3, T4, and calcium levels over time. Conclusions: Although not reaching abnormal values, LLLT applied to the mandible influenced thyroid function in this model.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Effect of Three Different Protocols of Low-Level Laser Therapy on Thyroid Hormone Production After Dental Implant Placement in an Experimental Rabbit Model

Weber

Mayer²,

Cenci³

et al. 2014

Photomedicine and Laser Surgery

View full text Add to dashboard Cite

show abstract

Resistance exercise and low‐level laser therapy improves grip strength and morphological aspects in the ankle joint of Wistar rats with experimental arthritis

Retameiro¹,

Neves²,

Tavares³

et al. 2022

The Anatomical Record

View full text Add to dashboard Cite

Rheumatoid arthritis (RA) is an inflammatory disease mainly affecting synovial joints. Photobiomodulation through low‐level laser therapy (LLLT) and resistance exercise may improve the inflammatory process. Therefore, we analyzed the effects of resistance exercise, LLLT, and the combination of both treatments on hind paw grip strength and ankle joint histomorphometric aspects of Wistar rats subjected to experimental RA. A total of 64 male Wistar rats were divided into eight groups: control, control LLLT, control exercise, control LLLT and exercise, arthritis, arthritis LLLT, arthritis exercise, and arthritis LLLT and exercise groups. The experimental RA was induced by a complete Freund's adjuvant injection into the knee joint cavity. Climbing exercises and LLLT (660 nm; 5 J/cm2 per point) were performed as the treatment. In addition, muscle strength was evaluated using the grip strength test, and morphometric evaluations were performed on the ankle joint. Generalized mixed models and multivariate analysis of variance tests were used for statistical analysis. Statistical significance was set at a p‐value of .05. Arthritis LLLT, exercise, and LLLT and exercise had positive effects on grip strength between the groups (F[7.56] = 5.8, p < .004) and within the groups (F[4.3] = 9.9, p < .002) throughout the evaluations. Morphometry revealed degenerative lesions in the ankle joint as subintima with angiogenesis, inflammatory cells, flocculated articular cartilage, chondrocyte disorganization, and pannus in the arthritis group (p < .001). The treated groups exhibited morphological characteristics similar to those of the control group. LLLT and resistance exercise restored muscle strength and morphological aspects of the ankle joint in rats with experimentally induced RA.

show abstract

Peri-implant osseointegration after low-level laser therapy: micro-computed tomography and resonance frequency analysis in an animal model

et al. 2016

View full text Add to dashboard Cite

The purpose of the present study is to evaluate the effects of low-level laser therapy on the osseointegration process by comparing resonance frequency analysis measurements performed at implant placement and after 30 days and micro-computed tomography images in irradiated vs nonirradiated rabbits. Fourteen male New Zealand rabbits were randomly divided into two groups of seven animals each, one control group (nonirradiated animals) and one experimental group that received low-level laser therapy (Thera Lase®, aluminum-gallium-arsenide laser diode, 10 J per spot, two spots per session, seven sessions, 830 nm, 50 mW, CW, Ø 0.0028 cm). The mandibular left incisor was surgically extracted in all animals, and one osseointegrated implant was placed immediately afterward (3.25ø × 11.5 mm; NanoTite, BIOMET 3i). Resonance frequency analysis was performed with the Osstell® device at implant placement and at 30 days (immediately before euthanasia). Micro-computed tomography analyses were then conducted using a high-resolution scanner (SkyScan 1172 X-ray Micro-CT) to evaluate the amount of newly formed bone around the implants. Irradiated animals showed significantly higher implant stability quotients at 30 days (64.286 ± 1.596; 95 % confidence interval (CI) 60.808-67.764) than controls (56.357 ± 1.596; 95 %CI 52.879-59.835) (P = .000). The percentage of newly formed bone around the implants was also significantly higher in irradiated animals (75.523 ± 8.510; 95 %CI 61.893-89.155) than in controls (55.012 ± 19.840; 95 %CI 41.380-68.643) (P = .027). Laser therapy, based on the irradiation protocol used in this study, was able to provide greater implant stability and increase the volume of peri-implant newly formed bone, indicating that laser irradiation effected an improvement in the osseointegration process.

show abstract

Assessment of the systemic effects of low-level laser therapy (LLLT) on thyroid hormone function in a rabbit model

Cited by 22 publications

References 27 publications

Effect of Three Different Protocols of Low-Level Laser Therapy on Thyroid Hormone Production After Dental Implant Placement in an Experimental Rabbit Model

Effect of Three Different Protocols of Low-Level Laser Therapy on Thyroid Hormone Production After Dental Implant Placement in an Experimental Rabbit Model

Resistance exercise and low‐level laser therapy improves grip strength and morphological aspects in the ankle joint of Wistar rats with experimental arthritis

Peri-implant osseointegration after low-level laser therapy: micro-computed tomography and resonance frequency analysis in an animal model

Contact Info

Product

Resources

About