Effect of photobiomodulation on connective tissue remodeling and regeneration of skeletal muscle in elderly rats

Abstract

The purpose of this study was to evaluate the effects of low-level laser therapy (LLLT) on morphological aspects, IL-6 and IL-1β expressions, as well as the distribution and organization of collagen in the tibialis anterior (TA) muscle of elderly rats submitted to cryoinjury. Histological photomicrographs were taken of TA muscles stained with HE and picrosirius red. Immunohistochemistry was used for the evaluation of IL-6 and IL-1β. Male Wistar rats, aged 20 months, were distributed into three groups: (1) control animals not injured or treated with LLLT (n = 5), (2) cryoinjury without LLLT treatment (n = 15), and (3) cryoinjury treated with infrared LLLT (n = 15). LLLT was applied to the TA 2 h after of the injury induction and consisted of daily applications until the sacrifice (1, 3, and 7 days). The following parameters were used: λ = 780 nm, power density 1 W/cm², output power 40 mW, 10 s per point, 8 points, and 3.2 J of total energy. In the histomorphological analysis, the treated group exhibited a significant decrease in inflammatory infiltrate (p < 0.001) as well as an increase immature fibers and new blood vessels at 7 days compared to the untreated group (p < 0.05). Furthermore, treatment induced a better collagen distribution and organization at 7 days in comparison to the untreated group (p < 0.05). In conclusion, LLLT demonstrated a modulatory effect on the muscle repair process in elderly animals with regard to the collagen remodeling and morphological aspects of muscle tissue.

http://ift.tt/2ptQeZB

Er:YAG laser, piezosurgery, and surgical drill for bone decortication during orthodontic mini-implant insertion: primary stability analysis—an animal study

Abstract

It is important to identify factors that affect primary stability of orthodontic mini-implants because it determines the success of treatment. We assessed mini-implant primary stability (initial mechanical engagement with the bone) placed in pig jaws. We also assessed mini-implant insertion failure rate (mini-implant fracture, mini-implants to root contact). A total of 80 taper-shaped mini-implants (Absoanchor® Model SH1312-6; Dentos Inc., Daegu, Korea) 6 mm long with a diameter of 1.1 mm were used. Bone decortication was made before mini-implant insertion by means of three different methods: Group G1: Er:YAG laser (LiteTouch®, Light Instruments, Yokneam, Israel) at energy of 300 mJ, frequency 25 Hz, fluence 38.2 J/cm2, cooling 14 ml/min, tip 1.0 × 17 mm, distance 1 mm, time of irradiation 6 s; Group G2: drill (Hager & Meisinger GmbH, Hansemannstr, Germany); Group G3: piezosurgery (Piezotom Solo, Acteon, NJ, USA). In G4 group (control), mini-implants were driven by a self-drilling method. The primary stability of mini-implants was assessed by measuring damping characteristics between the implant and the tapping head of Periotest device (Gulden-Medizinteknik, Eschenweg, Modautal, Germany). The results in range between − 8 to + 9 allowed immediate loading. Significantly lower Periotest value was found in the control group (mean 0.59 ± 1.57, 95% CI 0.7, 2.4) as compared with Er:YAG laser (mean 4.44 ± 1.64, 95% CI 3.6, 5.3), piezosurgery (mean 17.92 ± 2.73, 95% CI 16.5, 19.3), and a drill (mean 5.91 ± 1.52, 95% CI 5.2, 6.6) (p < 0.05). The highest failure rate (33.3%) during mini-implant insertion was noted for self-drilling method (G4) as compared with G1, G2, and G3 groups (p < 0.05). The small diameter decortication by Er:YAG laser appeared to provide better primary stability as compared to drill and piezosurgery. Decortication of the cortical bone before mini-implant insertion resulted in reduced risk of implant fracture or injury of adjacent teeth. The high initial stability with a smaller diameter of the mini-implant resulted in increased risk of fracture, especially for a self-drilling method.

http://ift.tt/2IFQjm6

Photobiomodulation effect on children’s scars

Abstract

The management of burn scars has become one of the major clinical challenges in the developing countries which involve enormous treatment cost; this needs new methods for better cost benefit relationship. The objective of the study is to analyze the effectiveness of low-level laser therapy on post-burn scar tissue in children. A randomized controlled study included 15 children, ranging from 2 to 10 years of age, presenting with burn scars. They received diode laser and topical treatment. Each scar was divided into two halves. One half was treated with laser therapy and topical treatment (study area), and the other half was treated with topical treatment only (control area). The children were evaluated before and after 3 months of the study by Vancouver Scar Scale (VSS), ultrasonography (U/S), and laser Doppler perfusion imaging. Significant improvement was reported in the studied area compared to the control area for patients with P values (P = 0.005) and (P = 0.0001) for VSS and U/S scores, respectively. No difference was detected for blood perfusion to the scar between both areas (P = 0.18). In addition, no adverse effect was reported. Photobiomodulation is an efficient and safe therapeutic modality for post-burn hypertrophic scars in children and should be considered a part of combination therapy for better results.

http://ift.tt/2ptQ2tl

Comparison of the effect of root surface modification with citric acid, EDTA, and aPDT on adhesion and proliferation of human gingival fibroblasts and osteoblasts: an in vitro study

Abstract

Root demineralization is used in Periodontics as an adjuvant for mechanical treatment. The aim of this study was to evaluate the effects of root surface modification with mechanic, chemical, and photodynamic treatments on adhesion and proliferation of human gingival fibroblasts and osteoblasts. Root fragments were treated by scaling and root planing (C—control group), EDTA (pH 7), citric acid plus tetracycline (CA—pH 1), and antimicrobial photodynamic therapy (aPDT) with toluidine blue O and red laser (pH 4). Cells were seeded (104 cells/well, 6th passage) on root fragments of each experimental group and cultured for 24, 48, and 72 h. Cells were counted in scanning electron microscopy images by a calibrated examiner. For fibroblasts, the highest number of cells were present at 72-h period (p < 0.05). EDTA group showed a very low number of cells in relation to CA group (p < 0.05). CA and aPDT group presented higher number of cells in all periods, but without differences between other treatment groups (p > 0.05). For osteoblasts, there was a significant increase in cell numbers for aPDT group at 72 h (p < 0.05). In conclusion, aPDT treatment provided a positive stimulus to osteoblast growth, while for fibroblasts, aPDT and CA had a tendency for higher cell growth.

http://ift.tt/2IEzoQH

Decrease of Plasma Soluble (Pro)renin Receptor by Bariatric Surgery in Patients with Obstructive Sleep Apnea and Morbid Obesity

Metabolic Syndrome and Related Disorders, Ahead of Print.


http://ift.tt/2FZCaOV

The transition from HLA-I positive to HLA-I negative primary tumors: the road to escape from T-cell responses

Natalia Aptsiauri | Francisco Ruiz-Cabello | Federico Garrido

http://ift.tt/2u648qv

Low grade parotid mucoepidermoid carcinoma with tumour associated lymphoid proliferation (“Warthin-like”) and CRTC1-MAML2 fusion transcript: Definitive diagnosis with molecular investigation only

We report a particular type of mucoepidermoid carcinoma (MEC) of the parotid gland, with intense "tumour associated lymphoid proliferation" (TALP) which presented CRTC1-MAML2 fusion transcript.

http://ift.tt/2FOOAgb