Evaluation of laser phototherapy (λ 780 nm) after dental replantation in rats.

BACKGROUND/AIM: Tooth replantation is the treatment of choice in cases of avulsion although the outcomes are variable. The teeth can be lost due to external root resorption. The aim of this study was to histologically assess of the effect of laser phototherapy (λ780 nm) on replanted teeth in rats. MATERIAL AND METHODS: Sixty Wistar Albinus rats had their maxillary right incisors extracted and were then divided into four groups: G1-absence of storage medium; G2-milk as storage medium; G3-milk as storage medium followed by a laser irradiation of the root surfaces and entrance of the alveolus (λ = 780 nm; P = 70 mW; CW; DE = 21 J/cm2 ); G4-milk as storage medium, laser irradiation as in G3 before replantation. After this procedure, laser irradiation was performed on the buccal and palatal mucosa (8.4 J/cm2 per session) every 48 h for 15 days. The animals were euthanized 15, 30, and 60 days after replantation. RESULTS: The histological results showed that after 15 days, G4 exhibited intense chronic inflammation with the presence of clastic cells and moderate external inflammatory root resorption (P < 0.05) when compared with G3, in which these outcomes were not observed. At the 30th day, G1, G2, and G4 showed chronic inflammation varying from discrete to moderate, as well as intense external inflammatory root resorption. G3 remained without any inflammation and external inflammatory root resorption up to the 60th day. CONCLUSIONS: The use of laser phototherapy on the root surface and at the entrance of the alveolus prior to replantation had a positive biomodulative effect on alveolar repair after tooth replantation in rats.

Assessment of the use of LED phototherapy on bone defects grafted with hydroxyapatite on rats with iron-deficiency anemia and nonanemic: a Raman spectroscopy analysis.

This study aimed to assess bone repair in defects grafted or not with hydroxyapatite (HA) on healthy and iron-deficiency anemia (IDA) rats submitted or not to LED phototherapy (LED-PT) by Raman spectroscopy. The animals were divided in eight groups with five rats each: Clot; Clot + LED; IDA + Clot; IDA + LED; Graft; Graft + LED; IDA + Graft; and IDA + Graft + LED. When appropriated, irradiation with IR LED (λ850 ± 10 nm, 150 mW, CW, Φ = 0.5 cm(2), 16 J/cm(2), 15 days) was carried out. Raman shifts: ∼ 960 [symmetric PO4 stretching (phosphate apatite)], ∼ 1,070 [symmetric CO3 stretching (B-type carbonate apatite)], and ∼ 1,454 cm(-1) [CH2/CH3 bending in organics (protein)] were analyzed. The mean peak values for ∼ 960, ∼ 1,070, and ∼ 1,454 cm(-1) were nonsignificantly different on healthy or anemic rats. The group IDA + Graft + LED showed the lowest mean values for the peak ∼ 960 cm(-1) when compared with the irradiated IDA group or not (p ≤ 0.001; p ≤ 0.001). The association of LED-PT and HA-graft showed lowest mean peak at ∼ 1,454 cm(-1) for the IDA rats. The results of this study indicated higher HA peaks as well as a decrease in the level of organic components on healthy animals when graft and LED phototherapy are associated. In the other hand, IDA condition interfered in the graft incorporation to the bone as LED phototherapy only improved bone repair when graft was not used.