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Orthodontic treatment involves the use of apparatuses that impairs oral hygiene making patients susceptible to periodontal diseases and caries. To prevent increased antimicrobial resistance A-PDT has shown itself a feasible option. The aim of this investigation was to assess the efficiency of A-PDT employing 1,9-Dimethyl-Methylene Blue zinc chloride double salt - DMMB as a photosensitizing agent combined with red LED irradiation (λ640 ± 5 ηm) against oral biofilm of patients undertaking orthodontic treatment. Twenty-one patients agreed to participate. Four biofilm collections were carried out on brackets and gingiva around inferior central incisors; first was carried out before any treatment (Control); second followed five minutes of pre-irradiation, the third was immediately after the first AmPDT, and the last after a second AmPDT. Then, a microbiological routine for microorganism growth was carried out and, after 24-h, CFU counting was performed. There was significant difference between all groups. No significant difference was seen between Control and Photosensitizer and AmpDT1 and AmPDT2 groups. Significant differences were observed between Control and AmPDT1 and AmPDT2 groups, Photosensitizer and AmPDT1 and AmPDT2 groups. It was concluded that double AmPDT using DMBB in nano concentration and red LED was capable to meaningfully decrease the number of CFUs in orthodontic patients., Competing Interests: Declaration of Competing Interest None, (Copyright © 2023 Elsevier B.V. All rights reserved.)

The repair of large bone defects is lengthy and complex. Both biomaterials and phototherapy have been used to improve bone repair. We aimed to describe histologically the repair of tibial fractures treated by wiring (W), irradiated or not, with laser (λ780 nm, 70 mW, CW, spot area of 0.5 cm 2 , 20.4 J/cm 2 (4 × 5.1 J/cm 2 , Twin Flex Evolution®, MM Optics, Sao Carlos, SP, Brazil) per session, 300 s, 142.8 J/cm 2 per treatment) or LED (λ850 ± 10 nm, 150 mW, spot area of 0.5 cm 2 , 20.4 J/cm 2 per session, 64 s, 142.8 J/cm 2 per treatment, Fisioled® , MM Optics, Sao Carlos, Sao Paulo, Brazil) and associated or not to the use of mineral trioxide aggregate (MTA, Angelus®, Londrina, PR, Brazil). Inflammation was discrete on groups W and W + LEDPT and absent on the others. Phototherapy protocols started immediately before suturing and repeated at every other day for 15 days. Collagen deposition intense on groups W + LEDPT, W + BIO-MTA + LaserPT and W + BIO-MTA + LEDPT and discrete or moderate on the other groups. Reabsorption was discrete on groups W and W + LEDPT and absent on the other groups. Neoformation varied greatly between groups. Most groups were partial and moderately filed with new-formed bone (W, W + LaserPT, W + LEDPT, W + BIO-MTA + LEDPT). On groups W + BIO-MTA and W + BIO-MTA + LaserPT bone, neoformation was intense and complete. Our results are indicative that the association of MTA and PBMT (λ = 780 nm) improves the repair of complete tibial fracture treated with wire osteosynthesis in a rodent model more efficiently than LED (λ = 850 ± 10 nm).

This study aimed to assess the repair of complete surgical tibial fractures fixed with internal rigid fixation (IRF) associated or not to the use of mineral trioxide aggregate (MTA) cement and treated or not with laser (λ = 780 nm, infrared) or LED (λ = 850 ± 10 nm, infrared) lights, 142.8 J/cm 2 per treatment, by means of Raman spectroscopy. Open surgical tibial fractures were created on 18 rabbits (6 groups of 3 animals per group, ∼8 months old) and fractures were fixed with IRF. Three groups were grafted with MTA. The groups of IRF and IRF + MTA that received laser or LED were irradiated every other day during 15 days. Animals were sacrificed after 30 days, being the tibia surgically removed. Raman spectra were collected via the probe at the defect site in five points, resulting in 15 spectra per group (90 spectra in the dataset). Spectra were collected at the same day to avoid changes in laser power and experimental setup. The ANOVA general linear model showed that the laser irradiation of tibial bone fractures fixed with IRF and grafted with MTA had significant influence in the content of phosphate (peak ∼960 cm -1 ) and carbonated (peak ∼1,070 cm -1 ) hydroxyapatites as well as collagen (peak 1,452 cm -1 ). Also, peaks of calcium carbonate (1,088 cm -1 ) were found in the groups grafted with MTA. Based on the Raman spectroscopic data collected in this study, MTA has been shown to improve the repair of complete tibial fractures treated with IRF, with an evident increase of collagen matrix synthesis, and development of a scaffold of hydroxyapatite-like calcium carbonate with subsequent deposition of phosphate hydroxyapatite., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The aim of the present study was to assess, by means of Raman spectroscopy, the repair of complete surgical tibial fractures fixed with wire osteosynthesis (WO) treated or not with infrared laser (λ780 nm) or infrared light emitting diode (LED) (λ850 ± 10 nm) lights, 142.8 J/cm 2 per treatment, associated or not to the use of mineral trioxide aggregate (MTA) cement. Surgical tibial fractures were created on 18 rabbits, and all fractures were fixed with WO and some groups were grafted with MTA. Irradiated groups received lights at every other day during 15 days, and all animals were sacrificed after 30 days, being the tibia removed. The results showed that only irradiation with either laser or LED influenced the peaks of phosphate hydroxyapatite (~ 960 cm -1 ). Collagen (~ 1450 cm -1 ) and carbonated hydroxyapatite (~ 1070 cm -1 ) peaks were influenced by both the use of MTA and the irradiation with either laser or LED. It is concluded that the use of either laser or LED phototherapy associated to MTA cement was efficacious on improving the repair of complete tibial fractures treated with wire osteosynthesis by increasing the synthesis of collagen matrix and creating a scaffold of calcium carbonate (carbonated hydroxyapatite-like) and the subsequent deposition of phosphate hydroxyapatite.