Biomodulation of Induced Tooth Movement by Three Methods, Corticopuncture, Photobiomodulation, and Their Combination: An Animal Study.

Objective: The aim of this study was to assess the effects of accelerated tooth movement (ATM) methods: corticopuncture (CP), photobiomodulation (PBM), and their combination (CP + PBM) by evaluating tooth displacement, alveolar bone changes, and molecular and cellular response compared with conventional induced tooth movement. Materials and methods: Tooth movement and bone changes were evaluated on days 1, 3, and 7 (9 animals per time point) using microtomography, histological, and immunohistochemical evaluation, at compression and tension sites. CP groups received two perforations in the palate and one mesial to the molars. PBM was performed using GaAlAs diode laser applied every other day for 7 days (λ = 808 nm, 100 mW) in two points for 15 sec/point and total energy of 3 J. Results: Tooth movement was significantly increased in all three ATM groups after 7 days compared with the control group (mean 0.24 mm) by 27% PBM (0.31 mm), 45% CP (0.35 mm), and 57% CP + PBM (0.38 mm) (p < 0.05). At the compression side, all ATM groups showed significant decrease in bone density on day 3 (p < 0.05) and significant less bone volume on day 7 compared with Control (p < 0.05). At the tension side, PBM group showed a significant increase in bone density and volume on day 3 (p < 0.05). Immunohistochemistry analysis showed that at the compression side, tartrate-resistant acid phosphatase-positive cells, RANKL, and tumor necrosis factor-alpha expression were highly marked of the PBM and the combined method groups (p < 0.05). PBM and CP + PBM groups showed a significant increase in expression Runt-related transcription factor 2 and osterix (p < 0.05) at the tension side. Conclusions: All ATM groups showed increase on tooth displacement with CP + PBM group showing greatest tooth displacement. CP method appears to stimulate bone catabolism, PBM has more effect on bone formation, and the combined method showing a synergistic effect on bone remodeling.

In vitro effects of photobiomodulation on cell migration and gene expression of ALP, COL-1, RUNX-2, and osterix in cementoblasts.

The aim of this study was to evaluate the effects of photobiomodulation (PBM) on cell migration and alkaline phosphatase (ALP), type I collagen (Col-1), runt-related transcription factor 2 (RUNX-2), and Osterix (OSX) gene expression in a cementoblast culture (OCCM-30), in a microenvironment mimicking an injury on the cementoblast layer, such as it occurs during root resorption. For this, OCCM-30 cells were cultured in 6-well plates and the following parameters were assayed: (1) migration by scratch assay and ALP, Col-1, Runx2, and Osx by real-time PCR. PBM was performed in two protocols using a LED device emitting light at 660 nm (± 30 nm). OCCM-30 cementoblasts were grown and divided into four groups: (1) negative control; (2) positive control (scratch); (3) scratch + PBM with a total energy of 36 J and energy density 1.6 J/cm2; and (4) scratch + PBM with a total energy of 72 J and energy density of 3.2 J/cm2. Data were statistically analyzed, with the level of significance set at 5%. Cementoblasts migrated from the edge of the scratch toward the center, and the wound closed after 24 h, with the PBM3.2J/cm2 group showing the higher cell migration compared with the other groups at 2 h, 6 h, 8 h, and 13 h (p < 0.05). The control and PBM1.6J/cm2 groups showed similar levels of cell migration, with no significant differences (p > 0.05). PBM3.2J/cm2 group exhibited greater ALP, Col-1, OSX, and RUNX2 in comparison with the other experimental groups (p < 0.05). Similar levels of all genes evaluated were observed between the PBM1.6J/cm2 group and the positive control group (p > 0.05). In conclusion, our findings support the effectiveness of photobiomodulation on cementoblast migration and gene expression, which may contribute to the formation of a new cementum layer.

Photobiomodulation increases uprighting tooth movement and modulates IL-1ß expression during orthodontically bone remodeling.

This study investigated the effects of photobiomodulation (PBM) in acceleration of orthodontic movement of inferior molar uprighting movement. Thirty-four individuals, with indication of molar uprighting movement for oral rehabilitation, were randomly divided in two groups: verticalization + PBM (808 nm, 100 mW, 1 J per point, 10 points and 25 J/cm2 ) or verticalization + PBM simulation. Elastomeric chain ligatures were changed every 30 days for 3 months. FBM was performed immediately, 24 h, 72 h, 1 and 2 months after activation. The primary outcome was the amount of uprighting movement. Secondary outcomes were pain, amount of medication, OHIP-14 questionnaire, and cytokine IL-1ß. PBM group increase uprighting movement when compared to control after 3 months and modulate IL-1ß expression. For pain control, the amount of medication and OHIP-14 no difference were found. This study suggests that PBM accelerates tooth movement during molar uprighting, due to modulation of IL-1ß during bone remodeling.

Can Collagen Membrane on Bone Graft Interfere with Light Transmission and Influence Tissue Neoformation During Photobiomodulation? A Preliminary Study.

Objective: This study qualitatively and quantitatively evaluated the transmission of light through a collagen membrane and the consequent local bone formation in a critical bone defect in vitro and in an animal model. Background: Currently, bone substitutes and collagen membranes are used to promote new bone formation; however, when associated with photobiomodulation, biomaterials can act as a barrier, hindering the passage of light radiation to the area to be treated. Methods: Light transmittance was evaluated in vitro with a power meter and a 100 mW, 808 nm laser source with and without membrane. Twenty-four male rats received a critical surgical defect of 5 mm in diameter in the calvarial bone, subsequently a biomaterial (Bio-Oss; Geistlich®, Switzerland) was applied, and the animals were divided into the following three groups: G1-collagen membrane and no irradiation; G2-collagen membrane and photobiomodulation (irradiation with 4 J of 808 nm); and G3-photobiomodulation (4 J) followed by a collagen membrane. Histomophometric analyses were performed at 7 and 14 days after euthanasia. Results: The membrane reduced the light transmittance (808 nm) by an average of 78%. Histomophometric analyses showed significant differences in new blood vessels on day 7 and bone neoformation on day 14. Irradiation without membrane interposition resulted in a 15% more neoformed bone compared with the control (G1), and 6.5% more bone compared with irradiation over the membrane (G2). Conclusions: The collagen membrane interferes with light penetration during photobiomodulation, decreases light dosimetry on the wound area, and interferes with bone neoformation.

Analysis of factors associated with the success of microimplant-assisted rapid palatal expansion.

INTRODUCTION: Success-related factors of microimplant-assisted rapid palatal expansion (MARPE) were evaluated, including age, palatal depth, suture, and parassutural bone thickness, suture density and maturation, and the relation to corticopuncture (CP) technique, as well as skeletal and dental effects. METHODS: Sixty-six cone-beam computed tomography scans were analyzed before and after rapid maxillary expansion procedures in 33 patients aged 18-52 years for both sexes. The scans were generated in digital imaging and communications in medicine file format and analyzed in the multiplanar reconstruction of the regions of interest. Palatal depth, suture thickness, density and maturation, age, and CP were assessed. To evaluate dental and skeletal effects, the sample was divided into 4 groups: successful MARPE (SM), SM + CP technique (SMCP), failure MARPE (FM), and FM + CP (FMCP). RESULTS: Successful groups presented more skeletal expansion and dental tipping than failure groups (P <0.05). The mean age of the FMCP group was significantly higher than the SM groups; suture and parassutural thickness significantly related to the success, and patients who received CP showed a success rate of 81.2% compared with 33.3% in the no CP group (P <0.05). Suture density and palatal depth did not show a difference between the success and failure groups. Suture maturation was higher in SMCP and FM groups (P <0.05). CONCLUSIONS: Older age, thin palatal bone, and higher stage of maturation can influence the success of MARPE. CP technique in these patients appears to have a positive impact, increasing the chance of treatment success.

UV-C light as an alternative for disinfecting orthodontic pliers / Luz UV-C como alternativa para desinfecção de alicates ortodônticos

Objetivo: Os ortodontistas usam alicates ortodônticos continuamente, e essas ferramentas têm um forte potencial para infecções nosocomiais. Este estudo teve como objetivo comparar a eficiência de três métodos de desinfecção de alicates ortodônticos. Material e Métodos: As pontas ativas de 26 alicates ortodônticos (cortadores distais e alicates Weingart) foram contaminadas com microrganismos, vírus e esporos S. aureus, E. coli e C. albicans. Os métodos de controle microbiano foram desinfecção com álcool 70%, esterilização com esferas de vidro (250 °C calor seco) e irradiação com luz ultravioleta (250 nm UV-C) por 30 e 60 segundos. O número de unidades formadoras de colônias (UFC) e unidades formadoras de placas (UFP) foi quantificado e comparado para cada microrganismo após incubação em placas de cultura. Resultados: Todas as pontas do alicate dos grupos que receberam luz ultravioleta ou foram submetidos à esterilização com esferas de vidro apresentaram número significativamente menor de esporos, bactérias e fungos do que suas respectivas amostras controle (p<0,001). A desinfecção física com luz UV-C pode representar uma alternativa confiável em comparação com outros métodos químicos e físicos devido ao aumento de microrganismos resistentes a produtos químicos e à emissão de subprodutos nocivos após o tratamento químico. Conclusão: Os métodos de controle microbiano testados foram eficazes na desinfecção de alicates ortodônticos, tornando a luz ultravioleta-C uma alternativa promissora para eliminar os microrganismos dos alicates (AU)

Objective: Orthodontists use orthodontic pliers continuously, and these tools have a strong potential for nosocomial infections. This study aimed to compare the efficiency of three methods for disinfecting orthodontic pliers. Material and Methods: The active tips of 26 orthodontic pliers (distal end cutters and Weingart pliers) were contaminated with S. aureus, E. coli, and C. albicans microorganisms, viruses, and spores. The microbial control methods were 70% alcohol disinfection, glass bead sterilization (250 °C dry heat), and ultraviolet light irradiation (250 nm UV-C) for 30 and 60 seconds. The number of colony-forming units (CFU) and plaque-forming units (PFU) was quantified and compared for each microorganism after incubation in culture plates. Results: All tips of the pliers in the groups that received ultraviolet light or were subjected to glass bead sterilization showed a significantly lower number of spores, bacteria, and fungi than their respective control samples (p<0.001). Physical disinfection with UV-C light may represent a reliable alternative compared to other chemical and physical methods due to the increase in microorganisms resistant to chemical products and the emission of harmful by-products after chemical treatment. Conclusion: The tested microbial control methods were effective in the disinfection of orthodontic pliers, making ultraviolet-C light a promising alternative to eliminate microorganisms from pliers (AU)

Assessment of a Biosafety Device to Control Contamination by Airborne Transmission during Orthodontic/Dental Procedures.

During the COVID-19 pandemic, dental professionals have faced high risk of airborne contamination between dentists, staff, and patients. The objective of this study was to evaluate the effect of an individual biosafety capsule in dentistry (IBCD) on reducing the dispersion of droplets and aerosols during orthodontic treatment and evaluate the clinician and patient's perception of using the IBCD. For the in-vitro part of the study, aerosol quantification was performed with and without the IBCD, using a nonpathogenic bacterial strain and viral strain in the reservoir and high-speed dental handpiece. Petri dishes with MRS agar were positioned from the head of the equipment at distances of 0.5, 1, and 1.5 m. After 15 minutes of passive aerosol sampling, the dishes were closed and incubated using standard aerobic conditions at 37°C for 48 hours to count colony forming units (CFUs). For the clinical part of the study, a questionnaire was sent to clinicians and patients to understand their perception of orthodontically treat and receive treatment using the barrier. The use of IBCD showed an effective means to reduce the dispersion of bacterial and viral contamination around 99% and 96%, respectively, around the main source of aerosol (p < 0.05). Clinical results showed a 97% bacterial reduction during patient's consultations (p < 0.05). The vast majority of clinicians and patients understand the importance of controlling the airborne dispersion to avoid contamination.

Photobiomodulation stimulates surrounding bone formation and increases stability of titanium alloy miniscrews in ovariectomized rats.

The number of older individuals (> 60 years) treated in orthodontic dental practice is constantly growing, and osteoporosis is a common disease within this age range. Orthodontic treatment for this group tends to be challenging, often requiring the use of mini-implants. Mini-implants are important accessories in orthodontic treatment that provide solutions to complex cases. Despite the high level of success, these devices are prone to failure if insufficient bone stability is achieved. This study aimed to evaluate the effects of photobiomodulation on bone neoformation around mini-implants using fluorescence analysis in ovariectomized rats. A total of 12 female rats (Wistar) were ovariectomized and divided into three groups: two groups of low-level laser therapy irradiation in two different protocols, as follows: in the PBM1 group, applications were performed using 2 J, for 20 s each for 48 h, 6 irradiations in total, and in the PBM2 group, a single application of 4 J was performed for 40 s, and the third group represented the control group, and no laser therapy was applied. Each rat received two mini-implants placed immediately behind the upper incisors, and 0 g of force was applied using a NiTi spring. All rats received two bone markers, tetracycline (days 0-4) and alizarin (days 7-10), for 5 days each. Both markers were bound to calcium, allowing visualization of bone neoformation through fluorescence microscopy. After 12 days, euthanasia was performed; the results revealed that both irradiated groups showed significantly greater bone neoformation compared to the control group (p < 0.05). Mini-implant stability was measured in all animals using the Periotest device on day 0 and on the day of euthanasia. A significant increase in stability was observed in the group that received more laser application (p < 0.05). Photobiomodulation had a positive effect on bone neoformation around mini-implants in ovariectomized rats, with an increase in stability when more irradiation was performed.

Evaluation of the cephalometric centroid point in individuals before and after the pubertal growth peak / Avaliação do comportamento do ponto cefalométrico centróide em pacientes antes e após o pico de crescimento da puberdade

ABSTRACT Objective: The purpose of this study was to evaluate the behavior of the Centroid point, known as the geometric center of the face, before and after the growth peak using lateral cephalometric x-ray. Methods: Sample consisted of 40 patients before and after pubertal peak of growth selected from the archive of the São Leopoldo Mandic Institute and Research Center, Campinas, Brazil. Anatomical structures, reference points, lines and planes were traced, and posteriorly a superimposition was performed using the palatal plane and a line perpendicular to this passage through the most posterior point of the pterygomaxillary fossa as reference. Later, the distance between the two centroid points (before and after the peak of puberty) was measured using the digital caliper, both horizontally and vertically. The palatal plane (x-axis) and a line perpendicular to this passage through the most posterior point of the pterygomaxilary fossa (y-axis) were chosen because they undergo minimal changes during growth. Results: No significant difference on the location of Centroid points on both X and Y axis (p >0.05) were observed between before and after the growth peak cephalometric tracings, showing an average change in positioning of 0.36mm on the X axis and 0.37mm on the Y axis. Conclusions: For this reason, this point can be indicated to be used clinically as a stable reference to evaluate craniofacial growth while performing superimposition methods.

RESUMO Objetivo: O objetivo deste estudo foi utilizar telerradiografias lateriais de pacientes antes e depois do pico de crescimento, e realizar sobreposições de desenhos cefalométricos para avaliar o comportamento do ponto Centróide, o centro geométrico da face. Métodos: Foram selecionadas telerradiografias de norma lateral de 40 pacientes tomadas antes e depois de seu pico de puberdade do acervo de Ortodontia do Centro de Pesquisas Odontológicas São Leopoldo Mandic, na cidade de Campinas. As estruturas e traçados cefalométricos devidamente desenhados, foram sobrepostos tendo como referência estável o plano palatal e a linha perpendicular a esta que passe pelo ponto mais posterior da fossa pterigomaxilar. Em seguida foi medida a distância entre os dois pontos centroides (antes e após o pico de puberdade) por meio de paquímetro digital tanto no sentido horizontal quanto no vertical. O plano palatal (eixo x) e a linha perpendicular a esta que passe pelo ponto mais posterior da fossa pterigomaxilar (eixo y) foram escolhidos por sofrerem mínimas alterações nas suas direções durante o crescimento. Resultados: Não foi observada diferença estatisticamente significante na localização dos pontos Centróides em ambos os eixos X e Y (p>0,05) quando comparou-se os traçados antes e depois do pico de crescimento, mostrando uma alteração, em média, no posicionamento de 0,36mm no Eixo X e 0,37mm no Eixo Y. Conclusão: Assim, este ponto pode ser utilizado como referência estável para avaliação do crescimento craniofacial nas sobreposições.

Photobiomodulation inhibits inflammation in the temporomandibular joint of rats.

Photobiomodulation (PBM) has been applied as a non-invasive technique for treating temporomandibular joint symptoms, especially on painful condition's relief, however the anti-inflammatory mechanism underlying the effect of PBM remains uncertain. This study aims to evaluate the mechanisms of action of PBM (808 nm) in a carrageenan-induced inflammation on temporomandibular joint (TMJ) of rats. In this study male Wistar rats were pre-treated with irradiation of a low-power diode laser for 15 s on TMJ (infra-red 808 nm, 100 mW, 50 J/cm2 and 1.5 J) 15 min prior an injection in the temporomandibular joint of carrageenan (100 µg/TMJ). 1 h after the TMJ treatments, the rats were terminally anesthetized for joint cavity wash and periarticular tissues collect. Samples analysis demonstrated that PBM inhibit leukocytes chemotaxis in the TMJ and significantly reduces amounts of TNF-α, IL-1ß and CINC-1. In addition, Western blotting analysis demonstrated that PBM significantly decreased the protein levels of P2X3 and P2X7 receptors in the periarticular tissues. On the other hand, PBM was able to increase protein level of IL-10 (anti-inflammatory cytokine). In summary, it is possible to suggest that PBM inhibit inflammatory chemotaxis, modulation the balance of the pro- and anti-inflammatory characteristics of inflammatory cells.

Autophagy upregulation may explain inhibition of oral carcinoma in situ by photobiomodulation in vitro.

There is currently no clear understanding on the pathways involved in the process of cell inhibition by photobiomodulation (PBM). The present study evaluated the influence of PBM on the expression of autophagy markers in vitro in an in situ model of oral carcinoma. Oral squamous cell carcinoma (Cal27) and stromal fibroblasts (FG) cultures were used. The independent variables were 'cell type' (FG and CAL27) 'culture condition' (monocultures or co-cultures) and PBM (placebo and 36 J/cm2). The cultures were irradiated from a red LED source for mRNA expression and protein expression analyses. The autophagy markers evaluated were Beclin-1, LC3B and p62 as well as adjuvant markers (BAX Bcl-2, VEGF, CD105, CD34, PRDX1, PRDX4 and GRP78). The Cal27 cells upregulated the autophagy markers upon exposure to PBM both at the mRNA and protein expression levels, providing evidence to explain malignant cell inhibition by PBM.

Antimicrobial resistance of bacterial strains in patients undergoing orthodontic treatment with and without fixed appliances.

OBJECTIVES: To identify microorganisms isolated from patients wearing fixed orthodontic appliances and to evaluate the resistance of isolated bacterial strains to different antimicrobials. MATERIALS AND METHODS: Seventeen healthy patients wearing a fixed orthodontic appliance (group 1) and six nonwearers (group 2, control group) were evaluated. The biofilm that formed around the orthodontic brackets was collected, and the samples were then plated in a chromogenic medium (chromIDT, bioMérieux). Colony-forming units (CFUs) were isolated and inoculated in blood-agar medium. Automated biochemical tests (VITEK 2, bioMérieux) were carried out to identify the genus and species of the microorganisms and the resistance provided by 43 drugs (37 antibacterial and 6 antifungal). RESULTS: The most prevalent microbial genera identified in group 1 were Streptococcus (24.0%), Staphylococcus (20.0%), Enterobacter (12.0%), Geobacillus (12.0%), and Candida (12.0%), and the most frequent species were Enterobacter cloacae complex (13.6%) and Staphylococcus hominis (13.6%). In group 2, the most prevalent genera were Streptococcus (57.1%), Staphylococcus (14.2%), Sphingomonas (14.2%), and Enterobacter (14.2%). With regard to antimicrobial resistance, 14 of 19 (74%) isolated bacterial strains were found to be resistant to at least 1 of the tested antimicrobials. CONCLUSIONS: The findings of the present study suggest that patients undergoing orthodontic treatment with fixed appliances have a more complex biofilm with a higher level of bacterial resistance.

A novel dental biosafety device to control the spread of potentially contaminated dispersion particles from dental ultrasonic tips.

Strategies to return to dental practice in pandemic times is a new challenge due to the generation and spread of potentially contaminated dispersion particles (PCDP) that may contain the SARS-CoV-2, the etiological factor of the COVID-19 disease. Due to the significant dispersion of PCDP in the dental environment, the use of equipment such as ultrasonic tips have been inadvisable during the pandemic. Several clinical procedures, however, benefit from the use of such equipment. Thus, using a microbial dispersion model of PCDP, the aim of this study was to compare the dispersion caused by the dental drill (DD) an ultrasonic tip (UT) alone and the UT coupled with a Spray control (SC) device. The DD, UT (with or without the SC) were activated for one minute having had the water from the reservoir replaced with a suspension of Lactobacillus casei Shirota (1.5 x 108 CFU/mL). Petri dishes containing MRS agar were positioned at 50cm, 100cm and 150cm from the headrest of the dental chair at different angles (0 degree and 90 degrees). At 50 cm, the mean CFU (standard deviation) of L. casei Shirota was 13554.60 (4071.03) for the DD, 286.67 (73.99) for the US (97.89% reduction), and 4.5 (0.58) CFU for the UT-SC (p < 0.0001), establishing a further 98.43% reduction between UT and UT with SC. The UT with SC model proved effective in reducing dispersion from the UT, endorsing its use as an additional strategy to reduce PCDP in the dental environment in times of pandemic.

Evaluation of the effects of photobiomodulation on orthodontic movement of molar verticalization with mini-implant: A randomized double-blind protocol study.

INTRODUCTION: Loss of a dental element can generate several repercussions in the stomatognathic system. According to the latest survey by the Ministry of Health, in 2010, Brazilian adults had, on average, 7 missing teeth. This loss may lead to movement of the adjacent teeth and the antagonist, which would make prosthetic rehabilitation harder to do. Anchoring systems, such as mini-implants, have been increasingly used as a treatment option because they act with heavy but controlled forces and without side effects. Recent studies have shown that photobiomodulation (PBM) can accelerate orthodontic movement in molar intrusion. The objective of this study will be to evaluate the effect of PBM on the acceleration of the orthodontic movement of molar verticalization and its effect on pain and inflammation of the periodontal tissues. PATIENT CONCERNS:: the concerns assessments will be done over the study using anamnesis interviews and specific questionnaire. DIAGNOSIS: verticalization will be evaluated by clinical and radiographic analysis. INTERVENTIONS: Thirty four healthy patients aged 30 to 60 years, who need to recover the prosthetic space for oral rehabilitation after loss of the posterior inferior dental elements and inclination of the adjacent element, will be randomly divided into 2 groups: G1 (control group) - verticalization by mini-implant + PBM simulation (placebo); G2 (experimental group) - verticalization by mini-implant + PBM. The movements will occur with the aid of mini-implants and elastomeric chains ligatures. The PBM will occur with diode laser application, 808 nm, 100 mW, receiving 1J per point, 10 seconds, 10 points (5 per buccal and 5 per lingual) and radiant exposure of 25 J/cm. The orthodontic forces of verticalization (corresponding to any exchange of elastomeric ligation) will be applied every 30 days and the PBM will be applied immediately, 3 and 7 days of each month, for a period of 3 months. The crevicular gingival fluid (CGF) will be collected on the 1st, 3rd, and 7th days after the first activation, and then on the 3rd day of the following 2 months. OUTCOMES: Interleukins IL1ß, IL-6, IL-8, IL-10, and TNF-α will be analyzed by ELISA. Panoramic radiography will be performed at baseline and 90 afterwards to ascertain the amount (in degrees) of verticalization. To evaluate the pain, the Visual Analog Scale (VAS) will be used in all the consultations, and to evaluate the quality of life, the Oral Health Impact Profile (OHIP-14) questionnaire will be applied. Analgesics will be given and the quantity of drugs will be counted. If the data are normal, they will be submitted to Student t test. The data will be presented as means ± SD and the value of p will be defined as <0.05. DISCUSSION: This protocol will determine the effectiveness of photobiomoduation regarding the orthodontic movement of molar verticalization. ETHICS AND DISSEMINATION: This protocol received approval from the Human Research Ethics Committee of Universidade Nove de Julho (certificate number: 3 533 219). The data will be published in a peer-reviewed periodical.

Photodynamic Activity on Biofilm in Endotracheal Tubes of Patients Admitted to an Intensive Care Unit.

Ventilator-associated pneumonia (VAP) is an infection that arises after endotracheal intubation affecting patients under intensive care. The presence of the endotracheal tube (ETT) is a risk factor since it is colonized by multispecies biofilm. Antimicrobial photodynamic therapy (aPDT) could be a strategy to decontaminate ETTs. We verify if methylene blue (MB) associated with external illumination of the ETT could be an alternative to destroy biofilm. We performed an in vitro and ex vivo study. In vitro study was performed with P. aeruginosa biofilm grew over ETT for 7 days. After treatment, the surviving cells were cultured for 3 days and the biofilm was analyzed by crystal violet absorbance. Ex vivo study employed ETT obtained from extubated patients. aPDT was performed with MB (100 µm) and red LED (λ = 640±20 nm). We quantified the biofilm thickness and used scanning electron microscopy and fluorescence technique to verify morphological and functional changes after aPDT. Our results showed that bacteria remain susceptible to aPDT after sequential treatments. We also attested that aPDT can reduce biofilm thickness, disrupt biofilm attachment from ETT surface and kill microbial cells. These data suggest that aPDT should be investigated to decrease VAP incidence via ETT decontamination.

Reliability of a Centroid method to estimate head position in cephalometric diagnosis / Confiabilidade de um método baseado no ponto Centróide para estimar a posição da cabeça no diagnóstico cefalométrico

ABSTRACT Objective The objective of this study was to 1) evaluate the reproducibility of natural head position (NHP) in different professional groups; 2) compare three cephalometric methods of estimating head position to the established natural head position and 3) investigate the applicability of a new method to estimated head position using a Centroid method. Methods The sample consisted of 105 individual cephalometric tracings and photographs. For the first evaluation, copies of the lateral photographs were reproduced for each patient and 3 professionals with different expertise (experienced orthodontists, orthodontic students and orthognatic surgeon) were instructed to position the photographs in NHP. Later, 3 different methods to obtain NHP were assessed: 1) the Frankfort Horizontal Plane (FRANK), 2) Sella-Nasion 7º Line (SN7) and 3) proposed Horizontal Reference Line based on Centroid. Angles formed by the evaluated planes/lines and True Vertical Line obtained were measured. Gender and skeletal discrepancy were considered. Results The results showed a significant difference between NHP obtained from orthodontists and surgeons compared to students (p<0.0001). Also results showed no effect of skeletal classification and gender did on measurement (p>0.05). Both SN minus 7º and FRANK methods showed a high variability (p < 0,01) compared to Centroid method. Conclusion NHP may be affected by the professional experience. The proposed horizontal line based on Centroid is a valid method for estimating head position, thus, may be indicated to use as a diagnostic tool in Orthodontics and Orthognatic Surgery.

RESUMO Objetivo Os objetivos deste estudo foram 1) avaliar a reprodutibilidade da posição natural da cabeça (PNC) em diferentes grupos de profissionais; 2) comparar três métodos cefalométricos para estimar a posição da cabeça e compará-los à posição natural estabelecida da cabeça e 3) investigar a aplicabilidade de um novo método para estimar a posição da cabeça usando o método Centróide. Métodos A amostra foi composta por 105 traçados cefalométricos e fotografias individuais. Para a primeira avaliação, cópias das fotografias laterais foram reproduzidas para cada paciente e três profissionais com diferentes conhecimentos (ortodontistas experientes, estudantes de ortodontia e cirurgião ortognático) foram instruídos a posicionar as fotografias no PNC. Posteriormente, foram avaliados três métodos diferentes para obter posição estimada da cabeça: 1) o Plano Horizontal de Frankfort (FRANK), 2) a Linha Sella-Nasion 7º (SN7) e 3) a Linha de Referência Horizontal proposta, baseada em Centróide. Os ângulos formados pelos planos/linhas avaliados e pela linha vertical verdadeira obtidos foram medidos. Foram considerados a discrepância esquelética e o gênero. Resultados Os resultados mostraram uma diferença significativa entre o PNC obtido por ortodontistas e cirurgiões em relação aos estudantes (p <0,0001). Os métodos SN7 e FRANK apresentaram alta variabilidade (p <0,01), enquanto o método baseado em Centróide mostrou menor variabilidade. Conclusão a PNC pode ser afetada pela experiência profissional. A linha horizontal proposta baseada em Centróide é um método válido para estimar a posição da cabeça, portanto, pode ser indicada para uso como ferramenta de diagnóstico em Ortodontia e Cirurgia Ortognática.

High energy density LED-based photobiomodulation inhibits squamous cell carcinoma progression in co-cultures in vitro.

Current management of oral potentially malignant disorders is careful monitoring. Unfortunately, the 'watch and wait' approach only generates anxiety and a feeling of powerlessness, especially to those caring for patients. Photobiomodulation (PBM) has emerged as a potential strategy to inhibit possible transforming cells. The aim of this study was to investigate the effect of LED-based PBM on the progression of malignant invasion into a fibroblast-based stroma. An in vitro model of carcinoma in situ (CIS) containing stromal fibroblasts and carcinoma cells in co-culture was used to study the effect of PBM on the expansion of CIS colonies. A second model of co-culture (cells separated by membrane), was used to study cell counts, viability and apoptosis following PBM at high doses (36 J/cm2). The data was analyzed using Kruskal-Wallis, Dunn's test and non-linear regression, wherever appropriate. PBM was able to inhibit the expansion of CIS colonies as well as the total number of colonies after 72 h of treatment (p < 0.05). Cell viability, apoptosis and death assays revealed an overall advantage of stromal fibroblasts over carcinoma cells after high-dose PBM. In conclusion, LED-based PBM at high doses inhibited the progression and number of oral squamous cell carcinoma colonies without affecting the surrounding stromal fibroblasts in vitro.

Effect of photodynamic therapy potentiated by ultrasonic chamber on decontamination of acrylic and titanium surfaces.

Photodynamic Therapy (PDT) is an alternative to surface decontamination that is based on the interaction between a non-toxic photosensitizer (PS) and a light source to allow for the formation of reactive oxygen species. The objective of this study was to test a new patented device - the "Ultrasonic Photodynamic Inactivation Device" (UPID) under the patent deposit MU-BR 20.2018.00.9356-3 - for the photodynamic inactivation on contaminated acrylic plates and titanium disk. This new low cost device contains light emitting diodes (LEDs) and was built in a stainless-steel container for better light distribution. In addition, 28 waterproof red LEDs plates, with a wavelength of 660 nm were used, containing three irradiators in each plate, for which the irradiation distribution and the spectral irradiance on all 6 internal faces of this device were calculated. The effect of red LED irradiation (660 nm) methylene blue (MB) (100 µmol/L) diluted in water or 70% alcohol on three types of microorganisms: Candida albicans ATCC 10231, Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922. In order to estimate the effects of PDI, acrylic plates and Titanium disks were contaminated by bacterial suspensions (3 × 108 CFU/mL), then treated with a solution of MB for 30 min, followed by irradiation for 30 min (0.45 J/cm2). Microbial inhibition was evaluated by counting the number of colony forming units (CFU), compared to the control group. The results showed that the UPID promoted significant reduction (p < 0.001) of the microorganism when compared with the positive control. The new device promoted an effective microbial inhibition on the surfaces tested and, thus, makes possible new studies. The perspective is that this new device may be a low-cost and non-toxic alternative to the disinfection of biomedical devices, non-critical instruments and also for use in the food industry.

Effects of Photobiomodulation on Root Resorption Induced by Orthodontic Tooth Movement and RANKL/OPG Expression in Rats.

The aim of this study was to evaluate the effects of photobiomodulation on the repair of induced root resorption (RR) after orthodontic tooth movement. Twenty male rats were used in this study. Forty right and left upper first molars were evaluated and divided into four groups (n = 10): negative control group (NC), no tooth movement or irradiation; positive control group (PC), induced tooth movement and root resorption; conventional treatment group (CT), force was removed after 7 days; and photobiomodulation group (PBM) after force removal molars were irradiated every 48 h for 7 days using GaAlAs diode laser (810 nm). Energy per point was 1.5 J (100 mW, 15 s, 75 J cm-2 ). NC and PC were euthanized on day 7; CT and PBM on day 14. Histomorphometric and immunohistochemsitry analyses showed increase in area of root resorption in all groups (P < 0.05) compared to NC. RR lacunae were larger in CT compared to PC and PBM at the compression side of the distal root. OPG was higher in PBM group (P < 0.05). PBM group showed low expression of RANKL compared to PC and CT on the tension side. PBM can potentially affect RR progression by increasing OPG expression in the compression area and decreasing number of clastic cells in the root surface.

Assessment of respiratory muscle strength and airflow before and after microimplant-assisted rapid palatal expansion.

OBJECTIVES: To assess alterations in respiratory muscle strength and inspiratory and expiratory peak flow, as well as skeletal and dental changes in patients diagnosed with transverse maxillary deficiency before and after microimplant-assisted rapid maxillary expansion (MARPE). MATERIALS AND METHODS: Twenty patients (13 female and 7 male) were assessed by respiratory tests in three different periods: T0 initial, T1 immediately after expansion, and T2 after 5 months. Tests included: maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP), oral expiratory peak flow, and inspiratory nasal flow. Cone-beam computed tomography measurements were performed in the maxillary arch, nasal cavity, and airway before and immediately after expansion. RESULTS: There was a significant increase in MIP between T0 and T2 and MEP between T0 and T1 (P<.05). Oral and nasal peak flow increased immediately after and 5 months later, especially in patients with initial signs of airway obstruction (P<.05). In addition, after expansion there was a significant enlargement of the nasal cavity, alveolar bone, and interdental widths at the premolar and molar region. Molars tipped buccally (P<.05) but no difference was found in premolar inclination. MARPE increased airway volume significantly. CONCLUSIONS: Skeletal changes promoted by MARPE directly affected airway volume, resulting in a significant improvement in muscle strength and nasal and oral peak flow.