The influence of iliotibial tract thickness on clinical outcomes in women with patellofemoral pain.

BACKGROUND: The assessment of iliotibial tract thickness by ultrasonography may help identify a key, previously unexplored factor that may contribute directly to the homeostasis imbalance of the femoropatellar joint in people with patellofemoral pain (PFP). OBJECTIVES: To compare the iliotibial tract thickness of people with PFP and asymptomatic people; and to correlate the iliotibial tract thickness with self-reported pain and function of people with PFP. METHODS: Eighty women, separated into two groups: PFP group (n = 40) and control group consisting of asymptomatic participants (CG; n = 40). The participants answered the Anterior Knee Pain Scale (AKPS) questionnaire, to identify the self-reported knee function; they evaluated the pain in millimeters by the Visual Analog Scale for pain (VAS). For the imaging evaluation, an ultrasound was used, with a linear transducer at the distal portion of the iliotibial tract (coronal plane), with the participants positioned in dorsal decubitus, with 20° of knee flexion. The iliotibial band was visualized in its long axis, and three sequential images were recorded between the lateral femoral condyle and the lateral tibial condyle. The measurements were normalized and correlated. RESULTS: The groups had no differences (P > 0.001) between participants for: age/weight/height/IMC. Participants in the PFP group had moderate levels of pain (58 + 2.1 mm), considerable self-reported functional limitation (d = 3.05) and greater iliotibial tract thickness compared with the CG (d = 2.41). CONCLUSION: The iliotibial tract of women diagnosed with PFP have greater thickness compared with asymptomatic women. There was no association between iliotibial tract thickness and subjective measures of pain and function.

Photobiomodulation Effectiveness in Treating Androgenetic Alopecia.

Background: Androgenetic alopecia (AGA) is a genetically determined condition, which leads to progressive hair loss (HL) of the vertex, affects hair follicles, and promotes partial or total HL. It may be related to important psychological and social distress. Objective: The aim of the study was to evaluate the effects of photobiomodulation (PBM) in patients with AGA. Methods: Twenty-five men 20-54 years of age participated in this study. The irradiations were punctual, in contact mode, with 1 cm between each point covering the entire affected area. A red low-level laser (λ = 660 nm) (Recover®, MMOptics, São Carlos, Brazil) was used with 100 mW, 30 sec, and 3 J per point, twice a week on alternate days for 10 weeks. Evaluations were made by photographic records from the same area before any intervention (T1), after 5 weeks (T2), after 10 weeks (T3). Two blinded evaluators using the ImageJ® software assessed the hair density. Results: The hair density evaluation showed a significant increase in hair count between T1 and T2 (p = 0.0004) and between T1 and T3 (p = 0.0285), however between T2 and T3 no statistical difference was found (p > 0.05). Conclusions: PBM provides a stimulus for hair density in 5 weeks. After this period, we observed that after five extra sessions, it does not increase hair density in the treated region. This study showed that the PBM is effective and promoted safe results with a reduced number of sessions for the AGA treatment.

Use of photodynamic therapy and photobiomodulation as alternatives for microbial control on clinical and subclinical mastitis in sheep.

Evaluate the effects of antimicrobial photodynamic therapy (aPDT) and photobiomodulation (PBM) as alternatives in the treatment of mastitis in sheep. A total of 100 sheep were evaluated, and four teats with clinical mastitis and 16 teats with subclinical mastitis were selected. Milk was collected for isolation and identification of microorganisms. They were grown on TSA, EMB, and MacConkey agar for 24 h, and the microorganisms were identified by Gram stain and biochemical tests. The ceilings were subdivided into four groups: G1, treatment with photosensitizer; G2, treatment with PBM (diode laser λ = 660 nm); G3, aPDT with methylene blue, and G4, control group. Milk samples were collected before, 24 and 48 h after treatments. Cases of subclinical mastitis presented coagulase-negative Staphylococcus and Streptococcus spp, and clinical mastitis had Escherichia coli grow from the samples. The treatments decrease the total bacterial count of negative coagulase Staphylococcus, Streptococcus spp, and Escherichia coli. Comparing the treatments, aPDT stood out, as it was able to photoinactivate all bacteria. Treatment with methylene blue photosensitizer, PBM, and aPDT induced the initial microbial reduction, but aPDT was more effective 48 h after treatment.

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.

Atletas paralímpicos brasileiros: uma avaliação da saúde bucal / Brazilian paralympic athletes: an evaluation of oral health status

Objetivo: o objetivo deste trabalho foi avaliar as condições de saúde bucal e investigar hábitos de vida que poderiam revelar fatores de risco para cárie dentária de atletas paraolímpicos paratletas brasileiros e, assim, identificar quais problemas de saúde bucal podem impactar seu desempenho, possibilitando a implementação de políticas públicas voltadas para essa população. Material e Métodos: os dados foram coletados de atletas participantes de um programa financiado pelo governo denominado "Odontologia Esportiva para Atletas de Alto Desempenho", realizado no Instituto de Pesquisa em Saúde - INPES em São Paulo, Brasil. Um total de 96 atletas paralímpicos de alto desempenho foram examinados por 4 dentistas treinados e calibrados. Higiene bucal, relatos de dor bucal, exame da ATM, índice de má oclusão e informações sociodemográficas foram os dados coletados. Resultados: A idade dos atletas variou de 18 a 56 anos, com média de idade de 34 anos. A maioria dos atletas era nadadora (55,2%). 27,1% apresentaram sangramento gengival e 31,0% relataram sensibilidade dentária. 47,9% tinham classe I (Angle) e a maioria dos atletas (71,9%) não apresentou sinais clínicos de disfunção temporomandibular. A média do índice de cariados, perdidos e obturados (CPOD) foi de 10,5, variando de 0 a 28. Conclusões: os exames clínicos indicam uma população que necessita significativamente de procedimentos preventivos e restauradores de saúde bucal. Esperamos que nossos dados sejam úteis e ajudem as autoridades responsáveis na criação de políticas públicas curativas e preventivas para a população analisada.

Objective: To estimate the oral health status and investigate lifestyle habits that may reveal risk factors for dental caries of Brazilian competitive athletes and thus identify which oral health problems may impact their performance, enabling the implementation of public policies focused on this population. Material and Methods: This study collected data to describe the oral health status of Brazilian Paralympics Athletes participating in a government funded program named "Sports Dentistry for High Performed Athletes" performed at the Institute of Health Research ­ INPES in Sao Paulo, Brazil. A total of 96 high performed paralympic athletes were screened by 4 trained and calibrated dentists. Oral hygiene, reports of oral pain, TMJ examination, malocclusion index and sociodemographic information were recorded. Results: The age of the athletes ranged from 18 to 56 years, with a mean age of 34 years. The majority of the athletes were swimmers (55.2%). 27.1% had gum bleeding, and 31.0% reported tooth sensitivity. 47.9 % had class I (Angle) and most athletes (71.9%) didn´t show clinical signs of temporomandibular disorders. The mean of decayed, missing and filled index (DMFT) was 10.5, varying 0 to 28. Conclusions: clinical examinations indicate a population that significantly needs preventive and restorative oral health procedures. We hope that our data will be useful and assist the responsible authorities in creating curative and preventive public policies for the analyzed population.

Evaluation of red light scattering in gingival tissue - in vivo study.

Antimicrobial photodynamic therapy (aPDT) has been used to treat periodontal disease, thus the aim of this study was to investigate red light (ʎ = 660 nm) attenuation in gingival tissue. This clinical trial included 30 patients with chronic periodontitis; three incisors from each patient were selected for the experimental procedures. A laser source with a radiant power output of 100 mW was used. Two digital photographs were taken of each selected incisor (in frontal and occlusal position). The images were analyzed in the ImageJ program. The results demonstrated that at a 3 mm distance from the laser probe, there is an attenuation of light intensity of 50%, along frontal and occlusal views. Light attenuation in gingival tissue should be considered when setting optimal parameters for antimicrobial photodynamic therapy or photobiomodulation.

Type I and Type II Photosensitized Oxidation Reactions: Guidelines and Mechanistic Pathways.

Here, 10 guidelines are presented for a standardized definition of type I and type II photosensitized oxidation reactions. Because of varied notions of reactions mediated by photosensitizers, a checklist of recommendations is provided for their definitions. Type I and type II photoreactions are oxygen-dependent and involve unstable species such as the initial formation of radical cation or neutral radicals from the substrates and/or singlet oxygen (1 O21 ∆g ) by energy transfer to molecular oxygen. In addition, superoxide anion radical (O2·-) can be generated by a charge-transfer reaction involving O2 or more likely indirectly as the result of O2 -mediated oxidation of the radical anion of type I photosensitizers. In subsequent reactions, O2·- may add and/or reduce a few highly oxidizing radicals that arise from the deprotonation of the radical cations of key biological targets. O2·- can also undergo dismutation into H2 O2 , the precursor of the highly reactive hydroxyl radical (·OH) that may induce delayed oxidation reactions in cells. In the second part, several examples of type I and type II photosensitized oxidation reactions are provided to illustrate the complexity and the diversity of the degradation pathways of mostly relevant biomolecules upon one-electron oxidation and singlet oxygen reactions.

Exploring the effects of low-level laser therapy on fibroblasts and tumor cells following gamma radiation exposure.

Ionizing radiation (IR) induces DNA damage and low-level laser therapy (LLLT) has been investigated to prevent or repair detrimental outcomes resulting from IR exposure. Few in vitro studies, however, explore the biological mechanisms underlying those LLLT benefits. Thus, in this work, fibroblasts and tumor cells are submitted to IR with doses of 2.5 Gy and 10 Gy. After twenty-four-h, the cells are exposed to LLLT with fluences of 30 J cm-2 , 90 J cm-2 , and 150 J cm-2 . Cellular viability, cell cycle phases, cell proliferation index and senescence are evaluated on days 1 and 4 after LLLT irradiation. For fibroblasts, LLLT promotes - in a fluence-dependent manner - increments in cell viability and proliferation, while a reduction in the senescence was observed. Regarding tumor cells, no influences of LLLT on cell viability are noticed. Whereas LLLT enhances cell populations in S and G2 /M cell cycle phases for both cellular lines, a decrease in proliferation and increase in senescence was verified only for tumor cells. Putting together, the results suggest that fibroblasts and tumor cells present different responses to LLLT following exposure to gamma-radiation, and these promising results should stimulate further investigations. Senescence of tumor cells and fibroblasts on the 4th day after ionizing radiation (IR) and low-level laser therapy (LLLT) exposures. The number of senescent cells increased significantly for tumor cells (a) while for fibroblasts no increment was observed (b). The blue collor indicates senescence activity.

Light therapy modulates serotonin levels and blood flow in women with headache. A preliminary study.

In this study, we looked at the possible effects of low-level laser therapy (LLLT) on blood flow velocity, and serotonin (5-HT) and cholinesterase levels in patients with chronic headache associated with temporomandibular disorders (TMD). LLLT has been clinically applied over the past years with positive results in analgesia and without the report of any side effects. The understanding of biological mechanisms of action may improve clinical results and facilitate its indication. Ten patients presenting headache associated with TMD completed the study. An 830-nm infrared diode laser with power of 100 mW, exposure time of 34 s, and energy of 3.4 J was applied on the tender points of masseter and temporal muscle. Blood flow velocity was determined via ultrasound Doppler velocimetry before and after laser irradiation. The whole blood 5-HT and cholinesterase levels were evaluated three days before, immediately, and three days after laser irradiation. Pain score after treatment decreased to a score of 5.8 corresponding to 64% of pain reduction (P < 0.05). LLLT promoted a decrease in the blood flow velocity (P < 0.05). In addition, the 5-HT levels were significantly increased three days after LLLT (P < 0.05). The cholinesterase levels remained unchanged at the analyzed time points (P > 0.05). Our findings indicated that LLLT regulates blood flow in the temporal artery after irradiation and might control 5-HT levels in patients suffering with tension-type headache associated to TMD contributing to pain relief.

Comparative clinical study of light analgesic effect on temporomandibular disorder (TMD) using red and infrared led therapy.

Low-level laser therapy (LLLT) has been widely applied in pain relief in several clinical situations, including temporomandibular disorders (TMD). However, the effects of LED therapy on TMD has not been investigated. This study aims to evaluate the effects of red and infrared LEDs on: (1) tissue temperature in ex vivo and (2) pain relief and mandibular range of motion in patients with TMD. Thirty patients between 18 and 40 years old were included and randomly assigned to three groups. The two experimental groups were: the red LED (630 ± 10 nm) group and the infrared LED (850 ± 10 nm) group. The irradiation parameters were 150 mW, 300 mW/cm(2), 18 J/cm(2), and 9 J/point. The positive control group received an infrared laser (780 nm) with 70 mW, 1.7 W/cm(2), 105 J/cm(2), and 4.2 J/point. LED and laser therapies were applied bilaterally to the face for 60 s/point. Five points were irradiated: three points around the temporomandibular joint (TMJ), one point for the temporalis, and one near the masseter. Eight sessions of phototherapy were performed, twice a week for 4 weeks. Pain induced by palpating the masseter muscle and mandibular range of motion (maximum oral aperture) were measured at baseline, immediately after treatment, 7 days after treatment, and 30 days after treatment. There was an increase in tissue temperature during both the red and the infrared LED irradiation in ex vivo. There was a significant reduction of pain and increase of the maximum oral aperture for all groups (p ≥ 0.05). There was no significant difference in pain scores and maximum oral aperture between groups at baseline or any periods after treatment (p ≥ 0.05). The current study showed that red and infrared LED therapy can be useful in improving outcomes related to pain relief and orofacial function for TMD patients. We conclude that LED devices constitute an attractive alternative for LLLT.

Effects of ionic strength on the antimicrobial photodynamic efficiency of methylene blue.

Antimicrobial photodynamic therapy (APDT) may become a useful clinical tool to treat microbial infections, and methylene blue (MB) is a well-known photosensitizer constantly employed in APDT studies, and although MB presents good efficiency in antimicrobial studies, some of the MB photochemical characteristics still have to be evaluated in terms of APDT. This work aimed to evaluate the role of MB solvent's ionic strength regarding dimerization, photochemistry, and photodynamic antimicrobial efficiency. Microbiological survival fraction assays on Escherichia coli were employed to verify the solution's influence on MB antimicrobial activity. MB was evaluated in deionized water and 0.9% saline solution through optical absorption spectroscopy; the solutions were also analysed via dissolved oxygen availability and reactive oxygen species (ROS) production. Our results show that bacterial reduction was increased in deionized water. Also we demonstrated that saline solution presents less oxygen availability than water, the dimer/monomer ratio for MB in saline is smaller than in water and MB presented a higher production of ROS in water than in 0.9% saline. Together, our results indicate the importance of the ionic strength in the photodynamic effectiveness and point out that this variable must be taken into account to design antimicrobial studies and to evaluate similar studies that might present conflicting results.

The influence of red laser irradiation timeline on burn healing in rats.

Low-level laser therapy (LLLT) promotes biomodulation of wound healing and literature reports that light delivery during the inflammation could play a different role compared with latter phases of the healing process. The objective of this study was to investigate whether single dose of a red laser (λ = 660 nm) is different from fractionated delivery protocol in full thickness burns. Two lesions were inflicted on the back of 36 rats. In the fractionated dose group (FG), the lesions were irradiated with 1 J/cm² on days 1, 3, 8, and 10 post-wounding. In the single dose group (SG), the lesions were irradiated with 4 J/cm² on day 1, immediately after injury. Control lesions (CG) received no light and were left to heal spontaneously. Blood flow was measured on days 1, 3, 8, 10, 15, and 21 using laser Doppler flowmetry. Animals were killed on days 3, 8, 10, 15, and 21. Skin specimens were obtained and routinely processed for hematoxylin and eosin. The specimens were evaluated according to differential leukocyte counting and angiogenesis. Statistical analysis was performed, and significance was accepted at p < 0.05. Irradiated groups showed a peak of new vessels on day 15 while, for CG, the peak was on day 21. On day 21, FG exhibited a significantly greater number of cumulative neutrophils while SG showed a higher number of mononuclear cells. Our results confirm that both protocols used accelerate angiogenesis and stimulate leukocyte chemotaxis on burn treatment. In addition, this work suggests that a single-dose LLLT accelerates the inflammatory phase of skin repair.

Antimicrobial photodynamic therapy in the treatment of oral candidiasis in HIV-infected patients.

OBJECTIVE: Antimicrobial photodynamic therapy (aPDT) has been used to combat local infections, and it consists of the combination of a photosensitizer, a light source, and reactive oxygen species (ROS) to kill microbial cells. In this study, we evaluated the effectiveness of aPDT in the treatment of candidiasis in HIV-infected patients. METHODS: Twenty-one patients were divided into three groups. Control group (CG) was treated with the conventional medication for candidiasis (fluconazole 100 mg/day during 14 days). Laser group (LG) was subjected to low-level laser therapy (LLLT), wavelength 660 nm, power of 30 mW, and fluence of 7.5 J/cm(2), in contact with mucosa during 10 sec on the affected point. An aPDT group (aPDTG) was treated with aPDT, that is, combination of a low-power laser and methylene blue 450 µg/mL. Pre-irradiation time was 1 min. Parameters of irradiation were the same ones as for the LG, and patients were single irradiated. Patients were clinically evaluated and culture analysis was performed before, immediately after, and 7, 15, and 30 days after the treatment. RESULTS: Our results showed that fluconazole was effective; however, it did not prevent the return of the candidiasis in short-term. LLLT per se did not show any reduction on Candida spp. aPDT eradicated 100% of the colonies of this fungus and the patients did not show recurrence of candidiasis up to 30 days after the irradiation. CONCLUSIONS: These findings suggest that aPDT is a potential approach to oral candidiasis treatment in HIV-infected patients.

Antimicrobial mechanisms behind photodynamic effect in the presence of hydrogen peroxide.

This study describes the use of methylene blue (MB) plus light (photodynamic inactivation, PDI) in the presence of hydrogen peroxide (H(2)O(2)) to kill Staphylococcus aureus, Escherichia coli, and Candida albicans. When H(2)O(2) was added to MB plus light there was an increased antimicrobial effect, which could be due to a change in the type of ROS generated or increased microbial uptake of MB. To clarify the mechanism, the production of ROS was investigated in the presence and absence of H(2)O(2). It was observed that ROS production was almost inhibited by the presence of H(2)O(2) when cells were not present. In addition, experiments using different sequence combinations of MB and H(2)O(2) were performed and MB optical properties inside the cell were analyzed. Spectroscopy experiments suggested that the amount of MB was higher inside the cells when H(2)O(2) was used before or simultaneously with PDI, and ROS formation inside C. albicans cells confirmed that ROS production is higher in the presence of H(2)O(2). Moreover enzymatic reduction of MB by E. coli during photosensitizer uptake to the photochemically inactive leucoMB could be reversed by the oxidative effects of hydrogen peroxide, increasing ROS formation inside the microorganism. Therefore, the combination of a photosensitizer such as MB and H(2)O(2) is an interesting approach to improve PDI efficiency.

Oral care interventions and oropharyngeal colonization in children receiving mechanical ventilation.

BACKGROUND: Recent progress in identification of oral microorganisms has shown that the oropharynx can be a site of origin for dissemination of pathogenic organisms to distant body sites, such as the lungs. OBJECTIVE: To compare the oropharyngeal microbiological profile, duration of mechanical ventilation, and length of stay in the intensive care unit of children receiving mechanical ventilation who had pharmacological or nonpharmacological oral care. METHODS: A randomized and controlled study was performed in a pediatric intensive unit in São Paulo, Brazil. A total of 56 children were randomly assigned to an experimental group (n=27, 48%) that received oral care with use of 0.12% chlorhexidine digluconate or a control group (n=29, 52%) that received oral care without an antiseptic. Oropharyngeal secretions were collected and cultured on days 0, 2, and 4, and at discharge. RESULTS: The 2 groups had similar demographic characteristics, preexisting underlying diseases, and pharmacological, nutritional, and ventilatory support. Gram-negative bacteria were the predominant pathogens: Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Enter-obacter species. The 2 groups did not differ significantly in the colonization of normal (P= .72) or pathogenic (P= .62) flora, in the duration of mechanical ventilation (P= .67), or in length of stay in the intensive care (P= .22). CONCLUSION: Use of chlorhexidine combined with nonpharmacological oral care did not decrease the colonization profile, duration of mechanical ventilation, or length of stay in critically ill children receiving mechanical ventilation.

Antimicrobial effects of photodynamic therapy on patients with necrotic pulps and periapical lesion.

This study analyzed the antimicrobial effect of photodynamic therapy (PDT) in association with endodontic treatment. Twenty patients were selected. Microbiological samples were taken after accessing the canal, endodontic therapy, and PDT. At the end of the first session, the root canal was filled with Ca(OH)(2), and after 1 week, a second session of the therapies was performed. Endodontic therapy gave a mean reduction of 1.08 log. The combination with PDT significantly enhanced the reduction (1.83 log, p = 0.00002). The second endodontic session gave a similar diminution to the first (1.14 log), and the second PDT was significantly more effective than the first (p = 0.002). The second total reduction was significantly higher than the second endodontic therapy (p = 0.0000005). The total first + second reduction (3.19 log) was significantly different from the first combination (p = 0.00006). Results suggest that the use of PDT added to endodontic treatment leads to an enhanced decrease of bacterial load and may be an appropriate approach for the treatment of oral infections.

Effects of low-power red laser on dentine-pulp interface after cavity preparation. An ultrastructural study.

OBJECTIVE: Studies on the influence of low-power red laser on the repair of dental structures are very scarce. This study investigated the effects of the laser therapy on the ultrastructure of the dentine-pulp interface after conservative class I cavity preparation. DESIGN: Two female volunteers with 8 premolars indicated for extraction for orthodontic reasons were recruited. Class I cavities were prepared and the teeth were randomly divided into two groups. The first group received treatment with a GaA1As laser, lambda=660nm, power of 30mW and energy dose of 2J/cm(2), directly and perpendicularly into the cavity in a single visit. After the irradiation, the cavities were filled with composite resin. The second group received the same treatment, except by the laser therapy. RESULTS: Twenty-eight days post-preparation, the teeth were extracted and processed for transmission electron microscopy analysis. Two sound teeth, without cavity preparation, were also studied. The irradiated group presented odontoblast process in higher contact with the extracellular matrix and the collagen fibrils appeared more aggregated and organised than those of control group. These results were also observed in the healthy teeth. CONCLUSION: These findings suggest that laser irradiation accelerates the recovery of the dental structures involved in the cavity preparation at the predentine region.

Photonic real-time monitoring of bacterial reduction in root canals by genetically engineered bacteria after chemomechanical endodontic therapy.

Microbial infection plays an important role in the development of pulp necrosis and formation of periapical lesions. In vitro and in vivo research in this field, traditionally microbiological culture methods using paper point sampling and quantitative culture, faces difficulties in completely removing bacteria from the root canal system and analyzing sequential procedures. This study employed genetically engineered bioluminescent bacteria and a light-sensitive imaging system to allow real-time visualization of the infection. Ten extracted teeth incubated with P. aeruginosa were treated by mechanical instrumentation with K-files (#30 K-file, #35 K-file and #40 K-file) and chemical irrigation with sodium hypochlorite and hydrogen peroxide. Irrigation alone reduced the contamination in 18%; the first chemomechanical sequence (instrumentation with a #30 K-file + irrigation) provided 41% of reduction; the second sequence (#35 K-file + irrigation) achieved 62%; and the complete therapy (#30 K-file + #35 K-file + #40 K-file + irrigation) achieved 93% of bacterial reduction. These results suggest that the endodontic treatment is dependent on the association of a chemical and mechanical approaches and that root canal enlargement improves bacterial reduction probably because the irrigation has more access to the apical third.

Photonic real-time monitoring of bacterial reduction in root canals by genetically engineered bacteria after chemomechanical endodontic therapy

Microbial infection plays an important role in the development of pulp necrosis and formation of periapical lesions. In vitro and in vivo research in this field, traditionally microbiological culture methods using paper point sampling and quantitative culture, faces difficulties in completely removing bacteria from the root canal system and analyzing sequential procedures. This study employed genetically engineered bioluminescent bacteria and a light-sensitive imaging system to allow real-time visualization of the infection. Ten extracted teeth incubated with P. aeruginosa were treated by mechanical instrumentation with K-files (#30 K-file, #35 K-file and #40 K-file) and chemical irrigation with sodium hypochlorite and hydrogen peroxide. Irrigation alone reduced the contamination in 18 percent; the first chemomechanical sequence (instrumentation with a #30 K-file + irrigation) provided 41 percent of reduction; the second sequence (#35 K-file + irrigation) achieved 62 percent; and the complete therapy (#30 K-file + #35 K-file + #40 K-file + irrigation) achieved 93 percent of bacterial reduction. These results suggest that the endodontic treatment is dependent on the association of a chemical and mechanical approaches and that root canal enlargement improves bacterial reduction probably because the irrigation has more access to the apical third.

Infecções microbianas são um dos fatores principais no desenvolvimento de necrose pulpar e lesões periapicais. Tradicionalmente, estudos in vivo e in vitro utilizam cultura microbiológica com coletas com cones de papel e quantificação de unidades formadoras de colônia. A maior desvantagem deste método é a dificuldade de se remover as bactérias dos canais radiculares e a impossibilidade de promover a análise seqüencial deste procedimento. Este estudo empregou bactérias geneticamente modificadas para apresentarem bioluminescência e um sistema sensível a baixa luminosidade, permitindo a visualização em tempo-real da área infectada. Dez dentes extraídos foram incubados com P. aeruginosa e tratados endodonticamente com instrumentação mecânica com limas K (#30, #35 e #40) e irrigação com hipoclorito de sódio e peróxido de hidrogênio. A irrigação sozinha reduziu a contaminação inicial em 18 por cento; a primeira seqüência de lima e irrigação (lima #30) obteve 41 por cento de redução; a segunda seqüência (lima #35 e irrigação) obteve 62 por cento; e o tratamento completo (lima #30, lima #35, lima #40 e irrigação) reduziu a contaminação bacteriana inicial em 93 por cento. Os resultados sugerem que o tratamento endodôntico é dependente da associação dos procedimentos químico-mecânicos que promovem o alargamento do canal radicular, otimizando a redução microbiana, possivelmente devido ao maior acesso das substâncias químicas à porção apical do canal radicular.