Real-life practice of reflectance confocal microscopy in France: A prospective multicenter study.

BACKGROUND: Studies demonstrating the potential utility of reflectance confocal microscopy (RCM) have been performed under experimental conditions. OBJECTIVE: To provide an overview of RCM practice in real-life. METHODS: A multicenter, prospective study carried out in 10 university dermatology departments in France. RESULTS: Overall, 410 patients were enrolled. One-half of the patients (48%) were referred by private practice dermatologists. They were referred for diagnosis (84.9%) or presurgical mapping (13%). For diagnosis, the lesions were located on the face (62%), arms and legs (14.9%), and trunk (13.6%), and presurgical mapping was almost exclusively on the face (90.9%). Among those referred for diagnosis, the main indication was suspicion of a skin tumor (92.8%). Of these, 50.6% were spared biopsies after RCM. When RCM indicated surgery, histology revealed malignant lesions in 72.7% of cases. The correlation between RCM and histopathology was high, with a correlation rate of 82.76% and a kappa coefficient of 0.73 (0.63; 0.82). LIMITATIONS: This study was performed in the settings of French tertiary referral hospitals. CONCLUSION: This study shows that in real-life RCM can be integrated into the workflow of a public private network, which enables a less invasive diagnostic procedure for patients.

Corneal Nerve Parameter Reference Values for Chinese Adults Assessed by Corneal Confocal Microscopy.

Background: Confocal corneal microscopy is an excellent new noninvasive tool for assessing diabetic peripheral neuropathy. We aimed to investigate the clinical variables associated with corneal nerve parameters and establish reference values for clinical use in healthy Chinese adults. Methods: The study enlisted 257 healthy volunteers (137 females and 120 males) from two clinical academic centers in China. Two experts captured and selected images of the central corneal subbasal nerve plexus at each center using the same corneal confocal microscopy instrument according to a commonly adopted protocol. Corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), and corneal nerve fiber length (CNFL) were measured using fully automated software (ACCMetrics). The correlation between clinical indicators and confocal corneal microscopy measures was determined using partial correlation. Quantile regression was used to calculate reference values and estimate the effects of clinical factors on the normative values of confocal corneal microscopy measures. Results: Females had significantly higher CNFD, CNBD, and CNFL than males. There was no correlation between age, glycated hemoglobin (HbA1c), height, weight, body mass index (BMI), and any corneal nerve fiber parameter in both sexes. In either sex, age, weight, height, BMI, and HbA1c did not affect the 0.05th quantile values of any corneal nerve parameter. Conclusions: This study establishes sex-adjusted reference values for corneal confocal microscopy measures in Chinese adults and provides a reference for clinical practice and research with this technique.

Three-Dimensional Skin CT Based on Intelligent Algorithm in the Analysis of Skin Lesion Sites Features in Children with Psoriasis.

This research was to explore the application value of three-dimensional computed tomography (CT) based on artificial intelligent algorithm in analyzing the characteristics of skin lesions in children with psoriasis. In this study, 15 children with psoriasis were selected as the observation group, and 15 children with other skin diseases were selected as the control group. The CT images were optimized, and the feature selection was carried out based on artificial intelligent algorithm. Firstly, the results were compared with the results of simple skin three-dimensional CT to determine the effectiveness. Then, the two groups of three-dimensional skin CT image features of skin psoriasis-like hyperplasia, Munro microabscess, dermal papillary vascular dilation, and squamous epithelium based on intelligent algorithms were compared. After comparison, the detection rate of psoriasis-like hyperplasia, Munro microabscess, dermal papillary vascular dilation, and squamous epithelium in the observation group was higher than that in the control group, with significant difference and statistical significance (P < 0.05). In addition, the sensitivity of psoriasis-like hyperplasia, Munro microabscess, dermal papilla vascular dilatation, and squamous epithelium in children with psoriasis was 80.0%, 86.7%, 80.0%, and 93.3%, respectively. The specificity of psoriasis-like hyperplasia, Munro microabscess, dermal papilla vascular dilatation, and squamous epithelium in children with psoriasis was 86.7%, 93.3%, 60.0%, and 73.3%, respectively. The results showed that Munro microabscess and psoriasis-like hyperplasia had high sensitivity and specificity in all diagnostic items, which could be used as important features of skin lesion sites in the diagnosis of psoriasis in children. The research provides a basis for the clinical diagnosis of psoriasis in children, which is worthy of clinical promotion.

Corneal confocal microscopy for the diagnosis of diabetic peripheral neuropathy: A systematic review and meta-analysis.

INTRODUCTION: Corneal confocal microscopy (CCM) is a rapid non-invasive ophthalmic imaging technique that identifies corneal nerve fiber damage. Small studies suggest that CCM could be used to assess patients with diabetic peripheral neuropathy (DPN). AIM: To undertake a systematic review and meta-analysis assessing the diagnostic utility of CCM for sub-clinical DPN (DPN- ) and established DPN (DPN+ ). DATA SOURCES: Databases (PubMed, Embase, Central, ProQuest) were searched for studies using CCM in patients with diabetes up to April 2020. STUDY SELECTION: Studies were included if they reported on at least one CCM parameter in patients with diabetes. DATA EXTRACTION: Corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD), corneal nerve fiber length (CNFL), and inferior whorl length (IWL) were compared between patients with diabetes with and without DPN and controls. Meta-analysis was undertaken using RevMan V.5.3. DATA SYNTHESIS: Thirty-eight studies including ~4,000 participants were included in this meta-analysis. There were significant reductions in CNFD, CNBD, CNFL, and IWL in DPN- vs controls (P < 0.00001), DPN+ vs controls (P < 0.00001), and DPN+ vs DPN- (P < 0.00001). CONCLUSION: This systematic review and meta-analysis shows that CCM detects small nerve fiber loss in subclinical and clinical DPN and concludes that CCM has good diagnostic utility in DPN.

Improving axial resolution in Structured Illumination Microscopy using deep learning.

Structured Illumination Microscopy (SIM) is a widespread methodology to image live and fixed biological structures smaller than the diffraction limits of conventional optical microscopy. Using recent advances in image up-scaling through deep learning models, we demonstrate a method to reconstruct 3D SIM image stacks with twice the axial resolution attainable through conventional SIM reconstructions. We further demonstrate our method is robust to noise and evaluate it against two-point cases and axial gratings. Finally, we discuss potential adaptions of the method to further improve resolution. This article is part of the Theo Murphy meeting issue 'Super-resolution structured illumination microscopy (part 1)'.

Structured illumination microscopy and image scanning microscopy: a review and comparison of imaging properties.

Structured illumination microscopy and image scanning microscopy are two microscopical tech- niques, rapidly increasing in practical application, that can result in improvement in transverse spatial resolution, and/or improvement in axial imaging performance. The history and principles of these techniques are reviewed, and the imaging properties of the two methods compared. This article is part of the Theo Murphy meeting issue 'Super-resolution structured illumination microscopy (part 1)'.

In vivo imaging characterization of basal cell carcinoma and cutaneous response to high-dose ionizing radiation therapy: A prospective study of reflectance confocal microscopy, dermoscopy, and ultrasonography.

BACKGROUND: Radiation therapy (RT) is a treatment option for select skin cancers. The histologic effects of RT on normal skin or skin cancers are not well characterized. Dermoscopy, high-frequency ultrasonography (HFUS), and reflectance confocal microscopy (RCM) are noninvasive imaging modalities that may help characterize RT response. OBJECTIVES: To describe changes in the tumor and surrounding skin of patients with basal cell carcinoma (BCC) treated with RT. METHODS: The study was conducted between 2014 and 2018. Patients with biopsy-proven BCCs were treated with 42 Gy in 6 fractions using a commercially available brachytherapy device. Dermoscopy, HFUS, and RCM were performed before treatment and at 6 weeks, 3 months, and 12 months after RT. RESULTS: A total of 137 imaging assessments (RCM + dermoscopy + HFUS) were performed in 12 patients. BCC-specific features were present in 81.8%, 91%, and 17% of patients imaged with dermoscopy, RCM, and HFUS at baseline, respectively, before treatment. After treatment, the resolution of these features was noted in 33.4%, 91.7%, and 100% of patients imaged with the respective modalities. No recurrences were seen after a mean of 31.7 months of follow-up. LIMITATIONS: Small sample size and no histopathologic correlation. CONCLUSION: Dermoscopy and HFUS were not as reliable as RCM at characterizing BCC RT response.

Optical imaging guided- 'precision' biopsy of skin tumors: a novel approach for targeted sampling and histopathologic correlation.

Dermoscopy and reflectance confocal microscopy (RCM) are two noninvasive, optical imaging tools used to facilitate clinical diagnosis. A biopsy technique that produces exact correlation with optical imaging features is not previously reported. To evaluate the applications of a novel feature-focused 'precision biopsy' technique that correlates clinical-dermoscopy-RCM findings with histopathology. This was a prospective case-series performed during August 2017 and June 2019 at a tertiary care cancer. We included consecutive patients requiring a precise dermoscopy-RCM-histopathologic correlation. We performed prebiopsy dermoscopy and both wide probe and handheld RCM of suspicious lesions. Features of interest were isolated with the aid of paper rings and a 2 mm punch biopsy was performed in the dermoscopy- or RCM-highlighted area. Tissue was processed either en face or with vertical sections. One-to-one correlation with histopathology was obtained. Twenty-three patients with 24 lesions were included in the study. The mean age was 64.6 years (range 22-91 years); there were 16 (69.6%) males, 14 (58.3%) lesions biopsied were on head and neck region. We achieved tissue-conservation diagnosis in 100% (24/24), 13 (54.2%) were clinically equivocal lesions, six (25%) were selected for 'feature correlation' of structures on dermoscopy or RCM, and five (20.8%) for 'correlation of new/unknown' RCM features seen on follow-up. The precision biopsy technique described herein is a novel method that facilitates direct histopathological correlation of dermoscopy and RCM features. With the aids of optical imaging devices, accurate diagnosis may be achieved by minimally invasive tissue extraction.

Dark pigmented lesions: Diagnostic accuracy of dermoscopy and reflectance confocal microscopy in a tertiary referral center for skin cancer diagnosis.

BACKGROUND: There is lack of studies on the diagnostic accuracy of dermoscopy and reflectance confocal microscopy (RCM) for dark pigmented lesions. OBJECTIVE: To assess the diagnostic accuracy of dermoscopy plus confocal microscopy for melanoma diagnosis of dark pigmented lesions in real life. METHODS: Prospective analysis of difficult dark lesions with clinical/dermoscopic suspicion of melanoma referred for RCM for further analysis. The outcome could be excision or dermoscopic digital follow-up. RESULTS: We included 370 clinically dark lesions from 350 patients (median age, 45 y). Because of the clinical/dermoscopic/RCM approach, we saved 129 of 213 unnecessary biopsies (specificity of 60.6%), with a sensitivity of 98.1% (154/157). The number needed to excise with the addition of RCM was 1.5 for melanoma diagnosis. LIMITATIONS: Single institution based; Italian population only. CONCLUSIONS: This study showed that RCM coupled with dermoscopy increases the specificity for diagnosing melanoma, and it helps correctly identify benign lesions. Our findings provide the basis for subsequent prospective studies on melanocytic neoplasms belonging to patients in different countries.

Atypical cells on reflectance confocal microscopy may not represent melanoma: A case of axillary pigmented extramammary Paget disease.

Pigmented extramammary Paget disease (PEMPD) is a rare intraepithelial carcinoma which can clinically resemble other pigmented neoplasms. Similarities to melanoma on dermoscopy, histopathology, and reflectance confocal microscopy (RCM) increase the risk of misdiagnosis and, consequently, mismanagement. Here, we describe a case of a 67-year-old African American woman with a large, pigmented axillary patch that exhibited features of melanoma on RCM, guiding the clinician to perform an excisional biopsy. While traditional histopathology resembled melanoma, immunohistochemistry staining was performed and revealed PEMPD. We highlight an uncommon clinical presentation of PEMPD disease and identify morphologic mimickers of melanoma on RCM-as well as differentiating features.

Real-time Lissajous imaging with a low-voltage 2-axis MEMS scanner based on electrothermal actuation.

Laser scanning based on Micro-Electro-Mechanical Systems (MEMS) scanners has become very attractive for biomedical endoscopic imaging, such as confocal microscopy or Optical Coherence Tomography (OCT). These scanners are required to be fast to achieve real-time image reconstruction while working at low actuation voltage to comply with medical standards. In this context, we report a 2-axis Micro-Electro-Mechanical Systems (MEMS) electrothermal micro-scannercapable of imaging large fields of view at high frame rates, e.g. from 10 to 80 frames per second. For this purpose, Lissajous scan parameters are chosen to provide the optimal image quality within the scanner capabilities and the sampling rate limit, resulting from the limited A-scan rate of typical swept-sources used for OCT. Images of 233 px × 203 px and 53 px × 53 px at 10 fps and 61 fps, respectively, are experimentally obtained and demonstrate the potential of this micro-scannerfor high definition and high frame rate endoscopic Lissajous imaging.

Probe-based confocal laser endomicroscopy versus biopsies in the diagnostics of oesophageal and gastric lesions: A prospective, pathologist-blinded study.

BACKGROUND AND AIM: Probe-based confocal laser endomicroscopy (pCLE) provides real-time microscopic visualisation. Our aim was to compare the diagnostic accuracy of pCLE with standard biopsies in patients with visible oesophageal or gastric lesions. METHODS: This was a single-centre, prospective, pathologist-blinded study. Patients underwent high-resolution endoscopy, and lesions were examined by pCLE followed by standard biopsies. A definitive diagnosis was determined from resection specimen. Main outcomes were overall diagnostic accuracy, sensitivity, specificity and positive and negative predictive values. RESULTS: We examined 74 lesions in 67 patients. Definitive diagnoses revealed 34 malignant and 40 non-malignant lesions. pCLE diagnosis was correct in 89.2% (66/74), while diagnosis based on biopsy was correct in 85% (57/67; p = 0.6). The overall diagnostic accuracy of biopsies was 85% (76-94%) and that of pCLE was 89% (79-96%). pCLE correctly diagnosed malignant lesions, comprising oesophageal adenocarcinoma, oesophageal squamous-cell cancer or gastric adenocarcinoma, in 88.2% (30/34) of cases, while biopsy was correctly diagnosed in 75.9% (22/29; p = 0.3). Sensitivity and specificity to diagnose a malignant lesion were 75.9% (95% confidence interval (CI) 56-89%) and 100% (95% CI 90-100%) for biopsies and 88.2% (95% CI 72-97%) and 92% (95% CI 79-98%) for pCLE. No differences between biopsies and pCLE were found with regard to sensitivity, specificity to diagnose dysplastic and benign lesions (p > 0.2). CONCLUSION: pCLE provides satisfactory diagnostic accuracy comparable with standard biopsies in patients with oesophageal or gastric lesions. ClinicalTrials.gov identifier: NCT0292049).

Impact of needle-based confocal laser endomicroscopy on the therapeutic management of single pancreatic cystic lesions.

BACKGROUND AND AIM: The diagnosis and therapeutic management of large single pancreatic cystic lesions (PCLs) represent major issues for clinicians and essentially rely on endoscopic ultrasound fine-needle aspiration (EUS-FNA) findings. Needle-based confocal laser endomicroscopy (nCLE) has high diagnostic performance for PCLs. This study aimed to evaluate the impact of nCLE on the therapeutic management of patients with single PCLs. METHODS: Retrospective and comparative study. Five independent pancreatic disease experts from tertiary hospitals independently reviewed data from a prospective database of 206 patients with single PCL, larger than 2 cm and who underwent EUS-FNA and nCLE. Two evaluations were performed. The first one included the sequential review of clinical information, EUS report and FNA results. The second one included the same data + nCLE report. Participants had to propose a therapeutic management for each case. RESULTS: The addition of nCLE to EUS-FNA led to significant changes in therapeutic management for 28% of the patients (p < 0.001). nCLE significantly increased the interobserver agreement of 0.28 (p < 0.0001), from 0.36 (CI 95% 0.33-0.49) to 0.64 (CI 95% 0.61-0.67). nCLE improved the rates of full agreement among the five experts of 24% (p < 0.0001), from 30 to 54%. With nCLE, the surveillance rate of benign SCAs fell by 35%, from 40 (28/70) to 5% (4/76). CONCLUSION: The addition of nCLE to EUS-FNA significantly improves reliability of PCL diagnosis and could impact the therapeutic management of patients with single PCLs. ClinicalTrials.gov number, NCT01563133.

A study on confocal endomicroscopy in comparison with histopathology for polypoidal lesions of the gastrointestinal tract: A prospective single-centre experience.

BACKGROUND: Confocal laser endomicroscopy (CLE) has a potential to make optical diagnosis of neoplastic polypoidal lesions and may replace traditional histology in the proposed "diagnose and discard approach". The present study was planned to assess the accuracy of probe-based CLE in predicting histology of polypoidal lesions of gastrointestinal (GI) tract in vivo before their removal. METHODS: In this prospective single-centre study, patients with upper and/or lower GI polypoidal lesions were enrolled. After detection of polypoidal lesions with white light endoscopy, probe-based CLE examination was performed. Real-time and offline presumptive CLE diagnosis of polypoidal lesions was made as per Miami classification and was compared with histopathology as the gold standard. RESULTS: A total of 50 GI polyps from 50 patients (28 males) were assessed. The mean (±SD) size of polyps was 13.7 (± 8.5) mm. Most polyps were located at the cecum (24.0%) or stomach (24.0%). On histological examination, hyperplastic and adenomatous polyps, adenocarcinoma, and lipoma were seen in 54%, 26%, 18% and 2% patients, respectively. On comparison of real-time CLE examination with histopathology, 40 (83.3%) and 8 patients (16.7%) had concordant and discordant results, respectively. Two polyps were inconclusively diagnosed on CLE. On offline examination, concordance with histopathology was observed in 85.4% (n = 41) of polyps, which was marginally better than online examination, though the difference was not statistically significant (p = 0.45). On comparing the real-time and offline findings of CLE, concordance was found in 91.7% of the cases. Accuracy, sensitivity, specificity, positive and negative predictive values on real-time evaluation were 83.3%, 87.5%, 79.1%, 80.7%, and 86.3%, respectively. CONCLUSION: CLE is a useful tool for prediction of histology to assess the polypoidal lesions of the GI tract, and it may avoid polypectomy at least in some patients.

Probe-based confocal laser endomicroscopy for diagnosis of nasopharyngeal carcinoma in vivo.

OBJECTIVES/HYPOTHESIS: Probe-based confocal laser endomicroscopy (pCLE) is a novel technique allowing real-time evaluation of the histological features of tissues in vivo at the cellular level. This study aimed to evaluate the feasibility of using pCLE in the diagnosis of nasopharyngeal carcinoma (NPC). STUDY DESIGN: Feasibility study. METHODS: In this study, the pCLE images of the lesions, as well as the surrounding or contralateral normal mucosa of the lesions, were acquired in vivo from each patient after intravenous injecting of 2.5 mL fluorescein. Biopsy specimens were collected at the imaged sites followed by a histopathological diagnosis by the pathologists, which was used as the gold standard. The pCLE images were compared to histopathological diagnosis of visualized sites by using sensitivity, specificity, negative predictive value (NPV), and positive predictive value (PPV). RESULTS: Diagnoses based on pCLE images correlated well with the gold standard diagnoses based on tissue histology. The overall sensitivity, specificity, PPV, and NPV for diagnosis of carcinoma versus nondysplasia were 93.8% (67.7%-99.7%), 90.5% (68.2%-98.3%), 88.2% (62.3%-97.9%), and 95.0% (73.1%-99.7%), respectively, and the four indices for pCLE diagnosis of dysplasia versus nondysplasia were 60.0% (17.0%-92.7%), 80.9% (57.4%-93.7%), 42.9% (11.8%-79.8%), and 89.5% (65.5%-98.2%), respectively. The overall sensitivity for diagnosis of carcinoma versus dysplasia was 93.8% (67.7%-99.7%), specificity was 40% (7.3%-83.0%), PPV was 83.3% (57.7%-95.6%), and the NPV was 66.7% (12.5%-98.2%). CONCLUSIONS: CLE is a suitable and valid method for otolaryngologists to diagnose of NPC in vivo. LEVEL OF EVIDENCE: NA Laryngoscope, 129:897-902, 2019.

Endocytoscopic classification can be predictive for relapse in ulcerative colitis.

The present study was conducted to explore the association of endocytoscopy (EC) classification with microscopic inflammatory features of ulcerative colitis (UC) and disease relapse.EC was performed for mild-to-moderate UC 32 cases from January 2010 to August 2016. EC appearance was stratified into 4 categories: EC-A, regular arrangement of round to oval pits; EC-B, irregular arrangement with/without enlarged spaces between regular pits; EC-C, deformed pits with distorted crypt lumen which are unordered in arrangement but not disrupted; and EC-D, disruptive or disappeared pits. We evaluated the association of EC classification with Mayo endoscopic subscores (MES) and the clinically active state. Microscopic features including the severity in mucosal inflammatory infiltrates the presence of crypt abscess and goblet cell depletion were assessed by an experienced pathologist who was blinded to clinical and endoscopic information. Clinical follow-up was provided for treating 22 UC patients more than 60 months after EC.There were 15 cases in EC-A, 8 in EC-B, 5 in EC-C, and 4 in EC-D. Interobserver agreement was excellent with κ value of 0.77. There were 13 patients in active disease stage, while 19 in remission. Each EC-A case was in clinically remission stage, while all the EC-C and EC-D cases were in the active stage. There were 4 and 4 EC-B cases in remission and active stage, respectively. The EC-A group consisted of 11 MES0 and 4 MES1 cases, whereas the EC-B group consisted of 2 MES0 and 6 MES1 cases. There were no cases of MES0 in the EC-C and -D groups. The EC stratification was significantly associated with pathognomonic microscopic features for UC. There were significant differences in the remission rate among the EC groups. None had relapse in the EC-A group during the follow-up period.EC stratification could be predictive for relapse in UC. Moreover, EC is reliable to assess UC specific microscopic features.

Single Pair Förster Resonance Energy Transfer: A Versatile Tool To Investigate Protein Conformational Dynamics.

Conformational changes of proteins and other biomolecules play a fundamental role in their functional mechanism. Single pair Förster resonance energy transfer (spFRET) offers the possibility to detect these conformational changes and dynamics, and to characterize their underlying kinetics. Using spFRET on microscopes with different modes of detection, dynamic timescales ranging from nanoseconds to seconds can be quantified. Confocal microscopy can be used as a means to analyze dynamics in the range of nanoseconds to milliseconds, while total internal reflection fluorescence (TIRF) microscopy offers information about conformational changes on timescales of milliseconds to seconds. While the existence of dynamics can be directly inferred from the FRET efficiency time trace or the correlation of FRET efficiency and fluorescence lifetime, additional computational approaches are required to extract the kinetic rates of these dynamics, a short overview of which is given in this review.

Síndrome iridocorneoendotelial: variedad Chandler / Iridocorneal endothelial syndrome in Chandler variety

En el síndrome iridocorneoendotelial se unifican diferentes variaciones clínicas de una misma entidad. El denominador común de todas ellas es una peculiar anormalidad de las células endoteliales, alteraciones del iris y el desarrollo de glaucoma, generalmente unilateral y más común en mujeres. Se presenta un caso clínico de la variedad Chandler, quien acudió a la consulta de catarata, con este diagnóstico en el ojo derecho. Se realiza cirugía de catarata en ambos ojos con excelentes resultados y control de la presión intraocular(AU)

Iridocorneal endothelial syndrome comprises different clinical variations of the same disease. The common features of all them are peculiar anomaly of the endothelial cells, alterations of the iris and the onset of glaucoma, generally unilateral and more common in women. A clinical case of the Chandler variety is presented, which is a woman with cataract, and iridocorneal endothelial syndrome diagnosis on the right eye. Cataract surgery was performed in both eyes with excellent results and control of the intraocular pressure(AU)

Influência de substâncias irrigadoras em gel sobre o biofilme microbiano / Influence of gel irrigant agents in oral biofilm

Objetivo: o objetivo do presente estudo foi avaliar a ação antimicrobiana do hipoclorito de sódio a 1%, da clorexidina a 2% e do EDTA a 24% ­ todos na forma de gel ­, sobre o biofilme oral. Métodos: blocos de dentina bovina estéreis foram inseridos em um dispositivo intrabucal, o qual foi utilizado por um voluntário durante 3 dias. Após a formação do biofilme, os blocos foram imersos em 100 µl das diferentes substâncias avaliadas, durante 5 minutos. Após o tratamento, as amostras foram coradas com 50 µl de uma solução com iodeto de propídio e SYTO 9, e avaliadas em um microscópio confocal imediatamente após a remoção do agente antimicrobiano, gerando um total de 50 imagens por grupo. Os dados foram analisados por meio dos testes de Kruskal-Wallis e Dunn (α = 0,05). Resultados: diferenças estatísticas entre os grupos experimentais e controle foram observadas. O hipoclorito de sódio a 1% foi mais eficaz do que as outras substâncias avaliadas (p < 0,05). Ainda, a clorexidina a 2% reduziu a porcentagem de células vivas de forma mais significativa, comparada ao EDTA (p < 0,05). Conclusões: os agentes irrigantes utilizados nesse estudo não apresentaram capacidade de dissolução do biofilme formado in situ. No entanto, o hipoclorito de sódio apresentou melhores resultados, quanto comparado à clorexidina e ao EDTA.