Bimodal multispectral imaging system with cloud-based machine learning algorithm for real-time screening and detection of oral potentially malignant lesions and biopsy guidance.

SIGNIFICANCE: Screening and early detection of oral potentially malignant lesions (OPMLs) are of great significance in reducing the mortality rates associated with head and neck malignancies. Intra-oral multispectral optical imaging of tissues in conjunction with cloud-based machine learning (CBML) can be used to detect oral precancers at the point-of-care (POC) and guide the clinician to the most malignant site for biopsy. AIM: Develop a bimodal multispectral imaging system (BMIS) combining tissue autofluorescence and diffuse reflectance (DR) for mapping changes in oxygenated hemoglobin (HbO2) absorption in the oral mucosa, quantifying tissue abnormalities, and guiding biopsies. APPROACH: The hand-held widefield BMIS consisting of LEDs emitting at 405, 545, 575, and 610 nm, 5MPx monochrome camera, and proprietary Windows-based software was developed for image capture, processing, and analytics. The DR image ratio (R610/R545) was compared with pathologic classification to develop a CBML algorithm for real-time assessment of tissue status at the POC. RESULTS: Sensitivity of 97.5% and specificity of 92.5% were achieved for discrimination of OPML from patient normal in 40 sites, whereas 82% sensitivity and 96.6% specificity were obtained for discrimination of abnormal (OPML + SCC) in 89 sites. Site-specific algorithms derived for buccal mucosa (27 sites) showed improved sensitivity and specificity of 96.3% for discrimination of OPML from normal. CONCLUSIONS: Assessment of oral cancer risk is possible by mapping of HbO2 absorption in tissues, and the BMIS system developed appears to be suitable for biopsy guidance and early detection of oral cancers.

Comparability of Raman Spectroscopic Configurations: A Large Scale Cross-Laboratory Study.

The variable configuration of Raman spectroscopic platforms is one of the major obstacles in establishing Raman spectroscopy as a valuable physicochemical method within real-world scenarios such as clinical diagnostics. For such real world applications like diagnostic classification, the models should ideally be usable to predict data from different setups. Whether it is done by training a rugged model with data from many setups or by a primary-replica strategy where models are developed on a 'primary' setup and the test data are generated on 'replicate' setups, this is only possible if the Raman spectra from different setups are consistent, reproducible, and comparable. However, Raman spectra can be highly sensitive to the measurement conditions, and they change from setup to setup even if the same samples are measured. Although increasingly recognized as an issue, the dependence of the Raman spectra on the instrumental configuration is far from being fully understood and great effort is needed to address the resulting spectral variations and to correct for them. To make the severity of the situation clear, we present a round robin experiment investigating the comparability of 35 Raman spectroscopic devices with different configurations in 15 institutes within seven European countries from the COST (European Cooperation in Science and Technology) action Raman4clinics. The experiment was developed in a fashion that allows various instrumental configurations ranging from highly confocal setups to fibre-optic based systems with different excitation wavelengths. We illustrate the spectral variations caused by the instrumental configurations from the perspectives of peak shifts, intensity variations, peak widths, and noise levels. We conclude this contribution with recommendations that may help to improve the inter-laboratory studies.

Label-free grading and staging of urothelial carcinoma through multimodal fibre-probe spectroscopy.

Urothelial carcinoma (UC) is the most common bladder tumour. Proper treatment requires tumour resection for diagnosing its grade (aggressiveness) and stage (invasiveness). White-light cystoscopy and histopathological examination are the gold standard procedures for clinical and histopathological diagnostics, respectively. However, cystoscopy is limited in terms of specificity, histology requires long tissue processing, both procedures rely on operator's experience. Multimodal optical spectroscopy can provide a powerful tool for detecting, staging and grading bladder tumours in a fast, reliable and label-free modality. In this study, we collected fluorescence, Raman and reflectance spectra from 50 biopsies obtained from 32 patients undergoing transurethral resection of bladder tumour using a multimodal fibre-probe. Principal component analysis allowed distinguishing normal from pathological tissues, as well as discriminating tumour stages and grades. Each individual spectroscopic technique provided high specificity and sensitivity in classifying all tissues; however, a multimodal approach resulted in a considerable increase in diagnostic accuracy (≥95%), which is of paramount importance for tumour grading and staging. The presented method offers the potential for being applied in cystoscopy and for providing an automated diagnosis of UC at the clinical level, with an improvement with respect to current state-of-the-art procedures.

In vitro evaluation of octenidine as an antimicrobial agent against Staphylococcus epidermidis in disinfecting the root canal system

OBJECTIVES: Irrigants are imperative in endodontic therapy for the elimination of pathogens from the infected root canal. The present study compared the antimicrobial efficacy of octenidine dihydrochloride (OCT) with chlorhexidine (CHX) and sodium hypochlorite (NaOCl) against Staphylococcus epidermidis (S. epidermidis) for root canal disinfection. MATERIALS AND METHODS: The minimum inhibitory concentration (MIC) was obtained using serial dilution method. The agar diffusion method was then used to determine the zones of inhibition for each irrigant. Lastly, forty 6-mm dentin blocks were prepared from human mandibular premolars and inoculated with S. epidermidis. Samples were randomly divided into 4 groups of 10 blocks and irrigated for 3 minutes with saline (control), 2% CHX, 3% NaOCl, or 0.1% OCT. Dentin samples were then collected immediately for microbial analysis, including an analysis of colony-forming units (CFUs). RESULTS: The MICs of each tested irrigant were 0.05% for CHX, 0.25% for NaOCl, and 0.0125% for OCT. All tested irrigants showed concentration-dependent increase in zones of inhibition, and 3% NaOCl showed the largest zone of inhibition amongst all tested irrigants (p < 0.05). There were no significant differences among the CFU measurements of 2% CHX, 3% NaOCl, and 0.1% OCT showing complete elimination of S. epidermidis in all samples. CONCLUSIONS: This study showed that OCT was comparable to or even more effective than CHX and NaOCl, demonstrating antimicrobial activity at low concentrations against S. epidermidis.

Multimodal fiber-probe spectroscopy allows detecting epileptogenic focal cortical dysplasia in children.

We evaluated the diagnostic capability of a multimodal spectroscopic approach for classifying normal brain tissue and epileptogenic focal cortical dysplasia in children. We employed fluorescence spectroscopy at two excitation wavelengths (378 nm and 445 nm) and Raman spectroscopy (at 785 nm excitation) for acquiring fluorescence and Raman spectra from 10 normal brains, 16 focal cortical dysplasia specimens and 1 cortical tuber tissue sites using a custom-built multimodal optical point spectroscopic system. We used principal component analysis combined with leave-one-sample-out-cross-validation for tissue classification. The study resulted in 100% sensitivity and 90% specificity using the information obtained from fluorescence at two distinct wavelengths and Raman spectroscopy for discriminating normal brain tissue and focal cortical dysplasia. Our results demonstrate that this methodology has the potential to be applied clinically for the detection of focal cortical dysplasia and can help to improve as precise as possible surgical resection of the dysplastic tissue during surgery for epilepsy. Schematic draw of the experimental setup used for fiber-probe spectroscopy.

Comparative Evaluation of Effect of Nano-hydroxyapatite and 8% Arginine Containing Toothpastes in Managing Dentin Hypersensitivity: Double Blind Randomized Clinical Trial.

PURPOSE: This double blind randomized clinical trial was conducted with the purpose of evaluating the effects of Nano-hydroxyapatite toothpaste as compared to 8% Arginine containing toothpaste in the management of Dentin hypersensitivity (DH). METHOD AND MATERIALS: Patients (30 in each group) suffering from DH and eliciting a VAS score higher than 2 in air blast and tactile test were randomly allocated (block randomization) into either a group 1 (arginine toothpaste) or group 2 (nHA toothpaste). The primary outcome evaluated was the reduction of DH as measured by the electrical stimulus reading on the digital pulp tester. Current required for eliciting a VAS score of 2 was recorded before application of dentifrice. 1 cm of toothpaste was then expressed on the tooth surface for two minutes in each group and rinsed off. The electrical stimulus required to elicit a VAS score of 2 was recorded after 5 minutes, 1 week and 4 weeks. RESULTS: The desensitizing paste containing arginine provided a statistically significant reduction in DH and so did the paste containing nHA. Mean increase in amperage value (reduction in DH) was higher for nHA based than the arginine containing dentifrice. This difference was not statistically significant showing that both toothpastes are equally effective. CONCLUSIONS: The findings of the present study encourage the use of Nano-hydroxyapatite and arginine containing dentifrice as an effective desensitizing agent providing relief from symptoms 5 minutes after application and after 1 and 4 weeks.

Evaluation of the Antibacterial Efficacy of Azadirachta Indica, Commiphora Myrrha, Glycyrrhiza Glabra Against Enterococcus Faecalis using Real Time PCR.

AIM: To compare the antibacterial efficacy of Azadirachta indica (Neem), Commiphora myrrha (Myrrh), Glycyrrhiza glabra (Liquorice) with 2% Chlorhexidine (CHX) against E. faecalis by using Real Time PCR. MATERIALS AND METHODS: A total of fifty teeth specimens (n=50) were inoculated with E. faecalis for 21 days. Specimens were divided into five groups (Group 1: Myrrh, Group 2: Neem, Group 3: Liquorice, Group 4: 2% CHX and Group 5: Saline (negative control)). The intracanal medicaments were packed inside the tooth. After 5 days, the remaining microbial load was determined by using real time PCR. RESULTS: Threshold cycle (Ct) values of Myrrh extract, Neem extract, Liquorice Extract, 2% CHX and saline were found to be 30.94, 23.85, 21.38, 30.93 and 17.8 respectively. CONCLUSION: Myrrh extract showed inhibition of E.faecalis equal to that of 2% CHX followed by Neem, Liquorice and Saline.

Natural Therapeutic Options in Endodontics - A Review.

Complete eradication of microbial biofilms and elimination of the smear layer are the key factors during endodontic treatment. Various chemical irrigants have been proposed in the literature for the same. The major setback with these chemical irrigants is that they are not bio-friendly to the dental and peri-radicular tissues. In the recent years, research to use natural products for root canal disinfection has gained importance. The aim of this article is to compile various herbal products that have been used as an irrigants and intracanal medicaments in the field of Endodontics to eradicate the biofilm and remove smear layer.

Effects of various final irrigants on the shear bond strength of resin-based sealer to dentin.

AIM: This study has been designed to evaluate the effect of strong (MTAD) or soft (1- hydroxyethylidene - 1, 1-bisphosphonate (HEBP) final irrigating solution on the shear bond strength of AH plus sealer to coronal dentin. 17% EDTA was used as the reference. MATERIALS AND METHODS: Forty freshly extracted human maxillary first premolars were prepared using different irrigation protocols (n=10). All the test groups had 1.3% NaOCl as initial rinse and followed by specific final rinse for each group: G1 - distilled water(control), G2 - 17% EDTA, G3- 18% HEBP and G4 - MTAD. Sections of polyethylene tubes that are 3mm long were filled with freshly mixed sealer and placed on the dentin surfaces. The bonding between the sealer and dentine surface was evaluated using shear bond testing. The values were statistically evaluated using one-way ANOVA followed by Tukey's test. RESULT: Significant difference was found among the irrigating regimes. EDTA showed highest bond strength followed by HEBP and MTAD.

Adenosine deaminase in saliva as a diagnostic marker of squamous cell carcinoma of tongue.

Tongue cancer is amongst the most common and fatal types of cancers in the world. The abnormalities in purine metabolism are characteristic features of many human tumors. Little is known about the correlation between the activities of key enzymes of purine nucleotide pathway and clinical indicators of tongue cancer invasiveness and aggressiveness. Fifty patients (M: F 25:25; mean age: 55.6 years (range 45-60; SD 1.8)) with diagnosed squamous cell carcinoma of the tongue (test group) and 30 normal subjects (M: F 15:15) without any systemic disease (control group) were recruited after obtaining informed consent. All patients were staged by the TNM classification. Salivary adenosine deaminase (ADA) activity was assessed in cancerous patients (test group) and normal healthy subjects (control group). Statistically significant differences between test and control groups were observed in salivary ADA (P < 0.001). Furthermore, serum ADA levels significantly increased as the disease stage progressed from stage I to stage III of squamous cell carcinoma of the tongue in both genders (P < 0.001). Salivary ADA might be used as a diagnostic tool for early detection of squamous cell carcinoma of tongue.

Levels of gingival crevicular metalloproteinases-8 and -9 in periodontitis.

Matrix metalloproteinases (MMPs), the key enzymes responsible for matrix degradation, are derived from polymorphonuclear leukocytes during the early stages of periodontitis. The aim of this study was planned to determine the levels of GCF (gingival crevicular fluid) matrix metalloproteinase-8 (MMP-8) and metalloproteinase-9 (MMP-9) patients with periodontitis and in healthy controls. Levels of crevicular MMP-8 and -9 were determined by ELISA in subjects with healthy without any periodontal disease (n = 10) and periodontitis (n = 10). Significantly higher crevicular MMP-8 and -9 were observed in cases of periodontitis compared to healthy adults. Crevicular MMP-8 and -9 may serve as biomarkers of periodontal disease and aid in early detection of periodontitis.

Níveis de metaloproteinases da matriz 8 e 9 na periodontite / Levels of gingival crevicular metalloproteinases-8 and -9 in periodontitis

Objetivo: Determinar os níveis de matriz GCF metaloproteinases 8 (MMP-8) e metaloproteinase 9 (MMP-9) em indivíduos saudáveis e com periodontite.Método: Dez pacientes com doença peridontal e 10 sujeitos saudáveis compuseram a amostra. As análises foram realizadas no Jain Diagnostic Centre, Nova Déli, Índia. O consentimento informado foi obtidos para todos os sujeitos. Níveis presentes no sulco crevicular de MMP-8 e MMP-9 foram determinados por meio do ELISA em ambos os grupos. Dois examinadores analisaram os parâmetros clínicos periodontais e a saliva não estimulada foi coletada. A perda de inserção óssea clínica foi determinada por meio da mensuração dos sítios interproximais.Resultados: Valores significativamente elevador de MMP-* e MMP-9 foram diagnosticados nos portadores de periodontite quando comparado aos indivíduos saudáveis.Conclusão: A presença no fluido crevicular de MMP-8 e MMP-9 servem como biomarcadores da doença periodontal e auxiliam na detecção precoce da periodontite.

Biomarkers of periodontitis in oral fluids.

Matrix metalloproteinases (MMPs), the key enzymes responsible for matrix degradation, are derived from polymorphonuclear leukocytes during the early stages of periodontitis. The present study determined the levels of GCF matrix metalloproteinase-2 (MMP-2) and metalloproteinase-9 (MMP-9) and salivary MMP-8 in patients with gingivitis and periodontitis and in healthy controls. Levels of crevicular MMP-2, MMP-9 and salivary MMP-8 were determined by ELISA in subjects with healthy gingiva (n = 15), gingivitis (n = 18) and periodontitis (n = 20). Significantly higher salivary MMP-8 and crevicular MMP-9 were observed in cases of periodontitis compared to gingivitis and healthy adults. On the other hand, crevicular MMP-2 levels in periodontitis subjects were lower than those in gingivitis and healthy subjects. The three MMP levels were highly correlated to probing depth, and bleeding on probing. Salivary MMP-8, crevicular MMP- 2 and 9 may serve as biomarkers of periodontal disease and aid in early detection of periodontitis or gingivitis.