Unintended subdural anesthesia and subdural air bubbles after attempted epidural anesthesia in a patient undergoing cesarean section.

BACKGROUND: Unintended subdural anesthesia accompanied by air bubbles compressing the cauda after attempting epidural anesthesia is rare. CASES: A 41-year-old pregnant woman was scheduled to undergo epidural anesthesia for cesarean section. After attempting epidural anesthesia, she experienced prolonged hypotension and recovery time, especially in the right extremity. Through magnetic resonance imaging we found subdural air bubbles compressing the right side of the cauda equina in the L3 region. Thus, we considered unintended subdural anesthesia and performed conservative management with close observation. Her symptoms completely resolved within 24 h. CONCLUSIONS: Here, we report a case with various features of subdural anesthesia and subdural air bubbles compressing the cauda.

Proximity-Induced Tunable Magnetic Order at the Interface of All-van der Waals-Layered Heterostructures.

Spin-orbit coupling (SOC) plays a crucial role in controlling the spin-charge conversion efficiency, spin torque, and complex magnetic spin structures. In this study, we investigate the interplay between SOC and ferromagnetism in heterostructures of large-SOC and magnetic materials. We highlight the importance of the SOC-proximity effect on magnetic ordering in all-van der Waals-layered heterostructures, specifically Fe3GeTe2(FGT)/monolayer W1-xVxSe2 (x = 0 and 0.05). By increasing the SOC strength, we demonstrate various magnetic orderings induced at the interface of the heterostructure, including spin-flop, spin-flip, and inverted magnetization. Moreover, we show a sharp magnetic switching from antiferromagnetic state to ferromagnetic state in FGT/W0.95V0.05Se2, which is characteristic of the synthetic antiferromagnetic structure. This proof-of-concept result offers the possibility of interface-tailoring spintronics, including two-dimensional magnetoresistive random access memory toggle switching. Our findings provide insight into the design and development of next-generation spintronic devices by exploiting the interplay between SOC and magnetic ordering in all-van der Waals-layered heterostructures.

Apigenin attenuates tetrabromobisphenol A-induced cytotoxicity in neuronal SK-N-MC cells.

Tetrabromobisphenol A (TBBPA) is a reactive brominated flame retardant widely used in various industrial and household products. This compound is persistent in the environment and accumulates in living organisms through the food chain, and is toxic to animals and human beings. Studies have shown that TBBPA is toxic to various human cell lines, including neuronal cells. Apigenin is a dietary flavonoid that exhibits various beneficial health effects on biological activities, including antioxidant, anti-inflammatory, and neuroprotective effects. This study investigated the cytoprotective effects of apigenin against TBBPA-mediated cytotoxicity in SK-N-MC cells. Our results demonstrated that treatment of SK-N-MC cells with apigenin increased the cell viability, which was decreased by TBBPA, and reduced apoptosis and autophagy induced by TBBPA. Although we did not observe any change in the levels of IL-1ß and nitrite in cultured cells after TBBPA treatment, apigenin was found to decrease the production of these pro-inflammatory mediators. Apigenin decreased the intracellular Ca2+ concentration, NOX4 level, oxidative stress, and mitochondrial membrane potential loss and increased the mitochondrial biogenesis and nuclear Nrf2 levels that were reduced by TBBPA. Finally, apigenin treatment decreased Akt and ERK induction in cells exposed to TBBPA. Based on these results, apigenin could be a promising candidate for designing natural drugs to treat or prevent TBBPA-related neurological disorders.

Characterization of an Entner-Doudoroff pathway-activated Escherichia coli.

BACKGROUND: Escherichia coli have both the Embden-Meyerhof-Parnas pathway (EMPP) and Entner-Doudoroff pathway (EDP) for glucose breakdown, while the EDP primarily remains inactive for glucose metabolism. However, EDP is a more favorable route than EMPP for the production of certain products. RESULTS: EDP was activated by deleting the pfkAB genes in conjunction with subsequent adaptive laboratory evolution (ALE). The evolved strains acquired mutations in transcriptional regulatory genes for glycolytic process (crp, galR, and gntR) and in glycolysis-related genes (gnd, ptsG, and talB). The genotypic, transcriptomic and phenotypic analyses of those mutations deepen our understanding of their beneficial effects on cellulosic biomass bio-conversion. On top of these scientific understandings, we further engineered the strain to produce higher level of lycopene and 3-hydroxypropionic acid. CONCLUSIONS: These results indicate that the E. coli strain has innate capability to use EDP in lieu of EMPP for glucose metabolism, and this versatility can be harnessed to further engineer E. coli for specific biotechnological applications.

Learning outcomes of a mobile application for dental infection control education.

PURPOSE/OBJECTIVES: This study aimed to apply and verify the effectiveness of a mobile-based dental infection control education application to enable students majoring in dental hygiene to learning dental infection control education without time and space constraints. METHODS: This study used a nonequivalent control group pretest-posttest design to examine differences in learning outcomes between an experimental group that learned through the mobile application and a control group that learned with handouts. The Infection Prevention and Control Mobile Application (IPC App) and handouts were developed by referring to the Center for Disease Control's (CDC) guidelines for Infection Prevention and Control in Dental Settings. Both the experimental and control groups were guided to perform self-regulated learning, where they independently led and managed their learning for two weeks. The study was conducted at the D university college with 42 students from the second grade in the Department of Dental Hygiene from August to October 2021. Differences in knowledge, self-efficacy, and summative evaluation were analyzed using an independent sample t-test and repeated measures analysis of variance (p < 0.05). RESULTS: The findings confirmed that the experimental group who learned through the IPC mobile application had improved their knowledge and indicated a higher summative evaluation than the control group that learned via learning documents (p < 0.05). CONCLUSIONS: Owing to the high accessibility and repeatability of the learning content, the mobile application recommended in this study may serve as an effective self-directed learning tool for students to gain knowledge on the standard precautions for dental infection control.

Emergent Multifunctional Magnetic Proximity in van der Waals Layered Heterostructures.

Proximity effect, which is the coupling between distinct order parameters across interfaces of heterostructures, has attracted immense interest owing to the customizable multifunctionalities of diverse 3D materials. This facilitates various physical phenomena, such as spin order, charge transfer, spin torque, spin density wave, spin current, skyrmions, and Majorana fermions. These exotic physics play important roles for future spintronic applications. Nevertheless, several fundamental challenges remain for effective applications: unavoidable disorder and lattice mismatch limits in the growth process, short characteristic length of proximity, magnetic fluctuation in ultrathin films, and relatively weak spin-orbit coupling (SOC). Meanwhile, the extensive library of atomically thin, 2D van der Waals (vdW) layered materials, with unique characteristics such as strong SOC, magnetic anisotropy, and ultraclean surfaces, offers many opportunities to tailor versatile and more effective functionalities through proximity effects. Here, this paper focuses on magnetic proximity, i.e., proximitized magnetism and reviews the engineering of magnetism-related functionalities in 2D vdW layered heterostructures for next-generation electronic and spintronic devices. The essential factors of magnetism and interfacial engineering induced by magnetic layers are studied. The current limitations and future challenges associated with magnetic proximity-related physics phenomena in 2D heterostructures are further discussed.

Protective effects of sciadopitysin against methylglyoxal-induced degeneration in neuronal SK-N-MC cells.

The accumulation of advanced glycation end products (AGEs) causes metabolic dysfunction and neuronal cell damage. Methylglyoxal (MG) is a major glycating agent that reacts with basic residues present in proteins and promotes the formation of AGEs. Sciadopitysin, a type of biflavonoid, exerts protective effects against neuronal cell damage; however, the underlying mechanisms have not been studied. This study aimed to investigate the mechanisms underlying the protective effects of sciadopitysin against MG-mediated cytotoxicity in SK-N-MC neuroblastoma cells. Our results demonstrated that pretreatment of SK-N-MC cells with sciadopitysin improved the cell viability that was inhibited by MG and inhibited the apoptosis induced by MG. Sciadopitysin attenuated intracellular Ca2+ , NOX4 levels, oxidative stress, and MG-protein adduct levels, and increased nuclear Nrf2 and glyoxalase 1 levels in the presence of MG. These results suggest that sciadopitysin exerts neuroprotective effects against MG-induced death of human SK-N-MC cells via its antioxidative action. This study highlights sciadopitysin as a promising candidate for antioxidant therapy and designing natural drugs against AGE-induced neurodegenerative disorders.

The influence of positive end-expiratory pressure (PEEP) in predicting fluid responsiveness in patients undergoing one-lung ventilation.

Background: Dynamic preload parameters such as pulse pressure variation (PPV) and stroke volume variation (SVV) have widely been used as accurate predictors for fluid responsiveness in patients under mechanical ventilation. To circumvent the limitation of decreased cyclic change of intrathoracic pressure, we performed an intermittent PEEP challenge test to evaluate whether PPV or SVV can predict fluid responsiveness during one-lung ventilation (OLV). Methods: Forty patients undergoing OLV were analyzed. Baseline hemodynamic variables including PPV and SVV and respiratory variables were recorded after chest opening in lateral position under OLV (T1). Five minutes after application of PEEP 10 cmH2O, the parameters were recorded (T2). Thereafter, PEEP was withdrawn to 0 cmH2O for 5 minutes (T3), and fluid loading was performed with balanced crystalloid solution 6 mL/kg of ideal body weight for 5 minutes. Five minutes after completion of fluid loading, all variables were recorded (T4). The patient was classified as fluid responder if SV increased ≥10% after fluid loading and as non-responder if SV increased <10%. Results: Prediction of fluid responsiveness was evaluated with area under the receiver operating characteristic (ROC) curve (AUC). Change in stroke volume variation (ΔSVV) showed AUC of 0.9 (P < 0.001), 95% CI = 0.82-0.99, sensitivity = 88%, specificity = 82% for discrimination of fluid responsiveness. Change in pulse pressure variation (ΔPPV) showed AUC of 0.88 (P < 0.001), 95% CI = 0.78-0.97, sensitivity = 83%, specificity = 72% in predictability of fluid responsiveness. Cardiac index and stroke volume were well maintained after PEEP challenge in non-responders while they increased in responders. Conclusions: ΔPPV and ΔSVV induced by PEEP challenge are reliable parameters to predict fluid responsiveness as well as very good predictors of fluid unresponsiveness during OLV.

Oleuropein attenuates the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-perturbing effects on pancreatic ß-cells.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an endocrine disrupting compound and persistent organic pollutant that has been associated with diabetes in several epidemiological studies. Oleuropein, a major phenolic compound in olive fruit, is a superior antioxidant and radical scavenger. This study aimed to examine the effects of oleuropein against TCDD-induced stress response in a pancreatic beta cell line, INS-1 cells. Cells were pre-incubated with various concentrations of oleuropein and then stimulated with TCDD (10 nM) for 48 hrs. When treated with TCDD, INS-1 cells produced robust amounts of prostaglandin E2 (PGE2) compared to the untreated control, and this increase was inhibited by oleuropein treatment. TCDD increased Ca2+-independent phospholipase A2 (iPLA2ß) level, but had no effect on Group 10 secretory phospholipase A2 (PLA2G10) level, while oleuropein deceased the levels of iPLA2ß and PLA2G10 in the presence of TCDD. Cyclooxygenase-1 (COX-1) was significantly increased by TCDD treatment and attenuated with oleuropein pretreatment. Oleuropein decreased TCDD-mediated production of JNK, TNF-α, and ROS. In addition, oleuropein increased Akt and GLUT2 levels suppressed by TCDD in INS-1 cells. Thus, the results suggest that oleuropein prevents pancreatic beta cell impairment by TCDD.

Changes in dental hygiene students' working posture following digital sound feedback.

INTRODUCTION: This study aimed to observe changes in working posture by measuring the REBA (Rapid Entire Body Assessment) score of dental hygiene students according to digital sound feedback linked with a smartphone application. METHODS: This study was conducted on 28 fourth-year dental hygiene students who received theoretical and practical training on dental posture in the second year and then practised on mannequins and patients for about four semesters. Periodontal instrumentation was performed freely by applying digital sound notification feedback for four weeks after baseline, 30 minutes per week. REBA was measured after performing periodic structure construction without providing digital sound notification feedback for the last 1-2 minutes. Follow-up was conducted the same way 2-3 weeks after the intervention period. RESULTS: The REBA score for total, neck and trunk of all subjects showed statistically significant decreases post-intervention compared with the baseline scores (total p < .001, neck p < .001 and trunk p = .042). CONCLUSIONS: A digital sound feedback system was shown to be effective in encouraging correct working posture in dental hygiene students by helping them improve their REBA scores.

Efficacy of mobile health care in patients undergoing fixed orthodontic treatment: A systematic review.

OBJECTIVES: We performed a systematic review of studies that assessed the efficacy of mobile health care in patients undergoing fixed orthodontic treatment, in an attempt to obtain contemporary evidence on the clinical impact of mobile health care on the patients' oral health and orthodontic treatment outcomes. METHODS: A systematic literature search was conducted using the PRISMA guidelines. We performed a comprehensive search using multiple databases (Cochrane Library, MEDLINE, EMBASE, Scopus, Google Scholar and Web of Science) with no restrictions on the language of publication or publication status up until 23 April 2019 to identify eligible studies. RESULTS: We included 11 unique studies. In this review, 9 of the 11 selected studies showed positive effects of mobile healthcare intervention, which resulted in reduced scores of oral hygiene and periodontal indices and white-spot lesions, as well as decreased duration of treatment, sagittal distance and intensity of self-reported pain. CONCLUSIONS: Mobile health care can be utilized as an adjuvant intervention to improve treatment outcomes in patients undergoing fixed orthodontic treatment. Oral healthcare experts should consider novel interventions using mobile devices in addition to the conventional mode of intervention.

Efficacy of intermittent epidural dexamethasone bolus for zoster-associated pain beyond the acute phase.

Herpes zoster develops when latent varicella zoster virus is reactivated in the trigeminal or dorsal root ganglions. Zoster-associated pain (ZAP) is neuropathic pain caused by the herpes zoster virus. Histological studies of postherpetic neuralgia patients suggest that inflammation is involved in ZAP. The effectiveness of local anesthetic and steroid epidural injections in ZAP patients has been reported. However, most studies included patients with acute herpes zoster, and the safety and therapeutic effects of different doses of epidural steroids in ZAP patients remain elusive. In this study, we randomly assigned 42 patients with severe ZAP beyond the acute phase, as determined by a numeric rating scale (NRS) score ≥7, to receive continuous epidural infusion of local anesthetics with either a one-time 5-mg dose or intermittent repeated doses (15 mg total) of dexamethasone. We found that intermittent repeated epidural dexamethasone bolus resulted in reduced NRS scores and an increased likelihood of complete remission in ZAP patients without any adverse effects. Thus, our results suggest that intermittent repeated epidural dexamethasone administration is safe and effective for treatment of ZAP beyond the acute phase.

Nanoengineering room temperature ferroelectricity into orthorhombic SmMnO3 films.

Orthorhombic RMnO3 (R = rare-earth cation) compounds are type-II multiferroics induced by inversion-symmetry-breaking of spin order. They hold promise for magneto-electric devices. However, no spontaneous room-temperature ferroic property has been observed to date in orthorhombic RMnO3. Here, using 3D straining in nanocomposite films of (SmMnO3)0.5((Bi,Sm)2O3)0.5, we demonstrate room temperature ferroelectricity and ferromagnetism with TC,FM ~ 90 K, matching exactly with theoretical predictions for the induced strain levels. Large in-plane compressive and out-of-plane tensile strains (-3.6% and +4.9%, respectively) were induced by the stiff (Bi,Sm)2O3 nanopillars embedded. The room temperature electric polarization is comparable to other spin-driven ferroelectric RMnO3 films. Also, while bulk SmMnO3 is antiferromagnetic, ferromagnetism was induced in the composite films. The Mn-O bond angles and lengths determined from density functional theory explain the origin of the ferroelectricity, i.e. modification of the exchange coupling. Our structural tuning method gives a route to designing multiferroics.

Achieving ferromagnetic insulating properties in La0.9Ba0.1MnO3 thin films through nanoengineering.

Strongly correlated manganites have a wide range of fascinating magnetic and electronic properties, one example being the coexistence of ferromagnetic and insulating properties in lightly-doped bulk. However, it is difficult to translate bulk properties to films. Here, this problem is overcome by thin film nanoengineering of the test case system, La0.9Ba0.1MnO3 (LBMO). This was achieved by using vertically aligned nanocomposite (VAN) thin films of LBMO + CeO2 in which CeO2 nanocolumns form embedded in a LBMO matrix. The CeO2 columns produce uniform tensile straining of the LBMO. Also light Ce doping of intrinsic cation vacancies in the LBMO occurs. Together, these factors strongly reduced the double exchange coupling and metallicity. Hence, while standard plain reference films showed an insulator-to-metal transition at >200 K, originating from defects and complex structural relaxation, the VAN LBMO films exhibited ferromagnetic insulating properties (while maintaining a Tc of 188 K). This is the first time that a combined strain + doping method is used in a VAN system to realise exemplary properties which cannot be realised in plain films. This work represents an important step in engineering high performance spintronic and multiferroic thin film devices.

Orientin reduces the inhibitory effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on adipogenic differentiation and insulin signaling pathway in murine 3T3-L1 adipocytes.

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) accumulates in human body, probably influencing adipocyte differentiation and causing various toxic effects, including wasting syndrome. Recently, orientin, a phenolic compound abundant in natural health products, has been shown to have antioxidant properties. We investigated the protective effects of orientin against TCDD-induced adipocyte dysfunction and its underlying mechanisms. In this study, orientin suppressed TCDD-induced loss of lipid accumulation. Orientin inhibited TCDD-driven decreases in the levels of peroxisome proliferator-activated receptor γ and adiponectin. Orientin also reduced TCDD-induced prostaglandin E2, and cytosolic phospholipase A2α levels, and increased TCDD-inhibited peroxisome proliferator-activated receptor gamma coactivator 1-alpha levels in 3T3-L1 adipocytes. TCDD reduced the levels of insulin receptor substrate 1 and glucose transporter 4, and decreased insulin-stimulated glucose uptake activity; however, orientin diminished these TCDD-induced effects. These results suggest that orientin may have beneficial effects on the prevention of TCDD-induced wasting syndrome and type II diabetes mellitus accompanied by insulin resistance.

Magnetic signatures of 120 K superconductivity at interfaces in La2CuO4+δ.

In self-assembled vertically aligned nanocomposite (VAN) thin films of La2CuO4+δ + LaCuO3, we find from DC magnetic susceptibility measurements, weak signatures of superconductivity at ∼120 K. This compares to a maximum TC of 40 K in bulk La2CuO4+δ. The 120 K signature occurs only when both c-axis and a-axis oriented La2CuO4+δ grains are present in the films. The superconductivity was lost after 3 months of storage but was recovered by annealing in oxygen. From lattice parameter analyses undertaken close to the c/a grain boundaries, it was determined that expansion of the La perovskite block in c-La2CuO4+δ enables the differently oriented grains to join at the interface. This expansion is consistent with the higher TC interfacial region. The work shows a new direction for increasing TC in cuprates - namely careful strain engineering of the crystal structure independently in-plane and out-of-plane.

Vertical Strain-Driven Antiferromagnetic to Ferromagnetic Phase Transition in EuTiO3 Nanocomposite Thin Films.

Three-dimensional (3D) strain induced in self-assembled vertically aligned nanocomposite (VAN) epitaxial films provides an unrivaled method to induce very large strains in thin films. Here, by growing VAN films of EuTiO3 (ETO)-Eu2O3 (EO) with different EO fractions, the vertical strain was systematically increased in ETO, up to 3.15%, and the Eu-Ti-Eu bond angle along ⟨111⟩ decreased by up to 1°, leading to a weakening of the antiferromagnetic interactions and switching from antiferromagnetic to ferromagnetic behavior. Our work has shown for the first time that Eu-Ti-Eu superexchange interactions play a key role in determining the magnetic ground state of ETO. More broadly, our work serves as an exemplar to show that multifunctionalities in strong spin-lattice coupling perovskite oxides can be uniquely tuned at the atomic scale using simple VAN structures.

Se-methylselenocysteine stimulates migration and antioxidant response in HaCaT keratinocytes: Implications for wound healing.

BACKGROUND: Se-methylselenocysteine (MSC), a natural organic selenium compound, is known for its anticancer effects. In the present study, we investigated the effects of MSC on cell migration, which is the most limiting step in the reepithelialization process of wound healing and the antioxidant response in HaCaT keratinocytes. METHODS: HaCaT cells were treated with various concentrations of MSC. Cell migration and proliferation, the expression of proteins that are involved in the epidermal-mesenchymal transition (EMT) process, the extent of oxidative stress and the antioxidant response, and the associated signaling pathways were analyzed. RESULTS: MSC (100-500 µM) increased HaCaT cell migration. MSC stimulated EMT, which was evidenced by a decrease in E-cadherin in the cells at the wound edge and increases in Snail, Twist, and matrix metalloproteinases. MSC increased the phosphorylation of Akt and glycogen synthase kinase 3ß, which led to the stabilization and nuclear accumulation of ß-catenin, a transcriptional coactivator involved in EMT. MSC caused a transient increase and then an eventual decrease in cellular reactive oxygen species, which appeared to be associated with the increase in nuclear factor erythroid 2-related factor 2, a key transcription factor for the antioxidant response. CONCLUSION: Our results suggest that MSC can promote skin wound healing by stimulating keratinocyte migration and, moreover, can protect cells from excessive oxidative stress that often accompanies and impairs the wound healing process, particularly in chronic wounds, by stimulating an antioxidant response.

Tetrabromobisphenol A Promotes the Osteoclastogenesis of RAW264.7 Cells Induced by Receptor Activator of NF-kappa B Ligand In Vitro.

BACKGROUND: Tetrabromobisphenol A (TBBPA), one of the most widely used brominated flame-retardants, is a representative persistent organic pollutants group. Studies on TBBPA toxicity have been conducted using various target cells; however, few studies have investigated TBBPA toxicity in bone cells. Therefore, this study investigated the in vitro effects of TBBPA on osteoclasts, a cell type involved in bone metabolism. METHODS: RAW264.7 cells were cultured in medium containing 50 ng/mL receptor activator of nuclear factor kappa B ligand (RANKL) and varying concentrations of TBBPA. To evaluate the effects of TBBPA on the differentiation and function of osteoclasts, osteoclast-specific gene expression, tartrate-resistant acid phosphatase (TRAP) activity, bone resorbing activity, mitochondrial membrane potential (MMP) and mitochondrial superoxide were measured. RESULTS: The presence of 20 µ TBBPA significantly increased TRAP activity in RANKL-stimulated RAW264.7 cells, the bone resorbing activity of osteoclasts, and the gene expression of Akt2, nuclear factor of activated T-cells cytoplasmic 1, and chloride channel voltage-sensitive 7. However, TBBPA treatment caused no change in the expression of carbonic anhydrase II, cathepsin K, osteopetrosis-associated transmembrane protein 1, Src, extracellular signal-related kinase, GAB2, c-Fos, or matrix metalloproteinase 9. Furthermore, 20 µ TBBPA caused a significant decrease in MMP and a significant increase in mitochondrial superoxide production. CONCLUSION: This study suggests that TBBPA promotes osteoclast differentiation and activity. The mechanism of TBBPA-stimulated osteoclastogenesis might include increased expression of several genes involved in osteoclast differentiation and reactive oxygen species production.

Inter-rater agreement among multiple examiners for the assessment of plaque scores between quantitative light-induced fluorescence-digital and two-tone disclosing solution-stained digital images.

BACKGROUND: To utilize plaque scoring indices as objective measures, a certain standard of intra-rater and inter-rater agreement must be met. Achievement of high consistency among several examiners in the assessment of images from Q-ray cam (for quantitative light-induced fluorescence-digital imaging) and digital single-lens reflex camera of stained tooth surfaces might enable more efficient undertaking of large epidemiological studies and oral tests. METHODS: Second-year dental hygiene students and registered dental hygienists 40 examiners were randomly selected, all of whom provided informed consent. Multiple examiners assessed plaque scoring indices from the two types of images of the same 30 patients. The images were observed on a computer monitor, and the area with dental plaque was assessed using the Patient Hygiene Performance Index. The intra-class correlation coefficient was determined to evaluate the agreement among examiners and test methods for dental plaque Q-ray cam and digital single-lens reflex camera measurements were compared using a Bland-Altman plot. The intra-class correlation coefficient was analyzed using SPSS version 24 software (SPSS Inc., Chicago, IL, USA), and the exploratory graph was analyzed with MedCalc. RESULTS: Agreement among 40 examiners was excellent with an intra-class correlation coefficient of 0.990 when the Q-ray cam was used. The intra-class correlation coefficient for the registered dental hygienists group was 0.987 and that for the dental hygiene students group was 0.980. CONCLUSIONS: The study was high agreement in the assessment of Q-ray cam images and digital single-lens reflex camera images of stained dental plaque by multiple examiners, confirming that the two methods are validated both independently and with high mutual agreement.