Perception Threshold Research Articles

Perceptual sensitivity to labeling stereotyped emotion expressions: Associations with age and subclinical psychopathology symptoms from childhood through early adulthood.

This study investigates (a) age-related differences in how the intensity of stereotyped facial expressions influence the emotion label children, adolescents, and adults assign to that face and (b) how this perceptual sensitivity relates to subclinical symptoms of psychopathology. In 2015-2016, 184 participants aged 4-25 years viewed posed stereotypes of angry, fearful, sad, and happy expressions morphed with neutral expressions at 10%-90% intensity. Thin plate regression smoothing splines were used to chart nonlinear associations between age and the perceptual threshold participants needed to assign the emotion label expected based on cultural consensus. Results suggest that sensitivity to labeling stereotypical happy faces as "happy" peaked by age 4. Sensitivity to perceiving stereotypical angry faces as "angry" increased from ages 4 to 7 and then plateaued. In contrast, sensitivity to perceiving stereotypical fearful and sad faces demonstrated protracted development, not reaching a plateau until ages 15 and 16, respectively. Reduction in selecting the "I don't know" response was the primary driver of these age-related changes. Stereotyped fear expressions required the highest intensity to be labeled as such and showed the most marked change in perceptual threshold across development. Interestingly, lower intensity morphs of stereotypical fear faces were frequently labeled "sad." Furthermore, perceiving lower intensity fear morphs was associated with fewer internalizing and externalizing symptoms in participants aged 7-19. This study describes the development of perceptual sensitivity to labeling stereotypical expressions of emotion according to cultural consensus and shows that how people perceive and categorize ambiguous facial expressions is associated with vulnerability to psychopathology. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Using biothesiometer, Neuropathy Symptom Score, and Neuropathy Disability Score for the early detection of peripheral neuropathy: A cross-sectional study.

Patients with peripheral neuropathy could have damaged peripheral nerves, which leads to sensory and motor dysfunction. Diabetes, infections, and trauma are the major causes of peripheral neuropathy. Vibratory perception threshold (VPT) tools are commonly used to detect peripheral neuropathy. This study aims to determine the assessment of peripheral neuropathy through the different diagnostic tools in the community in Malaysia. A total number of 1283 participants were recruited from the seven retail pharmacies located in Selangor, Malaysia. The peripheral neuropathy test was conducted based on VPT tools on both feet using the digital biothesiometer. Following that, Neurological Symptom Score (NSS) and Neurological Disability Score (NDS) were taken from the participants to assess the neurological symptoms. Participants had an average age of 40.6 ± 12.9 years and were mostly of Chinese ethnicity (54.1%). The findings show that increasing age was associated with more severe peripheral neuropathy across the various assessment tools, but gender differences were found with the biothesiometer test and ethnicity has severity in the biothesiometer and disability scores. The sensitivity and specificity of the biothesiometer test were 0.63 and 0.84, respectively. The combined tool NSS and NDS had high specificity and a high positive predictive value, suggesting that it could be a reliable indicator of peripheral neuropathy when both scores are elevated. The findings show that the biothesiometer test, NSS, and NDS are considered screening VPT tools for diagnosing peripheral neuropathy. However, further evaluation and diagnostic testing are necessary in cases of a positive test result.

Microsaccadic suppression of peripheral perceptual detection performance as a function of foveated visual image appearance.

Microsaccades are known to be associated with a deficit in perceptual detection performance for brief probe flashes presented in their temporal vicinity. However, it is still not clear how such a deficit might depend on the visual environment across which microsaccades are generated. Here, and motivated by studies demonstrating an interaction between visual background image appearance and perceptual suppression strength associated with large saccades, we probed peripheral perceptual detection performance of human subjects while they generated microsaccades over three different visual backgrounds. Subjects fixated near the center of a low spatial frequency grating, a high spatial frequency grating, or a small white fixation spot over an otherwise gray background. When a computer process detected a microsaccade, it presented a brief peripheral probe flash at one of four locations (over a uniform gray background) and at different times. After collecting full psychometric curves, we found that both perceptual detection thresholds and slopes of psychometric curves were impaired for peripheral flashes in the immediate temporal vicinity of microsaccades, and they recovered with later flash times. Importantly, the threshold elevations, but not the psychometric slope reductions, were stronger for the white fixation spot than for either of the two gratings. Thus, like with larger saccades, microsaccadic suppression strength can show a certain degree of image dependence. However, unlike with larger saccades, stronger microsaccadic suppression did not occur with low spatial frequency textures. This observation might reflect the different spatiotemporal retinal transients associated with the small microsaccades in our study versus larger saccades.

Influence of preheating and water storage on the color, whiteness, and translucency of modern resin-based composites.

To evaluate the influence of preheating and water storage on color, whiteness, and translucency of one-shaded, group-shaded, and multi-shaded resin-based composites. A total of 270 samples were fabricated from one-shaded (Omnichroma), group-shaded (Optishade MD), and multi-shaded (Enamel Plus HRI) resin-based composites and divided into six groups: no heating (control) and 1-5 heatings (test) (n = 15). The CIE L*, a*, b*, C*, and h° color coordinates were registered over white, black, and gray backgrounds with a spectrophotometer before and after 24, 72, 144 h water storage. Kruskal-Wallis test was used to evaluate differences in the color coordinates, whiteness index, and translucency parameter (α = 0.05). The Mann-Whitney U test was performed with a Bonferroni correction (p < 0.001) for pairwise comparisons. CIEDE2000 color, whiteness, and translucency differences between groups and subgroups were evaluated using their respective 50%:50% perceptibility and acceptability thresholds. Preheating influenced color coordinates, whiteness index, and relative translucency parameters (p < 0.001). Although color differences were below the acceptability threshold for all materials, translucency differences were above the acceptability threshold for Omnichroma. Water storage significantly influenced the whiteness index of Optishade MD (p < 0.001). Preheating had a more considerable effect on the color, whiteness, and translucency of one-shaded resin-based composite, while water storage influenced group-shaded resin-based composite more importantly. Preheating influences the color, whiteness level, and translucency of the resin-based composites, but the variations remain generally clinically acceptable; however, practitioners should be aware that the modifications in translucency for one-shaded resin-based composites could be more important than for group-shaded and multi-shaded resin-based composites.

Effect of Listerine and Chlorhexidine mouthwashes with antidiscoloration system on the colour change of CAD/CAM conventional and novel lithium disilicate ceramics

Background It has been reported that using mouthwashes can discolour the surface of teeth. Their effect on the stainability of newly introduced lithium disilicate ceramics is, however, unknown. Objective: The purpose of this in vitro study was to investigate how mouth washes affected the color change of new and conventional lithium disilicate (LS2) ceramics that were finished using various techniques. Materials and Methods A total of 56 ceramic slices were produced from conventional LS2 (E Max CAD, Ivoclar) and a novel virgilite based LS2 (Cerec Tessera, Dentsply Sirona). According to the finishing method, the specimens were divided into glazed and polished subgroups. Each subgroup was further subdivided into two based on immersion in chlorhexidine (CHXD) or Listerine (LIST) mouth washes. A handheld spectrophotometer was used to measure the color attributes, and color differences (ΔE00) were then counted using specific equation. Data were analyzed using ANOVA and Tukey’s post-hoc tests. Results Significant differences in color change (ΔE00) values were observed between conventional and novel LS2 ceramics, as well as between different finishing methods and mouth-rinse solutions. Chlorhexidine induced higher color differences than Listerine, with average ΔE00 values of 0.959 and 0.885, respectively (p &lt; 0.001). The polished specimens generally exhibited higher ΔE00 values than the glazed specimens, with average values of 1.071 and 0.792 for conventional LS2, and 0.836 and 0.786 for novel LS2 (p &lt; 0.001). However, most color changes did not exceed the perceptibility and acceptability thresholds. Conclusion Using CHXD and LIST mouth washes affected the color change of polished or glazed conventional and novel lithium disilicate ceramics. In general, the stainability of polished specimens was higher than that of glazed ones. There was more discoloration on specimens immersed in CHXD than those immersed in LIST. Bangladesh Journal of Medical Science Vol. 23 No. 04 October’24 Page : 1178-1184

ID: 327963 Clinical Paresthesia Perception Thresholds Decrease with Higher Spinal Cord Stimulation Frequency

ID: 327963 Clinical Paresthesia Perception Thresholds Decrease with Higher Spinal Cord Stimulation Frequency

The Role of a Biothesiometer in Early Detection and Management of Diabetic Neuropathy.

Diabetic foot ulcers (DFUs)have become a common and serious outcome of diabetes mellitus (DM). Diabetic peripheral neuropathy (DPN) is often underdiagnosed, which impairs the capacity to prevent foot ulceration. The clinical manifestations typically include sensory complaints, which leavepatients vulnerable to increased risk of injury without their awareness. The current study aims to assess the viability of VPT (vibration perception threshold) testing using a biothesiometer as an early diagnostic tool for detecting diabetic neuropathy and reducing the burden of diabetic foot disease. This prospective study was conducted in Dr. D. Y. Patil Medical College, Pimpri, Pune from August 2022 to July 2024 among 50 patients with DFUs. Ethical approval was taken from the Institutional Ethical Committee. An informed consent was obtained from all the study participants. VPT testing using a biothesiometer was done to assess the neurological status of the patient's limbs. A significant difference between the symptomatic and asymptomatic cases was also calculated to evaluate the co-relation of symptoms compared to VPT. The largest age group among those surveyed is 41-50 with a mean age of 50.72. Males form a slightly larger proportionthan females. A total of 22 (44%) ulcers are present over the plantar aspect of the foot. Out of the entire study, 37 (74%)individuals reported Grade II or III neuropathy, and 29 (58%)individuals reported no symptoms of diabetic neuropathy. The majority portion ofindividuals in the study had an HbA1c ranging from 6.5% to 8%. After an intervention, 44 (88%) patients did not experience a change in their VPT grading after six months. The chi-square test results suggest that the onset period of diabetes in years or the type of treatment history for diabetes does not significantly influence VPT grading among the surveyed individuals. However, individuals with higher HbA1c levels tend to exhibit more severe VPT impairments. Regular monitoring of VPT grading is crucial for early diagnosis of neuropathy, tracking disease progression, and assessing intervention effectiveness. Hence, we recommend all diabetic patientsregularly undergo biothesiometry as part of their routine diabetic check-ups to help prevent disease progressionand complications like amputations and improve their overall quality of life.

Predictive Value of Current Perception Threshold for Prognosis of Pulsed Radiofrequency in Patients with Acute Herpetic Neuralgia.

This study aimed to evaluate the prognostic accuracy of the Current Perception Threshold (CPT) in Acute Herpetic Neuralgia (AHN) patients receiving Pulsed Radiofrequency (PRF) therapy and to develop a corresponding prognostic model. We retrospectively analyzed data from 106 AHN patients treated with PRF between January 2022 and May 2023. The occurrence of Postherpetic Neuralgia (PHN) after treatment categorized patients into non-PHN and PHN groups. The predictive role of CPT indices for PRF outcomes was assessed using the Receiver Operating Characteristic (ROC) curve and Area Under Curve (AUC). Then the dataset was split into a training set (n=74) and a validation set (n=32). Factors associated with PHN development were identified using univariate and multivariate logistic regression. A nomogram model was developed using significant predictors and internal validation was performed using valid set data. Among the 106 patients, 45had a poor prognosis. Significant differences in age, preoperative Numerical Rating Scale (NRS) score, and 5Hz CPT ratio were observed between the groups (p<0.05). Logistic regression identified these factors as independent predictors for PRF prognosis (p<0.05). The 5Hz CPT ratio demonstrated predictive value (AUC= 0.764, 95% CI: 0.674-0.855). The nomogram model, incorporating these predictors, showed high AUC in both the training (0.863, 95% CI: 0.776-0.950) and validation sets (0.859, 95% CI: 0.721-0.998). Calibration curves indicated good model fit, and the Hosmer-Lemeshow test confirmed this (p>0.05). Decision Curve Analysis (DCA) highlighted the model's predictive advantage. The 5Hz CPT ratio can predict the prognosis of PRF in AHN patients. The nomogram model has high precision and clinical utility. It can help identify AHN patients with a poor PRF prognosis at an early stage and assist in clinical decision-making.

Reinforcement of 3D-printed resins for denture base by adding aramid fibers: Effect on mechanical, surface, and optical properties.

The present study evaluated the mechanical, surface, and optical properties of 3D-printed resins for removable prostheses reinforced by the addition of aramid fibers. According to ISO 20795-1:2013 standards, specimens were printed using a digital light processing 3D printer and divided into two groups (n=06/group): 3D-printed resin for denture base as the control group, and a group with the same 3D-printed resin in addition of 5% aramid fibers as the experimental group. Red aramid fibers were chosen for aesthetic characterization. The specimens were evaluated for their mechanical properties, such as elastic modulus (GPa), flexural strength (MPa), and superficial properties by their surface microhardness (KHN), surface roughness (μm), and surface free energy (mJ/m2). Optical properties were evaluated by the color difference (∆E00) between groups. The statistical test chosen after the exploratory analysis of the data was One-way ANOVA followed by Tukey's HSD (α=0.05). The results showed statistical differences in elastic modulus (p<0.0001), flexural strength (p<0.0001), surface free energy polar variable (p=0.0322), total surface free energy (p=0.0344), with higher values for the experimental. Surface hardness and surface roughness showed no statistical difference (p≥0.05). The color difference (∆E00) obtained through the CIEDE2000 calculus was below the perceptibility threshold (≤1.1). Adding aramid fibers to 3D-printed resin for denture bases resulted in better mechanical properties, without major alterations in surface properties. In addition, it is an easy-to-apply choice for mechanical reinforcement and aesthetic characterization, with the expression of small blood vessels in the 3D-printed resin for removable denture bases.

N-Check: nerve check to document chemotherapy-induced peripheral neuropathy (CIPN) in incurable cancer

Chemotherapy-induced polyneuropathy (CIPN) encompasses aspectrum of symptoms ranging from hypoesthesia with impaired gait, stance and fine motor skills to painful dysesthesia and allodynia and significantly impairs the quality of life of those affected. In the present pilot study, quantitative sensory testing (QST) was used to investigate CIPN as acommon adverse effect of cytostatic drugs in patients with incurable cancer. The QST is astandardized examination procedure that is not yet routinely used in cancer patients. It is used to examine thermal and mechanical perception and pain thresholds to record the subjectively experienced pain phenotype. In the N‑Check pilot project, the QST was used before and after tumor-specific, potentially CIPN-inducing treatment and the data collected was compared in apre-post analysis. In addition, the specific effects of CIPN on the health-related quality of life of patients treated primarily with apalliative intention were recorded using the Functional Assessment for Cancer Therapy-General (FACT-G) questionnaire. Overall, the patients showed significant heat hypoalgesia after chemotherapy as asign of damage to small nerve fibers. In addition, there were signs of deterioration of the quality of life. The feasibility of QST in patients with incurable cancer and palliative, neurotoxic chemotherapy was demonstrated in this pilot study.

Assessing the nonlinear impact of green space exposure on psychological stress perception using machine learning and street view images.

Urban green space (GS) exposure is recognized as a nature-based strategy for addressing urban challenges. However, the stress relieving effects and mechanisms of GS exposure are yet to be fully explored. The development of machine learning and street view images offers a method for large-scale measurement and precise empirical analysis. This study focuses on the central area of Shanghai, examining the complex effects of GS exposure on psychological stress perception. By constructing a multidimensional psychological stress perception scale and integrating machine learning algorithms with extensive street view images data, we successfully developed a framework for measuring urban stress perception. Using the scores from the psychological stress perception scale provided by volunteers as labeled data, we predicted the psychological stress perception in Shanghai's central urban area through the Support Vector Machine (SVM) algorithm. Additionally, this study employed the interpretable machine learning model eXtreme Gradient Boosting (XGBoost) algorithm to reveal the nonlinear relationship between GS exposure and residents' psychological stress. Results indicate that the GS exposure in central Shanghai is generally low, with significant spatial heterogeneity. GS exposure has a positive impact on reducing residents' psychological stress. However, this effect has a threshold; when GS exposure exceeds 0.35, its impact on stress perception gradually diminishes. We recommend combining the threshold of stress perception with GS exposure to identify urban spaces, thereby guiding precise strategies for enhancing GS. This research not only demonstrates the complex mitigating effect of GS exposure on psychological stress perception but also emphasizes the importance of considering the "dose-effect" of it in urban planning and construction. Based on open-source data, the framework and methods developed in this study have the potential to be applied in different urban environments, thus providing more comprehensive support for future urban planning.

Assessment of Surface Roughness, Color, and Bonding Efficacy: Self-Adhesive vs. Conventional Flowable Resin.

This in vitro study aimed to analyze the surface roughness (Ra) and color stability (ΔEab, ΔE00) following simulated mechanical brushing and to evaluate the microtensile (μTBS) of self-adhering resin flowable (SARF) to dentin. The selected materials were Constic, Yflow AS, and Tetric N flow (TNF/control). Thirty composite resin cylinders were fabricated for surface property evaluation. Ra and color were assessed both before and after simulated brushing. The thresholds of 50:50% perceptibility and acceptability of color differences in the evaluated resins were assessed. For μTBS analysis, fifteen molars were selected, sectioned to expose flat dentin surfaces, and restored according to the manufacturers' instructions for microtensile testing. There were statistically significant differences in Ra among the groups, with Constic exhibiting the highest Ra value (0.702 µm; p < 0.05), whereas Yflow AS presented the lowest Ra value (0.184 µm). No statistically significant difference in color was observed among the groups (p > 0.05). The 50:50% perceptibility and acceptability thresholds were set at 1.2 and 2.7 for ΔEab and 0.8 and 1.8 for ΔE 00. All the results fell within the acceptable limits. The mean μTBS values of Constic, Yflow AS, and TNF were 10.649 MPa, 8.170 MPa, and 33.669 MPa, respectively. This study revealed increased Ra and comparable color stability among all the tested composite resins after abrasion. However, the SARF exhibited lower μTBS compared to conventional using an adhesive system.

Efficacy and Safety of the Combination of Palmitoylethanolamide, Superoxide Dismutase, Alpha Lipoic Acid, Vitamins B12, B1, B6, E, Mg, Zn and Nicotinamide for 6 Months in People with Diabetic Neuropathy.

To investigate the efficacy of Palmitoylethanolamide (PEA, 300 mg), Superoxide Dismutase (SOD, 70 UI), Alpha Lipoic Acid (ALA, 300 mg), vitamins B6 (1.5 mg), B1 (1.1 mg), B12 (2.5 mcg), E (7.5 mg), nicotinamide (9 mg), and minerals (Mg 30 mg, Zn 2.5 mg) in one tablet in people with Diabetic Neuropathy (DN). In the present pilot study, 73 people (age 63.0 ± 9.9 years, 37 women) with type 2 Diabetes Mellitus (DMT2) (duration 17.5 ± 7.3 years) and DN were randomly assigned to receive either the combination of ten elements (2 tablets/24 h) in the active group (n = 36) or the placebo (n = 37) for 6 months. We used the Michigan Neuropathy Screening Instrument Questionnaire and Examination (MNSIQ and MNSIE), measured vibration perception threshold (VPT) with biothesiometer, and Cardiovascular Autonomic Reflex Tests (CARTs). Nerve function was assessed by DPN Check [sural nerve conduction velocity (SNCV) and amplitude (SNAP)]. Sudomotor function was assessed with SUDOSCAN, which measures electrochemical skin conductance in hands and feet (ESCH and ESCF). Pain score (PS) was assessed with Pain DETECT questionnaire. Quality of life was assessed by questionnaire. In the active group, there was a large improvement of pain (PS from 20.9 to 13.9, p < 0.001). There was also a significant improvement of vitamin B12 (B12) levels, MNSIQ, SNCV, VPT, and ESCF (222.1 vs. 576.3 pg/ mL, p < 0.001; 6.1 vs. 5.9, p = 0.017; 28.8 vs. 30.4, p = 0.001; 32.1 vs. 26.7, p = 0.001; and 72.2 vs. 74.8, p < 0.001 respectively). In the placebo group, neither pain (21.6 vs. 21.7, p = 0.870) or any other aforementioned parameters changed significantly, and MNSIE worsened (2.9 vs. 3.4, p < 0.001). As a result, changes from baseline to follow-up in pain, B12 levels, VPT, and MNSIQ differed significantly between the two groups (p < 0.001, 0.025, 0.009, and <0.001, respectively). CARTs, SNAP, ESCH did not significantly change in either of the two groups. The combination of the ten elements in one tablet for 6 months at a daily dose of two tablets in people with DN significantly improves pain, vibration perception threshold, and B12 levels.

Dental Color-Matching Ability: Comparison between Visual Determination and Technology.

The choice of the correct color is of paramount importance in esthetic dentistry; however, there is still no consensus on the best technique to determine it. The aim of the present study is to compare the accuracy of a recently introduced colorimeter in shade matching with human vision. In addition, possible variables affecting color-matching by human eye have been analysed. 18 disc-shaped composite samples with identical size and shape were produced from a composite flow system (Enamel plus HriHF, Micerium): Nine were considered control samples (UD 0-UD 6), and nine were test samples with identical flow composite shade to the control ones. Parallelly, 70 individuals (dental students and dental field professionals) were individually instructed to sit in a dark room illuminated with D55 light and to perform visual shade matching between control and test discs. An error matrix containing ΔE94 between control and test discs was generated, containing four match-clusters depending on perceptibility and acceptability thresholds. The frequency and severity of errors were examined. The colorimeter achieved a 100% perfect matching, while individuals only achieved a 78%. A higher occurrence of mismatches was noted for intermediate composite shades without a statistically significant difference. No statistically significant differences were reported for age, sex, and experience. A statistically significant difference was present among the Optishade match and the visual determination. The instrumental shade-matching evaluation proved to be significantly more reliable than the human visual system. Further research is needed to determine whether the same outcomes are achieved in a clinical setting directly on patients.

Exploring the optical behavior and relative translucency parameter of CAD-CAM resin-based composites, polymer-infiltrated ceramic network, and feldspar porcelain

ObjectivesTo evaluate and compare the optical properties and relative translucency parameter of CAD-CAM restorative materials. MethodsFour CAD-CAM materials were evaluated: Lava Ultimate (LU), Grandio Blocs (GB), VITA Enamic (VE), and VITA Mark II (VM). Disk-shaped samples in shade A2-HT were prepared (n = 10) and polished to 1.00 ± 0.01 mm of thickness. Scattering (S), absorption (K), albedo (a) coefficient, transmittance (T%), light reflectivity (RI), infinite optical thickness (X∞), and radiative transfer coefficients (μa, and μ′S) were calculated using Kubelka-Munk method and Thennadil's semi-empirical approach. Root Mean Square Error (RMSE) and Goodness of Fit (GFC) were used as performance optical behavior. Translucency differences were evaluated using the relative translucency parameter (RTP00) and 50:50 % translucency perceptibility and acceptability thresholds (TPT00 and TAT00). ResultsThe spectral distribution of S, K, T%, RI, and X∞ was wavelength-dependent. GFC and RMSE values indicated good spectral behavior matches and good comparative spectral values for RI in LU-GB, LU-VE, and GB-VE, and for K in VE-VM. VM displayed the highest scattering values across the wavelengths, while VE and VM showed lower absorption at shorter wavelengths. LU and GB had the highest transmittance. The X∞ values indicated that all 1.0 mm thick materials could be influenced by the background. No good spectral match and no good comparative spectral values were found between CAD-CAM materials and anterior bovine maxillary specimens. VM had the lowest RTP00 values with perceptible and unacceptable differences compared to CAD-CAM materials evaluated. SignificanceUnderstanding the optical behavior of different CAD-CAM materials was essential for guiding clinicians in material selection and optimizing their clinical performance. The findings confirm that the different compositions and microstructure impact the optical properties and translucency of CAD-CAM restorative materials.

48799 Defining Perceptual Thresholds for Hair Density Changes: A Study of Dermatologist Perceptions

48799 Defining Perceptual Thresholds for Hair Density Changes: A Study of Dermatologist Perceptions

A Study to Evaluate the Effect of Alpha-Lipoic Acid on Neuropathic Symptoms in Diabetic Neuropathy Patients on Gabapentin or Pregabalin.

Introduction Chronic hyperglycemia is a key factor in the development of diabetic peripheral neuropathy (DPN), contributing significantly to the progression of this condition through the induction of oxidative stress. Elevated blood glucose levels lead to increased production of reactive oxygen species (ROS), which cause damage to neuronal cells and exacerbate neuropathic symptoms. Alpha-lipoic acid (ALA) is a potent antioxidant that neutralizes ROS and reduces oxidative damage. By addressing the mechanisms of neuropathy, ALA mitigates the effects of chronic hyperglycemia through antioxidant regeneration, inflammation reduction, and endothelial function improvement. As a result, ALA is emerging as a promising intervention for managing oxidative stress and inflammation in DPN. Methods Prospective, double-blind, placebo-controlled study, a total of 52 DPN subjects on gabapentin or pregabalin were randomly assigned to either ALA 600 mg oral once daily or placebo oral once daily for 12 weeks. Treatment outcome was assessed using vibration perception threshold (VPT), Neuropathy Total Symptom Score 6 (NTSS-6), quality of life (QOL) assessed by 12-Item Short Form Health Survey (SF-12) Questionnaire, oxidative stress biomarkers (malondialdehyde (MDA), nitric oxide (NO), and glutathione (GSH)) and inflammatory biomarker (high-sensitivity C-reactive protein (hs-CRP)) at baseline and every visit (four, eight, and 12 weeks). Neuron-specific enolase (NSE) levels were done at baseline and 12 weeks. Glycated hemoglobin (HbA1C) and safety parameters were done at screening and 12 weeks. Compliance with the study medication was assessed by pill count. Reported adverse drug reactions were recorded. Results A total of 52 subjects (males = 22; females = 30) with a mean age of 55.63 ± 7.5 years were randomized to receive either ALA or placebo. A significant reduction in VPT was observed with ALA at 12 weeks compared to baseline (from 26.92 ± 3.58 to 22.14 ± 1.94; p < 0.0001). Secondary parameters like NTSS-6, QOL by SF-12 questionnaire, NSE levels, oxidative biomarkers levels, and inflammatory biomarkers showed significant improvement with ALA compared to placebo. No serious adverse events were reported. Conclusion ALA demonstrated a protective effect against DPN by its antioxidant and anti-inflammatory effects and was found to have good safety.

Effectiveness of Three Bleaching Techniques for Endodontically Treated Teeth: A Randomized Clinical Trial.

Various techniques, products, and protocols are used for the bleaching of non-vital teeth. The walking bleach technique involves sealing the bleaching agent in the pulp chamber. In the inside/outside technique, a low-concentration bleaching agent is applied at home using a custom tray. In the in-office technique, a high-concentration bleaching agent is applied by a dental professional. Limited research has compared the effectiveness of these techniques. This clinical trial aimed to evaluate the effectiveness of the walking bleach, the inside/outside, and the in-office bleaching techniques. Fifty-four discolored teeth were selected according to eligibility criteria, randomized, and assigned to three treatment groups (n=18): walking bleach (sodium perborate - SP), inside/outside bleaching (7.5% hydrogen peroxide -HP7.5), and in-office bleaching (35% hydrogen peroxide - HP35). A cervical seal was placed in all the teeth, and nonvital bleaching was performed according to each technique. The CIELab color coordinates were measured using a clinical spectrophotometer at baseline, weekly, and at the 1-week follow-up. ΔE00 and ΔWID were calculated between the baseline and each evaluation time point. The ANOVA, Fisher exact, and Kruskal-Wallis tests were used to compare the quantitative variables, and the Fisher exact test, to determine the association among categorical variables. Bleaching effectiveness was interpreted by 50:50% perceptibility and acceptability thresholds. As the treatment progressed, all techniques presented a significant increase in L* and WID (p<0.001), and a significant decrease in a* and b* (p<0.001). HP7.5 and HP35 presented greater increases in WID mean values, in comparison with SP (p=0.006). No significant differences were observed among the techniques for ΔE00 after treatment completion (p=0.383). There were no statistical differences in bleaching effectiveness among the techniques after treatment completion (p=0.098). All techniques presented excellent effectiveness after treatment completion. However, HP7.5 and HP35 techniques provided a more rapid whitening response.

Exploring the CIEDE2000 thresholds for lightness, chroma, and hue differences in dentistry

ObjectiveTo evaluate the perceptibility and acceptability CIEDE2000 (KL:KC:KH) thresholds for lightness, chroma and hue differences in dentistry. MethodA Python-based program was developed to conduct a psychophysical experiment based on visual assessments of computer-simulated images of human teeth. The experiment was performed on a calibrated display. A 40-observer panel: dentists and laypersons (male and female; n=10), evalu- ated three subsets of simulated human teeth: the lightness subset (%∆L00 ≥ 98 %), the chroma subset (%∆C00 ≥ 98 %) and the hue subset (%∆H00 ≥ 98 %), using ∆E00 ≥ 5 units. A Takagi-Sugeno-Kang Fuzzy Approximation model was used as fitting procedure, and 50:50 % lightness, chroma and hue CIEDE2000 (1:1:1) and CIEDE2000 (2:1:1) perceptibility (PT00) and accept- ability (AT00) thresholds were calculated. Data was statistically analyzed using t-test (p < 0.05). ResultsThe 50:50 % PT00 for KL=1 were ∆L00=1.04, ∆C00=1.58 and ∆E00=1.01; and for KL=2 were ∆L00=0.51, ∆C00=1.58 and ∆E00=0.71. The 50:50 % AT00 for KL=1 were ∆L00=2.82, ∆C00=3.04 and ∆E00=2.66; and for KL=2 were ∆L00=1.40, ∆C00=3.04 and ∆E00=1.78. PT00 and AT00 ∆H00 may be considered no computable. A significant difference was found between CIEDE2000(1:1:1) and CIEDE2000(2:1:1), between lightness and chroma metrics, and between observer groups. No differences for lightness and chroma PT00 were found between male and female groups. ConclusionsIt is important to use PT00 and AT00 for lightness, chroma and hue specific to evaluate perceptual sensitivity for color changes in the tooth color space. AT00 for lightness and chroma are influenced by the observer's experience and gender. Males and laypersons show more tolerance for changes in chroma (∆C00) and in lightness (∆L00). SignificanceHue and chroma mismatch are more difficult to be accepted in dental color space.

Predictors of pharyngeal electrical stimulation treatment success in tracheotomised stroke patients with dysphagia: Secondary analysis from PHADER cohort study

Pharyngeal electrical stimulation (PES) has emerged as a promising intervention for neurogenic dysphagia, with potential benefits in reducing dysphagia severity in stroke patients. PES may facilitate decannulation in tracheotomised stroke patients with dysphagia, yet the predictive factors for treatment success have not been investigated in detail. This study used data from the PHAryngeal electrical stimulation for treatment of neurogenic Dysphagia European Registry (PHADER) study to identify predictive factors for PES treatment success among patients with post stroke dysphagia who required mechanical ventilation and tracheotomy. Multiple linear regression was performed to predict treatment success, as measured in improvement in dysphagia severity rating scale (DSRS), accounting for age, sex, stroke type, lesion location, baseline National Institutes of Health Stroke Scale (NIHSS) score, feeding status, time from stroke onset to PES, PES perceptual threshold and PES stimulation intensity at the first session. Cox regression was conducted to identify the predictors for decannulation for all participants. Ninety-eight participants (mean [SD] age ​= ​66.6 [13.0]; male 73.5%) were included in the analyses. Regression analyses showed that early intervention (p ​= ​0.004) and younger age (p ​= ​0.049) were significant predictors for treatment success. For participants who received PES during tracheotomy (n ​= ​60; mean [SD] age ​= ​66.6 [11.2]; male 73.3%), supratentorial stroke (p ​= ​0.033) and feeding status at baseline (p ​= ​0.025) were predictors of treatment success. Among all participants, early intervention was associated with higher likelihood of decannulation (p ​= ​0.026). These results highlight the importance of timely intervention, age and stroke location in PES treatment success for stroke patients with mechanical ventilation and tracheotomy.