Comparative Evaluation of Antimicrobial Efficacy of Fluoride-Based and Self-Assembling Peptide P11-4-based Tooth Remineralization Agents on Streptococcus mutans: A Microbiological Study.

Background: Dental caries is a biofilm-related oral disease that continues to afflict the majority of the world's population. The disease results from an interaction between specific bacteria and dietary constituents within a biofilm known as dental plaque. Among the cariogenic microorganisms, Streptococcus mutans (S. mutans) plays pivotal role in caries-inducing processes. Objectives: Evaluate and compare the antimicrobial efficacy of self-assembling peptide P11-4-based tooth remineralization agents on S. mutans. Materials and Methods: An in vitro microbiological study. The antibacterial efficacy of self-assembling peptide P11-4 gel (Group 1), fluoride enhanced hydroxyapatite gel (Group 2), acidulated phosphate fluoride gel (Group 3), chlorhexidine gluconate gel 1.0% w/w (Group 4; positive control), and normal saline (Group 5; negative control) was performed using time-kill assay over a period of 24 h and the number of S. mutans colony-forming units (CFUs) were calculated. Statistical Analysis: Statistical analysis was done using Kruskal-Wallis test and Mann-Whitney post hoc Test. The level of significance was set at P < 0.05. Results: Group 1 showed mean CFUs (× 103) of 841.33 ± 3.51, Group 2 showed 10035.33 ± 60.68, Group 3 showed 1058.00 ± 56.96, Group 4 showed 0.00 ± 0.00, and Group 5 showed mean CFUs with 15226.67 ± 96.67. The difference in the mean CFUs (× 103) between different groups was statistically significant at P < 0.001. Conclusion: The self-assembling peptide P11-4-based tooth remineralization agent exhibited an inhibitory influence on S. mutans and hence formation of cariogenic bacteria dominant biofilm can thus be affected by its application.

Determining the best anti-microbial properties of dental cements used for pulp capping procedures using deep dentinal carious material.

Introduction: The exposure of the healthy pulp in cases of deep dentinal caries (DDC) that contain carious microorganisms can be prevented by placing a layer of pulp capping agent on the affected dentin. The cements used for pulp-capping should also ensure good anti-microbial properties. The present study was carried out to detect the antimicrobial efficacy of the commonly used cements by culturing the samples directly from DDC. Aims: To determine the efficacy of dental cements in the growth inhibition of microorganisms involved in DDC using direct contact anaerobic culture test. Method: 100 samples of DDC were collected in RTF. Ten microliters of the specimen containing RTF was incubated in thioglycolate broth consisting of 1 mm3 cement blocks of GIC, CaOH2, ZnOE and MTA anaerobically for 24 hours. This was further sub-cultured using selective media for streptococcus mutans, lactobacillus and bifidobacterium. Growth inhibition was measured by calculating the number of CFUs and statistically analysed using ANOVA and Tukey's post-hoc tests. Results: Tests showed variation in the anti-microbial effects of the cements and was highly significant at P < 0.001. Bifidobacterium showed most number of CFUs. MTA was the most effective pulp capping agent exhibiting 87.13% reduction in microbial growth, followed closely by ZnOE (84.6%). Conclusion: A conservative approach to treat DDC is the need of the hour which calls for the use of pulp capping cements of good antimicrobial efficacy. The current study revealed bifidobacterium to be the most prevalent in DDC and the cement that would best inhibit the mixed culture growth was MTA followed closely by ZnOE.

Influence of different irrigant activation methods on apical debris extrusion and bacterial elimination from infected root canals.

Introduction: The study aimed to determine the apical debris extrusion and microbial elimination from infected root canals after using different irrigant activation methods. Materials and Methods: Forty freshly extracted human mandibular premolars were selected and randomly assigned to four groups (n = 10). The teeth were mechanically prepared, sterilized, and inoculated with Enterococcus faecalis for 1 week. Irrigation was done with 3% sodium hypochlorite following conventional syringe irrigation-Group 1, manual dynamic agitation (MDA)-Group 2, passive ultrasonic irrigation (PUI)-UltraX -Group 3, and sonic irrigation (SI)-EndoActivator -Group 4, and the extruded debris were collected using Myers and Montgomery model. The microbial samples were taken from the canals using sterile paper points, cultured and recorded as colonies. The amount of extruded debris was measured by subtracting the final weight of the Eppendorf tube with debris from the initial weight of the tube. Results: I. Group 3 showed the least apical debris extrusion (P < 0.05), followed by Groups 2 and 1 and the highest with Group 4. II. Group 3 showed the least colony-forming units (CFUs)/ml, followed by Group 4, and finally, Group 2 showed lesser mean CFUs/ml compared to Group 1 (P < 0.05). Conclusion: All the irrigation activation methods were associated with apical debris extrusion, with the PUI system extruding the least amount of debris compared to the other groups. Irrigation activation techniques were beneficial in reducing the microbial load from the infected canals with the PUI system showing a complete elimination of the microbes, followed by SI and MDA.

Antimicrobial Efficacy of Commercially Available Low-fluoride and Fluoride-free Dentifrices for Children.

AIM AND OBJECTIVE: The objective of this study was to evaluate and compare the antimicrobial efficacy of low-fluoride and fluoride-free dentifrices against Streptococcus mutans. MATERIALS AND METHODS: The antimicrobial efficacy of four commercially available low-fluoride child formula dentifrices and four fluoride-free dentifrices against S. mutans was determined using the agar diffusion test. Fifty microliters of various dilutions (1:1, 1:2, 1:4) of each dentifrice were inoculated on the assigned plates under aseptic conditions. Saline was taken as negative control and 0.2% chlorhexidine was considered as a positive control. The plates were incubated at 37°C for 24 hours and the zone of inhibition around the wells was measured. RESULTS: All the tested low-fluoride dentifrices showed varying degrees of antimicrobial activity against S. mutans with F2 (Pediflor®) and F4 (Cheerio™) showing greater zones of inhibition when compared to F1 (Colgate®kids) and F3 (Kidodent). When the mean zones of inhibition produced by non-fluoridated dentifrices were compared with that of fluoridated dentifrices, no statistically significant difference was noted between NF1, NF3, NF4, and F2, F4. The antibacterial activity of F1 and F3 was significantly lower when compared to others. However, no antibacterial activity was noted with NF2. CONCLUSION: Both low-fluoride and fluoride-free formulations tested in the study exhibited antimicrobial activity against S. mutans. In very young children where the risk of fluorosis is of concern, fluoride-free formulations can be considered as safe alternatives to fluoride formulations. CLINICAL SIGNIFICANCE: Several dentifrices, both fluoride-free and low-fluoride formulations, are being aggressively marketed for young children. Though these toothpastes are being very commonly used by young parents for their infants and toddlers, there is very little published literature available on their antimicrobial activity and this study focuses on addressing this. HOW TO CITE THIS ARTICLE: Reddy D, Selvan A, Paul ST, et al. Antimicrobial Efficacy of Commercially Available Low-fluoride and Fluoride-free Dentifrices for Children. Int J Clin Pediatr Dent 2021;14(2):183-186.

Diplopia as the presenting feature of acute lymphoblastic leukemia.

PURPOSE: To report a rare case of acute lymphoblastic leukemia presenting with diplopia to an ophthalmologist. OBSERVATIONS: A 29-year-old male patient presented to ophthalmology department with sudden onset of binocular diplopia in left gaze. Magnetic resonance imaging of brain and orbits revealed a thickened left medial rectus, with enhancement of right sixth nerve, bilateral third and fifth nerves. Bone marrow biopsy revealed acute lymphoblastic leukemia (ALL) with a Burkitt-type chromosomal translocation-t(8; 14) and the patient was started on chemotherapy. CONCLUSION AND IMPORTANCE: This was a case of incomitant esotropia worse with left gaze due to left medial rectus infiltration mimicking a left sixth cranial nerve paresis. Diplopia can be the only presenting symptom of ALL and it can involve either an extraocular muscle or a cranial nerve.

Hierarchical Cluster Analysis to Aid Diagnostic Image Data Visualization of MS and Other Medical Imaging Modalities.

Perceiving abnormal regions in the images of different medical modalities plays a crucial role in diagnosis and subsequent treatment planning. In medical images to visually perceive abnormalities' extent and boundaries requires substantial experience. Consequently, manually drawn region of interest (ROI) to outline boundaries of abnormalities suffers from limitations of human perception leading to inter-observer variability. As an alternative to human drawn ROI, it is proposed the use of a computer-based segmentation algorithm to segment digital medical image data.Hierarchical Clustering-based Segmentation (HCS) process is a generic unsupervised segmentation process that can be used to segment dissimilar regions in digital images. HCS process generates a hierarchy of segmented images by partitioning an image into its constituent regions at hierarchical levels of allowable dissimilarity between its different regions. The hierarchy represents the continuous merging of similar, spatially adjacent, and/or disjoint regions as the allowable threshold value of dissimilarity between regions, for merging, is gradually increased.This chapter discusses in detail first the implementation of the HCS process, second the implementation details of how the HCS process is used for the presentation of multi-modal imaging data (MALDI and MRI) of a biological sample, third the implementation details of how the process is used as a perception aid for X-ray mammogram readers, and finally the implementation details of how it is used as an interpretation aid for the interpretation of Multi-parametric Magnetic Resonance Imaging (mpMRI) of the Prostate.

A Comparison of Antibacterial Efficacy of 0.5% Sodium Fluoride Impregnated Miswak and Plain Miswak Sticks on Streprococcus mutans - A Randomized Controlled Trial.

INTRODUCTION: Miswak (Salvadora persica) is a tooth cleaning stick made from the Salvodora Persica tree. It serves as a natural dentifrice with anti-bacterial, anti-plaque and anti-fungal properties. Fluoride, impregnated in chewing sticks will bestow comparable safety against dental caries as the fluoride containing dentifrice. AIM: The aim of the present study was to assess and compare the anti-bacterial effect of 0.5% sodium fluoride impregnated miswak and plain miswak sticks on Streptococcus mutans. MATERIALS AND METHODS: A randomized controlled concurrent parallel triple blind clinical trial was conducted for a period of 8 days. The trial included 30 subjects aged 20-23 years, who were randomly allocated in 1:1 ratio to Group A [0.5% Sodium Fluoride (NaF) impregnated Miswak sticks) and Group B (Plain Miswak sticks) respectively. The participants were instructed to chew miswak sticks for 6 minutes in the morning before breakfast. Unstimulated saliva was collected at baseline and after chewing miswak sticks to estimate S. mutans count using Mitis Salivarius Bacitracin agar. Data was statistically analyzed using paired and unpaired t-test. RESULTS: A statistically significant reduction in S. mutans Colony Forming Units (CFU) count in saliva was observed after using fluoridated miswak sticks compared to the baseline count (p=0.001). There was no significant difference in anti-bacterial effect of fluoridated miswak sticks and plain miswak sticks on S. mutans count (p=0.58). CONCLUSION: The efficacy of miswak impregnated with 0.5% NaF and plain miskaw sticks in reducing S. mutans counts in saliva is analogous.

Correlative (99m)tc-labeled tropane derivative single photon emission computer tomography and clinical assessment in the staging of Parkinson disease.

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by a selective loss of dopamine in the striatum. Problems remain in the accurate diagnosis of PD. The diagnosis of idiopathic PD is based on the interpretation of clinical signs and symptoms could be incorrect at the time of initial presentation. In vivo imaging of the dopaminergic system has the potential to improve the diagnosis of PD in its early stages. The imaging of dopamine transporter (DAT) with (99m)Tc-labeled tropane derivative (TRODAT-1) single photon emission computer tomography/computer tomography (SPECT/CT) has been proposed to be a valuable and feasible means of assessment of the integrity of dopamine neurons. The purpose of this study was to investigate the potential usefulness of (99m)Tc-TRODAT-1 imaging in the evaluation of patients with PD and classify into different stages of the disease. SPECT imaging with (99m)Tc-TRODAT-1 was conducted in 16 consecutive PD patients (9 men; 7 women) and in 6 age matched healthy volunteers (4 men; 2 women). The images were obtained 3 h after the intra-venous injection of the tracer. Specific uptake in the striatum and its sub-regions, including the putamen and caudate nucleus was calculated and the ratios of specific striatal binding to nonspecific occipital binding were calculated. ANOVA with Dunnett C post-hoc analysis was conducted using SPSS 20. A stepwise reduction in specific striatal uptake of (99m)Tc-TRODAT-1 with increasing disease severity between healthy control versus Stage I versus Stage II versus Stage III was found in PD patients (i.e., 3.77 vs. 2.56 vs. 1.57 vs. 0.63, P < 0.05). The changes were magnified by measurement of specific putaminal uptake (1.43 vs. 0.79 vs. 0.54 vs. 0.19, P < 0.05) and specific caudate uptake (1.90 vs. 1.47 vs. 0.73 vs. 0.27, P < 0.05). No remarkable adverse reactions were found in either healthy volunteers or PD patients during or after imaging. (99m)Tc-TRODAT-1 is accurate and widely available for the assessment of DAT activity, which might shed light on the integrity of the presynaptic nigrostriatal function. Our preliminary study results confirm the potential of using (99m)Tc-TRODAT-1 for DAT measurement, which is clinically important for the staging of PD.

Refractory coeliac disease associated with late onset epilepsy, ataxia, tremor and progressive myoclonus with giant cortical evoked potentials--a case report and review of literature.

Population-based screening studies suggest an overall prevalence of coeliac disease in Western populations of about 1%. A variety of neurological problems have been associated with coeliac disease occurring in up to 10% of cases of adult coeliac disease. We report an interesting case of a patient with coeliac disease who subsequently developed neurological symptoms several years later. Furthermore, a literature review of all cases to date was performed.

Multifocal motor neuropathy: the diagnostic spectrum and response to treatment.

OBJECTIVE: To define the clinical spectrum in a large cohort of patients with multifocal motor neuropathy (MMN) and the effectiveness of IVIg treatment. We also test two neurophysiologic criteria for conduction block (CB) for relevance to treatment responsiveness. METHODS: Retrospective case cohort analysis of 47 patients with MMN followed for up to 12 years. RESULTS: A total of 32 (70%) had an upper-limb onset with most showing clinical features of conduction block: weakened but non-wasted muscles (67%) and differential weakness across muscles supplied by a common terminal motor nerve (54%). Differential weakness of finger extension was a characteristic early sign. Application of consensus criteria for definite CB would have denied a trial of treatment to 6 patients with a typical phenotype compared with new criteria. No association was found between CB and presence of anti-GM1 ganglioside antibody. A total of 24 (51%) patients were treated with IVIg, which was associated with a marked initial improvement in self-reported disability in most patients. The magnitude of initial disability improvement was not sustained in all patients over time. However, the majority of treated patients reported significantly less disability at last follow-up than prior to treatment. Patients converted to a domiciliary IVIg program maintained function at least as well as hospital treated patients. CONCLUSION: The importance of the clinical phenotype of multifocal motor neuropathy (MMN) is emphasized. Neither conduction block (CB) nor antibody status is a reliable predictor of treatment responsiveness. Over-reliance upon consensus CB criteria can deny IVIg to patients with MMN who are treatment responsive.