Relationships between a clinical-visual scoring system and two histological techniques: a laboratory study on occlusal and approximal carious lesions

The anti-Alzheimer potential of Tamarindus indica: an in vivo investigation supported by in vitro and in silico approaches

Tamarindus indica Linn. (Tamarind, F. Fabaceae) is one of the most widely consumed fruits in the world. A crude extract and different fractions of T. indica (using n-hexane, dichloromethane, ethyl acetate, and n-butanol) were evaluated in vitro with respect to their DPPH scavenging and AchE inhibition activities. The results showed that the dichloromethane and ethyl acetate fractions showed the highest antioxidant activities, with 84.78 and 86.96% DPPH scavenging at 0.10 μg mL-1. The n-hexane, dichloromethane, and ethyl acetate fractions inhibited AchE activity in a dose-dependent manner, and the n-hexane fraction showed the highest inhibition at 20 μg mL-1. The results were confirmed by using n-hexane, dichloromethane, and ethyl acetate fractions in vivo to regress the neurodegenerative features of Alzheimer's dementia in an aluminum-intoxicated rat model. Phytochemical investigations of those three fractions afforded two new diphenyl ether derivative compounds 1-2, along with five known ones (3-7). The structures of the isolated compounds were confirmed via 1D and 2D NMR and HRESIMS analyses. The isolated compounds were subjected to extensive in silico-based investigations to putatively highlight the most probable compounds responsible for the anti-Alzheimer activity of T. indica. Inverse docking studies followed by molecular dynamics simulation (MDS) and binding free energy (ΔG) investigations suggested that both compounds 1 and 2 could be promising AchE inhibitors. The results presented in this study may provide potential dietary supplements for the management of Alzheimer's disease.

Visual or visual-tactile examination to detect and inform the diagnosis of enamel caries

BACKGROUND

The detection and diagnosis of caries at the initial (non-cavitated) and moderate (enamel) levels of severity is fundamental to achieving and maintaining good oral health and prevention of oral diseases. An increasing array of methods of early caries detection have been proposed that could potentially support traditional methods of detection and diagnosis. Earlier identification of disease could afford patients the opportunity of less invasive treatment with less destruction of tooth tissue, reduce the need for treatment with aerosol-generating procedures, and potentially result in a reduced cost of care to the patient and to healthcare services.

OBJECTIVES

To determine the diagnostic accuracy of different visual classification systems for the detection and diagnosis of non-cavitated coronal dental caries for different purposes (detection and diagnosis) and in different populations (children or adults).

SEARCH METHODS

Cochrane Oral Health's Information Specialist undertook a search of the following databases: MEDLINE Ovid (1946 to 30 April 2020); Embase Ovid (1980 to 30 April 2020); US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov, to 30 April 2020); and the World Health Organization International Clinical Trials Registry Platform (to 30 April 2020). We studied reference lists as well as published systematic review articles.

SELECTION CRITERIA

We included diagnostic accuracy study designs that compared a visual classification system (index test) with a reference standard (histology, excavation, radiographs). This included cross-sectional studies that evaluated the diagnostic accuracy of single index tests and studies that directly compared two or more index tests. Studies reporting at both the patient or tooth surface level were included. In vitro and in vivo studies were considered. Studies that explicitly recruited participants with caries into dentine or frank cavitation were excluded. We also excluded studies that artificially created carious lesions and those that used an index test during the excavation of dental caries to ascertain the optimum depth of excavation.

DATA COLLECTION AND ANALYSIS

We extracted data independently and in duplicate using a standardised data extraction and quality assessment form based on QUADAS-2 specific to the review context. Estimates of diagnostic accuracy were determined using the bivariate hierarchical method to produce summary points of sensitivity and specificity with 95% confidence intervals (CIs) and regions, and 95% prediction regions. The comparative accuracy of different classification systems was conducted based on indirect comparisons. Potential sources of heterogeneity were pre-specified and explored visually and more formally through meta-regression.

MAIN RESULTS

We included 71 datasets from 67 studies (48 completed in vitro) reporting a total of 19,590 tooth sites/surfaces. The most frequently reported classification systems were the International Caries Detection and Assessment System (ICDAS) (36 studies) and Ekstrand-Ricketts-Kidd (ERK) (15 studies). In reporting the results, no distinction was made between detection and diagnosis. Only two studies were at low risk of bias across all four domains, and 15 studies were at low concern for applicability across all three domains. The patient selection domain had the highest proportion of high risk of bias studies (49 studies). Four studies were assessed at high risk of bias for the index test domain, nine for the reference standard domain, and seven for the flow and timing domain. Due to the high number of studies on extracted teeth concerns regarding applicability were high for the patient selection and index test domains (49 and 46 studies respectively). Studies were synthesised using a hierarchical bivariate method for meta-analysis. There was substantial variability in the results of the individual studies: sensitivities ranged from 0.16 to 1.00 and specificities from 0 to 1.00. For all visual classification systems the estimated summary sensitivity and specificity point was 0.86 (95% CI 0.80 to 0.90) and 0.77 (95% CI 0.72 to 0.82) respectively, diagnostic odds ratio (DOR) 20.38 (95% CI 14.33 to 28.98). In a cohort of 1000 tooth surfaces with 28% prevalence of enamel caries, this would result in 40 being classified as disease free when enamel caries was truly present (false negatives), and 163 being classified as diseased in the absence of enamel caries (false positives). The addition of test type to the model did not result in any meaningful difference to the sensitivity or specificity estimates (Chi²(4) = 3.78, P = 0.44), nor did the addition of primary or permanent dentition (Chi²(2) = 0.90, P = 0.64). The variability of results could not be explained by tooth surface (occlusal or approximal), prevalence of dentinal caries in the sample, nor reference standard. Only one study intentionally included restored teeth in its sample and no studies reported the inclusion of sealants. We rated the certainty of the evidence as low, and downgraded two levels in total for risk of bias due to limitations in the design and conduct of the included studies, indirectness arising from the in vitro studies, and inconsistency of results.

AUTHORS' CONCLUSIONS

Whilst the confidence intervals for the summary points of the different visual classification systems indicated reasonable performance, they do not reflect the confidence that one can have in the accuracy of assessment using these systems due to the considerable unexplained heterogeneity evident across the studies. The prediction regions in which the sensitivity and specificity of a future study should lie are very broad, an important consideration when interpreting the results of this review. Should treatment be provided as a consequence of a false-positive result then this would be non-invasive, typically the application of fluoride varnish where it was not required, with low potential for an adverse event but healthcare resource and finance costs. Despite the robust methodology applied in this comprehensive review, the results should be interpreted with some caution due to shortcomings in the design and execution of many of the included studies. Studies to determine the diagnostic accuracy of methods to detect and diagnose caries in situ are particularly challenging. Wherever possible future studies should be carried out in a clinical setting, to provide a realistic assessment of performance within the oral cavity with the challenges of plaque, tooth staining, and restorations, and consider methods to minimise bias arising from the use of imperfect reference standards in clinical studies.

Shaping the future of dental education: Caries as a case-study

This study reports on the full-day workshop "The Shape of The Future of Dental Education for Dental Caries-and how we get there" held immediately prior to the May 2017 ADEE/ADEA/King's College London meeting "Shaping the Future of Dental Education." A standardised, evidence-led Core Curriculum in Cariology (CCC) was developed jointly and systematically by ORCA and ADEE, starting in 2010. At the same time, the ICDAS Foundation was developing a comprehensive caries management system, ICCMS™. The workshop reported on what has been achieved on a global basis by many building on these initiatives. The CCC has been, or is currently being, localised in a number of places around the world and has, in some countries, been successfully implemented. There are also other areas which are struggling more with the logistics of introducing it. The workshop presented geographical perspectives and experiences on implementing the CCC from Colombia, the United States and Europe, as well as professional perspectives from hygienists, students and policymakers. The workshop then considered the future of the CCC and the roles of Interprofessional Education, Technology, Global Networking and Assessment in a Global Context in 4 breakout groups. Having had reports back and plenary discussion, it was concluded that the caries world has made good progress towards a "futuristic" curriculum with parallel development of a comprehensive, preventive and tooth-preserving caries management system-ICCMS™. The implementation challenge is now to share even more effectively in order to have these developments more widely accepted and adopted worldwide.

Diagnostic performance of the visual caries classification system ICDAS II versus radiography and micro-computed tomography for proximal caries detection: an in vitro study

OBJECTIVES

The purpose of this study was: (a) to compare the visual caries classification system ICDAS II with conventional (CR) and digital radiography (DR) for diagnosis of non-cavitated caries on free proximal surfaces, (b) to examine the potential of micro-computed tomography (MCT) to substitute histological examination for the in vitro caries assessment.

METHODS

Both proximal surfaces of 20 teeth received classification separately by two examiners by means of the diagnostic modalities examined. The teeth were sectioned and assessed for depth of the lesion. The modalities were compared in terms of degree of inter-examiner agreement, sensitivity, specificity, accuracy, positive and negative predictive value and validity. Two diagnostic thresholds were applied: no caries versus all caries scores (D1), and no dentin caries versus dentin caries (D3).

RESULTS

The weighted kappa values for inter-examiner reproducibility for all diagnostic modalities were 0.51-0.81. Visual examination (ICDAS II) reached significant higher sensitivity (0.92-0.96) and negative predictive value (0.9-1) than radiography. Likewise, the radiographic modalities presented significantly higher specificity (0.93-1) and positive predictive values (0.92-1) than the ICDAS II criteria. The overall accuracy performance of radiographic modalities was related to the diagnostic threshold. MCT did not agree with histological validation at each disease severity scale.

CONCLUSIONS

The ICDAS II criteria are a promising tool for caries diagnosis on free proximal surfaces. DR and CR radiography present comparable performance. Furthermore, MCT is not capable of constituting a reliable alternative to histological examination for caries research.

In vitro ability of a laser fluorescence device in quantifying approximal caries lesions in primary molars

OBJECTIVES

This in vitro study aimed at evaluating the ability of Laser Fluorescence device (LFpen) in quantifying approximal caries lesions in primary molars.

METHODS

Two examiners assessed 123 approximal surfaces of primary molars using the DIAGNOdent pen (LFpen). Surfaces were determined to be either sound with white-spot lesions or have small cavitations. After sectioning, lesion depth was determined through polarized light microscopy. The intra-/inter-examiner agreement was calculated using intraclass correlation coefficient (ICC) and Bland-Altman analyses. Furthermore, Spearman correlation coefficients (Rs) were calculated between LFpen readings and lesion depth.

RESULTS

Correlation between LFpen values and lesion depth was low for both examiners (Rs=0.36 and 0.51), especially when cavitated lesions were excluded from the analysis (Rs=0.22 and 0.40). For all surfaces, ICC revealed intra- and inter-examiner reproducibility values of 0.75 and 0.63, respectively, but when only non-cavitated surfaces were analyzed, these values decreased (0.41 and 0.33, respectively).

CONCLUSIONS

LFpen readings present low correlation with approximal caries lesion depth and low reproducibility, especially in white-spot lesions. Therefore, the device could not be a suitable method for monitoring non-cavitated approximal caries lesion in primary molars.

The efficiency of operating microscope compared with unaided visual examination, conventional and digital intraoral radiography for proximal caries detection

Objective. The purpose of this study was to evaluate the efficiency of operating microscope compared with unaided visual examination, conventional and digital intraoral radiography for proximal caries detection. Materialsand Methods. The study was based on 48 extracted human posterior permanent teeth. The teeth were examined with unaided visual examination, operating microscope, conventional bitewing and digital intraoral radiographs. Then, true caries depth was determined by histological examination. The extent of the carious lesions was assessed by three examiners independently. One way variance of analysis (ANOVA) and Scheffe test were performed for comparison of observers, and the diagnostic accuracies of all systems were assessed from the area under the ROC curve (A_z). Results. Statistically significant difference was found between observers (P < .01). There was a statistically significant difference between operating microscope-film radiography, operating microscope-RVG, unaided visual examination-film radiography, and unaided visual examination-RVG according to pairwise comparison (P < .05). Conclusion. The efficiency of operating microscope was found statistically equal with unaided visual examination and lower than radiographic systems for proximal caries detection.

Occlusal caries: Evaluation of direct microscopy versus digital imaging used for two histological classification systems

OBJECTIVE

Histology is frequently used as a gold standard to validate caries detection devices. Poor assessment consistency could lead to apparent changes in diagnostic accuracy. In multi-center, multi-examiner studies electronic transfer of information would be convenient, provided there is no deteriation in quality. This study tested the hypothesis that examiner reproducibility in the assessment of caries lesion depth when viewing photographic images of histological sections on a computer monitor, is comparable with viewing the same sections under a microscope using two histological classification systems.

METHODS

166 investigation sites (96 teeth) were selected for visual examination (ICDAS-II) and sections made using a novel technique which reduced risk of section damage and allowed accurate allocation of section to each investigation site. Digital images of the sections were produced and four examiners viewed the sections under a microscope and on a separate occasion corresponding digital images on a computer monitor. Presence and extent of caries was scored according to two histological classification systems (Downer, ERK).

RESULTS

The inter- and intra-examiner reproducibility for both histological classification systems and both examination techniques was substantial to almost perfect (weighted kappa=0.63-0.90). Comparing the kappa values between microscopy and viewing digital images, there was no effect or only a small effect between both examination techniques (effect size 0.00-0.28). There was also a strong relationship between the two viewing techniques (r(s)=0.748-0.844).

CONCLUSIONS

Viewing digital images of tooth sections produces results comparable to viewing images directly under a microscope and therefore has potential benefits for multi-centre studies.

Radiographic diagnosis of incipient proximal caries: an ex-vivo study

The aim of this ex vivo study was to compare visual clinical and radiographic examinations to the histological analysis for proximal caries diagnosis in extracted permanent molars and premolars. The relationship between clinical aspects and carious lesions was also evaluated. Eighty-eight proximal surfaces (44 freshly extracted teeth) were longitudinally sectioned with a 370-µm diamond disk, thinned with wet silicon carbide paper and observed with a stereomicroscope at x40 magnification. Sensitivity and specificity were 65.6% and 83.3% for clinical examination and 29.7% and 95.8% for radiographic examination, respectively. Kappa values ranged from 0.64 to 0.91. The white spots corresponded to lesions restricted to enamel, while the dark spots corresponded to lesions that reached the dentinoenamel junction. In most cases, cavitation corresponded to dentin lesions. It may be concluded that interproximal radiographic examination is not a reliable method for detection of incipient proximal carious lesions.

Restorative treatment decision making with unaided visual examination, intraoral camera and operating microscope

This study assessed the restorative treatment options of the occlusal surfaces of teeth examined with unaided visual assistance, an intraoral camera and an operating microscope. Sixty-eight extracted human molars were mounted to perform mouth models with a premolar in contact on both sides. Four observers examined the models in a phantom head, which simulated clinical conditions, using three techniques: unaided visual examination, intraoral camera and operating microscope. The observers were asked to assess the occlusal surface of each tooth and make a treatment decision based on the following scale: 1) the occlusal surface being sound and "not needing a restoration," 2) the occlusal surface having a subsurface or enamel lesion. No operative treatment was needed at this visit, but special attention was given to this surface at recall visits: "preventive care-defer treatment" and 3) the surface had a carious lesion and "needed a restoration." The teeth were then sectioned in the mesio-distal direction and examined under a stereomicroscope with 10x magnification to determine the true extent of caries. Statistical analysis was conducted by calculating percentages and kappa values of the restorative treatment scores based on examinations by four observers. According to all the observers' treatment decisions, the kappa values were found to be 0.341 (p<0.001), 0.471 (p<0.001) and 0.345 (p<0.001) for unaided visual examination, intra-oral camera and operating microscope, respectively. There was a statistically significant difference between the intraoral camera and the other two methods (p<0.05), while there was no significant difference between the unaided visual examination and operating microscope (p>0.05). As a result of a comparison between the unaided visual examination and operating microscope, the use of an intraoral camera improved the restorative treatment decisions of the occlusal surfaces on posterior teeth.

Evaluation of Several Techniques for the Detection of Secondary Caries Adjacent to Amalgam Restorations

The objective of this study was to determine the ability of several techniques to detect natural secondary caries adjacent to proximal class II amalgam restorations. Two sites were selected and marked on each of 50 human extracted posterior teeth. Three examiners visually characterized each site independently for signs of demineralization (VI), ditching presence (VD), and color change, and utilized light-induced fluorescence (QLF), and infrared laser fluorescence (LF) techniques. The teeth were sectioned through the selected sites, and the severity of each lesion was determined by confocal laser scanning microscopy (CLSM) as the 'gold standard'. Agreement among examiners was assessed using weighted kappa statistics and showed fair to moderate correlation with all techniques. Sensitivity, specificity, positive predictive value (PPV), negative predictive value and accuracy were determined by utilizing three arbitrary CLSM thresholds. Higher sensitivity was indicated by the QLF and LF than by VI. For PPV and accuracy, QLF and LF showed values higher or similar to VI. Low sensitivity was found for VD. The results obtained in this study suggest that LF and QLF may improve the ability to detect early secondary caries around amalgam restorations.

Future directions in bonding resins to the dentine-pulp complex

Resin-based materials are rapidly becoming the primary restorative material to replace tooth structure and the low percentage of biological problems reported for resin-based restorations is testimony to their relative biocompatibility. Despite considerable advances in the understanding of the mechanisms, which govern the integration of resin composite materials with the dentine-pulp complex, considerable potential for improvement remains. Most of these improvements centre around a better understanding of the biological and microbiological risks of resin materials and will only be possible with improved in vitro and in vivo models. There are also a number of possible future developments in materials, clinical techniques and diagnostic methods that may improve the long-term success and reliability of resin-based restorations. The remainder of this paper describes the most likely avenues for future improvements.