Comparison among gold standard techniques used for the validation of methods for occlusal caries detection

ICCMS™ root caries lesions stages and their underlying depth towards the pulp: an in vitro study with histologic evaluation

OBJECTIVE

To examine the relationship between the ICCMS™ (International Caries Classification and Managing System) features of root caries lesions and the underlying depth of the lesion towards the pulp. In order to control for bias, the study followed the tailored document for risk of bias assessment (RoB-tool) recently published. A pilot study showed that the outline of the pulp was much clearer on horizontal compared to vertical sections through the lesions (p = 0.03) and that the histological stereomicroscopical (SM) assessed lesion depth towards the pulp was not influenced by the cutting direction (p = 0.155).

MATERIAL AND METHODS

A sample of extracted permanent molar teeth (n = 100) were classified independently by two of the authors according to ICCMS™ as no sign of root caries lesion 0 = sound; 1 = initial lesion (non-cavitated); 2 = moderate lesion (cavity depth ≤ 2 mm) and 3 = extensive lesion (cavity depth > 2 mm). After horizontal sectioning (HS) through the lesion, the depth of the underlying lesion was SM assessed independently by two of the authors as 0 = no lesion; 1 = lesion in outer 1/3; 2 = middle 1/3; and 3 = inner 1/3 of the dentine towards the pulp.

RESULTS

Intra- and inter-reproducibility (weighted kappa values ≥ 0.83); the accuracy (Spearman's rho-values) = 0.94 and 0.95; and specificity/sensitivities/AUC values (three different thresholds) were ≥ 0.91, ≥ 0.93, and ≥ 0.96, respectively.

CONCLUSION

Under the umbrella of the RoB-tool, the validity in terms of the reproducibility and accuracy of the ICCMS™ root caries scoring system was high.

CLINICAL RELEVANCE

By means of the ICCMS™ root caries scoring system, the underlying lesion depth can be estimated, which must be considered when managing the lesion.

STAndard Reporting of CAries Detection and Diagnostic Studies (STARCARDDS)

Aim

The aim of this paper is to present recommendations from an international workshop which evaluated the methodology and reporting of caries diagnostic studies. As a unique feature, this type of studies is focused on caries lesion detection and assessment, and many of them are carried out in vitro, because of the possibility of histological validation of the whole caries spectrum. This feature is not well covered in the existing reporting STARD guideline within the EQUATOR Network.

Participants and methods

An international working group of 13 cariology researchers was formed. The STARD checklist was reviewed and modified for caries detection and diagnosis purposes, in a three-step process of evaluation, consensual modification, and delivery during three 2-day workshops over 18 months. Special attention was paid to reporting requirements of caries studies that solely focus on reliability.

Results

The STARD checklist was modified in 14/30 items, with an emphasis on issues of sample selection (tooth selection in in vitro studies), blinding, and detailed reporting of results.

Conclusion

Following STARCARDDS (STAndard Reporting of CAries Detection and Diagnostic Studies) is expected to result in complete reporting of study design and methodology in future caries diagnosis and detection experiments both in vivo and in vitro, thus allowing for better comparability of studies and higher quality of systematic reviews.

Clinical relevance

Standardization of caries diagnostic studies leads to a better comparability among future studies, both in vivo and in vitro.

Identifying and Avoiding Risk of Bias in Caries Diagnostic Studies

Caries diagnostic studies differ with respect to their design, included patients/tooth samples, use of diagnostic and reference methods, calibration, blinding and data reporting. Such heterogeneity makes comparisons between studies difficult and could represent a substantial risk of bias (RoB) when it is not identified. Therefore, the present report aims to describe the development and background of a RoB assessment tool for caries diagnostic studies. The expert group developed and agreed to use a RoB assessment tool during three workshops. Here, existing instruments (e.g., QUADAS 2 and the Joanna Briggs Institute Reviewers' Manual) influenced the hierarchy and phrasing of the signalling questions that were adapted to the specific dental purpose. The tailored RoB assessment tool that was created consists of 16 signalling questions that are organized in four domains. This tool considers the selection/spectrum bias (1), the bias of the index (2) and reference tests (3), and the bias of the study flow and data analysis (4) and can be downloaded from the journal website. This paper explores possible sources of heterogeneity and bias in caries diagnostic studies and summarizes the relevant methodological aspects.

Histological validation of ICDAS II and radiological assessment of occlusal carious lesions in permanent teeth

The International Caries Detection and Assessment System (ICDAS) was introduced for a detailed evaluation of dental caries. The aim of the present study was to compare the ICDAS scores and radiologically evaluated caries depths to the histologically evaluated carious lesions in permanent teeth. 84 freshly extracted human teeth were included. Visual examination and scoring of the occlusal aspect were performed according to the ICDAS II criteria after completing a respective e-learning programme to support training in the use of ICDAS. Bucco-lingual digital X-ray images of the teeth were taken. Specimens were then fixed in formalin and embedded in a photocuring one-component methacrylate-based resin. Longitudinal sections were cut and stained with rhodamine B, fuchsin and acetic light green dye to assess the caries extension by light microscopic analysis. Assessing ICDAS II scores and histological findings, a rank correlation coefficient of r = 0.890 could be found. ICDAS II/radiology and histology/radiology showed correlation coefficients of r = 0.658 and 0.661, respectively. Evaluating receiver operating characteristic (ROC) curves, no exact predictability could be found for caries lesions in enamel for both ICDAS II and radiological evaluation. Focussing on deep dentin lesions, values of 0.940 (ICDAS II) and 0.845 (radiology) showed high predictability with respect to the histologically observed caries extension. The present study indicates an acceptable validity of the ICDAS II criteria when applied to permanent teeth. Especially, dentin lesions can be reliably detected. Thus, ICDAS assessment provides the possibility of reducing X-ray exposure for caries detection.

Desempenho de métodos baseados em indução de fluorescência na avaliação da remoção de dentina cariada

Resumo Introdução Critérios clínicos vêm sendo utilizados para determinação da presença de tecido cariado remanescente, mas geram dúvidas, tornando-se relevante a utilização de métodos que auxiliem na determinação da presença de cárie dentária remanescente. Objetivo Avaliar in vitro a eficácia de métodos de indução de fluorescência no diagnóstico da remoção de tecido cariado artificial dentinário. Material e método O esmalte oclusal de 94 terceiros molares humanos hígidos foi removido, expondo a dentina subjacente, para indução microbiológica de lesão de cárie artificial. Após a remoção do tecido cariado induzido, o remanescente dentinário foi avaliado por dois examinadores com DIAGNOdent, DIAGNOdent pen e Quantitative Light-Induced Fluorescence (QLF). Após todas as avaliações, secções dos dentes foram observadas e fotografadas em lupa estereoscópica com 30× de aumento por um examinador independente. As imagens foram analisadas no software Image J, permitindo a quantificação de tecido remanescente em milímetros quadrados. Foi calculada a reprodutibilidade interexaminador através de coeficiente intraclasse, sensibilidade, especificidade e área sob a curva ROC, e o teste de McNemar (p<0,05) foi aplicado para comparação dos diferentes métodos. Resultado Dos 94 dentes, 51 (54,2%) apresentaram remanescente de tecido cariado. Os valores de sensibilidade, especificidade e área sobre a curva ROC foram semelhantes para os três grupos (p>0,05). Os valores de reprodutibilidade variaram entre 0,952 e 0,978. Conclusão Dentre os métodos utilizados, o DIAGNOdent e o DIAGNOdent pen apresentaram melhor desempenho na avaliação da presença de cárie artificial remanescente quando comparados ao QLF.

In vitro Detection of Occlusal Caries on Permanent Teeth by a Visual, Light-Induced Fluorescence and Photothermal Radiometry and Modulated Luminescence Methods

Background: The paradigm shift towards the nonsurgical management of dental caries relies on the early detection of the disease. Detection of caries at an early stage is of unequivocal importance for early preventive intervention. Objective: The aim of this in vitro study is to evaluate the performance of a visual examination using the International Caries Detection and Assessment System (ICDAS) criteria, two quantitative light-induced fluorescence (QLF) systems - Inspektor™ Pro and QLF-D Biluminator™ 2 (Inspektor Research Systems B.V., Amsterdam, The Netherlands) - and a photothermal radiometry and modulated luminescence, The Canary System® (Quantum Dental Technologies, Toronto, Ont., Canada) on the detection of primary occlusal caries on permanent teeth. Methods: A total of 60 teeth with occlusal surface sites ranging from sound to noncavitated lesions (ICDAS 0-4) were assessed with each detection method twice in a random order. Histological validation was used to compare methods for sensitivity, specificity, percent correct, and the area under the receiver operating characteristic curve (AUC), at standard and optimum sound thresholds. Interexaminer agreement and intraexaminer repeatability were measured using intraclass correlation coefficients. Results: Interexaminer agreement ranged between 0.48 (The Canary System®) and 0.96 (QLF-D Biluminator™ 2). Intraexaminer repeatability ranges were 0.33-0.63 (The Canary System®) and 0.96-0.99 (QLF-D Biluminator™ 2). The sensitivity range was 0.75-0.96 while that of specificity was 0.43-0.89. The AUC were 0.79 (The Canary System®), 0.87 (ICDAS), 0.90 (Inspektor™ Pro), and 0.94 (QLF-D Biluminator™ 2). Conclusion: ICDAS had the best combination of sensitivity and specificity followed by QLF-D Biluminator™ 2 at optimum threshold.

Evaluating performance of dental caries detection methods among third-year dental students

Background

Reliable caries detection is a cornerstone in the modern caries treatment schema. This study aimed to evaluate adopting traditional and new caries detection methods by third-year dental students.

Methods

Fifty-seven students were given lectures on caries detection, after which they evaluated 27 extracted carious teeth using traditional clinical assessment (CE), Nyvad’s, and ICDAS methods. On three teeth they also performed DIAGNOdent pen® (LF) scanning. Histological scores of the sectioned teeth (ICDAS, LF) and activity estimations of the lesions by the supervisors were used as golden standards (Nyvad, CE). For the ICDAS method , sensitivity and specificity were calculated using dentine caries (D3) as a cut-off point. Mean ICC and kappa values were calculated to evaluate interexaminer agreement for all lesions and methods. Spearman’s correlation coefficient evaluated LF scanning.

Results

ICDAS method presented good sensitivity (0.78) and specificity (0.87). The inter-examiner agreement for different methods was fair or good (CE ICC = 0.69, κ = 0.53; Nyvad’s method ICC = 0.68, κ = 0.48, ICDAS ICC = 0.66, κ = 0.47). Variation in LF values was the greatest with lesions extending to middle third of dentin. In that case, the Spearman’s correlation coefficient was also the weakest.

Conclusions

To follow the guidelines by the European Core Curriculum on Cariology, the third year dental students are introduced to methods for detecting lesion depth and assessing lesion activity as well as using new caries detection methods. Their performance in estimating lesion depth is good, and fair to good in estimating lesion activity even after basic training only.

Adjunct methods for caries detection: a systematic review of literature

OBJECTIVE

To assess the diagnostic accuracy of adjunct methods used to detect and quantify dental caries.

STUDY DESIGN

A systematic literature search for relevant papers was conducted with pre-determined inclusion and exclusion criteria. Abstracts and full text articles were assessed independently by two reviewers. The study characteristics were compiled in tables and quality graded according to the QUADAS tool. The level of evidence for each diagnostic technology (fiber-optic methods, fluorescence methods, electrical methods) was based on studies of high or moderate quality according to the GRADE approach.

RESULTS

Twenty-five reports fulfilled the inclusion criteria. One study was of high quality, 10 were graded as moderate, while the remaining 14 reports were of low quality. Electrical methods (ECM) and laser fluorescence (DIAGNOdent) displayed sensitivities and specificities around 70-80% regarding occlusal dentin lesions with a mean Youden's index of 0.52-0.54. The mean accuracy of laser fluorescence for detecting enamel and dentin lesions was 0.68 and 0.91, respectively. The heterogeneity of the published reports hampered the analysis.

CONCLUSIONS

There was insufficient scientific evidence for diagnostic accuracy regarding fiber-optic methods and quantitative light-induced fluorescence (+OOO). The electrical methods and laser fluorescence could be useful adjuncts to visual-tactile and radiographic examinations, especially on occlusal surfaces in permanent and primary molars, but evidence was graded as limited (++OO). No conclusions could be drawn regarding the cost-effectiveness of the methods. There is an obvious need to standardize study designs for in vitro and in vivo validation of the different methods.

Irregularities below the enamel-dentin junction may predispose for fissure caries

This study investigated the structure of the fissure fundus on occlusal surfaces with respect to the detection of possible irregularities below the enamel-dentin junction (EDJ). Occlusal surfaces were examined by micro-computed tomography (µCT). In total, 203 third molars with clinically sound occlusal fissures or non-cavitated lesions were selected. All specimens were scanned with µCT. Subsequently, each tooth was sectioned, and each slice was investigated by stereomicroscopy. In 7 of 203 molars (3.4%), demarcated radiolucencies below the EDJ were detected by µCT. These defects were obviously of non-carious origin, because the µCT images revealed no gradient of demineralization in the dentin. In all cases, a direct pathway between the oral cavity and the dentin was evident. The comparison of the µCT sites with conventional histological images also revealed defects in the dentin. These results demonstrate that demarcated radiolucencies below the EDJ may not necessarily be caries lesions according to µCT images and may be classified as possible developmental irregularities. To avoid misinterpreting µCT data, dental researchers should carefully consider this condition when analyzing µCT images. The clinical significance of this finding is that these defects may predispose molar teeth to early-onset caries in occlusal pits and fissures.