In Vitro Evaluation of Reliability and Validity of International Caries Detection and Assessment System II Coding for Occlusal Caries using Magnification
Corresponding Author: Kakarla Sri RojaRamya, Department of Pediatric Dentistry, Vishnu Dental College, Bhimavaram, Andhra Pradesh, India, Phone: +91 8985774540, e-mail: firstname.lastname@example.org
Aim: To check the reliability and validity of International Caries Detection and Assessment System (ICDAS) II coding in occlusal caries detection under unaided visual and enhanced visual examination.
Materials and methods: This study included 100 extracted premolars and molars. Two examiners independently scored occlusal caries using ICDAS II criteria without magnification and under 6x magnification in the dental operating microscope. The examination was repeated after one month to check the intraexaminer reliability. The examined samples were sectioned and the carious lesions were scored using Ekstrand–Ricketts–Kidd (ERK) histological criteria under 20x magnification in stereomicroscope. The ICDAS II scores given by the examiners were compared with the histological scores.
Results: The κ values for interexaminer reproducibility of unaided and enhanced visual examinations were 0.695 and 0.626, respectively (substantial agreement), and 0.984 (almost perfect agreement) for histological examination. Intraexaminer reproducibility for unaided and enhanced visual examinations were 0.835 and 0.910, respectively (almost perfect agreement). Spearman’s correlation coefficients of ICDAS II unaided visual and enhanced visual examinations to ERK histological scores were 0.724 and 0.689, respectively, which infers that there is a strong correlation between unaided visual and histological examination and a moderate correlation between enhanced visual and histological examination. For unaided visual examination, specificity is 100% and sensitivity is 92%, whereas for enhanced visual examination, specificity is 50%, and sensitivity is 100%.
Conclusion: Unaided visual examination demonstrated good reliability and validity for ICDAS II coding, whereas enhanced visual examination exhibited good reliability but relatively lower validity.
Clinical significance: This study reveals that magnification did not have any added benefits in occlusal caries diagnosis using ICDAS II coding compared to unaided visual examination. The use of magnification did not improve the validity and led to a drop in the specificity, which indicates higher chances of false positive results.
How to cite this article: SasiRekha G, Chandrasekhar R, Vinay C, et al.In Vitro Evaluation of Reliability and Validity of International Caries Detection and Assessment System II Coding for Occlusal Caries using Magnification. Int J Clin Pediatr Dent 2023;16(S-2):S138–S141.
Source of support: Nil
Conflict of interest: None
Keywords: Enhanced visual examination, International Caries Detection and Assessment System II coding, Occlusal caries, Reliability, Sensitivity, Specificity, Unaided visual examination
Occlusal surfaces of teeth are most commonly affected by dental caries because of their complex morphology. Most of the initial occlusal caries remain undiagnosed or misdiagnosed because of stains in pits and fissures. Carious lesions, if diagnosed in the early noncavitated stages, remineralization can be encouraged, and thereby the tooth structure can be preserved. Diagnosing dental caries in the initial stage allows the clinician to implement effective management strategies. The need for the identification of activity, severity, and clinical staging of dental caries is of paramount importance in the deployment of treatment strategies.
There is a strong need to record noncavitated lesions to practice minimal intervention in caries management. In this pursuit, the ICDAS came into the profile. ICDAS I was developed in 2002 and later modified to ICDAS II in 2005.1 This system helps in detecting the caries process at every stage and obtaining quality information for better diagnosis.2
Subjective interpretation of visual examination and tactile sensation using a mouth mirror and probe is the basis for caries detection in the routine examination. But the exact depth of the lesion can’t be estimated because forceful probing can cause damage to unsupported enamel. The need to diagnose incipient lesions and the difficulty in detecting them makes it necessary to use additional diagnostic aids such as magnification loupes or dental operating microscope (DOM).
The evidence on validation of ICDAS II criteria in diagnosing dental caries under enhanced visual examination is not clear. Hence, a study was carried out to check the reliability and validity of ICDAS II coding using enhanced visual examination in comparison with an unaided visual examination.
MATERIALS AND METHODS
This in vitro study was approved by the Institutional Ethical Review Board (VDC/IEC/2018/32). The sample size of the study was calculated to be 89 teeth based on the data from the previous study using the N power formula, keeping the power of the study 80%, α-error 5%, and a difference of 18%.3
A total of 100 premolar and permanent molar teeth with varying degrees of occlusal caries, which were extracted due to periodontal or orthodontic reasons, were collected and kept in 10% formalin solution for disinfection as per the Centers for Disease Control and Prevention guidelines.4 Teeth that underwent restoration or endodontic treatment and teeth with severe calculus in the fissures that cannot be removed were excluded from the study. Ultrasonic scaling was performed to remove hard deposits and tissue remnants on the tooth surface. Occlusal surfaces were cleaned with pumice and prophylactic brushes and rinsed under running water.
Photographs of the occlusal surfaces of all teeth were made and the area to be examined is marked on the photograph for the ease of relocation of the examination site during further examinations. The examiners were asked to assess each tooth by unaided visual examination (using dental chair light, mouth mirror, and Community Periodontal Index of Treatment Needs probe) as well as enhanced visual examination using DOM at 6x magnification (Labomed, Los Angeles, California, United States of America)
Examiners were asked to assess the extent of occlusal caries using ICDAS II criteria on a scale of 0–6. Artificial saliva was used when recording ICDAS II codes 1, 2, and 3 to view under wet conditions. During the examination, teeth were randomly given to the examiners, and the scores were recorded. In phase 1, a total of 10 samples were examined by examiner 1 under unaided visual examination and the same samples were examined by examiner 2 on the same day under enhanced visual examination using a dental operating microscope. In phase 2, to check the interexaminer reliability for unaided visual and enhanced visual examinations, examiners were asked to repeat the examinations after 5 days, but examiner 1 examined the teeth under enhanced visual examination and vice versa. To obtain intraexaminer reliability, both phase 1 and 2 procedures were carried out after a period of 1 month.
For histological examination, decoronation was done and the coronal part was sectioned through the marked investigation site with a double-faced diamond disc at a speed of 300 rpm. The sectioned samples were examined by both examiners under 20x magnification of stereomicroscope and scored according to the ERK scoring criteria.
The obtained data were statistically analyzed using Statistical Package for the Social Sciences software (version 22.0, Armonk, New York: IBM Corp.). Inter and intraexaminer agreements for ICDAS II scores were measured using Cohen’s κ statistical test. For each examiner, the relationship between the unaided visual, enhanced visual and the histological scoring system was assessed using the Spearman rank correlation. McNemar’s test was used to compare the sensitivity and specificity between examinations. The degree of agreement for unaided visual and enhanced visual examinations in comparison with the histological status was calculated using receiver operating characteristic (ROC) statistics and the area under the curve (Az) values.
The intraexaminer reliability for unaided visual as well as enhanced visual examinations was found to be in the range of almost perfect agreement indicating a high degree of consistency (Table 1).
|Mode of examination||Examiner||Cronbach’s α value|
|Unaided visual examination||Examiner 1||0.835|
|Enhanced visual examination||Examiner 1||0.910|
Cohen’s κ statistics
Interexaminer reliability for unaided and enhanced visual examinations showed substantial agreement between the two examiners. For histological examination, there is a 98% agreement, that is, almost perfect agreement (Table 2).
|Mode of examination||Cronbach’s α value|
|Unaided visual examination||0.695|
|Enhanced visual examination||0.626|
Cohen’s κ statistics
Codes recorded with unaided and enhanced visual examinations were found to be different for some teeth. Around 60% of teeth coded as no caries in the unaided visual examination were coded as ICDAS II code 1 in the enhanced visual examination. Around 40% of teeth coded as without clinical visual signs of dentinal involvement (ICDAS II code 3) in the unaided visual examination were coded as a distinct cavity with visible dentin in enhanced visual examination (ICDAS II code 5) (Table 3).
|Mode of evaluation||ICDAS II Codes|
|Unaided visual examination||12||35||26||15||2||6||4||100|
|Enhanced visual examination||4||17||29||28||1||15||6||100|
|ERK histological score||8 (code 0)||55 (code 1)||21 (code 2)||10 (code 3)||6 (code 4)||100|
On correlating the unaided, enhanced visual and histological examinations, a moderate correlation between enhanced visual and histological examination and a strong correlation between unaided visual and histological examination were observed (Table 4).
|Correlation between the modes of examination||R-value|
|Unaided visual and histological examinations||0.724|
|Enhanced visual and histological examinations||0.689|
Spearman’s correlation coefficient
On comparing the accuracies of unaided and enhanced visual examinations with histological examination, sensitivity was found to be marginally more for enhanced visual examination, whereas specificity was found to be more for unaided visual examination. McNemar’s test reported a significant difference between the sensitivity and specificity of unaided and enhanced visual examinations (Table 5). The area under the curve is found to be similar for unaided (0.962) and enhanced visual examinations (0.934) (Table 6 and Fig. 1).
|Unaided visual examination||Enhanced visual examination|
|Sensitivity||0.9239, S||1.0000, S|
|Specificity||1.0000, S||0.5000, S|
McNemars test; S, significant
|Mode of examination||Az value|
|Unaided visual examination||0.962|
|Enhanced visual examination||0.934|
|Z test–0.0768 (nonsignificant)|
Conventional methods of caries diagnosis include the visual method and the visual-tactile method. Even though the visual examination is a simple technique, it has low sensitivity and reproducibility.5 The visual-tactile method is routinely carried out in clinical practice, but it is primarily based on subjective interpretation of surface characteristics such as integrity, texture, translucency or opacity, location, and color.6
A variety of innovative techniques have been introduced in the last few decades to aid clinicians not only in early caries detection but to make a firm diagnosis and treating cases conservatively. The use of magnification amplifies vision and avails an enlarged, exaggerated and intensified view of an object.7 The advantages of DOM are that it provides much greater magnification, higher optical performance, greater depth of focus and magnification changes can be done in real-time. Consequently, the required area is well-illuminated with a shadow-free clear vision.7
Accurate caries detection and classification contribute to identifying caries risk patients, detecting enamel lesions, and planning a nonoperative treatment. ICDAS is an evidence-based system that permits standardized caries detection and diagnosis.1 ICDAS scoring criteria was developed to understand the process of caries initiation and progression, which records not only the severity but also the incidence of caries.1
In the current study, the intraexaminer reliability for both the examiners showed good reproducibility for both the unaided as well as enhanced visual examinations. Jablonski-Momeni et al. demonstrated an excellent intraexaminer agreement for ICDAS in occlusal caries detection with unaided visual and enhanced visual methods.8 Similar pattern of intraexaminer reproducibility was observed with low-powered magnification and low-powered magnification along with light emitting diode illumination in both primary and permanent molars.9 In contrast, few studies have reported low intraexaminer reproducibility values with both unaided and enhanced visual examinations.10,11
In this study, a substantial agreement was observed between the two examiners for unaided and enhanced visual examinations. This might be due to the prior training of the examiners in detecting caries using ICDAS II classification. Examiners attended a 2-hour e-learning program on the ICCMS website. Also, ten teeth with different ICDAS–II scores were given to each examiner to allow for calibration. Few other studies have also reported a substantial reproducibility for ICDAS II under unaided and enhanced visual examinations.10,12
Observations of the present study reveal that ICDAS II has good intraexaminer and acceptable interexaminer reproducibility in the diagnosis of occlusal caries under both unaided and enhanced visual examination methods. The interexaminer reproducibility for ERK histological classification in the current study is interpreted as an almost perfect agreement, which is similar to the study done by Sathyanarayanan et al.10
In the present study, a moderate correlation was found between enhanced visual examination and histological examination and a strong correlation between unaided visual examination and histological examination, which is in line with the results of the study done by Mitropoulos et al.3 In contrast, Ari et al. demonstrated that the correlation between unaided visual and histological examination was not strong.9 Whereas, Sathyanarayanan et al. reported a very strong correlation with histological examination for both the methods and for both examiners.10
In the current study, sensitivity and specificity values have shown a significant difference between unaided visual and enhanced visual examinations. The obtained sensitivity values infer that an ICDAS II criterion is a sensitive diagnostic method for occlusal caries diagnosis, irrespective of the type of vision (unaided/enhanced).
In the present study, unaided visual examination demonstrated high specificity, whereas enhanced visual examination showed low specificity. The low specificity associated with enhanced visual examination can lead to the false-positive diagnosis of noncarious surfaces. This low specificity could be attributed to the complex morphology of the groove-fossa system, which leads to staining. Similar levels of specificity were reported by Sisodia and Manjunath.13 Whereas Jablonski-Momeni et al. reported low sensitivity and high specificity levels for unaided visual examination when all the carious stages are included in the sample.8
In the present study, the area under the curve (Az) values were similar for both types of examinations. In the ROC curve, Az value weighs changes in sensitivity and specificity equally when the curve slope equals one. However, in cases of high sensitivity but low specificity, as in the present study, the ROC curve is less important because Az tends to enhance the sensitivity values. Considering Az alone without meaningful clinical information does not have much relevance.14
In summary, unaided visual examination demonstrated good reliability and validity for ICDAS II criteria and thus makes it more desirable for the detection of occlusal caries. Enhanced visual examination exhibited good reliability but relatively lower validity. The use of magnification did not improve the validity and lead to a drop in the specificity, which indicates higher chances of false positive results.
Based on the observations of the present study, the following conclusions was drawn:
International Caries Detection and Assessment System (ICDAS) II criteria was found to be a reliable diagnostic method in detecting occlusal caries under both unaided and enhanced visual examinations.
The unaided visual examination demonstrated superior validity than the enhanced visual examination.
The unaided visual examination demonstrated high specificity and sensitivity, whereas enhanced visual examination exhibited high sensitivity but low specificity.
Both unaided and enhanced visual examinations demonstrated a good correlation with the histological examination.
1. Gugnani N, Pandit IK, Srivastava N, et al. International caries detection and assessment system (ICDAS): a new concept. Int J Clin Pediatr Dent 2011;4(2):93–100. DOI: 10.5005/jp-journals-10005-1089
3. Mitropoulos P, Rahiotis C, Kakaboura A, et al. The impact of magnification on occlusal caries diagnosis with implementation of the ICDAS II criteria. Caries Res 2012;46(1):82–86. DOI: 10.1159/000335988
4. Centers for Disease Control and Prevention. Guidelines for Infection Control in Dental Health-Care Settings -- 2003. MMWR 2003;52(No. RR-17):33.
5. Braga MM, Mendes FM, Martignon S, et al. In vitro comparison of Nyvad’s system and ICDAS-II with lesion activity assessment for evaluation of severity and activity of occlusal caries lesions in primary teeth. Caries Res 2009;43(5):405–412. DOI: 10.1159/000239755
9. Ari T, Kofman SH, Ari N. In vitro evaluation of magnification and LED illumination for detection of occlusal caries in primary and permanent molars using ICDAS Criteria. Dent J 2013;1(3):19–30. DOI: 10.3390/dj1030019
10. Sathyanarayanan R, Usha C, Sudhagar R. Reliability and validity of ICDAS II coding for occlusal caries using magnification: an in-vitro study. Int J 2017;3(6):149–155. DOI: 10.18203/issn.2454-2156.IntJSciRep20172031
11. Rodrigues JA, Hug I, Diniz MB, et al. Performance of fluorescence methods, radiographic examination and ICDAS II on occlusal surfaces in vitro. Caries Res 2008;42(4):297–304. DOI: 10.1159/000148162
12. T LB, Jayadevan A, Chakravarthy D, et al. Inter examiner reproducibility in the detection of occlusal caries using international caries detection and assessment system (ICDAS) II by unaided visual and enhanced visual examination - an in vivo study. Int J Appl Dent Sci 2019;5(2):08–12.
13. Sisodia N, Manjunath MK. Impact of low level magnification on incipient occlusal caries diagnosis and treatment decision making. Journal of clinical and diagnostic research. J Clin Diagn Res 2014;8(8):ZC32–ZC35. DOI: 10.7860/JCDR/2014/8533.4742
14. Halligan S, Altman DG, Mallett S. Disadvantages of using the area under the receiver operating characteristic curve to assess imaging tests: a discussion and proposal for an alternative approach. Eur Radiol 2015;25(4):932–939. DOI: 10.1007/s00330-014-3487-0
© The Author(s). 2023 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted use, distribution, and non-commercial reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.