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Year : 2019  |  Volume : 8  |  Issue : 1  |  Page : 38-41

Detection of proximal caries with digital intraoral bitewing radiography: An interobserver analysis

Restorative Dentistry Department, Faculty of Dentistry, King Abdul Aziz University; Operative Dentistry Division, Dentistry Program, Batterjee Medical College for Science and Technology, Jeddah, Kingdom of Saudi Arabia

Date of Web Publication16-May-2019

Correspondence Address:
Dr. Basem M Abuzenada
Faculty of Dentistry, King Abdul Aziz University, Jeddah
Kingdom of Saudi Arabia
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/sjhs.sjhs_141_18

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Objectives: The present study was undertaken to analyze bitewing digital images detection of interproximal caries through interobserver agreement. Materials and Methods: The study evaluated 152 bitewing radiographs for detection of interproximal caries by two observers: an operative dentist and oral radiologist. Results: The Kappa values for interobserver agreements were 0.47 and 0.44 in the first and second observations, while for intraobserver agreements, these values were 0.61 and 0.69 for the operative dentist and oral radiologist, respectively. Comparison of area under the receiver operating characteristic curves for inter- and intra-observer ratings was nonsignificant. Conclusion: The digital bitewing radiography resulted in no variation in both the agreements, and it was useful with respect to the reliability of diagnosis of interproximal caries.

Keywords: Bitewing radiographs, diagnostic accuracy, digital radiography, proximal caries

How to cite this article:
Abuzenada BM. Detection of proximal caries with digital intraoral bitewing radiography: An interobserver analysis. Saudi J Health Sci 2019;8:38-41

How to cite this URL:
Abuzenada BM. Detection of proximal caries with digital intraoral bitewing radiography: An interobserver analysis. Saudi J Health Sci [serial online] 2019 [cited 2022 Oct 7];8:38-41. Available from: https://www.saudijhealthsci.org/text.asp?2019/8/1/38/256781

  Introduction Top

Dental caries is the most prevalent chronic disease worldwide and its diagnosis remains a major challenge in clinical dentistry. Clinical examination with probing, visual inspection along with intraoral films, and digital radiography are various methods used for detection of carious lesions, yet, 25%–42% of carious lesions remain undetected.[1],[2] The current understanding about the biological concept of caries involves new methodologies in caries detection, assessment, and management including noncarious lesions.[3] Nevertheless, proximal areas can hardly be evaluated directly; decays in these surfaces are often diagnosed with the help of radiography,[1] especially bitewing radiography.

Numerous systems for intraoral digital radiography are available as alternatives to film-based radiography. With the advances in digital radiography, in view of its advantages such as image storage, ease of image manipulation, image enhancement, and ease of transfer for referral, it has more potential in adding to the quality of dental practice.[4],[5] Further diagnostic accuracy in the detection of interproximal caries on digital intraoral radiography is considered equivalent to film-based radiography.[6]

Thus, analysis of retrospective data in understanding the diagnostic importance of direct digital images and its futuristic scope in enhancing the quality of rendering service to patients could be imperative. With this view in mind, the present study was undertaken, wherein digital images were analyzed for detection of interproximal caries and evaluated on the basis of interobserver agreement.

  Materials and Methods Top

Our study used 152 digital bitewing radiographs of molars and premolars. The radiographs were obtained on a Sirona Sidexis digital imaging system [Figure 1]. Radiographic exposure was performed on the VarioDG intraoral X-ray machine (Sirona, Germany). The pretreatment images of the patients were selected from the software database for evaluation after ensuring optimal image quality with good visibility of the coronal pulp, enamel, and dentin. All images were evaluated at 2-week interval separately by two calibrated observers, operative dentist, and oral radiologist without any time constraints. The mesial and distal aspects of the teeth in each image were randomly evaluated for the presence/absence of proximal caries. The scoring system was designated as a 5-point scale as, 1 – Definitely no caries, 2 – Caries likely to be absent, 3 – Questionable, 4 – Caries likely to be present, and 5 – Definite presence of caries. Observers did not have any clinical information about the absence or presence of caries and used the same monitor for evaluation.
Figure 1: An image of bitewing radiographs

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Statistical analysis

Interobserver agreement was determined with Kappa values according to Landis and Koch.[7] Kendall's correlation coefficient was calculated to measure the strength of relationships between the variables. One-way analysis of variance (ANOVA) was employed to analyze the differences of significance among inter- and intra-observer. Repeated-measure ANOVA was performed to test the variables containing the different evaluations for caries ratings by both the observers. The significance level was considered at P < 0.05.

  Results Top

Interobserver agreement was in the range of “moderate” values for interobserver evaluations, while the intraobserver agreement was found to be “substantial” [Table 1] and [Table 2]]. Kendall's correlation coefficient was significant in both the ratings [Table 2]. With the first evaluation by the oral radiologist as a reference standard, each performance was subsequently converted into a receiver operating characteristic (ROC) curve. The maximum likelihood parameters were determined and the area under each ROC curve (Az) was calculated. [Table 3] shows that area under the ROC curve for each observation, but no significant difference was found between inter- and intra-observer performances [Figure 2].
Table 1: Strength of agreement according to kappa value by Landis and Koch[7]

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Table 2: Interobserver agreement for the assessment of proximal caries on bitewing radiographs

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Table 3: Comparison of area under the receiver operating characteristic curves for inter- and intra-observer ratings

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Figure 2: Receiver operating characteristic curves for both the observers

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[Table 4] shows the mean and standard deviations for each observation by both the observers. Significant differences in their means were found in one-way ANOVA and repeated measure ANOVA among all the observations.
Table 4: Oneway and repeated-measure analysis of variance for comparison of observer's ratings

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  Discussion Top

It is imperative to detect caries as timely as possible to reverse/stop its progression where ever possible and to restore the tooth in a most conservative way.[8] The diagnostic accurateness of frequently used methods needs a comprehensive evaluation to differentiate among their advantages and limits.[9] Nevertheless, accurate caries detection, especially on proximal surfaces, is essential for the management and preservation of dentition. Although numerous caries detection tools exist, none of them individually would give an accurate detection of caries. Radiography remains a routine method for the detection of dental caries and depends on the selection of radiographic technique. With the advances in digital radiography, it has been compared with conventional film-based radiography for caries diagnosis.[9],[10]

Digital radiography is one of encouraging tool in diagnosis and detection of dental caries. The diagnostic performance of digital radiographs is as good as conventional radiographs. In addition, it needs low radiation dose and the images can be archived and replicated with ease.[11] Most of the clinicians nowadays prefer digital radiography over conventional radiography due to its ease of operation. However, there is a need to understand other potential advantages of digital radiography such as the use of color coding and other image enhancing tools. Thus, there is a need for new generation general dentists to explore the various aspects of digital radiography. Further, it was found that there are numerousin vitro studies conducted on diagnostic accuracy of digital radiography in caries detection, and very few arein vivo studies. This perpetrated the thought of evaluating the diagnostic accuracy of digital radiographs. With this view, the present study was conducted on 152 digital bitewing radiographs for the detection of proximal carious lesions. Two observers, namely, an operative dentist and the oral radiologist, evaluated those radiographs for the presence or absence of caries on the proximal surfaces.

The present study did not show significant differences among observers though intraobserver ratings were comparable. Further, observers' agreements reported in the literature also vary among radiographic studies of caries detection. This may be attributed to differences in characteristics of samples in the studies, such as depth of proximal caries, clinical presentation of dentition, tooth surface involvement, caries prevalence rate, and to some extent to the number of raters.[12],[13],[14],[15],[16]

Diagnosing a disease entity is a cognitive and perceptional phenomenon and can affect the outcomes of research studies. Expertise in visual domains like radiographic evaluations appear elusive therefore relying on a single method of diagnosis is not recommended. There is a large perceptual component in the radiographic examination that rapidly recognizes patterns rather than a cognitive component that seeks data for further judgment.[17],[18] This entails the diagnosticians to correlate the clinical findings with the information gathered from other diagnostic data. Nevertheless, the present study is promising in indicating the use of bitewing radiography for detection of a proximal carious lesion.

In the present study, interobserver and intraobserver agreements were “fair” and “substantial,” respectively. Kendall's correlation coefficients were also statistically significant suggesting good reliability. Our findings were in accordance with a study on the detection of proximal caries using direct digital radiography by Naitoh et al.[6] Rockenbach et al. also found good reliability in Kendall's coefficients in digital over conventional radiographic analysis.[5] Senneby et al. found a novel caries classification and evaluated proximal carious lesions among different observers.[18] Their interrater and intrarater agreements were found to be substantial. This reveals that digital radiography offers a better evaluation of proximal caries with experience irrespective of dental specialty and does not present a problem in relation to the reliability of diagnosis.

Both the observers' assessments were compared to determine the diagnostic performance. The diagnostic performance was expressed in terms of area under the ROC curve (AZ). No significant differences were observed in the area under curves for all observations in ROC curve analysis in this study. Similarly, other researchers found no significant differences in AZ values in various digital radiographic systems for carious lesions.[2],[5] However, some authors found significant AZ values in digital bitewing radiography.[4],[19] One study evaluated the performance of RVGui sensor and Kodak Ektaspeed film in the detection of proximal caries and found nonsignificant differences among observers.[20] Thus, it can be determined that observer agreement does not alter during multiple evaluations of the same digital data.

Evidence-based diagnosis and treatment planning necessitate a diagnostic evaluation method as precise as possible to disclose the status of the disease, lesion, or entity.In vitro studies conducted on diagnosis of proximal caries have revealed that intraoral digital radiograph bears the same diagnostic significance as that of the conventional films.[21] However, there is no correlation ofin vitro conditions that depict actual orin vivo presentation of carious lesions. Therefore, there is a need for conducting morein vivo studies to establish the promising role of diagnostic tools in the assessment of proximal carious lesions.

  Conclusion Top

The present study reveals that digital bitewings radiographs can be a useful tool in the diagnosis of proximal caries because of the advantages offered by digital systems. However, clinical correlation with radiographic images is warranted in the routine clinical practice.


The author would like to thank Dr. Harshkant Gharote, Professor of Dentistry, Batterjee Medical College, Jeddah, for participating as oral radiologist observer in this study.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Qu X, Li G, Zhang Z, Ma X. Detection accuracy ofin vitro approximal caries by cone beam computed tomography images. Eur J Radiol 2011;79:e24-7.  Back to cited text no. 1
Shi XQ, Li G. Detection accuracy of approximal caries by black-and-white and color-coded digital radiographs. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2009;107:433-6.  Back to cited text no. 2
Gomez J. Detection and diagnosis of the early caries lesion. BMC Oral Health 2015;15 Suppl 1:S3.  Back to cited text no. 3
Kamburoglu K, Kolsuz E, Murat S, Yüksel S, Ozen T. Proximal caries detection accuracy using intraoral bitewing radiography, extraoral bitewing radiography and panoramic radiography. Dentomaxillofac Radiol 2012;41:450-9.  Back to cited text no. 4
Rockenbach MI, Veeck EB, da Costa NP. Detection of proximal caries in conventional and digital radiographs: Anin vitro study. Stomatologija 2008;10:115-20.  Back to cited text no. 5
Naitoh M, Yuasa H, Toyama M, Shiojima M, Nakamura M, Ushida M, et al. Observer agreement in the detection of proximal caries with direct digital intraoral radiography. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1998;85:107-12.  Back to cited text no. 6
Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics 1977;33:159-74.  Back to cited text no. 7
Parveen K, Wyne AH. Methods for caries detection: An overview. Pak Oral Dent J 2015;35:666-9.  Back to cited text no. 8
Nuvvula S, Bhumireddy JR, Kamatham R, Mallineni SK. Diagnostic accuracy of direct digital radiography and conventional radiography for proximal caries detection in primary teeth: A systematic review. J Indian Soc Pedod Prev Dent 2016;34:300-5.  Back to cited text no. 9
[PUBMED]  [Full text]  
Sousa Melo SL, Belem MD, Prieto LT, Tabchoury CP, Haiter-Neto F. Comparison of cone beam computed tomography and digital intraoral radiography performance in the detection of artificially induced recurrent caries-like lesions. Oral Surg Oral Med Oral Pathol Oral Radiol 2017;124:306-14.  Back to cited text no. 10
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Wenzel A. Computer-automated caries detection in digital bitewings: Consistency of a program and its influence on observer agreement. Caries Res 2001;35:12-20.  Back to cited text no. 12
Wenzel A, Hintze H, Kold LM, Kold S. Accuracy of computer-automated caries detection in digital radiographs compared with human observers. Eur J Oral Sci 2002;110:199-203.  Back to cited text no. 13
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Norman GR, Coblentz CL, Brooks LR, Babcook CJ. Expertise in visual diagnosis: A review of the literature. Acad Med 1992;67:S78-83.  Back to cited text no. 17
Senneby A, Elfvin M, Stebring-Franzon C, Rohlin M. A novel classification system for assessment of approximal caries lesion progression in bitewing radiographs. Dentomaxillofac Radiol 2016;45:20160039.  Back to cited text no. 18
Tyndall DA, Ludlow JB, Platin E, Nair M. A comparison of Kodak ektaspeed plus film and the Siemens sidexis digital imaging system for caries detection using receiver operating characteristic analysis. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1998;85:113-8.  Back to cited text no. 19
Abreu M Jr., Mol A, Ludlow JB. Performance of RVGui sensor and Kodak ektaspeed plus film for proximal caries detection. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2001;91:381-5.  Back to cited text no. 20
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  [Figure 1], [Figure 2]

  [Table 1], [Table 2], [Table 3], [Table 4]


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