Secondary caries in restorations refers to decay that develops around the margins or beneath dental restorations and is often not directly visible during clinical examination. Early detection of secondary caries is essential to prevent restoration failure and damage to the supporting tooth structures. Digital bitewing radiography is one of the most widely used methods for diagnosing proximal caries and can also assist in detecting secondary caries around restorations. This method offers greater convenience, improved image resolution, and lower radiation exposure compared to conventional radiography, when performed with proper technique and protection.
Key Findings
Based on a narrative review published in Jurnal MKGK FKG UGM by Lathifa Dewanti Nugroho (a student at FKG UGM), under the supervision of drg. Ryna Dwi Yanuaryska, Ph.D., and Dr. drg. Rini Widyaningrum, M.Biotech., bitewing radiography is described as the standard method for detecting proximal caries due to its ability to image the crowns of teeth from the distal surface of the canine to the distal surface of the most posterior molar without overlap. Supporting technologies such as Near-Infrared Light Transillumination (NILT) were also reviewed as alternatives. The review notes that although NILT has advantages—such as higher sensitivity in detecting early-stage demineralization and the absence of ionizing radiation—bitewing radiography remains necessary as the standard, particularly for detecting deeper proximal caries or caries beneath restorations, including secondary restorations.
Advantages and Limitations of Digital Bitewing Radiography in Secondary Caries
Advantages
- Resolution & Detail
Digital radiography allows image magnification and reveals subtle differences in radiopacity at restoration margins and surrounding tissues. - Ease of Storage & Access
Digital images are easier to store, share, and compare during follow-up visits. - Relatively Lower Radiation Dose
With digital sensors and optimal exposure settings, digital bitewing radiography can minimize X-ray exposure in accordance with the ALARA (As Low As Reasonably Achievable) principle. - Diagnostic Standard
Because bitewing radiography has long been the standard for detecting proximal caries and restoration-related issues, extensive comparative literature is available, making interpretation more reliable.
Limitations
- Difficulty in detecting very deep caries or caries beneath metal restorations that cause artifacts or block X-rays.
- Overlapping teeth or restoration positioning can complicate interpretation of secondary caries.
- Strong dependence on imaging technique: patient positioning, sensor placement, exposure settings, and equipment quality significantly affect results.
- Radiation risk, although minimal, still exists if examinations are frequently repeated.
Clinical Recommendations
- Use digital bitewing radiography as the first-line or routine method in periodic examinations of restorations, especially for contact restorations or margins suspected of early deterioration.
- Combine visual examination, digital radiography, and non-radiation methods such as NILT (if available) to improve early detection.
- Ensure proper imaging technique: sensitive digital sensors, appropriate exposure, and correct patient and sensor positioning to minimize overlap and artifacts.
- Apply the ALARA principle to keep radiation exposure as low as possible, especially in pediatric patients or cases of repeated restorations.
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Digital bitewing radiography remains the standard for detecting proximal caries and secondary restorations. Although non-radiation methods such as NILT offer advantages in sensitivity and safety, bitewing radiography provides superior penetration for restorations and deeper carious lesions and is widely available. The combination of methods, optimal technique, and digital technology can improve detection, efficiency, and clinical outcomes of restorations.
References
MKGK, Lathifa Dewanti Nugroho, drg. Ryna Dwi Yanuaryska, Ph.D., Dr. drg. Rini Widyaningrum, M.Biotech., Deteksi karies proksimal menggunakan radiografi bitewing dan near-infrared light transillumination, https://jurnal.ugm.ac.id/mkgk/article/download/100770/40270
Author: Rizky B. Hendrawan | Photo: Freepik
