What imaging modalities are recommended for evaluating dental caries?

Imaging Modalities for Dental Caries Evaluation

Bitewing radiography is the primary radiographic examination of choice for detecting dental caries in both primary and permanent teeth, with periapical radiographs indicated as supplementary imaging for high caries risk patients or when pulpal involvement is suspected. 1

Primary Diagnostic Approach

Visual Examination

• Visual inspection serves as the initial assessment method for dental caries, particularly in primary dentition 1
• Special consideration for dentition types:
  • Direct visualization of interproximal contact areas may be sufficient without radiographs 1
  • Areas where direct visualization is not possible require radiographic assessment

Radiographic Examination

1. Bitewing Radiography

   • First-line radiographic method for caries detection in both primary and permanent teeth 1
   • Provides adequate visualization of the entire crown of permanent teeth 1
   • Superior sensitivity compared to visual examination alone for occlusal caries 2
   • When combined with visual examination, correctly classifies 82% of first permanent molars and 91% of second primary molars 2

2. Periapical Radiography

   • Indicated as a supplementary examination for:
     • High caries risk patients 1
     • Suspected pulpal or apical involvement 1
     • Should be taken using paralleling technique with film holders and beam aiming devices 1

Patient Risk Assessment Considerations

The radiographic approach should be tailored based on caries risk assessment:

• High caries risk patients:

  • More aggressive diagnostic approach with radiographs 1
  • Combination of bitewing and periapical radiographs often indicated 1
  • Follow-up radiographs at appropriate intervals

• Low to moderate risk patients:

  • Visual examination may be sufficient for accessible surfaces 3
  • Bitewing radiographs as needed for interproximal areas

Special Clinical Scenarios

1. Suspected pulpal involvement:

   • Periapical radiographs using paralleling technique 1
   • Particularly important for high caries risk patients 1

2. Presence of fistula:

   • Intraoral radiograph with gutta-percha cone inserted into fistula 1

3. Recurrent caries under restorations:

   • Bitewing radiographs are essential as visual inspection alone has limited agreement (Kappa=0.19) with radiographic findings 4
   • Restorations with established and active lesions at margins have higher likelihood of recurrent caries on radiographs 4

Advanced Imaging Modalities

1. Cone Beam Computed Tomography (CBCT):

   • Not recommended as first-line examination for caries detection 1
   • Should be limited to suspect or unclear cases after traditional intraoral examination 1
   • Can better highlight periapical disease but at higher radiation dose 1

2. Non-radiographic adjunct methods:

   • Fiber-optic transillumination (FOTI) may aid the diagnostic process 1, 5
   • FOTI shows comparable accuracy to detailed visual inspection for occlusal caries 5
   • Near-infrared light transillumination (NIR-LT) provides limited additional diagnostic benefit (6.8%) beyond visual inspection 6

Clinical Pitfalls and Caveats

• Radiographic examination alone has limitations in detecting early enamel lesions 5
• Superimposition of bony structures in posterior areas may obscure periapical pathology 1
• Laser fluorescence and similar technologies are not currently viable alternatives to radiographic diagnostics due to insufficient scientific evidence 1
• Radiation protection (thyroid collar) should be used, especially for pediatric patients 1
• Combining visual inspection with radiographs provides the most accurate assessment 2, 3

Diagnostic Algorithm

1. Begin with thorough visual examination of all accessible surfaces
2. For patients with suspected caries:
   • Obtain bitewing radiographs as primary radiographic method
   • Add periapical radiographs if patient is high-risk or pulpal involvement is suspected
3. Consider adjunctive methods (FOTI, NIR-LT) for specific clinical situations where additional information is needed without radiation exposure
4. Reserve CBCT only for cases where standard radiographs are inconclusive and additional information is critical for treatment planning