Likelihood of Cavitation Based on Radiographic Depth of Carious Lesions
I cannot identify a specific paper in the provided evidence that reports the exact percentages you mentioned (R0 = 0%, R1 = 0-10%, R2 = 10-20%, R3 = 30-40%, R4 = 40-50%, R5 = very likely) for cavitation likelihood based on radiographic depth classifications R0 through R5.
What the Available Evidence Shows
The most relevant study examining cavitation likelihood by radiographic depth is from an Indian population, which found substantially different thresholds than traditional Western guidelines 1.
Cavitation Rates by Radiographic Depth
The available research provides the following data on cavitation likelihood:
- Enamel lesions (Score 1): Cavitated in 25.6-38.3% of cases, depending on the observer 1
- Outer dentinal lesions (Score 2): Cavitated in 83.3-100% of cases 1
- Inner dentinal lesions (Score 3): Cavitated in 96.4-100% of cases 1
Important Population-Specific Variations
A critical caveat is that cavitation thresholds vary significantly by population 1. The Indian population study demonstrated that radiographically shallow carious lesions were often cavitated, with 80-100% of outer dentinal lesions leading to false non-operative treatment decisions when Western guidelines were applied 1. This suggests the threshold for cavitation should be set between enamel and outer dentine in some populations, rather than at the traditional deeper level 1.
Radiographic Depth and Bacterial Penetration
More recent evidence establishes clear associations between radiographic depth and pulpal involvement:
- Deep lesions (≥3/4 dentine thickness with radio-dense zone): Bacteria typically remain in primary dentine only 2
- Extremely deep lesions (entire dentine thickness, no radio-dense zone): Bacteria frequently contact pulpal tissue (OR = 6.84,95% CI [2.00,62.83]), with associated inflammatory infiltrate and partial pulp necrosis 2
Clinical Implications
The major limitation of bitewing radiography is that it cannot directly determine surface cavitation status—only lesion depth, which is then used to predict cavitation 3. Current guidelines recommend operative intervention when lesions extend more than one-third into dentine radiographically, though this threshold remains controversial and may require adjustment based on population characteristics 3.
For clinical decision-making, direct visual examination after tooth separation remains the gold standard for determining cavitation status 4, 1. When lesions appear non-cavitated clinically or restricted to enamel by fiber-optic transillumination or radiography in low caries prevalence populations, a preventive approach should be adopted 4.