Caries Depth Classification System

Haugejorden

D1 Outer half enamel  (< half of enamel)

D2 Inner half enamel  (>half the enamel up to ED border)

D3 Outer half dentine. Broken ED border but without obvious spread into dentine

D4 Inner half dentine  (< halfway through to pulp)

D5 Pulpal involvement  (> halfway through to pulp)

ICCMS

RA1 Radiolucency in Outer half enamel

RA2 Radiolucency in Inner half enamel +/- EDJ

RA3 Radiolucency limited to Outer third dentine

RB4 Radiolucency reaching the Middle third dentine

RC5 Radiolucency reaching the Inner third dentine, clinically cavitated

RC6 Pulpal involvement, clinically cavitated

0 No visible caries/radiolucency

International Caries Detection and Assessment System

ICDAS was developed to provide clinicians, epidemiologists and researchers with an evidence-based system, which would permit standardized caries detection and diagnosis in different environments and situations.

ICDAS is a simple, logical, evidence-based system for detection and classification of caries in dental education, clinical practice, dental research, and dental public health.

It moves the profession away from the simplistic diagnosis of "No obvious decay" or "Obvious decay" to a more detailed level of diagnosis to improve patient care and mre precisely monitor caries development in research.

Further Reading

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5030492

https://www.iccms-web.com/content/icdas