Case Model 3
Monitoring vs Intervention — Early Crack Under High Force
Case Summary
Mandibular molar
Small occlusal composite
Visible superficial crack line on mesiobuccal cusp
No fracture
No radiographic pathology
Patient reports heavy clenching
Noticeable occlusal wear
No spontaneous pain
1. Structure Assessment
Superficial crack line present
Marginal ridges intact
Dentin thickness adequate
No cusp undermining
Periodontal support intact
Structural reserve: Moderate to High
Crack presence introduces localized structural vulnerability but does not yet compromise overall geometry.
2. Force Assessment
Heavy clenching reported
Occlusal wear evident
Lateral contact present on affected cusp
No protective appliance use
Force risk: High
Projected cyclic loading significant.
3. Time Projection
Crack likely fatigue-related
Ongoing parafunctional activity
No behavioral modification in place
Projected continued heavy loading
Time risk: High
Crack propagation likely to progress under continued force exposure.
4. Long-Term Stability Projection
Under Monitoring Only
Crack may propagate under high cyclic force
Increased risk of cusp fracture over projected time
Structural reserve likely to decline progressively
Under Escalation (Cuspal Coverage + Force Management)
Additional structural reduction required
Flexural strain reduced
Crack propagation stabilized
Long-term stability improved under projected force
5. Threshold Position
Projected force across projected time approaches or exceeds localized structural tolerance.
Structural reserve overall moderate, but crack + high force + projected time create convergence.
Threshold position: Approaching convergence with high risk of progression.
Decision:
Intervention indicated if force cannot be reduced.
If patient adopts force mitigation (occlusal guard, behavioral modification), short-term monitoring acceptable with strict reassessment.
This case demonstrates: Threshold is dynamic. Force and time can shift convergence without dramatic structural loss.