Geomorphologic study of human tooth root surfaces following simulated avulsion by scanning electron microscopy

Area of Science:

• Dental Traumatology
• Biomaterials Science
• Microscopy

Background:

• Tooth avulsion is a severe dental injury.
• Delayed replantation (>1 hour) leads to root surface damage, ankylosis, and tooth loss.
• Understanding ultrastructural changes is crucial for improving treatment outcomes.

Purpose of the Study:

• To investigate the geomorphologic changes on tooth root surfaces caused by dehydration.
• To explore methods for reversing dehydration-induced root surface damage.

Main Methods:

• Human premolars and molars were dehydrated for varying durations (1-24 hours).
• Root surfaces were analyzed using scanning electron microscopy (SEM).
• Acid treatments (Tris-HCl or citric acid) were applied to dehydrated samples.

Main Results:

• Dehydration (>1 hour) significantly altered root surface ultrastructure, resembling a 'Gobi Desert'.
• Fresh root surfaces exhibited fibrous "vegetation" on the cementum.
• Citric acid treatment reversed dehydration damage by exposing embedded cementum fibers.

Conclusions:

• Dehydration severely deteriorates the tooth root surface ultrastructure.
• Re-exposure of embedded cementum fibers using citric acid can reverse this damage.
• SEM provides direct evidence for improving the replantation of dehydrated avulsed teeth.