Enamel crack association with tooth age and wear severity: An optical coherence tomography study

To investigate the association of dental enamel cracks with estimated tooth age and varying tooth wear severities.

355 premolars were sorted from a pool of extracted human teeth, based on their estimated age range: 21-40, 41-60 years old, determined by a dental forensic method and on the presence/severity of lesions: none, mild, moderate and severe wear (Basic Erosive Wear Examination Index). The buccal and lingual surfaces of the teeth were inspected for cracks under an optical coherence tomography system. Images were evaluated according to the following scores: 0= no crack; 1= crack beginning and terminating within the enamel, not reaching the outer surface; 2= crack extending from outer enamel surface terminating within the enamel; 3= crack extending from within enamel terminating at or beyond the dentin-enamel junction (DEJ); 4= crack extending from outer enamel surface terminating at or beyond the DEJ. Data were analyzed by Spearman correlations and Mantel-Haenszel chi-square tests.

Estimated tooth age and crack score were moderately correlated. Crack scores increased between each range of estimated tooth age (P< 0.050). Occlusal surfaces showing moderate or severe wear had higher buccal crack scores than occlusal surfaces having no wear (P< 0.020) and mild wear (P< 0.001). Buccal surfaces presenting severe wear had higher buccal crack scores than buccal surfaces with no wear, mild or moderate wear (P< 0.001). Premolars having severe wear had significantly higher crack scores than premolars showing no, mild or moderate wear lesions.

Knowing that older and more severely worn teeth are more prone to enamel cracks allows clinicians to better diagnose, monitor, and prevent further damage to teeth.