Method: Practices assessed for cracks in a posterior tooth of randomly selected subjects and subjects reporting pain symptoms. Teeth were assessed via visual examination with magnification, tactile perception and transillumination. Only cracks blocking transilluminated light were included. Various patient-, tooth-, and crack-level criteria were assessed. Various characteristics of the cracks (tooth number, location on tooth, direction, association with a restoration and its type and size, and severity of tooth wear) were assessed and correlated to the presence of symptoms. GEE logistic regression adjusted for practice was used to assess the presence of symptoms vs. covariates (p≤ 0.05).
Result: 36 practices in NW PRECEDENT evaluated 634 subjects with an eligible cracked tooth. 383 teeth (60.4%) were asymptomatic and for 251 (39.6%), pain, most commonly brief in duration and in response to biting and cold, was either reported by the patient or determined by dentist assessment. The typical crack extended onto the occlusal surface (67%) and was located on a tooth that showed wear facets (55%) and had a restoration (91%), most frequently amalgam. Among those with restorations, most cracks connected with that restoration (92%). Symptoms were significantly associated with the following characteristics: presence of any restoration (odds ratio, OR=2.31), crack located on distal, facial, or lingual surfaces (OR=2.14, 1.65, 2.07, resp.), multiple cracks (OR=2.36), crack(s) on multiple surfaces (OR=1.52), and being 18-60 years old vs. 60-90 years old (OR=2.4). There was a significant linear trend for a report of pain when a greater percent of crown/occlusal surface was restored.
Conclusion: This study shows that certain characteristics (i.e. multiple cracks on multiple surfaces, presence of restorations, age) may aid the dentist in predicting whether a tooth with a crack will become symptomatic.
Keywords: Clinical trials, Decision-making, Teeth, Trauma-fracture and Wear