title: An obstruction to root canal treatment.
mesh_terms: D000328:Adult; D003784:Dental Pulp Calcification / Q000628:therapy*; D006801:Humans; D007180:Incisor / Q000293:injuries*; D008297:Male; D012390:Root Canal Therapy / Q000379:methods; D014082:Tooth Fractures / Q000628:therapy*