A calcified root canal: can the tooth still be retained?｜證據鏈

Canal calcification or pulp-canal obliteration (PCO) is progressive hard-tissue deposition that narrows the chamber and canals. Trauma, age and chronic irritation may contribute. A canal apparently “absent” on two-dimensional radiographs may retain a fine deep path; the challenge is deciding whether intervention is needed and, if so, establishing a controlled direction while conserving tooth tissue. The first decision is not microscope, CBCT or guide selection, but the reason to treat. A review of post-traumatic PCO found watchful waiting most common in asymptomatic cases and did not recommend preventive root canal treatment. A meta-analysis of 34 studies estimated post-traumatic PCO prevalence at 27.6% in permanent and 21.9% in primary teeth; prevalence is not the proportion requiring treatment. If symptoms, examination and imaging support intervention, microscopy, limited-field CBCT, static guides or dynamic navigation may assist. Current guided-endodontic reviews mainly contain case reports, series and in-vitro studies with low, heterogeneous evidence. A recent review included only 34 case reports and 41 patients, preventing general outcome estimates or tool comparisons. Technology follows diagnosis and stopping conditions; it is not a promise.