Single vs Two-session Root Canal Treatment: A Preliminary Randomized Clinical Study using Cone Beam Computed Tomography.

AIMS: To compare root canal treatment of teeth with apical periodontitis (AP) in a single or two visits, using cone beam computed tomography (CBCT).

MATERIALS AND METHODS: Twenty-six pairs of teeth (13 patients) were assigned to two groups: Group single-session (GSS): Instrumentation and root canal filling in the same session; and group two-session (GTS): A calcium hydroxide intracanal medication (Calen(®) paste) was used for 14 days between two sessions. Cone beam computed tomography scans were obtained before and 12 months after treatment. The pre- and postoperative volume of the AP lesions was measured in mm(3). The percentages of volume reduction was compared using Student's t-test and the existence of significant difference between the groups for cases with ≤ 50% or > 50% lesion volume reduction was assessed by chi-squared test ratio likelihood test (α = 5%).

RESULTS: The volume reduction was greater in GTS (79.25%) than GSS (68.35%), though without significant difference (p > 0.05). After 12 months, complete repair was not observed in any specimen. Lesion volume reduction > 50% was significantly greater with the use of an intracanal medication (p < 0.05).

CONCLUSION: Twelve months posttreatment, CBCT did not show complete repair in any of the teeth, suggesting that this follow-up period is not sufficient for complete lesion regression. In both groups, similar AP lesion volume reduction was observed after 12 months, with a more advanced repair (> 50% volume reduction) in the teeth medicated with calcium hydroxide intracanal dressing.

CLINICAL SIGNIFICANCE: Calcium hydroxide intracanal dressing provided clinical evidence to indicate its use in teeth with apical periodontitis prior to definitive root canal filling.