Association between Intracanal Medicament Radiopacity and Streak Artifact Production Using Cone-beam Computed Tomography: A Laboratory Study.

Introduction: This study aimed to calculate the correlation between the radiopacity levels of various intracanal medicaments and radiolucent streak formation using cone-beam computed tomography (CBCT).

Methods: Seven commercially-available intracanal medicaments were tested, which contained different amounts of radiopacifier [Consepsis, Ca(OH), UltraCal XS, Calmix, Odontopaste, Odontocide, and Diapex Plus]. Their radiopacity levels were measured according to the International Organization for Standardization 13116 testing standards (mmAl). Subsequently, the medicaments were placed in 3 canals of radiopaque artificial printed maxillary molars (n = 15 roots per medicament), leaving the second mesiobuccal canal empty. CBCT imaging was carried out using an Orthophos SL 3-dimensional scanner under recommended manufacturer exposure settings. Radiopaque streak formation was assessed by a calibrated examiner using a previously published grading system (0-3). The Kruskal-Wallis and Mann-Whitney U tests with and without Bonferroni correction were used to compare radiopacity levels and radiopaque streak scores for the medicaments. Their relationship was assessed using the Pearson correlation coefficient. The level of significance was set as (α = 0.05).

Results: Diapex plus presented with the highest radiopacity levels (4.98 ± 0.01) and radiopaque streak scores [middle third (2.8 ± 0.18); apical third (2.73 ± 0.43)]; which was similar to UltraCal XS's radiopaque streak scores [middle third (2.8 ± 0.92); apical third (2.73 ± 0.77)]. Consepsis had the lowest radiopacity levels (0.12 ± 0.05), followed by Odontocide (0.60 ± 0.05). Consepsis and Ca(OH) were scored 0 for artifacts in all roots at all levels. A high positive correlation (R = 0.95) was found between radiopacity and streak formation.

Conclusions: The radiopacity of intracanal medicaments varies and strongly correlates with the formation of radiolucent streak artifacts during CBCT.