Assessement of root canal system apical region: an imaging study

Author(s)

Natália Siqueira Lobo

• Document type: Master's Dissertation
• Press: Piracicaba, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Faculdade de Odontologia de Piracicaba
• Defense date: 2020-02-17

Examining board members

Alexandre Augusto Záia; Marina Angélica Marciano; Clarissa Teles Rodrigues

• Advisor: Alexandre Augusto Záia

Abstract

The aims of this study were: 1) to assess the prevalence of ramifications in the apical region of root canals from different dental groups; 2) to compare three image methods on the detection of apical ramifications; and 3) to assess the sealing of root canal system apical region after shaping at different working lengths. For this purpose, periapical radiograph, cone-beam computed tomography (CBCT), microcomputed tomography (micro-CT) and nanocomputed tomography (nano-CT) were used. Micro-CT was used to scan 475 anterior and posterior dental roots to verify the prevalence of apical ramifications (AR). AR were present in 253 roots (53.3%). The single-rooted maxillary premolars had the greatest prevalence (83.3%), and the maxillary incisors the lowest (17.2%). To compare the image methods on the detection of AR (periapical radiograph in 1- and 2-incidences and CBCT), 160 teeth scanned in the micro-CT were established as reference standard. It was observed that CBCT shows higher accuracy in detecting ramifications even when two incidences of periapical radiographs are acquired (p>0.05). The apical sealing of the root canal system was evaluated using 22 premolars, equally divided into two groups: group 1 (G1) - root canals shaped 1 mm short of the apical foramen; and group 2 (G2) - root canals shaped at the level of the apical foramen. After endodontic treatment, nano-CT images were acquired and the sealing of root the apical region and ramifications were evaluated. G2 filled a greater volume of the main canal when compared to G1 (p<0.05), however, there was no significant difference for the filling of root canal ramifications between groups (p>0.05). Moreover, in both groups, ramifications were underfilled in comparison to the main canal (p<0.05). It was concluded that: 1) the prevalence of AR is considerably high; 2) The acquisition of periapical radiograph in 2-incidences did not improve the diagnostic accuracy of this imaging method, and CBCT was superior in identifying AR; and 3) The working length set at the level of the apical foramen allowed greater sealing of the main canal, however both working lengths presented a sub-optimal filling of ramifications (AU)

• FAPESP's process: 17/05391-9 - Incidence of ramifications located in the apical 3 mm of the root with the use of digital periapical radiography, CBCT and computerized microtomography
• Grantee: Natália Siqueira Lobo
• Support Opportunities: Scholarships in Brazil - Master