Three-rooted premolar analyzed by high-resolution and cone beam CT.

OBJECTIVES: The aim of this study was to analyze the variations in canal and root cross-sectional area in three-rooted maxillary premolars between high-resolution computed tomography (µCT) and cone beam computed tomography (CBCT). MATERIALS AND METHODS: Sixteen extracted maxillary premolars with three distinct roots and fully formed apices were scanned using µCT and CBCT. Photoshop CS software was used to measure root and canal cross-sectional areas at the most cervical and the most apical points of each root third in images obtained using the two tomographic computed (CT) techniques, and at 30 root sections equidistant from both root ends using µCT images. Canal and root areas were compared between each method using the Student t test for paired samples and 95 % confidence intervals. RESULTS: Images using µCT were sharper than those obtained using CBCT. There were statistically significant differences in mean area measurements of roots and canals between the µCT and CBCT techniques (P < 0.05). Root and canal areas had similar variations in cross-sectional µCT images and became proportionally smaller in a cervical to apical direction as the cementodentinal junction was approached, from where the area then increased apically. CONCLUSION: Although variation was similar in the roots and canals under study, CBCT produced poorer image details than µCT. CLINICAL RELEVANCE: Although CBCT is a strong diagnosis tool, it still needs improvement to provide accuracy in details of the root canal system, especially in cases with anatomical variations, such as the three-rooted maxillary premolars.

Procedural errors during root canal preparation using rotary NiTi instruments detected by periapical radiography and cone beam computed tomography.

This study detected procedural errors created by rotary nickel-titanium (NiTi) instruments during root canal preparation by two imaging methods. Forty extracted human maxillary and mandibular molars were divided randomly into two groups and treated by two endodontists (n=10) and two undergraduate dental students (n=10). The ProTaper Universal Rotary System was used to shape the canals and then they were filled using AH Plus sealer and gutta-percha. Periapical radiographs (PR) and cone beam computed tomography (CBCT) images were obtained and two examiners, who evaluated them to verify the occurrence of procedural errors (fractured instruments, perforations, and canal transportation). The Chi-square test at 0.05 level of significance was used for statistical analyses. There were no significant differences (p>0.05) between the imaging methods. In the analysis of procedural errors, there was no significant difference (p>0.05) between the groups of operators (endodontists vs. students) nor between tooth groups (maxillary molars vs. mandibular molars). In view of the low incidence of procedural errors during root canal preparation performed by students the introduction of rotary NiTi instruments has potential in undergraduate teaching. PR and CBCT permitted the detection of procedural errors, but the CBCT images offer more recourse for diagnosis.

Procedural errors during root canal preparation using rotary NiTi instruments detected by periapical radiography and cone beam computed tomography

This study detected procedural errors created by rotary nickel-titanium (NiTi) instruments during root canal preparation by two imaging methods. Forty extracted human maxillary and mandibular molars were divided randomly into two groups and treated by two endodontists (n=10) and two undergraduate dental students (n=10). The ProTaper UniversalTM Rotary System was used to shape the canals and then they were filled using AH PlusTM sealer and gutta-percha. Periapical radiographs (PR) and cone beam computed tomography (CBCT) images were obtained and two examiners, who evaluated them to verify the occurrence of procedural errors (fractured instruments, perforations, and canal transportation). The Chi-square test at 0.05 level of significance was used for statistical analyses. There were no significant differences (p>0.05) between the imaging methods. In the analysis of procedural errors, there was no significant difference (p>0.05) between the groups of operators (endodontists vs. students) nor between tooth groups (maxillary molars vs. mandibular molars). In view of the low incidence of procedural errors during root canal preparation performed by students the introduction of rotary NiTi instruments has potential in undergraduate teaching. PR and CBCT permitted the detection of procedural errors, but the CBCT images offer more recourse for diagnosis.

O objetivo deste estudo foi determinar erros de procedimentos ocorridos durante o preparo de canais radiculares após o uso de instrumentos de níquel-titânio (NiTi) acionados a motor, avaliados por dois métodos de exame por imagens. Quarenta molares humanos extraídos, superiores e inferiores, foram aleatoriamente divididos em dois grupos e tratados por dois especialistas em Endodontia (n=10) e dois estudantes de Odontologia (n=10). O sistema rotatório ProTaper UniversalTM foi usado para preparar os canais radiculares e, a seguir estes foram obturados com cimento AH PlusTM e guta percha. Radiografias periapicais (RP) e tomografia computadorizada de feixe cônico (TCFC) foram obtidas e avaliadas por dois examinadores para verificar a ocorrência de erros de procedimentos (instrumentos fraturados, perfurações e transporte apical). O teste do qui-quadrado com nível de significância de 0,05 foi usado para análise estatística. Frente a comparação dos métodos de exames por imagens não houve diferenças significantes (p>0,05). Na análise de erros de procedimentos (fraturas de instrumentos, perfurações e transportes apicais) não houve diferenças estatisticamente significantes nos níveis de operadores e nem entre grupos de dentes. Em vista da baixa incidência de erros de procedimentos durante o preparo de canais radiculares realizados por estudantes, a introdução de instrumentos de NiTi apresenta potencial no ensino da graduação. RP e TCFC permitiram detectar erros de procedimentos durante o preparo de canais radiculares, porém, a TCFC oferece maiores recursos para o diagnóstico.