RESUMO
OBJECTIVE: This study evaluated the dynamic cyclic fatigue resistance of the XP-Endo Shaper (XPS), associated with chlorhexidine digluconate (CHX) or sodium hypochlorite (NaOCl) in two different formulations: gel (G) or liquid (L). MATERIALS AND METHODS: Sixty XPS were used in an artificial stainless-steel canal, and the files were fully immersed in the irrigating solution throughout the experiment until the fracture. The files were divided into six groups (n = 10) based on the irrigation solution used: NaOCl(L), NaOCl(G), CHX(L), CHX(G), natrosol gel (NAT) (control), and lubricating oil (LO) (control). The artificial canal was manufactured 1.5 mm wide, 20 mm long, and, 3.5 mm deep with a straight cervical segment measuring 14.29 mm; an apical segment of 4.71 mm with 3 mm radius; and 90 degrees of curvature apical 1 mm long straight segment. Resistance to cyclic fatigue was determined by recording the number of cycles to fracture (NCF). RESULTS: The CHX(G), CHX(L), and OIL (LO) groups showed no significant difference between them and presented longer time to fracture (p > 0.05). NaOCl(L) shows the lowest NCF without significant differences between NaOCl(G) and NAT. The NCF of the NaOCl(G) was statistically similar to the CHX(L) and statistically lower than the CHX(G) and OIL groups. NAT did not present a statistical difference of the NaOCl(L), NaOCl(G), and presented a significantly lower NCF than the CHX(G) (p < 0.01). CONCLUSION: The use of CHX(G) resulted in increased cyclic fatigue resistance of the XPS instruments compared to NaOCl or LO.
RESUMO
Objetivo: Avaliar, por meio de tomografia computadorizada de feixe cônico (TCFC), a morfologia dos canais radiculares de dentes incisivos inferiores, em uma população da região Sudeste brasileira, e sua relação com a idade e o sexo dos pacientes Métodos: Foram analisados 371 prontuários de pacientes de ambos os sexos que continham exames de TCFC, totalizando 1.484 dentes incisivos inferiores. As imagens tomográficas foram capturadas com o tomógrafo Orthopantomograph OP300, com voxel de 0,20mm. A morfologia dos dentes foi avaliada de acordo com a classificação de Vertucci, e foram investigados os efeitos do sexo e da idade dos pacientes sobre a variação na morfologia desses dentes. Resultados: Todos os dentes avaliados apresentaram apenas uma raiz; 80,7% dos incisivos inferiores apresentaram um único canal (Tipo I de Vertucci). O segundo canal esteve presente em 19,3% dos casos, sendo do Tipo II de Vertucci em 1,1%, Tipo III em 18,1%, Tipo IV em 0,1% e Tipo V em 0,1%. Não houve influência estatisticamente significativa (p=0,890) do sexo na morfologia dos incisivos inferiores. Dentro da faixa etária analisada, os indivíduos com menos de 18 anos e aqueles com 40 a 49 anos (28,2% e 26,8% respectivamente) apresentaram significância estatística (p=0,001) quanto à presença de segundo canal, compa- rados aos de outras faixas etárias. Conclusões: A morfologia mais prevalente foi a Tipo I de Vertucci, seguida pelo Tipo III, sem diferença entre os sexos, e com maior prevalência de variação morfológica nos indivíduos com menos de 18 anos e com 40 a 49 anos de idade (AU).
Objective: Evaluate the root canal morphology of per- manent mandibular incisors, through the use of cone bean computed tomography (CBCT) in a population of Brazilian southeast region and its relationship with patient age and sex. Methods: A total of 1,484 mandibular incisors of 371 male and female patient`s medical records were analyzed using CBCT. The tomographic images were by the orthopantomograph OP300 tomograph, with voxel of 0.20 mm. The morphology of the teeth was evaluated according to the classification of VERTUCCI, and the effects of sex and age of the patients on the variation in the morphology of these teeth were investigated. Results: All evaluated teeth had only one root. A single canal (Ver- tuccis type I) was detected in 80.7% of mandibular incisors. The second canal was present in 19.3% of the cases, with rates of 1.1% for Type II, 18.1% for Type III, 0.1% for Type IV, and 0.1% for Type V. According to sex, there was no statistical difference (p = 0.890) in mandibular incisor morphology. Within the analyzed age group, individuals aged under 18 years and individuals between 40 and 49 years (28.2% and 26,8% respectively) were statistically significant (p = 0.001) when compared to the other age groups. Conclusions: The most prevalent morphology was Type I of VERTUCCI, followed by Type III, without difference between sex and with a higher prevalence of morphological variation in individuals with less than 18 years and between 40 and 49 years (AU).
