Revista de Odontologia da UNESP
https://revodontolunesp.com.br/article/doi/10.1590/1807-2577.07016
Revista de Odontologia da UNESP
Original Article

The dentin thickness remaining in the risk zone of mandibular molars after cervical preflaring with four methods

A espessura da dentina remanescente na zona de perigo após o pré-alargamento com quatro métodos

Sheila Leite PINTO; Marília Fagury Videira MARCELIANO-ALVES; Renata Ximenes LINS; Ermelindo Antônio RADETIC; Hélio Pereira LOPES

http://dx.doi.org/10.1590/1807-2577.07016 Rev. odontol. UNESP, vol.46, n1, p.1-6, 2017
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Abstract

Abstract: Introduction: Cervical preflaring is an important step of the canal system instrumentation, but can lead to excessive enlargement or root perforation.

Objective: Evaluate the remaining dentin thickness in the mandibular molars of mesial roots using cone beam computed tomography: Gates-Glidden (crown-down); Gates-Glidden (step-back); LA Axxess and Easy Pro-Design.

Material and method: Were selected 40 lower molars mesial roots, which were scanned in a cone beam CT scanner before and after preparation. Were obtained five sections of the CT images with an interval of 1 mm from the furcation, and measured the thickness variation between the root canal to the root external portion in analysis software.

Result: The evaluation of the different levels showed no significance within the same group for the Gates-Glidden group. On the other hand, were observed difference for LA Axxess (p=0.002) and Easy Pro-Design (p=0.005). In the intergroup analysis, were observed difference in all levels, especially for Gates-Glidden in the ascendant order (ANOVA and Tukey).

Conclusion: Within the limitations of these study, is possible to conclude that the protocol with greater wear in the cervical risk area was the Gates-Glidden in step-back sequence, as the other groups were equivalent (p>0.05).

Keywords

Dental instruments, root canal preparation, cone beam computed tomography

Resumo

Resumo: Introdução: O preparo cervical é uma etapa importante da instrumentação do sistema de canais, mas pode levar ao alargamento excessivo ou rasgo da raiz.

Objetivo: Avaliar, em tomografia computadorizada cone beam, da espessura remanescente de dentina cervical da raiz mesial de molares inferiores, após o preparo com diferentes técnicas: Gates-Glidden (ordem crescente); Gates-Glidden (ordem decrescente); LA Axxess e Easy Pro-Design.

Material e método: Foram selecionadas 40 raízes mesiais de molares inferiores, que foram escaneadas em tomógrafo cone beam antes e após o preparo. Das imagens tomográficas foram obtidos cinco cortes com intervalo de 1 mm a partir da furca e, então, mensurada a variação da espessura entre o canal radicular até a porção externa da raiz em software de análise.

Resultado: Avaliação dos diferentes níveis demonstraram ausência de significância dentro do mesmo grupo para o grupo das Gates-Glidden. Por outro lado, foi notada diferença para LA Axxess (p=0,002) e para Easy Pro-Design (p=0,005). Na avaliação entre os grupos, foi observada diferença em todos os níveis, sobretudo, para Gates-Glidden na ordem crescente (ANOVA e Tukey).

Conclusão: Considerando as limitações desse estudo, concluiu-se que o protocolo que apresentou maior desgaste da área de perigo cervical foi o da Gates-Glidden em ordem crescente, sendo que os demais grupos foram equivalentes (p>0,05).
 

Palavras-chave

Instrumentos odontológicos, preparo de canal radicular, tomografia computadorizada de feixe cônico

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