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

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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

References

Schilder H. Cleaning and shaping the root canal. Dent Clin North Am. 1974 Apr;18(2):269-96. PMid:4522570.

Peters OA, Laib A, Göhring TN, Barbakow F. Changes in root canal geometry after preparation assessed by high-resolution computed tomography. J Endod. 2001 Jan;27(1):1-6. PMid:11487156. http://dx.doi.org/10.1097/00004770-200101000-00001.

Cunningham CJ, Senia ES. A three-dimensional study of canal curvatures in the mesial roots of mandibular molars. J Endod. 1992 Jun;18(6):294-300. PMid:1402588. http://dx.doi.org/10.1016/S0099-2399(06)80957-X.

Wu MK, van der Sluis LW, Wesselink PR. The risk of furcal perforation in mandibular molars using Gates-Glidden drills with anticurvature pressure. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2005 Mar;99(3):378-82. PMid:15716849. http://dx.doi.org/10.1016/j.tripleo.2004.07.008.

Stabholz A, Rotstein I, Torabinejad M. Effect of preflaring on tactile detection of the apical constriction. J Endod. 1995 Feb;21(2):92-4. PMid:7714445. http://dx.doi.org/10.1016/S0099-2399(06)81103-9.

Schroeder KP, Walton RE, Rivera EM. Straight line access and coronal flaring: effect on canal length. J Endod. 2002 Jun;28(6):474-6. PMid:12067134. http://dx.doi.org/10.1097/00004770-200206000-00015.

Davis RD, Marshall JG, Baumgartner JC. Effect of early coronal flaring on working length change in curved canals using rotary nickel-titanium versus stainless steel instruments. J Endod. 2002 Jun;28(6):438-42. PMid:12067124. http://dx.doi.org/10.1097/00004770-200206000-00005.

Barroso JM, Guerisoli DM, Capelli A, Saquy PC, Pecora JD. Influence of cervical preflaring on determination of apical file size in maxillary premolars: SEM analysis. Braz Dent J. 2005;16(1):30-4. PMid:16113930. http://dx.doi.org/10.1590/S0103-64402005000100005.

Zuckerman O, Katz A, Pilo R, Tamse A, Fuss Z. Residual dentin thickness in mesial roots of mandibular molars prepared with Lightspeed rotary instruments and Gates-Glidden reamers. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2003 Sep;96(3):351-5. PMid:12973293. http://dx.doi.org/10.1016/S1079-2104(02)91710-5.

Isom TL, Marshall JG, Baumgartner JC. Evaluation of root thickness in curved canals after flaring. J Endod. 1995 Jul;21(7):368-71. PMid:7499977. http://dx.doi.org/10.1016/S0099-2399(06)80972-6.

Johnson WT. Instrumentation of the fine curved canals found in the mesial roots of maxillary and mandibular molars. Quintessence Int. 1986 May;17(5):309-12. PMid:3460110.

Lemon RR. Nonsurgical repair of perforation defects: internal matrix concept. Dent Clin North Am. 1992 Apr;36(2):439-57. PMid:1349289.

Machado MLB, Antoniazzi JH, Machado MEL. Ação dos instrumentos rotatórios no preparo de canais radiculares: desgaste anticurvatura. Rev Assoc Paul Cir Dent. 2005 Maio-Jun;59(3):227-32.

Coutinho-Filho T, De Deus G, Gurgel-Filho ED, Rocha-Lima AC, Dias KR, Barbosa CA. Evaluation of the risk of a stripping perforation with Gates-Glidden drills: serial versus crown-down sequences. Braz Oral Res. 2008 Jan-Mar;22(1):18-24. PMid:18425240. http://dx.doi.org/10.1590/S1806-83242008000100004.

Sant’Anna Júnior A, Cavenago BC, Ordinola-Zapata R, De-Deus G, Bramante CM, Duarte MA. The effect of larger apical preparations in the danger zone of lower molars prepared using the Mtwo and Reciproc systems. J Endod. 2014 Nov;40(11):1855-9. PMid:25127935. http://dx.doi.org/10.1016/j.joen.2014.06.020.

Flores CB, Montagner F, Gomes BP, Dotto GN, da Silva Schmitz M. Comparative assessment of the effects of Gates-Glidden, Largo, LA-Axxess, and New Brazilian Drill CPdrill on coronal preflaring: cone-beam computed tomographic analysis. J Endod. 2014 Apr;40(4):571-4. PMid:24666914. http://dx.doi.org/10.1016/j.joen.2013.08.028.

Miranzi BAS, Miranzi AJS, Borges LH, Miranzi MAS, Menezes FCH, Mattar R, et al. In vitro evaluation of shape changes in curved artificial root canals prepared with two rotary systems. Dental Press Endod. 2011 Apr-Jun;1(1):69-76. http://dx.doi.org/10.14436/2178-3713.1.1.069-076.oar.

Goerig AC, Michelich RJ, Schultz HH. Instrumentation of root canals in molar using the step-down technique. J Endod. 1982 Dec;8(12):550-4. PMid:6962274. http://dx.doi.org/10.1016/S0099-2399(82)80015-0.

Coutinho-Filho T, Vianna GADC, Guimarães Pinto T, Gurgel-Filho ED, Maniglia-Ferreira C. A computer evaluation of the dentin remaining after cervical preparation in curved canals: gates-glidden drills vs. orifice shaper. Braz J Oral Sci. 2002 Out;1(3):116-20. http://dx.doi.org/10.20396/bjos.v1i3.8641105.

Weine FS, Kelly RF, Lio PJ. The effect of preparation procedures on original canal shape and on apical foramen shape. J Endod. 1975 Aug;1(8):255-62. PMid:10697472. http://dx.doi.org/10.1016/S0099-2399(75)80037-9.

Mizrahi SI, Tucker JW, Seltzer S. A scanning electron microscopic study of the efficacy of various endodontic instruments. J Endod. 1975 Oct;1(10):324-33. PMid:1061774. http://dx.doi.org/10.1016/S0099-2399(75)80012-4.

Mahran AH, AboEl-Fotouh MM. AboEl-Fotouh MM. Comparison of effects of ProTaper, HeroShaper, and Gates Glidden Burs on cervical dentin thickness and root canal volume by using multislice computed tomography. J Endod. 2008 Oct;34(10):1219-22. PMid:18793924. http://dx.doi.org/10.1016/j.joen.2008.06.022.

Alencar AHG, Dummer PMH, Oliveira HCM, Pécora JD, Estrela C. Procedural errors during root canal preparation using rotary NiTi instruments detected by periapical radiography and cone beam computed tomography. Braz Dent J. 2010;21(6):543-9. PMid:21271046. http://dx.doi.org/10.1590/S0103-64402010000600011.

Duarte MA, Bernardes RA, Ordinola-Zapata R, Vasconcelos BC, Bramante CM, Moraes IG. Effects of Gates-Glidden, LA Axxess and orifice shaper burs on the cervical dentin thickness and root canal area of mandibular molars. Braz Dent J. 2011;22(1):28-31. PMid:21519644.

Schmitz MS, Santos R, Capelli A, Jacobovitz M, Spanó JCE, Pécora JD. Influence of cervical preflaring on determination of apical file size in mandibular molars: SEM analysis. Braz Dent J. 2008;19(3):245-51. PMid:18949299. http://dx.doi.org/10.1590/S0103-64402008000300013.
 

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