Enhancing Endodontic Success

The success of endodontic treatment depends on cleaning and removing micro­or­gan­isms from the root canal sys­tem.^1,2 Chemical me­chanical pre­p­aration is one of the most important steps, as it aims to correctly model the root canal using metallic instruments, which must create sufficient space for the irrigating solution.⁴

The shaping must be performed safely and effectively without altering the original trajectory of the root canal. To achieve this, heat-treated NiTi mechanized instruments should be used due to their superior me­chanical behavior, flexibility, and re­sistance to cyclic fatigue compared to conventional NiTi instruments.^5,6 However, the type of heat treatment used is important as it directly affects the instruments’ flexibility.⁷

The controlled-memory (CM) heat treatment resists cyclic fatigue and flexibility, providing greater safety in treatment and enabling the enlargement of root canals, even those with pronounced curvatures without altering the original trajectory.^8,9 However, the increase in taper and diameter of these instruments results in more dentin removal, especially in the cervical region, which supports the transfer of occlusal forces through the root, influencing the longevity of the tooth and its ideal function.^10,11

As such, NiTi mechanized instruments with reduced taper in the cervical portion have been developed, aiming to preserve dentin in this region.¹² Among them is the Logic system made by BassiEndo, Belo Horizonte, Minas Gerais, Brazil, which offers CM heat treatment and a maximum cervical diameter of #100, independent of the tip diameter and tapper, allowing the apical third to be enlarged without remove cervical dentin. The greater apical enlargement of the root canal facilitates the cleaning and removal of infected dentin, reduces the uninstrumented surface of root canals, and enhances the performance of the irrigating solution.^6,13,14

The assessment of how much the root canal should be enlarged at the apex should be based on individual considerations, considering the substantial anatomical variations found in teeth.¹⁵ BassiEndo’s Logic system offers instruments with different tapers for the same diameters, allowing the instrument size to be selected based on dental anatomy and the stage of endodontic treatment: glide path, shaping, and accessory shaping (Figure 1). To identify both, a system of colored rings appears on the mandrel, indicating the diameter and taper (Figure 2).

The instruments’ cross-sectional design was conceived according to their diameter and function. The 0.1 taper instruments and joker instruments have a square cross-section, which provides greater instrument rigidity due to their higher metal mass. This is essential for instruments with a small diameter and taper, as it allows them to advance in the root canal. The other root canal-shaping instruments have an S-shaped cross-section, enabling greater cutting capacity even with high flexibility (Figure 3).

The variable interlaminar distance of these instruments increases cutting capacity and prevents the screwing effect in the root canal, which, combined with the inactive tip, increases the safety of their use.

Knowledge about the different NiTi metallic instruments on the market allows for better planning and expands the possibility of resolving different cases.

References

1. Sjogren U, Hagglund B, Sundqvist G, Wing K. Factors affecting the long-term results of endodontic treatment. J Endod. 1990;16:498–504.
2. Ng YL, Mann V, Rahbaran S, Lewsey J, Gulabivala K. Outcome of primary root canal treatment: systematic review of the literature — part 1. Effects of study characteristics on probability of success. Int Endod J. 2007;40:921-39.
3. Carvalho MC, Zuolo ML, Arruda-Vasconcelos R, et al. Effectiveness of XP-Endo Finisher in the reduction of bacterial load in oval-shaped root canals. Braz Oral Res. 2019;33:e021.
4. Haapasalo M, Shen Y, Qian W, Gao Y. Irrigation in endodontics. Dent Clin North Am. 2010;54:291–312.
5. Frota MMA, Bernardes RA, Vivan RR, Vivacqua-Gomes N, Duarte MAH, Vasconcelos BC. Debris extrusion and foraminal deformation produced by reciprocating instruments made of thermally treated NiTi wires. J Appl Oral Sci. 2018;26:e20170215.
6. Pinheiro SR, Alcalde MP, Vivacqua-Gomes N, et al. Evaluation of apical transportation and centring ability of five thermally treated NiTi rotary systems. Int Endod J. 2018;51:705–713.
7. Zupanc J, Vahdat-Pajouh N, Schäfer E. New thermomechanically treated NiTi alloys — a review. Int Endod J. 2018;51:1088–1103.
8. AlShwaimi E. Cyclic fatigue resistance of a novel rotary file manufactured using controlled memory Ni-Ti technology compared to a file made from M-wire file. Int Endod J. 2018;51:112–117.
9. Shen Y, Qian W, Abtin H, Gao Y, Haapasalo M. Fatigue testing of controlled memory wire nickel-titanium rotary instruments. J Endod. 2011;37:997-1001.
10. Clark D, Khademi J. Modern molar endodontic access and directed dentin conservation. Dent Clin North Am. 2010;54:249–273.
11. Pierrisnard L, Bohin F, Renault P, Barquins M. Corono-radicular reconstruction of pulpless teeth: a mechanical study using finite element analysis. J Prosthet Dent. 2002;88:442–448.
12. Torabinejad M, Khademi AA, Babagoli J, et al. A new solution for the removal of the smear layer. J Endod. 2003;29:170–175.
13. De-Deus G, Belladonna FG, Silva EJ, et al. Micro-CT evaluation of non-instrumented canal areas with different enlargements performed by NiTi systems. Braz Dent J. 2015;26:624–629.
14. Srikanth P, Krishna AG, Srinivas S, Reddy ES, Battu S, Aravelli S. Minimal apical enlargement for penetration of irrigants to the apical third of root canal system: a scanning electron microscope study. J Int Oral Health. 2015;7:92–96.
15. De-Deus G, Belladonna FG, Silva EJ, et al. Micro-CT evaluation of non-instrumented canal areas with different enlargements performed by NiTi systems. Braz Dent J. 2015;26:624–629.

BassiEndo
BassiEndo.com
800-234-0045

From Decisions in Dentistry.November/December 2023; 9(10):20