Safety Assessment of Two Hybrid Instrumentation Techniques in a Dental Student Endodontic Clinic: A Retrospective Study

Abstract

The aim of this study was to retrospectively assess the safety potential of a hybrid technique combining nickel-titanium (NiTi) reciprocating and rotary instruments by third-and fourth-year dental students in the predoctoral endodontics clinic at one U.S. dental school. For the study, 3,194 root canal treatments performed by 317 dental students from 2012 through 2015 were evaluated for incidence of ledge creation and instrument separation. The hybrid reciprocating and rotary technique (RRT) consisted of a glide path creation with stainless steel hand files up to size 15/02, a crown down preparation with a NiTi reciprocating instrument, and an apical preparation with NiTi rotary instruments. The control was a traditional rotary and hand technique (RHT) that consisted of the same glide path procedure followed by a crown down preparation with NiTi rotary instruments and an apical preparation with NiTi hand instruments. The results showed that the RHT technique presented a rate of ledge creation of 1.4% per root and the RRT technique was 0.5% per root (p<0.05). Three stainless steel hand files separated: two in the RHT group and one in the RRT group. There was no separation of any NiTi file in any of the techniques. The use of the reciprocating and rotary technique for root canal instrumentation by these dental students provided good safety. This hybrid technique offered a low rate of ledge creation along with no NiTi instrument separation.

Locating the second mesiobuccal canal in maxillary molars: challenges and solutions

“…There is a small risk of separation of hand instruments that should be taken into account. 38 Recently, the use of reciprocating instruments was proven to properly clean these canals with minimal risk of incidents. 39 …”

Separation of Nickel-Titanium Rotary and Reciprocating Instruments: A Mini-Review of Clinical Studies

“…Shen et al , [ 30 , 31 ], have presented 0.3% for ProFile instrument files used up to 3 times, and 0.05% for ProFile Vortex files used by graduate students in a single use regimen. Coelho et al , [ 32 ], have presented no instrument separation in an undergraduate endodontic clinic. The NiTi rotary Vortex instruments were used in 3 root canal treatments if no sign of distortion was present [ 32 ].…”

“…Coelho et al , [ 32 ], have presented no instrument separation in an undergraduate endodontic clinic. The NiTi rotary Vortex instruments were used in 3 root canal treatments if no sign of distortion was present [ 32 ]. A recent clinical study has shown a separation rate of 0.83% for the Twisted File Adaptive after the use in 3 molars; no instrument separation occurred in the 2 first uses [ 33 ].…”

“…The separation rate of this prospective study was of 0.42% on a tooth level and 0.13% considering the number of canals [ 19 ]. Shen et al , [ 37 ], have presented 0.5% of 438 WaveOne instruments collected after clinical use; Coelho et al, have shown no separation of WaveOne instruments used in an undergraduate endodontic clinic [ 32 ]. The WaveOne system is manufactured with an M-Wire NiTi alloy which presents 390% more cyclic fatigue resistance then regular NiTi [ 38 ].…”

“…A following study showed 1 ProFile Vortex instrument separated in 2,203 instruments (0.05%); in both studies, the cases were completed by undergraduate students. A recent study also has shown no instrument separation for NiTi Rotary and reciprocating instruments [ 32 ]. The cases were performed by 3 rd and 4 th year undergraduate students.…”