NSK reciprocating handpiece: in vitro comparative analysis of dentinal removal during root canal preparation by different operators

Abstract

The purpose of this study was to assess dentin removal during root canal preparation by different operators using a NSK reciprocating handpiece. Eighty-four human single-rooted mandibular premolars were hand instrumented using Triple-Flex stainless-steel files (Kerr) up to #30, weighed in analytical balance and randomly assigned to 4 groups (n=21). All specimens were mechanically prepared at the working length with #35 to #45 Triple-Flex files (Kerr) coupled to a NSK (TEP-E10R, Nakanishi Inc.) reciprocating handpiece powered by an electric motor (Endo Plus; VK Driller). Groups 1 to 4 were prepared by a professor of Endodontics, an endodontist, a third-year dental student and a general dentist, respectively. Teeth were reweighed after root canal preparation. The difference between weights was calculated and the means of dentin removal in each group were analyzed statistically by ANOVA and Tukey's test at 5 % significance level. The greatest amount of dentin removal was found in group 4, followed by groups 2, 3 and 1. Group 4 differed statistically from the other groups regarding dentin removal means [p<0.001 (group 1); p=0.005 (group 2); and p=0.001 (group 3)]. No statistically significant difference was found between groups 1 and 2 (p=0.608), 1 and 3 (p=0.914) and 2 and 3 (p=0.938). In conclusion, although the group prepared by a general dentist differed statistically from the other groups in terms of amount of dentin removal, this difference was clinically irrelevant. The NSK reciprocating handpiece powered by an electric engine was proved an effective auxiliary tool in root canal preparation, regardless of the operator's skills.

Effect of finishing instrumentation using NiTi hand files on volume, surface area and uninstrumented surfaces in C‐shaped root canal systems

“…Instrumentation with the NSK reciprocating handpiece attached to an electric motor was chosen to standardize the movement kinematics because this is smoother than the motion provided by similar compressed air‐driven motors or even manual filing (Wagner et al . ). Furthermore, NiTi hand files were chosen for their smaller taper (0.02), increased flexibility and reduced dentine‐cutting ability compared to stainless steel hand files (Gambill et al .…”

“…The second result of this study is that finalizing instrumentation using NiTi hand files at a 90°-oscillatory contra-angle significantly decreases the remaining uninstrumented canal walls and the other studied parameters in C-shaped mandibular molars, rejecting our second hypothesis. Instrumentation with the NSK reciprocating handpiece attached to an electric motor was chosen to standardize the movement kinematics because this is smoother than the motion provided by similar compressed air-driven motors or even manual filing (Wagner et al 2006). Furthermore, NiTi hand files were chosen for their smaller taper (0.02), increased flexibility and reduced dentine-cutting ability compared to stainless steel hand files (Gambill et al 1996), promoting apical size enlargement with only a minor risk of overinstrumentation in the middle and cervical thirds.…”

Glide Path Enlargement of Mandibular Molar Canals by Using K-files, the ProGlider File, and G-Files: A Comparative Study of the Preparation Times

“…This technique is however associated with a higher risk of apical transportation with files larger than a 0.15 K-file (16); risk of excess dentine removal as a result of the clinician instrumenting the canal longer than necessary (21); risk of apical extrusion of debris if the handpiece is forced apically (20); and decreased tactile sensation.…”

Glide path preparation in Endodontics: case report and a literature review of available materials and techniques

“…28 The advantages of using a stainless steel K-File in a reciprocating hand piece for glide path enlargement include a reduction in preparation time; reduced operator and hand fatigue; and reduced risk of instrument separation compared with rotary NiTi methods. 29 The disadvantages include the need for a dedicated hand piece; the risk of apical transportation with files larger than a 15 K-File; 19 the risk of excess dentine removal as a result of the clinician instrumenting the canal for longer than necessary; 30 the risk of apical extrusion of debris if the hand piece is forced apically; 29 and decreased tactile sensation.…”