Ex vivo evaluation of the ability of the ROOT ZX II to locate the apical foramen and to control the apical extent of rotary canal instrumentation

An Ex-Vivo Study Comparing the Accuracy of the E-Connect S+ and Morita Tri Auto ZX2+ Endodontic Handpieces in Root Canal Length Determination

INTRODUCTION

This ex vivo study evaluated the accuracy of the Electronic Apex Locator (EAL) and Automatic Apical Stop (AAS) functions of the E-Connect S+ and Morita Tri Auto ZX2+ cordless apex locators in determining patency length.

METHODS

Sixty-four human teeth with a single root were randomly allocated into E-connect or Morita groups (n = 32). The canals were accessed and preflared, after which a size 15 K-file was inserted into the canal to the major foramen and recorded as the actual length (AL). Matched measurements were taken using the AAS and EAL functions and visually confirmed with confocal microscopy. The variance between canal length (mm), the persons correlation (ρ) between function and AL, and the accuracy (%) of the canal length relative to the AL (Δmm) between devices and functions were assessed.

RESULTS

Regardless of device or function, all measurements were within 1±Δmm and correlated strongly (ρ > 0.97) with the AL. When considering a more stringent clinically acceptable range of 0.5±Δmm from the AL, all devices and functions demonstrated similar accuracy levels (84%-94%). However, at lower tolerance ranges, the E-connect device with the EAL function exhibited the highest accuracy. On average, all devices and functions stopped short of the AL (mean Δmm>0).

CONCLUSION

The E-Connect S+ and Morita Tri Auto ZX2+ apex locators provided reliable accuracy in determining the position of the major foramen. These findings demonstrate a high level of reproducibility in canal length measurements using both cordless endodontic handpieces, regardless of whether the EAL or AAS functions were employed.

Influence of Embedding Medium on iPex Electronic Apex Locator Accuracy: An Ex Vivo Comparative Study Using Alginate, Saline, and Gelatin Models

AIM

Accurate working length determination during root canal treatment is essential for achieving successful outcomes. This study aimed to evaluate the impact of embedding medium on the accuracy of iPex electronic apex locator (EAL).

MATERIALS AND METHODS

Sixty-one extracted single-rooted teeth were decoronated and coronally flared with Gates-Glidden burs. Actual canal length (ACL) was obtained by introducing a size 8 K-file until its tip reached the most coronal border of the apical foramen. This step was performed thrice and then averaged. Deducting 0.5 mm from the ACL provided the working length (WL). The teeth were randomly placed in plastic containers filled with freshly mixed alginate, gelatin, or saline, with the lip clip placed in the medium. The blinded operator obtained electronic measurements using iPex by advancing a K-file with a size compatible with the canal attached to the file clip and advanced until the 0.0 mark, then withdrawn to the 0.5 mark. This step was performed thrice and then averaged. Data were analyzed using ANOVA and Tukey's post hoc test, with significance level set at 5% (α = 0.05).

RESULTS

The mean difference between WL and iPex length obtained in the gelatin model was significantly longer than the difference with mean iPex length in alginate (p = 0.005) and in saline (p < 0.001). There was no significant difference between iPex readings obtained in alginate and saline (p = 0.249).

CONCLUSION

The use of freshly mixed alginate or saline for ex vivo assessment of iPex is recommended, whereas the use of gelatin could increase the chances of readings longer than looked for.

CLINICAL SIGNIFICANCE

Identifying the optimum embedding medium for ex vivo testing of EALs permits the comparison and assessment of several factors affecting EALs' precision under standardized conditions. This helps in understanding EAL performance in vivo and in optimizing its clinical utilization.

Accuracy of electronic apical functions of a new integrated motor compared to the visual control of the working length-an ex vivo study

OBJECTIVES

To evaluate ex vivo the efficacy of the integrated motor Tri Auto ZX2 in controlling the apical extent of preparation compared to conventional visual control (CVC) of the working length (WL).

MATERIALS AND METHODS

Eighty standardized mandibular premolars were divided into five groups (n = 16). In the CVC group, instruments were used in continuous rotation (CR) and visual control performed by means of rubber stoppers. For each of the remaining groups, it was assigned a combination of a motion (CR or optimal torque reverse (OTR)), and an apical function (Auto Apical Reverse (AAR) or Optimum Apical Stop (OAS)). Root canals were prepared using the apical functions at 0.5 mark using an alginate model. Difference between the final WL and the actual length post-instrumentation was calculated. Data were analyzed statistically with the significance set at 5% (ANOVA, Tukey HSD).

RESULTS

There was no difference in the mean WL among the groups, except between the CR combined to OAS compared to CVC (P > 0.05). Although CVC resulted in two cases beyond the foramen, no significant difference was found among the groups when comparing the distributions of measurements (P > 0.05).

CONCLUSIONS

All combinations of motion and apical control functions of Tri Auto ZX2 provided an adequate apical limit ex vivo, similar to the visual control using rubber stoppers.

CLINICAL RELEVANCE

TriAuto ZX2 was efficient to control the apical extent of preparation dispensing the need for calibrating the files, regardless of the different settings. This motor might potentially prevent over-instrumentation by continuously monitoring the apical limit.

The accuracy of the auto-stop function of different endodontic devices in detecting the apical constriction

Background

Electronic apex locators (EALs) are modern devices used to determine the working length during root canal preparation. The newest endodontic motors provide an integrated EAL with auto-stop function to prevent instrumentation beyond the predefined working length during rotary root canal preparation. The aim of this study was to compare the accuracy of the auto-stop function of the VDW.Gold RECIPROC motor (VDW, Munich, Germany), the EndoPilot motor (Schlumbohm, Brokstedt, Germany) and the manual measurement with Raypex 6 (VDW, Munich, Germany) to detect the apical constriction (AC).

Methods

Ninety human teeth were chosen and randomly assigned to three experimental groups (30 teeth each): VDW.Gold RECIPROC motor continuous measuring (RCM), EndoPilot continuous measuring (ECM) and Raypex 6 manual measuring (RMM). When the measurement file reached the AC, the file was fixed in the tooth. The tooth was embedded in acrylic resin and the root tip was exposed, so that the histologic structure of the root canal and the file tip was visible for microscopic analysis. Afterwards, the distance of the file tip to the AC (D_AC) was automatically computed with a specially developed software tool.

Results

The mean D_AC were −13.18 μm (SD 88.46 μm) for RMM, −22.70 μm (SD 91.57 μm) for RCM and 18.74 μm (SD 88.11 μm) for ECM. The differences were not statistically significant (P = 0.181). The rates for instrumentation beyond the AC were not statistically different (Chi² = 4.753, p = 0.096).

Conclusions

All measurement methods showed a high accuracy in detecting the AC. The auto-stop function of these endodontic motors is a reliable addition to the endodontic armamentarium.

Efficacy of Electronic Foramen Locators in Controlling Root Canal Working Length during Rotary Instrumentation

Abstract: The present study evaluated the efficacy of electronic foramen locators (EFLs) to control root canal working length during rotary instrumentation and to assess possible reliability variations of different working lengths. Forty-eight human mandibular bicuspids were randomly divided in 2 groups according to the used device, Root ZX II (RZX) and Propex II (PRO). They were further subdivided in 2 subgroups according to the root canal preparation level (0.0 and -1.0). Preparation was performed with the Protaper rotary system using a crown-down technique. RZX was employed on its automatic auto-reverse mode (AAR) and PRO was used with the MPAS-10R contra-angle to monitor the preparation. The last used file (F3) was fixed, and the apical portion of the teeth was worn buccolingually, allowing to measure the extent between the file tip and the apical foramen (AF). The precision values of 0.0 mm and -1.0 mm were 100% and 0.0% for RZX, and 100% and 66.7% for PRO, respectively, with a range of ±0.5 mm. Statistical analysis showed no differences between the groups at 0.0 mm. However, at -1.0 mm, RZX showed the poorest results (0.96±0.11 mm), followed by PRO (0.43±0.23 mm). The difference between RZX and PRO was statistically significant. The EFLs were precise in maintaining the working length during rotary preparation when reaching the AF, but when their penetration was limited, both devices showed decreased precision; the RZX AAR failed in all instances.

Evaluation of Dentaport ZX and Raypex 6 electronic apex locators: an in vivo study

INTRODUCTION

Raypex 6 is an electronic apex locator (EAL) that has not yet been tested in vivo. The purpose of this in vivo study was to compare the accuracy of two EALs: the Dentaport ZX and the Raypex 6.

METHODS

The study involved 36 straight single-rooted teeth. A 10-K file was advanced until the EAL detected the major foramen. The file was fixed in a replaceable pattern of light-cured composite. The apical part of each canal was trimmed to expose the file tip. The distances from the file tips to the major foramen were measured.

RESULTS

Wilcoxon's signed Rank test found no significant differences between the Dentaport ZX and Raypex 6 in terms of their abilities to detect the major foramen (P = .52) The Dentaport ZX was accurate 82.35% of the time to ± 0.5 mm and 97.05% of the time to ± 1 mm, whereas the Raypex 6 was accurate 88.22% of the time to ± 0.5 mm and 100% of the time to ± 1 mm.

CONCLUSIONS

No statistically significant differences were observed between the performance of the Dentaport ZX and Raypex 6 EALs under the in vivo clinical conditions used in this study.