Comparative study of ProTaper gold, reciproc, and ProTaper universal for root canal preparation in severely curved root canals

Precision-milled simulated curved root canals in bovine dentine for the assessment of chemo-mechanical root canal preparation

AIM

The aim was to develop a standardized curved root canal model in bovine dentine and to assess whether that natural substrate would behave differently from the resin in standard plastic training blocks when prepared chemo-mechanically. The impact of substrate microhardness on simulated canal transportation was considered.

METHODOLOGY

High-precision computer numerical control (CNC) milling was used to recreate a simulated root canal from a resin training block (Endo Training Bloc J-Shape, size 15) in longitudinally sectioned, dis- and re-assembled bovine incisor roots. Optical overlays obtained from 10 resin blocks were used to identify an average canal and program the CNC milling apparatus accordingly. Resin and dentine microhardness were measured. Simulated root canals in resin training blocks and their bovine counterparts were then instrumented at 37°C using Reciproc R25 instruments (VDW) with water or 17% EDTA (n = 10). Open-access image processing software was used to superimpose and analyse pre- and postoperative images obtained with a digital microscope. Centering ratios were averaged to indicate canal transportation. The effects of substrate and irrigant on canal transportation were assessed by two-way anova.

RESULTS

Superimposed images showed that resin blocks under investigation varied considerably in terms of simulated canal length and curvature, whilst the milled canals were highly similar. The microhardness of dentine was more than three times higher than that of the resin. Conversely, canal transportation was considerably greater in dentine compared to resin, and in dentine had a tendency to be increased by EDTA. There was a strong effect of substrate on canal transportation (p < .001), no overall effect of irrigant, and a marginally significant interaction between irrigant and substrate (p = .077).

CONCLUSIONS

CNC milling allows to create standardized simulated curved root canals in bovine dentine. These models may be useful to test and compare materials and concepts of chemo-mechanical root canal instrumentation. Microhardness is a bulk feature that does not predict the response to chemo-mechanical instrumentation of a composite material such as dentine.

Shaping ability of ProTaper Gold and WaveOne Gold nickel-titanium rotary instruments in simulated S-shaped root canals

Background/purpose

Gold metal technology improves flexibility and the resistance to cyclic fatigue of the endodontic mechanical files. This study compared the performance of ProTaper Gold (PTG) multiple file system and WaveOne Gold (WOG) single file system in simulated S-shaped root canals, which represents one of the most challenging root canal morphology.

Materials and methods

Forty S-shaped canals (n = 20 canals/per group) in resin blocks were instrumented to an apical size of 0.25 mm using PTG and WOG Primary, respectively. The total amount of resin removal, canal transportation, centering ratio, and the degree of canal straightening were measured in Photoshop CS6 software. Statistical analysis was performed by using Mann–Whitney U-test (α = .05).

Results

None of the files fractured during the instrumentation. The WOG group removed significantly less amount of resin at 0, 3, 6, 7 and 9 mm from the apex (P < .05). The WOG group remained more centered in canals at 0 mm from the apex (P < .05). The PTG group showed a better centering ability and less canal transportation at 4, 5 and 6 mm from the apex (P < .05). In the coronal curvature portion, the use of WOG Primary significantly decreased curvature angle and increased radius compared with PTG instruments (P < .05). There was no significant difference between the two groups in terms of the apical curvature angle and radius change (P > .05).

Conclusion

The WOG Primary file has a less aggressive dentin cutting and more centered apical preparation. The PTG system is more advantageous in shaping the coronal curvature of S-shaped canal.

The Effect of Speed and Rotation for Protaper File Systems on Postobturation Pain in a Single Visit and Multiple (Two) Visits in Root Canal Therapy: An In Vivo Study

INTRODUCTION

The basic idea of a root canal treatment is to alleviate the pain and heal the infection within the infected tooth, which can be resolved in a single visit or multiple visits in root canal therapy. Therefore, in this article, an in vivo comparison of single visits and multiple visits using different rotation and speed for two Protaper universal design file systems is done on the basis of time taken and incidence of pain.

MATERIALS AND METHODS

One hundred single-rooted premolars with irreversible symptomatic pulpitis were assigned to two groups of 50 patients each using the odd-even method, GA to be treated endodontically in a single visit and GB to be treated endodontically in multiple visits. Each group was further divided into two subgroups of 25 patients each on the basis of two different variations of speed and rotation for two Protaper file systems of the same design, GA1 (Hand Protapers) and GA2 (Rotary Protapers), GB1 (Hand Protapers) and GB2 (Rotary Protapers), respectively. After proper biomechanical shaping and cleaning, obturation was done with Gutta-percha cones and Ah plus sealer using Fast Pack obturation pen for warm vertical compaction. The pain was measured by a 100 mm modified visual analogue scale, and time was measured using a stopwatch.

RESULTS

At 6-h intervals, post-obturation pain was more in single-visit root canal therapy than multiple-visit root canal therapy (P < 0.01). Single-visit rotary Protaper (GA2) had less incidence of post-obturation pain as compared with single-visit hand protapers (GA1) (P < 0.05). There was no significant difference in post-obturation pain in the multiple-visit hand protaper subgroup (GB1) and multiple-visit rotary protaper subgroup (GB2) (P > 0.05). Preoperative pain significantly influences the post-obturation pain. The statistical analysis was done using SPSS (Statistical Package for Social Sciences) version 17.0 statistical Analysis Software.

CONCLUSIONS

The presence of preoperative pain can significantly influence the presence of postoperative pain. Most of the pain in both single-visit and multiple-visits root canal therapy occurred in the first 48 h after obturation, which decreases thereafter. Single-visit rotary protaper (GA2) had less incidence of post-obturation pain as compared with single-visit hand protapers (GA1). There was no significant difference in post-obturation pain in the multiple-visit hand protaper subgroup (GB1) and multiple-visit rotary protaper subgroup (GB2). Presence of sealer puff influences the duration of pain.

Comparative evaluation of canal transportation, centering ability, and dentin removal between ProTaper Gold, One Curve, and Profit S3: An in vitro study

Aim:

The aim of the study was to compare the canal transportation, centering ability, and dentin removal of Profit S3 (PS3), One Curve (OC), and ProTaper Gold (PTG) systems using cone-beam computed tomography (CBCT).

Materials and Methods:

Thirty extracted human single-rooted premolars were used in the present study. Preinstrumentation scanning of all the teeth in arch form was taken using CBCT. To increase standardization, crowns were removed and only teeth measuring 16 mm were included in the study. The samples were randomly divided into three groups, with ten samples in each group; Group I was instrumented with PS3, Group II was instrumented with OC, and Group III – PTG. Postinstrumentation scans were performed, and the two scans were compared to determine canal transportation, centering ability, and dentin removal at 3, 6, and 9 mm, from the apex.

Statistical Analysis:

One-way-ANOVA and the independent t-test were done for the pairwise comparison. The significance level was set at P = 0.05; statistical analysis was performed with SPSS statistics version 20.0 (SPSS Inc., Chicago, IL, USA).

Results:

The mean canal centering ratio and canal apical transportation for PS3, OC and PTG show no statistical difference (P > 0.05). The mean value of dentin removal showed a statistically significant difference between the three groups (P < 0.05). PS3 and OC rotary file showed less removal of dentin compared to PTG (P < 0.00).

Conclusion:

It was evident that PS3, OC, and PTG had no statistically significant difference when analyzed based on canal transportation and canal centering ratio. However, there was a significant difference among the three groups comparing the removal of dentin. PS3 and OC rotary file showed less removal of dentin compared to PTG.