Comparative Evaluation of Efficacy of Protaper Universal Retreatment System, R-Endo System and Hedstrom File in Gutta Percha Removal During Root Canal Retreatment- An In Vitro Study.

Background: The complete removal of residual filling materials from the root canal determines the success of root canal retreatment. Aim: To evaluate and correlate the efficacy of ProTaper retreatment system, R-Endo retreatment system, and Hedstrom file in the removal of gutta-percha and sealer from root canal during endodontic retreatment in addition to the period desired for the elimination of gutta-percha and sealer. Methodology: Thirty extracted premolars were prepared and filled by cold lateral compaction with gutta-percha and sealer. Retreatment was finished with ProTaper retreatment files, R-Endo files, Hedstrom files with Endosolv E as the solvent for 10 specimens each. Each half of the root was imaged using the image analyzer software Chroma allied to a stereomicroscope with 10× magnification via a charge-coupled device sensor. For statistical analysis, parametric one-way ANOVA test and Scheffe post hoc multiple range test were utilized at a significance level of P < 0.05.
Results: There is no significant difference among the three groups at P < 0.0001 in removing filling material. However, the rotary files needed significantly less time for removing gutta-percha along with sealer than H-file (P < 0.0001).
Conclusion: The gutta-percha and sealer were found in the root canal subsequent to all the retreatment techniques, especially in the apical third. Retreatment time was less only for the rotary system. Copyright:

INTRODUCTION

Exclusion of gutta-percha along with sealer at the root line can be done by hot, mechanical, chemical, or a technique with a combination of the three.[1234567] Recently, NiTi root canal tools were introduced through retrieval processes. The elimination of the filling material in the trench can be done efficiently by combining rotating retrofit files with gutta-percha solvent[89] ProTaper retreatment (Dentsply Maillefer, Ballaigues, Switzerland) system includes three flexible tools (D1, D2, and D3) specially designed for the removal of gutta-percha root canal. R-Endo retreatment system (Micro-Mega, Besancon, France) consists of four tools: Re (file size: 25, 0.12 taper) to explode a few millimeters of first coronal, R1 (file size: 25, 0.08 taper) provided in the coronal third to size, R2 (file size: 25, 0.06 taper) rendered in the third medium, and R3 (file size: 25, 0.04 taper) provided in the third apical. Additional Rs complete file (file size: 30, 0.04 taper) is obtainable. These files have a rectangular cross-section with three cut edges that are evenly spaced and no flat earth; the tip of the file is not cut.[891011] The combination of different restoration techniques can be very effective and save time in removing filler materials in the trench. It is important to evaluate the effectiveness of these new systems and techniques so that they can be used clinically as efficiently as possible. The aim of this study was to assess the efficacy of ProTaper Universal rotary retreatment system, R-Endo system and Hedstrom file with Endosolv E as solvent for the removal of filling material from root canal during retreatment and to correlate the time required for the removal.

METHODOLOGY

In this study, 30 mandibular premolar teeth with Vertuccis I suspension were selected. Access arrangements were made using round burs No. 2 on a hand clip with high speed under the air spray to enter a straight line into the trenches. The cusps were flattened using a carborundum disk (Dentorium, New York, USA) centered on a high-speed handcuff (Marathon, Korea), for a typical working length of 15 mm. The bio-machine modification of the canal was done in the form of a 35-apical file size by using K-type files (Dentsply, Maillefer, Switzerland). Gates Glidden drills 1, 2, and 3 (Dentsply, Maillefer, Switzerland) were used to repair a third of the cervical canal. In between each instrument canals were irrigated with 3 ml of 5.2% sodium hypochlorite (Septodont health care India Pvt. Ltd), and final rinse was done with 0.9% normal saline (Septodont health care India Pvt. Ltd) and 17% EDTA (Dent Wash, Prime Dental Products, Pvt. Ltd). The selected Master cone gutta-percha of the standard size ISO 35 (Dentsply Maillefer, Ballaigues, Switzerland) was fitted with a pullback during operation. Radiograph was taken from the gutta-percha apical examination. The roots were dried using paper points. The ZOE (Tubliseal EWT, Kerr, Italy) sign was then applied to the root walls by using a master cone gutta-percha. Obturation was completed by means of a side joint by using a finger spreader (Dentsply Maillefer, Ballaigues, Switzerland). Heated hand plugger was used to cut the gutta-percha till the orifice. The access cavities were temporized with a minimum of 2 mm Cavit (ESPE). Obturation was examined radiographically. The specimens were stored in an incubator at 100% humidity and 37°C for 7 days. Invisible teeth were randomly alienated into three groups of ten, namely group I: ProTaper retreatment files, Group II: R-Endo files, and group III: H files used to obtain gutta-percha. All specimens were divided into lengths by using a carborundum disc. Each half of the root was imaged using charged coupled device sensor camera attached to a stereomicroscope with 10X magnification and images analysed using software Chroma [Figure 1]. The ratio of the remaining filling items was calculated using the following equation:

Figure 1

Graphic representation of the comparison of remaining filling material in apical, middle, and coronal third among three groups

The time needed for the instrument to accomplish the working length and for the elimination of filling material from starting until completion of re-instrumentation was documented to the nearest second by using a stopwatch. The results so obtained were recorded, compiled, and put to statistical analysis [Figure 2]. For statistical analysis, SPSS 10 for Windows (SPSS Inc, Chicago, IL) was utilized. Parametric one-way ANOVA test was used. Ethics committee is obtained by 7/12/2017.

Figure 2

Graphical representation of time taken for retreatment

RESULTS

The findings revealed that not one of the retreatment systems can entirely eradicate the infill materials from the canal. There was no statistically significant difference between the groups (P = 0.0001). The time it took to eradicate the infill materials from within the canal was compared using a one-way ANOVA test and a Scheffe post hoc test. There was a substantial difference between groups, as evidenced by the P = 0.0001 value. The ProTaper retreatment system and R-Endo system took much less time to remove gutta-percha and sealer than the hand instrument (P = 0.0001). Between the groups that retreated using the ProTaper retreatment system and those that retreated with the R-Endo system, there was no significant variance in the meantime recorded during retreatment (P = 0.980).

DISCUSSION

In this current study, dental implants were made to determine the working length to 15 mm. Al-Omari MAO and Dummer PMH.[121314] reported that the decoration allows for improved conception of the root canal and removes coronal distortions all through tunnel adjustment and retraction. Masiero AV and Barletta FB,[15] however, argued that the decoration helps to set the pattern as it removes other variables, such as crown anatomy and admittance to a straight line in the canals that allows for more accurate comparisons between reversal techniques. During instrumentation, conc. sodium hypochlorite (NaOCl) 5.2% was utilized as a root canal irrigant. Sodium hypochlorite is an effective antimicrobial agent capable of eliminating root toxins. Harrison and Hand[1617] showed that the acquisition of necrotic tissue reduced the antibacterial properties of 5.25% NaOCl. In the present-day trial, Endosolv E is utilized as a solvent as it is effective in removing root filling with zinc oxide eugenol-based sealer that contains tetrachlorethylene. Faria Junior et al.[17] tested three solvents for efficacy (eucalyptol, tetrachlorethylene, and citrus oil) and found tetrachlorethylene to be very effective in normal gutta-percha. Chloroform is considered to be a class-2B carcinogenic material, acknowledged to be the utmost effective solvent for gutta-percha.[1819] Saad et al.[20] reported that routine eradication of gutta-percha used or excluding solvent hand files may be time-consuming and dreary. Consequently, the usage of Rotary NiTi tools in restoring root canal might reduce patient and operator exhaustion. From the results obtained, it is evident that the amount of remaining filling material in all the three groups was maximum in apical region and minimum in cervical regions of root canals. These findings agree with the results reported by Ferreira et al.[21] and Gergi and Sabbagh,[22] who compared hand-held and rotating instruments and reported the remaining canal filling in the apical third section rather than in the third-coronal third. of the strategy used. The median retrieval period was longer in group III (Hedstrom files) and shorter in group I (ProTaper recovery program). The average values of this study during retrospect are similar to those reported in trials by Sae-Lim V et al.[23] and Hulsmann and Bluhm,[12] which showed that motor-driven tools work much faster than hand-operated metal drives. Although rotating tools eradicate the gutta-percha and lid from root canals to a greater extent compared to Hedstrom files, no research techniques have resulted in complete gutta-percha removal and shutter in root canals. However, there was no significant difference amid the rotating metal bands.

CONCLUSION

Within the limit of this in-vitro study, we conclude that no strategy can completely remove gutta-percha and sealant. The amount of guttapecha and sealer is more in apical one third than coronal third and middle third. The retrieval time is more for hand-filling with Hedstrom files compared to that for an automated retrieval system such as the ProTaper universal retreatment system and the R-Endo system. It is recommended that additional steps should be incorporated to completely confiscate the filling material.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.