Comparison of Cleaning Efficacy of Different Rotary Files in Primary Teeth-An In vitro Study

Aim

The aim of the present study was to comparatively assess the cleansing efficiency of dissimilar rotary files in deciduous teeth.

Materials and Methods

Forty-five deciduous anterior teeth that had been subjected to extraction were chosen for this research. The teeth were included if they had a minimum of 2/3rd undamaged root portions. Coronal entrée was completed using round diamond burs. All 45 samples were allocated at random to one of the following three groups: Group I: Control group in which the radicular canal was not subjected to any form of instrumentation, Group II: The radicular canal was subjected to instrumentation employing rotary ProTaper files, Group III: The radicular canal was subjected to instrumentation with rotary MTwo files. The samples were subjected to immersion in a succession of diluted ethyl alcohols to permit dehydration: With a change of solution every eight hours, the first 16 hours were spent in 70% alcohol, followed by eight hours in 80% alcohol, eight hours in 95% alcohol, and eight hours in 100% alcohol. The samples thus subjected to dehydration were cleared by immersion in methyl salicylate for six hours. Under a stereomicroscope with a 10x magnification, the root canals were examined by a person who was blinded to the groups in order to look for any traces of ink in the coronal, middle, and apical third of the canals.

Results

In the control group, greater residual remains were present in the apical 3rd at 2.16 ± 0.08 followed by the coronal 3rd at 2.02 ± 0.14, and then in the middle 3rd at 1.88 ± 0.10. While using the ProTaper files, greater residual remains were present in the middle portion at 1.68 ± 0.16, followed by the coronal third at 0.94 ± 0.09, then the apical third at 0.98 ± 0.22. Greater residual remains were again noted with the MTwo files in the mid-portion at 1.44 ± 0.18, followed by the coronal part at 0.86 ± 0.10 and then the apical part at 0.82 ± 0.04. Differences among these groups were statistically significant with a P value < 0.001.

Conclusion

The present study concluded that either of the file types used exhibited reasonably lower remnant score values in the apical third versus the middle/coronal thirds. Nonetheless, MTwo type files delineated superior capacity at removing debris versus the ProTaper file types at the apical level.

Exploring a Paradigm Shift in Primary Teeth Root Canal Preparation: An Ex Vivo Micro-CT Study

Traditional hand instrumentation is a commonly used technique to perform pulpectomy in deciduous teeth by most specialists in pedodontics. Lately, dentists have embraced rotary instrumentation as a safe and effective alternative. This study aimed to compare the efficacy of root canal preparation in extracted primary molars between manual and two rotary file systems using micro-CT. Thirty-six extracted human second primary mandibular molars were divided into three groups according to the instrumentation method: (1) Manually instrumented (MI) group (n = 9) in which the teeth were treated using K-files up to size 30; (2) Kedo-Ssystem (KS) group (n = 9); (3) ProTaper Gold system (PTG) group (n = 10) and control group (n-8). Each tooth was scanned before and after the retrograde root canal preparation. Residual dentin volume was calculated using micro-CT scans to evaluate the technique's efficacy. Additionally, the preparation time and procedural errors were recorded for each tooth preparation. A one-way ANOVA test was carried out to compare the groups' dentin volume and preparation time. The mean preparation time using the manual method (13.14 min) was more than two times longer than that of the rotary techniques (4.62 min and 6.45 min). The manual preparation method using a K-file removed almost half the root canal material when compared with the rotor method (p = 0.025). Conclusion: our results suggest that rotary instrumentation is more efficient for root canal preparation in primary teeth than the traditional manual method. This finding may call for a paradigm shift in current clinical practices, where manual instrumentation is still commonly preferred.

The effect of rotary instrumentation on dentin thickness in the danger zone of the MB2 canal of maxillary first molars

The aim of this study was to measure the initial and remaining dentin thickness in the danger zone of the second mesiobuccal (MB2) canal of maxillary first molars after rotary instrumentation using cone beam computed tomography (CBCT) imaging. After determining initial dentin thickness, each sample was subjected to a standardized protocol of rotary instrumentation files: ProTaper Gold Sx Orifice Opener (maximum depth of 7 mm); Vortex Blue 15.04, 20.04, 25.04, ProTaper Gold S1, S2, F1, F2, and finally Vortex Blue 30.06. Subsequent CBCT measurements were made to compare changes in remaining dentin thickness in comparison to initial presentation. Preoperative dentin thickness in the danger zone had a mean of 0.82 ± 0.17mm. Significant levels of dentin removal in the danger zone were noted after all instrumentation groups when compared to the pre-instrumentation mean (Sx P < 0.001, 25.04 P < 0.0006, F2 P < 0.0001, 30.06 P < 0.0001). It was concluded that a thin area of dentin exists along the distal wall of the MB2 (danger zone) from the furcation to 4 mm apically.

Shaping efficiency of XP-endo shaper and Mtwo instruments in long oval root canals: A micro-CT study

This study evaluated the shaping ability of XP-endo Shaper and Mtwo systems in long-oval-shaped canals of extracted human mandibular molars using micro-computed tomography (micro-CT). Images recorded before and after preparation were evaluated for morphometric measures regarding increase in canal volume, dentin removed, surface area, untouched walls and structure model index (SMI). Data were statistically analysed using the Mann-Whitney test with 5% of significance. On both groups, the root canal preparation significantly increased all analysed parameters (P > 0.05). There was no statistical difference between XP-endo Shaper and Mtwo systems in the increase of the canal volume (30.50%-27.82%), in volume of dentin removed (2.77%-2.40%), in the increase of the canal surface area (11.30%-8.86%), in canal untouched surfaces (9.57%-8.51%) and in the SMI (2.59%-2.68%), respectively. XP-endo Shaper and Mtwo systems showed similar shaping efficiency and were not able to completely prepare the walls of long-oval-shaped canals of extracted human mandibular molars.

Comparison of quality of obturation and instrumentation time using hand files and two rotary file systems in primary molars: A single-blinded randomized controlled trial

Objective:

In permanent dentition, different rotary systems are used for canal cleaning and shaping. Rotary instrumentation in pediatric dentistry is an emerging concept. A very few studies have compared the efficiency of rotary instrumentation for canal preparation in primary teeth. Hence, this study was performed to compare the obturation quality and instrumentation time of two rotary files systems – Protaper, Mtwo with hand files in primary molars.

Materials and Methods:

Forty-five primary mandibular molars were randomly allotted to one of the three groups. Instrumentation was done using K-files in Group 1; Protaper in Group 2; and Mtwo in Group 3. Instrumentation time was recorded. The canal filling quality was assessed as underfill, optimal fill, and overfill. Statistical analysis was done using Chi-square, ANOVA, and post hoc Tukey test.

Results:

No significant difference was observed in the quality of obturation among three groups. Intergroup comparison of the instrumentation time showed a statistically significant difference between the three groups.

Conclusion:

The use of rotary instrumentation in primary teeth results in marked reduction in the instrumentation time and improves the quality of obturation.

Comparative assessment of dentin removal following hand and rotary instrumentation in primary molars using cone-beam computed tomography

OBJECTIVE

Pediatric endodontics has witnessed many advances in recent years, thus facilitating a faster and efficient treatment option in root canal therapy in children. This in vitro evaluation aims to determine the amount of dentin removal in primary mandibular first and second molars instrumented with hand and rotary files using cone-beam computed tomography (CBCT).

MATERIALS AND METHOD

Sixty primary mandibular molars were divided into two groups: Group I was prepared by manual instrumentation using K-type files and Group II was prepared with rotary instrumentation using 0.04 Hero Shaper Classics. Both these groups were further divided into two subgroups, namely (a) primary mandibular first molar and (b) primary mandibular second molar. All the root canals were prepared up to size 30 using the stepback technique. They were mounted on silicone-based impression material and subjected to CBCT scans for the evaluation of dentin removal before and after instrumentation. Dentin removal was calculated by superimposing images using the InVivo 5.1 Anatomage software. Data were statistically analyzed using independent samples t- test.

RESULTS

An average amount of dentin removed was found to be significantly higher in manual instrumentation compared to rotary instrumentation in both primary mandibular first and second molars (P < 0.001).

CONCLUSIONS

Rotary technique serves as an efficient alternative to the traditional manual instrumentation by overcoming its shortcomings in terms of conservation of the remaining dentin thickness and the time required for its preparation.

Comparative evaluation of three different rotary instrumentation systems for removal of gutta-percha from root canal during endodontic retreatment: An in vitro study

Context:

Endodontic retreatment is performed in teeth with endodontic failures. The main goal of retreatment is cleaning and shaping of the root canal with removal of old root filling material. Hand instruments and rotary instruments are mainly used for removing this filling material.

Aim of Study:

To compare the relative efficacy of three rotary instrumentation systems for removal of gutta-percha from root canal during endodontic retreatment.

Objective of Study:

To find out which NiTi system is more efficacious in retreatment and to check out the efficacy of retreatment with and without use of solvent.

Materials and Methods:

Sixty freshly extracted, single-rooted human mandibular premolars were instrumented with K-files, and each root canal was filled with gutta-percha and AH Plus (Dentsply Detrey, Konstanz, Germany) sealer using lateral compaction. Specimens were then divided into three experimental groups with twenty specimens each. Groups were then subdivided into ten specimens each. Groups were then retreated either with or without solvent. The removal of gutta-percha was performed using ProTaper retreatment files, Mtwo retreatment files, and R-Endo files after 2 weeks. The amount of root canal filling material remnant in the coronal, middle, and apical thirds was measured using stereomicroscope and computer image analysis program.

Statistical Analysis Used:

Data were evaluated statistically using analysis of variance.

Results:

ProTaper group was found to have less remnant filling material as compared to the other groups in coronal and middle thirds, but a significant difference was observed between ProTaper and Mtwo and Mtwo and R-Endo in the nonsolvent groups (P < 0.05). Mtwo group demonstrated less amount of remaining filling material in the nonsolvent group.

Conclusions:

Both nickel–titanium systems and ProTaper and Mtwo retreatment file systems, were found to be effective in the removal of root canal filling material. However, complete removal of gutta-percha from root canals did not occur with any of the experimental groups.

Effectiveness of four different techniques in removing intracanal medicament from the root canals: An in vitro study

Aim:

To evaluate the effectiveness of different techniques in removing calcium hydroxide (Ca(OH)₂) from the root canal.

Materials and Methods:

Twenty-four freshly extracted mandibular premolars were instrumented using ProTaper rotary instruments. The teeth were longitudinally split into two halves, cleaned of debris. The two halves were then reassembled and filled with Ca(OH)₂ and were divided into four groups. In Group I, the teeth were irrigated with 5 mL of 2.5% sodium hypochlorite (NaOCl) and 5 mL of 17% of ethylenediaminetetraacetic acid. In Group II, the teeth were irrigated with 5 mL of 2.5% NaOCl and a rotary ProTaper F3 instrument was used. In Group III, the teeth were irrigated with 5 mL of 2.5% NaOCl and agitated using an ultrasonic unit. In Group IV, the teeth were irrigated with 5 mL of 2.5% NaOCl and a CanalBrush was used to remove Ca(OH)₂. The roots were disassembled, and photographs were taken. The amount of residual Ca(OH)₂ was calculated using an image analysis software as a percentage of the total canal surface area. The data were analyzed using one-way analysis of variance and post-hoc Tukey test.

Results:

CanalBrush and ultrasonic techniques showed significantly less residual Ca(OH)₂ than irrigants and rotary techniques. There was no significant difference between the rotary and irrigant techniques.

Conclusion:

None of the techniques used were completely able to remove Ca(OH)₂ from the root canals. But the CanalBrush and ultrasonic techniques were significantly better than the rotary instrument and irrigant groups.

The evaluation of two rotary instrumentation techniques under "operator-related variables" standardized conditions

Objective:

We aimed here to evaluate the enlargement characteristics of two nickel-titanium rotary instrument systems that use two different preparation techniques, in simulated root canals under “operator-related variables” standardized conditions.

Materials and Methods:

A total of 40 simulated canals in resin blocks were divided into two groups as the Mtwo group for use with a single-length technique and the ProTaper instrument system group for use with crown down technique. To standardize the operator-related variables, all preparations were carried out with a computer controlled device that was developed and used previously as described in a published study. The pre- and post-operative digital images of the canals were superimposed and measured at 11 levels from the apical tip. The distances between the pre- and post-operative outer lines of the root canals were measured at both the inner and outer sides of the curve. The amount of removed material and the symmetry of the preparations were evaluated. Statistical analyses were performed with Mann-Whitney test.

Results:

Significantly more material was removed by Mtwo at 9 levels and by ProTaper at 2 levels (P < 0.05) while no significant difference was determined at 11 levels. The preparations made with ProTaper were more symmetrical at 4 levels while no significant difference was determined at 7 levels.

Conclusion:

Mtwo removed significantly more material than ProTaper at different levels of the curved root canals. Mtwo and ProTaper made symmetrical preparations and maintained the original shape of the root canal at different levels under controlled operator-related variables.

CT evaluation of canal preparation using rotary and hand NI-TI instruments: An in vitro study

Background:

Controlled, uniformly tapered radicular preparation is a great challenge in endodontics. Improper preparation can lead to procedural errors like transportation of foramen, uneven dentine thickness, stripping of root canal, formation of ledge, zip, and elbow in curved canals. These procedural errors and their sequel can adversely affect the prognosis of treatment.

Aim/Objectives:

The present in vitro study aims to evaluate canal preparation based on the following factors: canal transportation, remaining dentine thickness and comparing centering ability between hand Ni-Ti K files and ProTaper rotary Ni-Ti instruments using computed tomography (CT).

Materials and Methods:

For evaluation, 30 mesiobuccal roots of maxillary molars were selected. Of these, 15 roots were distributed into two groups where Group 1 included hand instrumentation with Ni-Ti K-files; and Group 2 comprised ProTaper NiTi rotary system. Pre instrumentation and post instrumentation three-dimensional CT images were obtained from root cross-sections that were 1 mm thick from apex to the canal orifice; scanned images were then superimposed and compared.

Result:

It was observed that the manual technique using hand Ni-Ti K-file produced lesser canal transportation and maintained greater dentine thickness than the rotary ProTaper technique at middle and coronal third and this difference was statistically significant. No significant difference was seen with regard to canal transportation and remaining root dentine at apical levels. With regard to centering ratio, no significant difference was seen between both the groups at all levels.

Conclusion:

ProTaper should be used judiciously, especially in curved canals, as it causes higher canal transportation and thinning of root dentine at middle and coronal levels. None of the groups showed optimal centering ability.