The efficacy of the Self-Adjusting File versus WaveOne in removal of root filling residue that remains in oval canals after the use of ProTaper retreatment files: A cone-beam computed tomography study

Does the presence of full-coverage crown interfere with removal of obturation material: A cone-beam computed tomography image segmentation volumetric analysis

Aim

The aim of this study was to assess and compare the influence of the presence of full-coverage crown on the obturation material removal efficiency of different retreatment file systems.

Materials and Methods

Sixty extracted, human, maxillary premolars were accessed, instrumented, and obturated with gutta-percha and AH Plus sealer. The samples were scanned with cone-beam computed tomography and volume of obturating material was measured using ITK-SNAP volumetric software. Samples were divided (n = 30) into with and without all metal full-coverage crown groups. Each group was then subdivided into three subgroups (n = 10) based on retreatment file used (ProTaper URS, HyFlex Remover, and NeoEndo). The volume of remnants of obturating material was remeasured by image segmentation using ITK-SNAP volumetric software. One-way analysis of variance, followed by the Tukey's post hoc test, was used for data analysis, with a significance level of 5%.

Results

A significant difference in percentage remnant of obturating material after retreatment file was observed on overall comparison between with (29.84%) and without crown (21.79%) groups (P < 0.05). Each file system removed significantly more obturating material in without crown samples than with crown samples (P < 0.05). The percentage remnant of obturating material after retreatment file use was as follows: ProTaper URS > NeoEndo retreatment file > HyFlex Remover. All file systems showed significantly different (P < 0.05) efficiency in removal of obturating material.

Conclusions

None of the retreatment file systems were able to remove obturating material completely. The presence of full-coverage crown negatively impacted the efficiency of retreatment files for the removal of obturating material. HyFlex Remover performed better than NeoEndo which was better than ProTaper URS.

Evaluation of the efficacy of TruNatomy, ProTaper retreatment, and RaCe file systems in retreatment of moderately curved mandibular molars: An in vitro study

Context

Endodontic retreatment is the first line of treatment in cases of failed primary endodontic treatment. Although associated with challenges such as incomplete removal of obturating material, increased clinical time, and extrusion of apical debris, endodontic retreatment still has considerable success rate in the general population.

Aims

The aim of this study was to evaluate and compare the efficacy of TruNatomy, ProTaper retreatment, and RaCe file systems to remove the obturating material, time taken to remove the obturating material, and apical extrusion of debris using cone-beam computed tomography (CBCT).

Settings and Design

In vitro study.

Subjects and Methods

Forty-five moderately curved mesiobuccal roots of the mandibular molars were instrumented up to #25, 4% taper and obturated with bioceramic sealer and lateral compaction technique. Teeth were divided randomly into three groups (n = 15). Teeth were retreated with TruNatomy, ProTaper retreatment, and RaCe file systems, respectively. Preretreatment and postretreatment CBCT scans were recorded and percentage of obturating material removed was calculated. Time taken to remove the obturating material and apical extrusion of debris was noted.

Statistical Analysis Used

Descriptive statistics including percentage, mean, standard deviation, Tukey's post hoc test, Kruskal-Wallis test, and Mann-Whitney Post hoc test were used.

Results

The total time needed for the removal of obturating material was comparatively shorter in the RaCe group, followed by the ProTaper retreatment group and TruNatomy group (P < 0.001). TruNatomy files were significantly better in removing the obturating material than the ProTaper retreatment files (P = 0.04). Statically, no difference between RaCe and TruNatomy files was noted. Apically extruded debris was more in the TruNatomy group than in the RaCe and ProTaper retreatment groups (P = 0.01).

Conclusions

All tested endodontic files were effective in removal of obturating material, although none could completely remove the filling material and no system could completely eliminate apical extrusion.

The Efficacy of Two Novel Retreatment Systems in the Removal of Root Canal Obturating Materials (An In vitro Study)

BACKGROUND: The complete removal of root filling material is one of the main goals of non-surgical endodontic retreatment. Thus, the development of new techniques and instruments aiming to promote this task presents clinical significance. AIM: The purpose of the study was to assess the amount of residual root canal filling materials (gutta-percha/sealer) after using two different endodontic retreatment systems and ultrasonic tip. METHODS: Forty-five mandibular premolar teeth were mechanically instrumented and obturated. Retreatment was performed using two different Endostar RE (Group 2), Rogin retreatment system (Group 3), and ultrasonic tip (Group 1). Roots were separated buccolingually into two halves. A digital camera connected to the stereomicroscope captured images to each half. Image-J software was used to evaluate and measure the areas with remaining filling material in each third (cervical, middle, and apical). RESULTS: Data analysis revealed significant differences between the groups in the coronal, middle, and apical thirds (p < 0.05). The ultrasonic retreatment tips (G1) were significantly more efficient in removing the gutta-percha and sealers compared to the Rogin (G3) and Endostar (G2) retreatment endodontic kits. CONCLUSIONS: All the file systems left some filling material in the canals. Ultrasonic retreatment tip had maximum efficacy for the removal of filling materials in comparison with the retreatment file systems under investigation.

A Comparative Study of the Efficacy of WaveOne and NeoEndo Retreatment File System for the Removal of Gutta Percha from the Root Canal

BACKGROUND

Teeth with apical periodontitis that either persisted or developed after initial root canal treatment is most often indicated for retreatment procedure. The present study was conducted to compare the WaveOne and NeoEndo retreatment file system for the removal of gutta-percha from the root canal.

MATERIALS AND METHODS

Fifty extracted mandibular first premolars with single straight roots were divided into two groups, Group I-WaveOne and Group II-NeoEndo. All samples were scanned with cone-beam computed tomography after the root filling and retreatment procedures. The decrease in the volume of filling material after each retreatment protocol was measured.

RESULTS

The mean volume of gutta-percha in Group I before retreatment was 5.6 and in Group II was 5.3, after retreatment in Group I was 2.7, and in Group II was 4.2. The mean percentage reduction in Group I was 45.2% and in Group II was 23.8%. The difference was significant (P < 0.05).

CONCLUSION

Both systems failed to completely remove gutta-percha. WaveOne was significantly more effective than the NeoEndo retreatment system.

Critical analysis of research methods and experimental models to study removal of root filling materials

Despite enjoying high favourable outcome rates, root canal treatment is not always successful. Root canal retreatment is a widely practised option for managing a non-healing root treated tooth. A basic distinction between retreatment and initial treatment is the requirement to remove the existing root filling material occupying the root canal space. Only then, can the technical deficiencies and possible causes of failure be addressed. Hence, the successful removal of the root filling material is critical to achieving the objectives of retreatment. Many different materials and techniques have been used for root canal filling, which have been documented in a plethora of studies; these are mainly laboratory studies investigating the removal of root filling materials. To help guide future research, which may then better inform clinical practice in relation to retreatment procedures, the focus of this narrative review is on the research methods and experimental models employed to study the removal of root filling materials. The current available literature demonstrates great variation in the research methodologies used to study the removal of root filling material, including direct visualization by splitting tooth samples or clearing, three-dimensional radiographic imaging including using microcomputed tomography or cone-beam computed tomography, and a combination of these techniques. Depending on the research method employed, variation also exists in quantification of root filling material removal; these include measurements of surface area, volume or weight, and criteria-based (semi-quantitative) assessment. Experimental models, using human teeth or resin models, differ with respect to standardization techniques and replication of the clinical scenario including initial sample preparation, canal filling, allocation and technical aspects of retreatment procedures. Future models should replicate, as closely as possible, the clinical scenario. Currently, microcomputed tomography provides a highly detailed, non-invasive and non-destructive method of objectively assessing and quantifying root filling removal.

Impact of Contracted Endodontic Access Cavity on Shaping Ability of Hyflex Electrical Discharge Machining Single File Using Cone Beam Computed Tomography: An Ex Vivo Study

AIM: The aim of the study was to evaluate and compare the effect of different access cavity designs, using cone-beam computed tomography (CBCT), on root canal transportation, and centralization performed on two rooted maxillary premolars. METHODS: Twenty maxillary premolars were randomly divided into two groups. In Group 1, traditional endodontic cavities (TECs) were prepared. In Group 2, contracted endodontic cavities (CECs) were prepared. Mechanical preparation was done by HyFlex electrical discharge machining (EDM) single file in both groups. CBCT imaging was performed pre- and post-root canal preparation for calculations of root canal transportation and centering ability. RESULTS: Data were analyzed using Mann–Whitney U test and Kruskal–Wallis test. For transportation, teeth with CECs showed the statistically significantly highest median amount of transportation, while as for centering ability, results showed no significant difference between both groups. CONCLUSION: Under the conditions of this study, HyFlex EDM prepared canals with different access cavity designs without significant shaping errors. TEC showed less transportation than CEC, while both TEC and CEC had no effect on the file centering ability.

Efficacy of reciprocating and rotary retreatment nickel-titanium file systems for removing filling materials with a complementary cleaning method in oval canals

Objectives

This study aimed to evaluate and compare the efficacy of the S1 reciprocating system and the D-Race retreatment rotary system for filling material removal and the apical extrusion of debris.

Materials and Methods

Sixty-four freshly extracted maxillary canines were shaped with size 10 and size 15 K-files, instrumented using ProTaper Gold under irrigation with 2.5% sodium hypochlorite (NaOCl), obturated according to the principle of thermo-mechanical condensation with gutta-percha and zinc oxide eugenol sealer, and allowed to set for 3 weeks at 37°C. Subsequently, the teeth were divided into a control group (n = 4), the D-Race rotary instrument group (n = 30), and the S1 reciprocating instrument group (n = 30). After classical retreatment, the canals were subjected to a complementary approach with the XP-Endo Shaper. Desocclusol was used as a solvent, and irrigation with 2.5% NaOCl was performed. Each group was divided into subgroups according to the timing of radiographic readings. The images were imported into a software program to measure the remaining filling material, the apical extrusion, and the root canal space. The data were statistically analyzed using the Z-test and JASP graphics software.

Results

No significant differences were found between the D-Race and S1 groups for primary retreatment; however, using a complementary cleaning method increased the removal of remnant filling (p < 0.05).

Conclusions

Classical removal of canal filling material may not be sufficient for root canal disinfection, although a complementary finishing approach improved the results. Nevertheless, all systems left some debris and caused apical extrusion.

Biomechanical preparation in primary molars using manual and three NiTi instruments: a cone-beam-computed tomographic in vitro study

PURPOSE

To evaluate nickel-titanium rotary systems, ProTaper Universal (PTU), ProTaper Next (PTN), self-adjusting file (SAF), and stainless steel hand K files in deciduous root canals in longitudinal and horizontal sections by three-dimensional reconstruction. Whether there was any difference in shaping ability, transportation, dentine removal, untouched canal surface area, and preparation time among the different groups when used in primary root canals.

METHODS

Shaping and cleaning of canals in primary molars were done using the four systems, and CBCT and specialized software were used for scanning, image processing, three-dimensional reconstruction, and analysis of pre-operative and post-operative to evaluate the groups for their shaping properties, transportation, amount of dentine removal, untouched canal surface area, and preparation time in primary root canals.

RESULTS

None of the groups reported stripping of canals or instrument failure. SAF demonstrated less removal of dentine as compared to other groups. Hand K files presented with high untouched canal surface area, while it was least with SAF. In addition, rotary files provided faster preparation than hand files, and among the rotary systems, PTN took least time for cleaning and shaping of canals. All the groups were similar in transportation at cervical and apical third.

CONCLUSION

Under the conditions of this study, SAF seemed to result in more conservative and meticulous removal of dentine. This is desirable to preserve the integrity of thin-walled primary root canals. SAF also showed less untouched canal areas suggesting better contact with the primary canal walls. The rotary file groups required less clinical time which is important in paediatric treatments.

Efficacy of Controlled Memory and Shape Memory Nickel Titanium Instruments in Removing Filling Material from Severely Curved Root Canals: An Ex Vivo Study

Introduction

The aim of the present study was to compare the efficacy of four NiTi instruments with different properties (shape memory and control memory), in both rotary and reciprocating motions, during retreatment procedures.

Methods and Materials

Mesial canals of thirty-two mandibular molars were instrumented, obturated, and then scanned with" Cone-beam Computed Tomography" (CBCT). Teeth were randomly divided into 4 groups (n=8) according to each system: "Shape Memory" (SM) instruments including Reciproc (R25 file) and ProTaper Next (X3 and X2 file), "Controlled Memory" (CM) instruments including WaveOne Gold (Primary file) and Hyflex (30.06 and 25.06 file). The specimens were rescanned after retreatment procedures. The volume of the residual material left inside the canals, the operating time and the fractured files were analyzed. ANOVA and student t-tests were used for statistical analysis.

Results

There were no significant differences in the percentage of the residual filling material or requiring time amongst different groups of instruments (P>0.05). However, CM instruments presented the highest frequency of fractured files [2 SM instruments (12.5%) and 7 CM instruments (43.75%)] with a significant difference (P=0.023).

Conclusions

This ex vivo study showed that CM and SM instruments can remove filling materials from mandibular mesial root canals during retreatment procedures; nonetheless the CM instruments had a higher frequency of fractured files. No system was able to completely remove the filling materials. Therefore, additional procedures and techniques are needed to improve root canal cleanliness.

Efficacy of rotary and reciprocating single-file systems on different access outlines for gutta-percha removal in retreatment: An in vitro study

Introduction:

The aim of this study is to compare the effectiveness of reciprocating and continuous rotary nickel-titanium instruments during retreatment performed through two different access outlines.

Methodology:

A total of 48 freshly extracted mandibular first and second premolars with single root and canal were selected. Initial root canal treatment was completed through a contracted endodontic cavity (CEC) design. Canals were instrumented with F2 ProTaper instrument, obturated with warm lateral condensation of gutta-percha with AH Plus sealer, and allowed to set for 30 days at 37°C and 100% humidity. For retreatment, specimens were divided into two groups (n = 24) on the basis of access outline, CEC or traditional endodontic cavity. Retreatment was initiated using ProTaper Retreatment instruments (D1–D3). Specimens were further divided (n = 12) and reinstrumented up to Neoniti 25/0.08 or WaveOne 25/0.08. Irrigation was performed using 3% sodium hypochlorite and 17% ethylene diamine tetraacetic acid. Retreatment time was recorded. Teeth were sectioned and photographed, and the percentage of remaining obturation material was measured.

Results:

Data were collected, and statistical analysis was performed using one-way analysis of variance and Tukey honestly significant difference multiple post hoc procedures (P < 0.05).

Conclusion:

None of the systems completely removed the root filling material from root canals. However, ProTaper/Neoniti instruments removed more GP when compared to Protaper/WaveOne instruments with both the access outlines. Both the instruments with traditional access outline required less time for removal of obturating material when compared to CEC.