Debris extrusion during root canal preparation with nickel-titanium instruments using liquid and gel formulations of sodium hypochlorite in vitro

Influence of pretreating radicular dentin with different polyacrylic acids and isopropanol on the retention of posts

STATEMENT OF PROBLEM

The optimal pretreatment of radicular dentin before cementing a post with glass ionomer cement is unclear.

PURPOSE

The purpose of this in vitro study was to evaluate the retention of prefabricated tapered titanium posts to endodontically treated teeth after applying different pretreatment protocols on the radicular dentin.

MATERIAL AND METHODS

The coronal part of 32 single-rooted human teeth was removed 1-mm coronally to the cemento-enamel junction. All specimens received endodontic treatment, and the root canals were prepared with an instrument to a depth of 10 mm to receive a titanium post. The dentin walls of each specimen were roughened with a hand-held diamond cutting instrument. The specimens were randomly divided according to the surface treatments into 4 groups (n=8): KW: etched with 20% to 30% polyacrylic acid (PAA) (Ketac Conditioner) and rinsed with water; KWI: etched with 20% to 30% PAA, rinsed with water and 70% isopropanol; DW: etched with 30% to 50% PAA (Durelon Liquid) and rinsed with water; DWI: etched with 30% to 50% PAA, rinsed with water and 70% isopropanol. The prefabricated titanium posts were airborne-particle abraded and cemented with glass ionomer cement. The specimens were fixed in custom-made brass cylindrical holders with autopolymerizing acrylic resin with the holder parallel to the long axis of the post. All specimens were stored in water for 3 days at 37 °C. Retention was evaluated using a tensile test with a universal testing machine (Zwick Z010) at a crosshead speed of 2 mm/min. Data were statistically analyzed with a 1-way ANOVA, followed by the Tukey post hoc test for pairwise comparisons between groups (α=.05).

RESULTS

Mean ±standard deviation retention values ranged from 201.8 ±55.5 N (KW) to 328.1 ±70.9 N (DWI). Groups DWI and KWI (316 ±58.3 N) showed statistically higher retention values than group KW (P<.05) but did not significantly differ from retention values obtained in group DW (P>.05).

CONCLUSIONS

An additional final rinse with isopropanol after using PAA increased the retention of the post significantly for all groups. Although group DWI achieved the highest retention values, pretreatment of radicular dentin as in group KWI may also be considered.

Disinfection Efficacy of Laser Activation on Different Forms and Concentrations of Sodium Hypochlorite Root Canal Irrigant against Enterococcus faecalis in Primary Teeth

Photoactivated disinfection with sodium hypochlorite (NaOCl) has improved primary root canal treatment outcomes. This in vitro study aims to assess and compare the disinfecting efficacy of 2.5% sodium hypochlorite solution and 5.25% sodium hypochlorite gel, without laser activation and accompanied by laser activation, on Enterococcus faecalis-contaminated primary teeth root canals. After one month of incubating extracted teeth specimens with E. faecalis, 36 specimens were randomly divided into two groups: Group A (conventional method without laser-activated irrigation) and Group B (with laser-activated irrigation). Each group was further divided into three subgroups, with six samples in each subgroup. Subgroup 1 received irrigation with normal saline, Subgroup 2 with 2.5% sodium hypochlorite solution, and Subgroup 3 with 5.25% sodium hypochlorite gel. Diode laser activation at 810 nm was used in Group B. Bacterial colony counts were measured before and after the intervention. Student's t-test and one-way analysis of variance (ANOVA) with Tukey's post hoc test were used for statistical analysis. The significance level was set at p < 0.05. Microbial analysis revealed no bacterial growth in samples irrigated with 5.25% sodium hypochlorite gel activated with the laser. Activation with the laser significantly (p = 0.02) improved the disinfection ability of the irrigant compared to the non-activation group. The disinfection ability of sodium hypochlorite gel was better than that of saline (p = 0.02); however, it was comparable to that of sodium hypochlorite solution (p = 0.67). Conclusion: Root canal irrigation with 5.25% sodium hypochlorite gel activated with an 810 nm diode laser resulted in complete eradication of Enterococcus faecalis, indicating its effectiveness as an endodontic disinfection treatment modality.

The use of sodium hypochlorite mixed with etidronic acid during canal preparation increases debris extrusion

The purpose of this study was to compare the impact of different irrigation protocols on debris extrusion. Single-rooted teeth were distributed into groups based on the irrigation protocols (n = 40): 2.5% NaOCl (biomechanical preparation: 20 mL and final irrigation: 5 mL); 2.5% NaOCl (biomechanical preparation: 20 mL) + 17% EDTA (final irrigation: 2 mL) + 2.5% NaOCl (final irrigation: 3 mL); and a mixture of 5% NaOCl +18% HEDP (biomechanical preparation: 20 mL and final irrigation: 5 mL). The canals were prepared using a reciprocating instrument size 40/0.06. For final irrigation, the groups were reassigned based on the agitation methods (n = 10): (a) no agitation; (b) ultrasonic; (c) sonic; and (d) continuous rotation. The control group (n = 10) received saline solution without agitation. The amount of debris extruded was measured by weight and analysed using One-way ANOVA (α < 0.05). The subgroups treated with NaOCl + HEDP mixture showed a significantly higher amount of extruded debris (p < 0.05), while there was no difference among agitation methods in all groups (p > 0.05).

In vitro evaluation of filling material removal and apical debris extrusion after retreatment using Reciproc blue, Hyflex EDM and ProTaper retreatment files

OBJECTIVES

To evaluate the amount of remaining filing material and apical debris extrusion after retreatment using Reciproc Blue, Hyflex EDM and ProTaper Retreatment Files.

MATERIALS AND METHODS

Thirty-six extracted permanent mandibular first molars with moderately curved mesial roots were selected. Mesiobuccal canals were prepared using the ProTaper Next system up to size X2 and filled using gutta-percha and Adseal sealer via cold lateral compaction. Teeth were randomly divided into three equal groups (n = 12): Group 1: Reciproc Blue (RB)(VDW, Germany), Group 2: Hyflex EDM (HEDM)(Coltene/Whaledent, Switzerland), Group 3: ProTaper Universal Retreatment file system + ProTaper Next file system (PTUR + PTN)( Dentsply Maillefer, Switzerland). Eppendorf tubes were used to collect the apically extruded debris. Cone-beam computed tomographic scans were taken prior to and after retreatment and the volume of remaining filling material was assessed at the coronal, middle and apical levels. Statistical analysis was performed using the Kruskal-Wallis test, Friedman's test and Wilcoxon Sign Rank test. Significance level was set at p value 0.05.

RESULTS

There were no statistically significant differences among the three groups in the reduction of the volume of the filling material or in the amount of apically extruded debris.

CONCLUSION

All the tested filing systems showed similar efficacy in removing the filling material, however, none of them could achieve its complete removal. Apical extrusion of debris occurred with all the systems used with no significant difference between the three groups.

Impacts of different Nickel-Titanium rotary and reciprocating root canal preparation systems on the amount of apically extruded debris

This study aimed to evaluate the amount of apically extruded debris caused by different NiTi files. One hundred mandibular premolars were included in this study. The specimens were divided into five groups (n = 20): (i) TruNatomy, (ii) WaveOne Gold, (iii) 2Shape, (iv) ProTaper Next and (v) Reciproc Blue. The extruded debris was collected into preweighed Eppendorf tubes. These tubes were weighed again, and the net weight of debris was calculated. Data were statistically analysed, and the significance level was set at 5%. The least amount of extruded debris was observed in the TruNatomy group (p < 0.05). Statistically significant differences were not found among (iii), (iv) and (v) groups (p > 0.05). However, these groups resulted in significantly higher amounts of debris when compared to (i) and (ii) groups (p < 0.05). The results lead us to conclude that all instrumentation systems caused apical extrusion of debris at varying weights.

Influence of access cavity design, sodium hypochlorite formulation and XP-endo Shaper usage on apical debris extrusion - A laboratory investigation

This study assessed the amount of apically extruded debris during root canal preparation using XP-endo shaper and the supplemental use of XP-endo finisher comparing the use of traditional endodontic access or conservative endodontic access cavities and liquid or gel-based formulations of 5.25% sodium hypochlorite or distilled water as supplemental agents. Maxillary first premolar teeth (N = 148) were randomly divided based on their access cavity design and sub-grouped according to the supplemental agent used. The amount of extruded debris was analysed based on the dry weight of the debris collected using a previously established laboratory methodology. Debris extrusion occurred in all groups. Overall, the traditional endodontic access cavity design was associated with more debris extrusion compared to the conservative type. The use of sodium hypochlorite solution showed higher debris extrusion than the gel, whilst distilled water had intermediate values.

Advances in the Role of Sodium Hypochlorite Irrigant in Chemical Preparation of Root Canal Treatment

Irrigation of root canal system is of great significance to the success of endodontic treatment, where sodium hypochlorite (NaOCl) is the most widely used irrigant in chemical preparation. NaOCl functions by eliminating bacterial biofilms and dissolving organic tissue, which may vary according to several factors such as the microbiology of root canal infection and the concentration of the irrigant. It has been proposed that the effectiveness of NaOCl could be enhanced via several methods, including heating the irrigant, applying in conjunction with certain reagents, or activating by agitation techniques. Despite its antibacterial and tissue-dissolving capacities, NaOCl should be used with caution to avoid detrimental effect due to its cytotoxicity and negative effect on dentin properties. In this narrative review, we discussed the factors that affect the properties of NaOCl, the methods to improve its efficacy, and the side effects that might occur in clinical practice.

Comparison of apical debris extrusion of different generation nickel-titanium instrument systems

BACKGROUND AND AIM

The aim of this study is to evaluate the apical debris extrusion amounts and preparation times of four different nickel-titanium systems with a similar cross-section design-Mtwo, RECIPROC, RECIPROC blue, and VDW.ROTATE.

MATERIALS AND METHODS

Eighty human mandibular central incisors were divided into four equal groups (n = 20). The test apparatus was inserted into an assembly that provided root canal temperature. Preparation times were recorded using a stopwatch, and the amount of extruded debris was collected in pre-weighed Eppendorf tubes. After drying, the net amount was determined by subtracting the previously measured Eppendorf tube weights from the total weight.

RESULTS

The Mtwo had the largest amount of debris, but there was no significant difference among the other groups. The VDW.ROTATE completed the preparation in a significantly shorter time than the RECIPROC blue and Mtwo.

CONCLUSION

Compared to other files, the Mtwo sequence produced significantly more debris and required significantly more time to complete the whole root canal preparation.

Influence of Sodium Hypochlorite and Chlorhexidine on the Dynamic Cyclic Fatigue Resistance of XP Endo Shaper Instruments

OBJECTIVE

 This study evaluated the dynamic cyclic fatigue resistance of the XP-Endo Shaper (XPS), associated with chlorhexidine digluconate (CHX) or sodium hypochlorite (NaOCl) in two different formulations: gel (G) or liquid (L).

MATERIALS AND METHODS

 Sixty XPS were used in an artificial stainless-steel canal, and the files were fully immersed in the irrigating solution throughout the experiment until the fracture. The files were divided into six groups (n = 10) based on the irrigation solution used: NaOCl(L), NaOCl(G), CHX(L), CHX(G), natrosol gel (NAT) (control), and lubricating oil (LO) (control). The artificial canal was manufactured 1.5 mm wide, 20 mm long, and, 3.5 mm deep with a straight cervical segment measuring 14.29 mm; an apical segment of 4.71 mm with 3 mm radius; and 90 degrees of curvature apical 1 mm long straight segment. Resistance to cyclic fatigue was determined by recording the number of cycles to fracture (NCF).

RESULTS

 The CHX(G), CHX(L), and OIL (LO) groups showed no significant difference between them and presented longer time to fracture (p > 0.05). NaOCl(L) shows the lowest NCF without significant differences between NaOCl(G) and NAT. The NCF of the NaOCl(G) was statistically similar to the CHX(L) and statistically lower than the CHX(G) and OIL groups. NAT did not present a statistical difference of the NaOCl(L), NaOCl(G), and presented a significantly lower NCF than the CHX(G) (p < 0.01).

CONCLUSION

 The use of CHX(G) resulted in increased cyclic fatigue resistance of the XPS instruments compared to NaOCl or LO.

Apically Extruded Debris in Curved Root Canals Using a New Reciprocating Single-File Shaping System

INTRODUCTION

The present study addresses the influence of 5 different shaping file systems on apical debris extrusion (AED) using 2 different irrigation protocols.

METHODS

One hundred fifty mandibular first permanent molars were divided into 2 groups and 10 subgroups. The mesial root canals were shaped using One Reci (MicroMega), WaveOne Gold Primary (Dentsply Sirona, York, PA), and ProTaper Next (Dentsply Sirona) using reciprocating motion and One Curve (MicroMega) and ProTaper Next using continuous rotation. The first group and the second one were respectively irrigated with 10 and 5 mL distilled water.

RESULTS

When the same instrumentation technique was used, the G10 mL subgroups showed statistically lower AED than the G5 mL subgroups (P < .05). The One Reci and One Curve subgroups, in both groups, produced statistically lower AED than the remaining subgroups.

CONCLUSIONS

The cross section of the instrument could be the main parameter in determining the amount of AED. The irrigation volume used during the shaping procedure might affect the amount of AED.

Apical debris extrusion of full-sequenced rotary systems in narrow ribbon-shaped canals

The apically extruded debris caused by TruNatomy System (TRN), RACE EVO system (RE) and VDW Rotate (VR) systems in mandibular anterior teeth with ribbon-shaped root canals were compared. The root canals (n = 20 in each group) were irrigated with NaOCl 2.5%, and the extruded debris was collected at pre-weighted Eppendorf tubes. The amount of apically extruded debris (mg) and the treatment time (s) were recorded. Tukey pairwise comparisons were performed to compare groups with a 95% confidence level. VR had significantly less debris extrusion values and treatment time than RE and TRN (P < 0.05). Although no difference was observed between RE and TRN in terms of apically extruded debris (P > 0.05), a significant difference in favour of RE was observed in terms of treatment time (P < 0.05). All the instruments extruded debris at varying weights.