Effect of Instrumentation Techniques and Preparation Taper on Apical Extrusion of Bacteria

Assessment of Stress Distribution with 3 Taper Design Preparation of Root Canal Using Finite Element Analysis

Aim

Present research was done to assess stress distribution in three different taper design preparation of root canal with the help of finite element analysis.

Materials and Methods

Lower incisors teeth having single canals that were cleaned and shaped with the help of NeoEndo Flex Titanium (NiTi) rotary file and later three designs were created such as 4%, 6%, and 8% canal preparation taper. Cone beam computed tomography (CBCT) was done for all teeth and subjected to finite element analysis for stresses. The collected data were statistically analyzed.

Results

Highest stress was found in the coronal followed by the middle and least in the apical part in all three designs. The highest stress value was found in enamel than dentin (MPa). The highest stress value was found with design 3 (8% taper) followed by designs 2 (6% taper) and 1 (4% taper) for enamel and dentin with either oblique or vertical stress loading.

Conclusion

All canals preparation exhibited maximum enamel stress at the coronal load points compared to apical and middle portions. The stress increases with increase in canal tapering.

Endodontic management of an aberrant germinated composite odontome: A case report

To describe the endodontic treatment of a germinated composite odontome with atypical internal anatomy. A 35-year-old male presented with pain in the left mandibular second molar region. Intraoral examination and Cone-Beam Computed Tomography (CBCT) revealed a rare case of a germinated composite odontome with a 3-2-1 Vertucci configuration in the mesial root. Occlusal morphology and mesial root configuration required modifications in methods of isolation and access cavity preparation. Contemporary tools like magnification, ultrasonics and controlled memory rotary files were essential for executing the treatment plan. The tooth was functional at 18 months follow up and radiographs revealed no abnormality.

Comparison of single and multiple file rotary endodontic instruments for debris and irrigant extrusion: An in vitro study

Aim

The aim of this study was to assess and compare the quantity of apically debris which was extruded apically by TruNatomy (TN), ProTaper Next (PTN), HyFlex electric discharge machining (EDM), and HyFlex controlled memory (CM), following root canal preparation.

Materials and Methods

Sixty extracted single-canal mandibular premolars were used. The root canal preparation was done with TN, HyFlex EDM, PTN, or HyFlex CM files. The preweight debris, which was extruded apically, was collected in the Eppendorf tube and later on incubated at 670°C for 3 days and weighed again to record the extruded debris.

Results

The result showed that there was a significant reduction in debris extrusion by TN system, followed by PTN system, HyFlex EDM, and maximum extrusion in HyFlex CM (P < 0.05). Between the PTN and TN groups as well as between the HyFlex EDM and HyFlex CM groups, statistically significant difference was not observed (P > 0.05).

Conclusion

Apical debris extrusion is the inherent nature of the all file systems. Nevertheless, the TN file system produced substantially minimum debris extrusion among other systems compared in the study.

Phenotypic Characterization and Antibiograms of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli Isolated at the Human-Animal-Environment Interface Using a One Health Approach Among Households in Wakiso District, Uganda

Background

The occurrence of extended spectrum beta-lactamase (ESBL) producing bacteria such as Escherichia coli has increasingly become recognized beyond hospital settings. Resistance to other types of antibiotics limits treatment options while the existence of such bacteria among humans, animals, and the environment is suggestive of potential zoonotic and reverse-zoonotic transmission. This study aimed to establish the antibiotic susceptibility profiles of the ESBL-producing Escherichia coli (ESBL-EC) from human, animal, and environmental isolates obtained among farming households within Wakiso district using a One Health approach.

Methods

A total of 100 ESBL-EC isolates from humans 35/100 (35%), animals 56/100 (56%), and the environment 9/100 (9%) were tested for susceptibility to 11 antibiotics. This was done using the Kirby-Bauer disk diffusion method according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Data were analyzed in STATA ver. 16 and graphs were drawn in Microsoft excel ver. 10.

Results

Most of the ESBL-EC isolates (98%) were resistant to more than two antibiotics. ESBL-EC isolates were most susceptible to meropenem (MEM) (88.0%), and imipenem (82.0%) followed by gentamicin (72%). ESBL-EC isolates from humans were most susceptible to meropenem (MEM) followed by imipenem (IPM)> gentamicin (CN)> ciprofloxacin (CIP). Animal samples were more susceptible to MEM, IPM, and CN but were highly resistant to cefotaxime (CTX)> cefepime (FEP)>other antibiotics. Multidrug resistance (MDR) was mostly reported among households keeping goats under intensive husbandry practices. Seven percent of the isolates exhibited carbapenem resistance while 22% showed aminoglycoside resistance. Similar resistance patterns among humans, animals, and environmental samples were also reported.

Conclusion

Our study provides baseline information on non-hospital-based MDR caused by ESBL-EC using a One Health approach. ESBL-EC isolates were prevalent among apparently healthy community members, animals, and their environment. It is important to conduct more One Health approach studies to generate evidence on the drivers, resistance patterns, and transmission of ESBL-producing organisms at the human-animal-environmental interface.

Quantitative evaluation of apically extruded debris using TRUShape, TruNatomy, and WaveOne Gold in curved canals

Objective

This study compared the quantity of extruded debris after instrumentation with TRUShape 3D Conforming files, TruNatomy files, and the WaveOne Gold reciprocating system.

Materials and methods

Fifty-one mesiobuccal canals with severe curvatures (25–40°) were assigned to three equal groups according to the rotary system used for preparation, either TRUShape, TruNatomy, or WaveOne Gold files. The extruded debris was collected in pre-weighed glass vials. The data were statistically analyzed using a one-way ANOVA test and Tukey’s post hoc test.

Results

The least extruded debris was obtained with the WaveOne Gold instruments compared to the TRUShape and TruNatomy files (p < 0.001).

Conclusions

Debris extrusion occurs independently of the motion or design of the instrument. The WaveOne Gold system outperformed TRUShape and TruNatomy files in this study.

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.

Comparison of Apical Extrusion of Bacteria After Glide Path Preparation Between Manual K File, One G Rotary, and WaveOne Gold Glider Reciprocation Preparations

Objective:

To compare the amount of apically extruded bacteria between hand-filed preparations, rotary and reciprocation glide path preparations in curved canals of extracted teeth infected with Enterococcus faecalis.

Methods:

Forty mandibular first molar teeth were decoronated, fitted into rubber stoppers and fixed onto glass vials. The mesiobuccal canals from mandibular first molar teeth were infected with Enterococcus faecalis, then randomly assigned to one of five groups for glide path preparation: manual stainless-steel file (K-files), rotary file (One G), reciprocating file (WaveOne Gold Glider) and two control groups. After glide path preparation, 0.01 mL of saline was taken from the experimental vials. The solution was plated on tryptic soy agar and colonies of bacteria were counted as colony-forming units. The results were analysed statistically using Kruskal-Wallis and post hoc Mann-Whitney U tests.

Results:

The manual K-file group was associated with significantly more bacteria extrusion compared to the rotary and reciprocating groups (P<0.05). However, no significant difference occurred between rotary and reciprocation instruments.

Conclusion:

All instrumentation techniques resulted in a measurable amount of apical extrusion of bacteria. Manual K-files extruded the highest quantity of bacteria compared to One G rotary file and WaveOne Gold Glider reciprocation file during glide path preparation.

Evaluating In Vitro Performance of Novel Nickel-Titanium Rotary System (TruNatomy) Based on Debris Extrusion and Preparation Time from Severely Curved Canals

INTRODUCTION

This laboratory-based study aimed to investigate the quantitative amount of apically extruded debris from severely curved root canals and the preparation time for the novel rotary system TruNatomy (TN; Dentsply Sirona, Charlotte, NC) compared with Reciproc Blue (RCB; VDW Dental, Munich, Germany), HyFlex (HyFlex Controlled Memory [HCM; Coltene/Whaledent, Altstatten, Switzerland] and HyFlex EDM [HEDM, Coltene/Whaledent]), and ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland) rotary systems.

METHODS

One hundred mandibular molar human teeth with severe curvature of the mesiobuccal canal (25°-45°) were included in the present study. The specimens were randomly distributed into 5 balanced groups (n = 20): TN, RCB, HCM, PTN, and HEDM. The amount of extruded debris for each group during instrumentation at body temperature was collected in an Eppendorf tube. After desiccation, the mean debris weights for each group were calculated. The total preparation time for each group was also recorded. Data were statistically analyzed using the Kruskal-Wallis test at a significance level of P < .05.

RESULTS

The HCM and HEDM groups extruded a significantly higher amount of debris than the other tested groups (P < .001). TN extruded the least amount of debris, but it was not significantly different compared with the RCB and PTN groups (P > .05). In terms of preparation time, the TN group did not show any significant difference compared with the other groups.

CONCLUSIONS

All instrumentation systems extruded debris. TN was among the groups that produced the lowest amount of apically extruded debris that is clinically acceptable. The amount of apically extruded debris using the TN system was equal to 2 popular systems and statistically significantly less than 2 other popular systems studied.

Effect of Different Host-Related Factors on Postoperative Endodontic Pain in Necrotic Teeth Dressed with Interappointment Intracanal Medicaments: A Multicomparison Study

Objectives  The current study aimed to assess the impact of factors such as age, gender, and the tooth type on postoperative endodontic pain in necrotic teeth with symptomatic periapical periodontitis and radiolucency dressed randomly with either calcium hydroxide or propolis paste.

Materials and Methods  The standard chemomechanical root canal preparation of 80 teeth was performed by the primary investigator. The intracanal medicaments were inserted by the secondary operator. Patients self-recorded their postoperative endodontic pain intensity with the help of visual analog scale at 4, 12, 24 (day 2), 48 (day 3), and 72 (day 4) hours. During analysis, patients (68/80) were grouped according to gender, age, and the tooth type.

Statistical Analysis  Mann–Whitney’s U test was applied for mean pain score comparison between genders and between tooth type. Kruskal–Wallis’ test was applied for mean pain score comparison between the age groups.

Results  No significant difference ( p > 0.05) in pain scores was found between the age groups and between the tooth types. Males had significantly higher pain scores as compared with females at days 2 ( p = 0.035), 3 ( p = 0.023), and 4 ( p = 0.020).

Conclusion  The results suggested that there was no impact of age and tooth types on postoperative endodontic pain.

Can kinematics, file diameter, and PUI influence the intracanal decontamination and apical bacterial extrusion?

The present study investigated the intracanal decontamination and apical extrusion of bacteria and debris from root canals instrumented with rotary and reciprocating systems (ProDesign Logic or ProDesign R), with different file diameters and using conventional syringe irrigation (CSI) or passive ultrasonic irrigation (PUI). Eighty extracted mandibular premolars were contaminated with Enterococcus faecalis and randomly assigned to eight experimental groups according to the root canal instrumentation and irrigation technique employed (n = 10): G1: Prodesign Logic 25.06; G2: Prodesign R 25.06; G3 and G4 were instrumented with the same single-file systems, respectively, using 35.05 diameters and CSI. G5, G6, G7, and G8 were instrumented like the previous groups, but with PUI. Apically extruded debris during instrumentation was collected into pre-weighed microtubes. The weight of the empty microtube was subtracted from the final weight to establish the amount of extruded debris. Bacteria from root canals and extruded debris were collected for a microbiological evaluation of colony forming units (CFU/mL). For statistical analyses, the Mann-Whitney and Kruskal-Wallis followed by the Dunn's tests were used (α = 0.05). All instruments caused extrusion of debris. For irrigation techniques, PUI promoted greater debris and bacterial extrusion (p < 0.05). The CFU/mL count indicated that the instrumentation of the experimental groups were equally effective in the decontamination of the root canal (p > 0.05). The systems tested (regarding file diameter and kinematics) were associated with similar amounts of apically extruded debris and root canal decontamination. PUI was associated with greater debris and bacterial extrusion.

Apically extruded debris produced during glide path preparation using R-Pilot, WaveOne Gold Glider and ProGlider in curved root canals

The present study aimed to compare the apically extruded debris produced during glide path preparation using R-Pilot (RP), WaveOne Gold Glider (WGG) and ProGlider (PG) with the subsequent preparation using Reciproc Blue in curved root canals. Mesial roots of mandibular molars with angle of curvature between 25° and 35° were selected (n = 20). The Myers and Montgomery method was used to collect and assess apically extruded debris. The glide path was prepared either manually with K-file, ProGlider, R-Pilot or WaveOne Gold Glider. Manual preparation group produced the highest amount of apically extruded debris (P < 0.05), while all groups caused debris extrusion. There were no significant differences among the extruded debris caused by RP, PG and WGG groups (P > 0.05). Apically extruded debris produced by engine-driven reciprocational or continuous rotational single file glide path instruments was similar, whereas manual glide path preparation was associated with the greatest amount of extruded debris.

Effect of Chinese Propolis as an Intracanal Medicament on Post-Operative Endodontic Pain: A Double-Blind Randomized Controlled Trial

Propolis is a potent anti-microbial and natural anti-inflammatory by-product obtained from the beehive. Studies have demonstrated the superior biocompatibility and anti-microbial properties of propolis as compared to calcium hydroxide. However, its effect on postoperative endodontic pain is unknown. Therefore, this study aimed to investigate the impact of Chinese propolis paste as an intracanal medicament on postoperative endodontic pain intensities compared with calcium hydroxide (control) at different time intervals in necrotic teeth with periapical radiolucency. Eighty patients with single-rooted necrotic teeth with visible periapical radiolucency were recruited and randomly allocated to either the calcium hydroxide or propolis groups. After chemo-mechanical preparation and intracanal medicament insertion, patients were given the VAS (visual analogue scale) to record pain scores. Inter-group data were compared and analyzed using two-way repeated measure ANOVA (Bonferroni test). A p-value of < 0.025 was considered significant. In total, >78% of the patients experienced no or only mild post-operative pain in both the groups at all time intervals, without any significant difference in pain scores between the two groups (p > 0.025). An overall flare-up rate of 14.8% was found. The results suggest that either of these medicaments can be used as an inter-appointment medication for the prevention of postoperative pain in necrotic cases.

Assessment of toxicity and oxidative DNA damage of sodium hypochlorite, chitosan and propolis on fibroblast cells

The objective of this study was to evaluate and compare the cytotoxicity and genotoxicity on human fibroblast cell lines of sodium hypochlorite (NaOCl), chitosan and propolis as root canal irrigating solutions. Human fibroblast cells were exposed to chitosan, propolis and NaOCl for 4 and 24 h. Cell viability was assessed by 2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide, and oxidative DNA damage was assessed by determination of 8-hydroxydeoxyguanosine (8-OHdG) level with an ELISA kit. The data of cell cytotoxicity were analysed statistically using a test of one-way analysis of variance at a significance level of p < 0.05. In the NaOCI group, the 8-OHdG level was higher than in the chitosan group, but there was no statistical difference when compared with the other groups (p < 0.05). It was determined that the irrigation solutions were cytotoxic, depending on the dose and time. NaOCl was the most toxic solution after both 4 and 24 h of exposure (p < 0.05). Chitosan and propolis may be alternatives to NaOCl for irrigation solutions, because they are both less toxic and produce less oxidative DNA damage.

Quantitative Assessment of apically Extruded Bacteria using different Instrumentation Techniques and Preparation Taper

BACKGROUND

Cleaning and shaping of the pulp canal is one of the most important steps of endodontic therapy. Serious complications occur by the apical extrusion of bacteria during the instrumentation procedures. Both crown-down (CD) and full-length linear motion (FM) techniques are routinely used as a component of taper rotary instrument procedures for achievement of thorough cleaning and shaping of the pulp canal space. Hence, we aimed for this study to assess the change in the amount of apically extruded bacteria using CD and FM instrumentation techniques produced by differences in taper between the instruments used during biomechanical preparation of root canals.

MATERIALS AND METHODS

The present study included assessments of 132 extracted maxillary central incisor teeth. To achieve a uniform teeth length of 21 mm, the height of the tooth crown was reduced for preserving the coronal portion of teeth. A modified glass vial model was constructed for the estimation of amount of bacterial extrusion through the apical region. For filling of each pulp canal specimen, 20 mL of Enterococcus faecalis suspension was used followed by the use of a number 10 K-file for carrying the bacteria down the lengths of pulp canals. All the contaminated teeth specimens were divided into six study groups with groups I to III containing specimens prepared in the CD manner, while groups IV to VI contained specimens prepared in the FM manner. Six teeth were taken as negative control with three specimens with each technique, and another six specimens were taken as positive controls. Cultivable bacterial counts were determined by evaluating 100 mL saline solution from each vial followed by its inoculation on blood agar. All the colony-forming unit (CFU) values were log-transformed (base 10), and the results were analyzed by Statistical Package for the Social Sciences software.

RESULTS

A significantly lower quantity of CFU values was observed during CD instrumentation procedures with 0.02 files in comparison with all other study groups. However, while comparing both the instrumentation procedures when different taper files, other than 0.02 taper, were used for biomechanical preparation of root canal, nonsignificant results were obtained.

CONCLUSION

With 0.02 taper preparations, significantly less amount of extrusion of bacteria is associated when done with CD technique.

CLINICAL SIGNIFICANCE

No change in the amount of apical extrusion of bacteria will be seen by changing the type of instrumentation procedures. Amount of bacteria extruded can be minimized using 0.02 taper. Key words: Bacteria, Instrumentation, Taper.