The principles of techniques for cleaning root canals

Efficacy of various techniques in calcium silicate-based intracanal medicament removal: a micro-CT analysis

The purpose of this study was to evaluate the efficacy of different techniques in removing calcium silicate intracanal medicament (Bio-C Temp). Forty human single-canaled premolars were randomly distributed into five groups (n = 8). All root canals were instrumented, then filled with Bio-C Temp. Following 1-week incubation, the intra-canal medicament was removed using one of five techniques according to tooth group: conventional syringe irrigation, Endo Activator, passive ultrasonic irrigation (PUI), ProTaper Universal F3 and XP-endo Finisher (XPF). Micro-CT scanning was performed before and after removal of Bio-C Temp. All techniques significantly reduced the volume of Bio-C Temp (p < 0.001) without reaching complete elimination. The percentage of Bio-C Temp removed was significantly higher in the XPF group (98.2%) compared to conventional syringe irrigation (70.6%), the Endo Activator (75.7%), and the ProTaper Universal (76.6%). There was no significant difference between the XPF and PUI (95.1%) groups. None of the removal techniques were able to completely remove Bio-C Temp from the root canal. However, XPF was the most effective method, but was not statistically significant when compared to PUI. Clinical Relevance: This study demonstrated that both XPF and PUI outperform conventional irrigation in removing Bio-C Temp intracanal medicament.

Prevalence of Apical Periodontitis in Saudi Arabia: A Systematic Review and Meta-analysis

Objective

This systematic review was aimed to assess the prevalence of apical periodontitis (AP) in Saudi Arabia, focusing on individual-level prevalence and the frequency of AP in endodontically versus untreated teeth.

Methods

This review followed the PRISMA guidelines and involved searches in several databases, including PubMed-MEDLINE, Cochrane-CENTRAL, and EMBASE, without date restrictions until August 19th, 2023. Eligibility criteria encompassed studies using CBCT, panoramic, and periapical radiographs to diagnose AP in the Saudi population. The meta-analysis employed a random-effects model due to high heterogeneity among studies.

Results

From 359 records, 13 studies were included, indicating a 40% prevalence of AP in individuals and a 6% prevalence across all teeth within the Saudi population. Root canal-treated teeth demonstrated a higher prevalence at 47%. The data revealed a substantial prevalence of AP compared to global averages, with first molars being the most affected. Studies showed moderate risk of bias and significant heterogeneity.

Conclusion

The high occurrence of AP in Saudi Arabia, particularly in root-treated teeth, emphasizes the need for enhanced endodontic care and more accurate diagnostics. Urgent improvements in dental health policies and further research are essential to understand AP's impact and improve oral health outcomes.

A Comparative Evaluation of Antimicrobial and Cytotoxic Efficacy of Biosynthesized Silver Nanoparticles and Chemically Synthesized Silver Nanoparticles Against Enterococcus faecalis: An In Vitro Study

Introduction Effective root canal cleaning and sealing are essential for a successful endodontic procedure. For the purpose of disinfecting root canals, both herbal and non-herbal medications are recommended. This study aimed to analyze the antimicrobial and cytotoxic properties of biosynthesized silver nanoparticles (AgNPs) synthesized from Azadirachta indica/neem and chemically synthesized AgNPs from trisodium citrate (TSC) against oral pathogens to be further used as an irrigant in endodontic treatment. Materials and methods To synthesize A. indica AgNPs, powdered fresh A. indica leaves were weighed, added to double distilled water, heated for 30 minutes, and then combined with silver nitrate solution. TSC was also used to create TSC AgNPs. X-ray diffraction (XRD), scanning electron microscopy (SEM), ocular observation, and the ultraviolet-visible light (UV-vis) spectrum were used to characterize the AgNPs. Studies were conducted on the extract's characteristics, including its cytotoxicity and antibacterial activity. Results The hue shift and peak on the UV-vis spectrophotometer were signs that AgNPs were forming. The XRD pattern showed that the sample included crystalline AgNPs, mostly spherical ones. By using SEM, the presence of AgNPs was also verified. AgNPs that were synthesized showed antimicrobial efficacy against Enterococcus faecalis. Compared to chemically synthesized AgNPs, A. indica AgNPs showed lower minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values, a bigger zone of inhibition (ZOI), and less cytotoxic action. Conclusion This study demonstrates the minimal cytotoxicity and antibacterial activity of A. indica AgNPs against E. faecalis. This suggests that they might also be employed as root canal cleaners. Before experimenting with animals or cell lines in clinical trials for endodontic treatment, further research should be done.

Expert consensus on irrigation and intracanal medication in root canal therapy

Chemical cleaning and disinfection are crucial steps for eliminating infection in root canal treatment. However, irrigant selection or irrigation procedures are far from clear. The vapor lock effect in the apical region has yet to be solved, impeding irrigation efficacy and resulting in residual infections and compromised treatment outcomes. Additionally, ambiguous clinical indications for root canal medication and non-standardized dressing protocols must be clarified. Inappropriate intracanal medication may present side effects and jeopardize the therapeutic outcomes. Indeed, clinicians have been aware of these concerns for years. Based on the current evidence of studies, this article reviews the properties of various irrigants and intracanal medicaments and elucidates their effectiveness and interactions. The evolution of different kinetic irrigation methods, their effects, limitations, the paradigm shift, current indications, and effective operational procedures regarding intracanal medication are also discussed. This expert consensus aims to establish the clinical operation guidelines for root canal irrigation and a position statement on intracanal medication, thus facilitating a better understanding of infection control, standardizing clinical practice, and ultimately improving the success of endodontic therapy.

Cyclic Fatigue of Different Reciprocating Endodontic Instruments Using Matching Artificial Root Canals at Body Temperature In Vitro

Reciprocating motion expands the lifetime of endodontic instruments during the preparation of severely curved root canals. This study aimed to investigate the time to fracture (TTF) and number of cycles to failure (NCF) of different reciprocating instruments (n = 20 in each group) at body temperature using a dynamic testing model (amplitude = 3 mm). Reciproc Blue (RPB), size 25/.08, WaveOne Gold (WOG) 25/.07, Procodile (Proc) 25/.06, R-Motion (RM_06) 25/.06 and R-Motion (RM_04) 30/.04 instruments were tested in their specific reciprocating motion in artificial matching root canals (size of the instrument ± 0.02 mm; angle of curvature 60°, radius 5.0 mm, and centre of curvature 5.0 mm from apical endpoint). The number of fractured instruments, TTF, NCF, the and lengths of the fractured instruments were recorded and statistically analysed using the Chi-Square or Kruskal-Wallis test. Both TTF (median 720, 643, 562, 406, 254 s) and the NCF (3600, 3215, 2810, 2032, 1482 cycles) decreased in the following order RM_06 > RPB > RM_04 > Proc > WOG with partially significant differences. During testing, only six RM_06 instruments fractured, whereas 16/20 (RPB), 18/20 (Proc), and 20/20 (RM_04, WOG) fractures were recorded (p < 0.05). Within the limitations of the present study, blue-coloured RPB and RM instruments exhibited a significantly superior cyclic fatigue resistance compared to SE-NiTi and Gold-wire instruments. Heat treatment, cross-sectional design and core mass significantly influenced the longevity of reciprocating instruments in cyclic dynamic testing.

Effect of Heat Treatment on Mechanical Properties of Nickel-Titanium Instruments

INTRODUCTION

The aim of this study was to evaluate the torsional resistance, cyclic fatigue resistance, and bending stiffness of nickel-titanium (NiTi) file systems with different heat treatments and cross-sectional designs.

METHODS

WaveOne Primary treated with memory-triple (MT) heat treatment (WOMT) was compared with WaveOne Primary (WO) and WaveOne Gold Primary (WOG). Torsional resistance test was performed using a customized device, and the distortion angle, ultimate strength, and toughness were evaluated. For cyclic fatigue resistance test, the instruments were reciprocated with continuous 4 mm up-and-down movement until fracture in a customized device, and the time to fracture was compared. Fracture surfaces of each group were examined under the scanning electron microscope. Bending stiffness was measured using a custom-made device. The results were analyzed using one-way analysis of variance and the Tukey's post hoc comparison at a significance level of 95%.

RESULTS

WOMT showed higher ultimate strength and toughness than the other systems (P < .05). WOMT also showed highest cyclic fatigue resistance among the tested groups (P < .05). WO had the highest bending stiffness than others, whereas WOMT had a larger residual angle than others (P < .05).

CONCLUSIONS

This new MT heat treatment technique makes NiTi file more flexible and improves its mechanical properties. In addition, the effect of heat treatment on flexibility was found to be more significant than that of the cross-sectional area.

Comparative evaluation of antifungal activity of Sodium Hypochlorite, Calcium Hypochlorite and modified Salt Solution associated with passive ultrasonic irrigation against Candida albicans - An In-Vitro study

Aim

The study evaluated the antifungal activity of sodium hypochlorite (NaOCl), calcium hypochlorite (Ca(OCl)2), and modified salt solution (MSS) assisted with passive ultrasonic irrigation against Candida albicans.

Materials and Methods

One hundred and thirty-six single-rooted premolars were decoronated and enlarged up to a file #45, autoclaved, inoculated with C. albicans, and incubated for 72 h. The samples were randomly distributed into eight groups (n = 17) according to the protocol for decontamination G1: No treatment, G2: Distilled water (DW), G3: 2.5% NaOCl, G4: 2.5% NaOCl + ultrasonic activation (US), G5: 2.5% Ca(OCl)2, G6: 2.5% Ca(OCl)2 + US, G7: MSS, G8: MSS + US. Microbiological testing (Colony forming Unit [CFU] counting) was performed before and after the treatment.

Statistical Analysis

Data were subjected to the one-way analysis of variance followed by the Tukey's post hoc test (P < 0.05).

Results and Conclusion

Groups 1 and 2 showed the highest mean contamination (5.41 and 4.31 log10 CFU/mL, respectively), which was statistically different from all the other groups (P < 0.001). G4 showed the lowest mean contamination (0.24 log10 CFU/mL) with statistically significant value (P < 0.001). 2.5% NaOCl with ultrasonic activation can aid in significant fungal reduction. Ultrasonic activation of 2.5% NaOCl, 2.5% Ca(OCl)2, and MSS was also found to have improved antifungal activity against C. albicans.

A critical evaluation of physical and manufacturing properties of genuine and counterfeit rotary nickel-titanium endodontic instruments

BACKGROUND

Rotary nickel-titanium (NiTi) instruments are made to exacting standards and are costly to manufacture, and quality control is paramount. Consequently, unauthorized factories make counterfeit instruments that are less expensive and may therefore be attractive to dentists. Little information exists about the metallurgy and manufacturing quality of such instruments. There is the potential for counterfeit instruments to be at higher risk of fracture during treatment, thereby compromising clinical outcomes. The aim of this study was to evaluate physical and manufacturing properties of genuine and counterfeit ProTaper Next™ and Mtwo® rotary NiTi instruments.

METHODS

This study investigated the metallurgical properties, manufacturing quality, microhardness and number of cycles to failure of two commonly used rotary NiTi systems and compared them with counterfeit products purporting to be genuine articles.

RESULTS

Counterfeit instruments were found to be inferior in manufacturing standards and were less resistant to cyclic fatigue when compared to genuine instruments.

CONCLUSIONS

Counterfeit rotary NiTi instruments may be less efficient at preparing root canals and may be at higher risk of fracture during endodontic treatment. Dentists must be aware that, although less expensive, counterfeit instruments may be of dubious manufacturing quality and at higher risk of fracture if used in patients. © 2023 Australian Dental Association.

Factors Associated with Patients' Rejection of Root Canal Treatment in a Tertiary Hospital, Southwest Nigeria: A Pilot Survey

Objective

Root canal treatment (RCT) is a major procedure in dentistry. It aims to relieve the pain of pulpal origin and maintain the affected tooth as a functional unit on the arch. Despite these achievable goals, RCT is sometimes rejected by patients. This study, therefore, sought to assess the reasons for rejection in patients planned for endodontic/RCT.

Materials and Methods

This was a cross-sectional pilot survey of patients planned for RCT using a self-administered questionnaire. The questionnaire included sociodemographics, the Index for Dental Anxiety and Fear (IDAF-4C), and questions to assess the reasons for rejection of endodontic treatment. Data collected were analysed with IBM Statistical Package for the Social Sciences software program, version 23.0. Descriptive statistics were used; chi-square was used to test the association between categorical variables. Statistical significance was set at P ≤ 0.05.

Result

Thirty-one patients between the age range of 16 and 81 years, with a mean age of 38.16 ± 17.87, participated in the survey. Only nine (29.03%) of the participants declined to have the treatment. The majority 6(66.7%), and 7(77.8%) of those that refused the treatment did so, due to fear of drilling (P = 0.014) and cost of treatment (P = 0.001), respectively. Mean IDAF-4C was 1.86 ± 0.9 (standard deviation).The rejection was, however, not affected by past experience, the risk of taking multiple radiographs, and the number of hours or visits for the procedure.

Conclusion

The cost of treatment and fear of drilling were the major reasons for the rejection of RCT in this study. Therefore, there is a need to further look into making endodontic treatment a more comfortable, less costly, and less fear-provoking procedure for patients.

Comparative Evaluation of Fracture Resistance of Endodontically Treated Teeth Instrumented With K3XF Rotary Files Using Different Tapers

AIM

To compare the effect of different tapers of the K3XF file system on the fracture resistance of endodontically treated mandibular premolars obturated with a three-dimensional (3-D) obturation system.

METHODOLOGY

For the study, 80 freshly extracted human mandibular premolars with single well-developed roots without any curvatures were taken and the tooth roots were wrapped in a single layer of aluminum foil, and they were placed vertically in a plastic mold filled with self-curing acrylic resin. The access was opened, and working lengths were determined. The canals were instrumented keeping an apical size of #30 by different taper rotary files: Group 1: un-instrumented (control group), Group 2: 30/.04, Group 3: 30/.06, Group 4: 30/.08 K3XF file system, and teeth were obturated using a 3-D obturation system, and access cavities were filled using composite. Both experimental and control groups were subjected to fracture load using a conical steel tip (0.5mm) attached to a universal testing machine to record force applied in newton until root fracture.

RESULTS

Root canal instrumented groups showed lower fracture resistance than the uninstrumented group.

CONCLUSION

Hence it could be concluded that endodontic instrumentation with increased taper rotary instruments caused a decrease in fracture resistance of the teeth, and biomechanical preparation of root canal system with rotary or reciprocating instruments caused a significant decrease in fracture resistance of endodontically treated teeth (ETT), thereby decreasing their prognosis and long-term survival.

Histological Investigation of the Cleaning Effectiveness of Different Biomechanic Processes of Isthmus in Lower Molars

Objectives This study aimed to evaluate the efficacy of different instruments (Hyflex, ROTATE, and hand files) and irrigation methods (EndoUltra, EndoActivator, and side-perforated syringe) in the mesial root canal of a mandibular first molar with isthmuses.

Materials and Methods Sixty-three mandibular molar teeth with isthmus were selected using cone beam computed tomography (CBCT) images. The root canals were instrumented with Hyflex, ROTATE, or hand files (21 of each) and three of each as control group and the specimens were embedded in silicone blocks. Final irrigation was performed with the perforated syringe or ultrasonic (EndoUltra) or sonic irrigation (EndoActivator). All canals were irrigated using 5.25% NaOCl solution (15 mL). Then, the roots were stained with hematoxylin–eosin, and specimens were sliced for histologic evaluation. The isthmus regions (2.7, 3, 4.7, and 5 mm from the apex) were analyzed, and the percentage of debris was calculated.

Statistical Analysis All data were statistically analyzed using one-way analysis of variance and Tukey's tests.

Results Both Hyflex and ROTATE groups showed less debris compared with the hand instrument group (P < 0.05). When irrigation methods were compared, EndoUltra showed the least, followed by EndoActivator and perforated needle irrigation having the maximum debris (p < 0.05). When sections were compared, the maximum debris was found in the apical section and the least in the coronal section (p < 0.05).

Conclusion Although none of the methods cleaned the isthmus completely, nickel–titanium (NiTi) systems and ultrasonic and sonic systems removed more debris than the side-perforated needle syringe irrigation.

Evaluation of the Canal Transportation Following Glide Path Preparation with Different Rotary Systems: A Comparative Study

Objectives. Ideal root canal shaping might be more challenging particularly in cases with severely curved canals or complex anatomical variations. Glide path preparation is suggested as a critical step to achieve ideal canal preparation. The present study is aimed at evaluating transportation at different levels of the canal following glide path preparation by five different path finders. Materials and Methods. The study was conducted on 100 S-shaped canal simulator blocks. Glide path was prepared in five groups including (1) Scout RaCe (#10 and #15, 0.02), (2) One G (#14, 0.03), (3) PathFile (#13 and #16, 0.02), (4) GPS (#15, 0.03), and (5) K file (#15, 0.02) (Control group). The first four groups were NiTi rotary instruments, while the last group was a stainless steel hand file. The aforementioned files were used after canal negotiation by a #10 stainless steel hand file. Before- and after-preparation photos were taken and were superimposed in Adobe PhotoShop CC 2019. Transportation measurements were conducted in Digimizer. Absolute canal transportation was calculated at 10 cross-sections. Intergroup and intragroup data analysis were conducted using one-way and repeated measures ANOVA tests, respectively, in SPSS 26.0. The significance level was set to 0.05. Results. Although K file led to significantly more transportation in the apical and middle thirds ( $p<0.001$ ), rotary groups were not statistically different. In the coronal third, K files led to significantly more transportation compared to Scout RaCe and PathFile ( $p<0.05$ ). Conclusion. Within the limitations of the present study, regardless of the recruited rotary system, glide path preparation using NiTi rotary instruments leads to less canal transportation compared to stainless steel hand files.

Evaluation of Curved Canal Transportation Using the Neoniti Rotary System with Reciprocal Motion: A Comparative Study

The ideal root canal preparation is where the original canal morphology is maintained during the biomechanical preparation. Preparation of curved canals has always been a challenge to clinicians. Better results have been suggested for a single NiTi instrument with reciprocating motion than the conventional continuous rotation method in the preparation of curved root canals. Although the Neoniti rotary system is not suggested to be used with reciprocal motion, running a pilot study, we found that it could be possible. The present study aimed to investigate if shaping curved canals using the Neoniti rotary system with reciprocal motion leads to better results in terms of root canal transportation. One hundred acrylic j-shape canal simulator endoblocks were used in this study. Five preparation sequences were applied: GPS followed by A1#20 (GPS + A1#20), GPS followed by A1#20 and then A1#25 (GPS + A1#20 + A1#25), GPS followed by A1#25 (GPS + A1#25), hand file followed by A1#20 (hand file + A1#20), and GPS followed by A1#20 (with reciprocal motion) (GPS + A1#20(reciprocal)). Pictures were taken from blocks once before and once after preparation from two dimensions. Before-and-after pictures were superimposed in Photoshop software. Measurements were performed in Digimizer. The number of autoreverses and pecking motions was recorded after reviewing the recorded videos. Data were analyzed in SPSS, version 26. A p value of less than 0.05 was considered statistically significant. The group GPS + A1#20 + A1#25 had more transportation compared with the others, at apical, middle, and coronal thirds not only in the frontal view but also in the lateral view. Other groups were not significantly different. The number of peckings and autoreverses was significantly less when A1#25 was used after GPS and A1#20. When A1#20 was used with reciprocal motion, it had less peckings compared with the same file with continuous rotation, and no autoreverses were observed in that group. Using Neoniti files with reciprocal motion might result in less instrument fatigue and favorable results, with respect to canal anatomy preservation. Using A1#20 before A1#25 also will decrease the stress on the instrument during preparation. However, this may lead to significantly more canal transportation.

A Comparative evaluation of the shaping ability, canal straightening, and preparation time of five different NiTi rotary files in simulated canals

Aim

The aim is to compare the shaping ability, canal straightening, and the preparation time of five different nickel-titanium rotary files in simulated J-shaped canals.

Materials and Methods

Ninety J-shaped canals in resin blocks were filled with 2% Methylene Blue solution and pre-instrumentation images were taken using a Leica microscope at a ×10. They were prepared until size 25 taper 0.04 using (n = 18 per group): T-Flex, HyFlex CM, Vortex Blue, S5, and iRace. After instrumentation, images were captured again, and composite images were made using Adobe Photoshop imaging software. The differences in canal width and canal curvature at each respective landmark were measured and compared. The preparation time and canal abbreviations were also recorded. Statistical analyses were performed using one-way ANOVA and post hoc Tukey HSD tests. The level of statistical significance was set to P = 0.05.

Results

HyFlex CM demonstrated the least difference in canal width after instrumentation, but no significant difference (P > 0.05) as compared to T-Flex and Vortex Blue. The mean canal straightening ranged between 0.91° and 7.65°. T-Flex created the least canal straightening after instrumentation which was significantly less (P < 0.05) than S5, but there was no significant difference (P > 0.05) when compared to HyFlex CM. Instrumentation with the S5 file was significantly faster (P < 0.05), whereas HyFlex CM was the slowest.

Conclusion

T-Flex, HyFlex CM, and Vortex Blue demonstrated better shaping ability, whilst T-Flex and HyFlex CM maintained the original canal curvatures well. S5 tended to straighten the canals and caused the greatest canal transportation, but it required the least amount of time to shape the canal.

Antimicrobial and physical properties of experimental endodontic sealers containing vegetable extracts

To assess the antimicrobial activity and the physical properties of resin-based experimental endodontic sealers with the incorporation of vegetable extracts obtained from Bixa orellana, Mentha piperita, and Tagetes minuta species. The extracts were obtained and characterized by gas chromatography-mass spectrometry (GC–MS), and minimum inhibitory concentration (MIC) against Streptococcus mutans, Enterococcus faecalis, and Candida albicans. The extracts were individually incorporated into a dual-cure experimental sealer at a mass concentration of 0.5%. A commercial reference RealSeal was used. The sealers were evaluated by measuring the setting time, degree of conversion, dimensional stability, radiopacity, flow, and film thickness of these materials, also and its antimicrobial effect was evaluated using the direct contact test. Data were statistically analyzed by analysis of variance and Tukey’s post-hoc test at α = 0.05 significance level. The physical properties were not influenced by the addition of the vegetable extracts (p > 0.05). For S. mutans, only T. minuta and B. orellana groups presented antibacterial activity after 24 h of contact (p < 0.05). All extracts evidenced an antibacterial effect against E. faecalis (p < 0.05). The experimental sealers hold promise as a novel vegetable sealer with great antimicrobial activity and also great physical–mechanical properties. Nonetheless, more studies are needed.

Filling quality of several obturation techniques in the presence of apically separated instruments: A Micro-CT study

Separated root canal instruments may affect the quality of root canal obturation and hence the survival of endodontically treated teeth. Obturation techniques may influence filling-quality. The aim was to evaluate the obturation quality of teeth filled with different obturation techniques in the presence of apically separated instruments using micro-computed tomography (μ-CT). Notched ProTaper F2 rotary-files were separated in the apical third of 36-human mandibular incisors with single root/canal and mature apex. Samples were filled by an endodontist according to one of the following obturation techniques (n = 12): cold lateral-compaction (CLC), single-cone (SC) and thermoplastic injection (TI). Samples were scanned by the Skyscan 1,274® μ-CT device after 1-week at 37°C in 100% humidity. Images of the sections were evaluated with CTan software in terms of total-volume and volume percentage of the filling materials and voids between coronal end of the separated instrument and gutta-percha/sealer filled void-free sections. Data was analyzed using Kruskal-Wallis and Mann Whitney-U tests with a significance level of 5%. Kruskal-Wallis revealed differences among groups (p < 0.05).Pairwise comparisons revealed that less volume of voids were measured in SC (0.02 ± 0.03 mm³ ) compared to CLC (0.15 ± 0.16 mm³ ) and TI (0.18 ± 0.24 mm³ ) (p < 0.05); while TI was statistically similar with CLC (p > 0.05). Percentages of volumes of voids and filling materials were as follows for SC, CLC and TI, respectively: 8.88 ± 18.52% and 24.45 ± 38.40%, 46.92 ± 33.53% and 53.07 ± 33.53%, 40.54 ± 33.85% and 42.79 ± 34.45%. The obturation technique may have a significant impact on the volume of voids in the presence of a separated file. No obturation technique produced a void-free root canal filling.

Contemporary Cleaning of the Root Canal System

This article provides a contemporary synopsis of effective cleaning of the root canal system, an essential stage of root canal treatment. It provides a clinical update on the current state of knowledge on cleaning of the root canal system, and presents an outline of essential theory and practical tips for achieving effective and safe cleaning of the root canal system.

Chemical constituent, minimal inhibitory concentration, and antimicrobial efficiency of essential oil from oreganum vulgare against Enterococcus faecalis: An in vitro study

Aim:

The purpose of this study was to determine the chemical composition of oregano essential oil, minimal inhibitory concentration (MIC) and to assess its antimicrobial efficiency against Enterococcus faecalis.

Material and Methods:

Gas Chromatography and Mass Spectrometry (GC-MS) was used to determine the chemical composition of essential oil from oreganum vulgare. Broth dilution and agar diffusion method was used to evaluate the MIC. For Broth dilution, 100 μL of different concentration of oil (6.25, 12.5, 25.0, 50.0, and 100 μg/ml) was tested. Agar diffusion method was utilized to evaluate the antimicrobial efficiency of different concentration of oil (25.0, 50.0, and 100 μg/mL) against E. faecalis.

Results:

GC-MS analysis revealed that oregano essential oil contained carvacrol (41.2%), γ-terpinene (12.68%), p-cymene (9.47%), α-terpinene (1.19%) as the major compounds and β–caryophyllene (0.83%), β-linalool (0.67%), β–bisabolene (0.601%), α-pinene (0.6%), β-pinene (0.5%), terpinen-4-ol (0.41%), borneol (0.4%), 3-thujene (0.4%), spathulenol (0.4%), myristicin (0.25%), and apiol (0.14%). The results of the present study reported Oregano essential oil possess antimicrobial activity against E. faecalis. The MIC was 25 μg/ml and the minimum bacterial concentration (MBC) was 50 μg/ml.

Conclusion:

Oregano essential oil was reported to be an effective antimicrobial agent against E. faecalis. The MIC was found to be 25 μg/ml and the MBC was found to be 50 μg/ml.

Antibacterial Efficacy of Muringa Seed Extract and Potato Peel Extract Against Enterococcus faecalis

BACKGROUND

Elimination of infection and prevention of reinfection should be the main goal in the treatment of apical periodontitis. The most challenging part of endodontics is the complete disinfection of root canal system. Herbal alternatives have emerged as the more biofriendly approach in root canal irrigation and disinfection.

AIM AND OBJECTIVE

The aim of this study was to evaluate the antimicrobial efficacy of natural extracts like muringa seed and potato peel extract against Enterococcus faecalis.

MATERIALS AND METHODS

The antimicrobial activity was determined using agar diffusion test. The solutions were divided into three groups: Group I- Muringa seed extract, Group II- potato peel extract, and Group III-5.25% sodium hypochlorite. The zones of inhibition of growth were recorded. The strain used for this study was Enterococcus faecalis ATCC 29212.

RESULTS AND CONCLUSION

Muringa seed extract (Group I) demonstrated the best result among the tested solutions. Although there was no significant difference between potato peel extract (Group II) and 5.25% sodium hypochlorite (Group III). Within the limitations of this study, herbal extracts tested has shown significant antimicrobial action against Enterococcus faecalis.

Comparison of Shaping Ability of Different Single-File Systems Using Microcomputed Tomography

OBJECTIVES

 To evaluate the shaping ability of four different single-file systems using micro-computed tomography (micro-CT).

MATERIALS AND METHODS

 Eighty mesiobuccal and mesiolingual canals of permanent mandibular molars were randomly assigned to four groups according to the file used; WaveOne Gold, RECIPROC Blue, HyFlex EDM, and One Shape (n = 20). The samples were scanned using micro-CT for the preinstrumentation record; then the canals were instrumented and scanned for the postinstrumentation records.

STATISTICAL ANALYSIS

 The data were then analyzed statistically using one-way analysis of variance (ANOVA) with the level of significance set at α = 0.05.

RESULTS

 The results of canal centering ratio and canal transportation showed that no significant difference was found among the four file groups at the middle and the coronal levels. However, a significant difference was found at the apical level (p < 0.05), where WaveOne Gold showed the best centering ratio and the least amount of canal transportation. The change in the canal volume was significant at the coronal level (p < 0.05), whereas the change in the canal volume was higher for the HyFlex EDM group than the other groups. No significant difference was found between the other groups at the apical level, middle level, or in the total percentage of canal volume.

CONCLUSION

 WaveOne Gold produced a more centralized canal preparation with a lesser amount of transportation at the apical level. HyFlex EDM showed the highest canal volumetric change at the coronal level. The interim design of the endodontic files has a high impact on the behavior of the file inside the root canal.

Influence of Different Irrigation Solutions and Instrumentation Techniques on the Amount of Apically Extruded Debris

OBJECTIVE

The objective of the present study was to evaluate the influence of different irrigation solutions on the amount of extruded residues apically, varying the instrumentation technique in manual, continuous rotation, or reciprocation motions. The amounts of residue for each irrigation solution was also assessed.

METHODS

Two tests were performed. In the first test, 90 mandibular premolars were divided into nine groups (n=10). Each group was subjected to a different technique: ProTaper Universal, WaveOne Gold, or manual instruments, with different irrigation solutions [2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX) gel, or distilled water]. During the preparation of the root canal, the apically extruded material was collected in previously weighed glass vials. In the second test, irrigation solutions were weighed separately with the same weighing method. Data were analyzed using the Kolmogorov-Smirnov, one-way and two-way ANOVA, Levene, Tukey, and Games-Howell tests.

RESULTS

Apically extruded debris was observed in all groups. ProTaper Universal with continuous rotation using 2% CHX gel resulted in the greatest amount of debris (P<0.001). There were significant differences in the amounts of residue among the different groups (P<0.001). Moreover, when the weighing of the irrigation solutions was tested, the 2.5% NaOCl solution produced the greatest amount of residues compared with other irrigation solutions.

CONCLUSION

Different irrigation solutions influenced the amount of apically extruded debris during the preparation of the canal among the different instrumentation techniques. The ProTaper technique using 2% CHX gel resulted in the greatest amount of apically extruded debris.

Force and vibration generated in apical direction by three endodontic files of different kinematics during simulated canal preparation: An in vitro analytical study

During root canal shaping, pain could result from the high level of force or vibration generated. This could be related to file kinematics or geometry. In the present study, a comparison is made between forces and vibrations generated by endodontic files having three different kinematics. Square pillar resin blocks were used as simulated root canals to study forces and vibrations generated by the file having reciprocating motion (WaveOne Gold), transline motion (Self-Adjusting File), and rotary motion (2Shape). The forces and vibrations were measured using the dynamometer and accelerometer, respectively. Recorded time domain signals were processed in MATLAB to calculate the root mean square value. A one-way analysis of variance and Tukey's test for post hoc comparison at 95% confidence interval were applied over the root mean square data of different files. From a statistical analysis of the file systems, the null hypotheses could not be accepted (P < 0.05) as 95% of the confidence interval. Differences between the means were statistically significant. The root mean square values of force and vibration for WaveOne Gold significantly exceeded those of Self-Adjusting File, 2Shape1, and 2Shape2 while the root mean square values of vibration for 2Shape1 and 2Shape2 were significantly less than the Self-Adjusting File; however, the root mean square value of force for the 2Shape2 was significantly more than for the Self-Adjusting File. Under the present experimental conditions, significant differences in the root mean square values of force and vibration of the three endodontic files of different kinematics have been observed. The WaveOne Gold file system generated higher apical force and vibration than the transline and rotary file system.

Comparison between the Effectiveness of Rotary and Manual Instrumentation in Primary Teeth: A Systematic Review

Aim

To develop a scientifically current and evidence based protocol on the efficacy of rotary and hand root canal instrumentation in primary teeth.

Materials and methods

Previous randomized control trials were used for the current review. Hand search and online search engines of PUBMED and Google Scholar were used to search English language articles with human subjects published up to December 2016.

Results

After screening of the abstracts and articles, based on the inclusion and exclusion criteria a total of 13 articles were included in the systematic review.

Conclusion

Rotary instrumentation shows equivalent cleaning efficiency than hand files depending on the system of instrumentation and techniques used. However, use of rotary in primary teeth leads to improved shaping of canals providing better quality of treatment in less time.

How to cite this article

Panchal V, Jeevanandan G, et al. Comparison between the Effectiveness of Rotary and Manual Instrumentation in Primary Teeth: A Systematic Review. Int J Clin Pediatr Dent 2019;12(4):340–346.

Effect of glide path preparation on apical extrusion of debris in root canals instrumented with three single-file systems: An ex vivo comparative study

Aim:

The aim of this study was to test the effect of new protocol of glide path preparation by 20/0.04 rotary file on apical extrusion of debris when instrumenting fine curved mesial canals in mandibular molars with Self-adjusting File (SAF) and compare it to a glide path prepared by 20/0.02 hand K-file and rotary OneShape (OS) and reciprocating WaveOne (WO) file instrumentation.

Materials and Methods:

Sixty mandibular molars with curved mesial roots were selected and randomly divided into three groups (n = 20) for instrumentation. In two groups, glide path was prepared using 20/0.02 K-file for instrumentation by OS (size 25/0.06 taper) and WO (size 25/0.08 taper) files; in the remaining group, 20/0.04 rotary file was used for glide path preparation and instrumented by SAF (1.5 mm). The debris extruded during instrumentation was collected in preweighed Eppendorf tubes and stored in an incubator at 70°C for 5 days. Tubes containing the dry extruded debris were then weighed. One-way analysis of variance (ANOVA) was applied to the weights obtained, followed by Tukey's post hoc test for multiple comparison.

Results:

The mean debris (g) extruded apically was 0.000651 ± 0.000291, 0.000823 ± 0.000319, and 0.000473 ± 0.000238 for Group 1 (20/0.02 + OS), Group 2 (20/0.02 + WO), and Group 3 (20/0.04 + SAF), respectively. The groups exhibited a significant difference (P < 0.01; ANOVA). Group 3 resulted in least debris extrusion compared to Groups 1 and 2 (P < 0.01; Tukey's post hoc test).

Conclusion:

Glide path prepared to size 20/0.04 and SAF 1.5 mm instrumentation produce less debris in curved mesial canals of mandibular molars, compared to glide path established by 20/0.02 and instrumentation by OS and WO files.

Preservation of root canal anatomy using self-adjusting file instrumentation with glide path prepared by 20/0.02 hand files versus 20/0.04 rotary files

Objectives:

To compare the relative axis modification and canal concentricity after glide path preparation with 20/0.02 hand K-file (NITIFLEX^®) and 20/0.04 rotary file (HyFlex™ CM) with subsequent instrumentation with 1.5 mm self-adjusting file (SAF).

Materials and Methods:

One hundred and twenty ISO 15, 0.02 taper, Endo Training Blocks (Dentsply Maillefer, Ballaigues, Switzerland) were acquired and randomly divided into following two groups (n = 60): group 1, establishing glide path till 20/0.02 hand K-file (NITIFLEX^®) followed by instrumentation with 1.5 mm SAF; and Group 2, establishing glide path till 20/0.04 rotary file (HyFlex™ CM) followed by instrumentation with 1.5 mm SAF. Pre- and post-instrumentation digital images were processed with MATLAB R 2013 software to identify the central axis, and then superimposed using digital imaging software (Picasa 3.0 software, Google Inc., California, USA) taking five landmarks as reference points. Student's t-test for pairwise comparisons was applied with the level of significance set at 0.05.

Results:

Training blocks instrumented with 20/0.04 rotary file and SAF were associated less deviation in canal axis (at all the five marked points), representing better canal concentricity compared to those, in which glide path was established by 20/0.02 hand K-files followed by SAF instrumentation.

Conclusion:

Canal geometry is better maintained after SAF instrumentation with a prior glide path established with 20/0.04 rotary file.

Glide Path Enlargement of Mandibular Molar Canals by Using K-files, the ProGlider File, and G-Files: A Comparative Study of the Preparation Times

INTRODUCTION

The preparation of a glide path before the introduction of rotary nickel-titanium instruments is a standard adjunct to ensure increased safety during root canal preparation. The aim of this study was to compare the mean preparation time of manual instrumentation with K-files, G-Files, and the ProGlider instrument to prepare a glide path in curved root canals.

METHODS

The mesial canals of 90 mandibular molars (with curvature angles between 25° and 35°) were selected. The specimens were randomly divided into 3 groups with 30 canals each, and canal preparations were performed by an endodontist who used #10-15-20 stainless steel manual K-files (group KF), #10 stainless steel manual K-file followed by #12-17 G-File instruments (group GF), and #10 stainless steel manual K-file followed by #16 ProGlider instrument (group PG). The total time it took to prepare the glide paths was recorded with an electronic stopwatch. New instruments were used for each canal.

RESULTS

Glide path enlargement with the PG group (27.9 ± 8.6 seconds) and GF group (41.9 ± 20.1 seconds) was shown to be statistically significantly faster than stainless steel KF group (74.9 ± 24.1 seconds) by using analysis of variance (P < .05). There was no statistically significant difference observed between the mean preparation times of the PG and GF groups (P < .05).

CONCLUSIONS

Glide path preparation times with the rotary instrument groups were significantly faster than with stainless steel manual K-files.

Incidence of Apical Crack Initiation during Canal Preparation using Hand Stainless Steel (K-File) and Hand NiTi (Protaper) Files

Aim

To evaluate the incidence of apical crack initiation during canal preparation with stainless steel K-files and hand protaper files (in vitro study).

Materials and methods

Sixty extracted mandibular premo-lar teeth are randomly selected and embedded in an acrylic tube filled with autopolymerizing resin. A baseline image of the apical surface of each specimen was recorded under a digital microscope (80×). The cervical and middle thirds of all samples were flared with #2 and #1 Gates-Glidden (GG) drills, and a second image was recorded. The teeth were randomly divided into four groups of 15 teeth each according to the file type (hand K-file and hand-protaper) and working length (WL) (instrumented at WL and 1 mm less than WL). Final image after dye penetration and photomicrograph of the apical root surface were digitally recorded.

Results

Maximum numbers of cracks were observed with hand protaper files compared with hand K-file at the WL and 1 mm short of WL. Chi-square testing revealed a highly significant effect of WL on crack formation at WL and 1 mm short of WL (p = 0.000).

Conclusion

Minimum numbers of cracks at WL and 1 mm short of WL were observed with hand K-file and maximum with hand protaper files.

How to cite this article

Soni D, Raisingani D, Mathur R, Madan N, Visnoi S. Incidence of Apical Crack Initiation during Canal Preparation using Hand Stainless Steel (K-File) and Hand NiTi (Protaper) Files. Int J Clin Pediatr Dent 2016;9(4):303-307.

Radiographic technical quality of root canal treatment performed by a new rotary single-file system

AIM

The aim of the present study was to evaluate radiographically the technical quality of root canal filling performed by postgraduate students with a new single-file Nickel-Titanium System (F6 Skytaper Komet) in clinical practice.

METHODS

Records of 74 patients who had received endodontic treatment by postgraduate students at the School of Dentistry, Faculty of Medicine, University of Pavia in the period between September 2015 and April 2016 were collected and examined: the final sample consisted 114 teeth and 204 root canals. The quality of endodontic treatment was evaluated by examining the length of the filling in relation to the radiographic apex, the density of the obturation according to the presence of voids and the taper of root canal filling. Chi-squared analysis was used to determine statistically significant differences between the technical quality of root fillings according to tooth's type, position and curvature.

RESULTS

The results showed that 75,49%, 82,84% and 90,69% of root filled canals had adequate length, density and taper respectively.

CONCLUSIONS

Overall, the technical quality of root canal fillings performed by postgraduates students was acceptable in 60,78% of the cases.

The effect of sodium hypochlorite and resin cement systems on push-out bond strength of cemented fiber posts

Objective:

This study investigated the effect of different endodontic irrigant solutions and resin cement systems on the bond strength of cemented fiber posts.

Methods:

Sixty human single-rooted anterior teeth were sectioned transversely at 2 mm incisal to the cemento-enamel junction (CEJ). The roots were treated endodontically, and teeth were distributed into six groups: group A, includes 5.25%NaOCl irrigant with MultiCore Flow Core Build-Up material; group B, includes 5.25%NaOCl irrigant with RelyX-Unicem Self-Adhesive Universal Resin Cement; group C, includes 2.5% NaOCl irrigant with MultiCore Flow; group D, includes 2.5%NaOCl irrigant with RelyX-Unicem; group E, includes NaCl, irrigant with MultiCore Flow; and group F, includes NaCl irrigant with RelyX-Unicem. Universal tapered fiber posts (No. 3 RelyX Fiber Post) were cemented, and roots were sectioned into cervical and apical segments. Samples were then subjected to a push-out bond strength test and failure modes were examined.

Results:

The mean push-out bond strength for group D showed the highest mean value (20.07 MPa), while the lowest value was found in group A. There was a significant difference between groups with regard to the irrigants used (p<0.001), however, no significant difference was found between groups with regard to resin systems (p>0.05). The total mean push-out bond strength of the cervical segments was found to be significantly higher than the apical segments (p<0.001).

Conclusion:

The irrigant solution have a clear influence on the push-out bond strength of the fiber posts regardless of the cement used. Both adhesive resin systems showed similar bonding strength.

Radiological Evaluation of Penetration of the Irrigant according to Three Endodontic Irrigation Techniques

Introduction. This experimental study is to compare radiographs based on the penetration depth of the irrigant following three final irrigation techniques. Material and Method. A sample of sixty teeth with single roots were prepared with stainless steel K files followed by mechanized Ni-Ti files iRace® under irrigation with 2.5% sodium hypochlorite. Radiopaque solution was utilized to measure the penetration depth of the irrigant. Three irrigation techniques were performed during this study: (i) passive irrigation, (ii) manually activated irrigation, and (iii) passive irrigation with an endodontic needle CANAL CLEAN®. Radiographs were performed to measure the length of irrigant penetration in each technique. Results. In comparison, passive irrigation with a conventional syringe showed infiltration of the irrigant by an average of 0.682 ± 0.105, whereas the manually activated irrigation technique indicated an average of 0.876 ± 0.066 infiltration. Irrigation with an endodontic syringe showed an average infiltration of 0.910 ± 0.043. The results revealed highly significant difference between the three irrigation techniques (α = 5%). Conclusion. Adding manual activation to the irrigant improved the result by 20%. This study indicates that passive irrigation with an endodontic needle has proved to be the most effective irrigation technique of the canal system.

Antibacterial Efficacy of Calcium Hypochlorite with Vibringe Sonic Irrigation System on Enterococcus faecalis: An In Vitro Study

Aim. The purpose of this study was to compare the in vitro efficacy of calcium hypochlorite (Ca[OCl]₂) and sodium hypochlorite (NaOCl) associated with sonic (Vibringe) irrigation system in root canals which were contaminated with Enterococcus faecalis. Material and Methods. The root canals of 84 single-rooted premolars were enlarged up to a file 40, autoclaved, inoculated with Enterococcus faecalis, and incubated for 21 days. The samples were divided into 7 groups according to the irrigation protocol: G0: no treatment; G1: distilled water; G2: 2.5% NaOCl; G3: 2.5% Ca(OCl)₂; G4: distilled water with sonic activation; G5: 2.5% NaOCl with sonic activation; and G6: 2.5% Ca(OCl)₂ with sonic activation. Before and after decontamination procedures microbiological samples were collected and the colony-forming units were counted and the percentages of reduction were calculated. Results. Distilled water with syringe irrigation and sonic activation groups demonstrated poor antibacterial effect on Enterococcus faecalis compared to other experimental groups (p < 0.05). There was no statistically significant difference between syringe and sonic irrigation systems with Ca(OCl)₂ and NaOCl. Conclusion. The antimicrobial property of Ca(OCl)₂ has been investigated and compared with that of NaOCl. Both conventional syringe irrigation and sonic irrigation were found effective at removing E. faecalis from the root canal of extracted human teeth.

Does root canal treatment in necrotic pulp or retreatment cases with periapical lesions require anaesthesia? An in vivo clinical study

AIM

To examine whether local anaesthesia is required for treating teeth with necrotic pulps (TNP) and retreatment cases (RCs) associated with periapical lesions.

METHODOLOGY

Root canal treatment was performed in TNP and RCs without the administration of local anaesthesia. Patients were assured that if they experienced pain, local anaesthesia would be provided. Eighty canals, 40 TNP and 40 RCs, were included in the study. Two length measurements were performed: one using an electronic apex locator (EAL), which was defined as the electronic length (EL), and the second, the length at which the patient first reported that a size 15 file was touching the periapical tissues, which was defined as the periodontal length (PL). The difference between these two measurements (Δ = PL - EL) was the parameter studied. Statistical analysis was conducted using two-way anova and paired t-tests. Working length (WL) was defined in this study as being 0.5 mm short of the EL.

RESULTS

EL was shorter than PL in 96% of cases. The mean difference between measurements was 0.78 (±0.11) mm in the TNP group and 0.63 (±0.15) mm in the RC group; the difference was not significant. The distances between the WL and PL were thus 1.28 and 1.13 mm, respectively. In none of the 80 canals did the patient experience any pain, either during the measurements or during the instrumentation procedures.

CONCLUSIONS

When EALs are used, local anaesthesia may not be required for root canal treatment in teeth with necrotic pulps and retreatment cases associated with periapical lesions.

Effectiveness of Different Disinfection Protocols on the Reduction of Bacteria in Enterococcus faecalis Biofilm in Teeth with Large Root Canals

INTRODUCTION

This study compared the effectiveness of different disinfection protocols in reducing bacteria in an Enterococcus faecalis biofilm in teeth with large root canals.

METHODS

Fifty-five roots were prepared from human mandibular premolars with large single root canals, and 50 roots were infected with E. faecalis for 21 days. Four roots were observed using scanning electron microscopy to verify biofilm formation. The remaining specimens were assigned into 5 experimental groups and a sterile control group: mechanical instrumentation using files size 60-90 and 2.5% sodium hypochlorite (NaOCl) (MI-N), irrigation with 2.5% NaOCl (IR-N), irrigation with 2.5% NaOCl using intermittent passive ultrasonic irrigation (PUI-N), irrigation with normal saline, and no intervention (initial). After root canal disinfection, dentin specimens were collected for microbial analysis. Mean colony forming units were determined and compared between groups using 1-way analysis of variance.

RESULTS

The lowest number of intracanal bacteria (24.5 colony-forming units/mL) was recovered from the MI-N group followed by the PUI-N and IR-N groups. The irrigation with normal saline group did not show a significant reduction compared with the initial group. However, there were significant differences between groups (P < .01). The remaining bacteria in the PUI-N group was 4.5-fold lower compared with the IR-N group; however, it was 1862-fold higher compared with the MI-N group.

CONCLUSIONS

MI-N was the most effective method to disinfect large root canals. Although ultrasonic activation enhanced the efficacy of root canal irrigation, it could not substitute for mechanical instrumentation even in large root canals with unlimited irrigant access to the apical portion.

Comparative antimicrobial efficacy of herbal alternatives (Emblica officinalis, Psidium guajava), MTAD, and 2.5% sodium hypochlorite against Enterococcus faecalis: An in vitro study

AIM

The objective of this study was to evaluate the antimicrobial efficacy of herbal alternatives (Emblica officinalis, Psidium guajava), BioPure MTAD, and 2.5% sodium hypochlorite against Enterococcus faecalis.

MATERIALS AND METHOD

The testing of the antimicrobial efficacy of selected medicaments against E. faecalis was done by the agar disk-diffusion method. Whatman paper discs of 6 mm diameter were prepared and soaked with the test solution. These discs were then placed onto the previously seeded agar Petri plates. Later, these plates were incubated for 48 h at 37 °C under the appropriate gaseous conditions in a CO2 incubator. A zone of inhibition was recorded in millimeter for each plate and the results were analyzed statistically.

RESULT

MTAD was found to be superior in its antibacterial abilities against E. faecalis compared with the other irrigants used. All the other tested irrigants showed significant zone of inhibition.

CONCLUSIONS

BioPure MTAD offers better antibacterial efficacy than NaOCl. E. officinalis and P. guajava are effective antibacterial agents against E. faecalis and can be used to reduce root canal microflora and root canal failures.

Clinical Approach of High Technology Techniques for Control and Elimination of Endodontic Microbiota

The main goal in endodontic treatment is to eradicate or at least reduce intraradicular microbial population to levels that are more compatible with periapical lesions healing process. Since endodontic infections are polymicrobial in nature, intraradicular survival of endodontic microbiota and their pathogenic properties are influenced by a combination of their virulence factors. The purpose of this article is to review the endodontic microbiota and their respective virulence attributes, as well as perform a literature review of the effects of disinfection procedures in the treatment of endodontic infections to gain best practices. Conventional technique for root canal preparation includes mechanical debridement and application of antimicrobial irrigants. Recently, laser irradiation has been used to enhance the results of root canal treatment through its thermal effect. To reduce thermal side effects, laser activated irrigation (LAI) and photon induced photoacoustic streaming (PIPS) were introduced. Antimicrobial photodynamic therapy (aPDT) by photochemical reaction uses light at a specific wavelength to activate a nontoxic photosensitizer (PS) in the presence of oxygen to produce cytotoxic products. Different PSs are used in dentistry including methylene blue (MB), toluidine blue O (TBO), indocyanine green (ICG) and curcumin. Among different options, ICG could be the best choice due to its peak absorption at wavelength of 808 nm, which coincides with the commercial diode laser devices. Also, this wavelength has more penetration depth compared to other wavelengths used in aPDT.

The Effect of Preparation Size on Efficacy of Smear Layer Removal; A Scanning Electron Microscopic Study

INTRODUCTION

Enlargement of the root canal may potentially affect efficient smear layer (SL) removal. The aim of the present in vitro study was to compare SL removal following canal preparation with two different sizes/tapers by means of scanning electron microscopy (SEM).

METHODS AND MATERIALS

A total of 50 extracted human mandibular premolars were decoronated. The teeth were randomly divided into two experimental groups (n=20) and two negative control groups. In groups 1 and 2 the sizes of master apical file (MAF) were #25 and 40, respectively. Coronal part of the canals were flared with #2 Piezo drills in group 1 and sizes #2 to 6 in group 2. Finally FlexMaster NiTi rotary instruments were used to complete canal preparation (25/0.04 and 35/0.06 in groups 1 and 2, respectively). The irrigation protocol consisted of 10 mL of 17% ethylenediaminetetraacetic acid (EDTA) for 1 min followed by 10 mL of 5.25% NaOCl for 3 min. The patency of dentinal tubules was evaluated under SEM with Hülsmann scores. Data were analyzed with the Kruskal-Wallis and Mann-Whitney U tests.

RESULTS

The number of patent dentinal tubules in coronal third of the group 1 was significantly more than group 2 (P<0.001). However, this difference was not significant for the middle and apical segments. There was a significant difference in the number of patent dentinal tubules between coronal, middle and apical thirds (P<0.05).

CONCLUSION

Increasing the canal preparation size did not lead to better cleanliness of the canal walls and more efficient smear layer removal.

Bactericidal activity of propylene glycol, glycerine, polyethylene glycol 400, and polyethylene glycol 1000 against selected microorganisms

Aim:

The aim of the present study was to evaluate the bactericidal activity of propylene glycol, glycerine, polyethylene glycol 400 (PEG 400), and polyethylene glycol 1000 (PEG 1000) against selected microorganisms in vitro.

Materials and Methods:

Five vehicles, namely propylene glycol, glycerine, PEG 400, PEG 1000, and combination of propylene glycol with PEG 400, were tested for their bactericidal activity. The minimum bactericidal concentration was noted against four standard strains of organisms, i.e. Streptococcus mutans American Type Culture Collection (ATCC) 25175, Streptococcus mutans ATCC 12598, Enterococcus faecalis ATCC 35550, and Escherichia coli ATCC 25922, using broth dilution assay. Successful endodontic therapy depends upon thorough disinfection of root canals. In some refractory cases, routine endodontic therapy is not sufficient, so intracanal medicaments are used for proper disinfection of canals. Intracanal medicaments are dispensed with vehicles which aid in increased diffusion through the dentinal tubules and improve their efficacy. Among the various vehicles used, glycerine is easily available, whereas others like propylene glycol and polyethylene glycol have to be procured from appropriate sources. Also, these vehicles, being viscous, aid in sustained release of the medicaments and improve their handling properties. The most commonly used intracanal medicaments like calcium hydroxide are ineffective on many microorganisms, while most of the other medicaments like MTAD (Mixture of Tetracycline, an Acid, and a Detergent) and Triple Antibiotic Paste (TAP) consist of antibiotics which can lead to development of antibiotic resistance among microorganisms. Thus, in order to use safer and equally effective intracanal medicaments, newer alternatives like chlorhexidine gluconate, ozonized water, etc., are being explored. Similarly, the five vehicles mentioned above are being tested for their antimicrobial activity in this study.

Results:

All vehicles exhibited bactericidal activity at 100% concentration.

Conclusion:

Propylene glycol was effective against three organisms namely S. mutans E. faecalis and E. coli and its bactericidal activity was at 50%, 25% and 50% respectively. PEG 1000 was effective against S. mutans and E. coli at 25%. Hence propylene glycol was effective on more number of organisms of which E. faecalis is a known resistant species. PEG 1000 was bactericidal at a lower concentration but was effective on two organisms only.

Impact of root canal preparation size and taper on coronal-apical micro-leakage using glucose penetration method

OBJECTIVES

The purpose of this in vitro study was to assess the effect of root canal preparation size and taper on the amounts of glucose penetration.

MATERIAL AND METHODS

For conducting this experimental study, eighty mandibular premolars with single straight canals were divided randomly into 2 experimental groups of 30 samples each and 2 control groups. Using K-files and the balance force technique, canals in group 1 were prepared apically to size 25 and coronally to size 2 Peesoreamer. Group 2 were instrumented apically and coronally to size 40 and size 6 Peesoreamer, respectively. Rotary instrumentation was accomplished in group 1; using size 25 and .04 tapered and in group 2, size 35 and .06 tapered Flex Master files. Canals were then obturated by lateral compaction of cold gutta-percha. Glucose penetration through root canal fillings was measured at 1, 8, 15, 22 and 30 days. Data were recorded as mmol/L and statistically analyzed with Mann-Whitney U test (P value=. 05).

RESULTS

In comparison to group 1, group 2 showed significant glucose leakage during the experimental period (P value < .0001). Also, in each experimental group, the amount of micro-leakage was significantly increased at the end of the study.

CONCLUSIONS

Under the condition of this study, the amounts of micro-leakage through root canal fillings are directly related to the size and taper of root canal preparation and reducing the preparation size may lead to less micro-leakage. Key words:Dental leakage, root canal preparation, endodontics.

Modifications in Canal Anatomy of Curved Canals of Mandibular First Molars by two Glide Path Instruments using CBCT

BACKGROUND

The creation of glide path reduces the risk of instrument breakage. Glide path is created before using NiTi rotary instrumentation Aim: This study compared the changes in the root canal anatomy after creation of glide path using Path Files (PF) and V Glide Path 2 (VGP2) using Cone Beam Computed Tomography (CBCT).

MATERIALS AND METHODS

Hundred extracted mandibular first molars with curved mesial roots, curvature angles ranging within 20-30 degrees were assigned into two groups (n = 50 each). Glide path was prepared using PF (Group I) and VGP2 (Group II). CBCT images were obtained before and after instrumentation. The technical outcomes were compared at 0, 1, 2, 3, 5 and 7mm intervals. The data was analyzed using t-test and Chi-square test.

RESULT

There was a statistical difference between the root canal curvatures and working time between the two groups (p < 0.05). Canals transported towards the distal side in Group II but there was a slight mesial transportation in Group I at 0mm. Group I exhibited a better centric ability except at 1mm interval (p > 0.05). The changes in the volume were statistically significant only at 2mm interval (p < 0.05). The difference in the cross sectional area was not statistically significant at any interval (p > 0.05).

CONCLUSION

Within the limits of this study the rotary Nickel Titanium Path Files appeared to be suitable instruments for safe and easy creation of glide path.

Management of sodium hypochlorite extrusion beyond the root apex during root canal treatment: a case report

Sodium hypochlorite (NaOCl) is most commonly used as an irrigating solution in endodontic practice. This paper describes an incident of sodium hypochlorite extrusion past the apex (SHEPA) of the UR3. Management of the condition resulted in hospitalisation of the patient, and intravenous antibiotic and steroid therapy. This case report details the measures that can be employed to reduce the risk of SHEPA and management of its potentially serious complications. The reader should understand the various measures that can be adopted to reduce extrusion of endodontic irrigants beyond the root apex and management following SHEPA.

Comparison of the shaping ability of GT® Series X, Twisted Files and AlphaKite rotary nickel-titanium systems in simulated canals

Background

Efforts to improve the performance of rotary NiTi instruments by enhancing the properties of NiTi alloy, or their manufacturing processes rather than changes in instrument geometries have been reported. The aim of this study was to compare in-vitro the shaping ability of three different rotary nickel-titanium instruments produced by different manufacturing methods.

Methods

Thirty simulated root canals with a curvature of 35˚ in resin blocks were prepared with three different rotary NiTi systems: AK- AlphaKite (Gebr. Brasseler, Germany), GTX- GT^® Series X (Dentsply, Germany) and TF- Twisted Files (SybronEndo, USA).

The canals were prepared according to the manufacturers’ instructions. Pre- and post-instrumentation images were recorded and assessment of canal curvature modifications was carried out with an image analysis program (GSA, Germany).

The preparation time and incidence of procedural errors were recorded. Instruments were evaluated under a microscope with 15 × magnifications (Carl Zeiss OPMI Pro Ergo, Germany) for signs of deformation. The Data were statistically analyzed using SPSS (Wilcoxon and Mann–Whitney U-tests, at a confidence interval of 95%).

Results

Less canal transportation was produced by TF apically, although the difference among the groups was not statistically significant. GTX removed the greatest amount of resin from the middle and coronal parts of the canal and the difference among the groups was statistically significant (p < 0.05). The shortest preparation time was registered with TF (444 s) and the longest with GTX (714 s), the difference among the groups was statistically significant (p < 0.05). During the preparation of the canals no instrument fractured. Eleven instruments of TF and one of AK were deformed.

Conclusion

Under the conditions of this study, all rotary NiTi instruments maintained the working length and prepared a well-shaped root canal. The least canal transportation was produced by AK. GTX displayed the greatest cutting efficiency. TF prepared the canals faster than the other two systems.