Differences in disinfection protocols for root canal treatments between general dentists and endodontists: A Web-based survey

Global survey of endodontic practice and adoption of newer technologies

AIM

To investigate current endodontic practices, adoption of technologies and continuing education attendance within specialist endodontic practice globally and to identify geographic trends.

METHODOLOGY

A web-based survey of endodontic association members in Australia, Britain, Canada, Italy, New Zealand and the USA on routine treatment preferences, armamentarium and education attendance was conducted. Chi-squared, independent sample t-tests, Cochran's Q test and McNemar's test were performed.

RESULTS

The survey was completed by 543 endodontists or endodontic post-graduate students. Almost all respondents used the dental operating microscope (DOM, 91.3%), engine-driven nickel-titanium instruments (NiTi, 97.6%), electronic apex locators (EAL, 93.0%), cone-beam computed tomography (CBCT, 91.2%) and calcium silicate-based materials (CSBMs, 93.7%). Dental dam was always used by 99.1%. Over half used irrigation adjuncts (81.8%), warm vertical compaction (74.6%) and heat-treated NiTi (60.2%). Geographic comparison between AP (Asia-Pacific, n = 78), AM (Americas, n = 402) and EM (Europe and Middle East, n = 63) was performed. AM and EM preferred single-visit treatment more (p < .001) and used higher sodium hypochlorite concentrations than AP. AM had more access to CBCT in the workplace (86.6%) than AP (65.4%, p < .001) and used CBCT for routine preoperative assessment (39.6%) more than EM (7.3%, p < .001). Almost all of EM used irrigation adjuncts (95.2%), more than AM (78.1%, p = .001). AP used steroid/antibiotic medicaments most (p < .001) and had the highest attendance at continuing education programmes.

CONCLUSION

Several endodontic-specific armamentaria have reached almost complete adoption within global specialist endodontic practice, whilst the continued uptake of newer technologies should be followed over time. Some practising philosophies varied significantly across different geographic regions.

The effect of a preparation containing glycocholic acid on the biocidal efficacy of sodium hypochlorite in a biofilm laboratory model

This study assessed the antimicrobial effect of sodium hypochlorite (NaOCl) mixtures combined with Keratobacter (KB) using an engineered biofilm root canal model. Clinical and reagent grade NaOCl were mixed with KB (9:1-vol/vol) to assess pH values over 1 min to select the ideal solution with a pH just below the pKa of hypochlorous acid. The samples were randomly divided into five groups: 1% and 4% NaOCl reagents, a mixture of NaOCl:KB using 1% and 4% NaOCl reagents and distilled water. Outcome measures were colony-forming units (CFUs/mL) and positive/negative cultures. No significant differences were observed in the pairwise comparisons between 1%, 4% NaOCl and 4% NaOCl+KB for the outcome CFUs/mL. Only 4% NaOCl presented with negative cultures in all samples, whereas 1% NaOCl and 4% NaOCl+KB had similar results (54% vs. 40%). The addition of KB has a limited effect on the antimicrobial efficacy of 4% NaOCl in this laboratory model.

Effectiveness of root canal irrigation and dressing for the treatment of apical periodontitis: A systematic review and meta-analysis of clinical trials

BACKGROUND

Sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA) and/or calcium hydroxide (Ca(OH)2 ) are commonly used during root canal treatment. Evaluation of their effectiveness regarding clinical and patient-related outcomes requires further understanding.

OBJECTIVES

To assess the effectiveness of root canal irrigation and dressing for the treatment of teeth with apical periodontitis (AP).

METHODS

A search was conducted in the PubMed-MEDLINE, Scopus, EMBASE, Google scholar databases and available repositories, followed by hand searches, until July 2021. Eligibility criteria followed the a priori formulated Population, Intervention, Comparator, Outcomes, Timing, and Study design (PICOTS) framework. Clinical studies restricted to English language were included. The revised Cochrane risk-of-bias tool for randomised trials (RoB 2) was used to assess the quality of included studies. Meta-analyses were performed using the fixed-effect model to obtain Risk Ratio (RR) and 95% Confidence Interval (CI), with sensitivity analysis. Overall quality of evidence of meta-analyses was assessed through the Grading of Recommendations Assessment, Development, and Evaluation tool.

RESULTS

The search identified 1357 records of which six fulfilled the inclusion criteria, providing data for 'irrigation' from 212 teeth and for 'dressings' from 438 teeth. Two studies reported no significant difference regarding the outcome 'pain at 7 days' using 2% chlorhexidine vs. 5.25% NaOCl and EDTA or after using different concentrations of NaOCl (1% vs. 5%). No significant difference was detected between different NaOCl concentrations regarding the reduction of AP. A meta-analysis was possible for the comparison of single-visit (SV) versus multiple-visits including the use of Ca(OH)2 demonstrating a significant effect in favour of SV (RR: 1.10; 95% CI: 1.03-1.19; p = .007; I2  = 0). RoB of included studies was moderate to low.

DISCUSSION

The use of Ca(OH)2 for the treatment of AP may not be beneficial. There is scarce or no evidence fulfilling the proposed PICOTS regarding irrigants and dressings.

CONCLUSIONS

There is moderate certainty that SV treatment is associated with better radiographic evidence of normal periodontal ligament space (strict criteria) compared with the use of Ca(OH)2. Reduction of AP is comparable after irrigation with 1% and 5% NaOCl, whereas postoperative pain at 7 days for the irrigants assessed is similar.

REGISTRATION

PROSPERO database CRD42021260271.

Centric versus eccentric engine-driven endodontic instrument design for microbial load reduction-A systematic review and meta-analysis of randomised clinical trials

This systematic review assessed the clinical influence of centric and eccentric engine-driven instrument design for reduction in microbial load in infected root canal system. The literature search was conducted in electronic databases (PubMed, Cochrane Library, Scopus, Lilacs and Google Scholar) and grey literature till June 2022. The search strategy followed the PRISMA 2020 guidelines. Qualitative and quantitative synthesis was conducted based on the guidelines of the Cochrane Handbook. The risk of bias was assessed using the revised Cochrane criteria and quality of evidence was conducted using the Grading of Recommendation Assessment, Development and Evaluation tool. Out of 28 papers, only five papers met the inclusion criteria of this review. Studies showed reduction in microbial load after instrumentation using centric or eccentric instruments with no statistically significant difference in the meta-analysis. In conclusion, there is low-grade evidence suggesting that microbial reduction is similar using centric and eccentric instruments.

The efficacy of a novel SWEEPS laser-activated irrigation compared to ultrasonic activation in the removal of pulp tissue from an isthmus area in the apical third of the root canal

This study aimed to evaluate the efficacy of Shock Wave Enhanced Emission Photoacoustic Streaming (SWEEPS) in the removal of remaining pulp tissue from the root canal isthmus area in lower molars and compare it with ultrasonically activated irrigation (UAI) and conventional needle irrigation (NI). Forty-one lower molars with isthmuses between mesial canals were included in the study. The teeth were randomly distributed into experimental groups (n = 12/each) based on the final irrigation protocol (SWEEPS, UAI, or NI) and a control group (C) (n = 5). The traditional access cavity of the mesial part of each tooth was made in all samples. The mesial root canals in the experimental groups were instrumented with a Wave One Gold Primary (25/.07) file using 3% sodium hypochlorite (NaOCl) while the distal canal served as a control for the presence of pulp tissue. No treatment was performed in the C group. Sections from the isthmus region were processed for histopathology to measure the remaining pulp tissue (RPT). The results were analyzed using analysis of variance and the Kruskal-Wallis test (α = 0.05). There were no significant differences in the relative surface area of root canals and isthmus among the groups (p > 0.05). Samples in the SWEEPS group had significantly less RPT than UAI, NI, and C (p = 0.003, 0.014, 0.003, respectively). There were no significant differences between the UAI and NI (p = 0.583). SWEEPS was the most efficient in debridement of the root canal isthmus area. UAI and NI showed similar but lower efficiency.

Knowledge, Attitude, and Practice towards Chelating Agents in Endodontic Treatment among Dental Practitioners

The use of chelating agents (CAs) in the endodontic irrigation protocol is required to dissolve the inorganic components of the smear layer. We aimed to assess the knowledge, attitude, and practice of dental professionals regarding the use of CAs during root canal treatment. A cross-sectional anonymous online survey was conducted among specialized endodontists and general dentists who routinely perform endodontic treatment and work in government-funded or private clinics in Moscow. The 8 min survey consisted of four parts: basic demographic data, knowledge (five items), attitude (four items), and practice (five items). We collected 376 completed questionnaires; a majority of the respondents were general dentists (87.5%) and worked in private clinics (77.4%). Most respondents (83.5%) showed a fair knowledge of the CAs used in endodontics, while 16.5% showed a poor knowledge of the topic. Small yet significant differences were found between endodontists and general practitioners and between dentists employed by private and government-funded clinics. A majority of dental practitioners (83%) demonstrated a positive attitude towards the use of CAs in endodontic treatment, and there were no differences among the study subgroups. Almost a third of the respondents always used chelating solutions during endodontic treatment, while 17% of the respondents did not use them at all. There were significant differences in this parameter between dentists working in private and government-funded clinics. Practice significantly correlated with attitude towards chelating agents and with knowledge of the topic. In conclusion, dental practitioners demonstrated a fair knowledge of CAs. Despite a positive attitude, 71% of the respondents did not use CAs for all endodontic patients.

Effect of preparation size on the removal of accumulated hard-tissue debris from the mesial root canal system of mandibular molars using SWEEPS technology

OBJECTIVES

This study assessed the influence of preparation size on the efficacy of shock wave-enhanced emission photoacoustic streaming (SWEEPS) and conventional irrigation (CI) on removal of accumulated hard tissue debris (AHTD) from isthmus-containing mandibular molars using micro-computed tomographic analysis.

MATERIALS AND METHODS

Sixty extracted mandibular molars with two mesial canals connected by an isthmus were selected. Canals were shaped with Mtwo instruments (VDW, Munich, Germany) up to sizes 25/.06, 40/.04 or 40/.06 (n = 20), and specimens were distributed into 2 final irrigation groups (n = 10): SWEEPS and CI. Roots were scanned at a resolution of 10.5 µm before and after preparation and final irrigation. Data sets were co-registered, and the percentage reduction of AHTD calculated for each specimen was statistically compared using analysis of variance with a of 5% significance level.

RESULTS

The preparation size did not significantly influence the percentage reduction of AHTD (p < 0.05), whereas the final irrigation technique had a significant effect on debris removal (p < 0.05). A significant reduction of AHTD was achieved after final irrigation in all groups (p < 0.05); however, SWEEPS was associated with a significantly greater percentage reduction of debris than CI (p < 0.05). None of the specimens presented a completely clean isthmus.

CONCLUSIONS

Removal of AHTD was not significantly affected by the preparation size. SWEEPS was associated with significantly less debris than CI.

CLINICAL RELEVANCE

SWEEPS performed significantly better than CI regarding the removal of AHTD from isthmus-containing mandibular molars irrespective of the preparation size.

Present status and future directions - irrigants and irrigation methods

Irrigation is considered the primary means of cleaning and disinfection of the root canal system. The purpose of this review was to set the framework for the obstacles that irrigation needs to overcome, to critically appraise currently used irrigants and irrigation methods, to highlight knowledge gaps and methodological limitations in the available studies and to provide directions for future developments. Organization of bacteria in biofilms located in anatomic intricacies of the root canal system and the difficulty to eliminate them is the main challenge for irrigants. Sodium hypochlorite remains the primary irrigant of choice, but it needs to be supplemented by a chelator. Delivery of the irrigants using a syringe and needle and activation by an ultrasonic file are the most popular irrigation methods. There is no evidence that any adjunct irrigation method, including ultrasonic activation, can improve the long‐term outcome of root canal treatment beyond what can be achieved by instrumentation and syringe irrigation. It is necessary to redefine the research priorities in this field and investigate in greater depth the penetration of the irrigants, their effect on the biofilm and the long‐term treatment outcome. New studies must also focus on clinically relevant comparisons, avoid methodological flaws and have sufficiently large sample sizes to reach reliable conclusions. Future multidisciplinary efforts combining the knowledge from basic sciences such as Chemistry, Microbiology and Fluid Dynamics may lead to more effective antimicrobials and improved activation methods to bring them closer to the residual biofilm in the root canal system.

Effect of Various Irrigant Activation Methods and Its Penetration in the Apical Third of Root Canal-In Vitro Study

OBJECTIVE

 The objective of this study was to evaluate the irrigant penetration using iohexol dye with four irrigation techniques.

METHODOLOGY

 Single-rooted premolars were recently extracted and preserved in physiological saline solution. All the samples were standardized to 16 mm. Standard endodontic access was prepared using endoaccess bur (Dentsply Maillefer, Switzerland). The initial patency was established using #10 k file (Mani, Utsunomiya, Tochigi, Japan) to the working length. The cleaning and shaping were performed using the file system ProFit S3 in the following sequence: P0 (orifice enlarger), PF1 (yellow), PF2 (red) #25, and PF3 (blue) #30. The samples were randomly allocated in concealed opaque envelopes into four groups. This was performed by a trained dentist. Fifteen samples were allocated to one group. The groups were divided as follows: Group A-conventional needle (CN), Group B-side-vented needle (SVN), Group C-manual dynamic agitation (MDA), and Group D-EndoActivator (EA). The radiopaque dye irrigant agitation/activation was performed by one operator to prevent operator bias. Following irrigation using the different techniques, digital radiographs were taken, and the measurement was taken from the apical foramen to the point where the dye had penetrated apically for each tooth and the data were entered into an Excel sheet for all the four groups.

RESULTS

 Comparing the four groups, there was a statistically significant difference among the four groups (p < 0.05), thus, favoring the alternate hypothesis. EA had resulted in better penetration of the irrigant compared with the other three groups (p < 0.05).

CONCLUSION

 It was evident that irrigant penetration was best achieved with the use of an EA followed by MDA, SVNs, and then the CN when the preparation was done till size 30 (PF3 #30) using ProFit S3 rotary file system.

Ex Vivo Effect of Novel Lipophosphonoxins on Root Canal Biofilm Produced by Enterococcus faecalis: Pilot Study

(1) Background: The root canal system has complex anatomical and histological features that make it impossible to completely remove all bacteria by mechanical means only; they must be supplemented with disinfectant irrigation. Current disinfectants are unable to eliminate certain microorganisms that persist in the root canal, resulting in treatment failure. At the Institute of Organic Chemistry and Biochemistry, Prague, novel substances with the bactericidal effect, termed lipophosphonoxins (LPPOs), have been discovered. The aim of this pilot study was to investigate the ex vivo effects of second- and third-generation LPPOs on Enterococcus faecalis and compare them with 5% sodium hypochlorite (NaOCl), 0.12% chlorhexidine digluconate, and 17% ethylenediaminetetraacetic acid (EDTA). (2) Methods: The root canal’s dentin was used as a carrier for biofilm formation in the extracted human mature mandibular premolars. The samples were filled with cultivation broth and 0.25% glucose with tested solutions. In control samples, only fresh cultivation broth (negative control) and cultivation broth with bacterial suspension (growth control) were used. Each sample was inoculated with E. faecalis CCM4224 except for the negative control, and cultivation was performed. To determine the number of planktonic cells, the sample content was inoculated on blood agar. To evaluate biofilm formation inhibition, samples were placed in tubes with BHI. (3) Results: LPPOs exhibited a reduction in biofilm growth and bacteria comparable to NaOCl, and they were superior to other tested disinfectants. (4) Conclusions: The study results suggest the effect of lipophosphonoxins on E. faecalis CCM 4224 reduces planktonic bacterial cells and inhibits formation of biofilm in root canal samples.

Etidronic acid and ethylenediaminetetraacetic acid associated with sodium hypochlorite have limited effect on the compressive fracture resistance of roots ex vivo

Aims:

To assess the effect of etidronic acid (EA) mixed with sodium hypochlorite (NaOCl) and two ethylenediaminetetraacetic acid-containing preparations (EDTA and SmearClear) alternated with NaOCl, as a final rinse, on root fracture resistance to a compressive force.

Materials and Methods:

Seventy-two premolar roots were randomly allocated to the following groups according to the irrigant solutions. For the EA group, 9% EA + 2.5% NaOCl were used throughout the assays (n = 21). The remaining groups received 2.5% NaOCl during and immediately after chemo-mechanical instrumentation. Intermediately, the roots received 17% EDTA (n = 19), or SmearClear (n = 16), or no irrigation (control) (n = 16) plus a final rinse with 2.5% NaOCl. The specimens were subjected to a vertical compressive force loaded at a crosshead speed of 0.02 mm/s parallel to the long axis of the root until fracture occurred. The results were compared statistically using the one-way analysis of variance for intergroup comparisons.

Results:

The negative control presented with the highest values, whereas the SmearClear presented with the lowest values, though no significant differences were found when comparing the different groups (P = 0.82).

Conclusions:

The use of EA + NaOCl or two EDTA formulations in association with NaOCl does not affect the fracture resistance of previously chemo-mechanically prepared roots.

The effect of a preparation containing glycocholic acid and/or agitation on the tissue dissolution ability of sodium hypochlorite

This study assessed the porcine palatal mucosa dissolution, from artificial grooves, by a final rinse of sodium hypochlorite (NaOCl) solely or mixed with Keratobacter ((KB); or agitation) passive ultrasonic irrigation (PUI) or sonic activation (SA). Soft-tissue samples (n = 123) were weighed and placed inside root canal grooves in central maxillary incisors. The specimens were randomly divided into six test groups (n = 20): NaOCl 3% with or without KB and the irrigation dynamics: positive pressure (PP), SA or PUI. An EDTA intermediate rinse was included. Soft-tissue weights were measured subsequently. The NaOCl + KB_PUI group showed the highest mean weight reduction, whilst the NaOCl_PP group recorded the lowest. NaOCl + KB subgroups were associated with hastened reduction compared with NaOCl subgroups. NaOCl_PP presented with significantly lower weight reduction when compared with the remaining experimental groups. The addition of KB to NaOCl or its agitation enhances tissue dissolution ex vivo. The agitation of KB-containing mixtures offers no further benefits.