European Endodontic Journal最新文献

Objective: The aim of this study was to evaluate the influence of cone-beam computed tomography (CBCT) resolution, 3D printing resolution, and drilling depth on drilling accuracy in guided endodontic access.

Methods: Fifty-six printed canines were designed, fabricated, and mounted in maxillary arch models. Preoperative CBCT and 3D surface scan were matched and used to design a surgical guide with different planning parameters: 1) reference (high-resolution CBCT (80 µm) and 3D printing (50 µm), shallow drilling (14 mm)), 2) low-resolution CBCT (120 µm), 3) low-resolution 3D printing (100 µm) and 4) deep drilling (high-resolution CBCT (80 µm) and 3D printing (50 µm), deep drilling (21 mm)). Guided access into the printed canines was performed in a simulated clinical setting. A postoperative CBCT was matched with the planning data in order to determine the angular and linear (total, mesiodistal, buccolingual and depth) deviation between the planned and performed cavities. Mann-Whitney test was used to analyse differences between the reference group and each test group.

Results: Angular, total linear and buccolingual deviations were significantly higher in the low-resolution CBCT group than in the reference group (median: 3.10° and 2.0° (p<0.01), 1.41 mm and 1.06 mm (p<0.05) and 0.77 mm and 0.41 mm (p<0.05), respectively). Depth deviation was significantly higher in the low-resolution 3D printing group than in the reference group (median: 0.90 mm and 0.45 mm (p<0.01), respectively). No other significant differences between the groups were noted (p>0.05).

Conclusion: Higher CBCT resolution resulted in lower angular and total linear deviation during guided endodontic access. Higher 3D printing resolution yielded lower vertical linear deviation. (EEJ-2024-05-086).

Objective: High-intensity focused ultrasound (HIFU) has demonstrated significant efficacy in eradicating bacteria from substrates emerging as a promising solution for root canal disinfection. This in-vitro study investigated the effects of HIFU on reducing intracanal bacteria and its impact on the chemical and mechanical properties of root dentine. It also aimed to demonstrate acoustic wave penetration and distribution within the root canal system (RCS) and characterize the associated temperature changes.

Methods: Eighty-two extracted premolar teeth with single canals, infected with Enterococcus faecalis (E. faecalis) and cultured for two weeks, were randomly assigned to four groups: negative control, 4% sodium hypochlorite (NaOCl), 60 s HIFU, and 120 s HIFU (operated at 250 kHz/20W). Post-treatment, biofilm samples were collected from the root canals to assess viable bacterial cells using colony-forming unit (CFU) and 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assays. The root canal surfaces were subsequently examined using scanning electron microscopy, confocal laser scanning microscopy (CLSM), microhardness, and Raman spectroscopy. Acoustic wave penetration, distribution, and temperature changes within the RCS were examined using CLSM and thermal camera.

Results: HIFU at 60 s and 120 s consistently demonstrated superior anti-bacterial efficacy against E. faecalis biofilms compared to 4% NaOCl. MTT and CFU assays revealed a significant reduction in biofilm viability, particularly at 120 s of HIFU exposure (p<0.05). CLSM and SEM analyses demonstrated enhanced penetration and detachment of biofilms, as well as improved smear layer removal and preservation of dentinal tubules, especially at 120 s of HIFU exposure. HIFU treatment did not adversely affect the amide/mineral content of root dentine or its surface microhardness. Additionally, HIFU enhanced acoustic wave propagation and resulted in a controlled increase in temperature within the root canal over time.

Conclusion: This minimally invasive approach shows promise for removing bacterial biofilms in the RCS, positioning HIFU as a valuable adjunctive treatment for enhancing root canal disinfection. (EEJ-2024-08-123).

Objective: This study aimed to evaluate the effectiveness of a 3D printed training kit for the preparation of endodontic access cavities in calcified teeth.

Methods: The root canal system of a micro-CT scanned premolar was digitally processed to create an endodontic training kit containing 10 teeth with ten different progressive degrees of pulp canal calcification. A tooth variant with a medium calcification degree (5/10) was printed in three copies using opaque resin. Additionally, a set of 10 transparent training teeth with red-colored pulp was produced using PolyJet 3D printing technology, which was used to train the access cavity preparation in a controlled manner due to the transparency of the teeth. Undergraduate students (n=27) and dentists (n=10) each prepared a total of 13 (one pre-training, two post-training) access cavities. Substance loss was quantified by CBCT, and user satisfaction was evaluated by questionnaire. Paired t-tests were used to compare the means for substance loss and procedure time for pre- and post-training conditions. Unpaired t-tests were used to compare differences between students and dentists. The level of significance was set at α=0.05.

Results: Mean substance loss before and after training decreased for both students (71.4 versus 54.68 mm3; p=0.069) and dentists (67.3 versus 51.1 mm3; p=0.633), but the difference was not statistically significant. The average preparation time decreased with training for students (420 versus 275 seconds; p=0.100) and dentists (336 versus 158 seconds; p=0.054), but not significantly. Root perforation rates also decreased (students: 6/27 versus 4/27; dentists: 1/10 versus 0/10). Participants rated the training model as very realistic and useful, despite the difference in material texture.

Conclusion: The proposed 3D printed training kit appears to be a suitable tool for undergraduate dental students, which could expand their opportunities to practice the preparation of endodontic access cavities in calcified teeth. (EEJ-2024-06-091).

Objective: Sodium hypochlorite is a common irrigant in endodontics, used to eliminate microorganisms and dissolve pulpal tissue. However, adjunctive chelating agents, while aiding in smear layer removal, can reduce dentinal wall microhardness, affecting dentin permeability, solubility, and the sealing ability of root canal sealers. This study aims to evaluate the impact of newer chelating agents-Silver Citrate, Chitosan, HEBP, and EDTA-on the mineral composition of root canal dentin using energy-dispersive X-ray Spectroscopy (EDXS).

Methods: The root canals of 120 freshly extracted human mandibular premolars with single straight canals and intact, mature apices were prepared following standard endodontic procedures using Rotary Pro Taper nickel-titanium files. Final irrigation was conducted with 5 mL of the respective chelating solution. Changes in the mineral composition of the root canal dentin were analyzed using EDXS. Descriptive statistics were presented as means and standard deviations. The impact of chelating solutions on the mineral content of root canal dentin at the cervical, middle, and apical thirds was compared between groups using One-Way ANOVA followed by a post hoc Bonferroni test.

Results: The highest mean concentrations of minerals such as Mg, Ca, and P at both the coronal and apical levels (p<0.05), along with the Ca/P ratio in the coronal third, were observed with distilled water, followed by HEBP, Chitosan, EDTA, and Silver Citrate, which showed the lowest values. In the middle third, the concentrations of Ca and P, as well as the Ca/P ratio in the apical and middle thirds, followed the sequence: Distilled Water>EDTA>HEBP>Chitosan>Silver Citrate. The difference in the levels of all minerals was statistically significant (p<0.05) at the coronal, middle and apical third levels.

Conclusion: Among the tested solutions, 9% HEBP caused the least alteration in the mineral content of root canal dentin when compared to 0.2% Chitosan, 17% EDTA, and Silver Citrate. This suggests that HEBP may be a preferable choice in endodontic procedures where minimal alteration of dentin mineral content is desired. (EEJ-2024-08-124).

Objective: This study aimed to investigate the effects of D-galactose (D-gal) on cellular senescence induction, cell proliferation, mineralization production, and odontogenic gene expression of isolated human dental pulp cells (HDPCs).

Methods: Isolated HDPCs were cultured and assigned to four groups: control, 1 g/L D-gal, 10 g/L D-gal, and 10 g/L D-gal with Biodentine (BD). Cell proliferation was evaluated at 24, 48, and 72 hours using Alamar Blue® assay. To evaluate cellular senescence at 48 hours, senescence-associated beta-galactosidase (SA-β-gal) activity and senescence-related genes (p16 and p21) were assessed with SA-β-gal staining assay and quantitative reverse-transcription polymerase chain reaction (qRT-PCR), respectively. To examine the mineralization potential under differentiating conditions, quantitative staining with Alizarin Red S and mineralization-related gene expression (dentine sialophosphoprotein, DSPP) were investigated at 14 days. One-way ANOVA was used for statistical analysis. The statistical significance level was set at 0.05.

Results: 1 g/L D-gal and 10 g/L of D-gal significantly decreased cell proliferation at 72 hours compared to the control group (p<0.05). SA-β-gal-positive cells were significantly more prevalent in both D-gal-treated groups than in the control group (p<0.05). The expressions of genes p16 and p21 were markedly increased in cells treated with 10 g/L D-gal compared to the control group (p<0.05). The addition of BD did not promote cell proliferation but significantly improved cellular senescence by reducing SA-β-gal activity, p16, and p21 expression (p<0.05) compared to the group without BD. For mineralization potential, the amount of mineralization was similar among groups under differentiating conditions. The reduction of DSPP gene expression was obvious only in the 10 g/L D-gal group (p<0.05). The addition of BD did not show a significant effect on mineralization.

Conclusion: Ten g/L of D-gal can effectively induce aging phenotypes and reduce DSPP gene expression in HDPCs. Co-incubation with BD extract reduced the expression of these aging phenotypes. Mineralization production was not altered in the presence of D-gal. The data support the development of in vitro model for aging dental pulp. (EEJ-2024-07-108).

Blood clot, platelet-rich fibrin, and plasma-rich plasma are the three most commonly used scaffolds in regenerative endodontic therapy. The current study aimed to evaluate the clinical outcomes of plasma-rich plasma (PRP) and platelet-rich fibrin (PRF) scaffolds and blood clot (BC) in regenerative endodontic therapy. For this systematic review and meta-analysis, international databases such as MEDLINE (PubMed and Ovid), Web of Science, and Scopus were searched between January 2013 and November 2023 using keywords relevant to the study objectives. Randomized controlled trials published in English that investigated the effects of BC, PRF, and PRP interventions compared to each other on permanent teeth with a six-month follow-up period were included in the study. The risk of bias was assessed using the Cochrane tool for randomized trials. Data were analyzed using STATA/MP software, employing odds ratios with fixed and random effects models in the meta-analysis. Fourteen randomized clinical trials involving 430 participants were reviewed. The present study did not reveal any statistically significant differences between BC and PRP regarding apical radiolucency healing (OR: -1.30, 95% CI; -2.68, 0.08; p=0.07, I2=0%, p=0.91) and apical closure (OR: -0.29, 95% CI; -1.07, 0.49; p=0.47, I2=32.63%, p=0.20). However, root-length increase in BC was greater compared to PRP (OR: 3.18, 95% CI; 2.78, 3.57; p<0.01) and PRF (OR: 1.75, 95% CI; 1.38, 2.13; p<0.01). The risk of bias was low for all studies, based on the Cochrane tool. BC is the preferred primary scaffold in regenerative endodontic therapy, while PRP and PRF are recommended for cases of severe canal bleeding. (EEJ-2024-05-079).

Objective: Biomechanical root canal preparation involves both mechanical instrumentation and endodontic irrigation, aiming to reduce bacterial levels to promote periradicular healing. However, complete removal of biofilm and debris, especially in complex canal morphologies, remains difficult. This study aimed to evaluate, through microcomputed tomography (micro-CT), the use of the XP-Endo Finisher and Tornado Disinfection Kit (TDK) systems during the final agitation of the irrigating solution for the final debridement of oval-shaped canals of lower incisors.

Methods: Thirty-nine extracted human mandibular incisors were instrumented up to size #25/.05 and divided into three groups (n=13) based on the final irrigation system: Conventional irrigation with syringe and needle (CI), XP-Endo Finisher (XPF), and TDK. 40 mL of 2.5% NaOCl was used for each group. Teeth were scanned ex vivo using a micro-CT before instrumentation, after instrumentation, and after irrigation. Three-dimensional root canal models were evaluated for volume, untouched surfaces, and dentin removal. Data were analyzed using repeated-measures ANOVA, t-test, and Tukey tests (p<0.05).

Results: TDK showed a significant difference in total and cervical third compared to CI and XPF regarding volume and dentin removal analysis (p<0.05), with no significant difference in the apical third compared to XPF (p>0.05). TDK had a lower percentage of untouched volume compared to the other systems in the overall analysis (p<0.05) and at all thirds compared to CI (p<0.05).

Conclusion: Supplementary instruments improve root canal debridement compared to conventional irrigation, particularly in smaller apical diameters and oval-shaped canals of lower incisors. TDK offers enhanced wall contact after root canal preparation and is a viable alternative for complementing debridement. (EEJ-2024-10-158).

Objective: X-ray microtomography (micro-CT or XMT) has previously been used to measure residual voids in root fillings. However, there is no agreement on a protocol that critically identifies and attempts to solve artefacts inherent to the micro-computed tomography technique. This article aims to describe a protocol for automated detection of voids within root-filled canals taking into account the inherent artefacts, with special interest in the partial volume effect. This is to reduce human errors and increase the accuracy and efficiency of void detection.

Methods: Human maxillary premolars (n=33) were shaped, cleaned and root-filled using the cold lateral condensation (CLC) technique. Voids were identified using either individual tomographic slices or the new proposed protocol in which: (1) pre-obturation XMT slices were used to identify the coordinates of the canal space; (2) the post-obturation data sets were aligned to the pre-obturation data sets; (3) the voids were identified as voxels with a grey level below a set threshold after subtraction of pre-obturation from post-obturation data sets. A comparison of the voids from these two methods was made.

Results: The visual inspection of slice by slice of the scanned data resulted in full agreement between the tomographic slices and the results gained from the proposed protocol. This confirmed that this protocol provided an automated, effective and accurate method for detecting voids in root-filled canals.

Conclusion: The proposed protocol provides an automated method to eliminate inaccuracies from XMT artefacts so that accurate volumetric measurements can be easily obtained. (EEJ-2024-02-031).

Objective: The aim of this study was to evaluate and compare the effect of various disinfection protocols on bacterial biofilm and subsequent release of growth factors from radicular dentin.

Methods: One hundred and ninety two extracted single rooted premolars were obtained and contaminated with E. faecalis biofilm for 21 days. The samples were then divided into three main groups - Group I: Irrigation (I) only, Group II: Calcium hydroxide (CH) placement followed by final irrigation and Group III: Triple Antibiotic paste (TAP) placement followed by final irrigation. Each group was further then divided into four sub-groups according to the final irrigating solution used - Sub group A: Saline, Sub group B: 17% EDTA, Sub group C: 1% phytic acid and Sub group D: 0.2%. chitosan nanoparticles. After treatment, the samples were subjected to colony-forming unit (CFU) analysis to determine bacterial reduction and the release of TGF-β1 and VEGF from the root canals, which was quantified using Enzyme-Linked Immunosorbent Assay (ELISA). The data were analyzed using statistical tests.

Results: The maximum reduction in E. faecalis biofilm was observed in Group III (TAP), followed by Group II (CH), and finally Group I (irrigation only). Among the subgroups, the maximum reduction in bacterial biofilm was seen with chitosan nanoparticles, followed by phytic acid, EDTA, and saline. After 24 hours, the highest release of both TGF-β1 and VEGF was observed in the chitosan nanoparticles subgroup, followed by phytic acid, EDTA, and saline. Similar results were seen in the CH and TAP groups.

Conclusion: The study concluded that newer irrigating solutions, particularly 0.2% chitosan nanoparticles, showed superior antibacterial activity and better smear layer removal, leading to greater growth factor release from the radicular dentin. The study also highlighted that TAP placement resulted in maximum bacterial reduction, regardless of the final irrigant used. Furthermore, the release of TGF-β1 was significantly higher than VEGF in all groups. (EEJ-2024-03-045).

Objective: This study aimed to evaluate the antibacterial effectiveness of two concentrations of iodine-potassium iodide (IKI) used as the final irrigating solution during endodontic retreatment.

Methods: Thirty symptom-free root-filled anterior teeth with chronic apical periodontitis (<5*5mm) were included. They were divided into two groups consisting of 15 teeth according to the method of final irrigation. Group 1 were irrigated with 2% IKI, and Group 2 with 5% IKI. The direct bacterial viable count method was performed to determine the number of colony-forming units (CFUs) before and after disinfection. The reduction in bacterial count was assessed, and statistical analysis was performed using Mann-Whitney U tests with a 95% confidence level.

Results: Irrigation with 5% IKI resulted in significantly reduced bacterial counts than 2% IKI irrigation (p<0.05), indicating greater antibacterial effects.

Conclusion: The use of a 5% IKI solution as the final irrigating agent in endodontic retreatment cases with chronic apical periodontitis significantly reduces bacterial counts compared to a 2% IKI solution. The 5% IKI solution therefore exhibited a superior antibacterial effect. Consequently, 5% IKI solution application improves microbiological outcomes and enhances the overall disinfection of the root canal system. (EEJ-2024-08-131).