Yeon-Jee Yoo

Aim: To prospectively compare treatment outcomes for orthograde canal obturation using Ortho MTA III (OMTA) with the continuous wave of compaction (CWC) using gutta‐percha (GP) and AH Plus sealer, and to identify associated predictive factors. Methodology: Informed consent was obtained (110 patients), and single‐ or two‐rooted permanent teeth ( n = 120) diagnosed with pulp necrosis (or previously treated) and asymptomatic apical periodontitis or chronic apical abscess (periapical index, PAI ≥ 3) were randomly assigned to two groups ( n = 60/group). The canals were prepared to a minimal apical size #40 (ISO) based on their initial file size, disinfected and obturated by either CWC or OMTA using an enhanced disinfection protocol (GP disinfected, new gloves after each intraoperative radiograph and before starting obturation). Clinical and periapical radiographic examinations were conducted by two calibrated, independent endodontists during follow‐up periods of at least 12 months. Success rates and associated predictive factors (tooth‐, operator‐ and patient‐related) were analysed statistically using binary and multiple logistic regression ( p < 0.05). Results: The median recall period was 30 months (14–48 months), and 104 teeth were finally analysed (recall rate: 86.67%). No significant differences in success rate were observed between the groups ( p > 0.05) under both loose (OMTA: 88.24%, CWC: 83.02%) and strict criteria (OMTA: 64.71%, CWC: 58.49%). Multivariate analysis revealed that age (OR = 5.735, 95% CI: 1.286–25.577, p = 0.022), periapical lesion size (OR = 6.596, 95% CI: 1.397–31.138, p = 0.017) and PAI score (OR = 2.081, 95% CI: 1.047–4.136, p = 0.036) were significant predictors of treatment failure. Conclusions: Orthograde obturation of infected canals with Ortho MTA III demonstrated comparable success and treatment outcomes to those filled with GP and sealer by CWC, supporting its potential as a clinically viable alternative for the obturation of infected root canals. Trial Registration: cris.nih.go.kr registration number: KCT00099939

Introduction: Denosumab is a potent RANKL inhibitor used for osteoporosis, yet its impact on root canal treatment (RCT) outcomes remains less understood compared to bisphosphonates. This study evaluated the periapical healing outcomes of RCT in patients receiving denosumab and identified clinical variables influencing treatment success. Methods: This retrospective case-control study included 20 patients with osteoporosis receiving denosumab who underwent RCT at a major tertiary hospital between July 2014 and June 2024 (group D), along with 20 age- and sex-matched systemically healthy controls (group C). Among 116 denosumab-treated patients screened, 20 met the strict selection criteria and were enrolled as the study group. Periapical healing was assessed using the Periapical Index (PAI) at a minimum follow-up of 3 months after treatment. Various clinical and radiographic factors, including initial PAI scores and sealer extrusion, were analyzed using logistic regression to determine their impact on healing rates. Results: The median follow-up period was 534 (287–956) days for group D and 421 (235–1045) days for group C. The overall periapical healing rates were 75.0.% in the denosumab group and 90.0% in the healthy control group ( P = 0.407). Multivariable logistic regression analysis did not identify any statistically significant predictors of healing outcomes. However, higher initial PAI scores (OR = 7.610, P = 0.088) and sealer extrusion (OR = 3.70, P = 0.185) were associated with less favorable outcomes in the multivariable model. Sealer extrusion was significantly associated with healing outcomes in univariate analysis ( P = 0.034). Conclusions: Within the limitations of this study, there was no statistically significant difference in the proportion of healed cases between patients receiving denosumab therapy and healthy controls. These findings suggest that non-surgical root canal treatment may remain a viable tooth-preserving treatment option for patients receiving denosumab therapy. Careful apical control and long-term follow-up may be particularly important in patients presenting with large pre-existing periapical lesions and sealer extrusion.

Restorative Dentistry and Endodontics news: celebrating the 50th anniversary of the journal

Purpose: This study aimed to investigate whether the amount, chemical characteristics, and morphological patterns of intratubular biomineralization are similar under both in vivo and in vitro conditions.Methods: Root canal treatment, which included preparation, irrigation, and obturation with gutta-percha plus a premixed hydraulic bioceramic endodontic sealer, was performed on seven teeth in seven patients. These teeth were then extracted between 6 months and 5 years later for reasons unrelated to the endodontic therapy. Seven extracted, single-rooted human teeth were also endodontically treated using the same procedure. The in vitro-treated teeth were stored in phosphate-buffered saline at room temperature for 30 days. Scanning electron microscopy was used to analyze the amount and morphology of intratubular biomineralization in all 14 teeth. Energy-dispersive X-ray spectroscopy was also performed to identify the elements present in the dentinal tubules.Results: There was no significant difference in the measured amount of biomineralization between the two groups. However, the morphological patterns of precipitates within the dentinal tubules differed between the in vivo (granular) and in vitro (plate-like) conditions.Conclusion: These results indicate that quantitative evaluation of the amount of biomineralization in vitro is a feasible alternative for replication of in vivo conditions.

Background: To assess the effect of indirect ultrasonic activation on the root canal obturation with a premixed calcium silicate cement (CSC). Methods: Twenty-six single-rooted premolars were sectioned to the length of 11 mm. All the roots were instrumented using ProTaper Next instruments and randomly assigned to either the control (n = 4) or experimental (n = 22) groups according to root canal obturation methods. Root specimens allocated to experimental groups were obturated with Endocem MTA, with (group EMU) or without (group EM) indirect ultrasonic activation (n = 11/group). Root specimens obturated with gutta-percha served as positive and negative (after nail varnish coating) controls. Intraoral radiograph images were used to assess the presence or absence of voids in the coronal, middle, and apical thirds of each specimen. The specimens were connected to a nanoscale fluid filtration device to measure quantitative leakage data. Data was statistically analyzed with a significance level of 0.05. Results: There was no significant difference in the voids formation between the two groups (p > 0.05), but specimens in group EMU presented significantly higher quantitative leakage than those in group EM (p < 0.05). Conclusions: Within the limitation of this study, indirect ultrasonic activation of premixed CSC did not affect the void formation but presented higher quantitative leakage. Future research incorporating micro-CT imaging would enable a more precise and comprehensive analysis, providing valuable insights into the root canal obturation with premixed CSCs.

Aim: This study investigated the correlation between microbiota of caries‐free enamel and caries‐affected dentine biofilms and that of root canals with primary apical periodontitis, by using an Illumina MiSeq platform.Methodology: Biofilm from caries‐free enamel surface (Biofilm‐C) or caries‐affected dentine (Biofilm‐E) and root canal paper point samples (Canal) were collected from 31 teeth with primary apical periodontitis. Microbial composition was analysed by amplicon sequencing that targeted the V3–V4 region of 16S rRNA gene. Alpha and beta diversities of bacterial communities between sampling sites were compared using the Kruskal–Wallis test and pairwise permutational multivariate analysis of variance, respectively. Differentially abundant taxa identified using MaAsLin2 were adjusted for multiple comparisons using the Benjamini–Hochberg method.Results: Totals of 16 phyla, 130 genera and 314 species were identified. Distinct and shared bacterial communities were observed between biofilm and canal samples. No significant differences in alpha diversity were observed across all sampling sites. A total of 32 genera including Acinetobacter, [Eubacterium], Dialister, Erysipelotrichaceae UCG‐006, Lawsonella, W5053, Phocaeicola, Mogibacterium, Pyramidobacter and Parvimonas were more abundant in Canal samples compared to both Biofilm‐C and Biofilm‐E. The genera Hallella, Lactobacillus, Shuttleworthella, Olsenella, Cryptobacterium, Alloprevotella, Phocaeicola, Limosilactobacillus, Selenomonadaceae and Anaeroglobus were increased significantly in Biofilm‐E compared to Biofilm‐C. Hallela multisaccharivorax, Olsenella uli, Lactobacilllus gasseri, Selenomonadaceae species and Scardovia inopinata exhibited higher abundance in both Biofilm‐E and Canal, than Biofilm‐C. These differences in bacterial composition among sampling sites, including the increased presence of specific taxa in caries‐affected dentine and root canals, suggest that these microorganisms may contribute to the development of primary apical periodontitis.Conclusion: Bacterial community structure differed significantly between biofilm and root canal samples, but showed no significant differences among biofilm samples based on dental caries status. However, some taxa were shared among caries‐affected lesions, including dentine and root canals. H. multisaccharivorax, O. uli, L. gasseri, Selenomonadaceae species and S. inopinata exhibited higher abundance in caries‐affected dentine and root canals with primary apical periodontitis, suggesting that specific bacteria in caries‐affected dentine play a crucial role in the development of root canal infections and the pathogenesis of primary apical periodontitis.

Background: To investigate the efficacy of a nickel-titanium (NiTi) file with an automated computerized numerical control (CNC) system for root canal shaping. Methods: The movement of the automated device and the insertion angle were investigated. In Experiment 1, simulated resin root canals were randomly divided into four groups (n = 20): manual downward movement using a handpiece (Group 1), vertical downward movement by CNC (Group 2), reciprocating up and down movement by CNC (Group 3), and spiral up and down movement by CNC (Group 4). In Experiment 2, five different insertion angles of the NiTi file were evaluated (n = 20). Four parameters were used to evaluate the shaping ability: change in the working length, central axis offset, curvature variation, and preparation time. Groups were compared using one-way analysis of variance (ANOVA) with significance was set at P < 0.05. Results: The change in central axis position in the curved part of the root canal was found to be smaller in Group 4 than in other groups (P < 0.05). The curvature changes and preparation time of Groups 1 and 4 were significantly reduced compared with Groups 2 and 3 (P < 0.05). The variation in working length and curvature in the 5° insertion angle group was significantly smaller than in the other groups (P < 0.05). Conclusions: A spiral up and down movement, controlled by the CNC machine, and 5° insertion angle, maintained original root canal shape more precisely than other methods.