Australian Endodontic Journal最新文献

Maxillary molars are prone to endodontic failure due to complex mesio-buccal canal anatomy. With increasing use of cone-beam computed tomography (CBCT), clinicians often have access to scans of homologous or contralateral teeth. This study assessed whether CBCT could predict the presence and configuration of the second mesio-buccal canal (MB2) based on bilateral symmetry. Ninety-nine CBCT scans of bilateral first and second maxillary molars were analysed. MB2 prevalence and Vertucci classification were compared among homologous, adjacent, and contralateral molars. MB2 canals were present in 96.5% of first and 81.3% of second molars. Strong correlations were found between bilateral first molars (91.9%) and bilateral second molars (78.8%), whereas agreement between adjacent or contralateral molars was lower (~60%, p < 0.05). These results indicate that CBCT scans can reliably predict the presence and configuration of the MB2 canal in bilateral maxillary molars, but this correlation does not extend to adjacent or contralateral teeth.

This study aimed to evaluate the effect of silicone oils with varying viscosities (100, 350 and 1000 cSt) and 17% Ethylenediaminetetraacetic acid (EDTA) (1.8 cSt) on the efficiency of removing separated instruments using an ultrasonic device from the curved regions of mesio-buccal canals in mandibular first and second molars. Forty-eight mesio-buccal canals of mandibular first and second molars with curvatures ranging from 15 to 30 degrees were prepared and simulated with separated instruments. Nickel-titanium (Ni-Ti) 25-4% rotary files, measuring 3-4 mm in length, were intentionally fractured within the curvature region of the canals. The samples were randomly divided into four groups (n = 12) based on the lubricant used: EDTA and silicone oils with viscosities of 100, 350 and 1000 cSt at 25°C. Primary outcomes were retrieval time and dentine loss from the canal's inner wall, measured via Cone Beam Computed Tomography (CBCT). Secondary outcomes included the coronal exposure of separated instruments to initiate bodily movement and the accuracy of CBCT versus periapical radiography in measuring fractured file length. Data were analysed using the Shapiro-Wilk test for normality, one-way ANOVA and the Kruskal-Wallis test at a significance level of 0.05. The experimental conditions were homogeneous between groups, with no significant differences in canal curvature (p = 0.907), ultrasonic preparation time (p = 0.632), or actual SI length (p = 0.082). The results showed no significant differences among the groups regarding SI retrieval time (p = 0.797), dentine loss (p = 0.653), or coronal SI exposure (p = 0.653). CBCT measurements demonstrated significantly greater accuracy in determining fractured file length compared to periapical radiography (p < 0.001). Within the limitations of this in vitro study, the findings suggest that silicone oils, regardless of their viscosity, did not provide additional benefits over EDTA in reducing retrieval time or preserving dentine in the mesio-buccal canals of mandibular molars. However, CBCT proved more accurate than periapical radiography in measuring SI length. Despite the lack of significant effects of silicone oils with higher viscosity, EDTA remains clinically preferred due to its inherent chelating properties. Further research is needed to confirm or refute these findings.

This study evaluated the effect of glycolic acid (GA) as a final irrigant on the long-term bond strength of AH Plus and Bio-C Sealer. Forty-eight single-rooted teeth were assigned to four groups (n = 12): ethylenediaminetetraacetic acid (EDTA) + AH Plus, glycolic acid + AH Plus, EDTA + Bio-C Sealer, and glycolic acid + Bio-C Sealer. The bond strength and failure pattern were evaluated immediately and after 6 months, while the interface adaptation and sealer penetrability were also assessed. Immediate bond strength did not differ between groups, but after 6 months AH Plus showed higher values than Bio-C Sealer. The failure pattern was similar among all groups at both evaluation time points. EDTA + AH Plus exhibited superior interface adaptation compared with EDTA + Bio-C Sealer, particularly in the cervical third. Sealer penetrability was comparable among groups. Glycolic acid produced similar outcomes to EDTA, and AH Plus maintained greater bond strength over time.

Persistent bacterial infection remains the primary cause of root canal treatment failure, posing a significant challenge in endodontics. Enterococcus faecalis, with its ability to form biofilms and resist conventional disinfectants, is one of the most commonly isolated species in failed cases. Herein, we developed a novel polydopamine (PDA) nanoparticle-based phototherapy system activated by 808 nm near-infrared (NIR) light for enhanced root canal disinfection. The PDA + NIR group exhibited a significantly superior antibacterial effect compared to 2.5% NaOCl, achieving a bactericidal rate of 97.87%. SEM and TEM observations revealed that PDA + NIR treatment caused complete bacterial cell disintegration and ultrastructural destruction, whereas 2.5% NaOCl only induced partial surface damage. Furthermore, PDA + NIR effectively eradicated mature E. faecalis biofilms in simulated root canal models. These findings demonstrate that PDA-mediated NIR phototherapy possesses powerful bactericidal and antibiofilm capabilities. This nanotechnology-based approach may offer a promising alternative strategy for clinical root canal disinfection.

This study aimed to systematically evaluate the risk factors associated with the failure of separated instrument removal. A comprehensive search of PubMed, Embase and the Cochrane Library was performed to identify studies reporting on the success rates of separated instrument removal, covering the period from 1988 to 2025. The meta-analysis was performed using Stata 17.0. Seven studies encompassing 922 patients with separated instruments were included. The pooled success rate of separated instrument removal was 66%. Meta-analysis identified several significant risk factors for removal failure: instrument location in posterior teeth, mandibular teeth, the apical third of the canal, the apical side of a curved canal, and root curvature exceeding 30°. Current evidence indicates that unfavourable anatomical factors significantly increase the likelihood of failed instrument retrieval. These findings underscore the importance of preoperative assessment and careful case selection when planning separated instrument removal procedures.

To assess the prevalence of apical periodontitis (AP), alveolar bone loss (ABL), and the frequency of root-filled (RF) teeth in athletes, digital panoramic radiographs were obtained from 617 athletes (57.5% males; 42.5% females) with a mean age of 25.4 years (±2.8), evaluating 15.239 teeth. AP was classified using the Periapical Index (PAI). ABL was recorded when bone loss exceeded one-third of root length in more than two teeth. The RF teeth and periapical status were also recorded. Intra-examiner agreement was high (Kappa = 0.87). AP was found in 209 (33.9%) of athletes and 357 (2.3%) of teeth; 89 (42.6%) had multiple lesions. RF teeth were present in 226 (36.6%) of individuals; 189 (52.9%) of these showed AP. Additionally, 168 (47.1%) of AP cases were in non-RF teeth. ABL was detected in three participants (0.49%). AP was prevalent among Olympic athletes, in both RF and non-RF teeth, indicating high endodontic treatment needs.

This ex vivo study characterised the mesial root morphology of mandibular first molars with a middle mesial canal (MMC) using micro-CT. Among 469 scanned molars, 42 (8.96%) presented an MMC. Morphological parameters analysed included canal configuration, chamber orifice features, dentine thickness, isthmus type, and aspect ratio. Twenty-four configurations were found, with the confluent type most prevalent (90.48%). Three separate orifices occurred in 64.29% of teeth, and MMCs were mainly in the coronal and middle thirds. Fully independent MMCs were rare (2.38%). Mean dentine thickness 2 mm below the furcation was 1.31 mm (MB), 1.03 mm (MMC) and 1.28 mm (ML). The mean aspect ratio was 2.90. Accessory canals appeared in 28.58%, and an independent MMC foramen in 38.09%, mainly on the mesial wall. Type III isthmus predominated (52.38%). Mesial roots with MMCs exhibit marked anatomical variability, with thin dentine around the MMC requiring careful endodontic management.

This study evaluated and compared the accuracy, consistency, readability, and information quality of three LLM-based chatbots, namely ChatGPT-5, Claude AI (Sonnet 4.0), and Perplexity (Mistral Large 2), in addressing traumatic dental injury questions. Forty true/false statements were submitted to each chatbot three times at weekly intervals to assess accuracy and consistency. Additionally, chatbot responses for 25 open-ended case-based questions were evaluated for readability, understandability and actionability, information reliability and quality. For true/false questions, Perplexity showed the highest accuracy, followed by Claude and ChatGPT. For open-ended responses, ChatGPT excelled in readability (FRE: 62.4 ± 7.6), Perplexity in understandability (91.0 ± 4.3) and actionability (93.0 ± 6.4) and Claude in information reliability (mDISCERN total: 61.2; no variability observed). All chatbots achieved acceptable global quality scores (> 4.4). These findings emphasise the complementary role of chatbots in dental trauma management. Tool selection should be based on intended use, while continued human oversight remains essential in clinical decision-making.

Head and neck radiotherapy (HNRT) can expose teeth to moderate radiation doses, yet the effects on root dentine under clinically relevant conditions remain unclear. This in vitro study compared dentine subjected to 0, 30, or 50 Gy IMRT. Palatal roots from 35 maxillary molars were allocated to non-irradiated, 30 Gy (oropharyngeal simulation), or 50 Gy (maxillary simulation). Flexural strength, Vickers microhardness, and Raman spectroscopy were assessed, while SEM was qualitatively evaluated. Mechanical and chemical properties did not differ among groups (p > 0.05). SEM, however, revealed dose-dependent microstructural changes: fissures and partial tubule obliteration at 30 Gy, and more frequent cracks and complete obliteration at 50 Gy. Under these in vitro simulated conditions, radiotherapy doses preserved bulk properties despite structural alterations. These findings should be interpreted within the limitations of the model, as interactions among experimental factors may influence how microstructural changes affect dentine mechanics.

This systematic review analysed the analgesic efficacy of low-level laser therapy (LLLT) compared to conventional drug therapy and placebo for postoperative pain in endodontics. PubMed, PubMed Central, Scopus, LILACS, SciELO, Virtual Health Library, Embase and Open Gray were searched. Clinical trials assessing pain intensity were included. Risk of bias was assessed using the RoB 2.0 tool. Nine studies were included, five classified as having low risk of bias. Eight studies demonstrated that LLLT was more effective in modulating postoperative pain compared to control interventions. Meta-analysis of five studies (I² = 31%) showed statistically significant pain reduction with LLLT in comparison with placebo after 1 day (VAS mean difference = -0.56; 95% CI = [-0.74 to -0.38]; p < 0.001). LLLT may improve postoperative pain control after endodontic treatment. Additional high-quality studies are necessary to strengthen the evidence base for LLLT's analgesic efficacy in endodontic applications.