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Aim: The regenerative capacity of dental pulp relies on the odonto/osteogenic differentiation of dental pulp cells (DPCs), but dynamic microenvironmental changes hinder the process. Bone morphogenetic protein 9 (BMP9) promotes differentiation of DPCs towards an odonto/osteogenic lineage, forming dentinal‐like tissue. However, the molecular mechanism underlying its action remains unclear. This study investigates the role of DLX6 antisense RNA 1 (DLX6‐AS1) in odonto/osteogenic differentiation induced by BMP9. Methodology: Custom RT2 profiler PCR array, quantitative Real‐Time PCR (qRT‐PCR) and western blots were used to investigate the expression pattern of DLX6‐AS1 and its potential signal axis. Osteogenic ability was evaluated using alkaline phosphatase and alizarin red S staining. Interactions between lncRNA and miRNA, as well as miRNA and mRNA, were predicted through bioinformatic assays, which were subsequently validated via RNA immunoprecipitation and dual luciferase reporter assays. Student's t‐test or one‐way ANOVA with post hoc Tukey HSD tests were employed for data analysis, with a p‐value of less than.05 considered statistically significant. Results: DLX6‐AS1 was upregulated upon BMP9 overexpression in DPCs, thereby promoting odonto/osteogenic differentiation. Additionally, miR‐128‐3p participated in BMP9‐induced odonto/osteogenic differentiation by interacting with the downstream signal MAPK14. Modifying the expression of miR‐128‐3p and transfecting pcMAPK14/siMAPK14 had a rescue impact on odonto/osteogenic differentiation downstream of DLX6‐AS1. Lastly, miR‐128‐3p directly interacted with both MAPK14 and DLX6‐AS1. Conclusions: DLX6‐AS1 could regulate the odonto/osteogenic differentiation of DPCs under the control of BMP9 through the miR‐128‐3p/MAPK14 axis. [ABSTRACT FROM AUTHOR]

Endodontic microsurgery is one effective method for preserving teeth affected by periapical disease, and is also an essential technique for treating difficult cases. However, due to the restricted operating space at the posterior site and the proximity of the root apex to the maxillary sinus, endodontic surgery in the posterior maxillary area represents great challenges. This article summarizes the anatomical relationship between the maxillary sinus and the maxillary posterior teeth, the influence on endodontic microsurgery, and the application of assistive techniques on maxillary posterior teeth, such as 3D-printed surgical guides and ultrasonic osteotomes. Literature review results show that the spatial relationship between the apex of maxillary posterior teeth and the maxillary sinus is usually divided into three categories: the apex enters the maxillary sinus; the apex contacts the bottom of the maxillary sinus; and there is a distance between the apex and the bottom of the maxillary sinus. CBCT should be performed before the operation, and the periapical state of the tooth and the maxillary sinus and the distance between the lesions and the sinus floor should be considered to evaluate the difficulty of the operation. Meanwhile, during surgery, equipment such as surgical guides, endoscopes and ultrasonic osteotomes should be used to ensure that the operation is safer, reliable, precise and less invasive, but the clinical popularity of ultrasonic osteotomes still needs further promotion. Moreover, high-quality clinical studies on the long-term effects of micro-apical surgery in the posterior maxillary area are still lacking.

Objective This study aims to compare the incidence of dentinal microcracks produced by ProTaper Universal (PTU) and ProTaper Gold (PTG) file systems during root canal procedures in different curved canals using a dyeing technique. Methods Sixty extracted human molars were divided into 3 groups of 20 samples each in terms of root curvature (mild bending group, 10 °-19 °; moderate bending group, 20 °-29 °; severe bending group, 30 °-39 °). Ten samples of each group were then randomly allocated to the PTU and PTG file systems. After preparation, all roots were stained using a dyeing method and sectioned at the most curved plane and 2 mm below and above the most curved plane with a low-speed saw under cold water. A stereomicroscope was used to inspect dentinal microcracks at 60 × magnification, and differences between these three instrument groups were analyzed using the chi-square test. Results The PTG file system induced significantly fewer dentinal microcracks for total, incomplete and complete cracks (P < 0.05), and the effect was more obvious with increasing canal curvature. Conclusion With the limitations of this in vitro study, it can be concluded that ProTaper Gold can result in fewer dentinal microcracks than ProTaper Universal.

This study investigated the root canal morphology of fused‐rooted mandibular second molars based on the pulp chamber floor (PCF) and analysed the correlation between the external morphology of the radicular groove, and the internal morphology of the PCF and root canal configuration. A total of 291 fused‐rooted teeth collected from the Chinese population were scanned using micro‐computed tomography and a dental operating microscope was used for observing the PCFs. The classification of the PCF and root canal configuration were identified according to modified Min et al.'s and Gao et al.'s classifications, respectively. Additionally, a new radicular groove classification was proposed. The correlation among these morphological characteristics was investigated using the chi‐square test and Fisher's exact test (p < 0.05). The results showed that 74.2% of teeth had C‐shaped PCFs, while 21.0% had non‐C‐shaped PCFs. As for the root canal configurations, 37.5% of teeth were merging type, 40.9% were symmetrical type, and 14.8% were asymmetrical type. Statistical analysis revealed a significant correlation between the PCF types and the root canal configurations (p < 0.001). The dominant root canal types for teeth with C‐shaped PCFs were merging and symmetrical types, while the asymmetrical type was not identified in non‐C‐shaped PCFs. In addition, significant morphological association between the root canals and radicular grooves was also revealed (p < 0.001). Teeth with different PCF morphologies exhibit specific patterns of root canal category distribution. Understanding the morphological nuances of the root canal based on the PCF can assist clinicians in predicting and identifying the canal configuration beneath the visible orifice. [ABSTRACT FROM AUTHOR]

Objective To investigate the diagnosis, treatment and prognosis of nonodontogenic periapical lesions and to provide a reference for clinical diagnosis and treatment. Methods A case of a patient with right upper molar pulp with apical penetration and local occlusion admitted to the West China Stomatological Hospital of Sichuan University was retrospectively analyzed, and the curative effect of microapical surgery and pith preservation was also analyzed. Results The imaging features of tooth 16 showed periradicular radiolucency combined with local radiopaque lesions around the distal buccal apical area. Endodontic microsurgery was performed under local anesthesia. Soft tissue coverage was observed in the distal buccal apical area during the surgery, and no radiopaque tissue was detected. The distal buccal root apex was cut by 3 mm, and mineral trioxide aggregate was used for root-end backfilling. The postoperative pathological results revealed fibrous connective tissue. One-week recall X-ray examination showed tight root-end backfilling and no periradicular radiolucency; an electrical test of pulp vitality showed positive results. The four-year follow-up showed that there was no discoloration in tooth 16 and no significant difference in thermal and electrical tests of pulp vitality compared with control teeth. Combining the clinical manifestations, imaging features, surgical exploration results and pathological reports, the case was most likely to be cemental hypoplasia. Through the literature review, the treatment and healthy pulp preservation of such cases by endodontic microsurgery under the premise of preserving teeth has not been reported.Conclusion For maxillary posterior teeth with periapical lesions but healthy pulp, accurate estimation of pulp status, endodontic microsurgical exploration and application of bioactive materials can achieve vital pulp preservation while removing the lesions.

Introduction: Accurate inlay preparation is extremely important in pre‐clinical training. However, there is a lack of tools to guide students to efficiently practise inlay preparation. Therefore, a 3D‐printed coloured tooth model for inlay preparation was designed to guide beginners to practise inlay preparation by themselves according to different colour prompts. This study aimed to evaluate the benefits of using a 3D‐printed coloured tooth model in the pre‐clinical training on inlay preparation. Materials and Methods: Twenty‐eight students in their fourth‐year undergraduate dental program participated in this study. The participants were randomly assigned to two groups for the inlay preparation. Group 1 prepared a plain tooth model for the first and fourth attempts and a 3D‐printed coloured tooth model for the second and third attempts (n = 14). Group 2 prepared four plain tooth models (n = 14). The first and fourth tooth models prepared by both groups were scored using an evaluation system (Fair Grade 2000, NISSIN). Next, questionnaires answered by students were used to evaluate the benefits of using a 3D‐printed coloured tooth model and self‐evaluate hands‐on ability using a grading system (1 = strongly agree, 2 = agree, 3 = neutral, 4 = disagree, and 5 = strongly disagree). The scores were evaluated statistically using the Mann–Whitney U test, and the given grades are displayed as percentages and mean values. Results: There was an overall increase in the clinical confidence of all students after repeated attempts to prepare an inlay; however, students from group 1, who had used the 3D‐printed coloured tooth model, had more positive experiences and comments. The 3D‐printed coloured tooth model for inlay preparation has been widely praised by participants. Comparing the average score of the first and fourth preparations, the average score of group 1 increased by 12% (Ø 54.46 ± 8.33, Ø 61.11 ± 7.13, p =.090), while that of group 2 increased by 0.72% (Ø 56.39 ± 9.59, Ø 56.80 ± 8.46, p =.925). Conclusion: Students favoured the use of the 3D‐printed coloured tooth model, and this improved the average score for inlay preparation. The 3D‐printed coloured tooth model for inlay preparation is expected to play an important role in dental education in the future. [ABSTRACT FROM AUTHOR]

Objective: Periodontitis is an inflammatory disease that involves an imbalance in the oral microbiota, activation of inflammatory and immune responses, and alveolar bone destruction. Macrophage migration inhibitory factor (MIF) is a versatile cytokine involved in several pathological reactions, including inflammatory processes and bone destruction, both of which are characteristics of periodontitis. While the roles of MIF in cancer and other immune diseases have been extensively characterized, its role in periodontitis remains inconclusive. Results: In this review, we describe a comprehensive analysis of the potential roles of MIF in periodontitis from the perspective of immune response and bone regulation at the cellular and molecular levels. Moreover, we discuss its potential reliability as a novel diagnostic and therapeutic target for periodontitis. Conclusion: This review can aid dental researchers and clinicians in understanding the current state of MIF‐related pathogenesis, diagnosis, and treatment of periodontitis. [ABSTRACT FROM AUTHOR]