Pulpitis and apical periodontitis are diseases caused by bacterial infections, and root canal treatment is an effective method to deal with these diseases. The success rate of root canal therapy largely depends on effective infection control. This article reviews root canal infections, the basic principles of infection control in root canal therapyt, challenging issues, fundamental techniques, and recent advancements, thereby providing a reference for clinical practice.

Oral implantology plays an increasingly important role in modern dentistry, with infection control being a critical factor to ensure the success of implant surgeries and patient safety. As implant technology continues to advance, postoperative infections have become a major concern for clinicians and researchers.This article analyzes the common types of infections associated with dental implant surgeries and their underlying mechanisms. It further discusses infection prevention and control strategies from multiple perspectives, including preoperative preparation, intraoperative protocols, postoperative care, and hospital management.Research indicates that infection control must be implemented throughout all phases of treatment. Preoperatively, comprehensive assessment of the patient's systemic health and proper preparation of the oral cavity are essential. Intraoperatively, strict adherence to aseptic techniques and optimization of surgical procedures are crucial. Postoperative strategies, such as appropriate use of antibiotics, structured follow-up, and patient health education, also play a key role in minimizing infection risk.Additionally, a well-established hospital management system is indispensable for effective infection control. This includes the development of institutional protocols, standardization of surgical workflows, staff training programs, and continuous environmental monitoring. The article also highlights the importance of multidisciplinary collaboration in infection control within implant dentistry. Enhanced communication and cooperation among various healthcare professionals can significantly improve the overall quality of care and ensure patient safety and satisfaction.Through an in-depth discussion of infection control measures, this study aims to provide a theoretical foundation and practical guidance for improving the success rate of dental implant surgeries.

Objective: To understand the characteristics of hospital acquired infections in inpatients of the Oral and Maxillofacial Surgery Department and propose appropriate prevention and control strategies. Methods: The data on hospital acquired infections, etiological test results of 49,815 inpatients who underwent surgery in the Oral and Maxillofacial Surgery Ward of Peking University School and Hospital of Stomatology from January 2018 to December 2024, as well as the targeted surveillance data of pulmonary infections in 2024 were reviewed. The characteristics of hospital acquired infections in inpatients of the Oral and Maxillofacial Surgery Department and the control countermeasures were analyzed. Results: The common types of hospital acquired infections in inpatients of the Oral and Maxillofacial Surgery Department were surgical site infections and pulmonary infections. The common pathogens of hospital acquired infections were Pseudomonas aeruginosa, Klebsiella pneumoniae, and Streptococcus viridans. The overall detection rate of multidrug-resistant bacteria was 13.45%, and the detection rate of drug-resistant Escherichia coli was the highest. Conclusions: Effective hospital infection control relies on actively conducting hospital infection monitoring, revealing infection characteristics and risks, and providing a foundation for achieving infection control goals.

Objective: To investigate the clinical practice status of Oral Aesthetics of young dentists and explore the application effect of face-guided virtual teaching of Oral Aesthetics in the standardized training. Methods: Totally 16 young dentists were selected as the study subjects from June 2024 to December 2024 in the Department of Comprehensive Education of Second Clinical Division of Peking University School and Hospital of Stomatology, and the current clinical practice of Oral Aesthetics among young dentists was investigated through a questionnaire survey. Using the stratified randomization method generated by software, the young dentists were divided into two groups: the experimental group and the control group, with 8 members in each group. The experimental group adopted face-guided virtual teaching of Oral Aesthetics, while the control group adopted traditional Oral Aesthetics teaching. The teaching effect was evaluated through theoretical assessment and questionnaire survey. The independent sample T-test and Mann-Whitney U test were used to compare the difference between the teaching effects of the two groups. Results: 43.8% (7/16) of the young dentists believed that they could “master Oral Aesthetics knowledge well”and“complete Oral Aesthetics independently” Only 12.5% (2/16) of young dentists reported being “proficient in using Oral Aesthetics digital software and equipment.” The results of theoretical examination (41.0±3.30) in experimental group were better than those in control group (37.25±2.92), An independent sample t-test was conducted and the difference was statistically significant, (P<0.05). The scores of young dentists in the experimental group in “stimulating the enthusiasm of oral aesthetics learning” and “improving the communication with patients on oral aesthetics” were higher than those in the control group, Mann-Whitney U test was conducted and the differences were all statistically significant, (all P<0.05). Conclusions: Young dentists need to improve their learning degree of Oral Aesthetics. Face-guided virtual teaching of Oral Aesthetics can help stomatologic residents master Oral Aesthetics knowledge, improve teaching effect and satisfaction.

Objective: To understand the occurrence of occupational exposure of dentists in a tertiary stomatological hospital, and to provide effective strategies for improving occupational exposure protection measures. Methods: The occupational exposure registration and follow-up of dentists from January 1, 2019 to December 31, 2023 were investigated and analyzed by retrospective investigation. Results: During this period, a total of 379 cases of occupational exposure occurred among dental doctors in the hospital, including 113 cases of doctors in the hospital, 224 cases of interns and 42 cases of students, the incidence rates were 4.47%, 6.44% and 4.39%, respectively. The interns and doctors with less than one year of working experience were the main population of occupational exposure. The cases of occupational exposure in outpatient department, operating room, oral emergency department and inpatient ward were 304, 60, 13 and 2 cases, respectively The top three leading causes before major incidents are: surgical procedures (instrument-related lacerations or punctures), treatment processes (sharp instrument placement on instrument trays causing collisions), and instrument cleaning and storage procedures. Conclusions: It is necessary to strengthen training and improve awareness of identifying high-risk factors such as places where occupational exposure is prone to occur and improperly placed sharp objects, in order to reduce the occurrence of occupational exposure.

Objective: This case report presents a patient with skeletal ClassⅡ high-angle retrognathic mandible, exploring the application and effects of clear functional appliances in mandibular advancement and occlusal adjustment. Diagnosis and treatment: The patient was a 9-year-old female, complaining of “irregular teeth and protruding mouth” for several years, diagnosed with skeletal ClassⅡ. In the first phase, clear functional appliances were used for mandibular advancement to promote forward growth of the mandible. In the second phase, standard clear aligners were used for occlusal adjustment. Results: After treatment, the position of the lower anterior teeth and the vertical height of the posterior teeth were effectively controlled, with significant improvement in lateral profile and occlusal relationship. Conclusions: Invisible functional orthodontic appliances promote the forward growth of skeletal Class II high angle retrognathia in adolescents, improve facial profile and bite relationship, and have unique advantages.

Objective: This case reports an adolescent patient with skeletal ClassⅡ deep overbite underwent clear aligner orthodontic treatment with tooth extraction, involving Andrews' six elements and jaw growth characteristics. Diagnosis and treatment: The patient received clear aligner orthodontic treatment supported by temporary anchorage devices (TADs), with the design of the occlusal final position based on Andrews' six elements, involving the extraction of teeth$\begin{array}{l|l} 4 & 4 \\ \hline 5 & 5 \end{array}$. Results: The treatment achieved the goals of retraction of the anterior teeth, adjustment of deep bite, and correction of deep overbite, significantly improving the skeletal ClassⅡ malocclusion and convex facial profile. Conclusions: Guided by Andrews' six elements and the developmental characteristics of adolescent jaw bones, this approach enables precise three-dimensional target positioning. Through a single extraction and orthodontic treatment followed by a refined adjustment (45 units + 35 units) plan, it achieves anterior tooth retraction, posterior tooth occlusal cusp-to-fossa interlocking, and vertical control, effectively improving facial aesthetics.

Objective: To develop a novel maxillary sinus floor elevation simulation model using 3D printing technology combined with silicone materials and evaluate its application in the clinical training of dentists and students. Methods: The model was fabricated using 3D printing technology to accurately replicate the anatomical structure of the maxillary sinus. An innovative design featuring an orbital floor fenestration was introduced. Through the fenestration, room-temperature vulcanized silicone materials were applied to the inner surface of the maxillary sinus, simulating the sinus membrane. The model was incorporated into the clinical training of dentists and students. Simulated surgical operations were performed, and a questionnaire-based assessment was conducted to evaluate the teaching effectiveness. Results: The simulation model successfully replicated the anatomical structure and tactile properties of the maxillary sinus. It significantly enhanced the residents’ interest in learning and improved their surgical skills, demonstrating a notable teaching effect. Conclusions: The developed simulation model exhibits excellent structural and mechanical fidelity, as well as high practicality in teaching. It provides an efficient training tool for dental education and holds substantial potential for application and promotion.