INTRODUCTION: Antimicrobial resistance (AMR) poses a critical global health threat, with millions of deaths attributed to it annually. Antibiotic stewardship to combat AMR is the responsibility of all healthcare professionals. Despite evidence suggesting that it is unnecessary, dentists routinely prescribe prophylactic antibiotics following third molar (3M) surgeries. METHOD: This mixed-methods study examined the behavioural barriers influencing antibiotic prescribing practices within the Division of Oral and Maxillofacial Surgery at the National University Centre for Oral Health Singapore. This study used the capability, opportunity and motivation for behavioural change or COM-B framework to implement interventions targeting the behavioural barriers. RESULTS: Pre- and post-intervention data over 6 months showed a significant reduction in antibiotic prescriptions from 84.45% to 20.89%, following the implementation of COM-B strategies (P<0.001). Qualitative feedback from focus group discussions highlighted a positive shift in clinicians' attitudes towards antibiotic reduction, acknowledging the minimal infection risk associated with non-prescribing practices. Notably, complication rates remained stable throughout the study period, indicating no adverse effects from reduced antibiotic usage. CONCLUSION These findings demonstrated that the COM-B model can be successfully applied to modify deeply ingrained prescription habits, and underscored the effectiveness of a structured behavioural change intervention in enhancing compliance with antibiotic stewardship guidelines. The study advocates continuation of initiatives to sustain this positive trend and mitigate AMR in clinical practice.
Humans ; Molar, Third/surgery* ; Anti-Bacterial Agents/therapeutic use* ; Singapore ; Antimicrobial Stewardship/methods* ; Practice Patterns, Dentists'/statistics & numerical data* ; Antibiotic Prophylaxis ; Female ; Attitude of Health Personnel ; Male ; Tooth Extraction ; Adult ; Focus Groups ; Practice Patterns, Physicians'

OBJECTIVE: To evaluate the clinical and radiographic efficacy of micro crestal flap-alveolar ridge preservation following extraction of mandibular molars with severe periodontitis compared with natural healing, and to preliminarily propose the surgical indication. METHODS: A retrospective analysis was conducted on clinical data from patients with mandibular molars with severe periodontitis either receiving micro crestal flap-alveolar ridge preservation (MCF-ARP group) or undergoing natural healing in department of periodontology, Peking University School and Hospital of Stomatology from September 2013 to June 2021. Cone-beam computed tomography scannings performed before/immediately after extraction (as baseline) and repeated before implantation (after the extraction socket healing) were used to measure the ridge width, height and volumetric changes of the sockets, and the proportion of guided bone regeneration (GBR) during implant therapy were compared between the two groups. RESULTS: Between baseline and healing, significant differences in changes of MCF-ARP group [(8.34±2.81) mm] and natural healing group [(3.82±3.58) mm] in the distances from mandibular canal to center of the tooth socket were recorded (P < 0.001). The ridge width at 1 mm below the most coronal aspect of the crest increased by (3.50±4.88) mm in the MCF-ARP group but decreased by (0.16±5.70) mm in the natural healing group, respectively (P=0.019). After healing, the MCF-ARP group showed the distances from mandibular canal to center of the tooth socket >8 mm in all the cases, with 97.1% exceeding 10 mm. Natural healing group displayed 23.1% of the cases with center bone height < 8 mm and 61.5% exceeding 10 mm. Volume changes at the buccal and lingual aspect as well as the total socket were significantly greater in the MCF-ARP group compared with natural healing group (P < 0.001).At the time of implantation, GBR was performed in 5 out of 68 subjects (8.3%) in the MCF-ARP group, whereas 8 out of 26 subjects (30.8%) in the natural healing group required GBR, reflecting significant difference (P=0.003). CONCLUSION In the sites of mandibular molars with severe periodontitis, when the distances from mandibular canal to center of the tooth socket was not enough (less than 7 mm), clinicians could consider performing the micro crestal flap-alveolar ridge preservation to achieve augmentation for alveolar ridge and reduce the proportion of guided bone regeneration during implant therapy to reduce the difficulty and risk of injuries during implant therapy.
Humans ; Tooth Extraction ; Retrospective Studies ; Surgical Flaps ; Molar/surgery* ; Mandible/surgery* ; Female ; Periodontitis/surgery* ; Male ; Adult ; Middle Aged ; Cone-Beam Computed Tomography ; Alveolar Ridge Augmentation/methods* ; Alveolar Process/surgery* ; Tooth Socket/diagnostic imaging* ; Dental Implantation, Endosseous/methods*

OBJECTIVE: To compare the influence of different emergence profile of implants in mandibular molar on the peri-implant soft tissue. METHODS: Forty-four implants were divided into two equal groups by mucosal thickness, ≥2 mm (group A) or < 2 mm (group B), and were randomly included in the test group and the control group. In the control group, the patients were treated by a prosthesis with no transmucosal modifications (subgroups A1 and B1). In groups A1 and B1, the prostheses maintained the original emergence profile of the healing abutment. In the test group, the prostheses were designed based on a width-to-height ratio (W/H) of 1.3 ∶ 1 (subgroups A2 and B2). In group A2, the buccal transmucosal configuration design was slightly concave, and in group B2, the prostheses were designed with convex buccal transmucosal configuration. Assessments were made before delivery of the definitive restoration (T0), one month (T1) and 12 months (T2) after loading. The soft tissue and prosthesis information were obtained by intraoral scan and were converted to digital models. The digital models of different time were superimposed together. Buccal mucosal W/H, emergence angle (EA) and buccal mucosal margin recession (ΔGM) were measured. RESULTS: One year after loading, the buccal mucosal margin recession in the test group (groups A2 and B2) was significantly lower than that in the control group (groups A1 and B1). The ΔGM in group A2 was significantly lower than that in group A1 (P=0.033), but in groups B1 and B2, it was not significantly different. The W/H in group A2 increased significantly one month after loading, but remained stable at one year. In the A1 group, the W/H changed little from initial to one month, but increased significantly at one year after loading. The W/H in group B2 remained stable from the beginning to one year, while in group B1, it changed little one month after loading, but increased significantly by one year. CONCLUSION When the initial mucosal thickness was ≥2 mm, the slightly concave prosthesis designed based on the biological W/H significantly maintained the level of buccal mucosa. When the mucosal thickness was < 2 mm, the slightly convex prosthesis design maintained a more stable W/H over one year.
Humans ; Mandible/surgery* ; Molar/surgery* ; Male ; Female ; Adult ; Middle Aged ; Dental Prosthesis Design ; Dental Implants ; Dental Implantation, Endosseous/methods*

OBJECTIVE: To investigate the clinical application effect of the along-axis extraction method in the extraction of impacted mandibular third molars (IMTM) and to compare the biomechanical characteristics of different root extraction techniques through three-dimensional finite element analysis. METHODS: A total of 68 patients requiring IMTM extraction were enrolled and randomly divided into two groups: the experimental group underwent the along-axis extraction method, while the control group underwent the traditional buccal bone removal and root extraction method. The duration of the procedure, intraoperative and postoperative complications were recorded. Three-dimensional finite element analysis further revealed the stress distribution in the tooth root, jawbone, periodontal ligament, and mandibular canal during different root extraction methods. RESULTS: The duration of root extraction, pain score and swelling on the first postoperative day in the control group were (7.87±3.90) min, 4.62±1.90 and (11.37±5.12) mm, respectively, which were significantly higher than those in the experimental group [(5.74±2.37) min, 3.87±1.19 and (7.22±3.39) mm, respectively]. The root fracture rate and lingual bone plate fracture rate in the control group were significantly higher than those in the experimental group (P < 0.05). The results of finite element analysis showed that the control group ' s lingual al-veolar bone had the higher peak equivalent stress, and lingual bone plate fracture was prone to occur. The periodontal ligament of the experimental group had the higher equivalent stress value, making it more likely to rip and more likely to cause root displacement. When subjected to force, the experimental group' s instantaneous root displacement was higher, but the control group ' s root displacement was more pronounced in the lingual direction. CONCLUSION This study suggests that the along-axis extraction me-thod can not only effectively shorten the operative time but also reduce postoperative complications after extraction of impacted mandibular third molars, and enhance the safety of the operation and the patient' s comfort. Three-dimensional finite element analysis shows the biomechanical characteristics of various root extraction techniques visually, serves as a valuable guide for choosing and refining clinical surgical techniques, and confirms that extracting a tooth' s root along its long axis yields better clinical results.
Humans ; Finite Element Analysis ; Tooth, Impacted/surgery* ; Tooth Extraction/methods* ; Molar, Third/surgery* ; Mandible/surgery* ; Imaging, Three-Dimensional ; Female ; Adult ; Biomechanical Phenomena ; Male ; Tooth Root/surgery* ; Young Adult ; Adolescent

Fused teeth are usually formed by the partial or complete fusion of two normal tooth germs during the development process and belong to dental developmental abnormalities. Fused teeth are relatively rare clinically, and those occurring in the posterior tooth area are even rarer. This article reports a case of fused teeth between the first permanent molar and the second permanent molar in the right mandible. This fused tooth had a complex root canal anatomical structure (seven root canals). The number and location of the root canals were analyzed by cone beam computed tomography, and root canal treatment was successfully completed with the assistance of microscope.
Humans ; Molar/diagnostic imaging* ; Mandible ; Dental Pulp Cavity/abnormalities* ; Cone-Beam Computed Tomography ; Root Canal Therapy/methods* ; Fused Teeth/surgery*

OBJECTIVE: To compare the clinical effects of pulpotomy with two kinds of calcium silicate materials, and to evaluate the formation of dentin bridge and pulp calcification after pulpotomy of adult permanent teeth. METHODS: Patients who visited the General Department of Peking University School and Hospital of Stomatology from November 2017 to September 2019 and planned for pulpotomy on permanent premolars and molars with carious exposed pulp were selected. They were randomly divided into two groups. Bioceramic putty material iRoot BP (iRoot group, n=22) and mineral trioxide aggregate MTA (MTA group, n=21) were used as pulp capping agents, respectively. The patients were recalled after one year and two years. The clinical efficacy, dentin bridge index (DBI) and pulp calcification index (PCI) were recorded. Blinding method was used for the patients and evaluators. RESULTS: There was no significant difference in gender, mean age, dentition and tooth position between the two groups (P>0.05). Seven cases were lost during the first year (4 cases in iRoot group and 3 cases in MTA group). In the iRoot group, 1 case had transient sensitivity at the time of 1-year follow-up. The cure rate of the two groups was 100% at the time of 2-year follow-up. The proportion of dentin bridge formation was 38.9% one year after operation, 55.6% two years after operation. The proportion of partial or even complete disappearance of root canal image was 5.6% before operation, 38.9% and 55.6% one and two years after operation, respectively. The difference was statistically significant by rank sum test (P < 0.05). There was no significant difference in dentin bridge formation and pulp calcification between the two groups (P < 0.05). DBI and PCI after operation was as the same as those before operation (44.4% cases of DBI and 25% cases of PCI) or gradually increased (55.6% cases of DBI and 75% cases of PCI). Spearman's nonparametric correlation analysis showed that age was positively correlated with preoperative pulp calcification index (PCI0, P < 0.05), but not with the dentin bridge index (DBI1, DBI2), pulp calcification index (PCI1, PCI2) and the degree of change (DBI2 vs. DBI1, PCI1 vs. PCI0, PCI2 vs. PCI0) 1-year and 2-year after operation (P>0.05). CONCLUSION According to this study, good clinical effects were obtained within 2-year after pulpotomy of adult permanent teeth with MTA and iRoot. In some cases, the root canal system had a tendency of calcification aggravation, and there was no statistical difference in the development of this trend between the two groups.
Humans ; Adult ; Pulpotomy/methods* ; X-Rays ; Calcium Compounds/therapeutic use* ; Dentition, Permanent ; Molar/surgery* ; Treatment Outcome ; Silicates/therapeutic use* ; Aluminum Compounds/therapeutic use* ; Oxides ; Drug Combinations ; Dental Pulp Capping

OBJECTIVES: This study aimed to establish a new treatment of the mandibular second molars with external root resorption caused by impacted teeth to preserve the affected teeth and their vital pulps. METHODS: For mandibular second molars clinically diagnosed as external root resorption caused by impacted teeth, debridement and removal of the root at the resorption site via micro-apical surgery and direct capping of the pulp with bioactive material on the surface of the root amputation via vital pulp therapy were performed immediately after the impacted teeth were extracted. RESULTS: The external root resorption of the affected tooth was ceased. It was asymptomatic with intact crown, normal pulp, periapical alveolar bone reconstruction, normal periodontal ligament, continuous bone sclerosis, and no periapical translucency in radiographic examination at the 1-year postoperative follow-up, thus showing good prognosis. CONCLUSIONS Simultaneous combination of micro-apical surgery and vital pulp therapy after extraction of impacted teeth could successfully preserve mandibular second molars with ERR caused by impacted teeth and their vital pulps.
Humans ; Tooth, Impacted/surgery* ; Molar ; Mandible ; Dental Pulp ; Root Canal Therapy ; Root Resorption/etiology* ; Tooth Extraction

When the use of root canal retreatment and apical surgery experiences difficulty in treating endodontic diseases, intentional replantation is an optional clinical technique used to retain the tooth. A 28-year-old female complained of chewing discomfort at the mandibular second molar after undergoing root canal treatment 3 month ago. History record and radiographic examination revealed that a C-shaped root canal system was filled with gutta-percha in the mandibular second molar. A radiolucency area existed at the root furcal area with a thin canal wall in the distal and mesial roots. Intentional replantation was used to treat this tooth. The clinical and radiographic results showed that intentional replantation and nano-biomaterial application facilitated infection control, tooth retention, and periodontal tissue regeneration.
Female ; Humans ; Adult ; Tooth Replantation ; Root Canal Therapy ; Dental Pulp Cavity ; Gutta-Percha/therapeutic use* ; Tooth Root ; Molar/surgery* ; Retreatment

Objective: To evaluate the effect of the application of a self-developed three-dimensional visualized model of impacted tooth for surgical extraction in undergraduate oral experimental teaching. Methods: Forty-one undergraduates majoring stomatology of Tongji University from 2018 [19 males and 22 females, aged (22.4±0.8) years] were enrolled and randomly divided into the conventional group and the experimental group. Students of the conventional group (21 students including 8 males and 13 females) received a teaching protocol for the surgical extraction of impacted tooth including theoretical lectures, watching operation videos, and operating on head-simulator teaching systems. Students of the experimental group (20 students including 11 males and 9 females) received an additional training of resistance assessment and surgical extraction using the three-dimensional visualized model of impacted tooth before operating on the head simulators. After class, a questionnaire survey was carried out among students, and the operation results on the head simulators were evaluated by the teacher. Results: The results of the questionnaire showed that the students in the experimental group were rated higher than those in the traditional group in terms of being able to imagine the relationship between impacted teeth and adjacent structures (U=114.00, P=0.006), avoiding damage to adjacent teeth (U=87.00, P<0.001) and inferior alveolar nerve during tooth extraction (U=111.50, P=0.006), and being more confident in clinical operations in the future (U=120.00, P=0.013). According to the evaluation results of tooth extraction on the head simulators, there was no significant difference in the operation time between the two groups (U=138.50, P=0.056). In the experimental group, 5% (1/20) caused adjacent tooth loosening and 15% (3/20) caused the excessive bone defect, which was less than those in the traditional group [38% (8/21) and 48% (10/21), respectively] (P=0.021; P=0.043). There was no significant difference in the incidence of grinding out the deep bone of impacted teeth between the two groups (P=0.232). Conclusions: The application of three-dimensional visualized model of impacted tooth for surgical extraction in undergraduate oral experimental teaching had achieved good results and was worth popularizing.
Female ; Humans ; Male ; Molar, Third/surgery* ; Operative Time ; Students ; Tooth Extraction/methods* ; Tooth, Impacted/surgery*

OBJECTIVE: To evaluate the efficacy of iRoot BP Plus, a novel bioceramic material, and mineral trioxide aggregate (MTA) by comparing the clinical and radiographic results of pulpotomy in human primary molars, and to find out the influence factor. METHODS: Children who had at least one primary molar diagnosed as pulpitis, and received pulpotomy in the Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology from January, 2017 to December, 2018 were searched by the selection criteria in the Electronic Medical Record Database of Peking University School and Hospital of Stomatology. The molars with the pulp capping agents were iRoot BP Plus or MTA were included, and the molars with other pulp capping agents were excluded. Molars using iRoot BP Plus were selected into the experimental group (iRoot BP Plus group). Molars using MTA were selected into the control group (MTA group) using propensity score matching model (1 ∶ 1), considering the gender, age, tooth position, the title of clinician, pulp status, restoration and length of follow-up as the potential influence factor. Basic information, the relevant medical records including symptoms, clinical and radiographic examination before and after operation, intraoperative information and follow up examination records were collected. The success rates were compared and the influence factors were analyzed respectively. RESULTS: The study included 132 children, 178 molars (89 molars from each group) and the mean follow-up time was (462±99) days by December, 2019. In the iRoot BP Plus group, 9 molars failed whilst 6 molars failed in MTA group. The success rate was 89.9% and 93.3%, respectively, showing no significant difference between the two groups. Through Cox proportional risk model analysis, the success rate of iRoot BP Plus was significantly lower when the pulp status was poor, while other factors including age, tooth position, title of clinician and restoration were not found to be associated with the clinical outcome. CONCLUSION Pulpotomy of human primary molars with iRoot BP Plus has the same effectiveness with MTA. The pulp status is the main factor that influences the outcome of iRoot BP Plus. Further studies with larger sample sizes and longer follow-up terms are needed.
Child ; Humans ; Pulpotomy/methods* ; Pulp Capping and Pulpectomy Agents ; Pemetrexed ; Silicates/therapeutic use* ; Aluminum Compounds/therapeutic use* ; Calcium Compounds ; Oxides ; Molar/surgery* ; Drug Combinations ; Treatment Outcome ; Tooth, Deciduous