中华口腔医学杂志最新文献

Early enamel demineralization, one of the common side effects of orthodontic treatment, occurs when dental plaque accumulation disrupts the balances of demineralization-remineralization and the oral microbial ecology. Clinically, the existence of orthodontic appliances can make oral hygiene more challenging. At the same time, patient adherence to oral hygiene appointments may be inconsistent. The combination of these factors often leads to inadequate plaque control and increases the risk of enamel demineralization. Presently, there is a lack of standardized guidelines for the clinical intervention and management for early enamel demineralization. Moreover, the associated risk assessment and prevention systems require further improvement. This article provides a review of the etiology, risk factors, and preventive and treatment strategies for managing early enamel demineralization in orthodontic patients. The aim is to provide references for clinicians to promote the early detection, early intervention, and standardized management of early enamel demineralization, thereby effectively controlling the incidence and progression of these lesions during orthodontic treatment.

Cone beam CT (CBCT) has been widely used in endodontics in recent years. To promote the rational and effective application of CBCT in endodontics, this article introduces the principle of "As low as diagnostically acceptable being indication-oriented and patient-specific (ALADAIP)" for radiographic examination in endodontics. It summarizes and discusses key points of CBCT images evaluation in root canal anatomical variations, dens invaginatus, pulp calcification, odontogenic maxillary sinusitis, root fractures, periapical lesions, and post-endodontic treatment pain. Additionally, it explores how to dialectically use CBCT in evaluating root canal anatomical variations, pulp calcification and cracked tooth, and finally gives some tips about the scanning and three-dimensional reconstruction of CBCT in endodontics.

The proximity of maxillary posterior teeth roots to the maxillary sinus, and the greater distance between the palatal root and the buccal bone wall are factors constituting the key challenges in apical surgery for maxillary posterior teeth. Particularly, the surgical treatment of maxillary posterior tooth roots located within the maxillary sinus poses an even higher technical difficulty. Focusing on the interrelationship between the maxillary sinus and maxillary posterior teeth, this paper analyzes and discusses the pre-operative evaluation elements involved in maxillary sinus-related endodontic microsurgery as well as the operational key points during the surgical procedure, based on clinical research findings and the team's experience. Additionally, it introduces the management of concurrent complications, post-operative care, and efficacy evaluation, aiming to provide guidance for clinicians in performing such microscopic apical surgeries.

Objective: To analyze and compare the sealing ability of three bioceramic root canal sealers (iRoot SP, cRoot SP, nRoot SP) in root canal obturation using the single-cone technique by means of micro-CT. Methods: Single-rooted premolars freshly extracted from patients aged 14-24 years for orthodontic reasons at the Department of Oral and Maxillofacial Surgery, Shanghai Stomatological Hospital were collected. Thirty extracted teeth were strictly included according to the five inclusion criteria to ensure baseline consistency of the experiment and randomly divided into three groups (n=10) by lottery. The root canals were prepared using the ONE-PLEX single-file system. The three groups of extracted teeth were then obturated using the single-cone technique with iRoot SP, cRoot SP, and nRoot SP sealers, respectively. The obturated specimens were stored in a 100% humidity environment at 37 ℃ for 14 days to allow complete setting. Subsequently, the specimens were scanned using micro-CT. Three-dimensional reconstruction of the root canal system was performed using CTAn software. The void volume within the root canal was measured in the apical third (2-3 mm from the root apex), middle third (>3-5 mm from the root apex), and coronal third (>5-7 mm from the root apex), respectively. The root canal filling void percentage was calculated. Data regarding the total void percentage, interfacial gap percentage, and siolated void percentage in the apical, middle, and coronal thirds of the obturated specimens from the three groups were analyzed using analysis of variance or non-parametric tests with SPSS software. The significance level was set at P<0.05. Results: In the iRoot SP group, cRoot SP group, and nRoot SP group, the total void percentage after obturation showed no statistically significant differences in the apical segment [(16.81±3.15)%, (15.21±3.62)%, (13.52±2.90)%], the middle segment [(14.52±4.21)%, (12.66±2.37)%, (11.63±2.39)%], or the coronal segment [(11.96±5.31)%, (12.59±4.98)%, (10.09±1.77)%], respectively (P=0.093, P=0.129, P=0.417). No statistically significant differences were observed in the interfacial gap percentage among the groups in the apical segment, middle segment, or coronal segment after obturation (P=0.112, P=0.147, P=0.463). Similarly, no statistically significant differences were found in the isolated void percentage among the groups in the apical segment, middle segment, or coronal segment after obturation (P=0.388, P=0.810, P=0.584). Conclusions: Based on quantitative analysis of root filling void volume using micro-CT scanning, the short-term sealing abilities of the novel bioceramic root canal materials cRoot SP and nRoot SP in standardized root canals are comparable to that of the classical bioceramic sealer iRoot SP in vitro.

Proposed in the early 20th century, the focal infection theory hypothesizes that teeth with dental caries, endodontic-periapical/periodontal diseases, plus impacted teeth and residual roots, might act as infection foci, inducing pathologies in distant organs including respiratory tract, gastrointestinal tract and brain, etc. During the prevalence of this theory, tooth extraction was well received as a key adjuvant therapy for systemic diseases, profoundly influencing paradigms of dentistry and clinical medicine. In the mid-20th century, advances in evidence-based medicine and diagnostic/therapeutic techniques led to the demise of focal infection theory. Tooth extraction ceased to be a major systemic disease intervention, while conservative dentistry as represented by root canal therapy progressed substantially. Since the proposal of "periodontal medicine" in the 1990s, the link between oral infectious diseases and systemic diseases has regained attention from dental and medical professionals. Recent progress in oral-systemic comorbidity animal models and high-throughput multi-omics has increasingly elucidated mechanisms by which oral infections exacerbate/induce systemic diseases. This article comprehensively reviews the historical evolution and impacts of focal infection theory on dental medicine (especially endodontics), offering references for future researches.

Bone metabolism is a highly ordered biological process that relies on the dynamic balance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption to maintain the normal structure and function of bone tissue. Reactive oxygen species (ROS), as an important product of intracellular redox reactions, participates in the regulation of key physiological processes such as cell signal transduction and gene expression at physiological concentrations. However, when the generation and clearance of ROS are imbalanced, excessive ROS will trigger oxidative stress, leading to damage of intracellular biomacromolecules (such as lipids, proteins, and DNA), and thus disrupting tissue homeostasis. In recent years, an increasing number of studies have revealed that ROS plays a central role in the regulation of bone metabolism. Pathologically elevated ROS levels can disrupt the homeostasis of bone metabolism. This imbalance in homeostasis is a key pathogenic factor in the development of various oral hard-tissue diseases such as periodontitis and peri-implantitis. This article systematically reviews the molecular mechanisms by which ROS regulates bone metabolism and its significance in oral bone-related diseases, aiming to provide a theoretical basis and new research directions for the prevention and treatment strategies of related diseases.

Objective: To evaluate the accuracy and efficiency of an autonomous dental robotic system in performing calcified canal localization and negotiation on standardized three-dimensional (3D)-printed jaw models. Methods: Two pairs of standardized 3D-printed maxillary and mandibular models, containing a total of 56 teeth, 92 calcified root canals, were used. Virtual access paths were planned based on preoperative cone beam CT (CBCT) and intraoral scan data using digital dental design software. An experienced operator controlled the autonomous dental robotic system to perform canal localization, and drilling time were recorded. Postoperative CBCT images were registered with preoperative plans to calculate accuracy parameters, including coronal deviation, apical deviation, and angular deviation. The residual thickness of canal wall at drilling end level, and the success rate of calcified canal location was recorded as well. Multiple linear regression analysis was performed to evaluate the effects of tooth position, jaw position, operation side and calcification depth on accuracy and drilling time. Results: The coronal deviation, apical deviation, and angular deviation of the calcified canal negotiation assisted by the autonomous dental robot were 0.35 (0.21) mm, 0.47 (0.27) mm, and 1.17° (1.35°), respectively, with an average drilling time of 39.00 (25.25) s. The residual dentine thickness of canal wall at drilling end level was (1.24±0.51) mm. The success rate of calcified canal location was 95.7% (88/92). Multiple linear regression analysis revealed that jaw position had a significant effect on coronal deviation (P<0.05), while tooth position, operation only side, and calcification depth showed no significant influence on any accuracy parameters (P>0.05). Moreover, calcification depth had a significant effect on drilling time (P<0.05), whereas tooth position, jaw position, and operation side showed no significant influence (P>0.05). Conclusions: The autonomous dental robotic system demonstrated high accuracy and efficiency in calcified canal localization in vitro.

Recent studies have demonstrated that the functions of taste G protein-coupled receptor (GPCR) extend far beyond gustation. These receptors are widely distributed in oral tissues, participating in local immune regulation and maintenance of oral microbial homeostasis. As chemosensory receptors, taste GPCR modulate individual sensitivity to sweet and bitter stimuli, thereby influencing dietary preference, sugar intake, and susceptibility to dental caries. In addition, they play crucial roles in microbial signal recognition and the preservation of ecological balance within the oral cavity. Downregulation or dysfunction of these receptors may arise from intrinsic or extrinsic factors such as genetic polymorphisms, inflammatory stimuli, head and neck squamous cell carcinoma, or radio-chemotherapy. These alterations can compromise GPCR-mediated mucosal immune defenses and promote a pathological shift in microbial community composition, ultimately leading to oral dysbiosis as well as imbalanced demineralization and remineralization of dental hard tissues. This article reviews the research progress on the structure and function of sweet and bitter GPCR, and clarifies their association with dental caries from the perspective of oral ecology and microbiota regulation. Future studies focusing on structure-based receptor targeting are expected to provide a solid theoretical foundation for precise therapeutic strategies such as "taste-guided anti-inflammation" and "taste-mediated microbiota modulation" and to expand their translational prospects in clinical dentistry.