Purpose: To investigate the effect of digital scanning combined with reverse engineering technology in the demonstration of full-crown tooth preparation. Materials and Methods: A total of 31 students were randomly divided into two groups. The students in the control group conducted traditional demonstration using eye-measurement methods. The students in the experimental group carried out improved demonstration using digital intraoral scans with 3D-measurement data. The students in both groups were provided with two resin teeth to conduct full-crown tooth preparation on head model dental simulators. The teeth prepared before and after demonstration were scored according to Chinese Stomatological Association Group Standards with a total score of 100 points. Analysis of covariance (ANCOVA) was performed to comparatively analyze the scores related to the tooth surfaces and the convergence angle between the two groups. Results: Analysis of two prepared teeth (a maxillary right central incisor and first molar) in two groups showed that there was a statistically significant difference in the mean score between the control group and experimental group (central incisor, P = .0039; first molar, P = .0120). The demonstration of the first molar showed that there were statistically significant differences in the scores related to the buccolingual surface (P = .0205) and proximal surface (P = .0023) between the control group and experimental group. There was a statistically significant difference in the score related to the convergence angle of the buccolingual surface between the control group and experimental group (P = .0265). Conclusions: The digital method can effectively improve the quality of tooth preparations and has a pedagogic advantage for posterior teeth, which present greater operational challenges. IntJ Prosthodont2025;38:257-263. doi: 10.11607/ijp.8968

AIM or PURPOSE To evaluate which water supply method could effectively reduce the contamination of dental unit waterlines (DUWLs). MATERIALS and METHOD The main of water sources of DUWLs are closed bottled water with three solutions (distilled water, chlorine-containing solution and multi-enzyme cleaning solution) and an ozone generator for 7 consecutive days. The water samples are collected from the three-way syringe (TWS), high-speed drill (HSD), and mouthwash water supply device (MWSD). The final water samples’ dilution was spread on a nutrient agar medium plate and incubated for 48 hours at 37°C by calculating the concentration of microorganisms (CoF) using colony-forming units per milliliter (CFU/mL) to measure the quality (China national standard GB/T 5750.12-2006, 100 CFU/ml). Complete data was analyzed by generalized estimating equations (GEE), and missing data was filled by mean imputation. RESULTS The CoF of water samples from TWS, HSD, and MWSD was 46.50 CFU / mL, 14.13 CFU / mL, and 14.63 CFU / mL on the last day, respectively. The results of GEE show that for the CoF, there were statistically significant differences between water samples of chlorine-containing solution compared to water samples of distilled water in TWS (P < 0.0001) and MWSD (P < 0.0001), and the statistically significant differences were also found between the water samples of ozone generator compared to the water samples of distilled water in HSD (P < 0.0001). Other quality of water samples didn't meet the China national standard. CONCLUSION(S) The finding revealed that chlorine-containing solution and ozone generator could reduce the bacteria compared with distilled water in DUWLs.

Objectives Vitamin consumption and caries are related, although not much research has looked at the two together. This study examined the connection between the total number of decayed teeth (Decay, D) and vitamin intake using data from the National Health and Nutrition Examination Survey (NHANES) database. Methods NHANES (2011–2018) provided the data for this retrospective analysis. Dental examiners, who were licensed dentists in at least one U.S. state, defined the number of caries-ridden teeth using the Radike AW Criteria for Diagnosis of Caries (1968), whereas the vitamin consumption data came from in-person interviews. To investigate the link between the total number of decayed teeth (D) and vitamin, multiple linear regression analysis was done. The quantitative data was described by mean ± standard deviation, whereas the categorical data was described by number of instances and proportion [n (%)]. Results Results: This retrospective study comprised 3226 people in total. Approximately 579955.26 mg (579955.26/3226/30 = 5.99 mg/day/person) of vitamin C was the most consumed throughout the course of 30 days, making up 88.72% of the total amount of vitamin nutrients consumed. The total number of decayed teeth (D) was influenced by age (years) (β = 0.0125, P = 0.0281), PIR (β = 0.3348, P < 0.0001), BMI (β = -0.0299, P < 0.0391), gender (β = 0.5127, P = 0.0063), race (β = -0. 8265, P < 0.0001), education (β = 0.9201, P = 0.0013), vitamin B6 (β = 0.0112, P = 0.0076), vitamin C (β = 0.0005, P = 0.0370), and vitamin D (β = -0.0080, P = 0.0001), with BMI, race, and vitamin D exhibiting a negative correlation. Conclusions There is a correlation between vitamin intake and carie. Caries is more common when there is an excess of vitamin C, insufficient vitamin D, and excessive vitamin B6. Naturally, additional prospective clinical trials are required to confirm our findings and investigate potential causes.

Stomatology medical equipment is an indispensable tool in stomatology diagnosis and treatment work,and achieving efficient management of stomatology medical equipment can help improve the quality and efficiency of clinical diagnosis and treatment work.Due to the wide variety of stomatology medical equipment and complex maintenance and repair types,equipment management is difficult.How to achieve unified and efficient management of equipment is a challenge for equipment management personnel.Based on the current situation of stomatology medical equipment management and the work needs of management personnel,this paper designs and develops a stomatology medical equipment management system using LabVIEW software and Microsoft Office Access database.The stomatology medical equipment management system has achieved safe,efficient and refined management of stomatology medical equipment.Through the system operation,the information management and statistical efficiency of stomatology medical equipment have been improved,which helps to improve equipment usage efficiency and provides reliable solutions for stomatology equipment management.

Objectives The objective of this study is to develop a deep learning (DL) model for fast and accurate mandibular canal (MC) segmentation on cone beam computed tomography (CBCT). Methods A total of 220 CBCT scans from dentate subjects needing oral surgery were used in this study. The segmentation ground truth is annotated and reviewed by two senior dentists. All patients were randomly splitted into a training dataset (n = 132), a validation dataset (n = 44) and a test dataset (n = 44). We proposed a two-stage 3D-UNet based segmentation framework for automated MC segmentation on CBCT. The Dice Similarity Coefficient (DSC) and 95% Hausdorff Distance (95% HD) were used as the evaluation metrics for the segmentation model. Results The two-stage 3D-UNet model successfully segmented the MC on CBCT images. In the test dataset, the mean DSC was 0.875 ± 0.045 and the mean 95% HD was 0.442 ± 0.379. Conclusions This automatic DL method might aid in the detection of MC and assist dental practitioners to set up treatment plans for oral surgery evolved MC.

Objective:To investigate the effect of different ventilation schemes on the concentration of aerosol pollutants in independent space during dental diagnosis and treatment.Methods:Independent dental treatment room equipped with ventilation systems and air disinfectors was selected. A total of nine working conditions including three different dental treatments (supragingival scaling, root canal preparation and tooth preparation) were carried out respectively in three different ventilation schemes (natural ventilation, dedicated outdoor air system and dedicated outdoor air system combined with air disinfector) . The aerobic bacterial counts were measured at different heights and time points. Spatiotemporal distributions of aerosol pollutants in different ventilation schemes were analyzed quantitatively. The differences and equilibrium states of aerobic bacterial counts were examined using Spearman′s rank correlation analysis, generalized linear mixed models, analysis of variance (ANOVA) , Wilcoxon rank sum tests, and multiple comparisons following rank order transformation.Results:The results of the ANOVA test revealed no statistically significant variations in the aerobic bacterial counts at each site (F = 1.45, P = 0.182) , indicating that the aerobic bacterial counts were spread uniformly across sites. Compared to natural ventilation, the aerobic bacterial counts (Nworking condition1 = 25.8 CFU/cm2; Nworking condition2 = 10.4 CFU/cm2; Nworking condition7 = 35.7 CFU/cm2; Nworking condition8 = 6.5 CFU/cm2) under dedicated outdoor air system during supragingival scaling and tooth preparation decreased over time (tsupragingival scaling = 2.27, Psupragingival scaling = 0.024; ttooth preparation = 2.30, Ptooth preparation = 0.022) . There is no significant difference between aerobic bacterial counts of the treatment after 30 minutes to 60 minutes and that after 60 minutes to 120 minutes, indicating the dynamic equilibrium of bacterial accounts was reached at 30 minutes after the spraying treatment, which met the class Ⅳ environmental requirements in the Hygienic Standard for Disinfection in Hospitals GB 15982-2012.Conclusions:It can effectively reduce aerosol pollutants in a specific space in a certain period of time under the dedicated outdoor air system. The risk of the next patient can be greatly reduced when entering the dental treatment room at 30 minutes after the previous treatment.

Objective To explore the feasibility of applying the Malocclusion Impact Questionnaire (MIQ) of Chinese version among Chinese teenagers, through the verification and evaluation of the Chinese version. Methods According to the standard procedures of the international quality of life assessment program, the MIQ was translated, back translated, adapted and updated culturally, and the Chinese version was established. The 161 teenagers with the first orthodontic treatment were included. This patient group was assessed for oral health-related quality of life by the Chinese version of the MIQ and Children's Perception Questionnaire (11-14 years old). The reliability and validity of the Chinese version of the MIQ were evaluated statistically by Spearman and factor analysis. Results A total of 161 valid questionnaires were collected. The internal consistency Cronbach's α of the Chinese scale was 0.887. The correlation coefficient between items and the scale ranged from 0.000 1 to 0.824. A significant positive correlation of the scores was noted between the translated scale and the Children's Perception Questionnaire (11-14 years old), and the correlation coefficient was 0.444 (P<0.001). Conclusion The reliability and validity of the Chinese version of the MIQ are reliable and can be applied for clinical orthodontic treatment.

目的:使用Simodont虚拟仿真口腔培训系统对不同年级口腔学生手部灵巧度进行训练并对结果进行定量评估，探讨该系统的应用价值。方法:汕头大学医学院口腔医学系2015至2018级共118名学生进行统一培训后，每位学生给予5个不同的手部灵巧度练习模块进行练习，每个模块有3个难度进阶，每个模块要求30 min内完成。系统自动记录每个学生的操作成绩，包括规定磨除量、底壁和侧壁磨除偏移量及误磨量，均以体积百分比为单位；同时评估操作时间（以秒为单位）、操作过程中口腔用手机位移和口镜位移（以米为单位）。应用SPSS 25.0软件进行统计分析。结果:对于规定磨除量、底壁和侧壁磨除偏移量及误磨量，系统评估结果显示：已经经过专业课学习和仿真头模等临床前培训的学生（四年级学生）和未进入专业课学习、未经过培训的学生（一到三年级学生）之间差异具有统计学意义（ P<0.001）。对于规定磨除量的完成情况，5个练习模块均能体现年级间差异性并具有统计学意义（ P<0.001）。 结论:Simodont虚拟仿真口腔培训系统中圈形模块、隧道模块、甜甜圈模块和十字交叉模块具有对不同层次口腔医学学生手部灵巧度能力评估的敏感性，立体边缘模块对手部灵巧度能力评估的敏感性则需要通过进一步的评估。Simodont虚拟仿真口腔培训系统对手部灵巧度训练结果（如规定磨除量、底壁和侧壁偏移情况等）可进行定量评估，对口腔临床前教育的评价具有重要意义。

<span id="ChDivSummary" name="ChDivSummary" class="abstract-text">目的:探讨口腔专科医疗机构信息平台一体化的建设及实践应用。方法:通过分析口腔专科医疗信息平台架构需求,同时考虑平台服务能力及数据的安全性,汕头大学医学院口腔医院门诊部信息平台建设项目以私有云建设及"互联网+"为基础部署数据平台。结果:汕头大学医学院口腔医院门诊部信息平台以结构化的电子病历作为信息输入主线,融合患者信息管理、电子义齿技加工管理、院感管理及器械追溯管理、物资采购、财务绩效等模块,形成高度集成的一体化信息系统。结论:该平台有利于口腔专科医疗机构对以临床信息为主体的多方信息的综合处理和深度挖掘,提高医院综合管理水平,推动医院基础管理工作,合理配置医疗资源,改善患者就医体验。</span>

This study aimed to investigate the relationships among sicca symptoms, oral health conditions, salivary profiles and oral Candida in Sjögren's syndrome (SS) patients. Eighty-five SS patients (mean age = 50.5) and 40 healthy non-SS individuals (mean age = 51.4) were recruited. They self-completed the Sicca Symptoms Inventory (SSI). Decayed, missing and filled surface (DMFS) scores, salivary flow rates, pH and oral Candida colonization were determined. Mean SSI summary scores of SS patients and non-SS individuals were 11.1 and 5.4 respectively (p < 0.001). The most prevalent sicca symptoms in SS patients were eye irritation (93%), dry throat or nose (88%) and need of fluid for mouth wetting (88%). SS patients had significantly lower whole salivary flow rates than the non-SS individuals. Candida strains were isolated from over 60% of SS patients but not in non-SS patients. C. albicans was the predominant species. SSI summary score was negatively correlated to salivary flow rates while SSI summary and domain scores were positively correlated to the number of filled surfaces (FS) and DMFS scores and oral Candida counts. In conclusion, SS patients had more severe sicca symptoms than non-SS individuals. SSI scores were negatively correlated to the salivary flow rates but positively correlated to caries experience and oral Candida colonization.

Objective To assess postoperative pain after endodontic therapy and its association with clinical factors such as gender, age, tooth type, pulpal diagnosis, and preoperative pain, length of obturation and sealer extrusion. Methods The patients, who came to the Clinic of Stomatology, SUMC and received the root canal therapy for molars and premolars from July, 2018 to April, 2019, were randomly selected by simple random sampling (the order of subjects′ recruitment) . There were 140 cases, including 63 males and 77 females. Local Anesthesia (2% Lidocain with 1∶80 000 Epinephrine) was administered. Access cavity was prepared with the help of bur. Canal preparation was completed using standard technique. Access was sealed with sterile dry cotton pellet and restored temporarily with double layer of glass ionomer cement. After one week patients were recalled and access was re-opened, obturation was done using continuous-wave of gutta-percha vertical condensation technique. AH-plus sealer was used. Postoperative radiographs were taken. Patients were recalled after 24 hours and postobturation pain was recorded using visual analogue scale (VAS) . Data was recorded and χ2 test and Logistic regression was used for statistical analysis. Results A total of 140 cases were included and 84 patients (60%) developed postoperative discomfort. 61 patients (43.6%) reported mild. 9 (6.4%) and 14 (10%) presented moderate and severe pain, respectively. No patients had extremely severe pain. The χ2 test showed that postoperative pain was independent of gender and tooth type but correlated with the diagnosis of preoperative pulp infection (χ2 = 76.11, P<0.001) and obturation (χ2 = 16.3, P<0.001) , as well as the presence of sealer extrusion apical orifice. Multivariate Logistic regression analysis showed that no symptoms before operation and postoperative pain was correspondingly reduced (OR = 0.179, P = 0.048) . If the paste was not exceeded, the incidence of postoperative pain was reduced (OR = 0.039, P = 0.005) . Chronic pulpitis had less postoperative pain than periapical inflammation (OR = 0.034, P<0.001) , while pulp necrosis had more postoperative pain than periapical inflammation (OR = 4.080, P = 0.038) . Compared with overfilling, both adequate filling (OR<0.001, P<0.001) and underfilling<2 mm from the root tip (OR<0.001, P<0.001) reduced postoperative pain. Conclusions A significant association of obturation with postoperative pain was observed in this study. Therefore, clinician should avoid the sealer extrusion when doing the obturation. For the patients with pulp neurosis and periapical lesions, communication after root canal treatment should be pay more attention to. Key words: Root canal therapy; Pain, postoperative; Visual analog scales; Clinical trials

For displaying the three-dimensional ( 3D ) digital model of teeth , we constructed a digital learning platform of "oral anatomy and physiology-tooth morphology" based on the WeChat small program of smart phones integrating teaching resources like texts , pictures , videos , three-dimensional animation and others. The textual content of tooth morphology was edited according to the Chinese textbook Oral Anatomy and Physiology (seventh edition) of the People's Health Publishing House and Wheeler's Dental Anatomy, Physiology and Occlusion. After photographing and cone beam CT scanning the tooth in vitro, JPEG file of tooth contour and DICOM file of tooth cross section were obtained. Continuous tomographic dynamic pictures of the tooth and 3D videos was presented by adopting software of Photoshop CS6, CS 3D imaging (affiliated simple software of cone beam CT), Snagit, Video Editor and Aijianji. Following steps of WeChat official website to register, develop, compose code, upgrade pictures and texts, submit to be verified and release, small program "Dental Anatomy Learning Platform" was completed and put into use. According to the survey, 90.3％(93) users believed the small program is helpful to learn Oral Anatomy and Physiology, especially in deepening the understanding of the tooth morphology and structure;96.1％( 99 ) users considered that the small program can be added to the classroom as a supplement, but it can't replace the textbook totally . The development of "Dental Anatomy Learning Platform" will provide methodological guidance for the development and integration of various dental teaching resources on the internet.

Background: Sjögren’s syndrome (SS) patients are prone to caries development due to reduction of salivary flow. Topical fluoride is commonly prescribed for caries prevention. Methods: In this 24-month randomized, double-blind, placebo-controlled clinical trial, SS patients were randomly assigned to receive either fluoride varnish or placebo gel quarterly. Development and arrest of caries at the coronal and root surfaces were recorded at 12-month and 24-month and compared to that of the baseline. Effect of fluoride varnish on oral Candida and lactobacilli colonization was explored by comparing baseline oral microbiological assessments to data obtained at 12-month and 24-month. Results: Seventy-eight SS patients (mean age = 50 years, 2 men) completed this trial. At 24-month, the mean new coronal enamel caries were 1.6 surfaces in both groups, and new dentin caries were 1.4 and 2.7 surfaces in the fluoride and placebo group respectively (p > 0.05). Mean arrested caries were 0.6 and 0.7 surfaces for fluoride and placebo groups respectively and that of root caries were 0.3 and 0.1 surfaces (p > 0.05). The mean oral Candida count was reduced by 30% in the fluoride group but increased 61% in the placebo group while no change in oral lactobacilli counts in both groups at 24 months (p > 0.05). SS patients receiving fluoride varnish were significantly less likely to develop dentin caries (p < 0.05). In contrast, those with high baseline DMFS scores (p = 0.05), harbored mixed Candida species (p < 0.05), or unstimulated whole saliva at low pH (p < 0.01) were significantly more likely to develop dentin caries. Conclusions: Results of this randomized clinical trial did not provide clear evidence to support or refute that quarterly applications of fluoride varnish can prevent development of dental caries in people with Sjögren’s syndrome. Trial registration: This study was retrospectively registered at the ISRCTN registry (ISRCTN85164658) on 9 Sept 2016 and was funded by the Research Grant Council of Hong Kong.

Objective To explore the relationship betweenrheumatoid arthritis (RA) and chronic periodontitis (CP). Methods A total of 48 RA patients were recruited from the Rhematology Department of The First Affiliated Hospital of Shantou University Medical College (SUMC). RA patients were matched on age and gender with healthy controls, who were recruited from the Stomatology Department. Dental parameters including unstimulated salivary flow rate(UWS), stimulated salivary flow rate (SWS), bleeding on probe (BOP), periodontal probing pocket (PD), clinical attachment level (CAL) and decayed, missing and filling (DMF) were recorded in all cases. Erythrocyte sedimentation rate (ESR), C-reac-tive protein (CRP) and Anticyclic citrullinated peptide antibody (Anti-CCP) were also recorded in RA patients. Results There were significant difference between RA group and health control group on salivary flow rate, BOP, PD, CAL and DMF (P<0.001). Higher percentage of RA patients were diagnosed as periodontal disease than those in con-trol group (P<0.001). There was relationship between CAL and Anti-CCP antibody (P<0.001). Conclusion RA pa-tients have higher risk of CP, and there might be relationship between RA and CP.

目的:搭建基于智能移动终端的远程牙科全英教学数字化电子书,该电子书包括主要授课的文案PPT、视频以及参考文献,同时有互动教学及延伸阅读板块,最大程度利用整合各类教学资源.方法:参照人民卫生出版社的《口腔科学》及《Oxford Handbook of Clinical Dentistry》,进行内容架构的编排,同时通过搜索相关内容的视频和图片,采用iBooks Author进行内容编排,完成电子书制作.结果:完成电子书的制作,采用iBooks格式,学生可自由下载进行阅读,包括视频和图片的观看.结论:基于智能移动终端的远程口腔科学全英教学数字化电子书在教学上解决全英教材缺乏问题以及课时限制问题,学生可在课外进行阅读浏览,同时也可作为临床医生对口腔疾病查阅的电子工具书.

Objective To assess the therapeutic effect of fluoride varnish Duraphat on the performance of incipient carious lesions white spot lesions (WSL) in anterior teeth in vivo. Methods The sample included 120 children aged 7 to 13 years old , with a total of 146 active WSL in permanent anterior teeth. The children were randomly divided into 3 groups, according to the treatment received:Group A (fluoride varnish Duraphat+oral health instrument, n=52), Group B (oral health instrument, n=47) and Group C (control, n=47). Maximum WSL dimensions (mesiodistal and incisogingival) were measured in millimeters by a previously calibrated single examiner using a periodontal probe . The oral hygiene was assessed by the plaque index . Results Wilcoxon test revealed a statistically significant difference (χ2=29.1,P<0.001) between the initial size and final size in A group (1.53 vs. 0.88) and B group (1.56 vs. 1.47). Pearson′s chi-square test revealed statistically significant differences (χ2=42.5, P<0.001) in the caries activity of the WSL among three groups. Conclusions The fluoride varnish Duraphat is effective to the incipient carious lesions in permanent anterior teeth .

目的:通过应用<口腔健康影响程度量表(OHIP-14中文版)>(以下简称<程度量表>测评慢性牙周炎对患者口腔健康相关生存质量的影响.方法:使用<程度量表>对中山大学附属口腔医院牙周科符合纳入/排除标准的102名患者进行调查,患者同时填写<口腔健康自我评价表>记录个体基本情况和自觉症状,并进行牙周检查:牙周炎程度(轻、中、重度)、缺失牙数及探诊深度＞5mm的牙数.结果:102例慢性牙周炎患者的<程度量表>平均得分为14.72±7.29,普通人群(550个体)的平均得分为11.84±9.88,(Z=-4.15,P<0.05).经历过"牙龈退缩(P<0.05)"、"牙齿疼痛(P<0.05)"、"牙齿松动(P<0.05)"的患者其生存质量低于无经历过此类症状的患者.量表总得分与患者牙周炎的严重程度具相关性(rs＝0.209,P<0.05),与探诊深度＞5 mm牙数的多少不具相关性(P>0.05).结论:慢性牙周炎患者总体口腔健康相关生存质量低于牙周健康人群.

Objective:To compare the performance of the Chinese versions of GOHAI and OHIP-14as measurements of the oral health related quality of life of the elderly population.Methods:Data were collected by means of a personal interview.All participants were aged 60years and above and able to give informed consent,excluding those with cognitive impairment.A questionnaire which the participants completed contained the Chinese version of GOHAI and OHIP-14with a list of questions concerning self-perceived oral health,tooth status.Clinical examination was performed to record the number of missing teeth,the type of the denture,etc.The ability of the two measures to detect oral health related quality of life outcomes was assessed by examining responses to individual items and by the analysis of dimensions,tests of discriminant and the internal consistency reliability.Results:A total of 250adults were surveyed.There were 221valid questionnaires involving 12with missing data.The mean score of the Chinese version of GOHAI was higher than the one of the OHIP-14(P0.01).Both measures could discriminate between dentulous participants according to the number of missing teeth.Furthermore,dentulous participants wearing one or more dentures had higher scores on both measures than dentulous participants who did not wear a denture.Scores were also higher on both measures for those rating their oral health as only fair or poor and those dissatisfied with their tooth status.Conclusion:Chinese version of GOHAI and OHIP-14in terms of detecting oral health related quality of life outcomes in this elderly population,is almort the same.