Correlation of resin composite translucency and IOS accuracy: An in-vitro study.

Background: Different restoration materials have different optical characteristics that influence the intraoral scanner's (IOS) image accuracy. The purpose of this in-vitro investigation was to investigate how composite translucency affected the accuracy of IOS. Material and Methods: GC G-aenial Universal Injectable JE composite plates were used for the study at 3 thicknesses (1-2-3mm). A lab scanner (3Shape E1) obtained 1 reference scan, whereas IOS (Trios3) was used to conduct 10 experimental scans per group. After 3D superimposition, deviation values were used to assess the accuracy (trueness and precision) outcomes for the corresponding groups. Using an LS170 V2.0 colorimeter, the translucency parameter (TP) of the plates was determined from L*a*b* values of CIELAB color space. Results: The composite translucency resulted in a decrease in the scale of digital impressions. The 1mm group had the largest scale reduction (0.02mm) significantly, followed by the 2mm and 3mm groups (0.01mm). No difference was found in mean precision. The colorimeter detects the L*a*b* values and showed that 1mm composite plate expressed the highest TP value, then 2mm and 3mm groups (28.90, 14.26 and 6.49 respectively). The thinner composite, the higher translucency and TP were highly positively correlated to IOS trueness of composite plates. Conclusions: Composite translucency has an impact on optical impression accuracy. In correlation, the optical impression becomes less accurate the more translucent the composite is. This implies that in the digital process, the dentist should specify the appropriate optical properties of composite materials concerning both their mechanical and aesthetic qualities. Key words:Accuracy, translucency, resin composite, digital dentistry, intraoral-scanner.

Temporal stability of tongue microbiota in older patients - A pilot study.

Background/purpose: Healthy states of human microbiota depend on a stable community of symbiotic microbes irrespective of external challenges from the environment. Thus, long-term stability of the oral microbiota is of importance, particularly for older patient populations. Materials and methods: We used next-generation sequencing (NGS) to examine the tongue microbiota of 18 individuals receiving long-term care over a 10-month period. Results: Beta diversity analysis demonstrated temporal stability of the tongue microbiota, as microbial compositions from all time points were indistinguishable from each other (P = 0.0887). However, significant individual variation in microbial composition (P = 0.0001) was observed, underscoring the presence of a unique microbial profile for each patient. Conclusion: The temporal dynamics of tongue microbiota exhibit long-term stability, providing diagnostic implications for oral diseases within older patient populations.

Utilization of 3D evaluation for assessing selective caries removal practice in pre-clinical dental students: a pilot study.

BACKGROUND: Practicing and assessment of selective caries removal techniques in dental students remain challenges in many dental schools. The aim of this study was to utilize a 3D assessment technique, within a designated acceptable range of deviation, to evaluate the tendency of dental students in performing selective caries removal (SCR). The correlation between 3D assessment results and the conventional rubric rated by an instructor was also determined. METHODS: Fifth-year dental students (n = 61) performed the SCR task on 3D-printed teeth containing simulated deep caries lesions in occlusal and proximal surfaces. One instructor assessed the results using a conventional analytic rubric. The excavated teeth were additionally evaluated using 3D analysis software with the designated acceptable range of deviations (± 0.5 mm) from the standard cavities. The average root mean square (RMS) value, representing the deviation between student-prepared cavities and the predefined standard cavities, was recorded. A tendency towards over-excavation was defined for RMS values > 0.5 mm, and towards under-excavation for RMS values < 0.5 mm. RESULTS: The mean (min-max) of RMS was 0.27 (0.18-0.40) for occlusal and 0.29 (0.20-0.57)for proximal cavities. A tendency of dental students toward over-excavation was observed in both occlusal (74%) and proximal cavities (87%). There was a moderate negative correlation between the RMS values and the traditional rubric scores for both occlusal (R2 = 0.148, P = 0.002) and proximal cavities (R2 = 0.107, P = 0.010). CONCLUSIONS: The 3D evaluation technique effectively revealed specific tendencies in dental students' caries removal skills. The integration of computerized assessments with traditional methods could potentially assist the instructors in delivering more objective and specific feedback to students. Further research is encouraged to investigate the impact of this assessment technique on improving student performance in selective caries removal skills.

Effectiveness of mobile augmented reality-integrated oral health education for community-dwelling older adults: A randomized controlled trial.

BACKGROUND & PURPOSE: Oral health education helps older adults optimize their oral health. However, traditional lecture-based oral health education has limitations, exacerbated by the COVID-19 pandemic. Mobile augmented reality (MAR) has emerged as an alternative educational method. This study compared the effectiveness of MAR-integrated oral health education with that of lecture-based education and no education. METHODS: This parallel, randomized controlled, open-label trial enrolled 75 older adults from six activity centers. The participants were randomly assigned, by a random number table technique, to the lecture-based, MAR, or control group. Data on oral healthcare-related knowledge, self-efficacy, and oral health status were collected through questionnaires and oral examinations at baseline, immediately after the intervention, and at a 2-week follow-up. The MAR system's usability was assessed. Statistical analyses, comprising descriptive statistics and inferential tests, were performed. RESULTS: Data from 61 participants were analyzed, 22 in the lecture-based group, 20 in the MAR group, and 19 in the control group. Both lectures and MAR education significantly improved oral health status. However, changes in knowledge and self-efficacy scores were significantly different only for the MAR versus control group (p = .002 and .001, respectively). The MAR group demonstrated better knowledge and self-efficacy retention than did the lecture-based group, without significant difference. Usability assessment revealed potential for improvement in the MAR system. CONCLUSIONS: MAR-integrated oral health education enhanced the knowledge, self-efficacy, and oral health status of community-dwelling older adults. However, addressing technology adoption and usability challenges is vital. Longer-term evaluations and broader geographical studies are recommended.

Developing and assessing the efficiency of VOSER software in recording dental caries according to WHO's criteria 2013.

Background/purpose: World Health Organization (WHO) oral health survey manual is the main guideline for most oral health surveys worldwide. It has been updated several times since 1971; however, using papers and pens for data recording remains unchanged. This study aimed to develop the Vietnam Oral Survey Electronics Recorder (VOSER) to record dental caries data based on the WHO 2013 criteria and assess its reliability and efficiency. Materials and methods: VOSER was developed and tested for reliability and efficiency by performing clinical examinations on 365 school children in three key indicator age groups: 120 5-year-old students with primary dentition, 123 8-year-old students with mixed dentition, and 122 12-year-old students with permanent dentition. One gold standard examiner and two trained clerks examined these children using either WHO's paper survey form or VOSER's digital form for dental caries. Recording time, spreadsheet time, DMFT/S, and dmft/s were analyzed to compare the efficiency of VOSER to the paper form. Cohen's Kappa, intraclass correlation coefficient, and Wilcoxon signed-rank test were adopted in the data analyses. Results: Median time of using VOSER was significantly shorter than the standard time in all three dentitions (P < 0.001). Cohen's Kappa values between data collected by VOSER and paper form showed almost perfect agreements (0.927-0.958). DMFT/S and dmft/s values calculated from data collected by both methods had good to excellent reliabilities (0.791-0.997). Conclusion: VOSER is efficient and reliable for conducting dental caries surveys according to the WHO 2013 criteria and should be utilized in the era of digital technology.

A mobile augmented reality-integrated oral health education for community dwelling older adults: A pilot study.

Background/purpose: Providing oral healthcare education can be an optimal strategy for imparting knowledge and developing self-care skills for older adults to enhance their oral health conditions. However, traditional passive lecture-based education programs have several limitations. Integrating mobile augmented reality (MAR) into oral health education can potentially enhance the effectiveness of the education by mitigating those limitations. The objectives of this study are to develop and evaluate the effectiveness of MAR-integrated oral health education. The objectives of this study were to develop and evaluate the effectiveness of MAR-integrated oral health education. Materials and methods: Twenty-four older adults from community dwellings participated in this study. The participants received MAR-integrated oral health education once at activity centers. Self-report questionnaires were utilized to assess oral healthcare-related knowledge and self-efficacy, and the usability score of the MAR system. The assessment was conducted before and after the educational program. Data were statistically analyzed using descriptive statistics and paired-t test. Results: The mean scores of oral healthcare-related knowledge and self-efficacy showed a significant increase after the educational program, with P-values of <0.001 and 0.002, respectively. A majority of the participants exhibited a lack of knowledge and self-efficacy regarding the proper selection of toothpaste and interdental brushes. However, there was an improvement after the intervention. The usability score of the system was lower than the average level. Conclusion: MAR-integrated oral health education effectively increases oral health-related knowledge and self-efficacy among community dwelling older adults. Still, the usability of the MAR system needs to be improved. Further investigation of long-term effects and clinical outcomes, and the inclusion of comparative groups are recommended for the future study.

Survival of Four Conical Implant Abutment Connections After Removal of the Abutment Screw and Simulated Cyclic Loading: An In Vitro Comparative Study.

This in vitro study evaluated the mechanical behavior of different conical connection implant systems after abutment screw withdrawal. Four conical connection systems were selected based on different conical half-angles: Ankylos (5.7°), Cowell (7.0°), Straumann (7.5°), and Astra (11.0°). In each system, 5 implants and abutments were used (n = 5). According to the recommended value, each abutment screw was torqued to settle the abutment and then withdrawn through a predesigned hole of the cemented crown. The retentiveness of the abutment was evaluated by the following mechanical testing. All specimens were subjected to cyclic loading of 20-200 N, 30°, and 4-mm off-axis to the implant axis, for 106 cycles. The pullout forces and axial displacements of the abutments were measured. The data of the Cowell system was obtained from our previous work. All groups other than Astra group, in which abutment loosened after abutment screw withdrawal, passed the cyclic loading test. Straumann group demonstrated a significantly lower pullout force (27.4 ± 21.1 N) than Ankylos (160.1 ± 41.4 N) and Cowell (183.7 ± 30.5 N) groups. All groups showed abutment rebound after screw withdrawal except Straumann group. In addition, Ankylos, Cowell, and Straumann groups demonstrated axial displacement after cyclic loading. In terms of the retentiveness of the abutment after abutment screw withdrawal examined in this study, Ankylos and Cowell groups had much higher retentiveness than Straumann group, while Astra group had none. Conical angle could be a key design parameter to make abutment screw withdrawal after conical abutment settlement feasible, but more studies must be conducted for clinical application.

Profiles of oral microbiome associated with nasogastric tube feeding.

Background: Dysbiosis of oral microbiome causes chronic diseases including dental caries and periodontitis, which frequently affect older patient populations. Severely disabled individuals with impaired swallowing functions may require nutritional supply via nasogastric (NG) tubes, further impacting their oral condition and possibly microbial composition. However, little is known about the effect of NG tube on oral microbes and its potential ramification. Methods: By using 16S rRNA amplicon sequencing, we characterized the tongue microbiome of 27 patients fed with NG tubes and 26 others fed orally. Results: The microbial compositions of NG-tube and oral-feeding patients were substantially different, with more Gram-negative aerobes enriched in the presence of NG tube. Specifically, NG-tube patients presented more opportunistic pathogens like Pseudomonas and Corynebacterium associated with pneumonia and lower levels of commensal Streptococcus and Veillonella. Co-occurrence analysis further showed an inverse relationship between commensal and pathogenic species. Conclusion: We present a systematic, high-throughput profiling of oral microbiome with regard to long-term NG tube feeding among the older patient population.

Effects of core buildup composite resin translucency on intraoral scanner accuracy: an in vitro study.

AIM: The accuracy of 3D images produced by an intraoral scanner (IOS) is affected by the optical characteristics of restorative materials such as metal, ceramic, and composite resin. The present in vitro study aimed to investigate the impact of core buildup composite resin translucency on IOS accuracy. MATERIALS AND METHODS: A core buildup procedure was performed on a proprietary 3D-printed model using injectable composite resins in four groups with different levels of translucency (highest to lowest: AE, A3, AO3, and EX). Ten experimental scans per group were performed using a Medit i700 IOS on a phantom head-mounted model. Reference scans were obtained using an industrial scanner (Solutionix C500). Values of accuracy (trueness and precision) for the respective groups were evaluated using mean deviation values following 3D superimposition. RESULTS: Composite resin translucency caused the scale reduction of the optical impressions. Values of trueness showed the highest scale reduction in AE, significantly, followed by A3, AO3, and EX. Considering 50 µm as the cut-off value of deviations for clinical acceptability, the analysis showed most deviations in AE and A3. Similar results were found with precision, where AE showed the highest deviation value statistically, followed by A3, AO3, and EX. CONCLUSIONS: Composite resin translucency affects the accuracy of optical impressions, causing a fitting error of CAD/CAM prostheses. The more translucent the composite resin, the less accurate the optical impression. This suggests the need for proper compensation during prosthesis designing for an optimal clinical result. In addition, practitioners should indicate in the digital workflow the proper restorative materials regarding not only the mechanical properties and esthetics, but also the optical characteristics.

Effect of cutting flute design features on primary stability of immediate implant placement and restoration: a dynamic experimental analysis.

Self-tapping implants with self-cutting flutes may influence primary stability, especially for the immediate implant placement and restoration protocol in which implants are affixed to the bone in the apical portion. Screw geometry differs between brands, and the effect of apical design on its clinical outcomes remains unclear. This study is aimed at investigating the influence of cutting flute shape (spiral, straight, and without flute) on primary stability by using a dynamic experimental test. Six types of dental implants were designed using computer-aided design and computer-aided manufacturing technology, consisting of three types of cutting flute shapes along with two types of screw features. A dynamic mechanical test was performed using a cyclic loading scheme. The mechanical behaviors of resistance to lateral load (RLL), maximum force, and energy dissipation were compared between groups. In the dynamic test, implants without cutting flute also exhibited higher values in RLL, maximum force, and energy dissipation. The aggressive thread implant with straight flute displayed higher RLL and had a significantly higher values in RLL (p = 0.033) at the threshold point of bone-implant interface breakdown. The implants without cutting flutes exhibited higher primary stability. Straight flute design would improve RLL for aggressive thread implant.

Effects of food hardness on temporomandibular joint osteoarthritis: Qualitative and quantitative micro-CT analysis of rats in vivo.

BACKGROUND: Temporomandibular joint osteoarthritis (TMJ-OA) is a degenerative joint disease in which quantitative analysis based on magnetic resonance image (MRI) or cone-beam computed tomography (CBCT) remains limited. Moreover, the long-term effects of soft food on the adaptive condylar remodeling process in TMJ-OA remain unclear. This study aimed to assess the effects of food hardness on adaptive condylar remodeling in a healthy TMJ, TMJ-OA, and controlled TMJ-OA. METHODS: Complete Freund's adjuvant (CFA) was used for TMJ-OA induction and Link-N (LN) for TMJ repair. Eighteen mature rats were randomly divided into six groups: (1) control/normal diet (Ctrl-N); (2) control/soft diet (Ctrl-S); (3) TMJ-OA/normal diet (CFA-N); (4) TMJ-OA/soft diet (CFA-S); (5) Link-N-controlled TMJ-OA/normal diet (LN-N); and (6) Link-N-controlled TMJ-OA/soft diet (LN-S). Micro-CT was performed 14, 21, and 28 days after CFA injection to analyze the bone volume, bone volume fraction (BVF), bone mineral density (BMD), and trabecular bone number and thickness (Tb.N, Tb.Th). MRI and histological imaging were performed to support the analysis. RESULTS: Under CFA treatment, the BVF and BMD decreased significantly (p < 0.01) and later recovered to normal. However, more significant improvements occurred in normal-diet groups than soft-diet groups. Additionally, bone volume changes were more predictable in the normal-diet groups than in the soft-diet groups. The normal-diet groups presented a significant decrease and increase in the Tb.N and Tb.Th, respectively (p < 0.05), while the Tb.N and Tb.Th in the soft-diet groups remained largely unchanged. Furthermore, a significantly higher frequency of irregularities on the condylar articular surface was found in the soft-diet groups. CONCLUSIONS: Compared with a soft diet, a normal diet may be beneficial for preserving condyle articular surface and directing bone remodeling in TMJ-OA rats.

Evaluation of the potential denture covering area in buccal shelf with intraoral scanner.

Background/purpose: The characteristic of soft tissue changes in buccal shelf area during function is unclear. This study aimed for evaluating the potential denture covering area in buccal shelf area in different ranges of mouth opening by a digital approach. Materials and methods: Nineteen qualified dentate participants were enrolled. An intraoral scanner was used to record soft tissue in buccal shelf area in different ranges of mandibular opening, which were maximum intercuspation, 10 mm, 20 mm, and 30 mm of interincisal distance. The experiment was performed by two examiners. The common area of each range was generated within the clinically acceptable denture adaptation range, which was represented as the potential denture covering area. Data were statistically analyzed using descriptive statistic, one-way repeated measure ANOVA, intraclass correlation coefficient (ICC), and the Pearson correlation test. Results: Trends of the mean distance of the potential denture covering area increased from the frenum area to the second premolar and the first molar area then decreased in the second molar area, along with the ranges of mouth opening increased. The distance in the second molar area had drastic percentage changes during the mouth opening. The mean distances changed significantly when the mouth opening increased (P < 0.001). All ICC values of intra-, inter-rater reliability indicated good to excellent reliability. The correlation between the results from two examiners was strong (P < 0.001). Conclusion: The characteristic of the denture covering area posteriorly to the first molar area is inversely proportional in length to ranges of mouth opening.

Locational effects on oral microbiota among long-term care patients.

BACKGROUND: Dysbiosis of oral microbiota is the cause of many diseases related to oral and general health. However, few Asia-based studies have evaluated the role of oral microbiota in patients receiving long-term care. Thus, new indications are needed for early prevention and risk management based on information derived from the oral microbiota. METHODS: We used next-generation sequencing (NGS) to identify the oral bacterial composition and abundance in patients receiving long-term care: 20 from the outpatient department (OPD) and 20 home-care patients. Their microbial compositions, taxonomy, and alpha/beta diversity were characterized. RESULTS: Microbiota from the two groups showed different diversity and homogeneity, as well as distinct bacterial species. A more diverse and stable microbial population was observed among OPD patients. Our findings indicated that home-care patients had a higher risk of oral diseases due to the existence of dominant species and a less stable microbial community. CONCLUSION: This work was the first in Taiwan to use NGS to investigate the oral microbiota of long-term care patients. Our study demonstrated the potential use of dominant bacterial species as biomarkers for the risk management of posttreatment complications.

Effect of online learning for dental education in asia during the pandemic of COVID-19.

BACKGROUND/PURPOSE: Online learning has been utilized in the world to continue educational activities in dentistry, which was severely affected by the pandemic of coronavirus disease 2019 (COVID-19). The purpose of this study was aimed to evaluate the effect of online learning during the pandemic of COVID-19 in different dental schools of different countries in Asia by the questionnaire survey. MATERIALS AND METHODS: Mantel-Haenszel chi-square tests were used to analyze the difference between dental schools with and without shutdown. A questionnaire-based online survey was used to evaluate the online learning effect on undergraduate students in 13 dental schools of 7 Asia countries and regions. RESULTS: For the question that blended learning class has better learning efficiency, the agreement rate was significantly higher in the students (80.3%) from the dental schools that did not suspend face-to-face education activities than in the students (50.3%) from the dental school that was shut down. CONCLUSION: Within the limitation of this study, it is concluded that a combination of physical and online classes in terms of blended learning courses will be the future trend for dental education.

Current Insights into Oral Cancer Diagnostics.

Oral cancer is one of the most common head and neck malignancies and has an overall 5-year survival rate that remains below 50%. Oral cancer is generally preceded by oral potentially malignant disorders (OPMDs) but determining the risk of OPMD progressing to cancer remains a difficult task. Several diagnostic technologies have been developed to facilitate the detection of OPMD and oral cancer, and some of these have been translated into regulatory-approved in vitro diagnostic systems or medical devices. Furthermore, the rapid development of novel biomarkers, electronic systems, and artificial intelligence may help to develop a new era where OPMD and oral cancer are detected at an early stage. To date, a visual oral examination remains the routine first-line method of identifying oral lesions; however, this method has certain limitations and as a result, patients are either diagnosed when their cancer reaches a severe stage or a high-risk patient with OPMD is misdiagnosed and left untreated. The purpose of this article is to review the currently available diagnostic methods for oral cancer as well as possible future applications of novel promising technologies to oral cancer diagnosis. This will potentially increase diagnostic options and improve our ability to effectively diagnose and treat oral cancerous-related lesions.

Influences of screw design features on initial stability in immediate implant placement and restoration.

BACKGROUND: Self-tapping screws have been extensively used for dental implants. Their biomechanical behavior is highly associated with their clinical success, particularly for screws used for immediate implant placement and restoration, because occlusal forces can directly affect the loading transfer at the bone-implant interface after implantation. The effect of implant design on the initial stability of self-tapping screws remains unclear. This study explored the biomechanical behaviors of implant stability in standardized implants with different design features. METHODS: Six types of dental implants were designed using computer-aided design/computer-aided manufacturing technology, including three types of cutting flute shapes (spiral, straight, and non-self-tapping) combined with two types of screw features. Peak insertion torque values were first recorded; initial stability levels were subsequently evaluated in terms of the maximum force and resistance to lateral loads using an electrodynamic test system. FINDINGS: The peak insertion torque values, maximum force, and resistance to lateral loads of the non-self-tapping groups were higher than those of the self-tapping groups by 17%-90% (p < 0.01). The peak insertion torque values of the Straumann implant with a spiral flute was higher than that of the original straight flute by 20% (p < 0.001). However, compared with the original spiral flute, the Nobel Biocare implant with straight flute had a 23% higher maximum force (p = 0.016) and 24.5% higher resistance (p = 0.012) under lateral loading. INTERPRETATION: Changing the flute design would affect initial implant stability. Non-self-tapping implants exhibited superior initial stability than did self-tapping implants.

Application of masticatory control in dental treatment for elderly individuals.

Taiwan transitioned to an aged society in 2018. Appropriate dental treatment is important for elderly individuals. Previously, reconstruction of the dentition was thought to help regain chewing function. However, concerns of the elderly population, such as decline in learning ability and saliva secretion, complicate dental reconstruction. Overlooking the special needs of elderly individuals may lead to impaired chewing function, resulting in nutritional imbalances and increased burden on the digestive tract, causing more health disorders. For the elderly population, treatment must be aimed at restoring as much chewing function as possible with minimal changes. Additionally, regular oral hygiene care, proper design of fixed partial dentures, and implant placement greatly reduce the difficulty in adapting to a new prosthesis. These measures allow us to provide better quality of life for elderly individuals.

Innovation of dental education during COVID-19 pandemic.

BACKGROUND/PURPOSE: The impact of the pandemic of COVID-19 has a certain influence on various walks of life around the world. Because of the pandemic of this novel coronavirus in terms of COVID-19, the social life global wide has been changed a lot. To keep the social distance between human being to prevent from being infected is the most important strategy for all the countries. Many dental schools have been locked down to minimize the spread out of this coronavirus infection. Close contact between human being are required for all those learning process in traditional dental education. Learning methods should be innovated to keep on the learning process but away from being infected for dental education during pandemic. The purpose of this manuscript is to exchange the information and experience of those dental educators from different countries to prepare for the future demand for dental education during pandemic. MATERIALS AND METHODS: By means of three online symposiums, dental educators from different countries were invited to give presentation and discussion regarding to the information and experience in the innovation of dental education during the pandemic. RESULTS: The results showed that the impact of the pandemic of COVID-19 affects the dental education a lot. Intelligent technology has certain benefit for the learning process of dental education during the pandemic. CONCLUSION: The impact of the pandemic of COVID-19 affects dental education a lot. The model of dental education should be innovated to suit different situations and novelty intelligent technology should be applied for future dental education.

Guidelines for innovation in dental education during the coronavirus disease 2019 pandemic.

During the current coronavirus disease 2019 (COVID-19) pandemic, dental education and training requiring face-to-face interaction must prioritize infection prevention and the safety of students, staff, and patients. In July 2020, the Association for Dental Education, Asia Pacific (ADEAP) published safety guidelines for safe dental education during the COVID-19 pandemic. These guidelines summarize ADEAP recommendations for classroom-based courses, reopening of simulated training courses and dental clinics, and provision of clinical skills training courses in dentistry during the COIVID-19 pandemic. They have been formulated to ensure the safety of students and teaching staff, dental auxiliary staff, and patients. However, the present guidelines are considered appropriate only when the number of COVID-19 epidemic cases has been significantly reduced, i.e. when the epidemiological curve has flattened in the area concerned. The criteria for lifting restrictions on activities should be consistent with relevant jurisdictional guidelines.

Stress and its association with academic performance among dental undergraduate students in Fujian, China: a cross-sectional online questionnaire survey.

BACKGROUND: The aim of this study was to investigate the amount and sources of stress in dental undergraduate students in Fujian, China, and the factors associated with stress. METHODS: This cross-sectional study was conducted during the second semester of the 2017-2018 academic year at the School of Stomatology, Fujian Medical University, China. A total of 396 students were surveyed with the Dental Environment Stress Questionnaire (DES) and the Perceived Stress Scale (PSS) using an online survey system. The participants' demographic information, including sex, age, year of study, and grade point average (GPA) was also collected. One-way analysis of variance (ANOVA) was performed to compare the stress scores. Pearson correlation and multiple linear regression analyses were conducted to explore the associated factors of stress and academic performance. All statistical analyses were performed at a significance level of 5%. RESULTS: A total of 347 undergraduate students participated in the present study, for a response rate of 87.6%. There were no significant differences in the DES and PSS total scores among students of different grades and sexes. Significant differences were found in the DES "workload" and "self-efficacy beliefs" scores among students from different study years (all P < 0.05). The Multiple linear regression showed that DES and PSS scores were negatively correlated with GPA, while sex was positively correlated with GPA (all P < 0.05). Female students had significantly higher GPAs than male students. CONCLUSIONS: Dental undergraduates in Fujian, China experienced moderate levels of stress. While the amount of stress did not differ by year of study, the sources of stress did differ. Stress scores and sex were negatively correlated with academic performance.