Predictors of survival of large non-occlusal non-incisal glass-ionomer restorations in older adults.

PURPOSE: This study aimed to investigate the predictors of survival of non-occlusal non-incisal glass-ionomer restorations as a surrogate for root surface restorations among older adults. METHODS: In a retrospective cohort analysis using the University of Iowa College of Dentistry electronic dental records, we included 721 patients aged 65+ who received 2+ surface non-occlusal non-incisal glass ionomer restorations placed from January 2005 - December 2011. Restorations were followed until September 2017 or until they were deemed to have failed. RESULTS: At baseline, participants' mean age was 77.6 ± 8.2 years, and 45.8% were females. Most patients were self-pay (65.2%). Most restorations were placed by residents and dental students (82.7%) and included only two surfaces (95.6%). About half (49.1%) failed during follow-up, with a median survival time of 3.7 years. The time ratio for lower incisors compared to other teeth was 0.6 (p = .006), for three-and-four-surface restorations compared to two was 0.7 (p = .007), for faculty as providers compared to residents and students was 1.4 (p = .039), and for the Geriatric & Special Needs Clinic compared to others was 0.8 (p = .013). Time ratios less than one indicate association with shorter durations for restorations, and time ratios greater than one indicate association with longer durations for restorations. CONCLUSION: Tooth type, number of restored surfaces, provider type, and clinic were all significant factors associated with survival of these restorations.

An Overview of Meta-analysis for Dental Researchers.

In order to keep clinical norms aligned with evidence-based practices, dental researchers need to be equipped to read and evaluate meta-analyses. Moreover, clinician scientists in dentistry should be prepared to lead investigations that incorporate meta-analysis. This article provides an overview of the principles and practices that will equip dental researchers to engage in meta-analysis work. Six elements of meta-analysis are addressed: formulating a research question, searching the literature, collecting the data, aggregating the data, analyzing the data, and interpreting results and drawing generalizations. Readers are guided through each of these stages of research so that they can recognize and implement robust, reproducible meta-analysis work.

Perceived social status, socioeconomic status, and preventive dental utilization among a low-income Medicaid adult population.

OBJECTIVES: Perceived Social Status (PSS) is a measure of cumulative socioeconomic circumstances that takes perceived self-control into account. It is hypothesized to better capture social class compared to socioeconomic status (SES) measures (i.e., education, occupation, and income). This study examined the association between PSS and dental utilization, comparing the strength of associations between dental utilization and PSS and SES measures among a low-income adult Medicaid population. METHODS: A cross-sectional survey was administered to a random sample of low-income adults in Iowa, United States with Medicaid dental insurance (N = 18,000) in the spring of 2018. Respondents were asked about PSS, dental utilization, and demographics. A set of multivariable logistic regression models examined the relative effects of PSS and SES measures on dental utilization, controlling for age, sex, health literacy, whether the respondent was aware they had dental insurance, transportation, and perceived need of dental care. RESULTS: The adjusted response rate was 25%, with a final sample size of 2252. Mean PSS (range 1-10) was 5.3 (SD 1.9). PSS was significantly associated with dental utilization (OR = 1.11; CI = 1.05, 1.18) when adjusting for control variables, whereas other SES measures-education, employment, and income-were not. CONCLUSIONS: PSS demonstrated a small positive association with dental utilization. Results support the relative importance of PSS, in addition to SES measures, as PSS may capture aspects of social class that SES measures do not. Results suggest the need for future research to consider the effects of PSS on oral health outcomes and behaviors.

The Dental Researcher's Guide to Data Analysis - Part 2.

It is important for dental researchers to have a general idea of the different types of data that can be collected from a study and the available statistical tools that can be used with such data. By knowing about what is available, researchers will have an informed idea of the types of studies that should be conducted, the data that should be collected, and the proper statistical methods for analyzing collected data. In the first part of this general overview of statistical methods, we walked through the various types of data that traditional statistical techniques, such as t tests and linear regression, can handle. In this second part, we explore more complex types of data that traditional statistical techniques are unable to handle. Specifically, we discuss longitudinal and time-to-event data because both occur frequently in dental studies and require special modeling techniques in order to analyze correctly. Using two different simulated dental datasets, the proper application of techniques such as repeated measures ANOVA, linear mixed modeling, generalized estimating equations, log-rank test, and Cox proportional hazards models are discussed and illustrated in depth.

The Dental Researcher's Guide to Data Analysis: Part 1.

One of the most important parts of any research project is the statistical analysis through which results are described and deemed significant or otherwise. Given this role of statistical analyses, it is imperative to understand what statistical tests are available and, most importantly, when they are appropriate. This is because choosing an improper statistical test can lead to inaccurate results and meaningless conclusions. We have written this data analysis guide to assist dental researchers with carrying out a proper analysis plan in consultation with a statistician. In this first part, we detail common types of outcome and predictor variables and include some common tests that can be used for each scenario. Using different simulated datasets, we also provide examples of common data visualization techniques and how a proper statistical test can be applied. We hope this guide provides some general background knowledge on common statistical techniques and allows for easier and more effective conversations with your statistician.

Correlation in Dental Studies: Why It Matters and What to Do About It.

In dental research, it is particularly common for studies to collect data that are fundamentally correlated. Some common dental situations in which correlation arises include patients being observed across multiple teeth and/or across multiple time points, such as before and after treatment, or groups of patients being clustered (ie, familial units). For a number of traditional statistical tests and modeling techniques, the assumption of independence between observations is imperative in order to receive valid results and make accurate conclusions. This article describes how ignoring inherent correlations in data can lead to erroneous results when using traditional methods as well as the types of modeling techniques that are available to handle correlated data. Furthermore, two simulation studies are performed to further illustrate and prove the advantages of adequately handling correlated data in statistical analyses. Int J Oral Maxillofac Implants 2023;38:417-421. doi: 10.11607/jomi.10285.

Empathy levels among health professional students at a large midwestern public university - a cross-sectional study.

BACKGROUND: Empathic care is considered extremely important by patients and providers alike but there is still an ample need for assessing empathy among healthcare students and professionals and identifying appropriate educational interventions to improve it. This study aims to assess empathy levels and associated factors among students at different healthcare colleges at the University of Iowa. METHODS: An online survey was delivered to healthcare students, including nursing, pharmacy, dental, and medical colleges (IRB ID #202,003,636). The cross-sectional survey included background questions, probing questions, college-specific questions, and the Jefferson Scale of Empathy-Health Professionals Student version (JSPE-HPS). To examine bivariate associations, Kruskal Wallis and Wilcoxon rank sum tests were used. A linear model with no transformation was used in the multivariable analysis. RESULTS: Three hundred students responded to the survey. Overall JSPE-HPS score was 116 (± 11.7), consistent with other healthcare professional samples. There was no significant difference in JSPE-HPS score among the different colleges (P = 0.532). CONCLUSION: Controlling for other variables in the linear model, healthcare students' view of their faculty's empathy toward patients and students' self-reported empathy levels were significantly associated with students' JSPE-HPS scores.

Triad multisystem phenotype with high risk for developing temporomandibular disorders-characteristics and potential pathophysiology results from the Orofacial Pain: Prospective Evaluation and Risk Assessment dataset.

ABSTRACT: A multisystem phenotype with the Triad of bodily pain, psychological distress, and sleep disturbance was found to have high risk for developing initial onset of painful temporomandibular disorders (TMDs) in the multicenter Orofacial Pain: Prospective Evaluation and Risk Assessment dataset. In this study, we systemically examined phenotypic characteristics and explored potential pathophysiology in quantitative sensory testing and autonomic nervous system domains in this multisystem Triad phenotype. Secondary analysis was performed on 1199 non-Triad and 154 Triad TMD-free Orofacial Pain: Prospective Evaluation and Risk Assessment enrollees at baseline. Results indicated that before developing TMDs, the Triad phenotype demonstrated both orofacial and systemic signs and symptoms that can only be captured through multisystem assessment. In addition, we found significantly lower resting heart rate variability and higher resting heart rate in the Triad phenotype as compared with the non-Triad group. However, pain sensitivity measured by quantitative sensory testing was not different between groups. These findings highlight the importance of whole-person multisystem assessment at the stage before developing complex pain conditions, such as TMDs, and suggest that, in addition to a "tissue damage monitor," pain should be considered in a broader context, such as a component within a "distress monitoring system" at the whole-person level when multisystem issues copresent. Therefore, the presence or absence of multisystem issues may carry critical information when searching for disease mechanisms and developing mechanism-based intervention and prevention strategies for TMDs and related pain conditions. Cardiovascular autonomic function should be further researched when multisystem issues copresent before developing TMDs.

Effect of silver nanoparticles associated with fluoride on the progression of root dentin caries in vitro.

OBJECTIVES: To assess the anti-proteolytic effect and potential to inhibit dentin root caries progression of a silver nanoparticle and fluoride solution (CNanoF) in comparison to silver diamine fluoride (SDF). METHODS: 48 specimens of root dentin artificial caries lesion were treated with 38% SDF, CNanoF, CNano or F (n = 6 per group). Ph cycling with demineralization and remineralization solutions simulated caries lesion progression. In addition, specimens were incubated with or without bacterial collagenase in the remineralization solution to induce dentin proteolytic degradation. Dentin degradation was assessed by weight loss rate and hydroxyproline (Hyp) release. Changes in cross-sectional microhardness, and lesion permeability and collagen integrity as determined by confocal laser scanning microscopy indicated potential for further demineralization inhibition. The effect of the solutions on the activity of metalloproteinases (MMP) -2 and -9 was also investigated. Statistical analysis consisted of ANOVA, Kruskal-Wallis, and linear mixed models with post-hoc pairwise Tukey, Dunn, and t-tests (α = 0.05). RESULTS: Treatment with SDF resulted in lower weight loss rate than did other solutions, but all groups showed similar Hyp release (p = 0.183). SDF resulted in greater microhardness at superficial layers of the caries lesions (p<0.05), while there were no differences among CNanoF, CNano, and F. Lesion permeability was similar among all groups after pH cycling (p>0.05), with or without the use of collagenase (p = 0.58). No statistically significant difference was noted among solutions regarding collagen integrity after pH cycling; however, SDF-treated dentin had a significant decrease in collagen integrity when collagenase was used (p = 0.003). Interestingly, only SDF was able to completely inactivate MMP-2 and -9. CONCLUSIONS: CNanoF and SDF both potentially prevent dentin degradation during caries lesion progression in vitro; however, SDF was more effective at inhibiting further tissue demineralization.

Development and validation of a nursing home mortality index to identify nursing home residents nearing the end of life in dental clinics.

BACKGROUND: Nursing home (NH) residents seek care at dental offices, yet many of them are at the end of life. The uncertain life expectancy further complicates the care of NH residents. This study aimed to develop and validate a Nursing Home Mortality Index (NHMI) to identify NH residents in the last year of life. METHODS: Logistic modeling was used to develop predictive models for death within 1 year after initial appointment by utilizing the new patient examination data and mortality data of 903 Minnesota NH residents. The final model was selected based on areas under the curve (AUC) and then validated using data from 586 Iowa NH residents. Based on the final model, the NHMI was developed with the estimated 1-year mortality for the low, medium and high risk group. RESULTS: One-year mortalities were 21% and 26% in the development and validation cohorts, respectively. Predictors included age, gender, communication capacity, physical mobility, congestive heart failure, peripheral vascular disease, cancer, cerebrovascular disease, chronic renal disease and liver disease. AUCs for the development and validation models were 0.73 and 0.68, respectively. For the validation cohort, the sensitivity and specificity were 0.79 and 0.53, respectively. The estimated 1-year mortality risks for three risk groups were 0%-10%, 11%-19%, and ≥20%, respectively CONCLUSION: The high mortality rate of NH residents following a dental exam highlighted a need to incorporate patients' prognoses in treatment planning along with normative needs and patients' preferences. The NHMI provides a practical way to guide treatment decisions for end-of-life NH residents.

Role of mutans streptococci, acid tolerant bacteria and oral Candida species in predicting the onset of early childhood caries.

Aim: Early childhood caries is the most common chronic infectious disease in children in the United States. This study, which is part of a larger, longitudinal study exploring oral microbiological components of caries development in children, reports on the impact of total mutans streptococci (MS), total acid tolerant bacteria and Candida species on the development of dental caries in a subset of these children. Of particular interest was the relationship between caries development and co-colonization of mutans streptococci and Candida species. Methods: Children between the ages of 12 and 47 months displaying no evidence of dental caries were recruited for a longitudinal study (n = 130). Twelve age- and gender-matched pairs were selected. In each pair, one child developed caries during the study, and one did not. Whole mouth plaque samples were collected by swab at baseline and every 6 months thereafter for a duration of 18 months and spiral plated for microbial counts (CFU/ml). Cut-offs based on percent of total cultivable flora were designated for all microbial measures. A scoring system designated the Plaque Microbial Index (PMI) was developed for use in statistical analyses to assess potential predictive factors for caries risk assessment. Results: Children who developed caries were significantly more likely to harbor higher percentages of acid tolerant bacteria (p = 0.003), MS (p < 0.001) and have Candida species present (p < 0.001) at ≥1 visit leading up to caries onset. Mean PMI scores derived from the aforementioned microbial measures, were higher for caries active children than caries free children (p = 0.000147). Co-colonization of MS and Candida species was significantly associated with caries development (p < 0.001) and detection of both at the same visit had a 100% positive predictive value and 60% negative predictive value for caries development. Conclusion: In children who developed caries, there was a statistically significant association with the percent of total flora that was acid tolerant, the percent of MS, the presence of Candida and co-colonization of MS and Candida species. Combining these microbial measures into PMI scores further delineated children who developed caries from those who remained caries-free. These microbiological measures show potential as predictive factors and risk assessment tools for caries development.

Systematic review and meta-analysis of oral squamous cell carcinoma associated oral microbiome.

The intersection between the human oral microbiome and oral health is an emerging area of study which has gained momentum over the last decade. This momentum has motivated a search for associations between the oral microbiome and oral cancer, in hopes of identifying possible biomarkers that facilitate earlier diagnosis and improved prognosis for patients with that disease. The present study examined the relationship between the microbiome in the human oral cavity and oral squamous cell carcinoma (OSCC). We searched the literature for case-control studies which focused on the relationship between the human oral microbiome and OSCC. We aggregated three types of data from these studies: bacteriome data at the genus level, predicted functional pathway data, and gene abundance data. From these data, we noted several microbial genera which may be associated with oral cancer status, including Fusobacterium. We also identified functional pathways which merit further investigation, including RNA degradation (ko03018) and primary immunodeficiency (ko05340). In addition, our analysis of gene abundance data identified the gene K06147 (ATP-binding cassette, subfamily B, bacterial) as being over abundant in OSCC samples. Our results are generalizations which identified some currents that we believe could guide further research. Our work faced several limitations related to the heterogeneity of the available data. Wide variation in methods for sample collection, methods for controlling for known behavioral risk factors, computing platform choice, and methods for case-control design all posed confounding factors in this work. We examined the current methods of data collection, data processing, and data reporting in order to offer suggestions toward the establishment of best practices within this field. We propose that these limitations should be addressed through the implementation of standardized data analytic practices that will conform to the rigor and reproducibility standards required of publicly funded research.

Bayesian Statistics: A Walkthrough with a Simulated Dental Dataset.

When a clinician sees a patient with a complication, they often go through a Bayesian style of logic, most likely without even knowing it. They assess whether they have seen the complication before, provide an intervention based on historical knowledge of what leads to improvement, and then later assess how the intervention is performed. This process, which is routine in clinical practice, can be mathematically extended into an alternative way of performing statistical analyses to assess clinical research. However, this process is contrary to the most common statistical methods used in dental research: frequentist statistics. Though powerful, frequentist methods come with advantages and disadvantages. Bayesian statistics are an alternative method, one that mirrors how we as researchers think and process new information. In this primer, a walkthrough of Bayesian statistics is performed by constructing priors, defining the likelihood, and using the posterior result to draw conclusions on parameters of interest. The motivating example for this walkthrough was a Bayesian analog to logistic regression, fit using a simulated dental-related dataset of 50 patients who received a dental implant-classified as either within or outside normal limits-from practitioners who did or did not receive a training course in implant placement. The results of the Bayesian and traditional frequentist logistic regression models were compared, resulting in very similar conclusions regarding which parameters seemed to be strongly associated with the outcome.

Prevalence of non-cavitated lesions and progression, regression, and no change from age 9 to 23 years.

OBJECTIVES: Some non-cavitated caries lesions (D1 ), the initial stage of caries, progress to cavitation. This article reports participant-level and surface-level D1 prevalence and changes in status of D1 lesions through different periods from age 9 to 23. METHODS: The Iowa Fluoride Study (IFS) participants were followed longitudinally; all permanent tooth surfaces were examined clinically for caries at ages 9, 13, 17, and 23 using standardized criteria for sound (S), questionable (D0 ), non-cavitated (D1 ), cavitated (D2+ ), filled (F), or missing due to decay (M). D1 lesions at the beginning of each interval were reassessed at each follow-up age to determine transitions (to the 5 categories or no transition). RESULTS: The sample had relatively high socioeconomic status (SES), with about 52%-55% high SES, 32-35% middle SES, and 12-13% low SES. Person-level prevalences of D1 lesions were 23%, 38%, 60%, and 45% at ages 9, 13, 17, and 23, respectively. Surface-level prevalences were less than 1% at ages 9 and 13, 3% at 17, and 2% at 23. Thirteen percent of D1 s at age 9 progressed at 13, 18% progressed from 13 to 17, and 11% progressed from 17 to 23. The percentages regressing (to sound or D0 ) were 72%, 54%, and 72%, respectively. CONCLUSION: Non-cavitated lesions were more prevalent at age 17 than at ages 9, 13, and 23. The high rates of regression compared to progression or no change suggest that many non-cavitated lesions do not progress to cavitated lesions and could be reversed; therefore, surgical intervention should not be the treatment of choice for incipient lesions.

Tooth Agenesis Patterns in Orofacial Clefting Using Tooth Agenesis Code: A Meta-Analysis.

Individuals with orofacial clefting (OFC) have a higher prevalence of tooth agenesis (TA) overall. Neither the precise etiology of TA, nor whether TA occurs in patterns that differ by gender or cleft type is yet known. This meta-analysis aims to identify the spectrum of tooth agenesis patterns in subjects with non-syndromic OFC and controls using the Tooth Agenesis Code (TAC) program. An indexed search of databases (PubMed, EMBASE, and CINAHL) along with cross-referencing and hand searches were completed from May to June 2019 and re-run in February 2022. Additionally, unpublished TAC data from 914 individuals with OFC and 932 controls were included. TAC pattern frequencies per study were analyzed using a random effects meta-analysis model. A thorough review of 45 records retrieved resulted in 4 articles meeting eligibility criteria, comprising 2182 subjects with OFC and 3171 controls. No TA (0.0.0.0) was seen in 51% of OFC cases and 97% of controls. TAC patterns 0.2.0.0, 2.0.0.0, and 2.2.0.0 indicating uni- or bi-lateral missing upper laterals, and 16.0.0.0 indicating missing upper right second premolar, were more common in subjects with OFC. Subjects with OFC have unique TA patterns and defining these patterns will help increase our understanding of the complex etiology underlying TA.

Survival analysis of crown margin repair: A retrospective study in a dental school setting.

BACKGROUND: Repairing crowns with defective margins is minimally invasive and cost-effective compared with replacement. The authors' objectives were to examine the survival trajectory of crown margin repairs and to determine the factors associated with survival. METHODS: Records of adult patients from January 2008 through August 2019 were reviewed for crown margin repairs completed at University of Iowa College of Dentistry. A total of 1,002 crown margin repairs were found. Each repair was followed through the end of study in 2019 or until an event (for example, additional repair, endodontic treatment, crown replacement, or extraction). A Cox proportional hazards model was used to study the relationship between selected covariates and time to event. RESULTS: During the follow-up period, 32.8% of the repairs needed reintervention. In the final model, repair material was the only significant covariate. No difference was found between the survival of repairs done with resin-modified glass ionomer and amalgam. However, the repairs done with resin-based composite and conventional glass ionomer were more likely (1.5 times: 95% CI, 1.02 to 2.10 times; and 2 times: 95% CI, 1.40 to 2.73 times, respectively) to need reintervention than were those done with amalgam. CONCLUSIONS: Median survival time of crown margin repairs was 5.1 years (95% CI, 4.48 to 5.72 years). Median survival times for amalgam, resin-modified glass ionomer, resin-based composite, and glass ionomer repair materials were 5.7 years (95% CI, 4.80 to 6.25 years), 5.3 years (95% CI, 4.73 to 6.34 years), 3.2 years (95% CI, 2.51 to 6.19 years), and 3.0 years (95% CI, 2.53 to 3.62 years), respectively. PRACTICAL IMPLICATIONS: When considering crown margin repairs, resin-modified glass ionomer or amalgam is preferable to resin-based composite or glass ionomer.

Surgery start time and early implant failure: A case-control study.

OBJECTIVE: To evaluate the influence of surgery start time (SST) and other patient- and therapy-related variables on the risk for early implant failure (EIF) in an academic setting. MATERIAL AND METHODS: Data were extracted from the electronic health records of 61 patients who had at least one EIF and 140 age- and gender-matched, randomly selected, non-EIF controls. Bivariate and multivariable analyses were performed to identify relevant associations between EIF and different variables, such as SST. RESULTS: Incidence of EIF was not significantly associated with SST (HR: 1.9 for afternoon implant placement, 95% CI: 0.9-3.9; p = .105). Other factors that were associated with a significantly increased risk for EIF in a multivariable model were pre-placement ridge augmentation (HR: 7.5, 95% CI: 2.2-25.1; p = .001), intra-operative complications (HR: 5.9, 95% CI: 2.2-16.3; p < .001), simultaneous soft tissue grafting (HR: 5.03, 95% CI: 1.3-19.5; p = .020), simultaneous bone grafting (HR: 3.7, 95% CI: 1.6-8.8; p = .002), and placement with sedation (HR: 3.4, 95% CI: 1.5-7.5; p = .002). CONCLUSIONS: While SST was not associated with the occurrence of EIF in our cohort, other variables, such as ridge augmentation prior to implant placement, simultaneous bone or soft tissue grafting, intra-operative complications, implant placement with sedation, and number of implants in the oral cavity, were associated with an increased risk for this adverse event.

Chairside risk assessment for first-onset temporomandibular disorders: Result from the Orofacial Pain: Prospective Evaluation and Risk Assessment data set.

BACKGROUND: Temporomandibular disorders (TMD) risk assessment is difficult in general dentistry owing to the complexity of multifactorial risk contributions and the lack of standardized education. The authors explored a health history-based chairside risk assessment. METHODS: Secondary data analysis was performed on the Orofacial Pain: Prospective Evaluation and Risk Assessment data set. Potential demographic, systemic, and local risk contributors were conceptualized into 10 risk categories. Multivariate Cox proportional hazards modeling with backward selection was applied. Variables with P values < .05 were kept in each successive model. RESULTS: The analysis included data from 2,737 participants. The final model indicated that people with any psychological conditions, pain disorders, sleep disorders, or orofacial symptoms were at elevated risks of developing first-onset TMD. Results of post hoc analysis showed the coexistence of conditions from multiple body systems conferred greater risk of developing TMD. CONCLUSIONS: Coexisting conditions and symptoms from multiple body systems substantially increase the risk of developing TMD pain. Therefore, multisystem risk assessment and interprofessional collaborations are important for the prevention of TMD. PRACTICAL IMPLICATIONS: Dentists should include psychological conditions, pain disorders, sleep disorders, and orofacial symptoms when assessing patients' risk of developing TMD pain.

Types of dental procedures provided to adults with autism spectrum condition: A descriptive study.

PURPOSE/AIM: To investigate demographic and systemic health characteristics, and the types of dental procedures performed for adults with autism that had sought care at a dental school. MATERIALS AND METHODS: De-identified data were collected from the records of patients aged 18+ who have self-reported autism. Each patient's age, gender, BMI, mental health, heart disease, xerostomia, tobacco use, alcohol use, diabetes, use of drugs, seizures, and total number of medications, as well as the type and number of dental codes used in the care of that patient within each code category were included as variables. RESULTS: The sample was composed by 244 patients. Mean age was 29.8 years (±12.3), 64.8% were males, and mean BMI was 29.9 (±8.1). Mental health condition was reported by 79.9%, heart disease by 25.4%, xerostomia by 21.7%, 20.9% reported using tobacco, 18.9% reported using alcohol, 14.8% reported having diabetes, 10.2% reported using drugs, and 3.7% reported having seizures. The median number of dental procedures per patient was nine, and exams, preventive, operative, and surgical procedures were the most common ones. CONCLUSIONS: Adult patients with autism were overweight/obese young males. Most common dental procedures were exams, followed by preventive, operative, and surgical procedures.

COVID-19 pandemic and its impact on dental students: A multi-institutional survey.

PURPOSE/OBJECTIVES: To investigate dental students' perceptions and concerns regarding the COVID-19 pandemic, their coping strategies and support resources, and their perceived stress levels. METHODS: A customized 19-item survey and the perceived stress scale (PSS) were applied to undergraduate dental students from the US, Spain, Ireland, Chile, India, and Brazil between April 10 and July 5, 2020. Linear modeling and mediation analysis were used to explore the relationships among demographics, stressors, coping mechanisms, social support, and stress RESULTS: A total of 4475 students responded to the survey. The majority (72.4%) were women, and 52.3% had no COVID-19 training at the time of the survey. The students reported that they had to accommodate to changes in patient care (96.6%) and didactic learning (95.2%) activities, while 88.5% of the respondents indicated at least one of their courses moved online. Transition to online courses went "smoothly with some troubles" for 51.8% of the respondents, and 48.3% perceived the faculty as prepared for the online transition; however, 45.9% reported feeling extremely concerned about the impact of COVID-19 on their education. The average PSS score was 21.9 of 40 (moderate stress). Multivariate models were built for participants with full data (n = 3899). Being male, having completed more dental coursework, and perceiving a smoother transition were associated with lower PSS scores; more concern about academic progress was associated with higher PSS. Faculty support mediated the relationship between a smoothness of transition and concern about academic progress and PSS scores CONCLUSION: Stress caused by the pandemic may be alleviated by smoother transition and good faculty support.