CAD/CAM leucite-reinforced glass-ceramic for simulation of attrition in human enamel in vitro.

OBJECTIVE: Investigate attrition simulation using CAD/CAM leucite-reinforced glass-ceramic antagonists on occlusal vs. buccal enamel. METHODS: Three dental materials with known wear rates (resin-modified glass-ionomer, micro-filled, and fine particle composites) validated the wear simulator (CAD/CAM glass-ceramic antagonists, 200 cycles, 80 N load, deionised water irrigation, 0.7 mm sliding movement). Following this, human molars were sectioned into paired occlusal and buccal polished samples (n = 8/gp). Exposed 1.5 mm Ø enamel areas were subjected to attritional wear with and without pre-immersion in citric acid (5 min, 0.3%, pH 3.8). Profilometry measured step-height enamel wear and surface microhardness at different depths was calculated using Vickers indentation at 0.1 N and 0.5 N loads. RESULTS: Dental material wear using the CAD/CAM antagonists showed consistency with previous data: mean (SD) resin-modified glass ionomer material loss of 177.77 (16.89) µm vs. 22.15 (1.30) µm fine particle hybrid composite resin wear vs. 13.63 (1.02) µm micro filled composite resin wear (P < 0.001). The coefficient of variation was less than 10%. Following validation, enamel sample wear was significantly increased when attrition was introduced (P < 0.001) independent of buccal vs. occlusal sample location (P < 0.05). Attrition resulted in occlusal wear of 26.1 ± 4.5 µm vs. buccal 26.3 ± 1.2 µm and attrition/erosion resulted in occlusal wear of 26.05 ± 4.46 µm vs. buccal 25.27 ± 1.16 µm. Whereas erosion-alone resulted in occlusal wear of 1.65 ± 0.13 µm and buccal 1.75 ± 0.03 µm. Microhardness testing at different loads revealed significantly greater hardness reductions in occlusal enamel vs. buccal enamel for 0.1 KgF indentations (P < 0.001) whereas in contrast 0.5 KgF indentations showed no differences. SIGNIFICANCE: Wear simulation with CAD/CAM glass ceramic antagonists produced consistent wear in dental materials and human enamel, regardless of enamel surface origin. Lighter (0.1 KgF) hardness testing of occlusal vs. buccal origin revealed damage to the mechanical integrity of the superficial worn enamel.

The effect of location/site on polished human enamel after mechanical and chemical wear.

OBJECTIVE: To compare profilometry and microhardness of polished occlusal and buccal human enamel following a mechanical and chemical wear regime. METHODS: Enamel from polished human molars were sectioned into buccal and occlusal surfaces and randomly allocated into two groups (n = 10) and then exposed to 0.3 % citric acid at pH 2.7 for 10, 20, 40 and 60 mins each followed by abrasion with non-fluoridated toothpaste for 240 strokes in a reciprocating brushing machine. A white light profilometer with a spot size of 12 um measured mean step-height following each cycle. Microhardness indentations were conducted following the final cycled 60 mins erosion/abrasion using 0.01, 0.02, 0.1, 0.5 and 2.5 kgf indentation load. Statistical disparity were evaluated using a two-way ANOVA and post-hoc Sidak's multiple comparisons tests at α = 0.05. RESULTS: After erosion/abrasion, the mean (SD) step-heights on occlusal and buccal surfaces were not significantly different until 60 mins, when occlusal surfaces exhibited greater step-heights, 32.9 µm (2.8) and 31.1 µm (1.8) and p = 0.02, respectively. Buccal and occlusal microhardness was statistically lower following erosion/abrasion at loads of 0.01 kgf (p = 0.0005) and 0.02 kgf (p = 0.0006) but no significant differences were observed in the microhardness between the surfaces at any loads. CONCLUSION: The occlusal and buccal surfaces were not statistically different for microhardness or step height suggesting the susceptibility to wear is not related to the anatomy and structure of the tooth and is more likely related to other factors such as the environment. CLINICAL SIGNIFICANCE: The study emphasizes that a notable difference in wear between occlusal and buccal enamel surfaces emerges only after prolonged exposure to simultaneous chemical and mechanical stress. This finding necessitates a preventive dental approach that accounts for both the duration of exposure and environmental factors.

Cigarette Smoking and Nicotine Dependence Among Dental Students in Riyadh, Saudi Arabia: A Cross-Sectional Study.

INTRODUCTION: Dental professionals have a vital role in promoting tobacco cessation interventions in dental care settings, and despite being aware of the detrimental effects of tobacco products on individuals' health, they are still engaged in using tobacco products. AIM: The aim of this study was to assess the prevalence of cigarette smoking and the level of physical and social nicotine dependence among undergraduate dental students in Riyadh, Saudi Arabia, using standardized tools to develop appropriate tobacco cessation interventions. METHODOLOGY: Dental students from six dental colleges located in Riyadh, Saudi Arabia, were invited to participate in this study. A total of 430 dental students agreed to participate by providing written informed consent. Physical dependence on nicotine was assessed using the Fagerstrom Test for Nicotine Dependence (FTND), and social dependency was assessed using the Kano Test Social Nicotine Dependence (KTSND). RESULTS: Among the 430 participants, 120 (27%) reported smoking. The level of nicotine dependence assessed for the 120 (27%) participants who had reported smoking using FTND showed 24 (20%) with high nicotine dependence and 18 (15%) with very high nicotine dependence. When compared between the genders, five (16%) of the female participants displayed high nicotine dependency, and two (6%) displayed very high nicotine dependency. Among the male participants, 19 (21%) displayed high nicotine dependency, and 16 (18%) displayed very high nicotine dependency. The study participants also displayed high KTSND scores, male participants with a mean score of 18.20 and female participants with a mean score of 17.97. CONCLUSION: Dental students, despite being the facilitators in tobacco prevention and cessation programs, have displayed a high prevalence of cigarette smoking and nicotine dependence. These findings should be considered for designing specific tobacco cessation programs for dental students, along with effective stress management programs. Emphasis should be placed on developing and implementing policies for creating supportive environments in educational institutions. Dental students should be trained and engaged in tobacco prevention and cessation intervention programs for their patients.

Prevalence and Knowledge of Respiratory Symptoms Among the General Public in the Southern Area of Najran, Saudi Arabia: A Cross-Sectional Health Survey Study.

Objective: To investigate the knowledge, prevalence of chronic respiratory disorders, and utilization of their medications among the adults at Najran region, Saudi Arabia. Methods: An online cross-sectional survey was carried out in Najran region, Saudi Arabia. A self-administered questionnaire was distributed among a random sample of the general population, aged 18 or above between March and December 2022. The survey instrument included questions regarding history and exposure, physician diagnosed-disorders, respiratory symptoms, allergy, use of medications and possible risk-related factors. Results: This research had a total of 712 individuals. Nearly one-third of the participants in the survey (n = 218; 30.6%) said that they or a member of their family suffer from respiratory ailments. The majority of research participants (n = 167; 76.8%) identified asthma as their primary respiratory condition. A total of 32.0% of participants (n = 70) reported dealing with dust or chemicals such as paints, fertilizers, and cleaning products on a daily basis at work or at home. Around 62.0% of the participants (n = 134) said that exposure to gases, fragrances, and other such substances negatively impacts their health. Almost 78.0% (n = 169) of them indicated that summer weather affects their health, whereas 63.0% (n = 138) reported that winter cold affects their health. Participants aged 41-50 years were 38.0% less likely to have CRDs compared to others (p < 0.05). Conclusion: This study is among the first few studies that explored the knowledge, prevalence of chronic respiratory disorders, and utilization of their medications among the adults at Najran region, Saudi Arabia. In the southern area of Najran, respiratory symptoms are frequent among the inhabitants of Saudi Arabia. More research is required to discover avoidable risk factors and create countermeasures for them. It is recommended that healthcare personnel increase their efforts to educate their patients about respiratory illness prevention methods.

Public awareness about glaucoma, cataract, and diabetic retinopathy in Saudi Arabia: a systematic review and meta-analysis.

PURPOSE: To identify the public level of knowledge about the common ophthalmological conditions in Saudi Arabia. METHODS: We searched Medline, Embase, and CENTRAL for relevant literature. We included questionnaire-based cross-sectional studies performed in Saudi Arabia assessing the public awareness and attitude about general knowledge, causes/risk factors, signs/symptoms, disabilities/consequences, and relieving/management measures of the common ophthalmological conditions including glaucoma, cataract, and diabetic retinopathy (DR). The meta-analysis was performed on outcomes reported in ≥ 2 studies utilizing the random-effects model. Quality assessment was done using the Appraisal tool for Cross-Sectional Studies (AXIS) tool. RESULTS: Twenty-eight studies were deemed eligible for inclusion in this review. A total of 72 questions were reported in ≥ 2 studies and were included in the meta-analysis. The total number of participants was 14,408. The meta-analysis estimated that 57.63% (95% confidence interval (CI) 56.87-60.07%), 69.90% (95% CI 67.02-76.07%), and 68.65% (95% CI 65.94-71.23%) of the Saudi public have you ever heard or read about glaucoma, cataract, and DR, respectively. Of the public surveyed in the included studies, 43.68% (95% CI 41.54-45.85%), 55.43% (95% CI 54.03-56.82%), and 63% (95% CI 60.8-65.1%) believed that glaucoma, cataract, and DR could be treated. CONCLUSION: This systematic review showed that the level of knowledge among the Saudi population about the common ophthalmological conditions was the highest with respect to cataract, followed by DR and glaucoma. The areas of unsatisfactory level of awareness about the common ophthalmological conditions included risk factors, signs/symptoms, complications, and management options. These areas need to be addressed appropriately by future educational interventions.

The Knowledge, Attitude, and Perception of Needlestick Injuries Among Dental Students in Riyadh, Kingdom of Saudi Arabia: A Cross-Sectional Survey.

INTRODUCTION: Needlestick injuries (NSIs) represent a significant source of bloodborne viruses in the healthcare sector, particularly in dentistry. Developing effective infection control programs necessitates access to surveillance data. A comprehensive evaluation, encompassing human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), and serological testing, is crucial due to the potential lack of immediate symptoms in infected patients. It is essential to verify hepatitis B and tetanus immunization statuses and seek guidance from infectious disease experts for post-exposure prophylaxis. Aim and objective: This study aims to assess the knowledge, attitudes, and perceptions of NSIs among dentistry students in Riyadh, Saudi Arabia. METHODS: Conducted during the 2023-2024 academic year in Riyadh, Saudi Arabia, this cross-sectional study evaluated the knowledge, attitudes, and perceptions of undergraduate dental medicine students regarding NSIs. Ethical approval was obtained, and informed consent was meticulously collected. Before participation, potential subjects were furnished with a comprehensive information sheet outlining the study's purpose, the survey's nature, expected duration, and potential risks or benefits. The document emphasized their unequivocal right to withdraw from the study at any point without any adverse consequences. Data collection relied on an online survey administered to third and final-year dental students selected from specific universities. This selection criterion ensured that participants were directly relevant to the dental education context under investigation. Careful exclusions were made to minimize potential bias, particularly by excluding students from academic years other than the third and final years, thus maintaining a specific focus on this subgroup. Data analysis primarily compared NSI occurrences and awareness based on dental college and academic year. Detailed findings are presented in the results section. RESULTS: The study unveiled high vaccination rates (95.23%) and significant levels of education regarding bloodborne infections (81.38%) among participants. However, it was noteworthy that 72.72% believed their vaccinations offered complete protection. Only 47.18% believed that wearing surgical gloves reduced the risk of NSIs, while a substantial majority (93.07%) opposed the practice of needle recapping. Moreover, 76.19% demonstrated knowledge of post-exposure prophylaxis, indicating room for improvement in healthcare safety practices. Statistical analysis identified significant associations between the Dental College attended and both NSI occurrence (χ²=12.164, p=0.058) and awareness (χ²=14.629, p=0.023). Conversely, the academic year exhibited no significant relationship with either NSI occurrence (χ²=1.2, p=0.55) or awareness (χ²=0.44, p=0.8). Additionally, the study revealed non-normal distributions for both NSI occurrence (p<0.001) and awareness (p<0.001) among participants. CONCLUSION: In conclusion, this study underscores the pivotal role of awareness in mitigating NSI occurrences among dental students. Irrespective of their academic year, heightened awareness significantly correlated with reduced NSI incidence. These findings bear significant implications for dental education and practice, emphasizing the imperative need for comprehensive education and awareness initiatives to bolster healthcare safety among dental professionals.

Venous Thromboembolism Risk Assessment Models in Plastic Surgery: A Systematic Review and Meta-Analysis.

Postoperative venous thromboembolism (VTE) is the most common complication of plastic surgery procedures. Diverse risk assessment models (RAMs) exist to stratify patients by VTE risk, but due to a lack of high-quality evidence and heterogeneity in RAM data, there is no recommendation regarding RAM that can be used for plastic surgery patients. This study compares the reliability and outcomes of Caprini and American Society of Anesthesiologists (ASA) physical status classification RAMs used in plastic surgery to help surgeons stratify the risk of VTE. Methods: MEDLINE and Embase databases were searched between February 2010 and December 2021. All published English articles that report the incidence of VTE stratified by a RAM among patients who underwent plastic surgery were included. The results of the presented meta-analysis were pooled using a random-effects model. Results: The database search revealed 809 articles, out of which eight studies (n = 1,348,606) were eligible. Out of the eight studies, six utilized the Caprini score, and three utilized ASA score. Super-high-risk patients were significantly more likely to present with VTE than their high-risk [odds ratio (OR), 2.92; 95% confidence interval (CI), 1.26-6.78], medium-risk (OR, 5.29; 95% CI, 2.38-11.79), or low-risk counterparts (OR, 10.00; 95% CI, 2.32-43.10) at Caprini score. High-risk patients in ASA score showed significant increase in VTE incidents (OR, 2.72; 95% CI, 1.10-6.72). Conclusions: Both Caprini and ASA RAMs showed compelling evidence of efficacy in our study. However, the Caprini RAM is more predictive of postoperative VTE incidents in high-risk plastic surgery patients than the ASA grading system.

Peripapillary atrophy classification using CNN deep learning for glaucoma screening.

Glaucoma is the second leading cause of blindness worldwide, and peripapillary atrophy (PPA) is a morphological symptom associated with it. Therefore, it is necessary to clinically detect PPA for glaucoma diagnosis. This study was aimed at developing a detection method for PPA using fundus images with deep learning algorithms to be used by ophthalmologists or optometrists for screening purposes. The model was developed based on localization for the region of interest (ROI) using a mask region-based convolutional neural networks R-CNN and a classification network for the presence of PPA using CNN deep learning algorithms. A total of 2,472 images, obtained from five public sources and one Saudi-based resource (King Abdullah International Medical Research Center in Riyadh, Saudi Arabia), were used to train and test the model. First the images from public sources were analyzed, followed by those from local sources, and finally, images from both sources were analyzed together. In testing the classification model, the area under the curve's (AUC) scores of 0.83, 0.89, and 0.87 were obtained for the local, public, and combined sets, respectively. The developed model will assist in diagnosing glaucoma in screening programs; however, more research is needed on segmenting the PPA boundaries for more detailed PPA detection, which can be combined with optic disc and cup boundaries to calculate the cup-to-disc ratio.

Combining biomedical knowledge graphs and text to improve predictions for drug-target interactions and drug-indications.

Biomedical knowledge is represented in structured databases and published in biomedical literature, and different computational approaches have been developed to exploit each type of information in predictive models. However, the information in structured databases and literature is often complementary. We developed a machine learning method that combines information from literature and databases to predict drug targets and indications. To effectively utilize information in published literature, we integrate knowledge graphs and published literature using named entity recognition and normalization before applying a machine learning model that utilizes the combination of graph and literature. We then use supervised machine learning to show the effects of combining features from biomedical knowledge and published literature on the prediction of drug targets and drug indications. We demonstrate that our approach using datasets for drug-target interactions and drug indications is scalable to large graphs and can be used to improve the ranking of targets and indications by exploiting features from either structure or unstructured information alone.

Pediatric Inflammatory Bowel Disease Associated With Celiac Disease: A Retrospective Study in a Tertiary Care Hospital in Saudi Arabia.

Background. Inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD), is a chronic relapsing disease indicated by inflammation of the gastrointestinal tract. Celiac disease (CeD) is a chronic autoimmune disease of the small bowel. The prevalence of CeD in IBD patients is unknown. Some studies have described the coexistence of the 2 diseases in the same patient. This study aimed to investigate the prevalence of CeD in Saudi Arabian children with IBD. Methods. We used a retrospective study design because data can be collected immediately and is easier to analyze afterward. The study was conducted on IBD patients in the Pediatric Gastroenterology Department at National Guard Hospital, Jeddah, Saudi Arabia. We enrolled Saudi patients aged between 1 and 18 years who had been diagnosed with IBD and CeD based on positive biochemical serology and histology from January 2011 to January 2020. We excluded patients with immunodeficiency disorders. Results. Among the 46 enrolled patients with IBD, CeD was identified in 4, and they did not develop any relapses. We discovered that the weight at IBD diagnosis improved significantly compared to current weight (P-value < .0001). We also discovered that the height at diagnosis of IBD improved significantly compared to the current height (P-value < .0001). Additionally, we found no significant associations between UC and CeD (P-value = 1), or CD and CeD (P-value = .625). Conclusion. No significant associations were evident between the prevalence of CeD and IBD. More prospective multicenter studies are needed to clarify the prevalence of CeD in children with IBD.

Flexural Strength, Elastic Modulus and Remineralizing Abilities of Bioactive Resin-Based Dental Sealants.

OBJECTIVE: To assess the remineralizing abilities and compare the flexural strength and elastic modulus of different bioactive pit and fissure sealants. MATERIALS AND METHODS: Human enamel samples were randomly and blindly sealed with one of the following bioactive materials: BioCoat (Bc), ACTIVA KIDS (Av) and BeautiSealant (Bu). Seal-it (Si) was used as a non-bioactive sealant beside a control blank (B) group with no sealant. The sealed samples were subjected to a pH-cycling model (7 days of demineralization-remineralization cycles). The enamel surface hardness change (SHC), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) and polarized light microscopy were used to assess the remineralizing abilities of the studied sealants. Flexural strength and elastic modulus were also assessed following the ISO 4049 protocols. One-way analysis of variance (ANOVA) was used to analyze the results. RESULTS: Bc sealant showed the highest FS and EM (p < 0.05). The contact with Bc and Bu sealants showed significantly lower %SHL (p < 0.05) in comparison to the other. These findings were supported by the results of SEM-EDX and polarized imaging by showing higher percentages of calcium and phosphate ions with the former sealants and thinner demineralized enamel bands. CONCLUSION: In this study, Bc showed the highest flexural strength. Bc and Bu sealants outperformed the other studied sealants in terms of their remineralization abilities.

Therapeutic effect of localized vibration on alveolar bone of osteoporotic rats.

OBJECTIVES: Vibration, in the form of high frequency acceleration (HFA), stimulates alveolar bone formation under physiologic conditions and during healing after dental extractions. It is not known if HFA has an anabolic effect on osteoporotic alveolar bone. Our objective is to determine if HFA has a regenerative effect on osteoporotic alveolar bone. METHODS AND MATERIALS: Adult female Sprague-Dawley rats were divided into five groups: 1) Ovariectomized Group (OVX), 2) Sham-OVX Group that received surgery without ovariectomy, 3) OVX-HFA Group that was ovariectomized and treated daily with HFA, 4) OVX+Static Force Group that was ovariectomized and received the same force as HFA, but without vibration, and 5) Control Group that did not receive any treatment. All animals were fed a low mineral diet for 3 months. Osteoporosis was confirmed by micro-CT of the fifth lumbar vertebra and femoral head. HFA was applied to the maxillary first molar for 5 minutes/day for 28 and 56 days. Maxillae were collected for micro-CT, histology, fluorescent microscopy, protein and RNA analysis, and three-point bending mechanical testing. RESULTS: Micro-CT analysis revealed significant alveolar bone osteoporosis in the OVX group. Vibration restored the quality and quantity of alveolar bone to levels similar to the Sham-OVX group. Animals exposed to HFA demonstrated higher osteoblast activity and lower osteoclast activity. Osteogenic transcription factors (RUNX2, Foxo1, Osterix and Wnt signaling factors) were upregulated following vibration, while RANKL/RANK and Sclerostin were downregulated. HFA did not affect serum TRAcP-5b or CTx-1 levels. The osteogenic effect was highest at the point of HFA application and extended along the hemimaxillae this effect did not cross to the contra-lateral side. CONCLUSIONS: Local application of vibration generated gradients of increased anabolic metabolism and decreased catabolic metabolism in alveolar bone of osteoporotic rats. Our findings suggest that HFA could be a predictable treatment for diminished alveolar bone levels in osteoporosis patients.

Age-dependent biologic response to orthodontic forces.

INTRODUCTION: Orthodontic tooth movement results from increased inflammation and osteoclast activation. Since patients of all ages now routinely seek orthodontics treatment, we investigated whether age-dependent biologic responses to orthodontic force correlate with the rate of tooth movement. METHODS: We studied 18 healthy subjects, adolescents (11-14 years) and adults (21-45 years), with Class II Division 1 malocclusion requiring 4 first premolar extractions. Canines were retracted with a constant force of 50 cN. Gingival crevicular fluid was collected before orthodontic treatment and at days 1, 7, 14, and 28 after the canine retraction. Cytokine (IL-1ß, CCL2, TNF-α) and osteoclast markers (RANKL and MMP-9) were measured using antibody-based protein assays. Pain and discomfort were monitored with a numeric rating scale. The canine retraction rate was measured from study models taken at days 28 and 56. RESULTS: Although the cytokine and osteoclast markers increased significantly in both age groups at days 1, 7, and 14, the increases were greater in adults than in adolescents. Interestingly, the rate of tooth movement in adults was significantly slower than in adolescents over the 56-day study period. Adults also reported significantly more discomfort and pain. CONCLUSIONS: Age is a significant variable contributing to the biologic response to orthodontic tooth movement. Adults exhibited a significantly higher level of cytokine and osteoclasts activity but, counterintuitively, had a significantly slower rate of tooth movement.