Role of Natural Cross Linkers in Resin–Dentin Bond Durability: A Systematic Review and Meta-Analysis

Background: The role of endogenous Matrix Metallo Proteinases in resin dentin bond deterioration over time has been well documented. The present study aimed to systematically review the literature; in vitro and ex vivo studies that assessed the outcomes of natural cross-linkers for immediate and long-term tensile bond strength were included. Methods: The manuscript search was carried out in six electronic databases—PubMed/MEDLINE, LILACS, SciELO, Cochrane, Web of Science and DOAJ, without publication year limits. Only manuscripts in English (including the translated articles) were selected, and the last search was performed in December 2020. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement was followed. Results: From the 128 potentially eligible studies, 48 full-text articles were assessed for eligibility. After eligibility assessment and exclusions, 14 studies were considered for systematic review and seven studies for meta-analysis. Amongst the selected studies for meta-analysis, three had a medium and four had a low risk of bias. Conclusions: It was evidenced by the available data that Proanthocyanidin is the most efficient natural cross-linker to date, in preserving the bond strength even after ageing

Longevity and failure mode of posterior ceramic crowns and fixed partial denture

The purpose of this review is to analyse the longevity of posterior all-ceramic crowns and fixed partial dentures; in addition to determine the failure mode. It seeks to assess the risk factors that should be considered with posterior all-ceramic restorations. The review of literature revealed an acceptable longevity for posterior all-ceramic restorations in a 5-year follow up period. This accompanies their aesthetic outcome especially with improving of mechanical properties of glass ceramic by adding reinforcement crystalline phases or using core. The loss of vitality and secondary caries were the common biological complications while ceramic fracture and chipping were the most frequent mechanical complications. Also, the para-functional activity and using implant as an abutment increase the risk of failure especially on posterior teeth

Ocular Findings in Patients with Orbital Fractures: A 1-Year Prospective Study in a Tertiary Center

Background and Objectives: The aim of this study was to study the prevalence of ocular findings in patients with orbital fractures in a tertiary center in Saudi Arabia. Materials and methods: A cross-sectional observational study was performed. The participants were patients who presented with orbital trauma to the emergency department of King Saud Medical City (Riyadh, Saudi Arabia). Subjects included those diagnosed with isolated orbital fracture using clinical evaluation and CT examination. We performed direct evaluation of ocular findings for all patients. Variables studied included age, gender, site of ocular fracture, cause of trauma, side of fracture, and ocular findings. Results: In total, 74 patients with orbital fractures were included in this study (n = 74). Of the 74 patients, 69 (93.2%) were males and only 5 patients (6.8%) were females. The age range was 8-70 years, with a median age of 27 years. The 27.5–32.6-year age group was the most affected (95.0%). The left orbital bone was involved in the majority of bone fractures 48 (64.9%). The orbital floor (n = 52, 41.9%) and lateral wall (n = 31, 25.0%) were the most prevalent sites of bone fracture among the study patients. Road traffic accidents (RTAs) were the most common causes (64.9%) of orbital fractures, followed by assaults (16.2%) and then sports injuries and falls (9.5% and 8.1%, respectively). Animal attacks were the least cause of trauma (only 1 patient, 1.4%). The occurrence of ocular findings, either alone or in combination, showed that subconjunctival hemorrhage had the highest percentage (52.0%), followed by edema (17.6%) and ecchymosis (13.6%). A statistically significant correlation was reported between the site of bone fracture and orbital findings, with r = 0.251 * and p Conclusions: Subconjunctival bleeding, edema, and ecchymosis were the most frequent ocular abnormalities, in that order. There were a few instances of diplopia, exophthalmos, and paresthesia. Other ocular discoveries were incredibly uncommon. The location of bone fractures was found to be significantly correlated with ocular results

Endodontic Clinical Diagnostic Skills amongst Undergraduate Dental Students: Cross-Sectional Study

The purpose of the study was to evaluate the clinical endodontic diagnostic skills amongst undergraduate dental students at pre-clinical and clinical levels at Cardiff University School of Dentistry. An online questionnaire containing eight questions about endodontic diagnosis and hypothetical clinical scenarios was sent to all year 3rd, 4th, and 5th-year undergraduate dental students who were divided into G1, G2, and G3 groups. The data were analysed descriptively and reported in percentages. Around 121 students out of 226 responded to the questionnaire with a response rate of 53.5%. The overall correct response from G1 (3rd year) was 31.6% to 65.8%, G2 (4th year) was 73% to 93%, and G3 (5th year) was 73.2% to 92.7%. The study concludes that the 4th and 5th-year undergraduate dental students’ responses to the hypothetical clinical scenarios were higher than the 3rd-year students. However, regarding questions about the endodontic diagnosis, the percentages of correct answers were similar among all the 3rd, 4th, and 5th-year students. Therefore, further studies assessing endodontic diagnostic skills amongst the same cohort of students during their progression in the undergraduate course are recommended

Analysis of student achievement scores via cluster analysis

In education, the overall performance of every student is an important issue when assessing the quality of teaching. However, in the traditional educational system not all students have the same opportu nity to develop their academic skills in an efficient way. Different teaching techniques have been proposed to adapt the learning process to the stu dent profile. In this work, we analyze the profile of students according to their performance on academic activities and taking into account two dif ferent evaluation systems: work-based assessment and knowledge-based assessment. To this aim, data was collected during the fall semester of 2019 from a physics course at Universidad Loyola Andaluc´ıa, in Seville, Spain. In order to study the student profiles, a clustering approach com bined with supervised feature selection was applied. Results suggest that two student profiles are clearly distinguished according to their perfor mance in the course in both evaluation approaches. These two profiles correspond to students that pass and fail the course. The output of the analysis also indicates that there are redundant and/or irrelevant fea tures. Therefore, machine learning techniques may be helpful for the design of effective activities to enhance the student learning process in this physics course