AL-Alawi H, et al. Restor Dent Endod. 2019 Nov;45:e1. https://doi.org/10.5395/rde.2020.45.e1

Studies evaluating dental assistants’ knowledge about tooth avulsion and its management are rare. The purpose of this study was to evaluate the level of knowledge about tooth avulsion and its management among dental assistants in Riyadh, Saudi Arabia and to assess its relationship with their educational background.

There is a lack of adequate information on dentists’ knowledge about tooth avulsion and its management in Saudi Arabia. The aim of this study was to evaluate the level of knowledge about permanent tooth avulsion and its management among dentists working in Riyadh, Saudi Arabia. A total of 550 dentists were contacted to request their participation in this 19-item questionnaire survey over a three-month period starting in January 2015 using convenience sampling methodology. A questionnaire consisting of demographic items and multiple-choice questions regarding knowledge of avulsion and its management was used. The level of knowledge was assessed using a scoring system that assigned one point for each correct answer and zero points for wrong answers, with a maximum possible score of ten points. An independent t-test was used to compare the level of knowledge (mean score) based on particular variables, such as sex, nationality, type of practice, current employment, working hours and whether the respondents had attended a continuing dental education (CDE) programme on avulsion management. The level of significance was set at P< 0.05. A total of 470 completed questionnaires were collected with data suitable for statistical analysis. The majority of the respondents were Saudi (n = 331; 72.1 %) and general practitioners (n = 278; 59.3 %). Most of the participants correctly responded to the knowledge-based questions, except the questions regarding the best storage medium (milk: 24.1 %) and the duration of follow-up by clinical and radiographic examination (5 years: 15.6 %). The mean knowledge score was 5.94 ± 1.57. Gender (P = 0.001), current employment (P = 0.045) and working hours per day (P = 0.020) had a significant effect on the mean knowledge score. The surveyed dentists were found to have a moderate knowledge of avulsion and its management, although a relative lack of knowledge was observed regarding the duration of follow-up after replantation.

Background Vacuum-formed retainer (VFR) is the most used retainer due to its higher aesthetic properties and lower cost, their mechanical properties of are important in determining the stability and long-term use of appliances made out of them. Aim: This study aimed to evaluate and compare the flexural modulus, surface hardness, and color stability of three different VFR materials. Methods: Three different VFR materials, namely Duran, Keystone, and Zendura, of 1 mm thickness, were tested after thermoforming for flexural modulus, hardness, and color stability. They were formed over a stainless-steel model of 12 mm diameter and 6 mm height. Results: There were significant statistical differences (p = 0.000) in the flexural modulus and hardness of the three materials. Regarding color stability, Zendura exhibited significantly higher ΔE* values than Keystone and Duran (p < 0.05). Conclusions: Zendura had the highest flexural modulus and hardness compared with Duran and Keystone; however, it is more susceptible to color change compared to the other tested materials.

Background: The language of EFL learners is of special interests to linguists. Little research has been tackled on issues concerning English Discourse Markers (EDMs) among Saudi EFL learners. Aims: Employing a corpus-based descriptive analysis, the current study attempts at detecting EDMs in the talk of Saudi EFL learners, their frequency, use, usage, etc., in comparison to other EFL learners as well as native speakers. Methods: Two hundreds Saudi EFL learners were randomly selected from 20 public and private schools (ten students from each school) across the Kingdom of Saudi Arabia (KSA). Subjects were individually recorded while they were studying English in class. Recordings were then linguistically and statistically analyzed by the researchers. Conclusion: Results illustrate that EDMs “and”, “but” and “also” are the most frequent EDMs in the talk of Saudi EFL learners. These devices are randomly used by Saudi EFL learners who mix their use (appropriateness) with usage (correctedness) due to the influence of their L1 (Arabic). In compare to other EFL learners (native and non-native), Saudi EFL learners use less EDMs. These results confirmed the claims that EFL learners use EDMs less than native speakers. This paper, although preliminary in nature, can help arrive a better understanding of using EDMs by Saudi EFL learners. Further, it can also assist in getting appropriate insights into the way how these EDMs are used in Arab Gulf countries. The researchers decided to conduct an in-depth study into the use of EDMs in the oral work of Saudi EFL learners.

The quasi‐Lindley distribution is a flexible model useful in reliability analysis, management science, and engineering analysis. In this paper, an expectation‐maximization (EM) algorithm was applied to estimate the parameters of this model for uncensored and right‐censored data. Simulation studies show that the estimates of EM perform better than maximum likelihood estimates (MLEs) for both uncensored and censored data. In an illustrative example, the waiting times of a bank’s customers are analyzed and the estimator of the EM algorithm is compared with the MLE. The analysis of the data can be useful for the management of the bank.