Abdullah G. Amran

Bio: Abdullah G. Amran is an academic researcher from Thamar University. The author has contributed to research in topics: Medicine & Population. The author has an hindex of 6, co-authored 15 publications receiving 122 citations.

Use of Zirconia in Dentistry: An Overview

Abstract: Due to an increasing interest in esthetics and concerns about toxic and allergic reactions to certain alloys, zirconia was proposed as a new ceramic material in the later part of 20 th century. It has become a popular alternative to alumina as biomaterial and is being used in dental applications for fabricating endodontic posts, crown and bridge restorations and implant abutments. It has also been applied for the fabrication of esthetic orthodontic brackets. This article presents a brief history, dental applications and new methods for fabrication of zirconia improving its mechanical properties. Additionally, the bonding between zirconia and resin cements as well as conventional cementation has been discussed. The methods of the improvement of the bonding strength have also been highlighted.

Determination of occlusal vertical dimension for complete dentures patients: an updated review.

Abstract: Determination of the occlusal vertical dimension (OVD) is an integral part of complete dentures fabrication Due to the lack of teeth, the clinician faces the challenge of how to accurately establish the OVD of the new denture Therefore, the purpose of this review article was to present, discuss and critique the available methods used in determining the OVD for complete dentures patients This review identified two main streams to determine the OVD: (i) pre-extraction methods and (ii) post-extraction methods For the pre-extraction methods, the OVD of the natural dentition is transferred to the new dentures mainly by intra-oral measurements, profile tracing and cephalometric analysis The post-extraction methods rely on mandibular rest position, facial aesthetic appearance, swallowing pattern, craniofacial landmarks measurements, cephalometric analysis, phonetics and existing dentures In general, all the available techniques have merits and are helpful for routine clinical use However, they are empirical in nature, controversial and lack the scientific support Further, there is no single accurate method for OVD determination To overcome the limitations of the techniques, the clinician will benefit from applying combination of techniques to approximate the OVD

Translation and validation of the Arabic version of the 5-item Oral health impact profile: OHIP5-Ar.

Abstract: The aim of this study was to translate and validate an Arabic version of the 5-item Oral Health Impact Profile (OHIP). A total of 320 subjects (aged 18 years and above) were consecutively recruited from dental clinics. The self-administered OHIP5-Ar was distributed and the data were collected and analyzed. The dimensionality of the instrument was investigated using confirmatory factor analyses (CFA). Reliability was assessed as the instruments internal consistency using Cronbach’s alpha and test-retest-reliability using intraclass correlation coefficient (ICC). Convergent validity was tested by correlation between perceived global oral and general health questions with the latent factor (OHRQoL) using structural equation modelling analysis and with OHIP5-Ar total score using spearman’s correlation coefficient. Known-groups validity was tested among groups with known differences and sensitivity to change was also investigated after dental treatments. The OHIP5-Ar was fitted well in the unidimensional model as indicated by the CFA with fit indices (RMSEA: 0.00, SRMR: 0.010, GFI: 0.998, TLI: 1). Cronbach’s alpha was 0.78 and the ICC agreement was 0.88. The validity tests indicated satisfactory validity of the instrument and the sensitivity to change of the instrument revealed significant change in the OHIP5-Ar total score after the provision of dental treatments (effect sizes: 0.55–1.49). The OHIP5-Ar showed satisfactory psychometric properties among Arabic-speaking population. This instrument is sensitive to the changes of oral health and can be used to measure the OHRQoL with one total score.

Eye-rima oris distance and its relation to the vertical dimension of occlusion measured by two methods: Anthropometric study in a sample of Yemeni dental students.

Abstract: Objective: This study was conducted to evaluate the relationship between the distance measured from the distal outer of the eye to the parting line of the lips and the occlusal vertical dimension (OVD) measured by two methods. Methods: One hundred and fourteen dental students (76 males and 38 females) were recruited for this study with mean age (22.34 ± 1.83) years. The distance from distal canthus of the eye to rima oris (eye-RO) was compared with two different measurements of the OVD (nasal [N] to gnathion [Gn], and subnasal [Sn] to menton [Me]). All distances were measured using modified digital caliper.Results: Pearson correlation coefficient test for correlations and paired samples t-test for differences were used with a significant level of (P < 0.05). There was a positive significant correlation between the eye-RO distance and the two measurements of the OVD. However, this correlation was stronger between eye-RO and the distance from the tip of the nose to the tip of the chin than that between eye-RO and the distance from the septum of the nose to the under of the chin (r = 0.313 with P = 0.0007, r = 0.296 with P = 0.0014), respectively. Conclusion: The distance from the outer canthus of the eye to the parting of the lips seems to be a reliable method in predicting the OVD and should relate to the distance from the tip of the nose to the tip of the chin.

Optical properties of zirconia ceramics for esthetic dental restorations: A systematic review.

Abstract: Statement of problem Yttria-stabilized tetragonal zirconia polycrystal has been used as a dental biomaterial for several decades because the fracture toughness and bend strength are increased by a stress-induced transformation-toughening mechanism. However, its esthetics are compromised by its poor translucency and grayish-white appearance. Purpose The purpose of the present systematic review was to assess information on the mechanical, chemical, and optical requirements of monolithic zirconia dental restorations. Material and methods The following databases (2010 to 2015) were electronically searched: ProQuest, EMBASE, SciFinder, MRS Online Proceedings Library, Medline, Compendex, and Journal of the American Ceramic Society. The search was limited to English-language publications, in vitro studies, experimental reports, and modeling studies. Results The data from 57 studies were considered in order to review the intrinsic and extrinsic characteristics of zirconia and their effects on the optical properties. Conclusions The materials and microstructural issues relevant to the esthetics and long-term stability of zirconia have been considered in terms of monolithic restorations, while there also are restorations specifically for esthetic applications. Although zirconia-toughened lithium silicate offers the best esthetic outcomes, transformation-toughened zirconia offers the best mechanical properties and long-term stability; cubic stabilized zirconia offers a potential compromise. The properties of these materials can be altered to some extent through the appropriate application of intrinsic (such as, annealing) and extrinsic (such as, shade-matching) parameters.

The prevalence of dental anxiety and fear in patients referred to Isfahan Dental School, Iran

Abstract: Background: Dental anxiety and fear are major complications for both patient and dental care provider. The purpose of this study was to assess the prevalence of dental anxiety and fear in patients who referred to Isfahan Dental School and their relation to their age, gender, educational level, past traumatic experiences and frequency of dental visits. Materials and Methods: In this cross-sectional study, 473 patients were provided with a questionnaire including three sections. First section contained questions concerning their age, gender, educational level, frequency of dental visits, reasons for irregular attendance and existence of past traumatic experiences. Second section comprised a Farsi version of Modifi ed Dental Anxiety Scale (MDAS); and third included a Farsi version of dental fear survey (DFS). Data were analyzed by t-test, ANOVA, Pearson and Spearman correlation tests. Results: The prevalence of dental anxiety among the study population was 58.8%. No correlation was found between age and MDAS (r = −0.08, P = 0.07) and DFS (r = −0.03, P = 0.53). Women demonstrated higher anxiety (P < 0.001) and fear (P = 0.003). Education had no signifi cant effect on dental anxiety (r = −0.046, P = 0.32) and dental fear (r = −0.017, P = 0.79). Previous traumatic experiences were found to result in elevated anxiety and fear (P < 0.001). There was an inverse relationship between frequency of dental attendance and anxiety (r = −0.128, P = 0.008). Conclusions: Within the limitations of this study, anxiety associated with dental treatment was widespread in the study population. Dental fear and anxiety were not affected by age or education level. Dental fear and anxiety were higher in women. In addition, people who visited the dentist more regularly and individuals without previous traumatic dental experiences were less anxious. Key Words: Dental anxiety, dental fear, dental treatment, prevalence, sociodemographic data

Impact of tooth wear on daily living

Abstract: Tooth wear had an adverse effect on several aspects of patient satisfaction.

Psychometric Properties of the Croatian version of the Orofacial Esthetic Scale

Abstract: Objectives: To develop a Croatian version of the Orofacial Esthetic Scale (OES) and test the psychometric properties. Methods: OES is the 8- item instrument for measuring self-reported orofacial esthetics in patients with prosthodontics concerns. The questionnaire was designed to be used as a stand-alone instrument to measure direct esthetic impacts. The English version of the OES (0-10) was translated into Croatian language according to the accepted methods(forward-backward method). The original 11 point scale, as well as the 5 point scale (1=unsatisfactory, 5=excellent) were used. Convergent validity was tested on 126 subjects, and discriminative validity on the same subjects divided into 4 groups: patients esthetically normal (n=25), patients esthetically impaired (n=42), controls esthetically normal (n=37), and controls esthetically impaired (n=22). Test-retest reliability was tested on 43 subjects. Responsiveness was tested on 32 esthetically impaired patients (P-EI) who received prosthodontic treatment. Results: Additional explanation was added to the first two items of the OES. Convergent validity was confirmed by the association between the OES scores and the self- reported oral esthetics and the 3 OHIP questions related to esthetics (correlation coefficients ranged from 0.734 to 0.811, P 0.05). The 0-10 OES scale showed significant differences for the third and the eighth question (P<0.01). Internal consistency showed high Cronbach α (0.802-0.962). Responsiveness was confirmed by a significant difference between the baseline and follow-up (P<0.001) and a high effect size. Conclusions: Psychometric properties of OES-CRO render the instrument suitable for the assessment of esthetics in Croatia.We recommend changing the first two items by adding explanation that questions are related to the lower third of the face and the five point scale for rating.