Ayman aldharrab | King AbdulAziz University (KAU) Jeddah, Saudi Arabia (original) (raw)

Papers by Ayman aldharrab

Journal of Biomaterials and Tissue Engineering

The study examines the microhardness of five ceramic materials using CAD-CAM technology. Twenty-f... more The study examines the microhardness of five ceramic materials using CAD-CAM technology. Twenty-five disc-shaped specimens for the study, using I.P.S. Empress CAD (fully sintered), I.P.S. e.max CAD (30 minutes) and Vita Suprinity (26 minutes) milled in a pre-crystallized stage, Coprasmile (8 hours), and Zenostar milled in partially sintered stage (9 hours and 50 minutes). Each specimen had ten indentations, with a 1000-gram load applied for 10 seconds using a Vickers diamond indenter. Vickers values were automatically converted to microhardness using the formula Hv = 1.8544×F/d2. IBM SPSS 26 for statistical analysis, calculating microhardness values for each group. One-way ANOVA and Tukey HSD posthoc test compared differences between ceramic groups at a P <0.05 significance level. Results showed significant differences among the means (P <0.05), with Coprasmile, Zenostar, and Suprinity groups having the highest and lowest values, respectively.

The International journal of prosthodontics

The aim of this study was to quantify the frequency of positive radiographic findings in edentulo... more The aim of this study was to quantify the frequency of positive radiographic findings in edentulous arches. Panoramic radiographs from 271 patients who were edentulous in one or both arches were evaluated for the presence of retained root fragments, impacted teeth, foreign bodies, radiolucencies, radiopacities, mental foramina at or near the crest of the residual alveolar ridge, and maxillary sinus proximity to the crest of the residual alveolar ridge. One or more of these radiographic observations were found in 51.7% of the examined films. The most frequent finding (30.6%) was close approximation of the maxillary sinus to the crest of the ridge. These results underscore the importance of panoramic examination of edentulous patients in detecting potential problems before complete denture treatment. However, prescribing such an examination in patients seeking replacement dentures requires a thorough patient history and clinical examination.

The Journal of Contemporary Dental Practice, 2013

Objective: To study the effect of three energy drinks on the color stability of nanofilled compos... more Objective: To study the effect of three energy drinks on the color stability of nanofilled composite resins after different periods of aging time. Materials and methods: Composite resin disks, 6 mm diameter, 3 mm thickness were prepared from Filtec Z350 XT, Tetric EvoCeram, and Filtec Z250 XT. Specimens from each material were tested after aging with Red Bull, Bison and Power Horse energy drinks and distilled water as a control. Specimens were stored at 37°C in dark containers for 1, 7, 30 and 60 days. Color was assessed in the CIELAB using a colorimeter before and after each storage period. Color differences E* ab and b* among specimens were measured. Mean values were statistically analyzed using one-way analysis of variance (ANOVA), with p < 0.05 as significance level. Results: The color change E* ab and b* occurred by Red Bull, Bison and Power Horse energy drinks was significantly different for all tested materials at all four times p < 0.05 except in the Red Bull group. All specimens showed increase in color changes toward yellowness b* after a period of 1, 7, 30 and 60 days. The highest total color difference E* ab was found in the Red Bull group after 60 days. Conclusion: Energy drinks used in this study had staining effect on the tested composite resin materials. The discoloration increased with aging time toward yellowness; however, it was not perceptible in all test groups after 60 days.

Egyptian Dental Journal, 2013

Title: Influence of types of curing lights on Shade stability of nano-filled Dental Restorations.... more Title: Influence of types of curing lights on Shade stability of nano-filled Dental Restorations. Aim and Objective: This study is to investigate the variation in shade of nano-filled resin composite restorations cured with QTH and LED light curing systems and evaluating the color stability in response to the beverages as an aging medium. Materials and Methods: In this in-vitro study four different restorative materials were exposed to QTH and LED light curing systems. Ten specimens were prepared for each curing light. Ten specimens were prepared from each material for each type of light cure system. Teflon moulds (Figure 1), measuring 6mm internal diameter by 3mm height will be used to produce the specimens. Shade was examined by VITA digital easyshade guide 3 times before and after curing for each sample mould. Specimens will be stored in an incupator for 24 hours before aging in beverages ( Tea, Coffee, Karkaday, Yansoon). Following these 5 specimens from each material cured with...

Advances in Medical Education and Practice, 2015

This longitudinal study was aimed to investigate the association between didactic grades and prac... more This longitudinal study was aimed to investigate the association between didactic grades and practical skills for dental students and whether didactic grades can reliability predict the dental students' practical performance. Materials and methods: Didactic and practical grades for graduates from the Faculty of Dentistry, King Abdulaziz University, between the years 2009 and 2011 were collected. Four courses were selected: Dental Anatomy, Operative Dentistry, Prosthodontics, and Orthodontics. Pearson product-moment correlation analyses between didactic and practical scores were conducted. Results: There was only a significant correlation between didactic and practical scores for the Dental Anatomy course (P,0.001). There was also a significant correlation between all four subjects in the didactic scores (P,0.001). Only the scores of male students showed a significant correlation in the Operative Dentistry course (P,0.001). There were no correlations between Orthodontic grades. Moreover, a poor degree of reliability was found between didactic and practical scores for all subjects. Conclusion: Based on the findings of this study, the relationship between didactic grades and practical performance is course specific. Didactic grades do not reliably predict the students' practical skills. Measuring practical performances should be independent from didactic grading.

Saudi medical journal, 2012

To evaluate hepatitis B virus (HBV) vaccine coverage and the use of infection control among denti... more To evaluate hepatitis B virus (HBV) vaccine coverage and the use of infection control among dentists in Saudi Arabia. This cross-sectional study was carried out during the Third International Conference at the King Abdulaziz University Faculty of Dentistry, held on March 2012 in Jeddah, Saudi Arabia. Saudi or expatriate dentists working in Saudi Arabia were included in the study. The questionnaires were designed to meet the objective of the study. A total of 402 dentists of whom 176 (44%) were male and 226 (56%) female took part in this study. Their mean age was 37.4 years. In all, 246 (61%) were general dentists and 156 (39%) specialists. Four-fifths (80.5%) of them had been vaccinated. Almost half (48.5%) had experience of needle stick injury, but none reported having been infected with HBV. Among the vaccinated dentists, 186 (57.5%) had not been screened for HBV antibodies. Younger dentists were more particular about vaccination and more careful in using protective wear. There wa...

ISRN Dentistry, 2013

Objective. This study aimed to evaluate the effect of different storage solutions that simulate a... more Objective. This study aimed to evaluate the effect of different storage solutions that simulate acidic, alkaline, and sebum conditiions on the physical properties of pigmented (colorant elastomer) cosmesil M511 maxillofacial prosthetic material.Materials and Methods. Sixty specimens were prepared according to the manufacturer's instructions and were tested before and after immersion of different storage conditions for six months at 37 °C. The following tests were performed: color changes (group I), solution absorption (group II), surface roughness (group III), and scanning electron microscopy (group IV).Results. There were no significant changes observed in the color and solution absorption tests while surface roughness revealed significant difference between control group and other testing storage medium groups, and this result was supported by SEM analysis that revealed limited surface changes.Conclusions. Cosmaseil material is an acceptable cross-linked formulation that withs...

2013 International Conference on Computer Medical Applications (ICCMA), 2013

During the past few decades, unalloyed titanium has been extensively used as a material of dental... more During the past few decades, unalloyed titanium has been extensively used as a material of dental implant-supported restorations but it cause gingival discoloration and unnatural appearance of the surrounding soft tissue. Currently, yttrium oxide partially-stabilized zirconia (Y-TZP) is a ceramic of special interest because of its superior mechanical properties. This study was carried out with four one piece zirconium implants embedded on a standard acrylic resin mandibular edentulous model, the abutment of zirconium implant was classified into two designs and then laboratory test was applied with proposed biting force (sensor (BS) and a bidirectional transmitreceive module. Our study concluded that the use of one piece Zirconium implant with box or parallel shape abutment head in implant supported over-denture without a need of cement, screws or plastics or metal housing for attachment in other types of implant had a superior results and easier maintenance and repair of the prosthesis if any complications occur.

The Journal of Prosthetic Dentistry, 2014

Statement of problem. Surface roughness and internal porosity are 2 potential risk factors that t... more Statement of problem. Surface roughness and internal porosity are 2 potential risk factors that threaten the biocompatibility and long-term mechanical stability of cast partial removable dental prostheses frameworks. Purpose. The purpose of this study was to investigate the influence of the material, of conventional wax patterns, and the recently introduced light-polymerized patterns on the initial surface roughness and internal porosity of the cobalt-chromium castings of partial removable dental prostheses. Material and methods. Twenty-eight identical partial removable dental prosthesis frameworks were fabricated on a cast of a maxillary Kennedy Class III modification 1 partially edentulous patient. Fourteen frameworks were fabricated from each pattern material. The initial surface roughness, Ra (mm), of the resultant castings was measured with a profilometer. Radiographs of the castings were made on dental occlusal films with a dental x-ray unit with the following exposure conditions: tube voltage 70 kV; exposure time 1.0 seconds; tube current 7 mA; and source-film distance 35 cm. The number and size of porosities in the 3 main components (clasp units, major connectors, denture base meshwork) were assessed. Statistical analysis was conducted with the independent sample t test for surface roughness and the Mann Whitney test for internal porosity (a¼.05). Results. The statistical analysis of mean surface roughness and internal porosity revealed no significant difference between the 2 groups. Conclusions. The surface roughness and internal porosity of frameworks fabricated from conventional wax and Liwa patterns were comparable, with no significant differences between the 2 pattern materials.

Advances in medical education and practice, 2013

The objective of this study is to investigate the correlation between the psychomotor skills and ... more The objective of this study is to investigate the correlation between the psychomotor skills and the academic performance of dental students. Didactic and preclinical scores were collected for students who graduated from the Faculty of Dentistry, King Abdulaziz University, Jeddah, Saudi Arabia, in 2011. Three courses (Dental Anatomy, Removable Prosthodontic Denture, and Orthodontics) were selected. Correlations comparing didactic and practical scores were done for the total samples, then for the males and females separately. There was no significant correlation between the practical and didactic scores for the three courses for the total sample. There was a significant correlation between all three subjects in the didactic scores. For females, the results showed that there was only a significant correlation between the practical and didactic scores for Dental Anatomy. For males, no correlation was observed between the practical and didactic scores for all subjects. In the present sa...