Hassan M. El-Shamy has completed his Ph.D. in Conservative Dentistry in 2008 from Ain Shams University, Egypt. He is assistant professor of operative dentistry at King Abdulaziz University, Saudi Arabia since 2011. He was a research... more
Hassan M. El-Shamy has completed his Ph.D. in Conservative Dentistry in 2008 from Ain Shams University, Egypt. He is assistant professor of operative dentistry at King Abdulaziz University, Saudi Arabia since 2011. He was a research assistant at University of Toronto, Faculty of Dentistry in 2008. He has published more than 4 papers in reputed journals. He shared in 88th, 89th and 90th general sessions of IADR/AADR as a presenter as well as several other international conferences. He is a member of Academy of Operative Dentistry, member of International Association for Dental Research IADR and member of Egyptian Dental Union. Polymerization shrinkage effect on proximal contact tightness of composite restorations
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This survey investigated bonding system type and composite application rationale by senior dental students at a dental school in Saudi Arabia. Eighty-three questionnaires with 15 open and closed questions were randomly distributed to... more
This survey investigated bonding system type and composite application rationale by senior dental students at a dental school in Saudi Arabia. Eighty-three questionnaires with 15 open and closed questions were randomly distributed to final year dental students about the use of etch and rinse versus self-etch adhesives and application techniques for posterior resin composite. Data were collected, and statistical analysis was done using Chi-square test (0.05) with two factors "question answer" and "gender." For all questions, the impact of gender was statistically nonsignificant (P > 0.05). Etch and rinse adhesive was significantly (P > 0.05) favored by students with majority do not perform selective etching, use intermittent air for drying tooth structure, apply a single layer bonding agent and thin it by air, cure it for 20 s with the curing tip at close proximity to the cavity, use incremental application technique for composite restorations, cure it for 4...
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This review aims to determine the prevalence and severity of oral health diseases in the Africa and Middle East region (AMER). The profile of oral diseases is not homogeneous across the AMER. There are large disparities between groups.... more
This review aims to determine the prevalence and severity of oral health diseases in the Africa and Middle East region (AMER). The profile of oral diseases is not homogeneous across the AMER. There are large disparities between groups. Reliable data are scarce. The prevalence and severity of oral diseases appear to be increasing in the African region, as does associated morbidity. There are substantial differences in inequalities in oral health. Dental caries prevalence is less severe in most African countries than in developed countries, but the high rate of untreated caries reflects the limited resources available and difficulties of access and affordability to essential oral health care services. The prevalence of gingival inflammation is very high in all age groups in several African countries. The prevalence of maxillofacial trauma has increased in many countries, with a wide variation of the incidence and high prevalence of traumatic dental injuries in primary and permanent te...
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Research Interests:
SUMMARY Background Proximal contact tightness of class II resin composite restorations is influenced by a myriad of factors. Previous studies investigated the role of matrix band type and thickness, consistency of resin composite, and... more
SUMMARY Background Proximal contact tightness of class II resin composite restorations is influenced by a myriad of factors. Previous studies investigated the role of matrix band type and thickness, consistency of resin composite, and technique of placement. However, the effect of volumetric shrinkage of resin and intensity of curing light has yet to be determined. Thus, the aim of this study was to identify the influence of these factors on the proximal contact tightness when restoring class II cavity preparations in vitro. Methods Sixty artificial molars were restored with either a low-shrinkage (Filtek Silorane, 3M ESPE) or a conventional (Z100, 3M ESPE) composite and polymerized with low-intensity (Smartlite IQ2, Dentsply) or high-intensity light curing units (DemiTM, Kerr). Proximal contact tightness was measured using the Tooth Pressure Meter. Data were statistically analyzed using one-way analysis of variance and Tukey post hoc test. Results Use of low-shrinkage composite (Fi...
Research Interests: Materials Science, Dentistry, Dental Materials, Medicine, Polymerization, and 15 moreHumans, Operative Dentistry, Composite Material, Friction, Composite resins, Surface Properties, Shrinkage, Materials Testing, Silicon Dioxide, Resin Composite, Siloxanes, Molar, Dental marginal adaptation, Curing lights dental, and Silorane resins
The relative hardness (RH) of five composite materials was determined through polymerization via LED lights. Disk specimens were prepared by using composites composed of Artiste, an experimental glass fiber composite, Filtek Supreme,... more
The relative hardness (RH) of five composite materials was determined through polymerization via LED lights. Disk specimens were prepared by using composites composed of Artiste, an experimental glass fiber composite, Filtek Supreme, Z100, and LuxaCore. Specimens were polymerized for 10 and 20 seconds from the top surface only with two lights, Smartlite-IQ2 and DEMI LED, with light maintained 8 mm from the surface through a coronal section of the molar tooth. Knoop hardness numbers were determined for the top and bottom surfaces both immediately and 24 hours later. Ten RH values per group were calculated and data were statistically analyzed. Generally, RH increased with increasing polymerization time. The DEMI LED light resulted in RH values that were significantly higher than those obtained with Smartlite IQ2. Z100 had RH values of > 80% under most testing conditions and had the highest hardness values of all composites tested. Therefore, it is considered to be the most appropri...
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Purpose: This study determined shear bond strength (SBS) of two composite restoratives bonded to enamel and dentin immediately (after one day) and after one month of water-storage. Methods: Eighty intact molars were sterilized with Gamma... more
Purpose: This study determined shear bond strength (SBS) of two composite restoratives bonded to enamel and dentin immediately (after one day) and after one month of water-storage. Methods: Eighty intact molars were sterilized with Gamma irradiation and mounted in acrylic resin bases. These were divided into two equal groups. In one group buccal enamel was ground specimens 2mm thick and 3mm diameter prepared from two composites: Filtek-Z250 (Z250) (3M/ESPE, USA) and Filtek-LS (LS) (3M/ESPE, USA) were bonded to enamel and dentin surfaces. Single Bond (3M/ESPE, USA) adhesive was used with Z250 while LS adhesive (3M/ ESPE, USA) was used with LS. Each group was subdivided into 2 subgroups. One subgroup was Instron testing machine was used and force at failure was recorded. Mean and SDs were calculated and data statistically-analyzed using ANOVA. Results: For enamel, mean and SD for SBS in MPa measured immediately were: 18.4(1.9) and 9.4(1.3) for Z250 and LS, respectively. After one mont...
Purpose: This study investigated the effect of different bleaching methods on color change and surface roughness of human enamel. Materials M GP1: 3D Crest White Strips, GP2: Phillips Zoom Whitening Pen, GP3: Rembrandt Deeply White +... more
Purpose: This study investigated the effect of different bleaching methods on color change and surface roughness of human enamel. Materials M GP1: 3D Crest White Strips, GP2: Phillips Zoom Whitening Pen, GP3: Rembrandt Deeply White + Peroxide Mouthwash, GP4: Opalescence PF 15% CP, GP5: Opalescence Boost 40% HP (as control group). Bleaching was performed according to manufacturers’ instructions. Color change and enamel surface roughness measurements were performed by spectrophotometer and Atomic Force Microscope respectively at pre and post-bleaching intervals. Data were collected and statistically analyzed using ANOVA followed by Tukey’s HSD Post Hoc test (p≤0.05). Results: For color changes; mean ΔL* values were: 3.92(0.23), 2.44(0.15), 2.5(0.2), 2.6(0.17) and 4.1(0.25) for GP1, GP2, GP3, GP4, and GP5 respectively, Δa* means were: 0.6(0.04), 0.1(0.01), 0.15(0.01), 0.2(0.03) and 0.79(0.05) for GP1, GP2, GP3, GP4, and GP5 respectively, while means for Δb* were: 1.18(0.03), 0.33(0.01)...
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Research Interests:
Research Interests:
The relative hardness (RH) of five composite materials was determined through polymerization via LED lights. Disk specimens were prepared by using composites composed of Artiste, an experimental glass fiber composite, Filtek Supreme,... more
The relative hardness (RH) of five composite materials was determined through polymerization via LED lights. Disk specimens were prepared by using composites composed of Artiste, an experimental glass fiber composite, Filtek Supreme, Z100, and LuxaCore. Specimens were polymerized for 10 and 20 seconds from the top surface only with two lights, Smartlite-IQ2 and DEMI LED, with light maintained 8 mm from the surface through a coronal section of the molar tooth. Knoop hardness numbers were determined for the top and bottom surfaces both immediately and 24 hours later. Ten RH values per group were calculated and data were statistically analyzed. Generally, RH increased with increasing polymerization time. The DEMI LED light resulted in RH values that were significantly higher than those obtained with Smartlite IQ2. Z100 had RH values of > 80% under most testing conditions and had the highest hardness values of all composites tested. Therefore, it is considered to be the most appropri...
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Objective: This study determined the effect of caries detecting dyes on shear bond strength (SBS) of composite resin to dentine and examined the debonded surface topography. Method: Sixty intact recently extracted molars were sterilized... more
Objective: This study determined the effect of caries detecting dyes on shear bond strength (SBS) of composite resin to dentine and examined the debonded surface topography. Method: Sixty intact recently extracted molars were sterilized with Gamma radiation and mounted in acrylic resin bases. Teeth were divided into control group (20 molars) and experimental group (40 molars). They were further subdivided according to the type of caries detecting dye and the type of adhesive system used. The buccal surfaces of molars were grinded to remove enamel and expose flat surfaces of dentin. Two different caries detecting dyes were used Seek (Ultradent, USA) and SableSeek (Ultradent, USA), followed by application of either Excite (Ivoclar Vivadent, Liechtenstein) or AdheSE (Ivoclar Vivadent, Liechtenstein) according to the manufacturer's instructions. Cylinder specimens 2mm thick and 3mm diameter were prepared from Tetric Ceram composite (Ivoclar Vivadent, Liechtenstein) on each specimen....
Objective: This study investigated the effect of different matrix systems on proximal contact tightness of class II composite resin restorations. Method: 60 Ivorine teeth with standardized MO cavity preparations were randomly divided into... more
Objective: This study investigated the effect of different matrix systems on proximal contact tightness of class II composite resin restorations. Method: 60 Ivorine teeth with standardized MO cavity preparations were randomly divided into 4 equal groups according to the type of matrix systems used (n=15). Group1; sectional metal matrix (Standard matrix, Palodent, Dentsply), group2; pre-contoured circumferential metal matrix (KerrHawe 1101-c) in a Tofflemire retainer (Kerr Corporation), group3; conventional metal matrix (Hawe Tofflemire matrices, Kerr) in a Tofflemire retainer (Kerr Corporation), group4; Blue Cure-Thru transparent contoured matrix band (Premier Dental Products, USA). All matrices were combined with a separation ring (Composi-tight, Garrison Dental Solutions, USA). Matrices were secured with wooden wedges (Premier Dental Products, USA). Cavity preparations were restored with composite resin Z250 (3M/ESPE, USA) with the corresponding bonding system following manufactur...
Purpose: This in-vitro study evaluated surface polish of three resin composites qualitatively using different polishing procedures. Methods: 126 disc-shaped specimens (2mm-thick, 5mm-diameter) were prepared from three composites; Durafil... more
Purpose: This in-vitro study evaluated surface polish of three resin composites qualitatively using different polishing procedures. Methods: 126 disc-shaped specimens (2mm-thick, 5mm-diameter) were prepared from three composites; Durafil (Heraeus/Kulzer); FiltekSupreme-Plus (3M/ESPE); and Filtek-LS (3M/ESPE). Composites were packed into molds against Mylar-strip over glass section from one side (G0:control) and free-hand from the other side and light-cured for 40s using DEMI-LED (Kerr). Six specimens from each resin-composite were randomly assigned to one of six one-min polishing procedures (G1:PoGo tip; G2:Gloss-One disc; G3:Super-Snap medium, fine and extra fine discs; G4:PoGo tip/Prisma diamond polishing pastes (fine and extra fine); G5:Gloss-One/Prisma; G6:Super-Snap/Prisma). When Prisma was used polishing was for additional 40s. A seventh group where Super-Snap discs were used for three-min was also made (G7). One specimen from each group was assigned for SEM imaging while the ...
Purpose: This study determined shear bond strength (SBS) of two composite restoratives bonded to enamel and dentin immediately (after one day) and after one month of water-storage. Methods: Forty intact molars were sterilized with Gamma... more
Purpose: This study determined shear bond strength (SBS) of two composite restoratives bonded to enamel and dentin immediately (after one day) and after one month of water-storage. Methods: Forty intact molars were sterilized with Gamma irradiation and mounted in acrylic resin bases. These were divided into two equal groups. In one group buccal enamel was ground flat while in other buccal enamel was removed to expose flat dentin surface. Cylindrical specimens 2mm thick and 3mm diameter prepared from two composites: Filtek-Z250 (Z250) (3M/ESPE, USA) and Filtek-LS (LS) (3M/ESPE, USA) were bonded to enamel and dentin surfaces. Single Bond (3M/ESPE, USA) adhesive was used with Z250 while LS adhesive (3M/ESPE, USA) was used with LS. Each group was subdivided into 2 subgroups. One subgroup was tested after one-day storage in distilled water at 37C while other was tested after one-month. An Instron testing machine was used and force at failure was recorded. Means and SDs were calculated an...
Objectives: This study investigated the effect of polymerization shrinkage of low shrinkage composite, using two LED lights with different intensities, on proximal contact tightness of class II composite resin restorations. Methods: 40... more
Objectives: This study investigated the effect of polymerization shrinkage of low shrinkage composite, using two LED lights with different intensities, on proximal contact tightness of class II composite resin restorations. Methods: 40 Ivorine teeth with standardized MO cavity preparations were divided into 4 equal groups that were restored in a clinically relevant situation using KaVo manikin head. Groups were restored using: Filtek LS (LS) and Z100 (3M/ESPE, USA) with the corresponding bonding system following manufacturer's instructions. One group of each material was polymerized using Smartlite IQ2, Dentsply (IQ2) the other group was polymerized using DEMI-LED, Kerr (DEM) with light intensities of 700 and 1200 mW/cm2 respectively. All restorations were carried out using a standardized placement technique using a pre-contoured metal circumferential matrix (KerrHawe 1101-c) in conjunction with the V-ring separator (TrioDent, New Zealand). Composite material was applied increme...
The relative hardness (RH) of five composite materials was determined through polymerization via LED lights. Disk specimens were prepared by using composites composed of Artiste, an experimental glass fiber composite, Filtek Supreme,... more
The relative hardness (RH) of five composite materials was determined through polymerization via LED lights. Disk specimens were prepared by using composites composed of Artiste, an experimental glass fiber composite, Filtek Supreme, Z100, and LuxaCore. Specimens were polymerized for 10 and 20 seconds from the top surface only with two lights, Smartlite-IQ2 and DEMI LED, with light maintained 8 mm from the surface through a coronal section of the molar tooth. Knoop hardness numbers were determined for the top and bottom surfaces both immediately and 24 hours later. Ten RH values per group were calculated and data were statistically analyzed. Generally, RH increased with increasing polymerization time. The DEMI LED light resulted in RH values that were significantly higher than those obtained with Smartlite IQ2. Z100 had RH values of > 80% under most testing conditions and had the highest hardness values of all composites tested. Therefore, it is considered to be the most appropri...
Research Interests:
Objective: This study determined the effect of dentin surface angulations on shear bond strength (SBS) of composite resin to dentin and examined the debonded surface topography. Method: Eighty intact recently extracted human molars were... more
Objective: This study determined the effect of dentin surface angulations on shear bond strength (SBS) of composite resin to dentin and examined the debonded surface topography. Method: Eighty intact recently extracted human molars were sterilized with Gamma radiation and mounted in acrylic resin bases. The occlusal surfaces of molars were grinded to remove enamel and expose flat surfaces of dentin. Teeth were divided into two main groups (40 molars/each) according to the type of bonding systems used; Single Bond (3M/ESPE, USA) and Adper Scotchbond SE (3M/ESPE, USA). Each group was subdivided into 4 subgroups according to dentin surface angulations: D1; maxillary dentin surface was perpendicular to the floor, D2; maxillary dentin surface made a 45° to the floor, D3; maxillary dentin surface parallel to the floor and D4; mandibular dentin surface parallel to the floor. After application of adhesive systems according to manufacturer’s instructions, cylinder specimens 2mm thick and 3mm...
Research Interests:
This review aims to determine the prevalence and severity of oral health diseases in the Africa and Middle East region (AMER). The profile of oral diseases is not homogeneous across the AMER. There are large disparities between groups.... more
This review aims to determine the prevalence and severity of oral health diseases in the Africa and Middle East region (AMER). The
profile of oral diseases is not homogeneous across the AMER. There are large disparities between groups. Reliable data are scarce. The
prevalence and severity of oral diseases appear to be increasing in the African region, as does associated morbidity. There are substantial
differences in inequalities in oral health. Dental caries prevalence is less severe in most African countries than in developed countries,
but the high rate of untreated caries reflects the limited resources available and difficulties of access and affordability to essential oral
health care services. The prevalence of gingival inflammation is very high in all age groups in several African countries. The prevalence
of maxillofacial trauma has increased in many countries, with a wide variation of the incidence and high prevalence of traumatic dental
injuries in primary and permanent teeth. Orofacial clefts are among the most common birth defects. Annual incidence of oral cancer
is estimated as 25 cases per 100,000 people in Africa. Noma is a major public health problem for the Middle East and North African
(MENA) region. Data about human immunodeficiency virus/AIDS are limited, particularly in the MENA region. According to the World
Health Organization Regional Committee for Africa report, some fundamental key basic knowledge gaps need to be underlined. They
include inequalities in oral health, low priority for oral health, lack of adequate funding, inadequate dental student training, obstacles to
medical and dental research, and poor databases. There are very few effective public prevention and oral health promotion programs in
the AMER. Universal health coverage is not achievable without scientific research on the effectiveness of health promotion interventions
profile of oral diseases is not homogeneous across the AMER. There are large disparities between groups. Reliable data are scarce. The
prevalence and severity of oral diseases appear to be increasing in the African region, as does associated morbidity. There are substantial
differences in inequalities in oral health. Dental caries prevalence is less severe in most African countries than in developed countries,
but the high rate of untreated caries reflects the limited resources available and difficulties of access and affordability to essential oral
health care services. The prevalence of gingival inflammation is very high in all age groups in several African countries. The prevalence
of maxillofacial trauma has increased in many countries, with a wide variation of the incidence and high prevalence of traumatic dental
injuries in primary and permanent teeth. Orofacial clefts are among the most common birth defects. Annual incidence of oral cancer
is estimated as 25 cases per 100,000 people in Africa. Noma is a major public health problem for the Middle East and North African
(MENA) region. Data about human immunodeficiency virus/AIDS are limited, particularly in the MENA region. According to the World
Health Organization Regional Committee for Africa report, some fundamental key basic knowledge gaps need to be underlined. They
include inequalities in oral health, low priority for oral health, lack of adequate funding, inadequate dental student training, obstacles to
medical and dental research, and poor databases. There are very few effective public prevention and oral health promotion programs in
the AMER. Universal health coverage is not achievable without scientific research on the effectiveness of health promotion interventions