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Papers by sanaa hussein

Research paper thumbnail of Evaluation of Shear Bond Strength of High-Performance Polymers to Its Resin Veneering and to Dentin (In Vitro Study)

Alexandria Dental Journal

INTRODUCTION: : Looking through the wide range of prosthetic options High-performance polymers pr... more INTRODUCTION: : Looking through the wide range of prosthetic options High-performance polymers properties. Needs over layering resin veneer, bonded by a special adhesive, this adds an additional challenge to achieve adequate bond strength, also its bonding to tooth structure remains difficult. OBJECTIVES: To evaluate shear bond strength of CAD/CAM High-performance polymers (BioHPP) with its CAD/CAM veneering composite using two different adhesives, as well as to dentin using two types of cements. MATERIALS AND METHODS: This in vitro study, for Group I, twenty BioHPP discs with their CAD/CAM veneering composite, were milled and divided randomly into two subgroups (n =10) according to the adhesive system used. Subgroup IA: using DTK adhesive (dualhardening adhesive). Subgroup IB: using Combo.lign (dual-hardening adhesive). For Group II, twenty CAD/CAM High-performance polymers (BioHPP) discs were milled and divided into two subgroups according to the different cements used to lute to dentin surface. Subgroup IIA: using: RelyX Unicem resin cement, subgroup IIB: using Fuji Plus GI cement. After water storage, thermocycling (1200 cycles, 5°C/55°C) corresponding to one year of clinical service, all the specimens were subjected to shear force until failure and the results in the various groups were compared and statistically analyzed. Modes of failure were assessed. RESULTS: Mean SBS were as follows: subgroup IA (DTK adhesive 6.238), subgroup IB (combo.lign2.42), subgroup IIA (RelyX Unicem 2.07) and subgroup IIB (Fuji Plus 3.77). Mann-Whitney test demonstrated significant differences between the two subgroups in groups I and II (U= 2.0, P=.001) (U=17, P=.013) respectively. Stereomicroscope revealed that mixed and adhesive failure were the most dominant mode of failure. CONCLUSIONS MDP-Containing Self-adhesive Resin (DTK adhesive) is recommended as efficient adhesive to increase the shear bond strength of the veneering composite to BioHPP. Also Fuji Plus showed better bond strength than RelyX Unicem with BioHPP and dentin.

Research paper thumbnail of Evaluation of Shear Bond Strength of High-Performance Polymers to Its Resin Veneering and to Dentin (In Vitro Study)

Alexandria Dental Journal

Research paper thumbnail of Evaluation of Biaxial Flexural Strength and Translucency of Multichromatic Translucent Zirconia and Lithium Disilicate Ceramics

Alexandria Dental Journal, 2018

INTRODUCTION: Full-contour (monolithic) zirconia restorations are gaining in popularity. High tra... more INTRODUCTION: Full-contour (monolithic) zirconia restorations are gaining in popularity. High translucent zirconia materials and multilayered zirconia blocks might help to overcome the aesthetic drawbacks of traditional zirconia for fabrication of monolithic restorations OBJECTIVES: Were to evaluate the biaxial flexural strength and translucency of CAD/CAM: multichromatic ultra-translucent zirconia and comparing it with multichromatic high translucency Lithium Disilicate glass-ceramic. MATERIALS AND METHODS40 ceramic specimens were divided into two main groups; Group I: CAD/CAM multichromatic ultratranslucent Zirconia(UTML KATANA Zirconia) & Group II: Pressable multichromatic high translucent Lithium Disilicate glass-ceramic (e.max press multi). Each group was subdivided into two sub groups; sub group A: disc specimens (12mm diameter×1.5mm thickness) were fabricated (n=10) & thermocycled (500 cycles, 5°/55°C, 15 sec dwell time).Then, biaxial flexural strength was measured in MPa. Sub group B: rectangular specimens (12mm length × 10mm width × 1.5mm thickness) were fabricated (n=10). Spectrophotometric analysis was conducted to evaluate and compare the degree of translucency by translucency parameter (TP). Data were analyzed using student t-test & ANOVA with repeated measures test. RESULTS Statistical analysis of Biaxial flexural strength using student t-test revealed that group I (607.24 ± 71.79) showed higher statistically significant biaxial flexural strength values than group II (290.69 ± 41.19) (p <0.001*). Results of translucency revealed that there were significant statistical differences between the two subgroups where IPS e.max Press Multi provided better translucency than UTML KATANA zirconia. CONCLUSIONS: Multi layered zirconia showed higher mechanical, but lower optical properties than lithium disilicate. The multi layered zirconia showed four layers with different light transmittance capabilities. It might therefore be useful for enhancing the aesthetic appearance of full-contour zirconia restorations made from this material in stress bearing areas.

Research paper thumbnail of Evaluation of the adaptability and fracture strength of hi-ceram and duceram crown systems

International Journal of Chemical and Applied Biological Sciences, 2014

Research paper thumbnail of DNA methyltransferase 3B gene promotor and interleukin-1 receptor antagonist polymorphisms in Egyptian children with immune thrombocytopenic purpura

The Egyptian Journal of Haematology, 2016

Background and objectives Idiopathic thrombocytopenic purpura (ITP) is an autoimmune condition ch... more Background and objectives Idiopathic thrombocytopenic purpura (ITP) is an autoimmune condition characterized by increased platelet destruction. Although the etiology of ITP remains unclear, it is accepted that both environmental and genetic factors play an important role in the development of the disease. Many gene polymorphisms have been reported to be closely associated with the susceptibility to ITP. Aim of the work The current study aimed to investigate the association between the DNA methyltransferase DNMT3B-46359 C/T promoter and IL-1Ra polymorphism and the risk for acquisition of pediatric ITP in a cohort of Egyptian children. Patients and methods Genotyping of the studied genes using PCR-RFLP assays was conducted on 40 children with ITP and 20 age-matched and sex-matched normal controls. Results Our results revealed that DNMT3B-46359 C/T heterotype was higher in patients than in controls but did not reach statistical significance and conferred 2.2-fold increased risk for ITP (odds ratio=2.2, confidence interval = 1.4–2.6). There was no statistically significant difference between ITP patients and controls as regards allele frequency. Moreover, there was no statistically significant difference in the clinical and laboratory data between ITP patients with wild or mutant genotypes. Moreover, there was no statistically significant difference in the distribution of DNMT3B-46359 . C/T genotypes between acute and chronic ITP patients. Conclusion This genetic polymorphism cannot be considered as a molecular marker for ITP risk among Egyptian children. Moreover, it is not a molecular predictor for chronicity.

Research paper thumbnail of Evaluation of Shear Bond Strength of High-Performance Polymers to Its Resin Veneering and to Dentin (In Vitro Study)

Alexandria Dental Journal

INTRODUCTION: : Looking through the wide range of prosthetic options High-performance polymers pr... more INTRODUCTION: : Looking through the wide range of prosthetic options High-performance polymers properties. Needs over layering resin veneer, bonded by a special adhesive, this adds an additional challenge to achieve adequate bond strength, also its bonding to tooth structure remains difficult. OBJECTIVES: To evaluate shear bond strength of CAD/CAM High-performance polymers (BioHPP) with its CAD/CAM veneering composite using two different adhesives, as well as to dentin using two types of cements. MATERIALS AND METHODS: This in vitro study, for Group I, twenty BioHPP discs with their CAD/CAM veneering composite, were milled and divided randomly into two subgroups (n =10) according to the adhesive system used. Subgroup IA: using DTK adhesive (dualhardening adhesive). Subgroup IB: using Combo.lign (dual-hardening adhesive). For Group II, twenty CAD/CAM High-performance polymers (BioHPP) discs were milled and divided into two subgroups according to the different cements used to lute to dentin surface. Subgroup IIA: using: RelyX Unicem resin cement, subgroup IIB: using Fuji Plus GI cement. After water storage, thermocycling (1200 cycles, 5°C/55°C) corresponding to one year of clinical service, all the specimens were subjected to shear force until failure and the results in the various groups were compared and statistically analyzed. Modes of failure were assessed. RESULTS: Mean SBS were as follows: subgroup IA (DTK adhesive 6.238), subgroup IB (combo.lign2.42), subgroup IIA (RelyX Unicem 2.07) and subgroup IIB (Fuji Plus 3.77). Mann-Whitney test demonstrated significant differences between the two subgroups in groups I and II (U= 2.0, P=.001) (U=17, P=.013) respectively. Stereomicroscope revealed that mixed and adhesive failure were the most dominant mode of failure. CONCLUSIONS MDP-Containing Self-adhesive Resin (DTK adhesive) is recommended as efficient adhesive to increase the shear bond strength of the veneering composite to BioHPP. Also Fuji Plus showed better bond strength than RelyX Unicem with BioHPP and dentin.

Research paper thumbnail of Evaluation of Shear Bond Strength of High-Performance Polymers to Its Resin Veneering and to Dentin (In Vitro Study)

Alexandria Dental Journal

Research paper thumbnail of Evaluation of Biaxial Flexural Strength and Translucency of Multichromatic Translucent Zirconia and Lithium Disilicate Ceramics

Alexandria Dental Journal, 2018

INTRODUCTION: Full-contour (monolithic) zirconia restorations are gaining in popularity. High tra... more INTRODUCTION: Full-contour (monolithic) zirconia restorations are gaining in popularity. High translucent zirconia materials and multilayered zirconia blocks might help to overcome the aesthetic drawbacks of traditional zirconia for fabrication of monolithic restorations OBJECTIVES: Were to evaluate the biaxial flexural strength and translucency of CAD/CAM: multichromatic ultra-translucent zirconia and comparing it with multichromatic high translucency Lithium Disilicate glass-ceramic. MATERIALS AND METHODS40 ceramic specimens were divided into two main groups; Group I: CAD/CAM multichromatic ultratranslucent Zirconia(UTML KATANA Zirconia) & Group II: Pressable multichromatic high translucent Lithium Disilicate glass-ceramic (e.max press multi). Each group was subdivided into two sub groups; sub group A: disc specimens (12mm diameter×1.5mm thickness) were fabricated (n=10) & thermocycled (500 cycles, 5°/55°C, 15 sec dwell time).Then, biaxial flexural strength was measured in MPa. Sub group B: rectangular specimens (12mm length × 10mm width × 1.5mm thickness) were fabricated (n=10). Spectrophotometric analysis was conducted to evaluate and compare the degree of translucency by translucency parameter (TP). Data were analyzed using student t-test & ANOVA with repeated measures test. RESULTS Statistical analysis of Biaxial flexural strength using student t-test revealed that group I (607.24 ± 71.79) showed higher statistically significant biaxial flexural strength values than group II (290.69 ± 41.19) (p <0.001*). Results of translucency revealed that there were significant statistical differences between the two subgroups where IPS e.max Press Multi provided better translucency than UTML KATANA zirconia. CONCLUSIONS: Multi layered zirconia showed higher mechanical, but lower optical properties than lithium disilicate. The multi layered zirconia showed four layers with different light transmittance capabilities. It might therefore be useful for enhancing the aesthetic appearance of full-contour zirconia restorations made from this material in stress bearing areas.

Research paper thumbnail of Evaluation of the adaptability and fracture strength of hi-ceram and duceram crown systems

International Journal of Chemical and Applied Biological Sciences, 2014

Research paper thumbnail of DNA methyltransferase 3B gene promotor and interleukin-1 receptor antagonist polymorphisms in Egyptian children with immune thrombocytopenic purpura

The Egyptian Journal of Haematology, 2016

Background and objectives Idiopathic thrombocytopenic purpura (ITP) is an autoimmune condition ch... more Background and objectives Idiopathic thrombocytopenic purpura (ITP) is an autoimmune condition characterized by increased platelet destruction. Although the etiology of ITP remains unclear, it is accepted that both environmental and genetic factors play an important role in the development of the disease. Many gene polymorphisms have been reported to be closely associated with the susceptibility to ITP. Aim of the work The current study aimed to investigate the association between the DNA methyltransferase DNMT3B-46359 C/T promoter and IL-1Ra polymorphism and the risk for acquisition of pediatric ITP in a cohort of Egyptian children. Patients and methods Genotyping of the studied genes using PCR-RFLP assays was conducted on 40 children with ITP and 20 age-matched and sex-matched normal controls. Results Our results revealed that DNMT3B-46359 C/T heterotype was higher in patients than in controls but did not reach statistical significance and conferred 2.2-fold increased risk for ITP (odds ratio=2.2, confidence interval = 1.4–2.6). There was no statistically significant difference between ITP patients and controls as regards allele frequency. Moreover, there was no statistically significant difference in the clinical and laboratory data between ITP patients with wild or mutant genotypes. Moreover, there was no statistically significant difference in the distribution of DNMT3B-46359 . C/T genotypes between acute and chronic ITP patients. Conclusion This genetic polymorphism cannot be considered as a molecular marker for ITP risk among Egyptian children. Moreover, it is not a molecular predictor for chronicity.