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.

Background Vaccination of masses against coronavirus disease 2019 (COVID-19) is critical to overcome the pandemic and restore normalcy. However, vaccine refusal and hesitancy prevail in many countries. COVID-19 has rapidly spread in Saudi Arabia since 2020. The acceptance rate of COVID-19 vaccines has been investigated in adults aged >18 years in Saudi Arabia. This study aimed to understand the acceptance and hesitancy of parents to vaccinate children aged <12 years against COVID-19 in Saudi Arabia and identify strategies that can encourage their engagement. Methods We used an online cross-sectional survey distributed to parents who lived in all regions of Saudi Arabia to investigate parents’ views on the acceptability of a future COVID-19 vaccine for their children aged <12 years. Five hundred parents living in Saudi Arabia completed the survey. Results The survey indicated that mothers were more enthusiastic about participating in the study than fathers. The participant aged 37.31 ± 8.52 years. A total of 38.6% of participants refused to vaccinate their children. Additionally, 56% were unsure if the vaccine would cause serious side effects in children. A total of 48.8% of parents believed that the Pfizer vaccine was suitable for children, while 64.5% failed to decide whether to administer vaccines to their children. Conclusion Vaccine hesitancy remains a major problem worldwide. A lack of scientific evidence on vaccine efficacy, low education level, and reduced level of health education and promotion are the most common factors in parents in Saudi Arabia. However, some participants agreed to receive vaccines only to protect their family members, and due to governmental rules and school mandates. Therefore, vaccine efficacy and safety in children must be clearly communicated to the public. This information would aid in reducing the hesitancy of parents to vaccinate their children against COVID-19.

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.

Introduction: Porcelain laminate veneers are sometimes necessary after bleaching in patients requiring marked change in tooth color. Bonding following bleaching has been shown to be compromised. The use of an antioxidant agent and delayed bonding could improve bonding. Aim of the study: was to evaluate the effect of antioxidant treatment and delayed bonding, one week after bleaching, on the shear bond strength of porcelain laminate veneers bonded to bleached enamel in comparison with immediate bonding after bleaching. Materials and methods: Forty freshly extracted maxillary central incisors with flat enamel surfaces were prepared and divided into four groups (n=10/group). Three test groups were bleached with 40% hydrogen peroxide (Power Whitening) and one control group was left as unbleached enamel. Forty glass ceramic discs were fabricated using IPS e.max Press to be bonded to the enamel surface. Group A:antioxidant treated specimens. Bleached specimens were treated with an antioxidant agent, 10% sodium ascorbate, for 10 minutes then glass ceramic discs were bonded to the specimens. Group B:delayed bonded specimens. Bleached specimens were stored in artificial saliva for 7 days then glass ceramic discs were bonded to the specimens. Group C: immediate bonded specimens. Glass ceramic discs were immediately bonded to bleached specimens. Group D:control group. Glass ceramic discs were bonded to unbleached specimens. Dual cured resin cement (RelyX U200) was used for bonding. Following bonding, the specimens were thermocycled for 600 cycles corresponding to one clinical year service then tested for shear bond strength using a universal testing machine at a crosshead speed of 0.5 mm/min. Bond failure analysis was evaluated for the specimens using a stereomicroscope and random samples were chosen to be tested under a scanning electron microscope. Results: No significant difference was found between the control, delayed bonding and antioxidant treated group (p<0.001). Immediately bonded group showed significantly lower mean bond strength with glass ceramic discs than all groups (p<0.001). Conclusions: It is recommended to delay bonding for one week after bleaching or use 10% sodium ascorbate to reverse bleaching.

his study was carried out to evaluate beefburger prepared by 2% lemongrass, 2% thyme, 1% from lemongrass plus thyme and 0.5% from lemongrass and thyme addition in relative to control beefburger without addition. (moisture, protein, fat, ash and total carbohydrates) were determined in raw materials (lemongrass and thyme), beefburger and their formulas during storage period. Thiobarbituric acid, the total volatile nitrogen, pH values, water holding capacity, plasticity cooking loss, cooking yield, shrinkage and total bacterial count were determined in beefburger and their formulas during storage period for 3 months at-18 o C. Moreover organoleptic characteristics were determined in fresh beefburger and their formulas. The results showed that the moisture and protein were decreased by increasing storage period as well as total lipids, ash, crude fibers and total carbohydrates were increased. Storage deteriorated both plasticity and WHC. Shrinkage and cooking loss increased by storage. For the supplemented samples, the best formula was recorded in case of the lemongrass/thyme mixture, specially at the lower ratio (0.5). The best supplemented sample were recorded in the lemongrass group. Cooking yield decreased by storage and the best supplemented sample was that of the individual lemongrass group. As the storage period increased, the total volatile nitrogen (TVN) and thiobarbituric acid (TBA) values increased for all beefburger and their formulas, samples. During the storage period, the control beefburger showed the highest of total bacterial count. While, their formulas reported that the lowest in total bacterial count were in 2% lemongrass formula, followed by (1%+1%) lemongrass and thyme formula and then 2% thyme formula. The organoleptic evaluations showed that the formula contained 2% lemongrass gave the best acceptability (36.0) followed by the formula contained equal weight (1%) of both lemongrass and thyme (32.0). Moreover, the formula prepared from 2% thyme have a medium acceptability (30.0) as well as the formula contained equal weight (0.5%) of both lemongrass and thyme which showed the lowest overall acceptability. It can be recommended that the lemongrass and thyme can play an important role as antioxidant and antibacterial agents in refrigerated beefburger and their formulas, but lemongrass is the best one. T