Purpose: Assess the effect of material selection as well as different fabrication techniques of metal ceramic (MC) and all ceramic crowns on their clinical outcomes, marginal and internal fit. Materials and methods: In vivo study(I); twenty-eight patients were provided with twenty-eight crowns restoring mandibular first molar tooth.Patients were distributed into 2 groups and 2 subgroups according to different materials and fabrication techniques: fourteen patients received MC crowns, group (I); seven patients received crowns with conventional casting of Co-Cr copings, subgroup (A) and seven patients received crowns with direct milling of Co-Cr copings, subgroup (B). Fourteen patients received IPS e.max press crowns, group (II); seven patients received crowns with conventional wax pattern, subgroup (A) and seven patients received crowns with 3D printing resin pattern, subgroup (B). The survival rate of these crowns was evaluated and statistically analyzed. In vitro study(II); one machined die was prepared to simulate crown preparation of mandibular first molar tooth. 60 crowns were constructed on die and divided into 2 groups (30 samples each) and 2 subgroups (15 samples each) according to different materials and fabrication techniques similar to in vivo study. Replica technique obtained to measure marginal and internal fit using Digital microscope. Results: The survival rate of MC and press crowns was 98% and 60% respectively. Press crowns and digital technique showed superior marginal and internal fit than MC crowns and conventional technique respectively. Conclusions: Material type and fabrication technique of MC and all ceramic crownsinfluence their clinical outcome, marginal and internal fit.

Purpose: This study evaluated the influence of different ceramics and resin cements on marginal discrepancy, color stability and fracture resistance of ceramic veneers. Material and methods: Sixty sound human maxillary first premolars were prepared for ceramic veneers. Prepared teeth were randomly divided into 3 equal groups according to materials used for construction of laminate veneers. Twenty ceramic veneers were fabricated from Vita Suprinity blocks, other twenty from Vita Enamic blocks and the last from IPS Emprees CAD blocks. Each main group were randomly subdivided equally into two sub groups according to adhesive system used. All samples were subjected to thermo cycling. Marginal discrepancy was measured by stereomicroscope before, after cementation and after thermo cycling and color was measured by digital spectrophotometer before, after cementation then all samples were subjected to fracture. Results: Marginal discrepancy in both Vita Suprinity, Empress CAD and Vita Enamic ceramic veneers were less than 100 µ within acceptable value. The highest color changes recorded with V. Enamic followed by Emp CAD while the lowest color changes recorded with V. Suprinity and this was statistically significant. The highest fracture resistance recorded with V. Suprinity followed by Emp CAD while the lowest fracture resistance recorded with V. Enamic and this was statistically significant. Conclusions: Ceramic veneers fabricated by Vita Suprinity, Empress CAD and Vita Enamic provided clinically acceptable marginal fit. Vita Suprinity veneers provide more color stability and highest fracture resistance than Empress CAD and Vita Enamic.

Massive intraventricular hemorrhage (IVH) in neonates is followed by progressive ventricular dilatation in 55?80% of cases if the infant survives. The initial mechanism of posthemorrhagic hydrocephalus (PHH) is thought to be obstruction by multiple small blood clots of the channels of the cerebrospinal fluid (CSF) to areas of absorption. Plasminogen activator inhibitor-1 (PAI-1) is the principal regulator of fibrinolysis in blood and one of the most highly controlled of the fibrinolytic components. The aim of this study is to measure plasminogen and PAI-1 levels in plasma and CSF of the neonates after IVH to assess endogenous fibrinolytic activity and to predict the development of PHH. Fifteen full term and preterm neonates with IVH were enrolled in the study. Ten neonates without IVH were used as a control group. Cranial ultrasound was performed at age of 2 weeks and 2 months. Plasma and CSF plasminogen and PAI-1 levels were assessed for these neonates. CSF PAI-1 was significantly higher in infants with IVH than in the controls (P < 0.001). There was no significant difference in the CSF and plasma plasminogen between infants with IVH and controls (P > 0.05). CSF PAI-1 was significantly higher in infants with PHH than in infants with posthemorrhagic ventricular dilatation (P < 0.05), with a sensitivity (100%) and specificity (100%). CSF PAI-1 is a very sensitive and specific parameter than CSF plasminogen for prediction of PHH in neonates with IVH, and this might be useful to evaluate the specific therapeutic programs of these neonates.

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