Background: This study was conducted to compare the linear dimensional accuracy of die materials before and after disinfection of the impression. Type IV and V conventional dental stone, type IV-resin impregnated and copper-plated die materials were studied.

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Cranial defects lead to unesthetic appearance and are a constant source of apprehension to the patient. Meningioma with calvarial extension requires the excision of the involved bone for complete excision. Such total excision would leave behind a bony defect which would need reconstruction. Presurgical fabrication of acrylic flap helps in reconstruction of such cranial defect following complete excision in single stage, thereby decreasing the cost and morbidity of surgery. Further, it facilitates the reproduction of the contours, and the tissue bed is not exposed to the heat of polymerization or to the free monomer. The authors report a case of hyperostotic convexity meningioma in a middle-aged female where heat-cured acrylic resin alloplastic implant was prefabricated and used successfully.

Aim:To establish an effective combination of drying time and drying method of the tray adhesive so that maximum bond strength can be achieved between impression tray and impression material.Materials and methods: Cylindrical specimens of autopolymerizing resin and addition silicone impression material were made. A total of 150 specimens were tested. They were divided into two groups Dentsply and GC. Each group was further divided into five subgroups:• Drying with compressed air for half the time as recommended by the manufacturer • Drying with air blower for half the time as recommended by the manufacturer • Open air drying as recommended by the manufacturer • Open air drying for 15 minutes • Open air drying for 1 hour The samples were tested for tensile bond strength using the universal testing machine. The results were subjected to statistical analysis.Result: Open air drying as recommended by the manufacturer was better than drying with a blower or compressed air. There was no significant difference between open-air drying for 5 minutes and open-air drying for 15 minutes or 1 hour. Conclusion:Open air drying as recommended by the manufacturer, i.e. 5min, showed good bond strength and drying for more than 5mins does not significantly increase bond strength.Clinical significance: Tray adhesive should not be dried with compressed air or air blower. Tray adhesive should be applied and kept to dry according to the manufacturer's recommended time.

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