CHIPPING PROBLEM :(
Please check the following which could have caused the problem:
• Please measure the Wax Pattern when you doing the Wax Modulation, It should be 0.3mm after Finishing of Metal.
• Never mix alloys.
• You must Take care of Sharp Edges in Metal Framework, Always prefer U shape Modellation of Interdental Space.
• Do not use more than one third of old metal.
• Always Prefer Indirect Spruing Technique
• Metal Framework should be Homogeneous.
• Always prefer to Use Clean Sandblasting Material and prefer to Use 50- 250 Micron Aluminium Oxide depending on the Alloy (Observe Manufacturer’s Instruction).
• Always prefer Cross-Cut tungsten Carbide Burs for Finishing of Metal in One Direction
• Do not Use Diamond Abrasive or Diamond Coated Burs for Finishing of Metal.
• Finish Metal Properly, Remove all the Investment Particles from the Metal Framework.
• Please refer the Correct Firing Parameter (Manufacturers Firing Table)
VITA VMK Master Firing Programme.
• Grind the surface of the ceramic with diamond abrasives.Make sure the ceramic does not get too hot.
• Please Avoid Direct heat when you are baking the Ceramic. Always prefer Lift Position in dryingprocess when you are firing the Ceramic.
Author - KAPIL CHHABRA - (VITA-ZAHNFABRIK)