The effect on cast post dimensions of casting investment and airborne particle abrasion.
Cast posts can sometimes prove difficult to seat fully during fitting. This study compared two different liquid/water dilutions for phosphate bonded investment and the effect of controlled airborne particle abrasion on resulting post diameter. After measuring polymeric post patterns (n = 18), 3 groups were invested using concentrated solution and 3 groups using dilute solution. After casting they were weighed and remeasured then exposed to airborne particle abrasion. Both solutions produced oversized cast posts. Mean diameter reduction during airborne particle abrasion was 8 microm/10s taking an average of 41s to reach precast size. Where a post pattern fits tightly, airborne particle abrasion for 70s should reduce the casting sufficiently to accommodate the cement lute.
Department of Restorative Dentistry, School of Dental Science, Newcastle University, Newcastle Upon Tyne, UK.
Danya
D
Hashem
Matthew J
MJ
German
Robert W
RW
Wassell
D000537:Aluminum Oxide / Q000737:chemistry; D003102:Colloids / Q000737:chemistry; D003734:Dental Casting Investment / Q000737:chemistry*; D003735:Dental Casting Technique; D045662:Dental Etching / Q000379:methods*; D018772:Dental Marginal Adaptation; D017267:Dental Prosthesis Design; D006047:Gold Alloys / Q000737:chemistry; D006358:Hot Temperature; D006801:Humans; D006851:Hydrochloric Acid / Q000737:chemistry; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D010710:Phosphates / Q000737:chemistry; D011176:Post and Core Technique / Q000295:instrumentation*; D012822:Silicon Dioxide / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D014867:Water / Q000737:chemistry
D003102:Colloids; D003734:Dental Casting Investment; D006047:Gold Alloys; D010710:Phosphates; D012996:Solutions; D014867:Water; D012822:Silicon Dioxide; D000537:Aluminum Oxide; D006851:Hydrochloric Acid