1.
J Prosthet Dent
; 57(1): 47-52, 1987 Jan.
Article
in English
| MEDLINE
| ID: mdl-3468249
ABSTRACT
To clarify the nature and longevity of the extrinsic stain layer of metal-ceramic restorations, a series of experiments were undertaken. It was found, with microscopic examination, that there is little or no diffusion of the stain into the underlying porcelain and that at a thickness of 22 microns the extrinsic stain layer is grossly evident to an observer. Using a fluoride dentifrice caused no significant loss of either stain or surface integrity with 120,000 brush strokes (equivalent to 8.5 years). At 160,000 strokes (equivalent to 11.4 years) there was evidence of loss of surface integrity.