Alteration of the intaglio surface of lithium disilicate glass-ceramic

Catherine M. Gorman, Daithi de Faoite, David Flannery, Marta Ratajczak, Tomás Kelly, Kenneth T. Stanton

Research output: Contribution to journalArticlepeer-review

Abstract

Statement of problem: Clinical adjustment of a lithium disilicate glass-ceramic (LDGC) restoration may necessitate its return to the laboratory for additional firing. Evidence of how the intaglio surface should be re-etched after internal adjustment, or after refiring, is lacking. Purpose: The purpose of this in vitro study was to investigate the effects of different sequences of etching, refiring, diamond rotary instrument adjustment, airborne-particle abrasion, and re-etching on the microstructure and surface roughness of the intaglio surface of heat-pressed LDGCs. Material and methods: Heat-pressed LDGC specimens were ground with abrasive paper to produce a uniformly flat surface. The groups (n=3) were subjected to different combinations of etching, refiring, diamond rotary instrument adjustment, airborne-particle abrasion, and re-etching. X-ray diffraction was used to characterize the crystalline phases. Scanning electron microscopy and surface profilometry were used to characterize the microstructure and surface roughness. Results: Qualitative differences were observed in the surface texture of specimens etched for different periods. Excessive etching revealed more of the underlying lithium disilicate crystallites and caused surface pitting for the longest etching period studied. Refiring altered the surface condition but did not completely remove the texture created by the original etching. Diamond rotary instrument adjustment resulted in appreciable surface damage and a higher mean value of measured surface roughness (with or without re-etching) than the other groups. Airborne-particle abrasion caused embedding of particles in the specimen surface, likely corresponding to the abrasion media, although this process resulted in qualitatively less surface damage than diamond rotary instrument adjustment. Conclusions: Excessive etching, refiring, and adjustment by airborne-particle abrasion or diamond rotary instrument result in qualitative changes in surface condition. Adjustment by diamond rotary instrument results in appreciable surface damage.

Original languageEnglish
Pages (from-to)411.e1-411.e10
JournalJournal of Prosthetic Dentistry
Volume122
Issue number4
DOIs
Publication statusPublished - Oct 2019
Externally publishedYes

Fingerprint

Dive into the research topics of 'Alteration of the intaglio surface of lithium disilicate glass-ceramic'. Together they form a unique fingerprint.

Cite this