Lithium disilicate as a dental restorative material
Introduction/Context/Diagnosis
Glass ceramics are superior in aesthetics and biocompatibility. Traditional glass ceramics, such as feldspar and leucite glass ceramics, have been used for several decades as veneers, inlays, onlays and single crowns. Due to their strength limitations, they had high failure rates for load-bearing restorations. lithium disilicate glass ceramics (LDGC) have been developed for both pressing and CAD/CAM processes.
COMPOSITION: They are derived from the SiO2–Li2O–Al2O3–K2O–ZrO2–P2O5 system through formation and solid state reaction LDGC consist of approximately 70% needle-like lithium disilicate(Li2Si2O5) crystals embedded in a glassy matrix containing disilicate and other oxides. There enforced lithium disilicate crystals have sizes of 3–6 μm in length and 0.5–0.8 μm in width, with interlocked and layered microstructures to strengthen LDGC.
Methods/Treatment Plan
INDICATIONS/CONTRADICTIONS: A variety of aesthetic restorations for f/p coverage. We can use for both simple and multiple abutment units. Bridges should be limited to anterior teeth to second premolar. More recently being used as hybrid abutments with implant restorations. We are also seeing fusion with zirconia, with the aim of being the ultimate restorative material. Posterior bridges reaching into the molar region, 4- and more-unit bridges, Inlay-retained bridges, Very deep subgingival preparations, patients with severely reduced residual dentition, Bruxism, Cantilever bridges, Maryland bridges, Failure to observe the necessary minimum connector dimensions and layer thicknesses and Any other use not listed in the indications.
Results/Outcome
ITS USE IN CLINIC: Given the processing in its blue intermediate phase by means of the CAD/CAM technology and a subsequent short crystallization procedure, the LDS- CAD lithium disilicate (LS2) glass-ceramic is the innovative all-ceramic material for all CAD/CAM- fabricated single-tooth restorations. The technique is the latest development in the field of digital restorations. It combines the advantage of IPS e.max LS2 and ZrO2 in an innovative fashion and thus introduces a new generation of restorations in the bridge technique, which inspires users with regard to the combination of user friendliness, speed and overall strength.
Significance/Conclusions
The abrasion of glass-ceramic crowns is so low that the aesthetic and biological advantages over metal and metal-ceramic restorations prevail. LDS CAD crowns showed good values comparable to those of the gold standard, i.e. metal-ceramics. Crowns made of LDS- CAD proved their clinical efficiency over a period of 3 years; no fractures or chipping occurred.
Location
University of the Pacific, Dugoni Dental School, San Francisco, CA
Format
Poster
Poster Session
IDS Student Presentations
Lithium disilicate as a dental restorative material
University of the Pacific, Dugoni Dental School, San Francisco, CA
Glass ceramics are superior in aesthetics and biocompatibility. Traditional glass ceramics, such as feldspar and leucite glass ceramics, have been used for several decades as veneers, inlays, onlays and single crowns. Due to their strength limitations, they had high failure rates for load-bearing restorations. lithium disilicate glass ceramics (LDGC) have been developed for both pressing and CAD/CAM processes.
COMPOSITION: They are derived from the SiO2–Li2O–Al2O3–K2O–ZrO2–P2O5 system through formation and solid state reaction LDGC consist of approximately 70% needle-like lithium disilicate(Li2Si2O5) crystals embedded in a glassy matrix containing disilicate and other oxides. There enforced lithium disilicate crystals have sizes of 3–6 μm in length and 0.5–0.8 μm in width, with interlocked and layered microstructures to strengthen LDGC.
