Title: 1301 - Fatigue Resistance of 1mm Thickness CAD/CAM Crowns


Anthony Randi, columbia universtiy
mohammad abumelha (Presenter)
columbia universtiy


Objectives: To investigate the fatigue resistance of CAD/CAM lithium disilicate , monolithic Leucite-based glass-ceramics and zirconia reinforced lithium silicate of 1 mm full contour crowns adhesively luted to composite resin abutments.

Methods: Eighty standardized maxillary molar crowns were CAD/CAM milled using three different materials; monolithic lithium disilicate [IPS e.max®CAD], monolithic Leucite-based glass-ceramics [IPS Empress®CAD] and zirconia reinforced lithium silicate [CELTRA® DUO (ZLS) Polished and Crystallized]. Crowns were adhesively luted on CAD/CAM milled [Lava™ Ultimate] abutments using dual cure cement . All specimens were stored at 37oC for 24h. Crowns were loaded applying an eccentric force in a Willytec chewing simulator (steel stylus, cusp to fossa movment) with stepwise decrease of the load (21.3 , 19.3 , 17.3 , 15.3, 13.3 and 11.3 kg, 200,000 cycles each, 0.8 Hz). A two-way ANOVA and Tukey’s post hoc test will be used, at the level of 0.05 significance to test the fatigue resistance of the materials.

Results: The fatigue resistance measurements revealed that the monolithic lithium disilicate was superior to zirconia reinforced lithium silicate (fired). Lithium silicate unfired-polished revealed fatigue resistance similar to Leucite-based glass-ceramics respectively.

Conclusions: Monolithic CAD/CAM lithium disilicate demonstrate improved fracture fatigue compared to ZrLiSi (fired and polished) and leucite reinforced ceramics.

Student Presenter

Disclosure Statement:
The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: NONE

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