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Updated: Jan 8, 2026

Quasistatic Mechanical Testing for Computer-Aided Design and Manufacturing Occlusal Veneers Cemented to Milled Dentin Analog Material
Published on: December 20, 2024
Preparation designs and ceramic materials for premolar veneers: Effects on marginal adaptation and failure load
Cansu Akarsu1, Burcu Kanat-Ertürk2, Erhan Çõmlekoğlu3
1Department of Prosthodontics, Faculty of Dentistry, Kocaeli University, Kocaeli, Turkey, cansuyesildas.97@gmail.com.
Purpose:
To evaluate the effects of different preparation designs and ceramic materials on the marginal adaptation and failure load of laminate veneer restorations (LVRs) on premolars.
Methods:
Premolar LVRs (0.4 mm thickness) were fabricated using featheredge (F) and butt-joint (B) preparations and four ceramics; Cerec Tessera (CT), Vita Enamic (VE), IPS e.max CAD (EmC), and IPS e.max Press (EmP) (n= 80). Marginal gap (MG) was measured by silicone replica technique. After cementation on epoxy resin dies and 5,000 thermal-cycles, failure load (FL) was tested at the buccal cusp (0.5 mm/minute). Data were analyzed with a two-way ANOVA, Tukey, t-test, (P< 0.05), and fracture types were classified.
Results:
Preparation design and ceramic material had statistically significant effects on MG and FL (P< 0.001). B design showed significantly better MG and FL values than F design (P< 0.05). VE exhibited the lowest MG for both preparations, whereas EmP showed the highest MG for B, and EmP and CT for F (P< 0.05). CT showed significantly higher FL than EmP for both preparations (P< 0.05). All failures were catastrophic.
Clinical Significance:
The findings of this study provide clinical guidance for the selection of preparation design and ceramic material on premolar LVRs for smile design treatments. The results suggest that butt-joint preparation offers better mechanical strength and marginal adaptation, while CAD-CAM ceramics outperform pressed ceramics.

