VITA Easyshade® Advance – Irren war menschlich!

Schlussfolgerung: Die beiden neuen Prothesenbasismaterialien zeigten ähnliche Ergeb -
nisse wie die anderen Injektionssysteme. Das Gießverfahren wies mit Abstand die
schlechteste Oberflächenqualität auf.
Hinweis: Diese Studie wurde zum Teil von der Firma Ivoclar Vivadent AG unterstützt.
P10
In vitro evaluation of bonding strength of veneering ceramics to zirconia copings
Yu-sung Choi a *, Sung-hun Kim b *
a Department of Prosthodontics, College of Dentistry, Dankook University, Cheonan,
Republic of Korea
b Department of Prosthodontics and Dental Research Institute, School of Dentistry,
Seoul National University, 275-1, Yeongeon-dong, Jongno-gu, Seoul, Republic of
Korea
Objectives: With this in vitro study the bonding strength of zirconia-based crown copings
being veneered with a CAD/CAM generated high-strength ceramic cap by sintering
is compared with anatomically identical zirconia-based crowns, which were either
heat-pressed or veneered by the layering technique for completion.
Materials and Methods: A 1.2mm, 360◦ chamfer preparation was performed on a first
mandibular molar and 36 model dies was fabricated in a titanium alloy. A sample of
36 zirconia copings was produced and divided into three groups. In the first group (LT)
zirconia copings received conventional veneering in layering technique, in the second
group the veneering porcelain was heat-pressed the zirconia coping (HT), and for the
third group (ST) a CAD/CAM-fabricated high-strength anatomically shaped veneering
cap was sintered onto the zirconia coping. All crowns were cemented conventionally
onto their dies and tested in the universal testing machine until clinical failure. The fracture
load data were compared by a one-way analysis of variance and a multiple comparison
posthoc test(< 0.05). Scanning electron microscope pictures have used to
show a sound bond between the connector material, internal framework material and
external veneer cap.
Results: Specimens from group LT showed a mean (S.D.) fracture load of 1860.39
(1238.72) N, group HT 5277.73 (1181.11) N and group ST 4284.67 (2257.42) N. The
difference between groups LT and HT/ST were statistically significant (P < 0.001).
Conclusion: The new CAD/CAM-fabricated bilayered restorations (ST) and heat-pressed
techniques (HT) were superior to the conventional layering techniques (LT) in terms of
fracture load and offer the possibility to produce cost-effective crowns and fixed partial
dentures with a potential lower risk of chippings.
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