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CAMLOG&Science – Chapter 3
ZrO
2
ABUTMENTS – WEAR AND RECOMMENDATIONS FOR USE
Wear is an important aspect regarding the long-term success of implant-
abutment connections. Stimmelmayr et al. (2012a) evaluated the wear of
the interface between CAMLOG
®
titanium implants and one-piece zirconia
abutments and compared it to titanium abutments in an in vitro study. Che-
wing simulation was performed with a similar test set-up as designed by
Steinebrunner et al. (2005; Fig. 10A). After loading with 1.200.000 cycles
at 100N, neither implant or abutment fractures nor abutment screw loose-
ning or screw fractures occurred. However, SEMmicrographs revealed more
wear and damage at the implants when they were connected to ZrO
2
abut-
ments. The authors supposed that the reason for these differences was the
stress distribution between components of different rigidity: When using
ZrO
2
abutments on titanium implants, deformation energy is distributed to
the material with the lower elastic properties, i.e., titanium, which results
in increased wear and abrasion.
Use and processing of ZrO
2
abutments were also discussed at a consensus
conference and the following recommendations were developed (Beuer et al.,
2011):
• ZrO
2
qualities differ in their mechanical and optical properties. Only tho-
roughly tested, well known and scientifically documented ZrO
2
qualities
should be used.
• One-piece monoblock ZrO
2
abutments with inner connections should not
be used in the lateral tooth area. In the front area, one-piece abutments
with outer connections and appropriate dimensions show fewer problems.
• Two-piece, bonded ZrO
2
abutments, do not show any limitations in use
as long as they have appropriate dimensions.
• On standardized ready-for-use ZrO
2
abutments, crowns should be fixed
in a conventional way since surplus fixation material is difficult to remove
if the crown margin is placed subgingivally.
• When using individually CAD/CAM-prepared ZrO
2
abutments with which
themargin can be placed to bewell accessible, also adhesive / semi-adhesive
systems may be used.
• In restorations which are fixed only by adhesion and without additional
retentive preparations, classical adhesive multiple step systems should be
used.
• It is strongly recommended not to fix ZrO
2
restorations provisionally.