paper - causes of early .. Flashcards
initial breakdown occurs?
reasonable loss?
begins at crestal region - even in succesfullly osseointegrated ones
first year = less than equal to .2mm - then annually thereafter?
saucerization
observed radiographically - after first year of function (prosthesis loading) - crestal bone loss to or beyond the first thread of titanium screw implants
top 6 reasons looke at for crestal loss
surgical trauma occlusal overload peri-implantitis presence of microgap formation of biologic width implant crest module
surgical trauma?
when implant surrounded by fibrous connective tissue or have apical extension of junctinal epi
temperature - overheated = risk of failure increased
periosteal elevation
- cancellous bone better than cortical
saucerization loss
if successful - not observed at stage 2
occlusal overload
bending overload = marginal bone loss / deossintegration
can have loss of crestal bone with overload - peri-implantitis can occur with severe overload and co-existance of inflammtion
cortical bone least resistant to
shear force - whic is increased by bending overload
stress reduction by
increasing surface area and decreasing forces
b/c stress is force divided by area
decrease microfracture by
axially directed occlusion as well as progressiveloading
implant failure in later stages?
peri-implantitis and overloading forces
flora associated with implantitis
similar to perio
bacteroides, fusobacteriu and spirochetes
site specific
history of perio in patient plays a role
faster destruction around implans because?
collagen fiber direction is parallel to implant surface vs perpendicular in tooth surfaces and more vascular structures around teeth
microgap in 1 stage?
this is non submerged — implant itsel exends above the alveolar crest level - therefor such a microgap does NOT exist at the level of the bone
microgap
between implant and abutment at or below the alveolar crest
countersinking places the microgap where
below crest of bone
Quirynen and van Steenberghe51 and Persson et
al.52 found microbial species cultivated from internal
surfaces of submerged implants or their restorative
component parts?
The study implied that a microbial leakage from the microgap between the
abutment/fixture interface in submerged implants is
the most probable origin for this contamination. However, the possibility of microbial contamination through
microgap between the abutment and fixture in submerged implants is related to development of periimplantitis, and its consequence is not limited to the
first year after loading.
crestal bone
levels appeared dependent on the location of the
the
microgap, approximately 2 mm below the microgap.
study by radiographically in dogs by Hermann et al.
and its importance / finding and meaning?
This study first demonstrated that the microgap between implant/abutment has a direct effect on
crestal bone loss independent of surgery approaches,
submerged or non-submerged
although microgap may not be considered as the only cause of early implant bone loss, it
might cause …?
implant crestal bone loss during the healing phase if it is placed AT OR BELOW THE BONY CREST
FORMATION of the bio width?
inevitably
occurs following biomechanisms regardless of implant
type
main contributing factors to early implant bone loss
reformation of biologic width,
occlusal overload, microgap and implant crest module are the most likely contributing causes for the
early implant bone loss phenomenon.
However, early
implant bone loss may also result from or depend on
surgical trauma, peri-implantitis, and others.
