Exam 1 Flashcards
Osseointegration definition
A direct functional and structural connection between living bone and the surface of a load carrying implant
Bone lost every time a flap is raised
about 0.7mm
Implant healing stages
2 hours after placement the wound chamber area (the deepest areas of the threads) fills with blood clot
At 4 days the wound chamber area is filling with fibroblasts
At 1 week woven bone osteoids are starting to form in the wound area.
At 2 weeks bone formation is developing
At 4 weeks the boney structures are starting to connect through to the base bone
at 12 weeks the wound chamber area is mostly remodeled
Contact osteogenesis
bone formation originating against the implant
Distant osteogenesis
Bone formation from the existing bone towards the implant
What healing stage are implants at their weakest point
4 weeks. Do not do anything to the implant at 4 weeks. Weaker than initial placement.
Biocompatibility
The ability of a material to perform with an appropriate host response in a specific application
Characteristics of mild implant failure
PD <4mm
Bleeding and purulent on gentle probing
Bone loss <25%
Characteristics of moderate implant failure
PD <6mm
Bleeding and purulent on gentle probing
bone loss 25-50%
Characteristics of Severe implant failure
PD >6mm
Bleeding and purulent on gentle probing
Bone loss >50%
Low surface energy
Tefflon - no water sticks to it. No cellular attachment will occur
High surface energy
Very hydrophylic. Will allow surface attachment of cells to this surface.
SLActive treatment
plasma treatment used to create superclean circuits. increases surface energy
Straumann loading time
SLActive claims to be able to load at 6 weeks rather than 8 weeks. Likely immediate loading is more successful as well
Downsides of rough implant surfaces
Bacteria can get in if recession occurs
rough edges break microscopically when implant is inserted. Tapping more important
type of attachment to implants
Hemidesmosomal
Common type of attachment around implants
long epithelial attachment as opposed to short epithelial attachment with inserted fibers into the tooth
Strength of epithelial attahcment around an implant
Much weaker, need to be much more careful probing around implants
Surface type epithelial cells like
Polished surface, horizontal grooves should be less than 10 microns in depth. laser Lock is deeper than this
Fibroblast movement
Move by themselves by grabbing a surface. Much better on a rough surface.
macrophages that cause healing around an implant
M2 - similar to the process of athersclerosos
M1 cause failure
Nobel implant surface
TiUnite
increases titanium oxide thickness
anodized surface
AstraTech surface
Fluoride modified surface
Stimumate osteoblast differentiation
improves osseointegration and decreases marginal bone loss in immediate loading protocols
Straumann implant surface
Acid etched
macrocraters overlayed with micropits
Risk factor definition
the probability of an individual developing a specific disease in a given period
Identified through longitudinal studies
Implant risk - Age
Does not seem to affect long term success rate
How to determine if a patient is done growing and can get their implant
lateral ceph 6 months apart. Still some debate if this means growth is fully stopped
Factors in considering success of an implant
bone levels cosmetic concerns complications with prosth BOP pt expectations
implant risk factors - smoking
considered the strongest modifiable risk factor
>10 cigarettes a day has more than 20% failure rate
20/day is the highest failure rate
smoking cessation 1 wk prior and 8 weeks after implant success rates similar
higher failure rate in maxilla than mandible in smokers
Smoking changes in bone
increases proinflammatory cytokines, inhibits fibroblasts, abnormal PMN phagocytosis, altered lymphocyte, decreases vascularity, delayd
Implant risk factor - diabetes
Poorly controlled diabetes (HbA1c >7%) negatively affects osseointegration
well controlled has no effect
Antiseptic mouth rinses and OH maintenance helps in achieving successful osseointegration
Diabetes effects on bone
impairs growth and regeneration of blood vessels, impair collagen metabolism, impaired bone metabolism, and advanced glycation end products
Risk factors for implants - osteoporosis
unclear relationship with periodontitis
No convincing data for osseointegration
T score less than -2.5
Implant risk factors - bisphosphonates
Higher risk of MRONJ with implant or any surgical procedure. Separate informed consent form. IV much higher risk than oral
Risk factor for implants - previous periodontal disease
substantial increase in peri-implantitis. 3X higher
14X higher risk of peri-implant mucocitis
implant risk factor - grafted vs host bone
A little ambiguous but seems to be similar survival rates
Implant risk factor - bone quality
Class 1-3 same survival, class 4 lower with rough implant surfaces
Implant risk factors - Keratinized tissue
<2mm peri-implant mucosa should increased GI, PIU, bone loss, and BOP
Some studies showed no difference
Socket preservation phases of healing
Inflammatory - Coagulation day 1, inflammatory cell and granulation tissue day 2-3
Proliferative - fibrogenesis/provisional matrix day 7, woven bone formation day 14, bone modeling day 30, bone remodeling day 90
Alveolar socket healing
clot breakdown 48-72 hours as granulation tissue infiltrates. Epithelium at socket periphery start at 3-4 days.
Complete infiltration of granulation tissue and replacement of a clot in 7 days
If you have 0.5mm facial bone post extraction
You will lose all the facial plate during healing. Socket preservation is much more important in these cases
If you have less than 2mm socket graft, if you have more you can get away without it
Socket preserve any endo treatment, especially apico
Soft tissue formation in augmented healing
You get more soft tissue thickness naturally than in augmented healing. Can do extraction, wait 4-5 weeks, then do bone augmentation
Osteoinduction
the process of stimulating osteogenesis (demineralized exposes the cells to try to get more osteoinduction)
Osteoconduction
actinv as a scaffold for bone to build off of, keeping soft tissue out
Autograft as a bone material
Osteoconductive, but resorbs very quickly
Demineralized allograft
better for osteoinduction, have lost most of their structure, better for small sockets
Freeze dried allograft
better for osteoconduction, better for larger sockets as it lasts longer
Xenograft as a bone material
osteoconductive scaffold, very slow resorption, still there even 10 years out
Alloplasts as a bone material
lab fabricated, biologically inert osteoconductive
Socket seal procedure
in a 4 wall defect, use a soft tissue graft over the socket to seal it