DENTAL IMPLANTS Flashcards
Define osseointegration
Direct structural and functional connection between ordered, living bone and the surface of a load carrying implant at the microscopic level.
**oxide layer makes it corrosion resistant and biocompatible.
Albrektsson criteria for success
- absence of mobility
- absence of pain, parasthesia, violation of vital structures
- absence of peri implant radiolucency
- absence of significant marginal bone loss after the first year of function.
Long term success and survival
Mandible>maxilla
Survival and success of osseointegrated implants from longitudinal studies Systematic Review 2015
Success 89.7%
Survival 94.6%
*70% of failures occur after abutment placement and loading.
Factors that may affect implant success/survival
Bone quantity and quality
Surgical technique
Implant macrogeometry
Implant surface characteristics
implant length and width
smoking
plaque
residual cement
occlusion
lack of KT
Jaw location
Medical conditions and medications
Which macrofeature of implants is associated with better stress distribution
microthreads
Rough vs machine surfaces?
All rough surfaces are superior to machined surfaces for bone to implant contact
What are some common implant surface topographies?
Nanotite(Zimmer)- crystalline deposition of Calcium Phosphate
Osseospeed (Astra)- fluoride modification of TiOblast surface which improves affinity to react with phosphates making the surface attractive to CaP
SLActive- storing dental implants in isotonic NaCl solution
Laser Lok- cell sized microchannels- laser ablation
Any evidence on a particular implant having superior long term success over others?
no
Length of implant and success/survival
several studies suggest short implants are equally successful.
Considerations when using short implants
- increase width —>increase SA
- Use 2 stage approach
- Avoid as single implants in free end
- need > or = to 2 splinted
- Care with occlusion; bruxism
- Consider opposing dentition
Does width of implant matter
Small diameters are equally as successful.
Narrow diameter have similar 1-3 year survival rates as regular diameter
Some studies indicate that wider implants are better however, smaller diameters work well in many situations
- consider biomechanical risks
- consider restorative needs (cervical diameter)
- consider amount of bone available MD and BL
What is the effect of smoking on implants?- update reference
-impairs innate and adaptive immune response and impairs wound healing
- smokers may suffer 35-75% higher risk of implant failure compared to non smokers
-2-8x higher implant failure
What is the soft tissue attachment around implants vs teeth
Implant-parallel fibers, less vascular/ resistant to connective tissue
Is biologic width different around teeth vs implants
Teeth:
- Garguilo et al 1961 JE 0.97 and CT 1.07 = 2.04mm
Implants:
-Tomasi 2014 JE 1.9 CT 1.7 = 3-4mm
** larger around implants
What force should be used to probe an implant
0.15N
Do implants need KT?
Generally, presence of KT around implants is associated with better implant health
Some studies suggest that implants without KT have healthy peri implant tissues as long as patients have good OH
Thoma et al 2018 (SR)
- improvements in BI and increased marginal bone levels.
Implant failures terminology
Early implant failure: lack of initial integration or presence of infection
Late implant failure: occurs after initial osseointegration, physiological remodelling, and loading
Ailing: biological complications, soft tissue problems, not supporting bone problems
Failing: progressive loss of supporting bone but clinically immobile
Failed: clinically mobile
Reasons for implant failure
- Type IV bone
- Lack of KT, poor OH, occlusal overload, malposition
- Bone overheating, peri implantitis
- Excess cement
- History of periodontitis
- Diabetes
- Former failed site
- Experience
- PPI and SSRIs
Platform switching
The concept refers to placing screwed or friction fit restorative abutments of narrower diameter on implants of wider diameter, rather than placing abutments of similar diameters, this puts the bone further away from the inflammatory cell infiltrate
-better long term preservation of marginal bone
-less vertical bone loss
- minimal bone loss
- long term peri implant health
Types of implant abutment crestal connections
- butt joint
- platform switched
- no interface (tissue level or one body)
Does pulpal status of adjacent teeth or former teeth affect implants?
Retrograde peri implantitis, higher implant failure rates in sites with a history of endo tx and or periapical lesions
** treated active sources of infection and inflammation in adjacent teeth prior to implant placement
How hot can bone get without causing irreversible damage?
44deg- complete repair
47 deg partial bone necrosi
Name technical implant problems
- Implant fracture
- Tooth intrusion
- Intrusion of teeth with telescopic crowns
- Cement bonded breakdown
- Abutment tooth fracture
- Abutment screw loosening
- Fracturing of vaneers
- Prosthesis fracture
Name biological complicatons
- Peri implantitis
- Endodontic problems
- Loss of an abutment tooth
- Loss of an implant
- Caries
- Root fracture
Should implants be connected to teeth?
They can be but should be avoided.
Occlusal overload and implants
peri implant bone loss
mechanical failure of prosthesis
lateral forces and bruxism
lone standing abutments- higher failure rates
increasing implant number and width- load distribution
Animal studies show in the absence of inflammation no association with peri implant tissue breakdown
How to reduce occlusal overload
1.reducing cantilever
2.increasing implant number
3.increasing point contacts
4.monitor parafunctional habits
5.narrowing occlusal table
6.decreasing cuspal inclines
7.progressive lading in pts with 8.poor bone quality
Occlusal guidelines
Full arch fixed prosthesis= bilateral balanced occlusion with opposing complete denture
Group function or mutually protected occlusion with shallow anterior guidance when opposing natural dentition
Overdenture=bilateral balanced occlusion. Monoplane occlusion
Posterior fixed prosthesis= anterior guidance with natural dentition. Group function with compromised canines.
Single implant= anterior or lateral guidance with natural dentition. Light contact at heavy bite and no contact at light bite. Increased proximal contacts
Can dehiscence present at implant placement be effectively treated with GBR?
yes
Are dental implants placed in regenerated bone successful?
yes, but wait 6m
94-96% success
most data says same success as native bone
Implant placement timing
Type 1= immediate
Type 2= Early placement with soft tissue healing (4-8weeks)
Type 3= Early placement with partial bone healing (12-16 weeks)
Type 4= Late placement (>6months)
How much ISQ for immediate loading
60-65
What does ISQ stand for
Implant stability quotient
Primary and secondary stability
Primary stability- achieved at time of placement
Secondary stability- achieved over time with healing
Primary/mechanical stability leads to more efficient achievement of secondary/biologic stability
But high insertion torque may negatively impact bone level stability
Immediate Loading
Immediate -within 1 week
Early- 1 week to 2 months
Delayed- >2months
- no convincing evidence of clinically significant different with implant, prosthesis failure or bone loss with different loading times.
Immediate loading is a practical viable method
Can implants be used for orthodontic anchorage
yes
Survival of transitional implants
90% +
Any difference in guided surgery (bone, tooth , mucosa)
Bone- significantly greater deviation in angle, entry point and apex compared to tooth supported guides
Mucosa- significantly lower deviation in angle, entry point and apex compared to bone supported
No significant differences for any of the outcome measures between mucosa and tooth supported guides.
Advantages of flapless surgery
decreased:
- pain
-analgesic,
-swelling
- chair time
-risk of hemorrhage
-time adapting temp restoration
increase:
- pt satisfaction
Success rate of implants, root amputations and endo tx differ?
NO
implants cost more than keeping teeth
SPTs for implants- protocol
minimum of every 5-6m
