Implantology Flashcards
What allows for integration of an implant?
An oxide layer is formed on the surface of the implant that is protective and allows for osseointegration.
Increasing the diameter of an implant has 4 beneficial effects
-Minimizes inter proximal space and potential food impaction and improves oral hygiene
2-Minimizes component fracture
3-Reduces incidence of screw loosening
4-Improves emergence profile of crown
What is more important for an implant, width or length?
Width
Why are rough implants good?
Disadvantage
Rough implants increase surface area and bone-implant contact
-This leads to faster and strong osseointegration compared to machinee surface.
-Plaque retention, and peri0implantitis
External hex design problems?
1-Traditional design with butt-joint connection
2-Abutment screw loosening is probelmeatic
Internal hex design?
incorporates an antirational feature (hexagon, tripod, morse taper, internal grooves)
What is platform switching
2 points
-Use of a narrower restorative abutments on a wider implant body
-Shown to decrease crestal bone resorption by preventing migration of epithelium past the implant-abutment interface, enhancing the connective tissue-osseous attachment in the crestal area.
Why are tapered walls of implants important?
1-Allows compression of bone in poor-quality sites and distributes forces into surrounding bone.
2-Facilitates placement into anatomically constricted sites (buccal concavities, adjacent teeth)
Parallel wall versus tapered wall implants?
-In sites with poor bone quality, under preparation with tapered implant can achieve greater primary stability compared to that with parallel wall implant.
Pitch of an implant
Benefit?
Distance between adjacent threads
More threads, greater surface area per implant.
What kind of threads are better for soft bone?
1-Deeper threads because it increases surface area
What type of threads allows or easier placement of an implant in hard bone
Shallow threads
Name 4 risk factors associated with implant failure
1-Periodontal Disease
2-Smoking
3-Prior radiation treatment
4-Diabetes
Can pts with parafunctional habits have implants?
Yes, however additional implants are needed to reduce overload, or a night guard is necessary.
What is the vertical space required for a fixed restoration?
Cement retained (8 mm minimum)
Screw retained (6 mm minimum)
1 mm occlusal metal restoration (2 mm for porcelain)
5 mm abutment for cement restoration (1 mm sub gingival margin= total 6 mm)
2 mm soft tissue attachment
Ideal vertical space for implants
9-10 mm in posterior
10-12 mm in anterior
If >12 mm, teeth will be elongated and may required addition of pink tones in aesthetic areas.
Implants should be placed how far from adjacent tooth and adjacent implant.
1.5 mm from adjacent tooth to prevent bone loss
3.0 mm from adjacent implant to prevent bone loss
Minimum amount of buccal/lingual bone
1 mm
How many mm apical to gingival margin for appropriate emergence profile of crown?
3 mm
In a healthy periodontium the facial margin of the alveolar crest lies approximately 2 mm apical to the gingival margin, which courses near to the cementoenamel …
How many mm palatal to buccal walls in esthetic zone for appropriate crown emergence and to prevent buccal bone loss should an implant be placed
2 mm
How many mm above the IAN should an implant be placed
2 mm
How many mm anterior to mental Forman to avoid anterior loop of the mental nerve should an implant be placed
5 mm
Type I bone
Predominant cortical bone (anterior Mandible)
-overheating potential
-tapping of bone recommended to facilitate implant placement
Type II bone
Thick cortical bone and dense cancellous bone (mandible, anterior maxilla)
Type III bone
Thin cortical bone and dense cancellous bone (maxilla)
Type IV bone
-Predominantly cancellous bone (posterior maxilla)
-poor bone quality leads to lower success
-Consider osteotome technique to compress denser bone laterally next to implant
-Consider under preparation of site
What is the best bone for implant placement?
Type II-Thick cortical bone and dense cancellous bone (mandible and Ant maxilla)
-and-
Type III-Thin cortical bone and dense cancellous bone (maxilla)
Why is thick gingival biotype important
Probe is not visible
-Greater soft tissue stablity
-More predictable healing
-Less gingival discoloration from titanium show,
-Less gingival recession
Osseointegration
Direct structural and functional connection between bone and the surface of an implant that can survive normal loading conditions
What is the osseointegration window for implants
3 months in mandible and 6 months in maxilla but this has improved overtime.
T/F: mechanical stability is high after surgery and declines after time
True
What is the weakest time for implant placement
2-4 weeks
Osteoconduction
Recruitment of osteogenic cells to the implant surface via a matrix
Contact osteogenesis:
De novo bone formation on the implant surface
Distance osteogenesis:
New bone formation on the walls of the osteotomy site toward the implant surface.
Implant success:
Absence of implant mobility, per-implant radiolucency, and symptoms (pain, infection, numbness); crystal bone loss <0.2 mm per year following the first year of function
Speeds must be less than what to prevent overheating of bone
2000 rpm
Thermal necrosis occurs at what temp for implants
47 degrees Celsius
116.6 degrees F
How much keratinized tissue should be left behind and why
2 mm
-Prevents functional stresses, improves hygiene, and avoids complications of mobile tissue including chronic inflammation, irritations and peri-implantitis
What is required to place an immediate implant with a provisional prsthesis
primary implant stability with torque of >35 Ncm
What are immediate implants place?
Develops and maintains soft tissue architecture in esthetic zone
What is a Fixed PRM bridge and where are implants placed.
Fixed porcelain fused to metal bridge which requires 6-8 implants
Primary site-1st molar ( 2 implants_
Seoncdary site -Canine - (2 implants)
Tertiary site - Lateral incisors or 2nd premolar (2-4 implants.
What is a hybrid prosthesis?
A fixed-detachable prosthesis, profile prosthesis
What is the vertical space required for a fixed prosthesis?
15 mm from soft tissue to planned occlusal plane, more space allows for thickening of prosthesis, more strength.
2 mm: space under bar for hygiene
8 mm: cast framework
2 mm: acrylic
3 mm: teeth
AP spread
distance between anterior and posterior implants measured from midline of arch and number of implants
What is the measurement to of AP spread to prevent cantiliver
Less than 1.5 times the AP spread
Spread them apart to achieve first molar resotration
Which of the following has the least AP spread?
Square-shaped arches, least AP spread
V-shaped arches, most AP spread
Treatment plans regarding Rescue’s 1,2,3 bone concept
How far apart should over denture implants be?
At least 20 mm
What is the highest implant failure associated with
Maxillary overdenture of 4 implants connected with a bar due to higher loads
What are the vertical height requirements for an overdenture
minimum of 12 mm from soft tissue
-1 mm for below bar for hygiene
-3 mm for bar and Hader clip (or 5 mm for bar and O ring)
-8 mm for tooth
Combination syndrome
Atrophy of the edentulous anterior maxilla that develops in patients with a partially edentulous mandible and preserved anterior mandibular teeth. Treatmetn includes placing implants in the posterior maxilla to distribute forces to posterior occlusion nd off the anterior maxilla
All on 4 principles
-Maximize angled spread, most anterior and posterior implants hold all the load
-Angle to avoid vital structures like the sinus and the mental nerve.
When is an all on 6 used? (3 pts)
1-Large arch form
2-larger ridge discrepancies
3-higher potential failure (maxilla, smoking, diabetes, periodontal disease, bruxism)
Zygomatic implants are used with what kind of prosthesis
A hybrid prosthesis.-fixed detachable prosthesis
How much apical bone is required for primary stabilization?
2 to 3 mm of apical bone is required for primary stabilization
Are single implants in immediate restorations left in or out of occlusion
Left in infraocclusion
Primary stability of ____ NcM is mandatory for immediate implants.
30-35 Ncm
Allografts or autografts have greater shrinkage rate?
Allografts have greater shrinkage rate
Subepithelial connective tissue graft can thicken the gingiva by how much?
Can thicken gingival tussle by 3 mm in order to prevent recession and subsequent metal show.
Osteoinduction:
Growth factos stimulate mesenchymal cells to differentiate into osteoblastic lineages
Osteoconduction
Bone graft acts as a matrix for bone growht
Osteogenesis:
Transplated osteoblasts and periosteum produced now bone
Autogenous bone
-Gold standard
-Osteogenic, osteoinductive, and Osteoconductive
Sites for autogenous bone:
Corticocancellous: Tibia, iliac crest
Cortical: Cranium, mandibular ramus, mandibular symphysis
Allograft:
Contains what property?
Human bone graft
Osteoconductive-bone graft acts as a matrix for bone growth
Xenograft or allograft-which resorbs slower?
Xenograft
What quality does rhBMP have?
Osteoinductive, member of TGF (transforming growth factor) superfamily
-Aloows 4-6 months of bone healing before implant placement.
Ridge Augmentation options-Think of 5
1-Onlay
2-Ridge split
3-Mesh
4-Sandwich osteotomy
5-Distraction osteogenesis
How can you augment the vertical height of the alveolar crest (2 methods)
1-Mesh
2-Sandwich osteotomy
How can you augment the width of the alveolar crest? (5 methods)
1-Only
2-Ridge split
3-Mesh
4-Sandwich ostetomy
5-Distraction osteogenesis
What is an only graft
Fixation of cortical graft with screws; potential for resorption
What is a ridge split require?
at least 3 mm of ridge required.
How is a sandwich graft performed?
Interpositonal graft with superior plating of superior segment
What is the rate at which distraction can occur?
5-7 day latency perio
0.5 mm 2 x day ( 1mm day)
2-3 months: Consolidation
Tooth extraction leads to bone loss in what dimension
Buccolingual (50%) in 6 months
Socket healing process,, 4 steps to month two
Bone remodeling:
Turnover of bone characterized by osteoblastic formation balanced with osteoclastic resorption.
Extraction sockets that benefit from bone modeling
-Sockets with wall defects and thin buccal bone
Guided bone regeneration
Placing a barrier membrane to prevent invasion of nonosteogenic cell populations from surrounding soft tissues.
What is the average sinus cavity volume for adults?
14.75 mL (ranges between 9-20 mL)
Thickness of sinus membrane
0.13 to 0.50 mm
Where does the maxillary sinus drain?
By ciliated epithelium to an osmium in the middle meatus of the nose.
How much bone is needed to simultaneously place an implant with a sinus graft
3-5 mm, and you need priamry stability
What is the summer technique
Osteotome use to elevate the floor of the sinus, achieve elevation of < 2 mm
Which approach for sinus grafts depending on availability of bone.
Peri-implantits most often occurs in what kind of restorative solution
overdentures
Normal bone loss of implants
-Less than 1.5 mm at year 1 and <0.2 mm per year thereafter
Peri-mplantitis
-Mucosal inflammation with los of supporting bone
Which bacteria are associated with peri-implantitis
Similar to periodontitis:
GN, anaerobic bacteria
-Aggregatibacter anctiomycetemcomitans
-Porphymonas gingivalis
-Prevotella intermedia
What surgical aspects can cause an implant to fail.
-Overheating bone, poor primary stability, dehiscence of thin bone.
How can you remove bacteria biofiom to improve per-implantits
-Saline, abrasive pumice, citric acid, Preidex, Hydrogen peroxide, tetracycline, lasers
Can you bone graft a peri-implantitis site.
Yes, you can but it requires one to fill osseous defect and use guided bone regeneration.
What are the 6 risk factors associated with implant failure.
