Implants

Question 1

What is Osseointegration? Give the 2 stages

Answer 1

• Direct functional and structural connection between load bearing implant and living (organised) Bone

Primary osseointegration
- Implant anchored in bone due to frictional forces provided between osteotomy and dental implant design features

Secondary osseointegration
- Functional connection between bone and dental implant as bone grows onto surface of dental implant

Question 2

Give the sequalae of healing following implant insertion

Answer 2

• Granulation tisse grows in the wound chamber days after
• Immature (woven bone) grows weeks after
• Mature lamellar bone (months after)
• 4 weeks there is collagen orientation present
• 6-8 weeks mature tissue attachment

Question 3

Describe the supra-crestal soft tissue and sub-crestal tissue of a tooth and an implant

Answer 3

Tooth supra-crestal
- More fibroblats
- Less collagen
- Collagen fibres orientated perpendicular to root surface

Implant Supra-crestal
- More collagen
- Less fibroblasts
- Collagen fibres parallel to implant crown

Tooth Sub-crestal
- Tooth anchored to bone by PDL complex (bone/PDL/cementum)
- Capable of physiological adaptation
- Resilient to tissue attachment

Implant sub-crestal
- Impalnt anchored to bone by direct functional contact
- No physiological adaptation present
- Rigid connection

Question 4

Give the 3 materials used for dental implants

Answer 4

• Titanium
• Titanium zirconium
• Ceramic (Yittra stabalised zirconia)

Question 5

What are the primary aims of dental implant?

Answer 5

• Replace missing teeth with aesthetic , functional and predictable restoration
• Low rate of complications during healing and maintenance period
• Long term stability

Question 6

What medical history made reduce the survival rate of dental implants?

Answer 6

Meds
- SSRIs
- PPIs
- Bisphonates
- Steroids
Radiotherapy
Poorly controlled diabetes

Question 7

How does smoking affect implant placements?

Answer 7

• Increased risk of implant failure in pts who smoke
• Increased risk of peri-implantitis in pts who smoke

it affects the
- Vascularity of tissues (increased chance of atherosclerosis - blocks)
- Fibroblast and osteoblast function (inhibits their effect so poorer wound healing and less bony deposition)
- PMN function decreas - increased risk of pathogen invasion

Question 8

What is high, medium and low smile line defined as?

Answer 8

High >2mm St show
Med <2mm ST show
Low Lip covers >25% teeth

• Impacts visibility of implant

Question 9

How does infection at site of implant placement affect the success?

Answer 9

• Decreases success and survival rate so wait 4-6 weeks for infection to clear
• Increase risk of peri implant periodontitis

Question 10

What local anatomy do you need to be careful of when placing implant?

Answer 10

Maxilla
- Max sinus
- Nasal floor
- Naso-palatine canal
- Infra-orbital nerve

Mandible
- IAC
- Mental foramen
- Incisive canal
- Lingual perforating vessels
- Submandibular fossa

Question 11

What positioning measurements do you need to have to place an implant?

Answer 11

• 1.5mm Mesio-distal either side adjacent teeth
• > 1mm bone labially or >2mm HT/ST labial to implant

Question 12

Give some risk factors that place pt on high risk for failure

Answer 12

• Reduced immune systme
• Heavy smoker >10 a day
• High aesthetics demand
• High lip line
• Thin gingival biotye
• Triangular shape of tooth crown
• > 7mm bone level to adjacent tooth
• Acute infection in site
• 2 or more teteh width of edentulous space
• ST defect
• Vertical bone deficiency