D2 Biomaterials Lecture 2: Dental Implants

How do implants help with dentures?

Anchor in place

How do implants help bone?

Strengthen bone by loading

How do implants help other teeth?

Avoid high load and wear

What part of the implant is the titanium screw that serves as a root replacement?

Implant

What part of the implant is the stump that holds the crown?

Abutment

What part of the implant is the visible part of the implant restoration?

Crown

What is needed to anchor the implant?

Sufficient thickness of jawbone

What must be done before implanting if there is not sufficient thickness of jawbone?

Bone grafting

How long should you wait after an implant before applying force in a dental prosthesis?

6 months

What type of implant is implanted on top of the bone surface without penetration of bone?

Subperiosteal implant

When are subperiosteal implants usually used?

Insufficient bone

What type of implant extends completely through the mandible and penetrates both the inferior and superior cortical plates?

Transosteal Implant

What is the transosteal implant limited to?

Anterior mandible

What is the most common type of implant?

Endosseous implant

What is the type of implant that is placed directly into the mandible or maxilla?

Endosseous implant

What shape of endosseous implant is the most effective?

Screw-shaped

What is the most commonly used implant metal?

Titanium

What are the three advantages of titanium?

1. High strength

2. Corrosion resistance

3. Biocompatibility

What is the integration of the implant within host bone that makes a strong interlock with surrounding bone?

Osseointegration

What two techniques on implant surfaces could help with osseointegration?

1. Sandblasting

2. Acid etching

What are the two benefits of osseointegration?

1. Support dental prosthesis

2. Transfer stress through bone interface

What are the three requirements for osseointegration?

1. Healthy bone

2. < 10 nm space between implant and bone

3. Interface survives load

What is the term when the surface of the implant becomes chemically fused to the surrounding bone?

Biointegration

What is the benefit of bioactive materials in implants?

Colonization by osteoblasts

What is the tissue response to bioactive materials that causes chemical bonding to the implant?

Osteoconduction

What is the term for when bioactive materials form a direct chemical bond with natural bone?

Biointegration

Why can't bioactive materials be stand-alone implants?

Too brittle/weak

How are bioactive materials applied to implants?

Thin film coatings

What happens to bioactive coatings over time?

Resorbs

What is the term for the highest stress to which a material can be repeatedly loaded without failure?

Endurance limit

What are the three types of forces that affect implants?

1. Tensile

2. Compressive

3. Shear

What force to the interfacial bone is caused by smooth implants?

Shear

What force to the interfacial bone is caused by screw-shaped implants?

Compressive

What are the two benefits of porous surface implants?

1. Accept bone ingrowth

2. Increased surface area/interlocking

What are the three causes of premature failure in implants?

1. Cyclic bending loads

2. Bruxism

3. Angled abutments

What type of loading should be avoided in implant designs?

Off-axis

Are successful implants mobile or immobile?

Immobile

What is the radiographic sign of a successful implant?

No radiolucency

How can drilling cause necrosis and inflammation that lead to implant failures?

Overheating

What two things should be inspected on the site of the implant before placement?

1. Quantity of bone

2. Quality of bone

What habit must patients have in order to consider implants?

Good hygeine

Why does the anterior mandible have a high success rate for implants?

Has the greatest trabecular bone