By

Prof.Dr/Mona Hussein

The science of dental biomaterials

involves the study of the composition

and properties of materials and the way

in which they interact with the oral

environment in which they are placed.

Dental biomaterials may be classified

according to nature into, ceramics,

metals, polymers and composites or

according to use into restorative and

auxiliary materials

WHAT is the THIRD CLASSIFICATION?

I- Metals

Metals are used for making restorations of the

lost tooth structure, prosthetic devices,

orthodontic appliances, and many other

applications where strength and elasticity are

required.

A mixture of two or more metallic elements is

called alloy (Gold alloy &Cobalt chromium alloy)

Metallic restoration

II- Ceramics

Ceramics include a wide variety of

substances such as glass, cement,

refractory (high temp), and many

other materials.

Types of dental ceramics:

Dental porcelain.

Dental cements.

Gypsum products.

Casting investment

Ceramic restoration

Ceramo-metal system

Bridge

III- Polymers

Polymers are synthetic resins.

Types of dental polymers:

Polymeric impression materials.

Denture base materials.

Tooth colored restorative materials.

Polymeric denture base

Esthetic restoration (dental composite)

1-Enamel.2-Dentine.3-Gingiva (Gum).4-Gingival Sulcus.5-Periodontal Ligaments.6-Pulp Chamber.7-Root Canal.8-Apical Foramen.9-Bone.10-Cementum.

1. Enamel:

Is the hardest structure in the human

body.

It forms the outer layer of the crown

It’s the only visible portion of the

crown.

2. Dentine:

Is the main substance of the

crown & the root.

Is yellowish-white in color.

Is sensitive.

SalivaContents:

1- Water.

2- Electrolytes.

3- Mucus.

4- Enzymes.

Functions:

1. Helps in creating the bolus of the food.

2. Amylase enzyme that converts starch into

dextrin.

3. Prevent tooth decay& tooth erosion due to

its buffering properties.

4. Saliva carries ions as calcium,fluoride….

That helps in remineralization.

5. Antibacterial.

The restorative material present in the

oral environment is subjected to:

1. Changes in temperature.(Thermal

properties)

2. Variation in pH.(Corrosion)

3. Occlusal stresses.

4. Solubility and disintegration.

5. Change in color(Optical properties)

Tempromandibular Joint

Functions:

1. The first function is rotation around a

horizontal axis.

2. The second function is translation

where the condyle & the disc move

together anteriorly beneath the

articular eminence.

DENTAL BIOMATERIALS

I -Basic science of biomaterials

• Physical properties

Thermal properties

Optical properties

Surface chemistry

Corrosion

• Mechanical properties

• Basic structure of metals. • Basic structure of polymers.

• Basic structure of ceramics.

II APPLIED BIOMATERIALS