Dental Structures

enamel

• covers the crown

• hardest substance

• protects the tooth from chewing and acids

• no blood vessels, cant regenerate

• made by ameloblasts

ameloblasts

• specialized cells that form enamel

• only happens before eruption

• cells cant remake it

Dentin

• under enamel

• makes up most of the tooth

• cushions enamel so it doesn’t crack

• made by odontoblasts

dentinal tubes

fluid filled tubes in the dentin that if exposed lead to tooth sensitivity

odontoblasts

• specialized cells that make dentin

• cells stay alive throughout life

What are the different types of dentin and what are they responsible for?

• Primary dentin - is the main dentin formed during development and is what your tooth is mainly made up of after being born

• Secondary Dentin - comes after the root forms and develops as you get older, makes the pulp chamber smaller and protects it

• Tertiary Dentin- emergency dentin that forms when injury or cavity occurs

Pulp

• soft tissue inside of the tooth

• contains nerves, blood vessels

• in charge of sensation and nutrition

cementum

• covers the root

• anchors PDL

• softer than enamel and dentin

Periodontal Ligament (PDL)

• tiny fibers between the cementum and alveolar bone

• holds the tooth in the socket

• absorbs chewing force so the tooth doesnt hit the bone

What are the types of fibers in the PDL (collagen fibers)

• Oblique fibers: prevents the tooth from being pushed into the socket

• Horizontal fibers: stabilizes the tooth side-to-side

• Apical fibers: anchors root to bone

• Interradicular fibers: found in multi rooted teeth like molars and pre molars- goes from cementum of one root to the other root

Interdental septum

the alveolar bone between adjacent teeth

Alveolar bone

• the bone surrounding tooth sockets

• supports teeth and anchors the PDL fibers

• remodels with braces + tooth movement

Root

• inside the bone

• covered by cementum

Anatomical crown

• portion of the tooth that is covered by enamel

• includes the part that is under the gums too

Clinical crown

• part of tooth that you can see in the mouth

• this changes depending on gum position, recession and eruption

odontoclasts

• specialized cells that break down root, dentin and cementum

Osteoclasts

• specialized cells that break down bone

Osteoblasts

• specialized cells that build bone