Intro Flashcards
how does universal notation system work?
starts upper R, goes across the top, drops down to the L, then comes back to the lower R for 32 total teeth (including 3rd molars)
numbering system for primary teeth that hang around later into life
keep the alphabetic numbering system, unless they are implants
clinical crown
the visible part of a tooth above the gumline - can change throughout a person’s life!
anatomical crown
what you think of when you think of a proper crown, separated from the roots by the CEJ. only change to it is wear on the top of the tooth
root
part of the tooth embedded in the alveolar process and covered by cementum
alveolar process
the bone that holds the teeth in the jaw. roots are covered by cementum.
apex
the tapered end of a root tip
apical foramen
the opening at the root tip where nerves and blood vessels enter and exit the tooth
layers of the teeth from external to internal
enamel, dentin, pulp
neck of the tooth
the CEJ area
gingiva
gums
helps attach the root to the surrounding alveolar process
periodontal ligament
layer of the tooth that covers the roots
cementum
enamel
- makes up the anatomic crown - not on the root!
- hardest material in the human body
- incapable of remodeling and repair, but can remineralize
- is somewhat dynamic - constantly undergoing equilibrium process - exchange of ions with saliva
benefit of fluoride
makes enamel more resistant to acid attack
composition of enamel
95% calcium hydroxyapatite in a crystalline structure, 5% water and organic material
cells that form enamel
ameloblasts - ectodermal epithelial cells
dentin
- just deep to the enamel, makes up the bulk of the volume of the tooth
- covered by enamel on crown and cementum on root
- not as hard as enamel - 70% calcium hydroxyapatite
- exposed dentin via dentinal tubules is sensitive to temperature/pressure
- covers pulp
DEJ
dentinoenamel joint - where the dentin and the enamel meet. not visible clinically unless enamel has been removed.
cells that produce dentin
odontoblasts from the mesoderm. they are still alive after the tooth erupts, so they create more dentin in response to trauma - one of the teeth’s only protective mechanisms
dentinal tubules
pores in the dentin that travel from the pulp to the border of the enamel or cementum
cementum
- covers root of the tooth
- covers the dentin and meets the enamel at the cemento-enamel junction (CEJ)
- primary function is to anchor the tooth to the bony socket with attachment fibers (periodontal ligament)
- softer than dentin - 65% calcium hydroxyapatite - about as hard as bone - most susceptible to decay
- develops from the dental sac (mesoderm) and is produced by cementoblasts
cells that create cementum
cementoblasts, from the dental sac (mesoderm)
CEJ
cementoenemal junction - separates the enamel of the crown from the cementum of the anatomic root. aka the cervical line