Alveolar bone Flashcards
What are the layers of a tooth?
Enamel >PDL>Cementum> dentine > Pulp
What is the alveolar bone?
forms socket wall consists of inner cortical plate of alveolar process
What is the major protein matrix of the bone?
Collagen
What are the 4 Connective tissues in periodontium?
Cementum
Alveolar bone
Periodontal ligaments
Lamina propria
Which connective tissues are calcified?
cementum
alveolar bone
which connective tissues are non calcified?
periodontal ligaments
lamina propria
What is bone made of ?
65% = inorganic HAP 23%= organic e.g. Collagen type 1, calcified tissues 12%= water
is the mandible bone chem/structurally same as ant other bone in body?
YES
What are the bone structures?
COMPACT/CORITCAL
CANCELLOUS
What is cancellous bone?
spongy bone- forms core of bone
what are the types of compact bone?
Parallel plates
Haversian system
What are lamellae ?
parallel plates of bone on perio/endosteal surface
What is Haversian system?
when lamellae form concentric circles
how is mature haversian bone formed?
lamellae remodel and removed and form around central canal
what happens when haversian bone is laid down?
vascular canal smaller and mineral more dense
What is above/below “line” that’s level to root apices?
alveolar process and body of mandible below
what is the bone arrangement in mandible body?
compact bone outside and cancellous interior
what is bone arrangement of alveolar process for incisor?
little cancellous bone and process formed from fusion of interior and exterior cortical plates
what is bone arrangement of alveolar process for back tooth?
cancellous present in alv. process
what does the inner cortical plate form?
socket wall>cancellous bone> outer cortical plate
what is attached to alveolar bone?
periodontal ligament
what penetrates alveolar bone from demineralized periondontal ligaments?
Sharpeys fibres
what between sharpeys fibres?
Osteoblasts
what are osteoblasts
form new bone matrix
what is osteoid?
unmineralized pre bone at PDL and Bone junction
what is immature bone with sharpeys ?
Bundle bone
what happens to sharpeys when bone matures
fibres are now TRANSALVEOLAR and insert into adjacent tooth root
what happens when teeth are lost ?
alveolar bone is reabsorbed
what happens to alveolar crest when teeth absent?
reduces due to plasticity
how is bone reabsorbed ?
osteoclasts break down bone
What do osteoblasts have
RER
What are Osteocytes?
osteoblasts entombed in bone matrix
what are canaliculi?
channels so osteocytes can contact others in PDL
What are osteoclast?
bone degradation found in Howships lacuna
what is howships lacuna?
depression in bone
what is border of degrading bone with osteoclasts?
brush boarder since microvilli
what do microvilli help for degrading bone?
Inc. SA for pumping H+ and enzymes into matrix
what do protons do for degrading bone?
lower ph so dissolve mineral
what do enzymes do for degrading bone?
matrix degraded after minerals gone
what is the annular zone?
around brush boarder where degradation localized and low ph here
what is resting line?
smooth line where previous bone depostion
what is reversal line?
where resorption reversed to formation
-osteoclasts move away and osteoblasts enter so new bone laid down
