Why can't ameloblasts create enamel in the area where the cementum is?
because the ameloblasts don't have their support structures (stellate reticulum)
In the beginning of the development of cementum______________start laying dentin matrix
odontoblasts
Odontoblasts lay what structure?
dentin matrix
What induces the cells of the dental sac to differentiate into cementoblasts?
newly formed dentin
newly formed dentin____________the cells of the dental sac to______________into cementoblasts
induces
differentiate
newly formed dentin induces the cells of the dental sac to differentiate into what?
cementoblasts
What are cementoblasts?
cells that lay down cementoid or become cementocytes if they get caught in the matrix
The cementoblasts lay their__________and some of them get caught in the matrix and become___________
cementoid
cementocytes
The ends of the periodontal ligament that have embedded themselves into the cementum
Sharpey's fibers
where the cementum and the enamel meet
cementoenamel junction
What are the 3 types of meetings for the cementoenamel junction?
overlap
meet
gap
Why is there overlap in the cementoenamel junction sometimes?
because the enamel was formed first
In what type of cementoenamel junction does the junction feel rough and may be confused with calculus?
overlap
What is the ideal meeting type for the cementoenamel junction?
meet perfectly in the middle
Whay type of cementoenamel junction meeting has a space between the cementum and the enamel, leaving the underlying dentin exposed?
gap
What type of cementoenamel junction meeting can cause dentin hypersensitivity?
gap
name 2 types of lines you can see in cementum repair
reversal lines
arrest lines
lines after cementum resorption, you can tell where the resorption stopped and started laying down new cementum, the cementum had been broken down, but it lays down new cementum
reversal lines
just like retzius lines with enamel and lines of Von Ebner with dentin
arrest lines
Name 2 types of cementum
acellular cementum
celllar cementum
The first cementum to get laid down, it has no cementocytes
acellular cementum
the last cementum to get laid down, it is getting laid at a quicker pace so the cementoblasts get stuck in it
cellular cementum
What happens to the cementoblasts that don't get stuck in the cellular cementum?
they migrate to the periphery of the cellular cementum and wait until they need to make more cementum
What are 3 clinical considerations with cementum?
cementicles
cemental spurs
hypercementosis
cementoblasts start to lay cementoid around cellular debris in the periodontal ligament, it can just float there or start to fuse with the cementum as more is laid
cementicles
the cementoid was laid down weird and caused a spur of cementum to come off at the CEJ, similar to enamel pearls
cemental spur
excessive production of cementum, usually a result of occlusal trauma
hypercementosis
What is the main difference between cementicles and cemental spurs?
cementicles start non-connected to the tooth, and cemental spurs start connected to the tooth
