exam 2: cementum Flashcards
cementum is 50-55%:
45-50%:
50-55 organic
45-50 mineral
50/50 split basically
organic compounds in cementum include
type I collagen
proteoglycans
glycosaminoglycans
phosphoproteins
cementum provides attachment to the:
and participate in repair of ____ fracture
PDL
root fracture
cementum provides limited compensation for ________ through continuous apical apposition
occlusal wear
cementum contains less (mineral/organic) than both bone and dentin
less mineral
unlike bone, cementum is __________ and contains no haverian or volkmann’s canal
avascular/not innervated
cementum is thinnest at_________
and increases thickness at the ________ and even more at __________
thinnest at CEJ< mid-root<apex
cells responsible for secretion of organic matrix of cementum are derived from undifferentiated mesenchymal cells that originate in proximal (inner) zone of dental follicle
cementoblasts
-all cells in dental follicle are derived from neural crest cells aka ectomesenchyme
differentiation is initiated with disruption of ___________ allowing the undifferentiated mesenchymal cells to make contact with the adjacent dentin
-dentin matrix growth factors (BMP, FGF, DMP) then induce the differentiation process
hertwig’s root sheath
both indicate incremental growth and run longitudinally within cementum
depositional lines and reversal lines
cementocytes.
- space occupied by cell=
- space occupied by cytoplasmic projections
cell=lacunae
cytoplasmic projections= canaliculi (lines)
PDL fibers passing into acellular cementum
sharpey’s fibers
loss of tooth surface at the cervical areas of teeth caused by tensile and compressive forces during tooth flexure
abfraction
abfraction affects these two cervical areas of teeth
buccal and labial
deep narrow v shaped notch in teeth and common affects single teeth with excursive interferences or eccentric occlusal lodds
abfraction
loss by wear of dental tissue caused by foreign substance (toothbrush)
-lesions are more wide than deep
abrasion
with abrasion, what areas of teeth are affected and what teeth in generally are commonly affected
cervical areas
premolars and cuspids
calcified bodies appearing on or in the cementum and in the pdl
-classified as free, attached or embedded
-response to local trauma or hyperactive occlusion and appear in increasing number with increasing age
cementicle
exposed cementum is hypermineralized which prevents:
reattachment of collagen
exposed cementum facilitates attachment of _____ and______
plaque and calculus
exposed cementum facilitates _____ absorption
endotoxin absorption
excessive production of cellular cementum that generally involves apical 1/3 of root
-can be from trauma of occlusion, periapical inflammation, attrition
hypercementosis
how roots can repair
accessory canals
more apical you go the more canals you have
allow for vascular tissues to reach apical mineralized tissues
(if have crack these can help with repair)
mainly found:
accessory canals
mainly found in furcation
