EX2; Periodontium - Cementum Flashcards
What are the three main functions of cementum
attachement
protection
adaptation (to the physiological forces of mastication
What is the composition of cementum
45-50% organic
50-55% inorganic (but can vary)
What makes up the organic component of cementum
90% collagen (90:10 type I to type III)
non-collagenous proteins
ground substance
True or False
Cementum is not vascularized
True
True or False
Cementum does remodel
False; it does not remodel
What is the main difference between cementum and bone
cementum is secreted throughout life, but not normally resorbed
Where is cementum the thinest/thickest
thinest = ~CEJ (vulnerable) thickets = towards the root apex
What are the different types of CEJ joints
overlap (60%)
butt against (30%)
gap (10%)
Primary cementum is composed of what
acellular extrinsic fiber (AEFC)
What does extrinsic refer to in talking about AEFC
the fact that the organic matrix of cementum is secreted by cementoblasts and PDL fibroblasts that do NOT become entrapped in the cementum
Acellular extrinsic fiber cementum is considered to play the most important role in what
attachment
These constitute the mineralized ends of the PDL fibers
Sharpey’s fibers
This consists of collagen fibers oriented parallel to the surface of the cementum with no clear connection to the PDL
cellular intrinsic fiber cementum (CIFC); type of secondary cementum
This comprises the bulk of secondary cementum
mixed fiber cementum
What type of fibers does mixed fiber cementum contain
intrinsic (parallel)
extrinsic (perpendicular)
perpendicular plays the roll in attachment
When is mixed fiber cementum secreted
after and more slowly than the initial wave of secondary cementum, more prominent apically
Where is the secondary cementum most thick
in places in response to occlusal forces
These were originally cementoblasts, entrapped in the mineralizing extracellular matrix
cementocytes
True or False
Cementocytes are actively participating in synthesizing cementum
False; they are not
The rate of cementum formation varies based upon what
environmental factors
An increase in cementum production has been associated with what
attrition
periodontal disease accompanied by pronounced inflammation
Continued deposition of cementum can cause the size of what to become progressively smaller
the apical foramen
Where are the cementoblasts located
lying at the end of the PDL, their long axis parallel to the CEJ
The outmost layer of cementum directly adjacent to the cementoblasts is sometimes unmineralized, and called what
cementoid
These are similarly found in dentin and enamel, apparent in layers in the cementum
growth lines
This is excessively large amounts of cementum deposition (around the root)
hypercementosis (relatively rare)
in the case study; the patient presented with gingival recession but no pain
