L10-Periodontics 3 Flashcards
What prevalent connective tissue is Cementum VERY similar to? Name 3 similarities and 1 difference.
Bone.
Similarities:
1. Both mineralized connective tissue. Composed of approximately 50% hydroxyapatite (inorganic) and 50% proteins (organic).
2. Type I collagen is major form of collagen in both, as it is with nearly all connective tissues. Makes up 90% of organic part.
3. Has same Non-collagenous proteins as bone.
Difference:
1. Cementum = avascular; Bone = Vascular
What is cementum’s growth pattern throughout life?
Cementum grows at a slow rate throughout life via surface aposition.
What is the major function of cementum?
To anchor the teeth to the adjacent alveolar bone via periodontal ligament as part of the Attachment Apparatus.
What are 5 common non-collagenous proteins found in cementum? Briefly state function.
- Alkaline Phosphatase: Remove phosphates from many types of molecules
- Osteocalcin: Bone mineralization
- Bone Sialoprotein
- Osteonectin: Binds calcium for deposition
- Osteopontin: Biomineralization & bone remodeling
What type of Radicular cementum fiber is most involved in attaching tooth to bone?
Extrinsic fibers = Periodontal ligament fibers
For single rooted teeth, what is the predominant radicular cementum? What & where is a possible exception? Functions?
Predominant Form (always found in coronal 2/3 of root): Acellular & Extrinsic fibers. Function = Anchorage. Possible Exception: Apical 1/3 may have acellular cementum with Intrinsic or mixed fibers. Function = Adaptation and probably some anchorage of mixed fibers.
ALL coronal cementum takes what form?
Acelluar and Afibrilar; NONFUNCTIONAL
For Multi rooted teeth, what is the common cementum in coronal 2/3? What is common cementum in apical 1/3 & bifurcation? Functions?
Coronal 2/3: Acellular & Extrinsic fibers. Function = Anchorage
Apical 1/3 & bifurcation: ALWAYS CELLULAR with intrinsic of mixed fibers. Function = Adaptation & repair (b/c cellular).
Of what origin are cementoblasts?
Thought to be derived from Follicle Cells. This means they are of an ECTOMESENCHYMAL origin.
What are sharpey’s fibers? Two examples from the attachment apparatus.
When fibers are trapped within a mineralized matrix. Extrinsic fibers are trapped within adjacent cementum and alveolar bone.
How does the developmental timing of all three components of the attachment apparatus (cementum periodontal ligament, and alveolar bone) compare? Briefly describe the direction(s) of periodontal ligament growth.
They all develop concurrently. With the periodontal ligaments initiating growth attached to both the cementum and alveolar bone and growing towards the center where the collagen fibers meet.
How does the orientation of alveolar crest fibers (most cervical perio Lig fiber bundle) oriented in developing tooth compared to mature tooth?
In developing tooth oriented APICALLY from the alveolar crest down to the Developing tooth. As tooth erupts, however, the attachment to the cementum elevates and eventually is oriented CERVICALLY in Mature teeth.
What is the relationship (contour) b/t alveolar bone (coronal rim or alveolar crest) and the CEJ of the teeth? What is in the intervening space?
In health, Crestal bone sits about 2mm apical to CEJ. W/in this 2mm space are the gingival fibers (collagen I of connective tissue), inserted into the cementum, that hold the gingiva to the tooth.
- Alveolar bone rests on what type of bone?
- What is the alveolar process? (What is it dependent upon for development and maintenace?)
- Where is actual Alveolar bone situated? What is unique about it?
- Basalar Bone
- Portion of jawbone that houses teeth and alveoli in which they are contained. Require TEETH for development & maintenance.
- The alveolar bone (alveoli) are the teeth sockets (portion of alveolar process that lines the alveoli. It is a thin cortical bone with numerous perforation (=a cribriform plate). Allows for passage of blood vessels b/t the marrow and PDLs.
