Study sets, textbooks, questions
Upgrade to remove ads
endo lecture 2
Terms in this set (73)
what are some periradicular tissues?
2: periodontal ligament
3: alveolar bone
where do the pulp and the periodontum blend?
the pulp and periodontum blend at the apical foramen and lateral canals
-it is at these sites that disease in one tissue can extend and involve one another
what serves as the attachment for PDL fibers?
cementum (bone like tissue)
is cementum more resistant to resorption than bone?
what type of cementum is located in the apical half of the root?
what type of cementum is located in the coronal half of the root?
what is the narrowest part of the canal?
apical cemento-dentinal junction
what is the distance from CDJ to opening?
0.4mm to 0.5mm
-distance can increase with age
what supports tooth in socket and absorbs forces of mastication?
what are the types of innervation of the PDL?
sensory and sympathetic nerve fibers AND mechanoreceptor (proprioceptive) fibers
true or false: the PDL has a rich blood supply
what is the first tissue to be destroyed by endo disease?
what is the last tissue to heal?
what is the source of pain to PDL?
what is the source of pain to the pulp?
hot and cold
what occurs in induction?
the pulp induces odontoblasts to differentiate and produce dentin
-induction is the most important function of the pulp
what are the types of dentin?
what is primary dentin?
first layers of dentin to be deposited as the tooth is forming
what is mantle dentin?
the very first layer of primary dentin to be deposited
what is secondary dentin also referred to as?
what is secondary dentin?
deposited throughout the life of the tooth as a response to physiological and functional stimulus
what is tertiary dentin also known as?
reparative or irritation dentin
how fast does tertiary dentin form?
describe dentinal tubules present in tertiary dentin
very few and irregular dentinal tubules
describe the mineralized matrix of tertiary dentin
low mineralized matrix
is it possible that tertiary dentin be incomplete?
yes, tertiary dentin can be incomplete and many times incapable of preventing plural disease
what are the main theories of dentin sensitivity?
1: dentin innervation theory
2: transduction theory
3: hydrodynamic theory
what is the dentin innervation theory?
nerve endings penetrate dentin
-direct mechanical stimulation of these nerves will initiate an action potential
what part of the dentin is innervated?
nerves are confined to the inner 1/3 of dentin
what are some arguments that combat the dentin innervation theory?
1: nerves confined to the inner 1/3 of dentin
2: pain producing substances such as bradykinin fail to induce pain when applied to dentin
3: bathing dentin with local anesthetic solutions do not prevent pain
have nerves been demonstrated to penetrate into dentin
what is the transduction theory?
postulates that odontoblasts can transmit a mechanical stimulus and transfer it as a signal to a close by nerve ending
-thereby turning it into a painful stimulus
what are some facts that support the transduction theory?
-odontoblasts are derived ed from the neural crest
-odontoblastic processes extend into dentinal tubules
-dentinal tubules found to extend to DEJ
-odontoblasts closely associated with nerve terminals
what is the hydrodynamic theory?
rapid fluid movement in dentinal tubules results in distortion of nerve endings which will then start an impulse
-explains hot, cold, air, sweets sensitivity
explain the process of the hydrodynamic theory
-heat will expand the dentinal fluid
-cold will contract the dentinal fluid
-sugar will move dentinal fluid outward through osmosis
-air will move dentinal fluid outward and can aspirate odontoblasts into dentinal tubules
what can be mineralized to reduce dentin sensitivity?
what is peritubular dentin?
dentin that contains mineralized dentinal tubules
-results in decreased sensitivity
what can plug up an exposed dentinal tubule?
an accumulation of minerals, organic material, fluorides and sometimes bacteria
how do desensitizing toothpastes work?
by occluding dentinal tubules with substances such as strontium chloride
what are pulpal calcifications?
pulp tissue that becomes calcified or mineralized deposits in pulp tissue
what are pulpal calcifications commonly referred to as?
what are the classifications of pulp stones?
true pulp stones: resemble dentin
false pulp stones: concentric rings in amorphous mass of calcified tissue (most are false)
--> can also be attached or free
what are some facts about pulp stones?
-can occur in young or old people
-46% of undergrads had one or more pulp stones
-nothing to do with pain, not a pathologic condition, BUT if need a root canal, it makes it harder to find canals
-linear diffuse calcifications
-can be impediments to Endodontic treatment
true or false: there is an afferent and an efferent side to pulpal circulation
list pulpal microvasculature
where do afferent blood vessels enter the pulp?
enter though the apical foramen and then branch into smaller metarterioles, pre-capillaries, and capillaries
the extensive, unique, and complex vascularity of the dental pulp supplies...
nutrients essential for dentin formation and for cell survival
what is the source of dentinal fluid?
what are the 3 distinct structural layers of arterioles?
1: adventitia (connective tissue)
2: muscular layer (vasoconstriction)
3: endothelial layer (permeability)
what are meta-arterioles?
arterioles that become small
what layer do meta-arterioles lose?
connective tissue layer (adventitia)
what layer do capillaries have?
only have an endothelial layer
what occurs at the endothelial layer of capillaries?
fluid interchanges, nutrients go out of circulation to cells, collection of waste products from cells where they go into the efferent part of the circulation
what is the terminal capillary network (TCN)?
extensive branching of capillaries in sub-odontoblastic zone (cell free zone)
what are efferent blood vessels?
they constitute exit side of pulpal circulation, removal of waste products, venues, lymphatics
do venules have a muscle layer?
are venules capable of vasoconstriction?
no because they do not have a muscle layer
along with lymphatics, what constitutes the efferent part of the pulpal circulation?
how do we know that lymphatics are present within the pulp?
research demonstrates there is drainage from the pulp into regional lymph nodes
what are the neural functions of pulp?
sensory function and vasomotor function (vasoconstriction)
describe the sensory pulpal innervation
-branches of the mandibular and maxillary divisions of trigeminal nerve
-enter teeth foramina and progress coronally and peripherally
-nerves branch extensively subjacent to cell rich zone (plexus of Rashcow)
-nerves loose myelin sheet at cell rich zone
what types of sensory nerves are present in the pulp?
A-delta and C fibers
are A delta fibers myelinated?
yes, they are larger myelinated nerve fibers
what is the speed of conduction of an A delta fiber?
what is the threshold of excitability of an A delta fiber?
where are A delta fibers located in the pulp?
located peripherally on the pulp
what type of pain are A delta fibers associated with?
initial momentary sharp pain in response to external stimuli
what type of myelination do C fibers have?
smaller, and unmyelinated nerve fibers
what is the speed of conduction of a C fiber?
slower speed of conduction
what is the threshold of excitability of C fibers?
where are C fibers located in the pulp?
located deeper in the pulp
what type of pain are C fibers associated with?
continuous, constant throbbing pain related to pulpal tissue damage and the inflammatory process
why are young teeth less sensitive than adult teeth?
immature teeth do not have a well developed sensory system
-could obscure a pulp test taken on a child
Other sets by this creator
endo lecture 1
comparative dental anatomy
dental anatomy final
Recommended textbook solutions
Clinical Reasoning Cases in Nursing
Julie S Snyder, Mariann M Harding
The Human Body in Health and Disease
Gary A. Thibodeau, Kevin T. Patton
Mathematics for Health Sciences
David D Celentano, Moyses Szklo