Pulp Therapy and Trauma Flashcards
(129 cards)
What is the origin of pulp?
Mesenchymal tissue
Dentin components
Inorganic: hydroxyapatite
Organic: mostly type I collagen, also type V collagen, dentin sialoprotein
Primary dentin
Tubular dentin formed before eruption
Includes mantle dentin
Secondary dentin
Regular circumferential dentin formed after tooth eruption
Tubules continuous with primary dentin
Tertiary dentin
Dentin in response to irritation
Reactionary versus Reparative Dentin
Reactionary: formed by original odontoblasts, continuous with secondary dentin
Reparative: original odontoblasts died, dentin formed by new odontoblast-like cells and is not continuous with secondary dentin
Molecular basis for odontoblast stimulation
TGF-B: sequestered into dentin matrix during tooth development
Growth factors interact with pulp to cause proliferation of mesenchymal cells and making of dentin
Calcium hydroxide has a similar effect - high pH causes demin and releases TGF-B to make reparative dentin
Mild insult to dentin
Cavity preparation without pulp exposure
Caries lesion into dentin
Severe insult to dentin
Chronic pulp inflammation due to deep caries
Dry cutting
Endotoxins from bacteria in deep caries
Mechanical exposure of pulp
Presence of bacteria increases extent of pulp inflammation
Remaining Dentin Thickness (RDT)
<0.25mm results in more severe pulp inflammation
Best to have more than 0.5mm
- when greater than 0.5mm, reactionary dentin
- when less than 0.5mm, reparative dentin
What is the most frequent cell type of the pulp?
Fibroblasts
Capable of generating odontoblast-like cells
What cells are in the pulp?
Fibroblasts Odontoblasts Histiocytes Macrophages Granulocytes Dendritic cells T-lymphocytes Plasma cells Mast cells (rare in healthy pulp)
Structural proteins of pulp
Collagen (type I and III main subtypes)
Elastin (arterioles)
Neuropeptides of the pulp
Calcitonin gene related peptide (CGRP) is most common - involved in induction of neurogenic inflammation
Substance P
Neuropeptide Y
Neurokinin A
Vasoactive intestinal peptide
Correlation between clinical findings and histology of pulp?
“Currently very little or no correlation exists between clinical diagnostic findings and the histopathologic status of the pulp” Fuks et al. 2018
Diagnosis of pulp status
Medical history Dental history History of pain (and type) Clinical Exam Radiographs
Types of nerve fibers in pulp
A fibers (myelinated) C fibers (unmyelinated)
A fibers of pulp
90% are A-delta (10% A-beta)
Innervate dentin tubules and stimulated by fluid movement
Rapid, sharp pain
Increase in number over time after eruption
C fibers of pulp
3-8X more common than A-delta
Thinner
Dull, aching pain
Nerve Plexus of Raschkos
Myelinated nerve fibers located in cell rich zone
Monitors painful sensation
Mediates inflammatory events and tissue repair
EPT
Not reliable in young children
Stimulates A fibers
Cold Testing
Excites A fibers (not C)
No evidence that cold testing injures pulp
Hydrodynamic theory
Fluid movement in dentinal tubules is translated into electric signals in axons that innervate dentinal tubules
Increased pressure = increased nerve impulses from pulp
A fibers mainly
Pulpitis Pain
C fiber activation from pulp tissue injury
Prolonged pain indicative of irreversible pulpitis