Pulp Flashcards
Young pulp
Contains high quantities of cells and fine collagen fibrils
Older pulp
Opposite of young pulp
May contain calcified structures (pulp stones/ diffuse calcifications)
General characteristics of pulp
Limited regenerative capabilites- does contain viable cells
Pulp size decreases w/ age due to continuous dentin formation
Foramen size decreases w/ age due to continuous cementum formation & causes offset position and/or obliteration
Embryonic origin of pulp
Ectomesenchyme/mesenchyme- neuroectoderm
Neural crest cells of the head give rise to the dental papilla
Cells that comprise pulp
Fibroblasts Odontoblasts Mesenchymal cells Pericytes/Rouget cells Dendritic cells Macrophages Extravasated WBC's
Fibroblasts
Synthesize collagen and amorphous/ground substance
Odontoblasts
Synthesize dentin (collagen, ground substance, calcium hydroxyapatite)
Mesenchymal cells
Differentiate into collagen, ground substance and calcium hydroxyapatite
Pericytes/Rouget cells
Associated w/ capillaries (contractile capabilities)
Dendritic cells
Phagocytize antigens, transfer these to macrophages
Macrophages
Complete antigen elimination process
Extravasated WBC’s
Leukocytes- neutrophils, eosinophils, basophils
Lymphocytes- B-cells, t-cells, NK cells
Intercellular substance in pulp
Gelatinous matrix- collagen fibers & some reticular fibers
Ground substance- glycoproteins, proteoglycans, H2O
Formative/Inductive functions of pulp
Dentinogenesis- primary, secondary, tertiary dentin (reparative/reactive)
Induces enamel formation and determines type/morphology of the tooth
Nutritive functions of pulp
Nourishes odontoblasts and dentin via pulpal blood supply
Sensory functions of pulp
Nerve fibers mediate pain (sensory/afferent)
Protective functions of pulp
Responds to irritations causing pain (mechanical, thermal, chemical, bacterial)
Pulpal reactions: tertiary dentin formation, inflammatory response—>
Acute= increased leukocytes (PMNs) Chronic= Increased lymphocytes & plasma cells
Composition of pulp
Cells Intercellular substance Tissue fluid (ECF) Blood vessels Lymphatic vessels Nerve tissue
1st Pulp zone/ Odontoblastic layer
Peripheral layer- one cell layer- lines pulp chamber/canals
Function: Formative (primary/secondary), protective (tertiary), sensory (pain)
2nd Pulp Zone- Cell Free Zone/Cell Free Layer of Weil
Fewer cells
During dentinogenesis, increased # of mesenchymal cells present
Function: sensory & nutritive
Contains: Nerve fibers, capillaries, collagen fibers & ground substance
3rd Pulp Zone- Cell Rich Zone
Increased cell content: fibroblasts, mesenchyme cells (migrate through cell free zone)
Decreased # of cells with age
Function: Formative, sensory, nutritive
Contains: Nerve fibrils & capillaries
Nerve and vascular plexus- Deep to cell rich zone
Raschkow’s plexus/parietal plexus of nerves
Vascular plexus of blood vessels (capillary network is more extensive during dentinogenesis)
4th Pulp Zone- Pulp Core
Bulk of pulp
Function: Formative, sensory, nutritive
Composition: All cells and intercellular substance
Vasculature of pulp
Maxillary Artery: Superior (max) and inferior (mand) alveolar arteries
Dental and alveolar arteries supply PDL & pulp. Pulpal BV branch off PDL vessels
Pulpal blood vessels
Coronal pulp: capillary loops form “vascular plexus”
Radicular pulp: Arterioles pass to subodontoblastic region
Arteriovenous Anastomoses
Drains the capillary beds in subodontoblastic region and exit by apex
Pericytes/Rouget cells
Myofibril in nature, contractile capabilities assist capillaries
Where do lymphatics run?
Same course as blood vessels (branch from PDL lymphatic vessels)
Which teeth do the submental nodes drain?
Mandibular incisors
Which teeth are drained by the superior deep cervical nodes?
Maxillary 3rd molars
Which teeth are drained by the submandibular nodes?
All maxillary and mandibular teeth besides the mandibular incisors and maxillary 3rd molars
Where does the maxillary division/superior alveolar nerve pass through?
Foramen rotundum
What area is targeted by the anterior superior alveolar block?
Incisors and canines
What area is targeted by the Middle superior alveolar block?
Premolars and MB root of the maxillary 1st molar
What area is targeted by the Posterior superior alveolar block?
DB root and pa;atal root of 1st molars, 2nd and 3rd molars
Where does the mandibular division/inferior alveolar nerve pass through?
Foramen Ovale
What area does the inferior alveolar block & lingual nerve block target?
All mandibular teeth and lingual gingiva
What are does the long buccal/buccal block target?
Posterior buccal gingiva
What are does the mental incisive block target?
Mandibular anteriors, premolars and associated buccal gingiva
Types of nerves
Sensory
Autonomic
Sensory- myelinated
Raschkow’s plexus- terminate between the odontoblastic cell bodies; may enter dentin tubules w/ odontoblastic process
Autonomic- unmyelinated
Regulate lumen of blood vessels
What are dystrophic calcifications?
Diffuse
Responsible for calcifications in root canals
Diffuse calcifications of collagen fibers surrounding nerve fibers & BV
Increase in size with age/ caries, restorations and/or trauma
Pulp stones/ Denticles
Calcified bodies, irregular to round shape
Vary in size, increased size with age
May lodge in or over root canal
Structural classifications of denticles
True denticle
False denticle
What are true denticles?
Rare- found only in RADICULAR pulp
Formed by odontoblasts- induced by HERS
Contain: dentin tubules, odontoblastic processes and odontoblasts
What are false denticles?
Concentric calcifications formed around foci of dead cells or collagen bundles
No odontoblasts, odontoblastic processes or dentin tubules
Location classifications of denticles
3 types- free, attached and interstitial
Found in coronal and radicular pulp (mostly radicular)
What are free denticles
Free floating in the pulp
WHat are attached denticles
On wall of pulp chambers (dentin) & protrude into pulp chamber
What are interstitial denticles
Completely embedded in the wall of the pulp chamber (dentin)
Mechanical pulpal irritations
Operative high speed drill
Thermal pulpal irritations
Heat produced by operative procedures
Hot and cold in general can affect irritated pulp
Chemical pulpal irritations
Restorative materials such as zinc phosphate or eugenol
-sweet or sour
Bacterial pulpal irritations
Caries invasion
Periodontal pocket, involving the apical region
Unnatural forces pulpal irritation
Stress fractures in enamel
High restorations
Changes in air pressure if pulp tissue is inflammed
What is focal reversible pulpitis
Earliest form of pulpitis- pulpal hyperemia
Localized to pulp of irritated dentin tubules
Cause: caries and defective restorations
Reversible if treated early
Tooth sensitive to cold and biting
What is acute pulpitis?
Caries that have reached the pulp Extensive acute inflammation PMN's very prominent; pus formation Heat and biting cause pain Notreversible Tx: RCT pulpectomy (permanent) pr pulpotomy (deciduous)
Comes at night, goes away in the morning
What is chronic pulpitis
Symptoms are milder Cause caries- dull ache Little response to thermal change Lymphocytes and plasma cells present Tx: RCT
What is chronic hyperplastic pulpitis
Deciduous teeth only
Chronic pulpal disease Caused by caries Pulp expands out of lesion and bleeds easily Heat causes pain Tx: pulpotomy
What are periapical abscesses?
Acute or chronic tissue breakdown at apical region
Cause: caries and/or trauma
Acute: PMN’s- very painful
Chronic: Lymphocytes & plasma cells- no pain
Radiolucent on radiographs
Periapical granuloma- caries or trauma
Localized granulation tissue due to infection
Tissue contained in a capsule, separates it from bone
Tx: RCT and possible apioectomy
Apical radiolucency
Periapical cysts
True cysts
Lined with epithelium- fluid filled
Develop from granulomas and associated with cell rests of Malassez (remnants of HERS)
Usually asymptomatic
Hallmark signs of cellulitis
Diffuse inflammation of the deep connective tissue Infection spreads from localized area Severe swelling of face and/or neck Area tissue become hard/rubbery Skin may appear red fever and malaise PMNs prominent
Serious cellulitis infection
May spread to floor of mouth and close the airway
May spread to cavernous sinus of the brain
Either may result in death
Internal root resorption
Starts within vital pulp tissue
Cause: unknown, trauma is suspected
Clastic cells (monocytes)- resorb root from inside canal
Tx: RCT- if diagnosed early
Dental pulp stem cells
Cells derived from embryonic mesenchyme
Location of dental pulp stem cells
Most abundant in primary teeth
Fewer in permanent teeth
Dental significance of dental pulp stem cells
Signals tissue formation and repair in the dentin-pulp complex
