Dental Pulp Anatomy and Physiology

• The information is about pathological changes in the dental pulp and periodontium

Pulp Role

• Maintains and restores dentin health
• Provides sensitivity and circulation to teeth

Pulp Composition

• 75% water
• 25% organic and water-soluble inorganic substances
• Connective tissue that fills the root canal and pulp chamber

Pulp Matrix

• Contains Type III, I, and V collagen fibers
• Type III provides flexibility. Type I provides tensile strength. Type V provides characteristics to mesenchymal tissue
• Has a base of proteoglycan
• High water absorption and ion-binding capacity

Blood Supply

• Arteries and veins, specifically the alveolar superior and inferior branches supply blood
• Organized into artelioli and venules
• Capillary network toward the surface
• Maintains odontoblasts
• Regulates liquid level
• Lymphatic system drains excess interstitial fluid

Innervation

• Trigeminal nerve provides sensory fibers
• Cervical superior sensory fibers (GI)
• A-beta axon (small amount) is responsible for palpation and pressure sensation
• A-delta axon (2,000/tooth) leads to sharp, localized pain
• C axon (300/tooth) leads to dull, diffuse pain from thermal, mechanical, and chemical stimuli
• Fiber network forms under the odontoblast layer
• Some fibers reach the dentinal tubules

Causes of Pathological Changes

• Irritations and bacterial
• Mechanical irritations are typically due to dental preparation with insufficient cooling, high restorative work, orthodontic treatment, and improper scaling/curettage
• Chemical irritations include alcohol, hydrogen peroxide, pulp base issues, extended acid exposure, and inappropriate acid washing
• Bacterial causes can originate from the crown (caries), side canals (periapical space), or apex (retrograde)
• Inflammation can be endodontic, periodontal, or mixed

Markers of Pathological Changes

• Discomfort or pain
• A large hole in the tooth
• Extensive Caries
• Tooth discoloration
• Patient complaints are indicative of pathological changes

Development

• Irritation leads to tissue inflammation
• The process can be reversible or irreversible
• Symptoms vary with progression
• Inflammation can be acute or chronic
• Partial or complete necrosis can occur

Pathological Changes

• Reversible pulpitis
• Irreversible pulpitis
• Hyperplastic pulpitis (pulp polyp)
• Pulp necrosis
• Pulp calcification
• Internal Resorption

Reversible Pulpitis

• Caries, dental procedures (mechanical, chemical), cervical erosion, and high abrasion are etiological factors
• Sensitivity to cold, warm, salty, and sweet stimuli
• Pain is localized
• Pulp tissue damage is reversible
• Inflammation affects only the pulp tissue
• Exudate is draining (Starling hypothesis)

Sensitivity Test (Reversible pulpitis)

• Cold produces a stronger response than the test tooth
• Warm elicits no response
• Percussion elicits no response

Rtg (Reversible pulpitis)

• Does not give an X-ray image but may indicate caries depth

Treatment (Reversible pulpitis)

• Avoid irritating factors
• Deep caries supply and pulp capping if necessary

Irreversible Pulpitis

• Persistence of inflammation, caries reaching the pulp, and dental procedures/trauma are etiological factors
• Spontaneous, radiant, unlocalized pain, is noticeable when lying down
• Progress depends on the nature of inflammation or degree of necrosis

Acute Inflammation (Irreversible Pulpitis)

• Intense, excruciating, unbearable spontaneous pain
• Throbbing in the lying position due to vascular causes
• Cold stimulation intensifies the pain

Chronic Inflammation (Irreversible Pulpitis)

• Pain decreases and becomes throbbing and dull
• Inflammation turns into necrosis
• Cold sensitivity decreases
• Warm sensitivity increases with necrosis extent due to bacterial gas
• Open pulp chamber=pain is uncertain

Sensitivity Test (Irreversible Pulpitis)

• Pain persists after the stimulus terminates
• Cold elicits a positive response
• Warm response varies depending on the necrotic part
• Percussion elicits a positive response if it reaches the periodontitis

Rtg (Irreversible Pulpitis)

• No specific signs
• Advanced cases show widened periodontal ligaments

Treatment (Irreversible Pulpitis)

• Perform Root canal treatment
• Perform 1 session in serous/acute cases
• Perform two sessions in purulent/chronic cases, or if medicine is necessary

Hyperplastic Pulpitis

• A proliferative form of irreversible pulpitis
• More common in childhood because of larger pulp chambers
• May have no symptoms (exudate draining) or irreversible pulpitis symptoms
• Characterized by a livid red formula overgrown into the carious cavity; isolate from gingiva

Sensitivity Test (Hyperplastic Pulpitis)

• Response to stimuli is similar to an intact tooth

Rtg (Hyperplastic Pulpitis)

• No specific signs

Histology (Hyperplastic Pulpitis)

• Granulation tissue

Treatment (Hyperplastic Pulpitis)

• Pulpotomy if the apex is still open
• Root canal treatment if blood supply causes problems

Pulp Necrosis

• Irreversible pulpitis, trauma, and incorrect orthodontic treatment cause it
• The symptoms are often asymptomatic
• Warm causes pain in a closed cavity due to gas production by bacteria Pressure can cause pain

Process (Pulp Necrosis)

• Veins and lymph vessels compress
• Circulation stops
• Necrosis occurs

Clinical Appearance (Pulp Necrosis)

• Teeth discoloration

Sensitivity Test (Pulp Necrosis)

• Cold elicits no response
• Warm elicits a positive response
• Percussion elicits a positive response if it leads to the periapical space

Rtg (Pulp Necrosis)

• No specific signs

Treatment (Pulp Necrosis)

• Perform Root canal treatment (consider one or two sites depending on infection status)

Inside Resorption

• Inflammation of the pulp (pulpitis chronica or granulomatosa clausa)
• Immune cells in the granulation tissue and dentinoclasts break down the inside dentin

Symptom(Inside Resorption)

• An asymptomatic purple patch on the tooth crown

Process (Inside Resorption)

• Progressive

Clinical Appearance (Inside Resorption)

• Pink discoloration

Sensitivity Test (Pulp Necrosis)

• Response is similar to an intact tooth
• Teeth generally retain their vitality

Rtg (Inside Resorption)

• Radiolucens laesio inside the root

Treatment (Inside Resorption)

• Perform Root canal treatment rapidly
• Applying warm gutta-percha technique, using MTA

Pulp Calcification

• Causes are Advancing age and Persistent stimuli (e.g., caries) cause calcification
• Secondary dentin formation narrows the cavity system
• Occurs at the end of the root cement with foramen apical narrowing Reduction in blood flow due to arteriosclerotic changes
• Cellular elements decrease and collagen bundles are detected, leading to pulp fibrosis
• The number of blood vessels and nerves decreasing leads to decreased dentin permeability

Symptom (Pulp Calcification)

• Asymptomatic

Process (Pulp Calcification)

• Progressive

Clinical Appearance (Pulp Calcification)

• Crown may be discolored (yellowish)

Sensitivity Test (Pulp Calcification)

• No response to stimuli or reduced response

Rtg (Pulp Calcification)

• Pulp chamber and root canal narrowing/obstruction
• Pulp stones
• Calcification metamorphosis

Treatment (Pulp Calcification)

• Root canal treatment if necessary

Differential Diagnosis

• Differentiate between Dentin sensitivity, Irreversible pulpitis, Sinusitis, and Unlocalizable pain:
• Pain in dentin sensitivity is similar to reversible pulpitis, caused by hydrostatic pressure differences irritating nerve endings
• Irreversible pulpitis requires allocation from periapical inflammation
• Axial percussion sensitivity indicates apical periodontitis
• Fistula indicates a periapical abscess
• Apical processes generally have X-ray findings

Thermal and Electrical Pain (Differential Diagnosis)

• Thermal and electrical pain stimuli may not elicit a response in the tooth when suffering from sinusitis
• Sinusitis=pain when driving forward and pressure causing pain in the front wall of the maxilla
• Unlocalizable pain requires separation from jaw pain, neuralgic pain, otitis media, osteomyelitis, and parotid inflammation

Acute Apical Periodontitis

• Etiology is Pulp necrosis and Inflammation reaching the periapical tissue
• Can result from endodontic or paradontal process

Symptoms (Acute Apical Periodontitis)

• Intense pain when biting or touching the affected tooth
• Inflammation leads to edema fluid→pressure on the nerve Elongation (feeling) of the tooth

Process (Acute Apical Periodontitis)

• Dependant on virulence and exposure time
• Stronger infection than body defenses leads to intense acute inflammation
• Increased edema fluid leads to pain
• Untreated cases progress to abscess

Sensitivity Test (Acute Apical Periodontitis)

• Cold elicits no response
• Warm elicits a positive response
• Palpation reveals tooth mobility
• Percussion causes intense pain

Rgt (Acute Apical Periodontitis)

• A negative result can occur
• Root membrane gap widening may appear after 10-12 days
• Positive results appear after chronic inflammation with resorption bone defense

Treatment (Acute Apical Periodontitis)

• Reduce occlusion
• Perform Root canal treatment (open/close) in two sites

Chronic Apical Periodontitis

• Permanent presence of moderate virulence bacteria and Untreated pulp necrosis
• Can result from Incomplete root canal treatment (dead space)
• Periodontitis apicalis acuta

Symptom (Chronic Apical Periodontitis)

• Discomfort when biting

Process (Chronic Apical Periodontitis)

• Chronic inflammation leads to reabsorption of lamina dura, becoming asymptomatic or with mild discomfort

Sensitivity Test (Chronic Apical Periodontitis)

• Cold or electrical stimuli elicit no response
• Warm elicits a positive response, especially in closed teeth
• Palpation and percussion can cause sensitivity

Rtg (Chronic Apical Periodontitis)

• Destruction of periapical tissues

Histology (Chronic Apical Periodontitis)

• Granulomatic tissue + macrophag, histiocyta plasma cell
• Cyst: eosinophil fluid multilayered epithelium, connective tissue,, granulomatic cells

Treatment (Chronic Apical Periodontitis)

• Root canal treatment (one or two sites)

Acute Apical Abscess

• Occurs when a chronic process flares up
• The body reacts severely to irritative factors from the necrotized pulp
• Pain and systemic symptoms such as fever, malaise, and leukocytosis can be observed

Process (Acute Apical Abscess)

• Inflammation leads to abscess formation, which melts or spreads diffusely in the periapical space

Sensitivity Test (Acute Apical Abscess)

• No response to heat or electrical stimuli
• Upon palpation, the affected tooth may be loose and have swelling
• Percussion is forbidden due to intense pain

Rtg (Abscessus Apicalis Acuta)

• Thickened, widened root membrane gap seen
• May show a picture typical of chronic apical periodontitis later

Histology (Abscessus Apicalis Acuta)

• Abscess contains PMN leukocytes
• Granulomatous tissue
• Purulent exudate

Treatment (Abscessus Apicalis Acuta)

• Perform Drainage
• Root canal treatment (closing in two sessions)
• Administer Antibiotics
• Refer to Oral surgeon

Chronic Apical Abscess

• Caused by Abscess formation after pulp necrosis or periodontitis apicalis chronica
• Results in Fistula→drainage→no pain

Treatment (Chronic Apical Abscess)

• Perform Root canal treatment at one site

Condensing Osteitis Etiology

• Inflammation spreads into the root membrane gap
• Pulp necrosis or irreversible pulpitis
• Persistent minor infection and mild toxin effect result in a local defense mechanism that reduces inflammation

Symptom (Condensing Osteitis)

• Asymptomatic, with occasional discomfort

Process (Condensing Osteitis)

• Inflammation→increased osteoblast activity→hyperossification

Sensitivity Test (Condensing Osteitis)

• Percussion elicits no response

Rtg(Condensing Osteitis)

• Shows irregular, diffuse, concentric radiopaque bone around the root apex
• Often develops around the roots of lower molar teeth

Histology (Condensing Osteitis)

• Irregular bone structure

Treatment (Condensing Osteitis)

• Root canal treatment

Differential Diagnosis, Anatomical formulas:

• Canalis mandibulae
• Foramen mentale
• Sinus maxillaris
• Foramen incisivum

Benign Lesions (Differential Diagnosis)

• Not originating from the periodontium:
• Cementoma
• Monostaticus fibroticus
• Dysplasia
• Traumatic bone cyst
• Ameloblastoma
• Central hemangioma

Malignant Lesions (Differential Diagnosis)

• Not originating from the dental pulp:
• Chondrosarcoma
• Myeloma