Talk:Pulp (tooth)

Import from Endodontic therapy for use here if helpful

Pulp

The blood vessels and nervous tissue enter the tooth through the apical foramen and extend into the pulp horns (which can be larger and more superficial in younger patients). As blood vessels pass through the pulp proper- they branch to form an extensive vascular capillary network. This network supports and maintains the peripheral odontoblast layer. The pulp is always found at the centre of the tooth- parallel to its long axis.

In a single rooted tooth there is one apical foramen – although more are often found in multi-rooted teeth. The root canal extends to the narrowest point called the apical constriction. From here it extends into the apical foramen. Alongside the main RCS, there are also accessory/lateral canals which can branch off (especially in multi-rooted teeth). Furthermore, there can sometimes be multiple foramina (rather than just one apical foramen). These are known as apical deltas.

Constituents of the pulp

• Nerves
• Blood vessels
• Lymph vessels
• Odontoblasts
• Inflammatory cells
• Mechanoreceptors

With age the pulp becomes less vascular and more fibrous, this causes a decrease in healing capacity and so the pulp will become more fragile.

Pulp innervation

Innervation (both sensory and sympathetic) is supplied by the Trigeminal (V₂and V₃₎nerve. It branches into the plexus of Rashkow at the pulp-dentine border.  Almost all afferents within the pulpal tissue perceive pain (nociceptors):

Aδ fibres– innervates 90% of dentine. It is myelinated and responsible for sharp, fast pain. Their                               terminal afferents are in the periphery of the pulp.

C-fibres– account for 100% of the nociceptors within the pulp. They are unmyelinated and cause dull, burning pain. Their afferent terminals are in the pulp proper.

Dentine Pulp Complex

Types of Dentine:

1. Primary dentine:is the regular tubular dentine formed prior to tooth eruption and completion of the apical region of the tooth
2. Secondary dentine:is formed at a slower rate than primary dentine. It begins after completion of the crown and apex of the tooth and continues for the tooth’s lifetime. It is deposited all around the periphery of the tooth in an asymmetrical way – greater amounts are deposited on the roof and floor of the pulp chamber – which leads to pulpal recession in older individuals (can complicate endodontic treatment). The rate of deposition of secondary dentine appears to slow with age
3. Tertiary dentine:is irregular dentine formed in response to noxious stimuli – E.g. caries, attrition, cavity preparation etc. It is very quickly deposited in the focal area near the insult in a sparse and irregular tubular pattern. There are two types of tertiary dentine:

• Reactionary: where dentine is formed from a surviving pre-existing odontoblast. Typically caused by mild stimuli, which leads to up-regulation of the secretory activity of existing odontoblasts e.g. dentine hypersensitivity.
• Reparative: where newly differentiated odontoblast-like cells are formed (due to the death of the original odontoblasts) from a pulpal progenitor cells, which go on to secrete dentine matrix in an upregulated fashion.  It is typically formed due to a stronger stimulus e.g. someone with lots of caries will probably have reparative dentine. Reparative dentine is very irregular histologically compared to reactionary dentine. Where reactionary dentine is present, over time this may become reparative OR they may occur independently. Reparative dentinogenesis takes place at sites of pulp exposure because of the loss of the odontoblasts and the need for a dentine bridge to form.

Complete occlusion of the tubules can occur and such areas are described as ‘sclerotic’ dentine. This decreases the permeability of dentine.

Different types of tertiary dentine can be produced, including sclerotic and translucent.

1.    Sclerotic dentine is formed when the odontoblastic processes die and leave the tubules vacant– and the tubules become filled with a mineralised substance (whitlockite) similar to peritubular dentine.

2.    Translucent dentine is when the peritubular dentine completely occluding the tubules results in a translucent appearance as water is excluded.

Dead tracts occur if the primary odontoblasts are killed by an external stimulus or retract before peritubular dentine is laid down, leaving behind empty tubes. These tracts may be sealed at their ends by tertiary dentine.

Pulpal damage

Causes:

1. Physical
2. Bacterial
3. Chemical

Pulpal exposure

Causes of exposure:

1. Caries causes a slowly worsening inflammatory cell infiltration within the pulp
2. A traumatic or mechanicalpulp exposure is a sudden exposure in the absence of previous pulpal inflammation(we assume). Vital pulp treatment for an accidental exposure (traumatic or mechanical) through intact dentine has a higher success rate than through caries. 80% of direct pulp capped teeth (after carious pulp exposure) will die after 10 years.

When a vital pulp gets exposed we can give two main treatments. These treatments aim to: maintain pulpal health after exposure to the oral environment and re-establish as a painless, healthy pulpal condition in the long term(via dentine bridge formation).

1. Direct pulp cap
2. Pulpotomy

Routes of Pulpal Infection

Periodontal disease: microbes and their products can communicate between RCS and periodontium through: ·     Apical foramen – accessible due to bone loss and pocketing in advanced periodontics. Accessory/lateral canals – same as above ·     Exposed dentinal tubules
2. Trauma: Fractures and Cracks
3. Caries: PRP occurs most commonly as a sequel to an extensive carious lesion
4. Cracks: Cracks extending into the pulp chamber/ root canal system.
5. Operative procedures/ iatrogenic factors: Perforations, pulp exposures, marginal leakage, tooth preparations(crown preps) and scaling.

Diagnosis

Pulpal Diagnosis

1. Normal pulp
2. Reversibel pulpitis
3. Symptomatic irreversible pulpits
4. Asymptomatic irreversibel pulpitis
5. Pulp necrosis
6. Previously treated
7. Previously initiate therapy

Apical Diagnosis

1. Normal apical tissue
2. Symptomatic apical periodontitis
3. Asymptomatic apical periodontitis
4. Acute apical abscess
5. Chronic apical abscess
6. Condensing osteitis

When making an Endodontics diagnosis you have to write down two diagnoses, a plural diagnosis and an apical/periradicular diagnosis

The text above is copied from Endodontic therapy for use here if anything helpful.-Nizil (talk) 07:20, 15 January 2019 (UTC)

Dental Pulp Testing Subheading

I have relocated the information regarding dental pulp testing to the dental pulp test page to avoid the duplication of information. I have added in a very short outline of dental pulp testing on this page. Any issues with this please let me know Mhairimcg (talk) 15:41, 19 February 2019 (UTC)