What is dental pulp?
Although the teeth are particularly hard and resistant, below the outer layers (enamel and dentine) we find a rather soft tissue, called pulp, which is essential for maintaining the vitality of each dental element.
The dental pulp is a soft, non-calcified tissue, indispensable for ensuring adequate supply of blood, oxygen and nutrients, al dente. It is enclosed in the pulp chamber, cavity inside the crown (see image to the side), and in the root canals, located in or in the roots of the tooth. Two sections of the dental pulp are therefore distinguished:
- Chamber pulp: portion of pulp contained within the dental crown
- Root pulp: part of the pulp that extends along the root canal. The nerve and vascular bundles contained within it access through the radicular foramen.
Glossary
Dental crown: dental section that protrudes from the alveolus
Alveolus: bone cavity in which the roots of the teeth are housed
Root canal: canaliculus within the root, in which nerve fibers and blood vessels flow
Root foramen: point from which nerves and blood vessels access the tooth
Functions
A tooth could not live without its dental pulp, this being an indispensable tissue for every dental element. Let's see below what the main functions of the pulp are:
- Dentin production (dentinogenesis): the odontoblasts located on the pulpo-dentinal junction are the cells used for this function.
- Nourishing (trophic) function: the dental pulp nourishes the avascular dentin allowing the diffusion of the nutrients coming from the rich blood supply
- Protective function exerted by dentin, in turn formed by the odontoblasts
- Sensory function: being highly receptive to changes in temperature, traumas and pressure variations, the dental pulp gives sensitivity to the tooth through the nervous bundles enclosed within it; some of these penetrate with unmyelinated fibers up to the dentin along the radical channels and giving reason for the marked pain sensitivity of this area (see sensitive teeth)
- The pulp ensures an adequate vascular supply to the dental element through venules and arterioles
cells
The dental pulp consists of mucous connective tissue (a type of loose connective tissue) made up of 25% organic material and 75% water; dentin is instead composed of 20% organic material and 80% hydroxyapatite (inorganic); the latter reaches 95% in the enamel, the very hard and translucent fabric that covers and protects the tooth.
The dental pulp is rich in nerve fibers, blood vessels and cells that synthesize dentin. More precisely, the dental pulp can be divided into three layers, each of which is distinguished by a particular cellular composition; from the center to the periphery we find:
- Zone of "Rinaggio" (more internal), containing fibroblasts and undifferentiated mesenchymal cells. The fibroblasts act as a support for all the other components of the dental pulp; they, synthesize collagen and fundamental substance, and guarantee the transport of nutrients from cells to blood and vice versa.
- Zone of "Weil", consisting of a network of nerve fibers (Rashkoff's nerve plexus) and capillaries. The nerve bundles enter the dental pulp starting from the apical foramen; as anticipated, from the nervous plexus of Rashkoff branch off amyelinic nerve fibers through the layer of odontoblasts to the dentin canaliculi
- Outside area containing odontoblasts. The odontoblastic layer consists of highly differentiated cells responsible for the production and secretion of dentinal components. These specific cells take on a very particular disposition: while in the coronal section they are arranged in a palisade, in the radical portion the odontoblasts are arranged in rows of cubic cells that gradually flatten as they approach the root apex.
Related diseases
We have seen that the dental pulp gives sensitivity to the tooth thanks to the fibers that innervate it.
That said, it is understandable that toothache and dentinal hypersensitivity are the two main disorders triggered by a generic inflammation of the pulp tissues.
A strong trauma, a severe dental chipping or a generic tooth infection can seriously compromise the function and structure of the dental element, causing very intense pain and leading to necrosis or gangrene of the dental pulp. An insult of external origin to the dental pulp - whether this is an infection or a trauma - can give rise to a series of disorders such as to irreversibly damage the tooth.
The most common diseases related to dental pulp infection include:
- Pulpitis : general inflammation of the pulp tissues, a typical consequence of caries not adequately treated. Pulpitis cannot be treated by simple dental filling: in such situations, devitalization is the treatment of choice. Only in extremely severe cases, tooth extraction is required.
- Dental abscess : accumulation of bacteria, white blood cells, plasma and cellular debris (pus) in the tissues surrounding a tooth. When the abscess involves the dental pulp, the patient perceives a piercing toothache and is difficult to placate by the classic analgesic drugs. If diagnosed early, before the infection is pushed into the pulp or alveolus, the abscess can be treated with an antibiotic treatment and / or with the drainage of the purulent material accumulated inside it.
- Dental radicular cyst: typical complication of necrosis of the dental pulp, in turn induced by trauma, deep caries or pulpits. Apicectomy is the first choice treatment for dental cysts.
- Dental granuloma : chronic inflammation, generally asymptomatic, of the root apex and adjacent tissues. When not treated in time by devitalization or apicectomy, dental granuloma can spill over into the dental pulp, causing pulpits and necrosis of the dental pulp.
