Pediatric Dentistry

Pediatric Dentistry “Anatomy and Physiology of the pulp temporary and permanent teeth in children. Etiology and pathogenesis of pulpitis. Classification. The clinic, diagnosis and differential diagnosis ofpulpitis in children.” Lecturer: Dr. KatrinDuda

Pulp From many perspectives, dental health is directlyrelated to the health of a unique tissue-that is,dental pulp. However, the study of dental pulp isnot restricted to this tissue alone, but extends toits interactions with many other tissues in healthand disease. For example, since dentin and pulpareanatomically and functionally integrated, they are often referred to as the pulpodentincomplex.

Pulp The pulp also interacts with other tissues such as the periodontium and even the central nervous system. Indeed, the interrelationship between dental pulp and other tissues is a major theme in the field of dentistry, in pulp biology research, and of course, in this textbook. It also serves as a rationale for the specialty of endodontics.

Pulp According to one recent endodontics text, the purpose of endodontic treatment is not to pre-serve the pulp but to eliminate it, so as to remove those factors found in necrotic and infected pulp that stimulate apical periodon-titis. 2 Thus, the biologic rationale for nonsurgical endodontic treatment is to manage the apical periodontitis that results from the functional relationship between infected dental pulp and apical tissue.

Pulp

Pulp • The dental pulp is the part in the center of a tooth made up of living connective tissue and cells called odontoblast. The dental pulp is a part of the dentin–pulp complex (endodontium). The vitality of the dentin-pulp complex, both during health and after injury, depends on pulp cell activity and the signaling processes that regulate the cell’s behavior.

Anatomy Pulp • Each person can have a total of up to 52 pulp organs, 32 in the permanent and 20 in the primary teeth. The total volumes of all the permanent teeth organs is 0.38cc and the mean volume of a single adult human pulp is 0.02cc. Maxillary central incisor has shovel shaped coronal pulp with three short horns on the coronal roof and triangular in cross section. Canine has the longest pulp with elliptical cross section.

Anatomy Pulp The large mass of pulp is contained within the pulp chamber of the tooth. The shape of each pulp chamber corresponds directly to the overall shape of the tooth, and thus is individualized for every tooth; the pulp tissue in the pulp chamber has two main divisions: coronal pulp and radicular pulp. Crowns of the teeth contain coronal pulp. The coronal pulp has six surfaces: the occlusal, the mesial, the distel distal, the buccal, the lingual and the floor. Because of continuous deposition of dentin, the pulp becomes smaller with age. This is not uniform throughout the coronal pulp but progresses faster on the floor than on the roof or side walls.

Anatomy Pulp • Radicular pulp is that pulp extending from the cervical region of the crown to the root apex. They are not always straight but vary in shape, size and number. The radicular portion is continuous with the periapical tissues through.

Anatomy Pulp • Apical foraen is the opening of the radicular pulp into the periapical connective tissue. The average size is 0.3 to 0.4 mm in diameter. There can be two or more foramina separated by a portion of dentin and cementum by cementum only. If more than one foramen is present on each root, the largest one is designated as the apical foramen and the rest are considered accessory foramina. Most infections spread through the apical foramen from the pulp to periapical tissue.

Anatomy Pulp Accessory canals are pathways from the radicular pulp, extending laterally through the dentin to the periodontal tissue seen especially in the apical third of the root. Accessory canals are also called lateral canals, because they are usually located on the lateral surface of the roots of the teeth. Anatomy Pulp

Development • The pulp has a background similar to that of dentin, because both are derived from the dental papilla of the tooth germ. During odontogenesis, when the dentin forms around the dental papilla, the innermost tissue is considered pulp.

Structure of pulp The central region of the coronal and radicular pulp contains large nerve trunks and blood vessels. Has four layers : • Pulpal core, which is in the center of the pulp chamber with many cells and an extensive vascular supply; except for its location, it is very similar to the cell-rich zone. • Cell rich zone; which contains fibroblasts and undifferentiated mesenchymal cells. • Cell free zone which is rich in both capillaries and nerve networks. • Odontoblastic layer; outermost layer which contains odontoblasts and lies next to the predentin and mature dentin.

Functions The primary function of the dental pulp is to form dentin. Other functions include: • Nutritive: the pulp keeps the organic components of the surrounding mineralized tissue supplied with moisture and nutrients; • Sensory: extremes in temperature, pressure, or trauma to the dentin or pulp are perceived as pain; • Protective: the formation of reparative or secondary dentin; • Formative: cells of the pulp produce dentin which surrounds and protects the pulpal tissue.

Complications • Pulp acts as a security and alarm system for a tooth. Slight decay in tooth structure not extending to the dentin may not alarm the pulp but as the dentin gets exposed, either due to dental caries or trauma, sensitivity starts. The dentinal tubules pass the stimulus to odontoblastic layer of the pulp which in turns triggers the response. This mainly responds to cold. At this stage simple restorations can be performed for treatment.

Complications • As the decay progresses near the pulp the response also magnifies and sensation to a hot diet as well as cold gets louder. At this stage indirect pulp capping might work for treatment but at times it is impossible to clinically diagnose the extent of decay, pulpitis may elicit at this stage. Carious dentin by dental decay progressing to pulp may get fractured during mastication (chewing food) causing direct trauma to the pulp hence eliciting pulpitis.

Complications • The inflammation of the pulp is known as pulpitis. Pulpitis can be extremely painful and in serious cases calls for root canal therapy or endodontic therapy.Traumatized pulp starts an inflammatory response but due to the hard and closed surroundings of the pulp pressure builds inside the pulp chamber compressing the nerve fibres and eliciting extreme pain (acute pulpitis). At this stage the death of the pulp starts which eventually progresses to periapical abscess formation (chronic pulpitis).

Complications • The pulp horns recede with age. Also with increased age, the pulp undergoes a decrease in intercellular substance, water, and cells as it fills with an increased amount of collagen fibers.This decrease in cells is especially evident in the reduced number of undifferentiated mesenchymal cells. Thus, the pulp becomes more fibrotic with increased age, leading to a reduction in the regenerative capacity of the pulp due its loss of these cells.

Complications • Also, the overall pulp cavity may be smaller by the addition of secondary or tertiary dentin, thus causing pulp recession. The lack of sensitivity associated with older teeth is due to receded pulp horns, pulp fibrosis, addition of dentin, or possibly all these age-related changes; many times restorative treatment can be performed without local anesthesia on older dentitions.

Pulpitis • Pulpitis is inflammation of dental pulp tissue. The pulp contains the blood vessels the nerves and connective tissue inside a tooth and provides the tooth’s blood and nutrients. Pulpitis is mainly caused by bacteria infection which itself is a secondary development of caries (tooth decay). It manifests itself in the form of a thoothach.

Causes • Pulpitis may be caused by a dental caries that penetrate through the enamel and dentin to reach the pulp, or it may be a result of trauma, such as thermal insult from repeated dental procedures. Inflammation is commonly associated with a bacterial infection but can also be due to other insults such as repetitive trauma or in rare cases periodontitis. In the case of penetrating decay, the pulp chamber is no longer sealed off from the environment of the oral cavity.

Causes When the pulp becomes inflamed, pressure begins to build up in the pulp cavity, exerting pressure on the nerve of the tooth and the surrounding tissues. Pressure from inflammation can cause mild to extreme pain, depending upon the severity of the inflammation and the body's response. Unlike other parts of the body where pressure can dissipate through the surrounding soft tissues, the pulp cavity is very different. It is surrounded by dentin, a hard tissue that does not allow for pressure dissipation, so increased blood flow, a hallmark of inflammation, will cause pain.

Causes • When the pulp becomes inflamed, pressure begins to build up in the pulp cavity, exerting pressure on the nerve of the tooth and the surrounding tissues. Pressure from inflammation can cause mild to extreme pain, depending upon the severity of the inflammation and the body's response. Unlike other parts of the body where pressure can dissipate through the surrounding soft tissues, the pulp cavity is very different. It is surrounded by dentin, a hard tissue that does not allow for pressure dissipation, so increased blood flow, a hallmark of inflammation, will cause pain.

Causes Pulpitis • Pulpitis can often create so much pressure on the tooth nerve that the individual will have trouble locating the source of the pain, confusing it with neighboring teeth, called referred pain. The pulp cavity inherently provides the body with an immune system response challenge, which makes it very difficult for a bacterial infection to be eliminated.

Causes Pulpitis • If the teeth are denervated, this can lead to irreversible pulpitis, depending on the area, rate of infection, and length of injury. This is why people who have lost their dental innervation have a reduced healing ability and increased rate of tooth injury. Thus, as people age, their gradual loss of innervation leads to pulpitis.

Diagnosis and classification of pulpal diseases • As in all infections, the body answers with increased circulation (hyperaemia): the supplying blood vessels expand. Hyperaemia can transform into an acute or chronic pulpitis. A tooth with acute pulpitis is extremely sensitive to temperature. Cool air is sufficient to trigger the pain. In pulpitis acuta serosa, extended capillary vessels cause the excretion of granulocytes and serum. Activated enzymes, causing the breakdown of proteins, create pus, leading to severe pain in pulpitis acuta purulenta.

Chronic pulpitis • Chronic pulpitis on the other hand is often completely without symptoms. It is usually caused by caries. White blood cells (leucocytes) accumulate in the pulpa to combat inflammation. The bacteria cause the blood vessels of the pulpa to become permeable to serum (pulpitis serosa) and the number of infection combating cells increases (e.g., lymphocytes). Bacteria aggravate the infection. Pus-forming granulocytes supervene and the pain intensifies.

Acute pulpitis • In reversible, acute pulpitis, the tooth reacts to sweetness, cold and heat. The pain lasts for a short while only. The sensitivity test is positive. If caries can be removed without opening the pulpa, the tooth loses its symptoms. The pulpa can be kept vital. This acute form of pulpitis is therefore reversible.

Acute pulpitis • In irreversible pulpitis, which may be acute or chronic, the tooth is permanently painful. The dentin is frequently destroyed up to the pulpal cavity and cariously altered. Pain continues even after caries removal and medicamentous filling. The tooth's sensitivity to touch and biting is joined by decreasing or lacking reaction to a sensitivity test. The damaged pulpa cannot be reversed to its original healthy state, it is irreversible.

Diagnosis and classification of pulpal diseases • Vitality loss of the tooth marrow leads to pulpal necrosis which initially shows no symptoms. This may occur through a bacterial infection such as gangrene or after trauma without the participation of bacteria. If infection occurs in the jaw bone via the foramen apicale, it results in acute or chronic apical parodontitis. Diagnosis is confirmed with a negative sensitivity test. Therapy consists of trepanation with subsequent root canal preparation and filling.

Root canal treatment Root canal treatment can be divided into: • Removal of pulpal tissue • Determination of root canal length • Preparation of root canals • Filling of root canals

Root canal treatment • The determination of the root canal length specifies the operational length of the root canal instruments by displaying the length to the foramen apicale. A decisive factor for the correct filling of the canals is its length, previously determined by X-ray. The X-ray displays how far the instrument is away from the root tip and which length the instruments in the canal may have. Determination of canal length can also be performed electrically, whereby a probe is inserted into the canal and the end of the root canals is indicated by a measurement device.

Root canal treatment • Root canal preparation serves to prepare the root canal for root filling. The canals are extended and planed with flexible, mechanically or manually driven drills and files, which adjust even to arched or bent roots. Canal preparation is also possible with ultrasound. • Canal preparation should be performed up to the foramen apicale.

Root canal treatment

Root canal treatment • Unintended lateral penetration of the root is called “via falsa” (the “wrong way” in Latin). The objective of root canal filling is to fill the prepared root canal with special, bacteria-proof paste and matching gutta-percha tips and thus ensure sustainable treatment success. Root canal filling is performed with endogenous substances, which should be tissue-compatible, hardening, fluid, dimensionally stable, parietal, bacteria-proof, non-resorbable and visible on X-ray.

Root canal treatment • In thermoplastic root canal filling, heated and formable gutta-percha is injected into the prepared root canal or inserted as gutta-percha pins. The insertion of several gutta-percha pins with hardening pastes is preferred. While the orthograde root canal filling is normally positioned from the crown, the retrograde root canal filling is performed at the tip of the root (e.g., in root tip resection).

Thank you for attention

Pediatric Dentistry