Etiology and classification
The development of inflammation can be triggered by infection (predominantly bacterial) or physical and chemical agents. In the latter case, we speak of sterile pulpitis: traumatic, radiation, decompression, thermal (for example, during aggressive preparation), or toxic.
According to its localization, coronal, radicular, and total involvement are distinguished. From a clinical perspective, the most critical criterion is the response to therapy: the pathology can be reversible and irreversible. The transition to an irreversible course is usually caused by bacterial invasion of the tissue.
Acute forms of pulpitis
- Serous: Begins as a focal process (often near the bottom of the carious cavity), then may become diffuse. Often a sterile and reversible condition lasting only a few hours and ending in restitutio ad integrum (complete recovery). Without treatment, it progresses to purulent or chronic pulpitis.
- Focal purulent (pulp abscess): Develops with direct tissue infection.
- Diffuse purulent (pulp phlegmon): Involves both the coronal and radicular parts. Macroscopically, the tissue acquires a grayish tint with multiple small yellow foci. A paradoxical decrease in pain intensity in the later stages is characteristic, which is explained by the destruction of nerve endings by purulent exudate.
Chronic forms of pulpitis
Chronic inflammation can occur primarily (against the background of caries) or as an outcome of acute inflammation. It always leads to atrophy and loss of functionality.
- Granulating: Tissue is replaced by granulations, odontoblasts die, and dentin undergoes lacunar resorption with the formation of osteodentin. A special variant is a pulp polyp (chronic hypertrophic pulpitis) — a mushroom-like protrusion of granulation tissue from the carious cavity, characteristic of children and young adults.
- Fibrous: Formed during the maturation of granulations. The pulp cavity is filled with whitish, dense scar tissue. The process is accompanied by sclerosis, hyalinosis of the stroma, the formation of calcifications, pseudocysts, and colliquative necrosis of odontoblasts.
- Gangrenous (pulp gangrene): A conventionally chronic, rare form. It represents tissue necrosis with an exposed pulp cavity, resulting in the formation of greyish-black detritus, which subsequently condenses.
Reactive pulp changes
Any non-inflammatory processes in the neurovascular bundle of the tooth are called reactive. They are divided into three main categories:
- Alterative (damage): hydropic and fatty dystrophy of odontoblasts, mucoid and fibrinoid swelling of vessels (often in rheumatism), local or systemic hyalinosis. The extreme degree is tissue death: necrosis (with a closed cavity) or gangrene (with an open cavity).
- Dyscirculatory: local or general disturbances of blood and lymph circulation.
- Adaptive: reticular atrophy, pseudocyst formation, production of secondary (replacement) dentin. Calcifications play a crucial role — the deposition of petrificates (necro-, fibro-, and thrombocalcinosis) and the formation of denticles. The latter are dentin inclusions that can be intrapulpar (free), parietal (attached), or interstitial (embedded in the dentin layer).
Briefly: answers to topical questions
What complications can develop when the infection spreads beyond the pulp?
The main complication of infection spreading beyond the pulp is acute apical periodontitis. With its further progression, the following pathological conditions may develop:
- Acute purulent osteomyelitis — occurs when pus breaks through under the periosteum or into the jaw bone.
- Odontogenic sinusitis — develops when the inflammatory process is localized in the upper jaw.
- Subperiosteal abscess — forms when pus spreads through the bone marrow spaces to the periosteum.
- Submucosal abscess — forms upon the further breakthrough of pus under the mucous membrane.
Severe intracranial complications (purulent meningitis, brain abscess), purulent lesions of the neck and mediastinum, Ludwig's angina, and odontogenic sepsis are also possible.
What microorganisms form the basis of the microflora in infectious pulpitis?
The basis of the microflora in infectious pulpitis is formed by various bacteria, depending on the clinical and morphological form of inflammation. In general, the etiology of odontogenic infections is usually polymicrobial and represents associations of three or more species of microorganisms.
Specificity of pathogens in pulpitis:
- Serous form — streptococci, lactobacilli, and bacteroides form the basis of the microflora.
- Purulent form — hemolytic streptococcus and Staphylococcus aureus (S. aureus) predominate in the microflora.
Class and exam questions
What is a pulp polyp and in whom is it most commonly found?
This is a macroscopic manifestation of chronic hypertrophic (granulating) pulpitis, in which excessive granulation tissue protrudes mushroom-like from the destroyed dental crown. The pathology is most characteristic of children and young adults.
What is the difference between pulp necrosis and gangrene?
Both conditions mean tissue death, however, necrosis develops with a closed (intact or filled) pulp chamber, while gangrene develops with an exposed pulp cavity.
Why can pain subside over time in diffuse purulent pulpitis?
The accumulation of purulent exudate leads to the structural destruction of pulp nerve fibers, thereby disrupting the conduction of pain impulses.
Why is the lack of treatment dangerous in pulpitis?
A natural and most formidable complication of acute or exacerbated chronic pulpitis is the transition of the infection beyond the tooth root with the development of acute apical periodontitis.
What else to study on this topic
- Pathomorphological picture of acute serous pulpitis
- Microscopy of chronic granulating pulpitis (cellular composition)
- Morphogenesis and classification of denticles (high- and low-organized)
- Acute apical periodontitis: pathways of infection spread
- Histological signs of chronic fibrous pulpitis
Master the entire topic in the "Pathological Anatomy" course
This is a summary. The course covers everything tested in classes and exams.
- Complete study guide on "Pulpitis" and 4,414 more pages of the subject
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 153 video lessons on the subject
Other Topics in "Chapter 27. Diseases of the Dentofacial System and Oral Cavity"
Free video lessons: pathological anatomyShort lessons with study notes — no registration required.
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.