bubble_chart Overview

Pulp diseases refer to conditions affecting the dental pulp, including pulpitis, pulp necrosis, and pulp degeneration. Since the pulp tissue is enclosed within the hard dental structures and only connects to the outside through the apical foramen and accessory canals, acute pulp inflammation causes vascular congestion and exudate accumulation, leading to increased pressure within the pulp chamber. This compresses the nerves and, combined with the irritation from inflammatory exudates, results in severe pain.

bubble_chart Etiology

1. Microbial Infection

Bacteria are the most important pathogenic factor in pulp diseases, primarily consisting of facultative anaerobes and obligate anaerobic bacilli, such as streptococci, actinomycetes, and lactobacilli.

The routes of bacterial infection include:

(1) Infection through tooth defects, such as deep caries, dental trauma, or severe tooth wear (grade III), where bacteria and toxins invade the pulp through dentinal tubules or exposed pulp.

(2) Infection via periodontal pathways, where bacteria and toxins enter the pulp through the periodontal pocket, apical foramen, or lateral accessory canals.

(3) Hematogenous infection, where bacteria and toxins invade the pulp through the bloodstream, which is extremely rare but not impossible.

2. Chemical Stimulation

(1) Drug irritation

Medications used for cavity disinfection, such as phenols, can irritate the pulp.

(2) Filling material irritation

Directly lining deep cavities with zinc phosphate cement or filling with composite resin may irritate the pulp.

3. Physical Stimulation

(1) Temperature irritation

When preparing cavities, water spray must be used with air turbines to cool the tooth; otherwise, it may cause pulp hyperemia, hemorrhage, and inflammation.

(2) Electrical irritation

If two different metal restorations come into contact in the oral cavity, a potential difference can be generated through saliva, causing some irritation to the pulp.

(3) Effects of气压 changes

During high-altitude flights or deep-sea diving,气压 changes can trigger acute pulp lesions.

(4) Trauma

Conditions such as diabetes can lead to pulp degeneration, and tumors may also affect the pulp. Hematogenous infections causing pulp diseases are extremely rare.

bubble_chart Clinical Manifestations

1. Acute pulpitis

is mostly caused by trauma, characterized by severe spontaneous pain with the following features:

① The pain often occurs suddenly, intermittent in the early stage, typically lasting for several minutes, followed by a few hours of remission, during which the patient can still identify the affected tooth. As the condition progresses, the duration of the attack stage prolongs, the remission period shortens, and the pain gradually becomes continuous and severe, radiating along the distribution areas of the three branches of the ipsilateral nerve (e.g., upper teeth radiating to the neck, preauricular, and zygomatic regions; lower teeth radiating to the subauricular, retroauricular, and mandibular regions). The patient often cannot pinpoint the exact location of the affected tooth.

② The pain is usually more severe at night, especially when lying down.

③ In the early stage, both cold and heat stimuli can trigger or exacerbate the pain, with cold stimuli being more pronounced. In the late stage [third stage] or when suppuration occurs, heat stimuli cause pain, while cold stimuli may temporarily alleviate the pain. Patients in the late stage [third stage] often hold cold water in their mouths or inhale cold air to relieve the pain, which can be diagnostically helpful.

④ During examination, the affected tooth often shows exposed pulp, with obvious tenderness upon probing.

2. Chronic pulpitis

Since conditions like dental caries are mostly chronic sexually transmitted diseases, they exert long-term, persistent irritation on the pulp, leading to chronic inflammatory processes. During the progression of chronic pulpitis, if polymorphonuclear leukocytes increase, the release of lysosomal enzymes also rises, exacerbating the inflammation and resulting in acute clinical symptoms.

Chronic dental injury, periodontal disease, and chemical irritation of dentin can all induce chronic inflammatory processes in the pulp.

Clinically, chronic pulpitis is classified into three types: chronic closed pulpitis, chronic open pulpitis, and chronic hyperplastic pulpitis. Chronic open pulpitis is also called chronic ulcerative pulpitis. Chronic hyperplastic pulpitis is also known as pulp polyp.

Diagnostic criteria for chronic pulpitis: ① Long-term irritative pain, with X-rays showing widened periapical membrane space and damaged hard plate; ② History of spontaneous pain; ③ Probing reveals exposed pulp, bleeding, and severe pain; ④ Presence of deep caries, deep periodontal pockets, or severe chronic dental injury.

Note: Differentiate between pulp polyp and gingival papilla hyperplasia growing into the occlusal cavity of adjacent teeth, as well as polyps growing through the perforated pulp floor. Otherwise, the consequences can be severe.

bubble_chart Diagnosis

1. Inquire about the nature of the toothache, frequency of episodes, and duration of each pain, its relation to hot/cold stimuli and chewing, whether the pain can be accurately localized or radiates, any connection to body position, and if it affects sleep. Ask whether the affected tooth, adjacent teeth, or nearby organs have recently been injured or treated. Determine if there is a history of toothache and whether it resembles the current pain.

2. Examine the affected tooth for cavities, their location and depth, whether the pulp is exposed, presence of probing pain or percussion pain, and responses to hot/cold stimuli and electric pulp testing. If no cavities are found, check for other hard tissue lesions, periodontal pockets, or tooth mobility. X-rays, cavity preparation, or pulp exposure tests may be necessary if needed. If no obvious lesions are detected, examine other teeth or adjacent organs for abnormalities and differentiate from trigeminal neuralgia.

3. Pulp diseases can be classified into:

① Chronic pulpitis – History of spontaneous pain or prolonged provoked pain. Examination reveals cavities near or exposing the pulp, probing pain, or pulp polyp, periodontal disease, or other hard tissue lesions. The pulp remains vital, and X-rays may show normal periapical conditions, widened periodontal ligament space, damaged lamina dura, or alveolar bone/root furcation resorption.

② Acute exacerbation of chronic pulpitis – Symptoms of chronic pulpitis with recent severe spontaneous pain, inability to localize or radiating pain, and pain triggered or worsened by hot/cold stimuli.

③ Acute pulpitis – Often occurs after accidental trauma or recent dental procedures, presenting with hot/cold-induced pain and spontaneous pain.

④ Partial pulp necrosis – Exhibits pulpitis symptoms with exposed pulp. Upon opening, the coronal pulp is non-vital, but the root pulp remains vital.

⑤ Total pulp necrosis – May have a history of pulpitis or trauma, with exposed pulp but no probing pain. Alternatively, periodontal lesions may be present, vitality tests show no response, and pulp examination confirms non-vitality. {|107|}

bubble_chart Treatment Measures

1. Principles of Treatment Pulp therapy is applicable for the treatment of pulp diseases and periapical diseases. The principles are as follows: acute symptoms should be treated first to relieve severe pain; efforts should be made to preserve the pulp partially or completely; if the pulp cannot be preserved, the tooth should be retained. Different treatment methods are adopted based on the nature of the lesion, age, and health condition. Teeth that are non-restorable, incurable, or even harmful to the body may be extracted.

2. Treatment Methods

(1) Emergency Treatment: ① Pulp opening and drainage. In cases of acute pulpitis or periapical inflammation, the pulp cavity must be opened. For the latter, the root canal should also be cleaned, and the apical foramen opened to reduce internal pressure, drain inflammatory exudate, and relieve acute pain. ② Incision and drainage. For subperiosteal or submucosal abscesses, a local incision should be made, and a drainage strip placed. ③ Analgesic medication. Commonly, medicated cotton soaked with clove oil or eugenol is placed in the carious cavity, or analgesic powder is placed in the nostril. Oral analgesics may also be administered.

(2) Indirect Pulp Capping: Indicated for deep caries near the pulp or mild pulp lesions without pulp exposure. After cavity preparation and removal of carious tissue, the cavity is disinfected, and a pulp-capping agent is applied to the cavity floor. A zinc phosphate cement base is placed, followed by amalgam or composite resin filling. Common pulp-capping agents include calcium hydroxide and its preparations, as well as zinc oxide eugenol cement.

(3) Direct Pulp Capping: Indicated for accidental pulp exposure due to trauma or cavity preparation, with an exposure diameter of less than 1mm. Moisture control is essential. After cavity preparation and local disinfection, a pulp-capping agent is applied to the exposure site, followed by base placement and cavity filling. Follow-up observation is necessary to check pulp vitality.

(4) Pulpotomy: Indicated for mild pulp lesions where the entire pulp cannot be preserved, particularly suitable for young permanent teeth with incomplete root development. Under local anesthesia, caries are removed, and the cavity is prepared, cleaned, and disinfected. The pulp chamber is opened, and the coronal pulp is excised. After thorough hemostasis, calcium hydroxide preparation is placed at the root canal orifice, followed by base placement and filling. If spontaneous pain occurs postoperatively, mummification or pulpectomy may be considered.

(5) Pulp Mummification: Indicated for pulp lesions with partial necrosis of the coronal pulp, cases requiring pulp chamber retention, or teeth needing pulp devitalization, mainly for posterior teeth. First visit for devitalization: The cavity is enlarged, and caries are removed. A devitalizing agent is placed at the exposure site, and the cavity is sealed with zinc oxide eugenol cement to prevent leakage and chemical burns to periodontal tissues (avoid pressure during placement). Second visit for pulpotomy and filling: The devitalizing agent is removed, and all carious tissue is excised. The coronal pulp is removed. The pulp chamber is dried with an alcohol-soaked cotton ball or a formocresol cotton ball is placed at the root canal orifice for 1 minute. A mummifying agent (about 1mm thick) is then placed at the root canal orifice, followed by base placement and filling. Occlusion should be adjusted to prevent tooth fracture. If symptoms persist postoperatively, pulpectomy or root canal therapy may be performed.

One-visit Pulp Mummification: Indications are the same as for conventional mummification but completed in one visit. Under local anesthesia or rapid devitalization (e.g., toad venom), the coronal pulp is removed, and a mummifying agent is applied, followed by base placement and filling. The mummifying agent should contain an increased dose of analgesics and paraformaldehyde to reduce postoperative pain. Hemostasis must be achieved before applying the mummifying agent.

(6) Modified Pulp Mummification for Deciduous Teeth: Indicated for deciduous teeth with pulp necrosis or periapical inflammation. ① Caries are removed, and the cavity is prepared. The necrotic coronal pulp is excised. A formocresol cotton ball is placed in the pulp chamber and sealed with zinc oxide eugenol cement for 3–7 days. ② If no swelling or pain occurs after sealing, the dressing is removed, and a mummifying agent is placed at the root canal orifice, followed by base placement and filling.

bubble_chart Differentiation

1. Interdental Papillitis Caused by food impaction leading to papillitis. There is spontaneous pain characterized by persistent distending pain and sensitivity to hot and cold stimuli. Examination reveals congested and edematous interdental papillae, with obvious localized gingival tenderness. Food impaction in the interdental space is often visible.

2. Trigeminal Neuralgia The nature of trigeminal neuralgia is sharp pain, sudden onset, and severe tearing-like pain with referred pain along the distribution of the trigeminal nerve. The key difference from acute pulpitis is that trigeminal neuralgia rarely occurs at night and is often triggered by activities like washing the face or talking. Each episode is brief, lasting from a few seconds to 1-2 minutes, rarely exceeding 5 minutes. Hot and cold stimuli do not induce pain, and there is a specific trigger point called the "trigger zone," where touching it can provoke a pain episode.

3. Acute Maxillary Sinusitis Patients with acute maxillary sinusitis often seek treatment for maxillary toothache. Because the roots of the maxillary posterior teeth are close to the floor of the maxillary sinus, and the dental pulp nerves of these teeth pass through the lateral wall and floor of the sinus before entering the apical foramen, infections in the maxillary sinus often cause neuralgia in the maxillary posterior teeth, with referred pain to the ipsilateral head and face, resembling acute pulpitis. Therefore, differentiation is necessary. The characteristics of acute maxillary sinusitis include persistent distending pain that may affect the maxillary canine, premolar, and molar regions. Percussion tenderness is present. Patients often have a history of headache, nasal obstruction, and purulent nasal discharge. Examination reveals tenderness over the anterior wall of the maxillary sinus. If suppuration occurs, puncture of the paranasal sinus may yield pus.

4. Chronic Hyperplastic Pulpitis

(1) Gingival Polyp Often formed by gingival tissue growing into a cavity due to proximal caries. Upon examination, the polyp's stalk is found to be connected to the gingiva when probed.

(2) Periodontal Membrane Polyp Due to extensive destruction by caries in multi-rooted teeth, perforation of the pulp floor, or furcation involvement, long-term chronic stimulation leads to hyperplasia of the periodontal membrane, which grows into the cavity to form a periodontal membrane polyp. The polyp's stalk is connected to the periodontal membrane. Probing can reach the pulp floor and extend to the furcation, but probing pain is not significant.

5. Chronic Closed Pulpitis

(1) Deep Caries The affected tooth is sensitive to hot, cold, sweet, and sour stimuli but has no spontaneous pain. Probing the deep cavity is sensitive, with no percussion pain. Thermal tests are sensitive, and electric pulp testing shows normal results.

(2) Pulp Hyperemia The affected tooth is sensitive to hot and cold stimuli, especially cold, with no spontaneous pain. The pain is sharp in nature. There is no percussion pain, and electric pulp testing readings are lower than normal. {|108|}