**Question:** A tooth with a 3 month history of pain, which was worse when hot liquid were in mouth. After extraction, the tooth was split open. The pulp chamber was completely filled with pus. A few remnants of pulp tissue were found in apical end. The condition is:

A. Pulpitis
B. Apical periodontitis
C. Endodontic abscess
D. Gum disease

**Core Concept:**

The question is describing a clinical scenario involving a tooth with a history of pain exacerbation upon exposure to hot liquids, pulp chamber filled with pus, and remnants of pulp tissue in the apical end. This combination of symptoms and findings is indicative of an infection in the dental pulp, specifically related to the structures involved in the process.

**Why the Correct Answer is Right:**

The correct answer is C: **Endodontic abscess**. Endodontic infections occur within the dental pulp, which is the soft tissue inside the tooth. When the pulp becomes infected, it leads to inflammation and tissue damage, causing pain and swelling. In this scenario, the tooth's pain is exacerbated by hot liquids, suggesting that the infection is affecting the dental pulp. The presence of pus within the pulp chamber confirms the infection has spread beyond the pulp and into the root canal system, leading to an abscess formation. The remnants of pulp tissue found at the apical end further supports the diagnosis of endodontic abscess, as these are typically present in cases of apical periodontitis, which is a complication of an untreated endodontic infection.

**Why Each Wrong Option is Inaccurate:**

A) Pulpitis (A) is an incorrect answer because it refers to inflammation of the dental pulp, not an infection causing abscess formation.

B) Apical periodontitis (B) does not directly address the issue of an abscess. Apical periodontitis is an infection confined to the root canal system, which is different from the described condition involving pus in the pulp chamber and remnants of pulp tissue at the apical end.

D) Gum disease (D) is not the correct answer because it pertains to periodontal infections, which occur in the gum tissues surrounding the tooth and are not the same as the described endodontic infection within the dental pulp.

**Clinical Pearl:**

A dental abscess is a result of a severe endodontic infection, a complication of an untreated dental pulp infection. The presence of pus in the pulp chamber and remnants of pulp tissue at the apical end strongly suggests endodontic abscess. Understanding the distinction between pulpitis, apical periodontitis, gum disease, and endodontic abscess is crucial for accurate diagnosis and appropriate treatment planning.