Australian Dental Council (ADC) Practice Test 2025 - Free ADC Practice Questions and Study Guide

The initiation of gingivitis most commonly occurs in the interdental papillae because this area is particularly susceptible to plaque accumulation and irritation. The interdental papillae, which are the triangular areas of gum tissue between the teeth, are often challenging to clean thoroughly with standard brushing techniques. As a result, plaque can accumulate in these areas, leading to inflammation and the early stages of gingivitis.

Inflammation in the interdental papillae is typically more pronounced due to the proximity to food debris and bacteria, which thrive in these confined spaces. When plaque is present, it can trigger the body’s inflammatory response, resulting in swollen, red, and bleeding gums—hallmarks of gingivitis.

Considering the other areas: while marginal gingiva can also be involved in gingival diseases, the initiation point often starts between teeth. Attached gingiva and the free gingival ridge play roles in periodontal health, but the specific conditions of the interdental papillae make them the prime site for the onset of gingivitis. The anatomy and frequent neglect of this area in oral hygiene practices contribute to its status as the most common location for gingivitis initiation.