What factor is primarily relevant to the development of gingivitis?

Bacterial plaque is considered the primary factor relevant to the development of gingivitis. This is because bacterial plaque, a sticky film composed of bacteria and their byproducts, builds up on the teeth and gums. When oral hygiene practices are inadequate, this plaque can lead to inflammation of the gingival tissue, resulting in gingivitis. The bacteria present in plaque release toxins that irritate the gums, causing redness, swelling, and bleeding, which are characteristic signs of gingivitis.

While other factors like carbohydrate foods can contribute to the formation of plaque, especially when they remain on teeth for prolonged periods, they are not direct causes of gingivitis. Instead, they may facilitate the conditions for plaque accumulation. Similarly, frequency of acid attacks and weak organic acids relate to dental erosion and cavities but do not directly initiate the inflammatory process seen in gingivitis. Thus, the presence of bacterial plaque is the most critical element leading to the development of this gum disease.