What causes gum disease

Last updated: April 1, 2026

Quick Answer: Gum disease is primarily caused by bacterial plaque buildup on teeth, though risk factors include poor oral hygiene, smoking, diabetes, hormonal changes, and genetic susceptibility. The infection progresses from gingivitis to periodontitis if untreated.

Key Facts

The Bacterial Foundation

Gum disease fundamentally stems from bacterial infection in the mouth. Our mouths naturally contain hundreds of bacterial species, and while most are harmless, some are pathogenic. When these bacteria aren't regularly removed through proper oral hygiene, they accumulate into plaque—a sticky biofilm on tooth surfaces. This plaque continuously irritates gum tissue, triggering inflammation as the immune system attempts to fight the infection.

Progression from Gingivitis to Periodontitis

The disease follows a predictable progression. Initially, plaque causes gingivitis, characterized by swollen, red, and bleeding gums. At this stage, the infection affects only the gum tissue and is reversible with improved oral hygiene and professional cleaning. However, if untreated, the bacteria penetrate deeper, destroying the connective tissue and bone that support teeth. This advanced stage, called periodontitis, causes permanent damage and tooth loss if not treated. The destructive process can become self-sustaining, with inflammation releasing substances that further damage supporting structures.

Risk Factors and Susceptibility

Several factors increase gum disease risk beyond poor hygiene. Smoking is particularly damaging—it reduces saliva production that naturally protects gums and impairs the immune system's ability to fight infection. Diabetes creates a vicious cycle: high blood sugar increases inflammation and weakens immunity, while gum disease worsens blood sugar control. Hormonal changes during pregnancy, menstruation, and menopause temporarily increase gum disease risk. Certain medications that reduce saliva production also increase risk.

Genetic and Immune Factors

Genetic research has identified that approximately 30% of gum disease risk is inherited. Some people have immune systems that overreact to bacterial infection, causing excessive inflammation that damages tissue. Others have immune systems that inadequately respond to bacteria. These genetic variations mean some individuals develop severe disease despite excellent hygiene, while others maintain healthy gums despite less-than-perfect oral care. Understanding your genetic risk can motivate more vigilant prevention.

Nutritional and Lifestyle Contributions

Nutritional deficiencies, particularly of vitamin C, impair gum tissue integrity and immune function. Stress elevates cortisol levels that suppress immune response, making people more susceptible to infection. Poor overall health and chronic diseases compromise immune function. Alcohol consumption can contribute to oral health problems. While these factors don't directly cause gum disease, they create conditions where bacterial infection becomes more likely and severe.

Prevention Strategies

Prevention focuses on removing plaque daily through proper brushing twice daily with fluoride toothpaste and daily flossing, plus regular professional cleanings. Controlling modifiable risk factors—quitting smoking, managing diabetes, managing stress, and maintaining good nutrition—significantly reduces disease development and progression. Regular dental checkups allow early detection and treatment before irreversible damage occurs.

Related Questions

What is the difference between gingivitis and periodontitis?

Gingivitis is early-stage gum inflammation affecting only gum tissue and is reversible with proper treatment. Periodontitis is advanced disease where infection destroys bone and connective tissue supporting teeth, causing permanent damage and potential tooth loss.

How can you prevent gum disease?

Prevent gum disease through daily brushing with fluoride toothpaste, flossing, regular professional cleanings, not smoking, managing diabetes, reducing stress, eating nutritious foods, and maintaining overall health. Early detection through dental checkups is also crucial.

What are the complications of untreated gum disease?

Untreated gum disease leads to tooth loss, bone deterioration, and systemic health problems including heart disease, stroke, and diabetes complications. The chronic infection can spread bacteria to the bloodstream, affecting overall health.

Sources

  1. Wikipedia - Periodontal Disease CC-BY-SA-4.0
  2. CDC - Oral Health Public Domain