Perio 5: Etiology & Risk Factors of Periodontal Diseases

Etiology

The cause of a disease

Risk factor

Modifying characteristic that is associated with an increased chance of developing a disease

Plaque, smoking, dental restorations

Extrinsic factors

Genetics, age, gender, race, diabetes, tooth anatomy

Intrinsic factors

Cause unknown

Idiopathic factors

No (genetics, idiopathic factors)

For some people, only gingivitis develops, but for others, it progresses to periodontitis. Does this always correspond to the amount of plaque?

Positive

Development of deeper pockets creates a ________ feedback loop.

1. Gram - anaerobes

2. Inflammatory response (PGE2, IL1B, collagenase)

3. Destruction of PDL and bone

4. Deeper periodontal pockets

How does bacteria and inflammation cause periodontitis?

Negative

Deeper pockets contain more bacteria, more gram _________ anaerobe bacteria, and are harder to keep clean.

Red complex bacteria

Primary causative agents

False; by the body's immune response to the bacteria

T/F: Tissue damage is directly caused by bacteria.

P. gingivalis

T. forsythensis

T. denticola

Red complex bacteria

Periodontal pocket formation

Gingival recession

Root exposure

Bone loss

Tooth loosening

Tooth loss

Periodontal attachment loss leads to:

True

T/F: In attachment loss, both soft and hard tissues are affected.

False; inflammation only, no attachment loss + no bone loss

T/F: In gingivitis, there is inflammation and attachment loss but no bone loss.

True

T/F: In periodontitis, there is inflammation, attachment loss, and bone loss.

Symbiosis

Coexistence of two organisms, which may be beneficial to one or the other

Biofilm in a healthy mouth

Example of symbiosis

Dysbiosis

Imbalance of bacteria and the host; in this case, a disproportionate immune response to periodontal bacteria causes tissue injury and bone loss

Plaque and calculus removal -> controlled inflammatory response -> no destruction -> normal periodontal sulcus

How do you decrease bacterial load to disrupt positive feedback loop?

Brushing

Flossing

Prophylaxis

Plaque and calculus removed by:

Smoking + diabetes

Major risk factors for periodontitis

Impaired immune response

Increased prevalence of periodontal pathogens

Impaired healing

Mechanisms of negative effects of smoking on the periodontium

Neutrophil chemotaxis and phagocytosis impaired

Decreased IgG antibody production

Decreased B-helper lymphocyte numbers

Describe the impaired immune response seen in smokers.

Normal: < 100 mg/dl

Hyperglycemic: > 126 mg/dl

Normal fasting glucose vs. hyperglycemic

Normal: > 5.7%

Therapeutic target: < 6.5%

Normal HbA1c vs. therapeutic target

2.3x

Relative risk of periodontal disease for diabetics

Vascular changes

Altered host immune response

Alteration in CT metabolism

How does diabetes damage tissues?

True

T/F: Diabetes increases risk of periodontal disease.

False

T/F: Genetics is a main contributor to peridontal disease.

Polymorphic IL-1

There is a specific genotype of the __________ ___ gene cluster that was associated with severity of periodontitis in non-smokers.

IL-1 and TNF-a

Key regulators of the host response to microbial infection during periodontal pathogenesis

Greater

Increased production of IL-1 may result in _______ periodontal tissue destruction.

False; the age effect is likely due to cumulative effect of prolonged exposure to true risk factors

T/F: Periodontitis is an inevitable consequence of aging.

False; gingival recession is responsible

T/F: Pocket depth is responsible for increased attachment loss with aging.

False

T/F: There is a statistically significant difference between men and women and periodontitis prevalence.

Mexican-Americans

Non-Hispanic blacks

In the US, which groups show higher prevalence of periodontitis?

Obesity

Poor nutrition

Alcohol

Medications

Blood diseases

Other minor risk factors

Greater

Alveolar bone loss was found _______ around overhanging restorative margins and defective restorations.

Less

Open interproximal contacts in class II restorations were found to be associated with ____ alveolar bone height.

Subgingival calculus

___________ _______ is always covered with a non-mineralized layer of plaque. The non-mineralized plaque on the calculus surface is a principal irritant, but the underlying calcified portion may be a significant contributing factor.

NCCLs

Frequently seen as horizontal non-carious v-shaped grooves along the gingival margin. Most likely caused by dramatic brushing and can cause gingival recession and root sensitivity

False

T/F: Occlusal trauma alone causes periodontitis.

Cervical enamel projection

Radical groove

Local contributing factors - tooth anatomy