❤️ Clinical Calculators

Periodontal Risk Assessment

Evidence-based periodontal risk classification using the validated Lang & Tonetti PRA framework. Evaluates 6 clinical parameters to classify Low, Moderate, or High risk — with recall interval and maintenance protocol guidance.

Lang & Tonetti PRA 6 Parameters Low / Moderate / High Recall Interval PDF Export
Periodontal Risk Assessment
Lang & Tonetti PRA (2003) · Validated Framework
Enter 6 PRA Parameters

Each parameter is scored 1 (Low), 2 (Moderate), or 3 (High). The highest scoring parameter determines overall risk in the Lang & Tonetti PRA model.

1. Bleeding on Probing (BOP %)
Percentage of sites that bleed on probing
Low
Low (<10%)Moderate (10–25%)High (>25%)
2. Prevalence of Pockets ≥5 mm
Proportion of sites with probing depth ≥5 mm
Low
Low (≤4 sites)Moderate (5–8 sites)High (≥9 sites)
3. Bone Loss / Age Ratio
% worst bone loss ÷ patient age
Low
Low (<0.5)Moderate (0.5–1.0)High (>1.0)
4. Tooth Loss Due to Periodontitis
Number of teeth lost due to periodontal disease (exclude caries/ortho/trauma)
Low
Low (≤4 teeth)Moderate (5–9)High (≥10)
5. Systemic/Genetic Conditions
Diabetes, IL-1 genotype, osteoporosis, immunosuppression
Low
Low (None)Moderate (Controlled)High (Uncontrolled)
6. Cigarette Smoking
Current smoking status and quantity
Low
Low (Non-smoker)Moderate (<20/day)High (≥20/day)

❤️ Periodontal Risk Results

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Risk Level
—
—
Highest Parameter
—
Drives overall risk
Recall Interval
—
Supportive care frequency
Maintenance Protocol
—
Recommended approach
Parameter Scores
Maintenance Protocol
Clinical Disclaimer: This assessment uses the Lang & Tonetti (2003) PRA framework and provides guidance only. It does not replace clinical examination, full periodontal charting, radiographic assessment, and clinical judgment. Refer to current EFP (European Federation of Periodontology) and AAP guidelines for full classification and treatment protocols.

The Lang & Tonetti Periodontal Risk Assessment

The Lang & Tonetti PRA (2003) is the most widely used and validated periodontal risk assessment tool in specialist practice worldwide. It evaluates six parameters and classifies patients as Low, Moderate, or High risk — determining the appropriate recall interval and intensity of supportive periodontal therapy (SPT).

Use this tool at each supportive care appointment to track risk trajectory over time. Patients with reducing risk scores over consecutive assessments are responding well to treatment. Increasing or persistent high scores indicate inadequate disease control requiring active treatment modification. For patients with uncontrolled systemic risk factors, our Blood Pressure Dental Risk Checker and BMI & Oral Health Risk Calculator provide complementary systemic risk assessment.

The Six PRA Parameters Explained

  • Bleeding on Probing (BOP%): The primary indicator of current inflammatory activity. BOP <10% = low risk; 10–25% = moderate; >25% = high. BOP is the most modifiable parameter — it responds directly to improved oral hygiene and professional debridement.
  • Prevalence of pockets ≥5 mm: Deep pockets represent residual disease or reinfection sites. Four or fewer sites = low; 5–8 sites = moderate; 9+ sites = high.
  • Bone loss/age ratio: Bone loss expressed as a percentage of root length divided by patient age. A ratio >1.0 indicates bone loss is occurring faster than expected for age — high-risk indicator.
  • Tooth loss due to periodontitis: Historical tooth loss from periodontal disease indicates disease severity and susceptibility. Up to 4 teeth = low; 5–9 = moderate; 10+ = high.
  • Systemic/genetic conditions: Diabetes mellitus, genetic susceptibility (IL-1 genotype positive), osteoporosis, and immunosuppression all amplify periodontal risk. None = low; controlled = moderate; uncontrolled = high.
  • Cigarette smoking: Smoking is a major modifiable periodontal risk factor, masking BOP, impairing healing, and accelerating bone loss. Non-smoker = low; <20/day = moderate; ≥20/day = high.

Frequently Asked Questions

The Lang & Tonetti PRA recommends recall intervals based on risk classification: Low risk = every 12 months; Moderate risk = every 6 months; High risk = every 3 months. These are minimum frequencies — clinical judgment may indicate more frequent visits for individual patients. The interval should be re-evaluated at each visit as risk may change with treatment response.
Yes — significantly. Smoking is one of the strongest modifiable risk factors for periodontitis. Smokers have 2–3 times greater risk of periodontitis than non-smokers and respond less well to all forms of periodontal therapy. Critically, smoking suppresses bleeding on probing — a high BOP% in a smoker indicates severe disease. Smoking cessation substantially improves treatment outcomes and should be addressed at every periodontal appointment.

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