# Periodontal Diagnosis Calculator — Full Reference

> Free clinical decision-support tool that computes the EFP/AAP 2017 periodontal diagnosis (staging I–IV and grading A–C), the Lang–Tonetti Periodontal Risk Assessment (PRA), supportive-therapy recall intervals, and post-treatment stability from clinical parameters. Bilingual (English / Italian). No patient data is stored.

- URL: https://perio.bonebenders.com/
- Author: Dr. Ernesto Bruschi — periodontist, implantologist, oral surgeon (ORCID 0000-0002-4773-5384)
- Publisher: Bonebenders (https://bonebenders.com/)
- Languages: Italian (`?lang=it`, default), English (`?lang=en`)
- Cost: free; no login required for global mode
- Privacy: no patient data is stored or logged; see "Data flow & privacy" below

## What the tool does

From clinical and radiographic parameters it returns, in real time:

1. The **EFP/AAP 2017 diagnosis** — stage (I–IV) and grade (A–C), plus extent/distribution.
2. The **Lang–Tonetti (2003) Periodontal Risk Assessment (PRA)** — an individual progression-risk score across six factors.
3. A **personalised recall interval** (2–12 months) for supportive periodontal therapy.
4. A **post-treatment stability** assessment (stable / in remission / unstable).
5. Global, per-sextant and per-tooth charting modes, with a printable report and periodontal chart.

## EFP/AAP 2017 staging (severity and complexity)

Stage is set by the **worst** site and by complexity factors.

- **Stage I (initial):** interdental CAL 1–2 mm; radiographic bone loss (RBL) in the coronal third (<15%); no tooth loss from periodontitis; maximum probing depth ≤4 mm; mostly horizontal bone loss.
- **Stage II (moderate):** interdental CAL 3–4 mm; RBL in the coronal third (15–33%); no tooth loss from periodontitis; maximum probing depth ≤5 mm.
- **Stage III (severe, with potential for additional tooth loss):** interdental CAL ≥5 mm; RBL extending to the mid-third of the root or beyond; ≤4 teeth lost to periodontitis; complexity factors may include probing depth ≥6 mm, vertical bone defects ≥3 mm, furcation involvement class II/III, moderate ridge defects.
- **Stage IV (severe, with potential for loss of dentition):** as Stage III plus complexity from masticatory dysfunction — secondary occlusal trauma (tooth mobility ≥ grade 2), severe ridge defects, bite collapse/drifting/flaring, ≥5 teeth lost to periodontitis, fewer than 20 remaining teeth (10 opposing pairs).

## EFP/AAP 2017 grading (rate of progression)

Grade starts at B and is shifted by direct/indirect evidence and by modifiers.

- **Grade A (slow):** no bone loss over 5 years, or bone-loss-percentage/age ratio <0.25; non-smoker; no diabetes.
- **Grade B (moderate):** bone-loss/age ratio 0.25–1.0; smoker <10 cigarettes/day; diabetes with HbA1c <7.0%.
- **Grade C (rapid):** bone-loss/age ratio >1.0; smoker ≥10 cigarettes/day; diabetes with HbA1c ≥7.0%.

Modifiers (smoking ≥10 cig/day, diabetes HbA1c ≥7%) shift the grade upward toward C.

## Extent and distribution

- **Localised:** <30% of teeth involved.
- **Generalised:** ≥30% of teeth involved.
- **Molar–incisor pattern:** characteristic distribution affecting molars and incisors.

## Periodontal Risk Assessment (PRA) — Lang & Tonetti 2003

The PRA plots six vectors on a functional radar diagram to stratify the individual risk of progression in supportive periodontal therapy:

1. **Bleeding on probing (BOP):** percentage of sites that bleed on probing.
2. **Residual pockets ≥5 mm:** number of residual deep pockets.
3. **Tooth loss:** number of teeth lost (out of 28, excluding third molars).
4. **Bone loss / age ratio:** radiographic bone loss at the worst posterior site divided by patient age.
5. **Systemic and genetic conditions:** e.g. IL-1 polymorphism, immunosuppression, poorly controlled systemic disease.
6. **Environmental factors:** smoking.

The overall profile yields a **low**, **moderate**, or **high** risk category, which drives the recall frequency.

## Recall interval logic (used by this tool)

Baseline from PRA risk:

- **Low risk →** 6–12 months.
- **Moderate risk →** 4–6 months.
- **High risk →** 2–3 months.

Then capped (shortened) by:

- **Stage IV →** maximum 4 months.
- **Grade C →** maximum 4 months.
- **Post-treatment instability →** maximum 3 months.

## Post-treatment stability (2018 consensus)

- **Stable:** BOP <10%, probing depths ≤4 mm, no 4 mm site bleeding on probing, no progressive bone loss.
- **In remission/control:** BOP ≥10% but probing depths ≤4 mm and no 4 mm sites bleeding on probing.
- **Unstable:** probing depth ≥5 mm, or ≥4 mm with BOP, or progressive bone loss.

## Data flow & privacy

- Clinical inputs and results stay in the browser; **no patient data is stored** on any server.
- Full privacy notice: https://bonebenders.com/privacy/

## Clinical guides on this site

- EFP/AAP 2017 staging & grading (IT): https://perio.bonebenders.com/guide/efp-aap-2017/
- EFP/AAP 2017 staging & grading (EN): https://perio.bonebenders.com/en/guide/efp-aap-2017/
- Lang–Tonetti PRA explained (IT): https://perio.bonebenders.com/guide/pra-lang-tonetti/
- Lang–Tonetti PRA explained (EN): https://perio.bonebenders.com/en/guide/pra-lang-tonetti/
- Recall intervals in SPT (IT): https://perio.bonebenders.com/guide/intervalli-richiamo/
- Recall intervals in SPT (EN): https://perio.bonebenders.com/en/guide/intervalli-richiamo/
- Essential periodontal glossary (IT): https://perio.bonebenders.com/guide/glossario/
- Essential periodontal glossary (EN): https://perio.bonebenders.com/en/guide/glossario/

## Frequently asked questions

**What is periodontal screening?** A systematic clinical assessment that identifies periodontal disease early: probing of the gingival pockets, bleeding on probing, clinical attachment loss and, when indicated, radiographic analysis of bone loss.

**What is the EFP/AAP 2017 classification (staging and grading)?** The 2017 World Workshop describes periodontitis by stage (I–IV: severity and complexity) and grade (A–C: rate of progression). It replaced the 1999 Armitage classification. See also https://perio.bonebenders.com/guide/efp-aap-2017/

**What is the Periodontal Risk Assessment (PRA)?** The Lang & Tonetti (2003) PRA stratifies the individual risk of progression in supportive periodontal therapy using six factors and drives the recall interval. See also https://perio.bonebenders.com/guide/pra-lang-tonetti/

**How are recall intervals determined?** The interval (2–12 months) is derived from the overall PRA risk and adjusted for stage IV, grade C and post-treatment instability. See also https://perio.bonebenders.com/guide/intervalli-richiamo/

## Disclaimer

This tool does not replace a specialist examination. It is a clinical decision-support aid, to be interpreted within professional judgement.

## References

- Lang NP, Tonetti MS. Periodontal risk assessment (PRA) for patients in supportive periodontal therapy. Oral Health Prev Dent. 2003;1(1):7-16. https://pubmed.ncbi.nlm.nih.gov/15643744/
- Tonetti MS, Greenwell H, Kornman KS. Staging and grading of periodontitis. J Periodontol. 2018;89 Suppl 1:S159-S172. https://pubmed.ncbi.nlm.nih.gov/29926952/
- Papapanou PN, Sanz M, et al. Periodontitis: consensus report of workgroup 2 of the 2017 World Workshop. J Periodontol. 2018;89 Suppl 1:S173-S182. https://pubmed.ncbi.nlm.nih.gov/29926951/
- Matuliene G, et al. Influence of residual pockets on progression of periodontitis and tooth loss. J Clin Periodontol. 2008;35(8):685-695. https://pubmed.ncbi.nlm.nih.gov/18549447/
- Tonetti MS, Sanz M. Implementation of the new classification of periodontal diseases: decision-making algorithms. J Clin Periodontol. 2019;46(4):398-405. https://pubmed.ncbi.nlm.nih.gov/30883878/

## Related reading

- Article (EN): https://bonebenders.com/en/blog/periodontal-screening-diagnosis-calculator/
- Article (IT): https://bonebenders.com/blog/il-nuovo-calcolatore-per-la-diagnosi-parodontale/