Which calculator do you need?
| You want to… | Use | Based on |
|---|---|---|
| Write a 2017 periodontitis diagnosis with stage, grade and extent | Periodontitis Staging & Grading | Tonetti, Greenwell & Kornman 2018; AAP/EFP chart |
| Score caries experience for one patient, or a whole survey | DMFT / DMFS Calculator | WHO Oral Health Surveys, 2013; Bratthall 2000 (SiC) |
| Record debris and calculus on six surfaces | OHI-S Calculator | Greene & Vermillion 1964 |
| Grade gum inflammation | Gingival Index | Löe & Silness 1963 |
| Grade plaque at the gum margin | Plaque Index | Silness & Löe 1964 |
| Check the maximum local anesthetic dose, including several agents in one visit | Local Anesthetic Max Dose | FDA labels; Becker & Reed 2012; AAPD 2023 |
| Rate a patient's caries risk and get a prevention plan | Caries Risk Assessment | Our checklist from CAMBRA, ADA and AAPD factors |
| Compare upper and lower tooth widths | Bolton Analysis | Bolton 1958 |
| Estimate dental age from tooth development stages | Dental Age (Demirjian) | Demirjian, Goldstein & Tanner 1973 |
Key facts at a glance
| Index | Range | What sets the score |
|---|---|---|
| Periodontitis stage | I–IV | Interdental CAL first (bone loss if no CAL), then the highest stage any tooth-loss or complexity factor points to |
| Periodontitis grade | A–C | Direct evidence, else % bone loss ÷ age (0.25 and 1.0 cut-offs); smoking and HbA1c only raise it |
| Extent | Localized / generalized | Under 30% of teeth involved is localized; a molar/incisor pattern is named separately |
| DMFT | 0–32 | D + M + F; M counts only caries losses under age 30, any loss from 30 |
| DMFS | 0–148 | 5 surfaces on back teeth, 4 on front teeth (a convention, not a WHO figure) |
| OHI-S | 0–6 | DI-S + CI-S, each from 6 surfaces scored 0–3 |
| GI and PlI | 0–3 | 4 areas per tooth on 16, 12, 24, 36, 32 and 44, averaged |
| Bolton ratios | Overall 91.3% ± 1.91; anterior 77.2% ± 1.65 | Mandibular ÷ maxillary widths × 100, 12 and 6 teeth |
| Demirjian maturity score | 0–100 | 7 left mandibular teeth staged 0/A–H, sex-specific scores, converted to age 3.0–16.0 |
| Epinephrine per appointment | 0.2 mg healthy; 0.04 mg cardiovascular-compromised | 1:100,000 = 0.01 mg/mL |
Clinical calculators
Four tools go beyond indices. The local anesthetic calculator converts every published limit to mg for the patient's weight and uses the lowest. It rounds down, never up, and is for licensed clinicians. The caries risk assessment uses our own checklist, because the CAMBRA and ADA forms can't be reproduced. A plain rule replaces point scores, and a sourced prevention plan follows. The Bolton and Demirjian calculators take measurements or stages from casts and radiographs, and show every step of the arithmetic.
How we build these tools
Index calculators are only useful if they're right, so we hold ours to a few rules:
- Original sources first. We read the original papers and the WHO manual, and paraphrase their criteria. We don't copy charts or artwork.
- Rules you can see. Each calculator shows its working: the sums and divisions, the rounding, and for perio staging a reasoning trail that names the finding that set the stage and the grade.
- Tested against worked examples. The logic runs against hand-computed cases and, for staging and grading, against published cases from Tonetti 2018 and a 2021 case series in the Journal of the Irish Dental Association. We test boundaries such as CAL of 2 vs 3 mm, a bone loss/age ratio of exactly 1.0, age 29 vs 30 for DMFT, and more.
- Conventions labeled. Good / fair / poor bands for the OHI-S and PlI aren't in the original papers, so we show them as conventions. The GI bands follow the groups Löe and Silness used to describe their patients. We round the way the bands are printed, and always give the number.
- Ambiguities stated. Where a source is silent, we say what we chose. Two examples are the SiC index when a group doesn't split evenly into thirds, and staging when CAL and bone loss disagree.
For students
Each page has a worked example pre-filled, so you can check your own hand calculation against it. The record tables and chart notes print cleanly for case write-ups. Tooth numbers are shown in FDI with Universal alongside, and the Tooth Number Chart converts between FDI, Universal and Palmer.
Privacy
All calculations run in your browser. Nothing you type is sent to a server or saved. Shared links hold scores and settings only, never names or birth dates.
Frequently asked questions
How do I stage and grade periodontitis?
First confirm it's a periodontitis case. Set the initial stage from interdental CAL at the worst site (bone loss only if CAL isn't available), then let tooth loss and complexity factors raise it. Grade from direct evidence, or from % bone loss ÷ age, then let smoking and diabetes raise it. The staging and grading calculator shows every step.
Do missing teeth always count in DMFT?
No. Under the WHO 2013 rules, only teeth lost to caries count before age 30. From 30, teeth missing for any reason count. The DMFT calculator applies the rule from the age you enter.
How many cartridges of local anesthetic can I give?
It depends on the agent, the patient's weight, the cartridge volume and the epinephrine limit. The local anesthetic dose calculator applies the FDA label, a peer-reviewed review and, for children, the AAPD table, uses the lowest, and subtracts what you've already given. It's for licensed clinicians; always check the product label.
What's the difference between the OHI-S, the Plaque Index and the Gingival Index?
The OHI-S scores how much of six surfaces is covered by debris and calculus. The Plaque Index scores plaque thickness at the gum margin. The Gingival Index scores inflammation, not deposits.
Are the good / fair / poor bands part of the original indices?
Mostly not. Greene and Vermillion (1964) and Silness and Löe (1964) gave scoring methods but no interpretation bands; the OHI-S and Plaque Index bands are later teaching conventions. The Gingival Index bands (mild, moderate, severe) come from the groups Löe and Silness (1963) used to describe their patients' average scores. Our calculators label where each band comes from and always give the number too.
Is my patient data stored or sent anywhere?
No. Everything runs in your browser. Copy-link shares carry scores and settings only, never names or dates of birth.
How do I cite these calculators?
Cite the original paper or manual for the index itself; each calculator lists it under Sources. If you also cite the calculator, give its name, the site, the web address and the date you used it, for example: Dental Health Time. DMFT / DMFS Calculator. https://dentalhealthtime.com/pro/dmft-calculator/ (accessed October 26, 2026).
Sources
- Tonetti MS, Greenwell H, Kornman KS. Journal of Clinical Periodontology 45(Suppl 20):S149-S161. Staging and grading of periodontitis: Framework and proposal of a new classification and case definition. 2018. Accessed October 26, 2026.
- World Health Organization (Petersen PE, Baez RJ). Oral health surveys: basic methods, 5th edition. 2013. Accessed October 26, 2026.
- Greene JC, Vermillion JR. Journal of the American Dental Association 68:7-13. The Simplified Oral Hygiene Index. 1964. Accessed October 26, 2026.
- Löe H, Silness J. Acta Odontologica Scandinavica 21:533-551. Periodontal disease in pregnancy. I. Prevalence and severity. 1963. Accessed October 26, 2026.
- Silness J, Löe H. Acta Odontologica Scandinavica 22:121-135. Periodontal disease in pregnancy. II. Correlation between oral hygiene and periodontal condition. 1964. Accessed October 26, 2026.
- Bratthall D. International Dental Journal 50(6):378-384. Introducing the Significant Caries Index together with a proposal for a new global oral health goal for 12-year-olds. 2000. Accessed October 26, 2026.
- American Academy of Pediatric Dentistry. The Reference Manual of Pediatric Dentistry 2025:407-14. Use of Local Anesthesia for Pediatric Dental Patients (latest revision 2023). 2023. Accessed October 26, 2026.
- Featherstone JDB, Crystal YO, Alston P, et al. Frontiers in Oral Health 2:657518. Evidence-Based Caries Management for All Ages-Practical Guidelines. 2021. Accessed October 26, 2026.
- American Academy of Pediatric Dentistry. The Reference Manual of Pediatric Dentistry 2025:325-31. Caries-risk Assessment and Management for Infants, Children, and Adolescents (latest revision 2022). 2022. Accessed October 26, 2026.
- Bolton WA. The Angle Orthodontist 28(3):113-130. Disharmony in tooth size and its relation to the analysis and treatment of malocclusion. 1958. Accessed October 26, 2026.
- Demirjian A, Goldstein H. Annals of Human Biology 3(5):411-421. New systems for dental maturity based on seven and four teeth. 1976. Describes the original 1973 seven-tooth system used by the dental age calculator. Accessed October 26, 2026.
- Godzieba A, Smektała T, Jędrzejewski M, Sporniak-Tutak K. Medical Science Monitor 20:393-398. Clinical assessment of the safe use local anaesthesia with vasoconstrictor agents in cardiovascular compromised patients: a systematic review. 2014. States the maximum epinephrine dose as 0.2 mg for a healthy subject, lowered to 0.04 mg with severe cardiovascular disease (ASA III and IV). Accessed October 26, 2026.
Last reviewed by the Dental Health Time editorial team, against the sources above. How we review.