Caries Risk Assessment
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Direct answer
Risk assessment sorts every patient into low, moderate or high caries risk before deciding recall intervals, fluoride intensity and restorative strategy — because restorations fail in high-risk mouths regardless of material. The two named systems are CAMBRA (Caries Management by Risk Assessment, with its disease indicators, risk factors and protective factors) and the Cariogram, a Swedish software model by Bratthall that expresses ten interacting factors as a "chance of avoiding new lesions" sector diagram. High-risk markers the exam expects verbatim: two or more new lesions in the last twelve months, stimulated saliva flow below about 0.7 ml per minute, frequent between-meal sugar exposure, low fluoride exposure, and medical states such as xerostomia or radiation therapy.
What you must remember
- CAMBRA triad: disease indicators (new lesions in 12 months, active white spots, lesions within a year of restoration), risk factors (diet frequency above three sugar exposures daily, Streptococcus mutans and lactobacilli counts, poor plaque control, xerostomia), protective factors (fluoride exposure, saliva, antibacterial therapy).
- Cariogram sectors: diet, bacteria, susceptibility and circumstances combine into a pie whose green sector is the chance of avoiding new caries — the only interactive validated model commonly quoted.
- Saliva thresholds: unstimulated flow below roughly 0.1-0.2 ml per minute or stimulated flow below 0.5-0.7 ml per minute defines hyposalivation and pushes the patient into high risk.
- Buffering capacity and bacterial counts (mutans streptococci, lactobacilli on dip-slide tests) are the laboratory arm of risk assessment.
- Recall intervals follow risk: high risk three months, moderate six months, low risk twelve months or longer — the NICE recall guidance range of 3-24 months is the quoted convention.
- High-risk intervention package: fluoride varnish 5 per cent sodium fluoride (22,600 ppm) two to four times yearly, chlorhexidine gel courses where indicated, diet counselling, and glass ionomer sealants in stagnation zones.
- Social and medical determinants matter: socioeconomic status, disability, orthodontic appliances, Sjögren syndrome, diabetes and anti-cholinergic drugs all shift the category.
Triaging a returning patient
A 30-year-old teacher returns with five new lesions in a year, one under a two-year-old composite. Work the domains: diet diary reveals six sugar exposures including sweetened coffee hourly; stimulated saliva measures 0.5 ml per minute with low buffering; plaque index poor; no fluoride beyond toothpaste. CAMBRA classifies extreme/high risk, the Cariogram's green sector would sit under 20 per cent. The plan then writes itself in the order the viva wants: control the bacterial load first — chlorhexidine gel and plaque control; correct the saliva-diet axis — diet counselling targeting frequency not quantity, sugar-free chewing gum for stimulation; harden the teeth — 22,600 ppm varnish three-monthly plus 5,000 ppm fluoride toothpaste at home; restore with glass ionomer or high-fluoride-releasing materials where margins sit in plaque stagnation zones; and re-evaluate at three months with new lesion count as the outcome measure. Note the teaching point: the composite did not fail because it was composite — it failed because the mouth was a caries-active environment, and every subsequent restoration would share that fate until the risk category moved.
How the exam frames it
NEET-MDS stems usually ask which single finding pushes a patient from moderate to high risk — the safest answer is "two or more new lesions in twelve months", because demonstrated disease outranks any laboratory number. The Cariogram appears as a match-the-following question on its ten factors, so learn the four domains: diet, bacteria, susceptibility, circumstances. A favourite negative stem: "which is NOT a caries risk factor" with fluoride exposure as the answer. Indian exam convention also expects the microbiology pairing — Streptococcus mutans for initiation, Lactobacillus for progression — imported from oral microbiology into risk assessment answers. Finally, remember that recall interval is an output of risk assessment, not a default six-month habit; saying "every patient six months" loses the modern-practice mark.
Frequently asked questions
Which single indicator most strongly suggests high caries risk?
Two or more new lesions (including root or secondary caries) within the past twelve months — demonstrated disease beats every surrogate measure.
What does the Cariogram display?
A sector diagram where the green sector shows the per cent "chance of avoiding new caries", computed from ten diet, bacteria, susceptibility and circumstance factors.
What saliva flow rates define hyposalivation?
Unstimulated flow below about 0.1-0.2 ml per minute or stimulated flow below 0.5-0.7 ml per minute, commonly quoted thresholds in risk assessment texts.
How does risk category change the recall interval?
High-risk patients are reviewed at about three months, moderate at six, and low-risk patients may extend to twelve months or beyond per individualised recall guidance.
Which bacteria dominate initiation versus progression of caries?
Streptococcus mutans drives initiation and enamel lesions, while lactobacilli dominate the acidic, progressive dentine lesion environment.