# Management of Discoloured Teeth

> Discoloured teeth for BDS Operative Dentistry — extrinsic and intrinsic causes, microabrasion, vital and non-vital bleaching, veneers and crowns.

- Canonical URL: https://prepelephant.com/topics/bds/operative-dentistry/discoloured-teeth-management
- Exam / course: BDS · Subject: Operative Dentistry
- Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team
- First published: 2026-10-02
- Last updated: 2026-10-02
- How to cite: "Management of Discoloured Teeth", PrepElephant, https://prepelephant.com/topics/bds/operative-dentistry/discoloured-teeth-management

## Direct answer

A single grey upper central incisor that went dark after a football injury is a different patient from a teenager with chalky-white and brown mottling across both arches: discolouration is classified as extrinsic (surface stains — tobacco, tea, chlorhexidine, chromogenic bacteria, iron syrups) or intrinsic (within enamel or dentine — fluorosis, tetracycline, pulp necrosis, dentinogenesis imperfecta, ageing), and the classification writes the treatment plan. Extrinsic stains polish or scale off; mild intrinsic fluorosis responds to microabrasion with 18% hydrochloric acid and pumice; vital bleaching uses 10% carbamide peroxide in a nightguard at home or 35–38% hydrogen peroxide in surgery; non-vital teeth receive the walking bleach with sodium perborate sealed between visits behind a cervical barrier. Veneers and crowns finish the ladder when bleaching cannot deliver.

## What you must remember

- Extrinsic stains: tobacco and paan products, tea and coffee, chlorhexidine (brown), iron supplements in children (black), chromogenic bacteria (green or black in children) — removed by scaling, polishing and habit change.
- Intrinsic pre-eruptive: dental fluorosis (optimum water fluoride about 1 ppm; endemic belts of India such as Nalgonda, Rajasthan and Gujarat drink water far above this), tetracycline (yellow-grey bands, deposited on forming dentine; avoid in pregnancy and under 8 years), amelogenesis and dentinogenesis imperfecta, erythropoietic porphyria (reddish), neonatal jaundice (greenish bilirubin).
- Intrinsic post-eruptive: pulp necrosis and haemoglobin breakdown (grey-black), internal resorption (pink spot), ageing dentine, root canal sealers and historic silver nitrate medicaments.
- Fluorosis severity is graded by Dean's index (normal through questionable, very mild, mild, moderate, severe) — the classic exam classification — and by the TF index for finer coding.
- Microabrasion (Croll technique: 18% hydrochloric acid mixed with pumice) removes a very shallow layer of surface enamel for white and brown fluorosis patches and idiopathic opacities.
- Vital bleaching: nightguard vital bleaching with 10% carbamide peroxide (about 3.5% hydrogen peroxide) overnight for two to four weeks — introduced by Haywood and Heymann in 1989; in-office bleaching uses 35–38% hydrogen peroxide with light or heat activation.
- Non-vital (walking) bleach: sodium perborate mixed with water or hydrogen peroxide, sealed in the chamber and refreshed over visits; a cervical barrier of about 2 mm of glass ionomer at the cementoenamel junction level guards against external cervical resorption — the feared complication, especially with heat and trauma history.
- Tetracycline staining bleaches poorly (banding sits deep in dentine) — veneers or crowns are realistic; severe fluorosis and dentinogenesis imperfecta likewise.

## Working through a non-vital discolouration

A 30-year-old wants the "dead-looking" upper left central incisor matched to its neighbours. The tooth turned grey two years after trauma; it is comfortable now, non-vital to thermal and electric tests, with a periapical radiograph showing either an intact lamina dura or early periapical change — either way, root canal treatment comes first, because bleaching an infected canal invites flare-ups. Complete the root canal, then cut the coronal gutta-percha back and seal a 2 mm glass ionomer barrier at the cementoenamel junction level. Mix sodium perborate with distilled water into a thick paste, pack the pulp chamber, and seal with a temporary zinc oxide eugenol or glass ionomer restoration, reviewing in about a week — refreshed until the shade overshoots slightly lighter than the neighbours. Protect the gingiva with petroleum jelly at each paste change, and finish with a composite seal of the access cavity. Consent mentions external cervical resorption as the rare late risk the barrier exists to prevent.

## Where students slip

The dangerous slip is bleaching before diagnosis: a single dark tooth may be necrotic, resorbing internally (the pink spot), or cracked — each demands its own treatment first, and vitality testing plus a periapical film are mandatory before any bleaching tray or walking bleach. The second error is classification mixing: writing chlorhexidine or tobacco under intrinsic staining, or fluorosis under extrinsic, halves the theory answer instantly. Third is the barrier omission in walking bleach answers — the cervical glass ionomer plug is the specific fact that distinguishes a prepared candidate, being the direct countermeasure to external inflammatory root resorption. Fourth is overpromising on tetracycline staining: honest answers state the deep dentinal banding limits bleaching, moving instead to veneers or full coverage.

## Frequently asked questions

### How are discoloured teeth classified?

Extrinsic (surface deposits and stains) versus intrinsic (within enamel or dentine, subdivided into pre-eruptive such as fluorosis and tetracycline, and post-eruptive such as pulp necrosis and ageing).

### What is the nightguard vital bleaching technique?

Home application of 10% carbamide peroxide gel in a custom tray, described by Haywood and Heymann in 1989, typically worn overnight for two to four weeks.

### Why is a cervical barrier placed in walking bleach?

To seal the dentinal tubules and cementum at the cementoenamel junction with about 2 mm of glass ionomer, preventing peroxide tracking down the root and triggering external cervical resorption.

### Which index grades fluorosis?

Dean's index — normal, questionable, very mild, mild, moderate, severe — with the Thylstrup–Fejerskov (TF) index for finer gradations.

### Which discolouration responds worst to bleaching?

Deep tetracycline banding and severe dentinogenesis imperfecta, because the chromophore lies deep within dentine — veneers or crowns are the realistic options.