Minimal Invasive Dentistry
On this page
Direct answer
Cut less, remineralise more: minimally invasive dentistry replaces extension-for-prevention with a sequence — early detection, caries risk control, remineralisation of non-cavitated lesions, and surgical intervention only when cavitation or cleansability fails. Its operative vocabulary includes selective caries removal to firm dentine peripheral and leathery dentine central over the pulp, stepwise excavation, the atraumatic restorative technique (ART) with hand instruments and high-viscosity glass ionomer, preventive resin restorations, and chemical removal with papain-based or sodium hypochlorite gels. Even 38 per cent silver diamine fluoride now arrests lesions without any drill at all. The philosophy is examinable as a principle, not a product list: preserve tooth structure, preserve pulp, restore only what disease has destroyed.
What you must remember
- Selective caries removal levels: peripheral dentine excavated to hard (non-yielding to a sharp explorer), central dentine over the pulp left leathery or firm — infected tissue is removed, affected tissue is retained to avoid exposure.
- Stepwise excavation leaves affected dentine deliberately and re-enters after months (commonly quoted three to twelve) for final excavation — the two-stage cousin of one-visit selective removal.
- ART (Frencken): hand excavators only, no anaesthesia or drill, restored with high-viscosity glass ionomer (Fuji IX type) — the WHO-endorsed technique for field and rural settings, with single-surface success commonly reported above 80 per cent at several years.
- 38 per cent silver diamine fluoride arrests cavitated coronal lesions (repeated application, typically twice yearly) at the cost of permanent black staining — now in Indian postgraduate use.
- Chemomechanical removal: papain-gel (Papacarie) and hypochlorite-amino gel (Carisolv) liquefy infected carious dentine selectively, sparing sound tissue and often avoiding anaesthesia.
- Preventive resin restoration: invasive pits and fissures get a small composite restoration while remaining susceptible fissures are sealed in the same visit — a conservative overhaul of the classic Class I cavity.
- Remineralisation arsenal: 22,600 ppm fluoride varnish, CPP-ACP casein pastes, and 5,000 ppm home-use toothpaste for white spots.
Treating a deep lesion in a young molar
A 14-year-old's second molar: deep occlusal caries, no spontaneous pain, reversible pulpitis signs only, apex closed. Instead of the old excavate-everything-to-exposure routine: isolate, open the lesion conservatively, remove all caries at the periphery to hard dentine so margins seal on sound tissue, and over the pulp leave firm or leathery dentine even if it stains with caries detector. Line with glass ionomer, restore with composite, and review at six and twelve months with vitality tests and radiographs. If chosen stepwise rather than selective, the first appointment seals glass ionomer over the retained dentine and re-enters months later, when the lesion has arrested and tertiary dentine has formed, before definitive restoration. The decision logic to voice in the viva: infected dentine (soft, wet, mushy, bacteria-laden) must go; affected dentine (firm, discoloured, demineralised but remineralisable) can stay; the pulp's response is monitored clinically, not assumed. A carious exposure in this 14-year-old would have meant root canal treatment in a tooth that conservative excavation might have kept vital for life — the entire moral of the topic.
Where students slip
The recurring confusion is stepwise versus selective removal: stepwise intentionally re-enters after months, selective caries removal to firm dentine never re-enters — mixing them up costs the MCQ. Second, candidates describe ART as "temporary treatment"; ART restorations with high-viscosity glass ionomer are legitimate definitive single-surface restorations in indicated settings, and calling them a stopgap undervalues the WHO position. Third is the caries detector misunderstanding — these dyes stain the affected zone too and over-stain, so they guide, not dictate, excavation depth. Finally, the molecular logic of chemomechanical gels gets asked: papain is a proteolytic enzyme degrading partially degraded collagen in infected dentine while sparing sound cross-linked collagen — that sentence is the whole answer.
Frequently asked questions
How does selective caries removal differ from stepwise excavation?
Selective removal leaves firm affected dentine over the pulp permanently, while stepwise excavation seals retained dentine temporarily and re-enters months later for final excavation.
What material defines the atraumatic restorative technique?
High-viscosity (condensable) glass ionomer cement placed with hand excavation, without rotary instruments — chosen for fluoride release, chemical bonding and moisture tolerance.
What are the drawbacks of silver diamine fluoride?
Permanent black staining of arrested lesions, an initial metallic taste, and the need for repeated application — plus it does not restore cavitated form.
What is the active principle of Papacarie?
Papain, a proteolytic enzyme that degrades the denatured collagen of infected dentine while leaving sound collagen intact, enabling gentle selective removal.
What is a preventive resin restoration?
A small confined composite restoration of a carious pit or fissure combined with sealant placement over the remaining susceptible fissures in the same visit.