Laser Periodontal Therapy
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Direct answer
Choose the wavelength and you have chosen the tissue: diode lasers (810-980 nm) absorb in pigment and haemoglobin, making them soft-tissue instruments for gingivectomy, frenectomy, depigmentation and sulcular curettage; Nd:YAG (1064 nm) serves similar soft-tissue roles and anchors the LANAP protocol; Er:YAG (2940 nm), whose wavelength coincides with water's absorption peak and is also absorbed by hydroxyapatite, is the one that safely ablates calculus and bone; and CO2 (10,600 nm) is a shallow, haemostatic soft-tissue tool. Real advantages include haemostasis, reduced need for sutures and anaesthesia in selected procedures, and bactericidal effect; the evidence, however, does not show lasers outperforming conventional scaling, root planing and surgery in attachment gain — professional position statements counsel exactly that restraint. Safety is wavelength-specific eyewear for everyone in the room, plume evacuation, and thermal discipline.
What you must remember
- Wavelength-to-chromophore map: diode 810-980 nm — melanin and haemoglobin (soft tissue); Nd:YAG 1064 nm — pigment and tissue protein (soft tissue); Er:YAG 2940 nm — water and hydroxyapatite (hard tissue plus calculus); Er,Cr:YSGG 2780 nm — similar dual action; CO2 10,600 nm — water (soft tissue, shallow penetration).
- The Er:YAG privilege: its coincidence with the water absorption peak lets it ablate calculus and bone with minimal thermal necrosis — the reason it is the hard-tissue laser of periodontics.
- Soft-tissue indications: gingivectomy and gingival contouring, frenectomy, operculectomy, second-stage implant uncovering, gingival depigmentation, aphthous ulcer palliation, and haemostatic sulcular curettage as an adjunct.
- Subgingival claims and their status: laser curettage and adjunctive sulcular debridement are widely marketed; systematic reviews do not demonstrate superior attachment gain over conventional debridement — the examined answer.
- LANAP: an Nd:YAG-based full-mouth protocol claiming regeneration of attachment; regulatory clearance exists for its procedure code, but current professional appraisal treats evidence of superiority as unproven.
- Thermal discipline: power, pulse settings and dwell time decide char versus clean ablation — the point of a laser cutting cleanly is lost the moment carbonisation coats the wound.
- Safety set: wavelength-matched protective eyewear for patient, operator and assistant; matte instruments to avoid reflection; high-volume suction for the infectious plume; and caution irradiating implant surfaces (overheating and surface damage).
- Practical economics: cost, learning curve and maintenance limit adoption; for most indications, scalpel and rotary instruments remain the reference standard lasers are measured against.
One patient, four procedures, four wavelengths
Walk a single surgical day through the laser cabinet. First, a gummy smile correction in a thick biotype: the diode at 810-980 nm excises and sculpts the excess gingiva with built-in haemostasis and no sutures. Second, a high maxillary frenum: the diode or Nd:YAG releases it bloodlessly, and the patient rinses and leaves. Third, a pigmented anterior gingiva the patient wants lightened: diode ablation of the melanin-bearing basal layer, repeated sessions as repigmentation occurs. Fourth, a furcation-involved molar undergoing access surgery: the Er:YAG, in a mist of water spray, strips subgingival calculus the curettes physically cannot reach through the 0.7 mm entrance, and reshapes small bone ledges without chisel heat. What did not happen that day is equally examinable: no laser was chosen where a scalpel was safer and cheaper for the same result, no attachment was regenerated on the molar beyond what debridement and graft achieved, and every person in the room wore the correct glasses while the plume was sucked away. The craft is matching wavelength to chromophore — and restraint to evidence.
Where the exam frames it
Physics-first matching dominates: wavelength to chromophore, and the corollary that Er:YAG alone among the periodontal lasers handles calculus and bone because of water absorption at 2940 nm. Clinical items ask which laser suits depigmentation, frenectomy or sulcular curettage (diode/Nd:YAG family) versus osseous recontouring (Er:YAG family). Evidence questions are deliberately sceptical: adjunctive laser therapy has not demonstrated superior clinical attachment gain over conventional therapy in systematic appraisal — an answer often phrased against marketing claims. Safety MCQs test wavelength-matched eyewear, plume hazard and thermal injury limits, plus care near implant surfaces.
Frequently asked questions
Why is Er:YAG the laser of choice for calculus and bone?
Its 2940 nm wavelength coincides with water's absorption peak and is also absorbed by hydroxyapatite, ablating hard tissue and calculus with minimal thermal damage.
Which lasers suit gingival depigmentation and frenectomy?
Diode lasers (810-980 nm) and Nd:YAG, whose absorption in pigment and soft tissue enables bloodless excision and ablation.
Does laser therapy improve attachment levels beyond scaling and root planing?
Not according to current systematic reviews and professional position statements; outcomes are comparable, and superiority claims are unsupported.
What safety measures accompany laser use?
Wavelength-specific protective eyewear for everyone present, high-volume plume evacuation, non-reflective instruments, and thermal discipline in power and exposure.
What is LANAP?
A full-mouth Nd:YAG laser protocol claiming periodontal regeneration; it holds regulatory clearance as a procedure, but evidence of superiority over conventional therapy remains unproven.