Diode and Er:YAG lasers: how they work, uses and limits
A dental laser is not a treatment in itself: it is an instrument whose effect depends on its wavelength and on the hand that guides it. This page explains how the two lasers used at the Levallois-Perret practice, the diode laser and the Er:YAG laser, work, in which situations Dr Hazout proposes them, what treatment costs and what the studies genuinely allow one to expect from them in treating periodontitis.
Contents8 sections
- A matter of wavelength
- On the gum: procedures where the laser brings real comfort
- In periodontal pockets: an adjunct to debridement, not a substitute
- In which situations Dr Hazout proposes a laser, and which one
- Where the laser fits in periodontitis treatment
- The safety of a dental laser
- The cost of treatment with a laser
- Limits: what the laser does not do
A matter of wavelength
A laser emits light of a single wavelength, concentrated into a beam. What matters is which tissue absorbs that light: where it is absorbed, it turns into heat or mechanical energy; where it is not, it passes through or scatters. Two lasers of different wavelengths therefore have neither the same effects nor the same uses, and results obtained with one cannot be transferred to the other.
| Diode laser | Er:YAG laser | |
|---|---|---|
| Mainly absorbed by | Pigments: haemoglobin in blood, melanin | Water in the tissues |
| Main effect | Heating: cutting and coagulating soft tissue | Surface ablation of soft and hard tissue (bone, calculus) with little heat transfer |
| How it is used | Thin optical fibre, in contact with the tissue | Handpiece with water spray |
The diode laser works through heat: its light, absorbed by pigments in blood and tissue, cuts and coagulates the gum. That same heat, if poorly controlled, can injure the tooth or bone, which calls for great care near roots, bone and implants [2]. The Er:YAG laser (erbium: yttrium-aluminium-garnet) is very strongly absorbed by water: it “vaporises” a thin layer of tissue, including bone or calculus, leaving an altered zone only about 10 to 20 micrometres deep on the root [1]. It works under a water spray that cools the surface.
On the gum: procedures where the laser brings real comfort
The practical value of a dental laser is clearest in soft-tissue surgery. The diode laser cuts while coagulating, which limits bleeding. The procedures concerned are the following:
- Gingivectomy and gum reshaping: removing excess gum, correcting an irregular contour, uncovering a tooth or an implant before a prosthesis.
- Frenectomy (releasing a short lip or tongue frenum): a 2021 systematic review reports less bleeding, often no stitches and less post-operative pain than with a scalpel, based on few and heterogeneous studies [6].
- Haemostasis: stopping local bleeding during or after surgery.
- Small mucosal lesions to be removed, after diagnostic assessment.
The Er:YAG laser can also be used during periodontal surgery to clean the surface of a root or a bone defect [1]. It is then one tool among others, chosen by the operator; no clear clinical superiority over conventional instruments has been established. Laser reshaping of the gum, used to correct a gummy smile, is described on the Gum aesthetics page.
In periodontal pockets: an adjunct to debridement, not a substitute
Lasers are often presented as a way to “disinfect” periodontal pockets, the spaces that deepen between gum and root as periodontitis destroys the attachment. A diode laser can indeed be introduced there through a thin fibre, and an Er:YAG laser can remove calculus and inflamed tissue. The question is therefore not whether the laser acts in the pocket, but whether it adds anything to mechanical root cleaning, root surface debridement (scaling and root planing), which remains the basis of treatment.
The clinical trials assessed for the 2020 European guideline did not show a sufficient benefit when a laser is added to mechanical root cleaning. The European Federation of Periodontology (EFP) suggests not using lasers as an adjunct to subgingival instrumentation [3], drawing in particular on a systematic review that could not demonstrate a consistent advantage, so widely did devices and settings vary between studies [4]. This position does not say the laser is harmful; it says its additional benefit is not established.
Around implants, the 2023 European guideline likewise does not suggest adding a diode laser to professional cleaning for peri-implant mucositis, nor using lasers to treat peri-implantitis, either as an adjunct or on their own [5]. Dr Hazout therefore does not use a laser to “disinfect” an implant; prevention and treatment of peri-implant diseases are explained in the article Gum care around implants.
At the practice, a laser is nonetheless proposed in some pockets, after debridement and never in its place. The patient is told so: it is an adjunct to which studies attribute at most a modest additional benefit, and whose justification rests on specific situations, described below. The detail of the studies, their figures and what remains to be shown are gathered in the article Diode and erbium lasers: what does the evidence say?
In which situations Dr Hazout proposes a laser, and which one
The principle is simple: mechanical cleaning remains the basis of periodontitis treatment; a laser is proposed when it can bring a concrete advantage for a specific procedure. In practice, three situations recur.
- Deep or residual periodontal pockets. During initial treatment, or at re-evaluation if some pockets have not reduced enough, the diode laser may be passed into the pocket after debridement to act on the inflamed gum wall, and the Er:YAG laser to remove residual deposits from the root with little heating. The choice between them depends on pocket depth, root anatomy and the state of the gum.
- Inflamed, thickened gum. When the gum stays swollen despite cleaning, the diode laser allows inflamed tissue to be removed or reshaped with limited bleeding.
- A procedure on the gum: gingivectomy, reshaping, frenectomy, haemostasis, described above. This is where the laser's value is most clearly documented.
Conversely, a laser is not proposed on its own to treat periodontitis, nor to disinfect an implant surface, nor as a substitute for periodontal maintenance, which remains the decisive factor in keeping results stable over time.
Where the laser fits in periodontitis treatment
The laser is not a separate appointment. In some pockets it complements initial periodontal treatment, which is carried out at the practice on the whole mouth, six sextants, in a single visit under local anaesthetic, with ultrasonic tips and curettes; it does not replace this mechanical cleaning. The practical arrangements, the course of treatment and aftercare instructions are explained at the practice, according to your situation. The principle of treatment, from assessment to re-evaluation, is set out on the page How periodontitis is treated.
The sequence below summarises the practice's approach, from root cleaning to the aim of regeneration, with the Er:YAG laser. The aim is new attachment along the root; it depends on the shape of the defect, plaque control and smoking, and is not achieved in every case. Periodontal regeneration has its own page.
The safety of a dental laser
A laser is a powerful instrument whose safety rests on three elements: protective glasses matched to the wavelength, worn by the patient and the team; power and pulse settings chosen for the target tissue; and a controlled working area, signposted during use. The main risk is thermal: a diode laser that is poorly set or held too long in one spot can burn the gum, bone or an implant surface [2]. The Er:YAG laser, cooled by water, transfers little heat, but it removes material and demands the same precision.
The cost of treatment with a laser
Initial periodontal treatment of the whole mouth, all six sextants in a single visit, is charged at €1,440 without laser and €1,800 with diode and Er:YAG lasers. These are overall amounts: they cover the whole mouth and are not broken down by area. The difference reflects the additional time and the use of the equipment; it is discussed before treatment, and the decision to use a laser or not rests with the patient, informed of the modest benefit to be expected. Isolated laser procedures on the gum are quoted individually. These treatments are not reimbursed by French national health insurance; top-up insurance may cover part of the cost depending on the policy. All fees are listed on the Fees page.
Limits: what the laser does not do
It is worth saying clearly, because the dental laser is often presented as a solution in itself. A laser does not cure periodontitis without debridement: the roots must be cleaned mechanically. It does not regrow lost bone; only regenerative surgery, in defects of favourable shape, can rebuild part of it. It does not do away with periodontal maintenance or stopping smoking, which weigh far more on the long-term result than the instrument used in the chair. Finally, the percentages of bacteria destroyed that one sometimes reads come from laboratory measurements or immediate samples: they say nothing about the lasting clinical result, which is what randomised trials measure.
What can reasonably be expected is an adjunct in targeted situations, real comfort for procedures on the gum, and transparency about the state of the evidence. Guidelines evolve with new trials; this page will be updated if their position changes.
Frequently asked questions
Can a laser cure periodontitis without root planing?
No. European guidelines do not propose it either alone or as an adjunct to root cleaning, as no clinical benefit has been demonstrated. At the practice it is used only after debridement, in selected pockets, as an adjunct whose expected benefit is modest.
Diode laser or Er:YAG laser: which one is used?
Both, depending on the procedure. The diode laser, absorbed by pigments, is used on the gum: inflamed tissue in the pocket, gingivectomy, haemostasis. The Er:YAG laser, absorbed by water, removes deposits from the root with little heating. The choice is made for each patient and explained before treatment.
Are lasers dangerous?
Used properly, with eye protection and suitable settings, they are safe. The risks come mainly from excessive heating of tissue, particularly with a diode laser near bone or an implant.
How much does treatment with a laser cost?
Initial periodontal treatment of the whole mouth, six sextants in one visit, costs €1,440 without laser and €1,800 with laser. These are overall amounts, not reimbursed by French national health insurance; details are on the Fees page.
References
- Aoki A, Mizutani K, Taniguchi Y, Lin T, Ohsugi Y, Mikami R, Katagiri S, Meinzer W, Iwata T. Current status of Er:YAG laser in periodontal surgery. Jpn Dent Sci Rev. 2024;60:1-14. DOI
- Al Asmari D, Alenezi A. Laser technology in periodontal treatment: benefits, risks, and future directions—A mini review. J Clin Med. 2025;14(6):1962. DOI
- Sanz M, Herrera D, Kebschull M, et al. Treatment of stage I-III periodontitis-The EFP S3 level clinical practice guideline. J Clin Periodontol. 2020;47 Suppl 22:4-60. PubMed
- Salvi GE, Stähli A, Schmidt JC, Ramseier CA, Sculean A, Walter C. Adjunctive laser or antimicrobial photodynamic therapy to non-surgical mechanical instrumentation in patients with untreated periodontitis: A systematic review and meta-analysis. J Clin Periodontol. 2020;47 Suppl 22:176-198. DOI
- Herrera D, Berglundh T, Schwarz F, Chapple I, Jepsen S, Sculean A, Kebschull M, Papapanou PN, Tonetti MS, Sanz M; EFP workshop participants and methodological consultant. Prevention and treatment of peri-implant diseases-The EFP S3 level clinical practice guideline. J Clin Periodontol. 2023;50 Suppl 26:4-76. DOI
- Lebret C, et al. Perioperative outcomes of frenectomy using laser versus conventional surgery: a systematic review. J Oral Med Oral Surg. 2021;27:36. DOI
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