Closed vs open curettage — a comparison of methods for treating advanced periodontitis

A patient with periodontitis hears in the clinic: "curettage is needed". One clinic says "closed will be enough". Another — "open is better". The price difference can be significant. This article explains, on the basis of current evidence and clinical guidelines, when each method is justified.

Closed vs open curettage — a comparison of methods for treating advanced periodontitis

What is curettage and why is it needed at all?

Curettage is a procedure involving the cleaning of the root surface of a tooth from subgingival calculus and bacterial plaque. The aim is to remove the bacterial biofilm from the root surface, halt the destruction of the periodontium (the tissues supporting the tooth in bone) and create conditions for healing.

In a healthy periodontium the gap between the tooth and the gum is shallow (1–3 mm) and easy to keep clean with daily hygiene. In periodontitis the gap deepens to form a "pocket" — a space into which calculus and bacteria migrate beyond the reach of a toothbrush and dental floss.

Currently the European guidelines use the term "subgingival instrumentation" instead of the older "curettage", but the concept remains the same. In simple terms: the periodontist cleans areas that the patient cannot reach on their own.

Closed curettage — what it looks like

Closed curettage (in modern EFP nomenclature: subgingival instrumentation) is a non-invasive procedure. The periodontist works with thin curettes and ultrasonic instruments inserted into the pocket through the natural gingival crevice, without cutting or reflecting the gum.

The advantages of closed curettage are significant. Firstly — minimal invasiveness. No sutures, no tissue reflection, no surgical healing phase. The patient experiences only mild tenderness after the anaesthesia wears off, and normal hygiene can usually be resumed the following day.

The limitations mainly concern pocket depth. Closed curettage is most effective for pockets up to 4–5 mm. Beyond this limit the periodontist works "blind" — the instrument reaches the root surface but the clinician cannot see what they are cleaning.

Open curettage — when is it worth considering?

Open curettage (also known as "open flap debridement" or "access flap") involves surgically reflecting the gum away from the tooth. The periodontist incises the gum, reflects the flap and gains direct visual and instrumental access to the root surface and the bone defect.

The advantage of open curettage is direct visual assessment of the root surface. The operator can see what they are cleaning — enabling more thorough removal of calculus from difficult areas, such as furcations (the space between roots of multi-rooted teeth).

The costs are tangible: a longer procedure, a higher fee, poorer post-operative comfort (swelling, sutures, hygiene restrictions for 1–2 weeks), and a longer healing period.

Decision table: when closed, when open

The decision should not be marketing-driven ("we do open because it is better") or cost-driven ("we'll do closed because it is cheaper"). It should be based on pocket depth, tissue anatomy and the patient's individual response to treatment.

Pocket depthRecommendationsRationale
Up to 4 mmScaling + oral hygiene instructionThe pocket is accessible for daily hygiene after calculus removal
4-5 mmClosed CurettageThe curette reaches effectively; opening does not provide a significant advantage
5-6 mmClosed first, open if no improvementNon-invasive attempt first, reassessment at 6–8 weeks
Over 6 mmConsider open from the outsetLow efficacy of closed; benefit from direct vision
With Class II/III furcation involvementOpenFurcations are virtually impossible to clean with closed technique
Vertical bone lossOpen + possible regenerationOpportunity for bone regeneration with an access flap

Importantly: the current EFP guidelines (Sanz et al. 2020) recommend starting treatment with the least invasive option in most cases of periodontitis. Open curettage is reserved for sites that do not respond to non-surgical treatment or where anatomy demands direct access.

How many visits, what cost, what recovery

Both procedures are usually divided into 2–4 sessions (one quadrant per visit), to give the tissues time to heal and limit the working time under anaesthesia.

ParameterClosed CurettageOpen Flap Curettage
Duration of one session45-90 minutes60-120 minutes
Number of visits2-4 (kwadranty)2-4 (kwadranty)
AnaesthesiaLocalLocal
SzwyNoneYes, removed after 7–14 days
Recovery time (discomfort)1-3 days5-10 days
Hygiene restrictionsNone1–2 weeks of gentle brushing
Relative costLowerHigher (approximately 1.5–2×)

Exact fees depend on the treatment plan and individual conditions — we do not publish price ranges here, as it would be misleading without assessing the patient's condition in person.

What happens after curettage — healing and reassessment

After curettage (whether closed or open) the body begins a healing process that lasts 6–8 weeks. In the first days the gums may be sensitive and slightly swollen — this is a normal tissue response.

The key appointment is the reassessment — standardly 6–8 weeks after completion of curettage. We re-measure pocket depths and bleeding at all sites. The outcomes usually fall into one of three categories:

  • Pockets reduced, no bleeding → we move to the maintenance phase (check-ups every 3–6 months).
  • Some pockets still deep → we consider surgical procedures (open curettage, bone regeneration GTR/GBR).
  • Pockets generally deep despite treatment → reassessment of the diagnosis; we consider microbiological testing and possibly adjunctive antibiotic therapy.

Important: periodontitis treatment does not end with curettage. It is a chronic disease that requires ongoing care (the maintenance phase) — visits every 3–6 months, indefinitely. Without maintenance, pockets will deepen again.

Practical advice for the patient

  • Before the decision, ask for a pocket measurement (a periodontal chart). This is the basis for an honest diagnosis. If a clinic proposes a procedure without this measurement — it is worth seeking a second opinion.
  • Ask about specific depths (e.g. "6 mm at tooth 16") and about why the chosen technique is optimal for those values.
  • Do not agree to "open just in case" without clear justification — it is a more invasive and more expensive procedure and should have a specific indication.
  • After the procedure, prepare for the maintenance phase. It is not optional — it is a necessity. Ask straight away how frequently the check-ups will be.
  • Monitor your own symptoms — if bleeding persists 4–6 weeks after curettage, report it at the reassessment.

The most frequently asked questions from patients

Does curettage hurt?

The procedure is performed under local anaesthesia — the patient does not feel pain during it. After the anaesthesia wears off (2–4 hours) mild discomfort and gum sensitivity appear, usually manageable with standard analgesics (paracetamol, ibuprofen).

Will the teeth become more mobile after curettage?

This is a common concern — "the teeth were held in place by the calculus; we remove the calculus and they'll become loose". There is a grain of truth in this: immediately after the procedure the teeth may feel slightly more mobile. But this is temporary — as the gums heal and reattach to the root, stability improves.

Do I need curettage in all quadrants?

Usually yes — periodontitis is typically not a disease of "one tooth" but of the entire periodontium. There are, however, exceptions: localised cases, particularly in young patients, where only specific teeth may be affected.

Read more:

Sources

Source 1 

Links 

https://pubmed.ncbi.nlm.nih.gov/32383274

https://doi.org/10.1111/jcpe.13290

Sanz M, Herrera D, Kebschull M, Chapple I, Jepsen S, Berglundh T, Sculean A, Tonetti MS; EFP Workshop Participants and Methodological Consultants. „Treatment of stage I–III periodontitis—The EFP S3 level clinical practice guideline.” Journal of Clinical Periodontology. 2020;47(Suppl 22):4–60. 

Source 2 

Links 

https://pubmed.ncbi.nlm.nih.gov/33573801

https://doi.org/10.1016/j.jdent.2020.103562

Opis: West N, Chapple I, Claydon N, D’Aiuto F, Donos N, Ide M, Needleman I, Kebschull M; British Society of Periodontology and Implant Dentistry Guideline Group Participants. „BSP implementation of European S3 – level evidence-based treatment guidelines for stage I-III periodontitis in UK clinical practice.” Journal of Dentistry. 2021;106:103562. 

Source 3

Links 

https://pubmed.ncbi.nlm.nih.gov/34414521

https://doi.org/10.1007/s00784-021-04134-w

Opis: Liu B, Ouyang X, Kang J, Zhou S, Suo C, Xu L, Liu J, Liu W. „Efficacy of periodontal minimally invasive surgery with and without regenerative materials for treatment of intrabony defect: a randomized clinical trial.” Clinical Oral Investigations. 2022;26(2):1613–1623. 

Source 4 

Links 

https://pubmed.ncbi.nlm.nih.gov/31860134

https://doi.org/10.1111/jcpe.13237

Opis: Nibali L, Koidou VP, Nieri M, Barbato L, Pagliaro U, Cairo F. „Regenerative surgery versus access flap for the treatment of intra-bony periodontal defects: A systematic review and meta-analysis.” Journal of Clinical Periodontology. 2020;47(Suppl 22):320–351. 

Source 5 

Links 

https://pubmed.ncbi.nlm.nih.gov/35688447

https://doi.org/10.1111/jcpe.13639

Opis: Herrera D, Sanz M, Kebschull M, Jepsen S, Sculean A, Berglundh T, Papapanou PN, Chapple I, Tonetti MS; EFP Workshop Participants and Methodological Consultant. „Treatment of stage IV periodontitis: The EFP S3 level clinical practice guideline.” Journal of Clinical Periodontology. 2022;49(Suppl 24):4–71. 

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