Little clinical benefit in chronic periodontitis with the addition of hyperbaric oxygen

Clinical bottom line:

1. Little clinical benefit from the addition of hyperbaric oxygen therapy to ultrasonic removal of plaque for patients with chronic moderate to severe periodontitis

2. Some evidence for a slower rate of recolonization with specific bacterial species.

Citation/s:1.Lombardo G, Pardo A, Signoretto C, Signoriello A, Simeoni E, Rovera A, Nocini PF. Hyperbaric oxygen therapy for the treatment of moderate to severe periodontitis: a clinical pilot study. Undersea & Hyperbaric Medicine: Journal of the Undersea and Hyperbaric Medical Society, Inc. 2020 Jan 1;47(4):571-80.
Corr. author's name and fax: Annarita Signoriello – annarita.signoriello@univr.it

Three-part Clinical Question:For patients with moderate to severe periodontitis, does the addition of hyperbaric oxygen therapy to a single ultrasonic debridement session result in any improved outcome or change in microbiology?
Search Terms: Periodontitis; mouth flora; ultrasound

The Study:Single-blinded randomised controlled trial with intention-to-treat.
The Study Patients: Patients with chronic periodontitis and at least 20 teeth where at least one site had a probing pocket depth greater than 6mm and 30% of affected sites more than 5mm.
Control group (N = 10; 10 analysed): Oral hygiene care plan and mechanical removal of supra- and subgingival deposits using full-mouth ultrasonic subgingival debridement.
Experimental group (N = 10; 10 analysed): As above plus 100% oxygen breathing for 90 minutes daily at 2.5ATA for a total of 10 sessions.

The Evidence:


Time to Outcome

Control group

HBO  group

Relative risk reduction

Absolute risk reduction


Bleeding on probing (mm)

3 months






95% CIs:

104% to -100%

-0.204 to 0.408

NNT = 2 to INF

NNH = 5 to INF

Visual plaque index

3 months






95% CIs:

-100% to 284%

-0.26 to 0.36

NNT = 4 to INF; NNH = 3 to INF

Bleeding on probing - qualifying sites only

3 months






95% CIs:

8% to 100%

0.05 to 0.8

1 to 22


Non-Event Outcomes

Time to outcome

Control group

HBOT group


Median (range) clinical attachment level (mm)

3 months

4 (4 to 5)

4 (4 to 5)


Median (range) Patent pocket depth (mm)

3 months

4.5 (3.5 to 6)

5.5 (4 to 6)


1. Good randomisation with allocation concealment. Outcomes were assessed by an assessor blind to allocation. Each individual enrolled contributed multiple sites for analysis.
2. The primary outcome was clinical attachment level (CAL): the distance from the cementum-enamel junction to the base of the sulcus/ pocket.
3. Most outcomes showed little difference between groups and the clinical benefit does not seem great.
4. There was faster bacterial recolonization to three months in the ultrasound only group (p<0.05 – figures not reported). Some differences in favour of the addition of HBOT were observed for individual species.
5. There is an analysis problem in this CAT because each individual contributed multiple sites. However my assessments are similar to those published.

Appraised by:Mike Bennett m.bennett@unsw.edu.au; Thursday, 19 August 2021
Kill or Update By: August 2025