Effects of Ozone Therapy as an Adjuvant in Periodontitis: A Meta-Analysis of 13 Trials (2025)

Background

Scaling and root planing - a professional deep clean below the gumline - is the standard first treatment for periodontitis, but it cannot always clear bacteria from deep or awkward pockets. Many small trials have tested ozone as an add-on, with mixed results. This review set out to pool the randomised evidence and ask whether adding ozone to a deep clean makes a measurable difference.

The authors are Jiaxuan Liu, Yuxiao Huang, Jiaqi Huang, Wanrong Yang and Renchuan Tao of the Department of Periodontics and Oral Medicine, College of Stomatology, Guangxi Medical University, Nanning, China.

Study design

This is a systematic review and meta-analysis of randomised controlled trials published between 2013 and 2023 in which people with chronic periodontitis received scaling and root planing either with ozone or with a placebo or no additional treatment. Thirteen trials met the criteria, with 655 participants in total - 328 in ozone groups and 327 in control groups. Eight trials used ozonated water and five used gaseous ozone. Applications typically lasted 30 to 60 seconds, ranging from a single session to a four-week course, and most trials followed patients for four to six weeks or three months.

The outcomes pooled were probing depth, clinical attachment level, gingival index (gum inflammation), bleeding on probing and plaque index.

Findings

Pocket depth: small but significant benefit. Adding ozone reduced probing depth by an extra 0.26 mm on average (95% confidence interval 0.05 to 0.48 mm, p = 0.01).

Gum inflammation: small but significant benefit. The gingival index fell by an extra 0.15 points (95% confidence interval 0.07 to 0.24, p = 0.0006).

No significant difference on bleeding or plaque. Bleeding on probing (p = 0.23) and plaque index (p = 0.27) did not differ significantly between ozone and control groups.

Gum attachment: borderline. Clinical attachment level favoured ozone but fell just short of significance (p = 0.06).

Routes. Results varied by delivery method: individual trials of ozone gas tended to show benefits for bleeding and attachment, while ozonated water trials tended to show benefits for pocket depth and gum inflammation.

No increase in adverse reactions was found with ozone.

What the authors concluded

The authors conclude that "ozone therapy combined with SRP is superior to SRP alone in improving PD and GI indexes in patients with periodontitis, without increasing adverse reactions".

Limitations of this study

The authors describe the number of included studies as insufficient, the sample sizes as small, and note a risk of bias in some trials - five did not state how they randomised patients, and allocation concealment was unclear in five. They recommend large multi-centre randomised trials.

For readers: the benefits found are real but modest in size - a quarter of a millimetre of pocket depth - and they apply to ozone used alongside a professional deep clean in people with established periodontitis, not to daily home use on its own. The trials also varied widely in how ozone was applied, which makes it hard to say which protocol works best.

Gum disease should be diagnosed and managed with your dentist or hygienist.

Related reading

Ozonated Water Irrigation in Periodontitis: A Randomised Trial of 50 Patients (2025)

Efficacy of Ozone Therapy in Dentistry: A Systematic Review of 11 Trials (2025)

Ozone Gel in Chronic Periodontal Disease

Liu J, Huang Y, Huang J, Yang W, Tao R. Effects of ozone therapy as an adjuvant in the treatment of periodontitis: a systematic review and meta-analysis. BMC Oral Health. 2025;25:335. Published 4 March 2025. doi:10.1186/s12903-025-05639-6