Table 1.

Characteristics of included studies

Author	Purpose	Methods	Patients	Interventions and number of patients treated per group	Results	Sites and funding
1. M. Y. M. Shoukheba et al. (2014)	To evaluate the effect of subgingival application of ozonated olive oil gel as an adjunct to SRP in aggressive periodontitis	Randomized controlled clinical trial, 6-month duration	Thirty patients with localized aggressive periodontitis (21 females and 9 males) whose ages ranged from 21 to 30 years were selected	Group I (control group): 15 patients received oral hygiene instructions and SRP of all teeth Group II (test group): 15 patients received oral hygiene instructions, SRP of all teeth in addition to subgingival application of an ozonated olive oil gel (Oxaktiv gel)	Changes in PI, GI, BOP, probing depth, and CAL at 6 months	Patients were selected from Periodontology Department Clinic, Faculty of Dentistry, Tanta University
2. Gianluca Sacco et al. (2016)	To evaluate the clinical and microbiological effectiveness of local oxygen-ozone therapy in the treatment of patients with chronic periodontal disease	Randomized clinical trial, 6-month duration	113 patients aged over 30 years, with CP	Case group: 56 patients (25 males, 31 females) received mechanical therapy + local oxygen-ozone therapy Control group: 57 patients (17 males and 40 females) received MPT alone	Significant reduction in probing depth and BOP	The study was conducted at the Institute of Clinical Dentistry at the University of Sassari, Italy
3. Durga Kshitish and Vandana K Laxman (2010)	To evaluate and compare the effects of oral irrigation with ozonated water and 0.2% chlorhexidine on clinical parameters such as PI, GI, and Gingival Bleeding Index	Randomized, double-blind, crossover, split-mouth design, 18-day duration	Sixteen patients suffering from generalized CP and aggressive periodontitis, aged 20-60 years	The study period of 18 days was divided into two time intervals, i.e., baseline (0 day) to the 7th day, with a washout period of 4 days followed by a second time interval of 7 days	Reduction in PI, GI, and bleeding index was observed	University based
4. Selcuk Yilmaz et al. (2013)	To evaluate the clinical and microbiological results of treatment with Er:YAG laser and topical gaseous ozone application as adjuncts to initial periodontal therapy in CP patients	Randomized controlled clinical trial, 3-month duration	Thirty systemically healthy CP patients between 37 and 67 years of age	Group 1: An adjunctive disinfection procedure was applied with an Er:YAG laser after SRP Group 2: Topical gaseous O3 was applied twice a week for 2 weeks after SRP Group 3: Only the initial periodontal therapy was performed, without any adjunctive procedure	Reduction in PD and RAL was observed	University based and supported by the Department of Periodontology, Faculty of Dentistry, Yeditepe University
5. Skurska A et al.	To compare the clinical status and salivary MMP levels after SRP alone or with ozonotherapy in patients with aggressive and CP	Randomized controlled clinical study, 2-month duration	Fifty-two generally healthy controls with CP or aggressive periodontitis (35 women and 17 men), aged 25-68 years	Group CP-S: 12 patients with CP (10 women and 2 men), aged 43-66 years, underwent SRP procedure Group CP-O: 25 patients with CP (18 women and 7 men), aged 39-68 years, underwent SRP in combination with ozonotherapy Group AP: 15 patients with aggressive periodontitis (7 women and 8 men), aged 25-44 years, underwent SRP in combination with ozonotherapy Control group (C): 14 generally healthy controls (10 women and 4 men), aged 41-80 years, with no periodontal lesions	Significant reduction in PI, approximal PI, BOP, PPD, Sulcular Bleeding Index, and clinical attachment loss was observed	University based and supported by the institutional ethical committee
6. R Al Habashneh, W. Alsalman, Y. Khader (2014)	To determine the clinical and biological effects of the adjunctive use of ozone in nonsurgical periodontal treatment	A randomized controlled clinical trial, 3-month duration	Forty-one patients with CP, aged 23-65 years	Group 1 (control group): 21 patients received nonsurgical treatment in addition to irrigation of pockets with distilled water Group 2 (test group): twenty patients received nonsurgical treatment in addition to irrigation of pockets with ozonated water	Significant reduction in PPD, BOP, and clinical attachment loss was observed	University based supported by Dental Teaching Center at Jordan University of Science and Technology for treatment and follow-up
7. Sae Hayakumo et al. (2013)	To evaluate the clinical and microbiological effects of NBW3 irrigation as an adjunct to subgingival debridement for periodontal treatment	Single-center, placebo-controlled, randomized trial, 2-month duration	Twenty-two healthy, nonsmoking controls, 6 females and 16 males aged 26-72 years	The patients in this study were subjected to one of the two treatment protocols: full-mouth mechanical debridement with tap water in a single visit (WATER) or full-mouth mechanical debridement with NBW3 in a single visit (NBW3)	Significant reduction in PPD, CAL, and BOP was observed	University based supported by the Ethics Committee of Tokyo Medical and Dental University, Tokyo, Japan (#234), and all patients signed a written informed consent form

SRP: Scaling and root planing; CP: Chronic periodontitis; BOP: Bleeding on probing; PPD: Probing pocket depth; GI: Gingival Index; CAL: Clinical attachment level; MPT: Mechanical periodontal therapy; Er:YAG: Erbium: yttrium-aluminum-garnet; RAL: Relative attachment level; PD: Pocket depth; PI: Plaque Index; MMP: Matrix Metalloproteinase