Table 4.

Summary of included studies on oral irrigators.

Study	Study Design and Evaluation Period	Intervention	Primary Outcome Measures	Outcomes
Cutler et al. [59]	Clinical trial, crossover study, 52 subjects, 2 weeks	Oral irrigator vs. brushing	Probing pocket depth, bleeding on probing, gingival index, plaque index, IL-1β and PGE2 levels	Improvement in all clinical parameters with oral irrigation. A reduction in pro-inflammatory cytokine profile in gingival crevicular fluid
Al-Mubarak et al. [60]	Randomised clinical trial, 52 diabetic subjects with adult periodontitis, 12 weeks	Oral irrigator vs. brushing	Modified gingival index, probing pocket depth, plaque index, clinical attachment level, bleeding on probing, reactive oxygen species generation, cytokines (TNF-α, IL-1β, IL-10, PGE2), and HbA1c	Significant reduction in plaque index, gingival index, bleeding on probing, and reactive oxygen species generation compared to brushing. Significant reduction in IL-1β, and PGE2 from baseline within test group
Newman et al. [68]	Multi-centre randomised clinical trial, 155 subjects receiving supportive periodontal therapy, 6 months	Regular oral hygiene vs. oral irrigation with water vs. oral irrigation with water and zinc sulphate solution	Bacterial measurements, gingival index, bleeding on probing	Oral irrigation with water was superior to regular oral hygiene and additional irrigation with zinc sulphate for reducing gingival inflammation. Oral irrigation with water significantly reduced bleeding on probing compared to regular oral hygiene
Barnes et al. [69]	Randomised clinical trial, 105 subjects, 1 month	Manual toothbrush + floss vs. manual toothbrush + oral irrigator vs. sonic toothbrush + oral irrigator	Bleeding index, gingival index, plaque index	Irrigation groups were more effective in reducing bleeding index and gingival index. The manual toothbrush + floss group was less effective than the sonic toothbrush + irrigation for reducing plaque
Rosema et al. [75]	Randomised home-use experiment, 108 subjects, 1 month	Oral irrigator vs. floss	Bleeding index, plaque index	Oral irrigator is superior to floss in reducing gingival bleeding
Goyal et al. [70]	Randomised clinical trial, 70 subjects, single use	Oral irrigator vs. floss	Plaque index	Oral irrigator as an adjunct is superior to floss as in plaque removal
Husseini et al. [77]	Systematic review, 7 studies, 590 subjects, 2–6 months	Oral irrigators vs. brushing	Plaque index, bleeding index, gingival index, probing pocket depth	Oral irrigators do not have a beneficial effect in reducing visible plaque. However, there is a trend of improving gingival health by reducing bleeding
Goyal et al. [71]	Randomised clinical pilot study, 28 subjects, two weeks	Oral irrigator vs. IDBs	Plaque index, bleeding on probing	Oral irrigators are more effective than IDBs for reducing gingival bleeding. No difference for plaque index
Lyle et al. [73]	Randomised pilot study, 28 subjects, single-use	Oral irrigator vs. IDBs	Plaque index	Oral irrigators as adjuncts remove significantly more plaque than IDBs after a single use
Stauff et al. [67]	Randomised clinical trial, 60 subjects, 4 weeks	Phillips Airfloss (microdroplet device) vs. floss	Papilla bleeding index, modified proximal plaque index, amount of gingival crevicular fluid	Microdroplet device was more effective at reducing plaque, with the added benefit of comfort of use
Goyal et al. [72]	Randomised clinical trial, 69 subjects, 1 month	Waterpik vs. Sonicare Air Floss Pro	Bleeding on probing, modified gingival index, plaque index	Waterpik is significantly more effective than Sonicare in reducing bleeding and gingivitis
Sharma et al. [74]	Randomised clinical trial, 82 subjects, single-use	Waterpik vs. Sonicare Airfloss	Plaque index	Waterpik removes significantly more plaque from tooth surfaces than Sonicare
Magnuson et al. [76]	Randomised clinical trial, 40 implants, 1 month	Oral irrigator vs. floss (around implants)	Bleeding on probing	Oral irrigator demonstrated significantly greater reduction in bleeding than floss