Effect of Adjunctive Use of Commercial Daily Mouthwashes on Periodontal Health: An Umbrella Review

ABSTRACT

Background and Aim

Effective oral hygiene using different mechanical means is mainly dependent on the patient. Mouthwashes containing antimicrobial agents have been developed to be used as an adjunct to mechanical supragingival plaque control. The aim of this umbrella review is to evaluate and compare the long‐term efficacy of commonly used, commercially available daily mouthwashes in plaque control and gingival inflammation.

Methods

The current umbrella review was conducted in accordance with the Cochrane Handbook for Systematic Reviews of Interventions using the PICOS format. The search was conducted in four databases: PubMed, Scopus, Cochrane and Web of Science. Nine systematic reviews/meta‐analyses (SRs/MAs) on the long‐term efficacy of commercially available mouthwashes (low‐concentration chlorhexidine [CHX], cetylpyridinium chloride [CPC], mouthwashes with essential oils [EOs], fluoride and oxygen‐releasing mouthwashes) were included.

Results

The results revealed that in all SRs/MAs, the prolonged daily use of mouthwashes helped in reducing plaque and gingival inflammation indices but not always with statistical significance.

Conclusions

Results of the present study indicate that the long‐term use of mouthwashes containing EOs seems to give the best results in both reducing plaque levels and improving gingivitis indices among all tested formulations.

Trial Registration: PROSPERO Registration Number CRD 42024618552

1. Introduction

Oral hygiene using a combination of mechanical means is considered sufficient to remove the microbial dental biofilm and preserve gingival health (Sanz et al. 2020). The effectiveness of these aids depends upon the patient's dexterity, commitment and motivation, and therefore daily homecare in plaque control is often inadequate (Barouch et al. 2019). To overcome such limitations, mouthwashes containing antimicrobial agents have been developed. They are used only as a supplement to mechanical supragingival plaque control because, even though they are easy to use and effective at reducing the numbers of bacteria in their planktonic state, the characteristics of the bacterial biofilm limit their effectiveness as a monotherapy (Masadeh et al. 2013).

The active agents of mouthwashes are either chemical products such as chlorhexidine (CHX), cetylpyridinium chloride (CPC), hydrogen peroxide, hexetidine and others (James et al. 2017; Oo et al. 2023; Hossainian et al. 2011; Afennich et al. 2011; Hassandarvish et al. 2020), or herbal extract derivatives. Eucalyptol, menthol, peppermint, methyl salicylate, clove oil and thymol are some of the essential oils (EOs) associated with well‐known over‐the‐counter mouthwashes (Charugundla et al. 2015). In addition, natural products with antiseptic properties (tea tree oil, aloe vera) are useful as mouthwashes (Zhang et al. 2024; Al‐Maweri et al. 2020). Finally, extracts from curcumin, Salvadora persica, mastic, and so on, also constitute agents of mouthwashes, but are consumed mainly by the local communities where they are produced (Arunachalam et al. 2017; Jassoma et al. 2019; Tsironi et al. 2023).

Mouthwashes are used either during active periodontal therapy (PT) or as part of daily homecare. The use of CHX has been suggested (S3 guidelines) as an adjunct in the treatment of periodontitis stages I–III (Sanz et al. 2020). At high concentrations (≥ 0.12%), its long‐term use (most studies reporting up to 3 weeks since there is no evidence‐based literature on CHX use duration) results in, among others, tooth staining and irritation of the oral mucosa. Therefore, these products are not approved for prolonged use. However, lower CHX concentrations (0.05%/0.06%) along with other antibacterial agents can be used safely daily (James et al. 2017).

Several studies have evaluated the efficacy of these products in reducing plaque levels and in enhancing gingival health with encouraging results. Several systematic reviews (SRs) have been published on the subject, but in many original studies the effects of daily‐use mouthwashes are compared with those of CHX (≥ 0.12%) (Windhorst et al. 2025; James et al. 2017). However, high‐concentration CHX mouthwashes are not recommended for long‐term use, and therefore these comparisons cannot accurately disclose the actual benefit of daily mouthwashes.

An increasing tendency for mouthwash use by the general population for the prevention or treatment of gingivitis and periodontal disease (PD) has been observed. Taking into consideration that in the latest EFP guidelines it is unclear whether everyday use of commercially available mouthwashes can benefit patients with no PD or patients during supportive PT (the role of antiseptics in active PT or in supportive PT was not directly addressed in the SR of the European Workshop that led to the guidelines, while it is stated that adjunctive antiseptics, specifically CHX mouthwashes, may be considered for a limited period), a critical appraisal of the available data was deemed necessary.

Therefore, the aim of this umbrella review was to evaluate and compare the long‐term efficacy of commonly used and commercially available daily mouthwashes in plaque control and gingival inflammation when used as an adjunct to mechanical plaque removal.

2. Methods

2.1. Review Registration (Prospero) Design

The current umbrella review was conducted in accordance with the Cochrane Handbook for Systematic Reviews of Interventions (Cumpston et al. 2019) and registered with an international prospective register of SRs and meta‐analyses (MAs) (PROSPERO) (Registration Number CRD 42024618552 14 December 2024).

2.2. PICOS

The review refers to adult individuals not currently under PT (Population), who are using commercially, and as widely available, over‐the‐counter daily homecare mouthwash (Intervention), compared to a placebo mouthwash and not a positive control such as CHX 0.12% (Comparative). Plaque index (PI) and gingival index (GI) or bleeding index (BI, modified BI) were assessed (Outcome). Only SRs/MAs including randomised controlled clinical trials (RCTs) were evaluated (Table 1).

TABLE 1.

PICO of included studies.

Study no.	Studies	Participants	Intervention	Comparison	Outcome
21	Araujo et al. (2015)	Generally healthy men and women, 18 years or older, with mild to moderate levels of gingival inflammation and dental plaque but without signs of clinical periodontitis	EO‐containing mouthrinse	Daily mechanical plaque control (homecare)	MGI, PI
2	Figuero et al. (2019)	Systemically healthy patients with some degree of gingivitis at baseline	Anti‐plaque products, used adjunctively to mechanical oral hygiene measures with or without previous professional prophylaxis	Positive or negative control adjunctive to mechanical oral hygiene measures	Changes in plaque, gingival or bleeding indices
3	Gunsolley (2006)	Adults 18 years and older (presumed with gingivitis)	Antiplaque and/or anti‐gingivitis agents	Placebo or vehicle control	Anti‐plaque and anti‐gingivitis efficacy
4	Haas et al. (2016)	Systematically healthy participants with gingivitis	EO‐containing mouthrinse as adjuvant to mechanical oral hygiene	Comparison group always comprised a placebo solution, flossing, or CPC as adjuncts to mechanical plaque control	At least one measure of plaque and/or gingivitis
5	Haps et al. (2008)	Adults in good general health (periodontal status not determined)	CPC‐containing mouth rinses as adjuncts to toothbrushing	Toothbrushing only or toothbrushing plus placebo rinse	PI, GI, BI
6	Langa et al. (2021)	Adult individuals (periodontal status not determined)	CPC with manual toothbrushing	Placebo solution with toothbrushing or only toothbrushing	Interproximal plaque or gingivitis indices reductions
7	Van Leeuwen et al. (2014)	Adults with good general health (periodontal status not determined but selected studies included only participants with gingivitis)	EO‐based mouthrinse as an adjunct to self‐performed daily mechanical oral hygiene	Water‐based control or vehicle solution from a fixed formula of EO containing between 21.6% and 26.9% hydro‐alcohol	Primary outcomes: plaque and gingivitis scores Secondary outcome: extrinsic tooth staining

Abbreviations: BI, bleeding index; CHX, chlorhexidine; CPC, cetylpyridinium chloride; EO, essential oil; GI, gingival index; MGI, modified bleeding index; PI, plaque index.

2.3. Search Strategy—Inclusion and Exclusion Criteria

The search (Appendix A) was conducted in four databases: PubMed, Scopus, Cochrane CENTRAL and Web of Science. The literature search yielded a total of 3303 articles. After duplicate removal (1174), 2129 records were screened by title and/or abstract by two examiners (Y.A.B., P.A.K.). Of these, 112 articles were considered eligible for full text evaluation with a working team of six experts (W.P., P.A.K., Y.A.B., D.A.A., P.K., C.G.). Any disagreement was discussed within the team. Studies that did not fulfil the inclusion criteria were omitted (Appendix A). Finally, seven studies were included in the umbrella review (Figure 1).

FIGURE 1.

Preferred reporting items for systematic reviews and meta‐analyses (PRISMA) diagram for study selection.

The SRs/MAs had to meet the following inclusion criteria:

1. Include only RCTs.

2. Include only adults.

3. Include individuals with any periodontal diagnosis (gingivitis or periodontitis).

4. Include any commercially available, over‐the‐counter daily mouthwash as comprising the test group.

5. Include only placebo or mechanical oral hygiene as the control group.

6. Include any PI and/or GI as outcome measure.

7. Do not consider any time limit regarding the use of the daily mouthwash.

8. Consider only manuscripts in English language.

SRs and MAs were excluded if the included RCTs:

1. Assessed individuals under non‐surgical or surgical PT.

2. Assessed orthodontic patients or other special populations.

3. Reported any antimicrobial interventions other than adjunctive use of mouthwashes, such as use of dentifrices, gels, sprays, oil pulling, and so on.

4. Reported on non‐commercially available mouthwashes.

5. Used a positive control such as CHX (≥ 0.12%).

6. Assessed peri‐implantitis.

3. Results

The effect of various mouthwashes on plaque control and/or gingival inflammation was evaluated based on seven SRs/MAs. The demographic characteristics of the test subjects are summarised in Table 2. Studies were published between 2006 and 2021 with a follow‐up period of 6 months. Search timeline was from 1980 (Araujo et al. 2015) to 2020 (Langa et al. 2021). One study (Gunsolley 2006) did not report the search duration. Two studies (Araujo et al. 2015; Haas et al. 2016) included data from diverse populations (China, Africa, Tibet, Mongolia, Japan, India, Korea, Iran, Myanmar, USA, Canada, Switzerland), while five did not report on the population studied (Figuero et al. 2019; Gunsolley 2006; Haps et al. 2008; Langa et al. 2021; Van Leeuwen et al. 2014). The sample size varied from 720 participants (Langa et al. 2021) to 5775 (Figuero et al. 2019), with two studies (Gunsolley 2006; Van Leeuwen et al. 2014) not reporting on the population size. All studies included systemically healthy individuals with gingivitis except three (Haps et al. 2008; Langa et al. 2021; Van Leeuwen et al. 2014), which did not report the periodontal status. Intervention and comparator details are given in Table 1. PI and modified BI, mGI were assessed in all studies, while GI was assessed in eight (16, 17, 19–24) and BI in seven studies (16, 19–24).

TABLE 2.

Demographic characteristics of the included studies.

Authors	No. of included RCTs	Total sample size	Country	Sources of search	Duration of search	Follow‐up period
Araujo et al. (2015)	29	5106	USA, Canada	Studies sponsored by Johnson & Johnson Consumer Companies and its predecessors	From 1980 to 2012	6 months or longer
Figuero et al. (2019)	53 (21 for mouth rinses)	8457 (5775 for mouth rinses)	N/R	PubMed CENTRAL	Up to 14 January 2019	6 months or longer
Gunsolley (2006)	50 (at least 25 for mouth rinses)	N/R	N/R	Medline	N/R	6 months or longer
Haas et al. (2016)	14	2597	USA, Canada, Switzerland, Brazil	MEDLINE‐Pubmed, EMBASE, Lilacs, and Scopus	Up to 1 April 2016	6 months or longer
Haps et al. (2008)	8	867	N/R	MEDLINE–PubMed and Cochrane Central Register of Controlled Trials.	Up to and including January 2008	6 weeks to 6 months
Langa et al. (2021)	9	720	N/R	SCOPUS and EMBASE	Up to 26 February 2020	6 weeks to 6 months
Van Leeuwen et al. (2014)	5	N/R	N/R	PubMed‐MEDLINE, Cochrane Central Register of Controlled Trials, and EMBASE	Up to and including September 2013	3 weeks to 6 months

The seven included SRs/MAs assessed data from 62 primary RCTs, which appeared 110 times in the SRs/MAs. The overlap calculated by the ‘corrected covered area’ (CCA) was 12.9%, which is considered high (Pieper et al. 2014).

Of the included studies, one evaluated the effect of low‐concentration CHX (Figuero et al. 2019), four of CPC (Figuero et al. 2019; Gunsolley 2006; Haps et al. 2008; Langa et al. 2021), five of herbal mouthwashes with EOs (Araujo et al. 2015; Figuero et al. 2019; Gunsolley 2006; Haas et al. 2016; Van Leeuwen et al. 2014) and one each of fluoride (Figuero et al. 2019) and oxygen‐releasing mouthwashes (Figuero et al. 2019).

3.1. Quality Assessment (PRISMA, AMSTAR 2 GRADE)

The qualitative and quantitative characteristics of included studies are summarised in Tables 3 and 4, respectively.

TABLE 3.

Qualitative synthesis of the included studies.

Study no.	Study	Methodology for quality assessment	Quality appraisal	Heterogeneity	Findings
1	Araujo et al. (2015)	N/R Risk of bias was evaluated following the Cochrane handbook for systematic reviews of interventions	There was a low risk of performance and detection bias in all 29 studies b/c the study personnel were masked to treatment assignment across all studies This analysis is not subject to publication bias, b/c publication was not considered in the inclusion of studies	Significant heterogeneity among studies (study characteristics examined were supervision, baseline dental prophylaxis, flossing, study period, location). Other sources of heterogeneity: (a) gingival inflammation was assessed in some studies with MGI in others with GI and (b) the number of surfaces evaluated for PI was different among included studies	Clinically significant site‐specific benefit of adjunctive EO treatment in people within a 6‐month period
2	Figuero et al. (2019)	Cochrane Reviewers' Handbook (Higgins and Green 2011)	The evaluation of the risk of bias in individual studies, was made according to the Cochrane list and to the independency of the study. Publication bias was assessed using the Egger test, based on evidence of small‐study effects on p ≤ 0.1	All PMA performed with two or more studies showed high heterogeneity, with I 2 values ranging from 74.6% to 96%.	Mouth rinses containing EEOO_noAlc showed the greatest effect on GI scores, as assessed by NMA
3	Gunsolley (2006)	The inclusion criteria were clearly stated and divided into 7 domains	N/R	Antiplaque effect: the test for heterogeneity was statistically significant for CPC and EOs Anti‐gingivitis effect: significant heterogeneity was present for 0.12% CHX (p = 0.013), EOs (p < 0.001) and CPC (p = 0.004)	The studies in the SR provide strong evidence of the antiplaque, anti‐gingivitis effects of multiple agents and support the use of these agents as part of a typical oral hygiene regimen
4	Haas et al. (2016)	Cochrane Collaboration's tool	Overall analysis of risk of bias suggests that the quality of the studies included in this systematic review ranged from moderate to low. No publication bias was observed	High heterogeneity (I 2 = 97.8%, p < 0.001) was found	EO seems to be superior to placebo + MPC and CPC + MPC for reduction of plaque and gingival inflammation in patients with gingivitis
5	Haps et al. (2008)	Quality was based on following: Method of randomisation and allocation concealment Blindness of examiners Completeness of follow‐up	N/R	Considerable heterogeneity was observed in the interventions, regimens, concentrations of CPC, bio‐availability, outcome, the number, gender and age of participants	CPC containing mouth rinses, when used as adjuncts to either supervised or unsupervised oral hygiene, provide a small but significant additional benefit in reducing plaque accumulation and gingival inflammation
6	Langa et al. (2021)	RoB2 tool by Cochrane	Five studies showed low risk of bias Three studies showed some concern (regarding randomization process and overall risk) One study showed high risk of bias.	High heterogeneity was observed in both analyses for QHPI and GI (I 2 = 89% and I 2 = 98%, respectively)	CPC is efficacious both in plaque and gingival inflammatory parameters, demonstrating the potential to compensate for the limitations of interproximal plaque control
7	Van Leeuwen et al. (2014)	Van der Weijden's checklist	Quality assessment parameters, were based on evaluation of external, internal and statistical validity. Based on these criteria, the estimated risk of bias was low. Publication bias could not be used b/c fewer than 10 studies were included in MA	The majority of MA showed non‐important heterogeneity (I 2 value: 0%–9%)	EOMW appears to provide a significant oral health benefit during the 6 months of use and have an effect on plaque and gingivitis parameters that extends beyond the V‐Sol. Furthermore, the V‐Sol proved to be no different from WC

Abbreviations: CHX, chlorhexidine; CPC, cetylpyridinium chloride; EO, essential oil; GI, gingival index; MA, meta‐analysis; MGI, modified gingival index; N/R, not reported; NaOCl‐MW, sodium hypochlorite mouthwash; NMA, network meta‐analysis; PI, plaque index; PMA, pairwise meta‐analysis; SR, systematic review; V‐Sol, alcohol vehicle solution; WC, water‐based control.

TABLE 4.

Quantitative synthesis of the included studies.

Study no.	Authors	Meta‐analysis	Statistical analysis	Subgroup analysis	Sensitivity analysis	Significance/Direction
1	Araujo et al. (2015)	Yes	Treatment effect and SE estimates were obtained using a generalised linear model approach for the analysis of healthy sites and plaque free sites. This model was used to estimate the OR and associated SE within each study. The DerSimonian and Laird method was used to generate a pooled overall estimate of OR based on the random effects assumption.	Yes	NA	This meta‐analysis showed that addition of daily rinsing with an EO mouthrinse to mechanical oral hygiene provided statistically significantly greater odds of a cleaner and healthier mouth, 5.0 (95% confidence interval [CI], 3.3–7.5) and 7.8 (95% CI, 5.4–11.2) respectively. The percentage reductions in gingivitis and plaque at 6 months were 6.0 (95% CI: 11.3–20.7) and 27.7 (95% CI: 22.4–32.9), respectively
2	Figuero et al. (2019)	Yes	Results were combined using SMDs along with 95% CI. PMAs using a random‐effects model were performed. NMA was conducted to simultaneously compare the different active ingredients and placebo control for each delivery format. The NMA was performed using multivariate random‐effects meta‐analysis. The design‐by‐treatment interaction model was used to evaluate the assumption of consistency in the entire network. The surface under the cumulative ranking curve (SUCRA) was used to potentially rank the treatments	No	Yes. A sensitivity analysis resulted in a significant in‐consistency	The ranking of treatments according to SUCRA results from NMA was the following: EEOO_noAlc, EEOO, (tric_cop), CHX_H, CPC_H, CHX_L, AmF_SnF, CPC_L, alexidine, delmopinol and placebo. Results from NMA were similar to those obtained from PMA in terms of SMD, with all active agents showing greater reductions in GI than placebo control, although in the NMA comparisons, higher SMDs were found for CHX_H and CPC_H compared to PMA results. Statistically significant differences were found between CHX_H, EEOO, EEOO_noAlc and tric_cop versus placebo both in the PMA and in the NMA
3	Gunsolley (2006)	Yes	Standard difference in means and 95% CI were calculated at baseline and at 6 months. A random‐effects model was used to evaluate the overall efficacy of the data, when heterogeneity was present	Yes. Separate analysis of efficacy for each of the active agent was conducted.	N/R	Anti‐plaque effect EOs: All but one study (total of 20 with 25 arms) showed statistical significance. Although the test for heterogeneity was positive, the study results clearly support the anti‐plaque efficacy of the essential oils (Std. Diff. = 0.852, p < 0.0001) CPC: great deal of heterogeneity in both the CPC agents evaluated and the results obtained, with some of the agents exhibiting antiplaque effects and some not exhibiting these effects Anti‐gingivitis effect EOs: The results of one‐ half of the studies were statistically significant for each agent, but all of the studies demonstrated anti‐gingivitis effects. CPC: difficult to reach conclusion due to heterogeneity. Use of MGI will improve researchers' ability to show differences between active and placebo agents
4	Haas et al. (2016)	Yes	Means and SDs at 6mo of each trial group (with and without EO) were used to estimate the WMD and its 95% CI. RETD was estimated for comparisons between EO + MPC and placebo + MPC regarding the QHI and the MGI, and a WMD was estimated and reported. Linear meta‐ analysis was applied. Heterogeneity was assessed by the Q test and quantified with the I 2 statistic. Random effects models were applied using the DerSimonian and Laird method because of high heterogeneity across studies. Pooled WMD were investigated using linear meta‐regression when the number of included studies was more than 10 and heterogeneity was higher than 40%.	Yes	NA	Mouthwashes containing EOs should be considered the first choice for daily use as adjuvants to self‐performed MPC MAs comparing EO and placebo solution: All studies demonstrated statistically significant differences in favour of EO for Q‐H, but with high heterogeneity (I 2 = 97.8%, p < 0.001) and for all gingivitis indices. MA comparing EO and CPC: Statistically lower levels of plaque and gingivitis. The respective WMD values for Q‐H and MGI were −0.75 and −0.52. MA comparing EO, placebo and flossing in the proximal area: EO had a significantly higher decrease in the Q‐H index (WMD = −0.95, 95% CI –1.26 to −0.63; I 2 = 96.0% p < 0.001) and in MGI (WMD = −0.34, 95% CI –0.53 to −0.15; I 2 = 98.9% p = 0.001) compared to placebo in the proximal area. When EO was compared to brushing and flossing regarding levels of plaque in the interproximal area, there was significantly lower levels in favour of EO but there was no significant difference regarding gingivitis. Meta‐regression: High heterogeneity (I 2 > 95%) was found and explained (MGI—R 2 = 63.6%; QHI—R 2 = 80.1%) by differences between studies in the percentage of males, supervision of the mouthwashes and provision of oral hygiene
5	Haps et al. (2008)	Yes	Mean values and standard deviations were obtained by data extraction	Yes	NA	In all cases, baseline scores were not statistically different. The end scores showed a significant effect for the QHPI in favour of the CPC group compared to those of toothbrushing only or toothbrushing followed by a placebo rinse (weighted mean difference [WMD]:0.50, p < 0.00001; test for heterogeneity p = 0.002, I 2 = 71.6%). The heterogeneity was greater for intermediate‐length studies (I 2 = 68.1%) than long‐term studies (I 2 = 58.8%). The end scores also displayed a significant effect for the GI in favour of the CPC group compared to toothbrushing only or toothbrushing followed by a control rinse group (WMD: 0.25, p < 0.00003; test for heterogeneity p = 0.0001, I 2 = 87.0%).
6	Langa et al. (2021)	Yes	Two meta‐analyses were performed for the Turesky modification of the QHPI and the Löe and Silness GI. For both analyses, the MD between baseline and 6 weeks were calculated using a random‐effect model	Yes. Subgroup analyses were created for both meta‐analyses because of different concentrations of CPC used and because of different follow‐up periods using the same indices	NA	The meta‐analysis demonstrated that groups that used CPC displayed a significantly greater reduction in the plaque index score (MD; 95% confidence interval [95% CI]: −0.70; −0.83 to –0.57) and in the gingival index (MD; 95% CI: −0.38; −0.47 to –0.28) when compared to placebo
7	Van Leeuwen et al. (2014)	Yes	DIFFMs were calculated with Review Manager3 using a random‐effect model or a fixed‐effect model In case there are < 4 studies included Heterogeneity was tested by chi‐squared test and the I 2 statistic. A Chi‐squared test resulting in a p < 0.1 was considered an indication of significant statistical heterogeneity	No.	No. Sensitivity analysis could not be conducted because of the limited number of included studies.	The 6‐month brushing studies that evaluated QH modified by Turesky showed a significant effect in favour of the EOMW when compared to the V‐Sol, with a difference in means of 0.39 [95% CI = (0.30; 0.47), p < 0.00001]. A significant effect was also found in favour of the EOMW for GI with a DIFFM of 0.36 [95% CI = (0.26; 0.62), p = 0.0001], and MGI with a DIFFM of 0.17 [95% CI = (0.08; 0.25), p < 0.001]. When the V‐Sol was compared to WC, no significant difference was found for either the plaque scores or the gingivitis reduction, DIFFM = 0.04 [95% CI = (0.09; 0.18), p = 0.51] and DIFFM = 0.03 [95% CI = (0.06; 0.13), p = 0.51], respectively

Abbreviations: alexi, alexidine; AmF_SnF, amine and stannous fluoride; BI, bleeding index; CI, confidence interval; CPC, cetylpyridinium; delmo, delmopinol; DIFFMs, differences of means; EEOO, essential oils; H, high concentration; L, low concentration; MGI, modified gingival index; MPC, mechanical plaque control; NA, not applicable; NMA, network meta‐analysis; QHPI, Quigley‐Hein Plaque Index; RETD, relative end‐of‐trial difference; SMD, standardized mean difference; tric_cop, triclosan copolymer; WMD, weighted mean difference.

Three studies (Araujo et al. 2015; Langa et al. 2021, Van Leeuwen et al. 2014) reported a low risk of bias (RoB) and one (Haas et al. 2016) moderate to low, while two (Gunsolley 2006; Haps et al. 2008) did not report the RoB. Regarding heterogeneity, all studies (Araujo et al. 2015; Figuero et al. 2019; Gunsolley 2006; Haas et al. 2016; Haps et al. 2008; Langa et al. 2021) reported significant or high heterogeneity (I ² value ranging from 74.6% to 98% depending on the study) except one (Van Leeuwen et al. 2014) which found non‐important heterogeneity (I ² value: 0%–9%).

MA was performed on all selected studies. Regarding statistical analyses, six studies (Araujo et al. 2015; Figuero et al. 2019; Gunsolley 2006; Haas et al. 2016; Langa et al. 2021; Van Leeuwen et al. 2014) applied a random‐effects model; one (Araujo et al. 2015) used the generalised linear model approach to determine the odds ratio (OR); and one (Haps et al. 2008) reported outcomes as mean values with standard deviations (SDs).

Regarding quality appraisal of the selected studies, the AMSTAR 2 tool was used (Shea et al. 2017). All seven SRs/MAs had a defined PICO and included RCTs only. No SR/MA was registered apart from Araujo et al. All SRs/MAs, except for Gunsolley, used a comprehensive literature search and performed both study selection and data extraction in duplicate. Only Figuero et al. provided a full list, whereas Araujo et al. gave a partial list of the excluded studies with justification for the exclusions. All seven SRs/MAs described the included studies in detail. RoB was assessed fully in all SRs/MAs but only partially in Gunsolley. Except Araujo et al., no other SR/MA reported on the sources of funding of the included studies. All authors used appropriate methods for statistical combination of results. Except for Gunsolley's study, which did not assess but only partially accounted for RoB of the selected studies, all other SRs/MAs partially did so and assessed the RoB in the interpretation of results. All SRs/MAs provided an explanation for the heterogeneity observed in the studies. Apart from Gunsolley et al. and Haps et al., all other SRs/MAs reported on publication bias. Finally, all SRs/MAs reported on conflicts of interest. Taking into consideration the above, which are the answers to the 16 questions of the AMSTAR 2 instrument (Shea et al. 2017), Araujo et al. had a ‘high’ confidence rating, Figuero et al. ‘moderate to high’, Haas et al., Langa et al. and Van Leeuwen et al. ‘moderate’, Haps et al. ‘low to moderate’ and Gunsolley ‘low’ (Figure 2).

FIGURE 2.

AMSTAR 2 (a measurement tool to assess systematic reviews) tool of the included studies. NA, not applicable; YES: YES; NO: NO; PAR: PARTIAL YES. AMSTAR 2 items (Shea et al. 2017).

The certainty of evidence was assessed by the GRADE system. Under GRADE, all RCTs start as ‘high’ quality of evidence, and can be downgraded considering factors such as study design, RoB, inconsistency, indirectness, imprecision and publication bias. This systematic approach ensures a comprehensive evaluation of the evidence base (Guyatt et al. 2011). Regarding the RoB for the selected studies, those by Araujo et al., Figuero et al. and Van Leeuwen et al. have been assessed as having a low RoB since they only included RCTs that provided information on allocation concealment, blinding and completeness of outcome data, and they were not downgraded in the GRADE system. The remaining four studies were downgraded. The study by Langa et al. included RCTs that did not report properly on their randomisation sequence both for plaque and bleeding indices. Haas et al. had all RCTs but they were funded by the industry and most of them provided unclear information for random sequence generation while only four provided clear information regarding allocation. Overall, the quality of the studies included in this SR ranged from moderate to low. In Haps et al., all studies but one were RCTs. Allocation concealment reporting is absent or unclear in all the studies but two. Finally, Gunsolley's is an older study with poor reporting for both randomisation and allocation concealment, while many of the included studies are industry sponsored. With all the above GRADE (Guyatt et al. 2011) factors considered, Araujo et al., Figuero et al. and Van Leeuwen et al. were categorised as ‘high’, Gunsolley as ‘moderate’ and Haas et al., Haps et al. and Langa et al. as ‘low’ in the assessment (Figure 3).

FIGURE 3.

GRADE (grading of recommendations assessment, development, and evaluation) tool of the included studies.

3.2. Effect of Mouthwashes Containing Low‐Concentration CHX (< 0.10%)

The efficacy of the daily use of low‐concentration CHX (< 0.10%) on gingival health was assessed only in one SR/MA (Figuero et al. 2019). A reduction, although not statistically significant, in GI was reported; however, the data were derived only from a single RCT including 33 participants.

3.3. Effect of Mouthwashes Containing CPC

Four SRs/MAs (Figuero et al. 2019; Gunsolley 2006; Haps et al. 2008; Langa et al. 2021) evaluated the effect of CPC‐containing mouthwashes on gingival health. Figuero et al. analysed the effect of CPC based on its concentration. In four RCTs (429 participants), CPC concentration was ≤ 0.05% (CPC_L), while in three RCTs (292 participants) the concentration was > 0.05% (CPC_H). In all RCTs, CPC reduced the GI but failed to reach statistical significance.

The effect of CPC was also assessed by Haps et al. (six RCTs). The end scores of the MA showed a significant effect on the Quigley and Hein PI (QH‐PI) in favour of the CPC group compared to toothbrushing alone or toothbrushing followed by a placebo rinse (weighted mean difference [WMD] 0.50, p < 0.00001). However, high heterogeneity was observed among the RCTs (I ² = 71.6%, p = 0.002). Likewise, the end scores also showed a significant effect on the GI in favour of the CPC group (WMD 0.25, p < 0.00003), although, again, the heterogeneity among the RCTs was high (I ² = 87.0%, p = 0.0001).

Similarly, the MA by Langa et al. (nine RCTs) showed that, compared to placebo, CPC displayed a significantly greater reduction both in PI (mean difference [MD] −0.70; 95% CI [−0.83 to −0.57]) and GI (MD −0.38; 95% CI [−0.47 to −0.28]). However, high heterogeneity was observed in both analyses (I ² = 89% and 98%, respectively). The indices used were the Turesky modification of QH‐PI and Löe and Silness GI.

Finally, in the efficacy analysis performed by Gunsolley, four out of seven RCTs showed a statistically significant improvement in GI for the CPC group. According to the author, it was difficult to reach a solid conclusion regarding CPC efficacy due to the heterogeneity among the RCTs, with some agents exhibiting anti‐plaque effects while others did not. Specifically, the mouthwashes evaluated were not comparable because the concentration of CPC used varied significantly (0.045%–0.07%), and some mouthwashes had an alcohol vehicle while others did not.

3.4. Effect of Mouthwashes Containing EOs

Herbal mouthwashes containing EOs are the most studied commercially available mouthrinses for daily use. Haas et al. performed a MA and meta‐regression of 14 and 11 RCTs to evaluate changes in QH‐PI and MGI, respectively. The reductions in plaque and gingival inflammation were 32% and 24% higher in the EO groups compared to placebo. Among the two groups, WMD for the QH‐PI was 0.95 (95% CI: 1.26–0.63, p < 0.001) and for MGI 0.3495 (95% CI: 0.53–0.15, p = 0.001). However, the authors reported high heterogeneity (I ² > 95%) among the included RCTs, possibly due to differences in the percentage of males, supervision in the use of the mouthwashes and provision of oral hygiene. Nevertheless, the RoB of the selected studies ranged from moderate to low. These results are in accordance with those by Van Leeuwen et al. Their MA of four RCTs showed that mouthwashes containing EO provided significantly better plaque control and reduction of gingival inflammation compared to an alcohol‐based solution V‐Sol. The difference of means in plaque scores was 0.39 (p < 0.00001), while in gingival inflammation it was 0.36 (p = 0.00001) (Löe and Silness Index). The reported RoB was considered low.

The study by Araujo et al. (32 RCTs, 5106 participants) compared the effect of EO‐containing mouthwashes versus mechanical plaque control. A statistically significant reduction in PI and gingivitis was found at 6 months in favour of the EO group. Responder analyses using aggregate individual‐level data showed that 36.9% and 44.8% of the participants using additionally an EO‐containing mouthwash achieved at least 50% plaque‐free and healthy sites, respectively. In subjects performing only mechanical plaque control, the percentage was 5.5% and 14.4%, respectively. RoB was assessed as low.

Gunsolley reported that in 20 RCTs that evaluated mouthwashes containing different EOs only, one failed to show a statistically significant difference in plaque control in favour of EO. Although the heterogeneity among the studies was high, the authors supported the anti‐plaque efficacy of EO‐based mouthwashes (SD 0.852, p < 0.0001). Regarding gingivitis, 13 of the 17 RCTs revealed statistically significant anti‐gingivitis properties of EOs compared to control agents. Again, although there was significant heterogeneity (p < 0.0001) among studies, all favoured the EO group over the control mouthwash group (Std. Diff. 0.762).

Finally, Figuero et al. (2019) stratified the RCTs evaluating the effect of EOs on gingival inflammation in two groups. The first group (11 RCTs, 1009 participants) had an alcoholic solution of EO and the second group (one RCT, 107 subjects) had a non‐alcoholic solution of EO. In both EO groups, GI improved, but not significantly.

3.5. Effect of Mouthwashes Containing Fluoride or H₂O₂

The effect of sodium fluoride (NaF) and thiocyanate/carbamide peroxide (SCN_H₂O₂) mouthwashes on gingival health was assessed in one SR and MA (Figuero et al. 2019). For both antimicrobial agents, there was only a non‐significant benefit in reducing the GI. These results were derived from three RCTs (732 participants) and one RCT (140 participants) for NaF and SCN_H₂O₂, respectively.

3.6. Comparison of the Effect of Different Mouthwashes on Gingival Health

Only the SR/MA by Figuero et al. tried to rank the different types of mouthwashes according to their efficacy in improving plaque control and/or gingival inflammation. In their network MA (NMA), the ranking of treatments according to SUCRA results from best to worst was as follows: EO in no‐alcohol solution, EO, high‐concentration CPC, low‐concentration CHX, AmF_SnF, low‐concentration CPC, alexidine, delmopinol and placebo. Results from NMA and MA were similar in terms of standardised mean differences (SMD), with all active agents showing greater reductions in GI than placebo control, although in the NMA comparisons, higher SMDs were found for high‐concentration CPC compared to MA results. Statistically significant differences were found between EO and EO in no‐alcohol solution versus placebo both in MA and NMA.

4. DISCUSION

The EFP in its recent clinical guidelines regarding the treatment of periodontitis stage I–III states that ‘the basis of the management of gingival inflammation is self‐performed mechanical removal of biofilm although, adjunctive measures, including antiseptic mouth rinses, may be considered in specific cases, as part of a personalized treatment approach’ (Sanz et al. 2020). Mouthwashes containing CHX 0.12% and 0.20% are considered the gold standard in enhancing gingival health (James et al. 2017). However, the use of these products for a prolonged period is not recommended because of their side effects (James et al. 2017).

Another point of concern about mouthwashes is the emerging evidence regarding their potential effect on blood pressure (BP) regulation. Mouthwashes, through their antimicrobial action, alter the oral cavity's microbial composition, and this affects the nitrate–nitrite–nitric oxide pathway (enterosalivary pathway) which is vital to BP regulation (Duncan et al. 1995; Senkus and Crowe‐White 2020). Related human studies are scarce, and even though they demonstrate a negative effect of mouthwash use (Bondonno et al. 2015; Kapil et al. 2013), the product used in most of the studies is CHX ≥ 0.12%, which is not a mouthwash for everyday use. When various types and strengths of commercially available mouthwashes (including everyday‐use products) were evaluated, results suggested that the stronger mouthwashes (CHX ≥ 0.12%) led to elevated systolic BP after 3–7 days, while mouthwashes containing EO or CPC did not negatively affect any outcome (Woessner et al. 2016).

Therefore, several other mouthwashes that are commercially available have been designed for daily homecare. These products mainly contain chemical antibacterial agents such as CPC or low‐concentration CHX, or are derived from herbal extracts. Although a large body of evidence supports their long‐term use, many studies have compared their efficacy to that of the short‐term‐use gold standard. This may not accurately reflect their contribution to controlling gingival inflammation and thus may underestimate their importance in daily use. Therefore, the purpose of this study was to assess and compare the efficacy of these long‐term‐use daily mouth rinses by evaluating SRs/MAs that examined RCTs where the control group was a placebo mouth rinse.

The present results showed that in all SRs/MAs, prolonged daily use of mouthwashes had a positive effect on plaque control and gingival inflammation. However, this did not reach statistical significance in several studies. The findings indicate that mouthwashes containing EOs gave the best results both in reducing plaque levels and in improving gingivitis indices among the tested formulations. EO‐based mouthwashes were the most studied and exhibited improvement in PI and GI in three studies with statistical significance in both indices and in two with no statistical improvement in GI. Next in efficacy was CPC, which demonstrated an improvement in PI and GI in all four SRs/MAs, which showed statistical significance for PI in all studies (Figuero et al.; Gunsolley; Haps et al.; Langa et al.) but failed to reach statistical significance for GI in two (Figuero et al.; Gunsolley).

Although umbrella reviews are considered to lead to conclusions, the results from the current study need to be interpreted with caution because of methodological inconsistencies among the RCTs in the SRs/MAs included. Specifically, the RCTs used many different indices for plaque control or gingival inflammation, which limits direct comparisons. Even in cases where these indices were similar as they derive from one another (i.e., Silness & Löe 1964 PI, and Simplified Silness & Löe, PI), data still required statistical manipulations/conversions to enter an MA. Indeed, a high inconsistency was observed in most MAs, which weakened the final conclusions of the individual SR. Another issue is that, although in total the included SRs examined the effect of a large number of different antimicrobial agents in mouthwashes, some of these products were severely under represented in the current analysis. Hence, from the nine SRs included, the majority evaluated mouthwashes containing EO or CPC (five and four studies, respectively), while low‐concentration CHX, fluoride and H₂O₂ were assessed only by one SR, which included a small number of RCTs. Therefore, the available body of evidence is not sufficient to accurately estimate the effect of all the mouthwashes studied and safely rank their efficacy. One should always bear in mind that mouthwashes may not be of much value in those subjects with periodontal health or low risk for caries. One should take into consideration the potential risks of allergic reactions, the dysbiosis of the oral microbiota, the emergence of antimicrobial resistance, deleterious effects on the environment related to the wide use of mouthwashes (Brookes, McCullough, et al. 2023) and the possible negative effect on BP. Regarding dysbiosis and antimicrobial resistance, little is known about the effects of mouthwashes on fungi and viruses in the oral microbiome (virome) in vivo, despite the existing in vitro evidence that they ‘kill’ certain viral pathogens Furthermore, there is growing concern that the use of mouthwashes may lead to antimicrobial resistance, and this should be further considered in the context of their widespread use by clinicians and patients (Brookes, Teoh, et al. 2023).

Another limitation of the present study is the use of studies only in English language. Finally, there was no uniformity in the RoB reported, although for most RCTs it was estimated to be moderate to low.

5. Conclusion

In conclusion, all SRs/MAs demonstrated that the additional use of mouthwashes to daily toothbrushing improved both plaque control and gingival inflammation to varying degrees. This may not have been statistically significant every time, but there still remains a positive effect for all formulations tested.

The data derived from this umbrella review demonstrate that the long‐term daily use (up to 6 months) of mouthwashes containing EOs or CPC may enhance gingival health when they are used as an adjunct to mechanical plaque control. However, one cannot ignore the presence of critical methodological limitations of the RCTs, which may question the strength of the available evidence. Therefore, studies with a sound methodology, low RoB and a larger population are needed in order to evaluate safely the additional benefit that these mouthrinses may bring in everyday oral care.

Appendix A.

Search Strategy

Database	Search strategy	Hits
PubMed	((mouthwash) OR (“mouth wash”) OR (mouthrinse) OR (“mouth rinse”) OR (gargle) OR (collut*) OR (“mouth solution”) OR (“oral solution”) OR (“oral rinse”) OR (“oral antiseptic”)) AND (systematic OR meta‐analys* OR metanalys*)	1622
Cochrane Central Register of Controlled Trials	((mouthwash) OR (“mouth wash”) OR (mouthrinse) OR (“mouth rinse”) OR (gargle) OR (collut*) OR (“mouth solution”) OR (“oral solution”) OR (“oral rinse”) OR (“oral antiseptic”)) AND (systematic OR meta‐analys* OR metanalys*) in Title Abstract Keyword	100
Cochrane Database of Systematic Reviews	((mouthwash) OR (“mouth wash”) OR (mouthrinse) OR (“mouth rinse”) OR (gargle) OR (collut*) OR (“mouth solution”) OR (“oral solution”) OR (“oral rinse”) OR (“oral antiseptic”)) AND (systematic OR meta‐analys* OR metanalys*) in Title Abstract Keyword	29
Scopus	TITLE‐ABS‐KEY (((mouthwash) OR (“mouth wash”) OR (mouthrinse) OR (“mouth rinse”) OR (gargle) OR (collut*) OR (“mouth solution”) OR (“oral solution”) OR (“oral rinse”) OR (“oral antiseptic”)) AND (systematic OR meta‐analys* OR metanalys*))	827
Web of Science	((mouthwash) OR (“mouth wash”) OR (mouthrinse) OR (“mouth rinse”) OR (gargle) OR (collut*) OR (“mouth solution”) OR (“oral solution”) OR (“oral rinse”) OR (“oral antiseptic”)) AND (systematic OR meta‐analys* OR metanalys*) (Topic) and Preprint Citation Index (Exclude—Database)	725

Excluded Studies and Reasons for Exclusion

Study (main reason)	Reason for exclusion
1. Yong Chen et al. 2013	Non‐commercial formulations
2. Hossainian et al. 2011	Positive control CHX
3. Swaaij et al. 2024	Tests the vehicle for CHX
4. Serrano et al. 2015	Too many formulations
5. Keremi et al. 2020	Positive control
6. Janakiram et al. 2020	Positive control
7. Kairey et al. 2023	Herbal, positive control mixed compounds
8. Amanpour et al. 2023	Too many types of formulation
9. Kumar 2023	No mouthwash
10. Chatzopoulos et al. 2022	During treatment
11. Janakiram et al. 2020	Herbal, positive control, mixed compounds
12. Mathur et al. 2018	Methodological fault
13. Mehta et al. 2018	Toothpaste
14. Dhingra & Vandana 2017	Non‐commercially available positive control
15. Sunayuana Manipal et al. 2016	Short
16. Monica Prasad et al. 2016	Non‐commercially available positive control
17. Tafazoli et al. 2020	Methodological fault
18. Alshehri et al. 2018	Ortho patients
19. Fakheran et al. 2019	Treatment
20. Ingle 2021	Formulations in various forms
21. AlJameel & Almalki 2020	Positive control CHX
22. Jassoma et al. 2019	Positive control
23. Merchant et al. 2022	Active treatment, special population
24. Furquim dos Santos Cardoso et al. 2021	Methodological fault
25. Javed et al. 2023	Methodological fault mixed population
26. Konopka et al. 2015	Polish language
27. Suresh et al. 2021	Toothpaste
28. Terby et al. 2021	Treatment
29. McGrath 2018	Special population
30. Affenich et al. 2010	Not for everyday use Hexetidine
31. Alroudhan et al. 2021	Methodological fault
32. Perez – Nikolas et al. 2023	Out of scope
33. Khijmatgar et al. 2021	Oil pulling
34. Angelilo et al. 2002	Change in formulation (previously with Triclosan)
35. Riley & Lamont 2013	Toothpaste
36. Santi et al. 2019	Mixed comparators
37. Supranoto et al. 2014	Toothpaste gel
38. Svellenti et al. 2024	Perio treatment
39. Tafazoli &Tafazoli 2020	Duplicate
40. James et al. 2017	Low quality; no specific data; few studies; low CHX
41. Matesanz – Perez 2013	Professional appliance
42. Vanstrydonk et al. 2012	Positive control CHX
43. Zaffar & Ullah 2021	Microbiology
44. Zhang et al. 2018a	Spray
45. Zhang et al. 2023	Active treatment
46. Zhang et al. 2018b	Spray
47. Zhou etal 2018	Special population
48. Barboza et al. 2023	Oral Pathology
49. Bunte et al. 2019	No RCT
50. Canullo et al. 2020	Surgical
51. Casarin et al. 2023	Post surgical
52. Cosyn et al. 2005	Gel
53. Grover et al. 2021	No RCT
54. Johannsen et al. 2019	Dentifrice CHX
55. Langa et al. 2022	Not mouthwash
56. Jong et al. 2023	Oil pulling
57. Da Costa 2017	Mechanical therapy
58. Boyle et al. 2014	Faulty methodology
59. Al Maweri et al. 2022	CHX
60. Elkerbout et al. 2019	CHX
61. Gunsolley 2010	Report
62. Housain et al. 2022	Self preparatory
63. Prasad et al. 2016	Too Vague no focused question
64. Halboob et al. 2020	CHX
65. Adam et al. 2023	Herbal Salvadora Persica
66. Paraskevas et al. 2006	Dentifrice
67. Inchingolo et al. 2024	Faulty methodology
68. Alsehri et al. 2018	Ortho and oral pathology patients
69. Shirban et al. 2021	Faulty methodology
70. Berchier et al. 2010	CHX
71. Minervini et al. 2024	CHX
72. Lopez et al. 2019	Oral pathology
73. Addy et al. 2007	Not available
74. Swaaij et al. 2020	CHX
75. Chye et al. 2019	Surgical CHX
76. De Asis et al. 2021	No mouthwash not commercially available
77. De Silva et al. 2016	Out of scope
78. Freires et al. 2012	Treatment non commercially available
79. Garcia et al. 2008	CHX 0.12%
80. Gartenmann et al. 2020	Not commercially available
81. Hendiani et al. 2022	Not commercially available
82. Slot et al. 2008	Commentary
83. Van Strydonck et al. 2012	CHX 0.12%
84. Hwu & Lin 2014	Out of focus
85. Jadhav et al. 2021	Too many formulations, gel
86. Kolahi 2006	Out of focus
87. Lopez Valverde et al. 2021	Treatment
88. Haas et al. 2017	Summary
89. Santi et al. 2019	Not commercially available
90. Solderer et al. 2018	CHX after surgery
91. Serano et al. 2015	Commentary
92. Xhang et al. 2021	After non‐surgical treatment
93. Santi et al. 2021	Not commercially available
94. Cosyn et al. 2005	Gel
95. Stoeken et al. 2007	CHX
96. Housain et al. 2022	Self‐preparation
97. Muniz et al. 2020	Not commercially available
98. Inchingolo et al. 2024	Faulty methodology
99. Berchier et al. 2010	CHX
100. Balouk et al. 2025	Self‐preparatory
101. Bunte et al. 2019	No RCT
102. Escribano et al. 2016	Too many formulations, CHX
103. Keremi et al. 2020	Positive control

Koromantzos, P. A. , Bobetsis Y. A., Giota C., et al. 2026. “Effect of Adjunctive Use of Commercial Daily Mouthwashes on Periodontal Health: An Umbrella Review.” Journal of Clinical Periodontology 53, no. 3: 407–423. 10.1111/jcpe.70061.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.