Aloe Vera and Tea Tree Oil Mouthwashes as Effective as Chlorhexidine Mouthwash in Reducing Plaque and Gingivitis in Schoolchildren

Dental plaque can lead to dental caries and gingivitis. Streptococcus mutans is a common microorganism that causes dental plaque. Improper tooth-brushing techniques used by some children are inadequate in removing plaque. In children, mouthwashes could help prevent plaque formation and could be an alternative to chlorhexidine and triclosan mouthwashes, which are associated with adverse effects, such as teeth staining and altered taste. Aloe vera (Aloe vera, Asphodelaceae) and tea tree (Melaleuca alternifolia, Myrtaceae) oil have reported antibacterial and antifungal effects, and have been used for oral health. These authors conducted a double-blind, placebo-controlled, prospective, interventional study to compare the efficacy of herbal mouthwashes containing 7% aloe vera and 0.2% tea tree oil with chlorhexidine mouthwash used by schoolchildren.

The study was conducted at the Department of Paedodontics and Preventive Dentistry at the Manipal College of Dental Sciences in Manipal, India. Schoolchildren aged 8-14 years and enrolled in one of two schools located within 6.2 miles of the study site were eligible for the study. The eligible 152 children were randomly and equally assigned to the following four groups: aloe vera, chlorhexidine, tea tree oil, and placebo. No significant differences in age or gender were observed among the groups.

The aloe vera mouthwash was prepared with 7 g aloe vera, 0.025 g peppermint (Mentha × piperita, Lamiaceae) oil, 0.5 g Tween-80 (Sigma-Aldrich; St. Louis, Missouri), 0.2 g benzyl alcohol, and purified water. Tween-80, or polysorbate 80, is a nonionic surfactant.

The tea tree oil mouthwash contained 0.5 g tea tree oil, 5 g glycerine, 5 g propylene glycol, 2.5 g Tween-80, 0.2g benzyl alcohol, and water. The other two groups used 0.2% chlorhexidine gluconate or distilled water as a mouthwash. The mouthwashes were provided in identical bottles. Each participant was given two bottles containing 300 mL of mouthwash (one to keep at school and one to keep at home).

Each participant was shown how to use the mouthwash twice daily, once after lunch and once after dinner as follows: 10 mL of mouthwash was poured into the bottle lid and then swished in the mouth for 30 seconds before spitting it out. The participants were told not to eat, drink, or rinse their mouth for 30 minutes. Study variables included plaque index, gingival index, and microbiological analysis to determine the salivary S. mutans count. Data were recorded at baseline, after four weeks of mouthwash use, and again after two weeks of not using mouthwash.

In the aloe vera, chlorhexidine, and tea tree oil groups, the mean plaque and gingival scores significantly decreased after four weeks compared with baseline (P<0.001). A marginal improvement in plaque and gingival scores was observed in the placebo group and was attributed to more vigorous and regular mouth washing. The mean S. mutans count significantly decreased in the three treatment groups from baseline to the end of four weeks of mouthwash use (P≤0.001) and from baseline to two weeks after mouthwash discontinuation (P<0.001).

Two weeks after the end of mouthwash use, plaque and gingival scores increased significantly in all groups compared with scores after four weeks of treatment (P≤0.001). Compared with the values at the end of four weeks of treatment, increases in S. mutans counts after two weeks without mouthwash were nonsignificant in the two groups using herbal mouthwashes, but significant in the placebo group (P=0.011). In the chlorhexidine mouthwash group, the S. mutans counts did not increase compared with the other groups, suggesting a greater efficacy of chlorhexidine against the bacteria.

The short duration of this study limited the authors from examining the possible outcomes and potential adverse effects after long-term use of the herbal mouthwashes.

In this study, both herbal mouthwashes were as effective as chlorhexidine mouthwash in reducing plaque and gingivitis; however, chlorhexidine was more effective against S. mutans.

The authors declare no conflicts of interest.


Kamath NP, Tandon S, Nayak R, Naidu S, Anand PS, Kamath YS. The effect of aloe vera and tea tree oil mouthwashes on the oral health of school children… Eur Arch Paediatr Dent. February 2020;21(1):61-66. DOI: 10.1007/s40368-019-00445-5.