Antiplaque and antigingivitis effect of lippia sidoides: A double-blind clinical study in humans
Gingivitis is a chronic inflammation of gingival tissues and is one of the most frequent periodontal diseases, affecting more than 90% of the population, regardless of age, sex or race. Brazilian epidemiologic studies show a high prevalence of gingival inflammation, ranging from 74% to 100%, although the individual percentages of gingival bleeding reported by the media vary from 28% to 35%. The clinical signs of this disease are bleeding upon probing, plaque accumulation and pain.
This randomised controlled trial evaluated the antiplaque and antigingivitis effect of lippia sidoides (LS).
Research Ethics Committee (Comitê de Ética em Pesquisa, Coética), University of Fortaleza (UNIFOR). Data of approval: 25/07/2005 (ref: 205/2005)
Randomised, double-blind, placebo-controlled, cross-over study
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
Preparation of experimental gel: The essential oil of LS was extracted by steam distillation. Initially, 1 ml of essential oil was diluted in 9 ml of ethylic alcohol (1:9), preparing a 10% mixture. 50 g of carboxymethylcellulose was added to the LS infusion (1,000 ml) and the mixture was kept boiling until its complete dissolution to obtain the 10% gel concentration. A glycerin/ethanol mixture (50 ml: 50 ml) was added and the solution was vigorously stirred for 15 minutes until gel formation. A very small amount of menthol (flavouring) and conserving agent were added. The control gel had the same formulation except for the LS extract.
Twenty-six healthy volunteers (13 female and 13 male aged 19 to 25 years) were enrolled in this randomised, double-blind, cross-over study. The trial consisted of a pre-experimental phase and 2 experimental phases of 21 days each with a 1-month washout interval between them. To standardise the groups, the participants were submitted to a meticulous evaluation (pre-experimental phase) to score the plaque index (PLI), gingival index (GI) and the bleeding index (BI) of each tooth. All teeth of each subject were polished and flossed by the examiner to eliminate dental plaque remnants. The importance of oral hygiene was strongly reinforced.
Thirty days after the initial phase, the participants were randomly assigned to 2 groups (experimental phase). On day 0 of both experimental periods, PLI, GI and BI were recorded. A personal "kit" containing a toothshield, a tube with 90 g of control or test gel and a commercial dentifrice with no anti-inflammatory properties (Sorriso®) was given to all participants. During each 21-day experimental period, the participants were instructed to apply the gel onto the experimental teeth and leave for at least one minute, 3 times a day. The participants were asked to refrain from brushing the test quadrant, while the other teeth were normally brushed 3 times a day using a commercial dentifrice. In addition to verbal instructions, the participants were given written recommendations to follow at home. On the last day of each period (21st day), the indexes were recorded and the teeth were polished with pumice.
Primary outcome measure
The indexes (plaque index, gingival index and bleeding index) were recorded on the mesiobuccal, buccal, distobuccal, mesiolingual, lingual and distolingual surfaces of the experimental teeth and their mean scores were calculated. Then, mean scores for the 4 experimental teeth in each participant were calculated to determine the mean index score for the individual. Intra-examiner agreement for all indexes was calculated by repeating the measurements in 10 participants. Timepoints of assessment: Baseline and at the end of each of the two 21-day experimental phases.
Secondary outcome measures
Adverse effects, such as abscess, ulcerations and allergic reactions. The patients will be submitted to weekly evaluations for the observation of side effects within a maximum period of 21 days.
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
All subjects (both males and females, aged 19 to 25 years) had at least 20 natural teeth, 4 of which were posterior teeth in the lower left quadrant (experimental teeth)
Target number of participants
Participant exclusion criteria
1. Medical disorders
2. Under antimicrobial therapy
4. Pregnant women
5. Individuals presenting a probing depth >3 mm associated with any mandibular teeth
6. Subjects with retentive factors of dental plaque, such as carious cavity and excess restoration in the test area
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Av. Engo. Leal Lima Verde, 2086
University of Fortaleza (Brazil)
Av. Washington Soares
University of Fortaleza (UNIFOR) (Brazil)
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Not provided at time of registration
Intention to publish date
Participant level data
Not provided at time of registration
Basic results (scientific)