- To find the overall effect of ayurvedic and herbal dentifrices i.e. toothpaste, toothpowder, gel, mouth rinse in patients of gingivitis on dental plaque index, gingival index and bacterial colony counts of debris present over plaque or in saliva.
- To find the effective plant species used in herbal dentifrices against plaque control.
Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines were followed for reporting this systematic review. A detailed protocol was prepared initially and registered in the International Prospective Register of Systematic Review (http://www.crd.york.ac.uk/PROSPERO/) and obtained the registration no:)
Criteria for Considering Studies for this Systematic Review and Meta-analysis:
2.2.1 Participants-Interventions-Comparators-Outcomes-Study design (PICOS) Questions. This systematic review was executed mainly focused on the question i.e. “How are the ayurvedic and herbal dentifrices efficacious in plaque control in teeth and to reduce gingival inflammation and bacterial load in tooth debris?”
Types of studies: Only randomized clinical trials (RCTs) related to the above question were included in this study.
Types of participants: Patients diagnosed as established gingivitis and otherwise having no other dental or systemic disease.
Types of interventions: Any intervention in form of herbal or ayurvedic toothpaste, toothpowder, gel, mouth rinse in form with or without mechanical use of the toothbrush, floss etc. Herbal dentifrice should consist of at least one of its components as the herb. Multiple combinations of plant products were called Herbal and classical or patent ayurvedic formulations were called ayurvedic. Oil pulling therapy i.e. rinsing the mouth with any type of single or poly herbal-based oil or essential oil was considered under Oil pulling therapy.
Type of comparison: Any comparator either a negative placebo, control having chlorhexidine or any other antiseptic compound, and conventional toothpaste or mouth rinse not containing any herbal or botanical component as a constituent was considered.
Types of outcome measures: The clinical effect of intervention or control that was established on the certain parameters of plaque index, gingival index and colony count.
- Plaque index: Standard mean difference (SMD) of QHPI (Quigley and Hein plaque index), TQHPI (Turesky-Gilmore-Glickman modification of Quigley-Hein plaque index) or SLPI (Silness and Löe Index).
- Gingival index: Standard mean difference (SMD) of LSGI (Löe and Silness Gingival Index).
- Colony-forming unit (CFU) Standard mean difference (SMD) of Colony Counts.
Secondary outcomes: Adverse event if any,
2.2.2 Eligibility criteria: Based on the PICOS question, the following inclusion criteria were made to fulfill compulsorily by all the included studies:
- All the participants must be diagnosed case of gingivitis and should not contain any other dental or systemic illness.
- The dentifrice of intervention should be having at least one or more active herbal ingredients, natural or plant extract.
- The dentifrice of the comparison group must be any product that does not have any herbal or plant-based component.
- The above intervention or control should be used by subjects along with the self-performed mechanical oral hygiene measures i.e. toothbrush, finger or any other means.
- The outcome of the study must include plaque index, gingival index or colony count as one of the assessment parameters.
- Randomized clinical trials (RCTs) only will be included.
Exclusion criteria: All the studies, other than RCT i.e. quasi-randomized trial, clinical study, observational study, cohort study, Cross-sectional study, case report, in-vivo, in-vitro study, systematic reviews were excluded.
2.2.3 Search methods for identification of studies
An exhaustive literature search was conducted on online databases like PubMed/Medline, CAM-QUEST®, and the Cochrane Central Register of Controlled Trials in August 2021. Unpublished studies were also looked for in the grey literature. The search was conducted using keywords such as gingivitis, dental plaque, dental plaque index, Ayurvedic, Herbal Medicine, Phytotherapy, Plant Preparations, Plant Oils, and Mouthwashes. Only publications written in English were considered, and there was no time limit on the studied period. For a more comprehensive search of articles, the Boolean operators 'AND' and 'OR' were used. Other relevant articles were found by looking through the references of the retrieved articles.
2.2.4 Selection of studies: Two authors (DJ and AKD) independently checked all of the articles for duplication. For inclusion and exclusion criteria, the title and abstract were carefully scrutinized. The articles' full text was examined and checked for eligibility criteria. If a full-text version of an article was not accessible, the relevant author was contacted to request it. Either the Researchgate website or e-mail was used to make the request. Any article that had a single exclusion term was not considered for further investigation. If there was a disagreement about whether a study should be included or excluded, it was addressed through discussion or by a third reviewer (SA).
2.2.5 Data collection process and data items: All the details of included RCTs were filled in preformed Microsoft Excel Sheet in participant study definition, risk of bias assessment, total length of study, unit of randomization, unit of analysis, participants characteristics, intervention, control, outcome, result and other items systematically by two reviewers. The treatment effect for each study was summarized using mean differences (MD) and standard deviations (±SD). The standardized weighted-mean differences (SMD) were calculated for outcomes (measured by different scales or indices) for each study. Random-effects models were used to calculate a pooled estimate of effect and its 95% confidence intervals (CIs). The corresponding author of the included article was contacted in the event of missing data. Non-reported SDs were calculated from the reported standard errors, confidence intervals, presented for mean differences. Data were analyzed with RevMan 5.4.1 software Cochrane Collaboration and forest plots were generated by using the same.
2.2.6 Assessment of risk of bias in included studies:
The risk of bias assessment of the included studies used the approach recommended by the Cochrane Collaboration’s tool. Two review authors (DJ and AKD) independently and in duplicate analysed all included articles for study design characteristics and internal validity criteria. Within and among studies, assessments were carried out. The first step was to provide a summary of the findings from each of the studies that were included. We included publication details author, year of publication, and study period in the study characteristics. To assess the risk of bias in the included research, the methodological quality of each study was noted.
The risk of bias was then assessed, with each included study receiving a score of low, high, or unclear, as specified in the Cochrane Handbook for Systematic Reviews of Interventions. The tool developed by the Cochrane Collaboration was used to assess the risk of bias. For this objective, the following criteria were evaluated: 1. Randomization methods, 2. Allocation concealment, 3. Blinding of participants and personnel, 4. Blinding of outcome assessment, 5. Incomplete outcome data, 6.Selective reporting, and 7. Other bias.
Each study was assessed independently for the risk of bias. The author and source institution were not masked from the reviewers. Any disagreements were resolved through discussion or adjudication by a third party.
2.2.7 Missing data: Wherever possible, missing data were gathered from authors, and the causes for missing data (attrition rates, such as drop-outs, losses to follow-up, and withdrawals), as well as issues with missing data and imputation methods, were studied and critically evaluated. Missing standard deviations (SD) were imputed (average of SD of studies where reported), and sensitivity analyses were used to investigate the impact of imputation on meta-analyses.
2.2.8 Assessment of heterogeneity: Causes of any significant clinical, methodological, or statistical heterogeneity were explored but the pooled effect estimate in a meta-analysis was still presented. Heterogeneity was identified through visual inspection of the forest plots and by using a standard chi-square test α and the I2 statistic < 75%.
If 5 or more studies were included investigating a particular outcome, funnel plots were used to assess small study effects. Several explanations can be offered for the asymmetry of a funnel plot, including true heterogeneity of effect for trial size, poor methodological design and hence bias.
2.2.9 Synthesis of results:
We used Cochran's Q statistic, a chi-square test, and a cutoff p-value of less than 0.05 to assess the data's heterogeneity. The I2 statistic and forest plots were used to assess the consistency of the results. In comparison to sampling error, the I2 statistic describes the proportion of variation in point estimates related to heterogeneity. For the graphic presentation, forest plots were employed.