Many clinical studies in periodontics compare a new antimicrobial (mouthwash/chip/gel/subgingival irrigation/etc) which could be allopathic/ayurvedic/herbal. These new agents have a positive group, mostly chlorhexidine and one negative control group (either placebo or only SRP without any adjunctive agent. Is it justifiable to use a negative control when previous studies have proven that adjunctive use of Chlorhexidine is better than only SRP or placebo. When we know that adjunctive use of a gold standard is available that will give additional benefit to the patient, is it ethical to include only SRP or placebo group?
Cant we compare only two groups: test agent against gold standard?
The control group received routine antenatal care while the intervention group had ... for a disease which is known to have negative fetal and maternal outcomes? ... If there is a known effective treatment, the study cannot ethically be done,
