5. Research recommendations based on a gap in the evidence on chlorhexidine treatment for the prevention of dental caries in children and adolescents.

Core elements	Issues to consider	Status of research for this review
Evidence (E)	What is the current state of evidence?	A systematic review that identified eight RCTs matching the eligibility criteria, but were incompletely reported, had significant losses to follow‐up, and were assessed as at unclear or high risk of bias
Population (P)	Diagnosis, disease stage, comorbidity, risk factor, sex, age, ethnic group, specific inclusion or exclusion criteria, clinical setting	Children ± 13 years permanent and primary dentition. High to moderate caries risk History of previous caries experience (MS levels/caries screen assessment) From low‐income (low/no fluoride) and high‐income countries School and community setting EXCLUDED Participants with fixed orthodontic appliances
Intervention (I)	Type, frequency, dose, duration, prognostic factor	Chlorhexidine‐containing products: Gels, toothpastes, varnishes, mouthrinses, chewing gums and sprays of different formulations, concentrations and application regimens Administration minimum once over a period of 1 year EXCLUDED Combined interventions of chlorhexidine and fluoride Compliance to be recorded
Comparison (C)	Type, frequency, dose, duration, prognostic factor	Placebo, no intervention or routine care Head‐to‐head comparisons: different chlorhexidine preparations, concentrations, frequency (single or multiple application) of use EXCLUDED Comparisons between chlorhexidine and fluoride interventions Concomitant topical fluoride administration Compliance to be recorded
Outcome (O)	Which clinical or patient‐related outcomes will the researcher need to measure, improve, influence or accomplish? Which methods of measurement should be used?	Dental caries (coronal) Diagnosis (at the dentine level) clinically/radiographically confirmed. Caries increment: change from baseline (D(M)FS/T, d(m)fs/t) index. MS reductions in levels Pain, quality of life or patient satisfaction outcomes measured on a validated scale
Time Stamp (T)	Date of literature search or recommendation	14 January 2014
Study Type	What is the most appropriate study design to address the proposed question?	RCT Methods: Concealment of allocation sequence 'Clear' Blindness: Patients, carers, trialists, outcome assessors blind Setting for administration: home or dental hospital/clinic Setting for clinical outcome assessment: in dental hospital/clinic with appropriate length of follow‐up

(D(M)FS/T: decayed, missing and filled surfaces or teeth (permanent)
 d(m)fs/t): decayed, missing and filled surfaces or teeth (primary)
 MS: mutans streptococci
 RCT: randomised controlled trial