OBJECTIVES: To assess the effectiveness of school dental screening programmes on overall oral health status and use of dental services.

SEARCH METHODS: Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 4 March 2019), the Cochrane Central Register of Controlled Trials (CENTRAL, the Cochrane Register of Studies, to 4 March 2019), MEDLINE Ovid (1946 to 4 March 2019), and Embase Ovid (15 September 2016 to 4 March 2019). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on language or publication status when searching the electronic databases; however, the search of Embase was restricted to the last six months due to the Cochrane Centralised Search Project to identify all clinical trials and add them to CENTRAL.

SELECTION CRITERIA: We included randomised controlled trials (RCTs) (cluster or parallel) that evaluated school dental screening compared with no intervention or with one type of screening compared with another.

DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane.

MAIN RESULTS: We included seven trials (five were cluster-RCTs) with 20,192 children who were 4 to 15 years of age. Trials assessed follow-up periods of three to eight months. Four trials were conducted in the UK, two were based in India and one in the USA. We assessed two trials to be at low risk of bias, two trials to be at high risk of bias and three trials to be at unclear risk of bias.None of the trials had long-term follow-up to ascertain the lasting effects of school dental screening.None of the trials reported the proportion of children with untreated caries or other oral diseases, cost effectiveness or adverse events.Four trials evaluated traditional screening versus no screening. We performed a meta-analysis for the outcome 'dental attendance' and found an inconclusive result with high heterogeneity. The heterogeneity was found to be, in part, due to study design (three cluster-RCTs and one individual-level RCT). Due to the inconsistency, we downgraded the evidence to 'very low certainty' and are unable to draw conclusions about this comparison.Two cluster-RCTs (both four-arm trials) evaluated criteria-based screening versus no screening and showed a pooled effect estimate of RR 1.07 (95% CI 0.99 to 1.16), suggesting a possible benefit for screening (low-certainty evidence). There was no evidence of a difference when criteria-based screening was compared to traditional screening (RR 1.01, 95% CI 0.94 to 1.08) (very low-certainty evidence).In one trial, a specific (personalised) referral letter was compared to a non-specific one. Results favoured the specific referral letter with an effect estimate of RR 1.39 (95% CI 1.09 to 1.77) for attendance at general dentist services and effect estimate of RR 1.90 (95% CI 1.18 to 3.06) for attendance at specialist orthodontist services (low-certainty evidence).One trial compared screening supplemented with motivation to screening alone. Dental attendance was more likely after screening supplemented with motivation, with an effect estimate of RR 3.08 (95% CI 2.57 to 3.71) (low-certainty evidence).Only one trial reported the proportion of children with treated dental caries. This trial evaluated a post screening referral letter based on the common-sense model of self-regulation (a theoretical framework that explains how people understand and respond to threats to their health), with or without a dental information guide, compared to a standard referral letter. The findings were inconclusive. Due to high risk of bias, indirectness and imprecision, we assessed the evidence as very low certainty.