Objectives
A systematic review of randomised and non-randomised controlled trials was conducted to evaluate studies of the effectiveness of different tooth replacement strategies in adult patients with shortened dental arches. The objectives of the review were to determine the survival rates of different prosthodontic interventions, the risk of tooth loss with and without prosthodontic interventions, and the impact of different tooth replacement strategies on oral-health related quality of life (OHRQoL).

Methods
The protocol was registered with the International Prospective Register of Systematic Reviews (PROSPERO CRD42017064851), and the review was conducted in accordance with the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA).

Results
The search strategy identified 112 potentially relevant publications; 22 from Medline (OVID), 54 from EMBASE (OVID), 35 from CENTRAL, one from the authors’ knowledge of the subject area, and none from OpenSIGLE. Ten articles were included in this systematic review. Of these, four were analyses of different outcomes from a multicentre randomized controlled trial in Germany, whilst one study was the pilot phase for this trial. Two further randomized controlled trials were included from the United Kingdom and Republic of Ireland. The remaining articles were reports of prospective cohort studies from Denmark and the Netherlands.

Conclusions
there is currently insufficient evidence to recommend one tooth replacement strategy over another in adult patients with reduced dentitions.

Clinical significance
There is a need for further research as there are insufficient numbers of good quality randomised controlled trials currently available. Authors should be encouraged to adhere to CONSORT guidelines for randomized controlled trials, and report findings in such a way that facilitates future meta-analysis.