Maintenance work on the ZORA databases is scheduled for Wednesday 22 May 2019 from 20:00-22:00. During this period ZORA and JDB will not be available. Thank you for your understanding.
Eichenberger, M; Erb, J; Zwahlen, M; Schätzle, M (2015). The timing of extraction of non-restorable first permanent molars: a systematic review. European Journal of Paediatric Dentistry, 16(4):272-278.