Received: 23 July 2019
Accepted: 8 November 2019
First Online: 30 November 2019
Compliance with ethical standards
: The authors declare that they have no conflict of interest.
: The study was approved by the Ethics Committees of the School of Dental Medicine, University of Zagreb, (approval no. 05-PA-30-IV-2/2019) and the University Hospital for Infectious Diseases “Dr Fran Mihaljević”, Zagreb, Croatia (approval No. 01–397–2-2019). All procedures were conducted in accordance with the recommendations of the Declaration of Helsinki.
: Not applicable in the present study.