Materials and methods
A 6-month, single-centre, split-mouth, randomised controlled clinical trial was conducted. The National Medical Ethical Committee of the Republic of Slovenia granted ethical approval (No. 0120–595/2018/4). The clinical protocol was also submitted to Clinicaltrials.gov (No. NCT04036513). Before taking part, all subjects were given a description of the proposed treatment and gave their informed and written consent. The study was carried out following the Helsinki Declaration’s principles.