“…The great majority of studies used titanium implants (32 studies) and only five inserted exclusively zirconia implants(Cionca et al, 2015;Payer et al, 2013;Spies, Kohal, Balmer, Vach, & Jung, 2017;Spies, Pieralli, Vach, & Kohal, 2017;Spies, Stampf, & Kohal, 2015). The great majority of studies used titanium implants (32 studies) and only five inserted exclusively zirconia implants(Cionca et al, 2015;Payer et al, 2013;Spies, Kohal, Balmer, Vach, & Jung, 2017;Spies, Pieralli, Vach, & Kohal, 2017;Spies, Stampf, & Kohal, 2015).…”