HomeMaestro during 3/4 crown preparation on premolar, bur used to add retentive grooves is.. Tapered fissure publisher :NIL NAM -June 30, 2017 during 3/4 crown preparation on premolar, bur used to add retentive grooves is: a. radial fissure b. Tapered fissure.*** Labels Maestro Facebook Twitter Share:during 3/4 crown preparation on premolar, bur used to add retentive grooves is.. Tapered fissure Facebook Twitter WhatsApp Pinterest LinkedIn Reddit Tumblr Telegram Email