Cold Plasma and Early Microbial Colonization of Healing Abutments

This prospective split-mouth clinical study will evaluate the effects of different plasma systems on the early microbiological colonization of implant healing abutments after implant surgery. Written informed consent will be obtained from all volunteers prior to participation. Before implant placement, all patients will be instructed to rinse with 0.2% chlorhexidine for 1 minute. Surgery will be performed under local anesthesia using articaine containing 1:100,000 epinephrine. Full-thickness flaps will be elevated, and implant-site osteotomies will be prepared under saline irrigation in accordance with the manufacturer's protocols. In all patients, four implants will be placed during the same surgical session. After completion of the osteotomies for all four implants, each implant site will be assigned, using the sealed-envelope method, to one of the following conditions: control, vacuum plasma, argon jet plasma, or cold atmospheric plasma. The corresponding healing abutment will then be placed, and the wound margins will be primarily sutured. The intervention arms will be defined as control, vacuum plasma, argon jet plasma, and cold atmospheric plasma, and these operational group labels will be used in all statistical analyses. In all groups, titanium Medentika healing abutments measuring 4.5 mm in diameter and 6 mm in length will be used; no pretreatment will be applied in the control group. In the cold atmospheric plasma group, plasma will be applied for 60 seconds using the piezobrush® PZ3 device manufactured by relyon plasma GmbH (Germany), with ambient air as the working gas (electrical connection: 110-240 V/50-60 Hz; maximum power consumption: 18 W). The nozzle-to-surface distance will be standardized at 5 mm, and the application angle will be kept perpendicular. In the argon jet plasma group, the same piezobrush® PZ3 device will be used with the Multigas Module and argon gas; a flow rate of 11 L/min will be provided via the regulator, and the application t