Longitudinal Soft Tissue Changes During Periodontal Ligament–Mediated Immediate Implant Placement with the Root-Membrane Technique

Purpose: To assess longitudinal volumetric changes during immediate implant placement with simultaneous intentional retention of the buccal aspect of the root. Materials and Methods: This study assessed 10 cases drawn from a previously reported cohort that had study casts available pretreatment and at least 2 years after periodontal ligament (PDL)–mediated immediate implant placement. Gypsum casts were scanned using a laser scanner and converted into digital three-dimensional rendered files. The digital casts were superimposed, and semi-automated subtractive assessment was performed via specialized software. Results: Data from 10 patients with a minimum of 3 years follow-up (median follow-up time: 42 months) were analyzed. Each person contributed one implant site in this study. All implants successfully maintained osseointegration during the follow-up period and demonstrated optimal soft tissue stability. Changes during the observation period ranged from 0.19 mm (95% confidence interval [95% CI]: 0.10 to 0.28) in the midfacial region 6 mm apical to the mucosal zenith to –0.06 mm (95% CI: –0.14 to 0.02) at 5 mm apical to the base of the distal papilla. All changes were noninferior to pre-extraction baseline measurements based on a 0.5-mm noninferiority margin. Conclusion: The intentional retention of the buccal aspect of the root with its periodontal apparatus during immediate implant placement led to optimal soft tissue dimensional stability in the esthetic zone. This technique holds promise for clinical application, and further controlled clinical studies are warranted to determine the comparative clinical benefit from the use of this procedure. Keywords: flapless procedure, immediate placement, PDL-mediated implant placement, surgical procedure