This randomized controlled trial aimed to evaluate the impact of early versus delayed change of abutment on bone levels, soft tissue, and patient satisfaction with single-tooth immediate implants. In 26 patients, flapless immediate implants were placed in the anterior maxillary region (13-23). Postoperatively, all patients received a resin abutment with an emergence profile identical to that of the extracted tooth and were provided with a provisional resin crown. Based on the provisional abutment, a custom digital copy abutment made of zirconium with a titanium adapter was manufactured. The patients were randomized into two groups: the test group received the definitive zirconia abutment after 4 days, while the control group had the abutment changed after 3 months. In both groups, the definitive ceramic crowns were inserted 3 months post-surgery. The primary study outcome was the marginal bone level after 1 year, with peri-implant soft tissue (PES/Pink Esthetic Score) and oral-health-related quality of life (OHIP/Oral Health Impact Profile) defined as secondary parameters. No statistically significant differences for initial bone level remodeling or later bone loss were found between both groups after 1 year. Two prosthetic complications (one per group) required abutment replacement, but no implant failures occurred. Mean marginal bone levels were 0.71 ± 0.95 mm (mesial: 0.55 ± 0.97 mm, distal: 0.86 ± 1.07 mm) in the test group and 0.22 ± 0.93 mm (mesial: 0.15 ± 1.10 mm, distal: 0.30 ± 0.89 mm) in the control group. The Pink Esthetic Score (PES) was 11.9 ± 1.6 in the test group and 10.62 ± 2.87 in the control group (p = 0.39), showing no significant difference in esthetic outcomes. The Oral Health Impact Profile (OHIP) score at 6 months was also not statistically significant for both groups. In immediate implants in the anterior maxilla, the timing of definitive zirconia abutment placement (4 days versus after 3 months) did not result in any statistically significant differences in peri-implant bone level, peri-implant esthetics, or patient-related quality of life.
Pohl et al. (Mon,) studied this question.