Purpose: To evaluate the soft tissue response in posterior teeth adjacent to interdental single implants comparing intrasulcular and trapezoidal incision, and to study their evolution over time. Materials and Methods: A controlled randomized clinical trial was carried out in the Oral Surgery and Implantology Unit of a University Clinic. All the included patients received an interdental single implant (Frontier 2.45, Ilerimplant; Global Medical Implants). The incision type was randomized by sealed envelopes into two groups using the SPSS statistical package (SPSS): (1) intrasulcular or (2) trapezoidal incision. Probing depth and gingival recession at the mesial and distal teeth adjacent to the implant were measured before implant placement, 1 month after surgery, the day of the abutment connection, and at 6 months and 1 year postloading. Scar formation and papilla index were measured 1 month after surgery, and at 6 months and 1 year postloading. Results: Forty patients with one implant per patient were included: 20 in the intrasulcular and 20 in the trapezoidal group. No statistical differences were found between incision types in the measured parameters (probing depth, recession, and interproximal papilla). When analyzing periodontal changes of the total sample, significant differences were found between implant placement and the 1-year follow-up in recession, scar formation, and papilla index. Conclusion: The incision type used to place a single interdental implant did not significantly influence the periodontal parameters of the adjacent teeth. Considering the whole sample, the values between implant placement and 1 year postloading showed significant differences in recession, scar formation, and papilla index over time. Keywords: dental papilla, gingival recession, incision, mucoperiosteal flap, scar, single-tooth implant