## 2 Materials and Methods  
### Study Design and Patients  
The present case-control study was recorded at clinicaltrials.gov with ID number NCT06191510. Every participant enrolled in the study provided written informed consent approved by the School of Dentistry of Ribeirao Preto Research Ethics Committee (protocol 21305419.1.0000.5419). The study followed the Helsinki Declaration principles and STROBE guidelines for manuscript preparation.  
Patients were enrolled in private practice from 2019 to 2022 by an experienced oral surgeon (J.G.F.) (Table 1). The primary criteria for inclusion were molar extraction and an indication of immediate implant placement in a fresh socket with a preserved buccal socket wall. Further inclusion criteria were healthy adults (\(\geq\)18 years old) demonstrating satisfactory plaque control and presence of interradicular septum, with a minimum of 5 mm intraosseous preparation for primary stability. Individuals were excluded if they smoked over 10 cigarettes daily, had uncontrolled systemic diseases or unmanaged metabolic disorders, had a history of chemotherapy or radiation treatment in the oral and maxillofacial region, were pregnant, had taken antibiotics or corticosteroids in the past 3 months, or were on medications that alter bone metabolism, including bisphosphonates. The estimation of the sample size was derived from the literature [18] involving post-extraction sockets after 4 months, using mean and standard deviation values for keratinized tissue. A total of 28 samples (14 per group) was calculated using GPower 3.1, with a significance level of 5%, 80% power, and a mean difference of 1.0 mm between groups. The control and test groups were randomly allocated using the randomization program (randomizer.org). All clinical procedures were performed by the same operator, and another independent blinded operator conducted the analyses (V.F.C.). The primary outcome of the study was the assessment of keratinized mucosa width, while the secondary outcomes included linear measurements of hard and soft tissue, performed on tomographic images in both horizontal and vertical directions.  
\begin{table}
\begin{tabular}{l c c} \hline
**Variable** & **n** & **Mean \(\pm\) SD (Range) Number (\%)** \\ \hline _Patients_ & & \\ Age (years) & 26 & 64.82 \(\pm\) 11.75 (42–86) \\ Gender & 26 & \\ Female & & 14 (53.85) \\ Male & & 12 (46.15) \\ \hline _Implant_ & & \\ \hline Position/Tooth area & 28 & \\ 16 & & 3 (10.71) \\ 17 & & 2 (7.14) \\ 26 & & 7 (25) \\ 27 & & 2 (7.14) \\ 36 & & 2 (7.14) \\ 37 & & 3 (10.71) \\ 46 & & 5 (17.87) \\ 47 & & 3 (10.71) \\ 48 & & 1 (3.58) \\ Type & & \\ Tissue level, SLActive, TiZr & & 28 (100) \\ Implant brand & & 28 (100) \\ Straumann & & 28 (100) \\ Implant Diameter & & 28 (100) \\ Narrow 3.3 RN & & 28 (100) \\ Implant length (mm) & 28 & \\ 8 & & 2 (7.15) \\ 10 & & 17 (60.71) \\ 12 & & 9 (32.14) \\ Implant survival (\%) & 28 & 100\% \\ \hline _Type of biomaterial_ & & \\ \hline B & 14 & \\ Jaw & & 8 (57.14) \\ Upper & & 6 (42.86) \\ BM & 14 & \\ Jaw & & \\ Upper & & 6 (42.86) \\ Lower & & 8 (57.14) \\
**Vertical soft tissue thickness (mm)** & & \\ B & 11 & 2.17 (0.48) \\ BM & 11 & 2.33 (0.48) \\ \hline \end{tabular}
\end{table}
Table 1: Patient and implant characteristics.