Apical Flap Repositioning vs. Mucosa Excision With Free Gingival Grafts for Peri-Implant Keratinized Mucosa Augmentation

The goal of this clinical trial is to learn which surgical technique works better to increase the amount of firm gum tissue (called keratinized mucosa) around dental implants in adults. The main question it aims to answer is: -Does repositioning the gum flap upward with stitches lead to a greater gain in firm gum tissue width at 6 months compared to simply removing the extra gum tissue, when both techniques are combined with a free gum graft? Researchers will compare two techniques used during the second stage of implant surgery to see which one produces a greater gain in firm gum tissue around the implant. Participants will: * Receive a free gum graft (a small piece of tissue taken from the roof of the mouth) placed around their dental implant during a routine surgical visit * Be randomly assigned to one of the two surgical techniques * Have digital scans of their mouth taken at 5 timepoints over 6 months * Complete a pain diary and answer questions about their experience during the first week after surgery * Attend follow-up visits at 6 weeks, 3 months, and 6 months after surgery