Impact of Transepithelial Abutment Connection and Disconnection in Dental Implants

Over the past decade, implant research has focused on maintaining the health and stability of peri-implant tissues. A key factor is platform switching at the bone level, where a narrower abutment than the implant is used. This technique increases the implant's horizontal surface area for biological width establishment and reduces stress on the crestal bone. Studies showed that repeated disconnection and reconnection of prosthetic components could compromise the mucosal barrier around implants, leading to an apical shift in the connective tissue junction and vertical tissue loss. This led to the "one abutment, one time" protocol, advocating the placement of the definitive abutment during initial implant surgery to avoid its removal during healing. A recent meta-analysis indicated bone loss at the marginal level due to abutment connection and disconnection, despite different treatment protocols. Thus, a standardized abutment between the fixed prosthesis and the implant has been recommended to preserve marginal bone levels. This approach moves the biological width apically, protecting the bone from irritation and improving marginal bone isolation. However, comparative evidence between direct implant-connected prostheses and trans-epithelial abutments is lacking. This study aims to evaluate the "one abutment, one time" protocol's effect on bone loss 12 months after prosthesis placement. Secondary objectives include assessing patient satisfaction using Patient-Reported Outcome Measures (PROM) during prosthesis fabrication and placement, and obtaining information on the diversity and function of microorganisms on the implant using metagenomic techniques 12 months post-prosthesis placement. Throughout the prosthesis fabrication and the first 12 months, various evaluations will be conducted in both abutment and Ti-base groups: * \*\*Bleeding:\*\* Recorded during various prosthetic stages. * \*\*Pain:\*\* Assessed using a visual analog scale after each stage. * \*\*Anesthesia:\*\* Recorded if used at each stage. * \*\*Radiographs:\*\* Number taken to check the fit. * \*\*Time:\*\* Measured for each prosthetic phase. * \*\*Repetitions:\*\* Number of repeated procedures quantified. * \*\*Metagenomic tests:\*\* Samples collected following the Human Microbiome Project protocol to analyze microbial diversity and function.