A comparison of biological marker and prosthodontic complications in splinted and nonsplinted implant-supported prostheses: A split mouth study

Aims: This randomized controlled split-mouth study aimed to compare marginal bone loss (MBL) and peri-implant biological behavior through PICF IL-1β analysis between splinted and nonsplinted implant-supported prostheses restored with the screw and cement-retained prosthesis (SCRP) system. The study design is a randomized controlled trial involving 20 subjects who are considered eligible based on predefined inclusion and exclusion criteria. Materials and Methods: Twenty participants with bilateral posterior edentulism were enrolled. Each received a nonsplinted prosthesis (control group) on one side and a splinted prosthesis (test group) on the contralateral side. Clinical parameters (probing depth, PD; Modified Sulcus Bleeding Index, mSBI), radiographic MBL (marginal bone loss), and PICF IL-1β levels were assessed at baseline, 3 months, and 6 months. After the study was completed, the data were collected, observed, and subjected to statistical analysis using the latest version of SPSS software. Results: Key findings showed statistically significant but clinically modest differences between groups. At 6 months, nonsplinted implants demonstrated significantly higher PD (3.07 ± 0.23 mm vs. 2.83 ± 0.31 mm, P < 0.001), mSBI (1.25 ± 0.55 vs. 0.95 ± 0.60, P = 0.030), IL-1β levels (92.32 ± 8.48 pg/μL vs. 76.59 ± 7.96 pg/μL, P < 0.001), and MBL (0.99 ± 0.11 mm vs. 0.74 ± 0.08 mm, P < 0.001). Prosthodontic complications were more frequent in the nonsplinted group. Conclusions: Splinted SCRPs demonstrated superior clinical performance in maintaining peri-implant tissue stability and minimizing biomechanical complications over 6 months. However, the clinical significance of these differences appears minimal, indicating that both approaches remain viable when proper occlusal management and maintenance protocols are followed.