Jaime, LozadaAladdin, Al ArdahJoseph, LeeZhe, ZhongAlajmi, Saud2026-07-112026https://hdl.handle.net/20.500.14154/79497To whom it may concern, I have completed my Master’s degree and have uploaded the official completion letter from the university confirming that I have fulfilled the program requirements. I have also attached my transcript; on page 3, it shows that my thesis was awarded a grade and accepted as part of the Master’s degree requirements. Since the final certificate and official transcript may take up to one month to be issued, the attached university letter and transcript are provided as proof of completion. Sincerely, Dr. Saud AlajmiThe purpose of this in-vitro study was to compare the biodegradation behavior of a commercially available collagen membrane and a 3D-printed polycaprolactone (PCL) scaffold containing 25% β-tricalcium phosphate (β-TCP) when exposed to different degradation environments over a six-month period. Seventy-two specimens were prepared, consisting of collagen membranes and PCL/β-TCP scaffolds. Samples were randomly allocated into four degradation media: phosphate-buffered saline (PBS), simulated body fluid (SBF), trypsin-EDTA, and SBF supplemented with collagenase. Each specimen was incubated at 37°C and retrieved at predetermined intervals ranging from 3 hours to 6 months. Thickness and weight measurements were obtained at every timepoint using a standardized 3D-printed jig and high-precision digital instruments. Scanning electron microscopy was used to evaluate surface morphology and structural changes. Kaplan–Meier survival analysis and statistical comparisons were performed to assess differences in degradation rates between the two test materials and solutions. Collagen exhibited rapid degradation across all conditions, with the fastest breakdown occurring in enzymatic media. Significant reductions in thickness and weight were observed in the early stages, and several collagen samples reached complete degradation within weeks. In contrast, the PCL/β-TCP scaffolds demonstrated slower and more controlled degradation, with thickness and weight remaining stable during the initial phases and gradually decreasing over the study duration. Survival analysis consistently favored PCL/β-TCP, indicating prolonged structural persistence compared with collagen. SEM evaluation revealed early fibrillar disintegration and collapse in collagen samples, whereas PCL/β-TCP maintained its architecture, showing only surface erosion, localized pitting, and exposure of β-TCP particles. Within the limitations of this in-vitro model, collagen membranes showed rapid degradation regardless of the medium, while PCL/β-TCP scaffolds provided sustained structural stability over six months. The findings suggest that PCL/β-TCP scaffolds may serve as a long-lasting, customizable alternative to collagen membranes in guided bone regeneration procedures requiring extended space maintenance.57en-USImplantBone graftGBRPCLThesis