Survival and Success of 3D-Printed Versus Milled Immediate Provisional Full-Arch Restorations: A Retrospective Analysis.

Objective: To evaluate and compare the survival rates of 3D-printed and chairside milled resin polymethylmethacrylate (PMMA) immediate temporary provisional full-arch implant restorations using prosthetic survival as the primary outcome.

Materials and methods: Records of 335 routine patients receiving 443 temporary six-implant retained maxillary or mandibular prosthetic restorations between January 2019 and January 2022 at a private clinic (Dr Sobczak Clinical Centre, Radosc, Poland) were considered for this retrospective analysis. The analysis compared prosthetic and implant failure rates between printed and milled restorations as primary and secondary outcomes, respectively. Patient-related and treatment-related characteristics between groups were compared using the Chi-square test and Mann-Whitney U-test, respectively. Group-specific cumulative prosthetic survival was qualitatively and quantitively compared using Kaplan-Meier, generalized linear mixed models and univariate cox proportional hazard analyses. Prosthetic survival was set into context to implant survival using Chi-square tests. A multivariable cox proportional hazards model with frailty was used to identify confounding factors affecting prosthetic survival.

Results: Prosthetic failure rates of milled and printed temporary restorations were 13.01% and 11.25% over the average follow-up period of 307.7 ± 115.5 days, respectively. The corresponding 180-day cumulative prosthetic survival rates were 92.4% and 93%. Hazard ratios for the prosthetic failure of milled and printed restorations did not show a statistical difference (p = 0.794). Implant failure rates in restorations that experienced prosthetic failure (17.31%) were higher compared to restorations without failures (5.63%), with a 3.2 times significantly higher odds of failure for a prosthesis experiencing implant loss (p = 0.003). Gender, presence of teeth at treatment baseline, smoking, and bone augmentation were identified as confounding factors impacting prosthetic survival.

Conclusion: Chairside 3D-printed restorations may represent an equivalent treatment modality to established chairside milled restorations for immediate full-arch therapy. Provisional prosthetic survival may impact implant survival and treatment success.