Jain S, Sayed M E, Shetty M et al. Physical and Mechanical Properties of 3D-Printed Provisional Crowns and Fixed Dental Prosthesis Resins Compared to CAD/CAM Milled and Conventional Provisional Resins: A Systematic Review and Meta-Analysis. Polymers (Basel) 2022; 14: 2691.

Milled temporary restorations have better colour stability.

Well-fitting provisional crowns and bridges are essential for the success of the definitive restoration. These restorations should maintain tooth position, protect the pulp and periodontal tissues, and be functional and aesthetic particularly when temporisation is needed over a long period, such as in full mouth rehabilitation or implant treatment. Conventional PMMA suffer the disadvantage of high polymerisation shrinkage and retaining residual monomer.

This literature review found 25 previous studies which had compared the physical properties of provisional crown and bridge material produced conventionally, by 3D printing and by milling. Fracture and flexural strength, elastic modulus and wear resistance was found to be better for 3D printed restorations than milled.

Fracture strength, flexural strength, peak stress, elastic modulus and wear resistance were found to be better with 3D printed resins when compared to conventional and CAD/CAM milled provisional materials. Conventionally cured PMMA may contain air bubbles and other inclusions, thus negatively effecting strength. 3D printed restorations may have inferior properties with regards to colour stability.