Damping behavior of implant-supported restorations

Objectives The aim of the present study was to assess the shock absorbing capacity of implant-supported restorations (CAD/CAM composite resin or zirconia abutment with composite resin or porcelain crown/onlay) and a simulated natural tooth complex using the Periometer (R). Material and methods One hundred and twenty Morse taper implants (Titamax CM 11 mm) were mounted on bone-simulating acrylic resin base and restored with CAD/CAM zirconia (60) and metal composite resin Paradigm MZ100 (60) abutments. Using CEREC3, standardized onlays (60) and crowns (60) were designed and milled in ceramic (Paradigm C) or composite resin (Paradigm MZ100) to simulate a maxillary premolar. All restorations were luted with a preheated light curing composite resin (Filtek Z100). Fifteen extracted human upper premolars were mounted with a simulated PDL and used as control group. The Periometer (R), a new handheld percussion probe that measures the energy loss coefficient (LC) for both natural teeth and implant-supported structures, was positioned perpendicularly to the buccal surface of each restoration. Three measurements of the LC were collected for each specimen. The effect of each variable (abutment material, restoration material, and restoration design) on the LC was explored using multiple regression analysis. Results Differences in LC between the abutment material (zirconia/Paradigm MZ100), the restoration material (Paradigm C/Paradigm MZ100) and the restoration design (onlay/crown) were recorded. The average LC of zirconia and metal composite resin abutments ranged from 0.040 to 0.053 and 0.059 to 0.068, respectively. Zirconia abutments restored with composite resin restorations (LC 0.051-0.053) had the closest LC value when compared with teeth with simulated PDL (0.049). Conclusion Composite resin onlays/crowns bonded to zirconia implant abutments presented similar dynamic response to load (damping behavior) when compared to teeth with a simulated PDL.