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The recent development in enhancing the corrosion resistance of materials by covering with powdered layers open the way to use the procedure also for cavitation erosion protection, phenomenon always present in hydraulic machinery runners as well as ship propellers. The present research analyzes the behavior of four different types copper layers, deposited with high velocity flames, HVOF upon specimens realized from cast steel for general use 270-480 W (equivalent with OT500-3 used in Romania), to cavitation erosion in a Laboratory device. Even if the powder density and the layers thickness have close values, the behavior to cavitation erosion is different and depend primarily on the powder chemical composition and the microscopic structure.

This 2-year study illustrated that short implants are a viable option in selected clinical scenarios. Short implants with wider diameters are preferred because they have less marginal implant bone loss.

Different types of internal implant–abutment connections, namely hexagon and conical, have been used for implant restoration. However, data regarding the benefits of these internal connections in terms of clinical outcomes are scarce. Accordingly, the aim of this study was to compare radiographic marginal bone loss (RMBL) and associated implant complications between implants with internal hexagon (IH) connections and those with internal conical (IC) connections. Forty-nine patients with 98 implants (two per patient) placed in the posterior mandible were recruited. All implants were inserted in pairs in solid D2 bone according to a randomized sequence; the first patient received an IH connection implant on the mesial side while the second patient received an IC connection implant on the mesial side. Each patient received one implant with an IH connection and one with an IC connection, placed side-by-side. Four months after placement, all implants were loaded with single screw-retained ceramic restorations with internal hexagon or conical connections. RMBL and complications, including implant/prosthesis failure, were recorded at the time of implant loading (baseline) and 6, 12, and 36 months after loading. The results revealed no significant between-group differences in RMBL (P = .74), gingival bleeding on probing (P = .29), and complications (P = .32). Thus, the type of internal implant–abutment connection did not affect clinical outcomes, including RMBL and implant/prosthesis failure. Future studies should additionally evaluate long-term prosthesis-related complications such as screw loosening and fracture between the two types of internal connections.

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