Load-Bearing Capacity of Fiber-Reinforced Composite Abutments and One-Piece Implants.

Fiber-reinforced composites (FRC) can potentially help in a physiologic stress transmission due to its excellent biomechanical matching with living tissues. Novel one-piece FRC implants and abutments with two different fiber orientations were loaded until failure to assess the load-bearing capacity, fracture patterns, and precision of fit. The one-piece FRC implants showed significantly higher load-bearing capacity compared to FRC abutments regardless of the fiber orientation (p < 0.001). For FRC abutments, bidirectional abutments showed significantly higher loads compared to unidirectional abutments (p < 0.001). The type of structure and fiber orientation are strong determinant factors of the load-bearing capacity of FRC implants and abutments.

Useful surface parameters for biomaterial discrimination.

Topographical features of biomaterials' surfaces are determinant when addressing their application site. Unfortunately up to date there has not been an agreement regarding which surface parameters are more representative in discriminating between materials. Discs (n = 16) of different currently used materials for implant prostheses fabrication, such as cast cobalt-chrome, direct laser metal soldered (DLMS) cobalt-chrome, titanium grade V, zirconia (Y-TZP), E-glass fiber-reinforced composite and polyetheretherketone (PEEK) were manufactured. Nanoscale topographical surface roughness parameters generated by atomic force microscopy (AFM), microscale surface roughness parameters obtained by white light interferometry (WLI) and water angle values obtained by the sessile-water-drop method were analyzed in order to assess which parameter provides the best optimum surface characterization method. Correlations between nanoroughness, microroughness, and hydrophobicity data were performed to achieve the best parameters giving the highest discriminatory power. A subset of six parameters for surface characterization were proposed. AFM and WLI techniques gave complementary information. Wettability did not correlate with any of the nanoroughness parameters while it however showed a weak correlation with microroughness parameters.

Bacterial adhesion efficiency on implant abutments: a comparative study.

The attachment of Escherichia coli ATCC 25922 and Staphylococcus aureus ATCC 28213 onto six different materials used to manufacture dental implant abutments was quantitatively determined after 2 and 24 h of contact between the materials and the bacterial cultures. The materials were topographically characterized and their wettability determined, with both parameters subsequently related to bacterial adhesion. Atomic force microscopy, interferometry, and contact angle measurement were used to characterize the materials' surfaces. The results showed that neither roughness nor nano-roughness greatly influenced bacterial attachment whereas wettability strongly correlated with adhesion. After 2 h the degree of E. coli attachment markedly differed depending on the material whereas similar differences were not observed for S. aureus, which yielded consistently higher counts of adhered cells. Nevertheless, after 24 h the adhesion of the two species to the different test materials no longer significantly differed, although on all surfaces the numbers of finally adhered E. coli were higher than those of S. aureus.