Assessment of Dental Implants with Modified Calcium-Phosphate Surface in a Multicenter, Prospective, Non-Interventional Study: Results up to 50 Months of Follow-Up

Influence of Topography and Composition of Commercial Titanium Dental Implants on Cell Adhesion of Human Gingiva-Derived Mesenchymal Stem Cells: An In Vitro Study

The topography and composition of dental implant surfaces directly impact mesenchymal cell adhesion, proliferation, and differentiation, crucial aspects of achieving osseointegration. However, cell adhesion to biomaterials is considered a key step that drives cell proliferation and differentiation. The aim of this study was to characterize characterize the topography and composition of commercial titanium dental implants manufactured with different surface treatments (two sandblasted/acid-etched (SLA) (INNO Implants, Busan, Republic of Korea; BioHorizonsTM, Oceanside, CA, USA) and two calcium phosphate (CaP) treated (Biounite®, Berazategui, Argentina; Zimmer Biomet, Inc., Warsaw, IN, USA)) and to investigate their influence on the process of cell adhesion in vitro. A smooth surface implant (Zimmer Biomet, Inc.) was used as a control. For that, high-resolution methodologies such as scanning electron microscopy (SEM), X-ray dispersive spectroscopy (EDX), laser scanning confocal microscopy (LSCM), and atomic force microscopy (AFM) were employed. Protein adsorption and retromolar gingival mesenchymal stem cells (GMSCs) adhesion to the implant surfaces were evaluated after 48 h. The adherent cells were examined by SEM and LSCM for morphologic and quantitative analyses. ANOVA and Tukey tests (α = 0.05) were employed to determine statistical significance. SEM revealed that INNO, BioHorizonsTM, and Zimmer implants have an irregular surface, whereas Biounite® has a regular topography consisting of an ordered pattern. EDX confirmed a calcium and phosphate layer on the Biounite® and Zimmer surfaces, and AFM exhibited different roughness parameters. Protein adsorption and cell adhesion were detected on all the implant surfaces studied. However, the Biounite® implant with CaP and regular topography showed the highest protein adsorption capacity and density of adherent GMSCs. Although the Zimmer implant also had a CaP treatment, protein and cell adhesion levels were lower than those observed with Biounite®. Our findings indicated that the surface regularity of the implants is a more determinant factor in the cell adhesion process than the CaP treatment. A regular, nanostructured, hydrophilic, and moderately rough topography generates a higher protein adsorption capacity and thus promotes more efficient cell adhesion.

Protein adsorption/desorption dynamics on Ca-enriched titanium surfaces: biological implications

Calcium ions are used in the development of biomaterials for the promotion of coagulation, bone regeneration, and implant osseointegration. Upon implantation, the time-dependent release of calcium ions from titanium implant surfaces modifies the physicochemical characteristics at the implant-tissue interface and thus, the biological responses. The aim of this study is to examine how the dynamics of protein adsorption on these surfaces change over time. Titanium discs with and without Ca were incubated with human serum for 2 min, 180 min, and 960 min. The layer of proteins attached to the surface was characterised using nLC-MS/MS. The adsorption kinetics was different between materials, revealing an increased adsorption of proteins associated with coagulation and immune responses prior to Ca release. Implant-blood contact experiments confirmed the strong coagulatory effect for Ca surfaces. We employed primary human alveolar osteoblasts and THP-1 monocytes to study the osteogenic and inflammatory responses. In agreement with the proteomic results, Ca-enriched surfaces showed a significant initial inflammation that disappeared once the calcium was released. The distinct protein adsorption/desorption dynamics found in this work demonstrated to be useful to explain the differential biological responses between the titanium and Ca-ion modified implant surfaces.

Short Dental Implants (≤8.5 mm) versus Standard Dental Implants (≥10 mm): A One-Year Post-Loading Prospective Observational Study

Background: Recent data have shown that short dental implants can be the preferred treatment in most of cases of posterior atrophic alveolar ridges, offering higher survival and lower complication rates than long implants. The survival rates, stability, and marginal bone level changes were compared between short implants (7 and 8.5 mm) and standard-length implants (≥10 mm). Methods: Prospective observational study in which adult patients requiring ≥1 osseointegrated implants to replace missing teeth were recruited consecutively. A clinical examination was performed on the day the definitive prosthesis was placed and after 6 and 12 months. Implant stability quotient (ISQ), marginal bone level (MBL) changes, and the correlation between these parameters and the characteristics of the implants were evaluated. Results: A total of 99 implants were inserted (47 short, 52 standard) in 74 patients. The 12-month survival rate was 100%. ISQ values showed a similar pattern for both types of implants. No correlation was found between ISQ changes after one year and MBL values, nor between the latter and the characteristics of the implants. Conclusions: With clinical treatment criteria, shorter implants (7 and 8.5 mm in length) can be just as useful as standard-length implants in atrophic alveolar ridges, demonstrating similar rates of survival, stability, and crestal bone loss.