Occurrence of Progressive Bone Loss Around Anodized Surface Implants and Resorbable Blasting Media Implants: A Retrospective Cohort Study

The influence of two distinct surface modification techniques on the clinical efficacy of titanium implants: A systematic review and meta-analysis

PURPOSE

To compare the effectiveness of anodized and sandblasted large-grit acid-etched surface modification implants in clinical applications.

METHODS

This systematic review has been registered at PROSPERO (CRD42023423656). A systematic search was performed using seven databases. The meta-analysis was performed using the RevMan 5.4 program and Stata 17.0 software. An analysis of the risk of bias in the included studies was conducted using the Cochrane Handbook for Systematic Reviews of Interventions and the Newcastle-Ottawa scale.

RESULTS

A comprehensive analysis of 16 studies, which collectively encompassed a total of 2768 implants, was finished. Following a five years follow-up, the meta-analysis showed that the cumulative survival rate of implants was lower in the anodized group compared to the sandblasted large-grit acid-etched group (RR, 3.47; 95 % confidence interval [CI], 1.23 to 9.81; P = 0.02). Furthermore, the anodized group and the sandblasted large-grit acid-etched group had similar marginal bone loss over the one to three years follow-up period. However, it was observed that the marginal bone loss increased at the five years follow-up period in the anodized group in comparison to the sandblasted large-grit acid-etched group (SMD, 2.98; 95 % CI, 0.91 to 5.06; P = 0.005). In terms of biological complications, plaque index, bleeding on probing, and probing pocket depth, we found no statistically significant differences between the anodized and sandblasted large-grit acid-etched group.

CONCLUSIONS

The sandblasted large-grit acid-etched group exhibited higher implants cumulative survival rate and less marginal bone loss compared to the anodized group. Moreover, both groups demonstrated similar incidences of biological complications, plaque index, bleeding on probing, and probing pocket depth, suggesting overall equivalence in these aspects.

Microbial Adhesion and Biofilm Formation on Bioactive Surfaces of Ti-35Nb-7Zr-5Ta Alloy Created by Anodization

This study evaluated the microbial colonization (adhesion and biofilm) on modified surfaces of a titanium alloy, Ti-35Nb-7Zr-5Ta, anodized with Ca and P or F ions, with and without silver deposition. The chemical composition, surface topography, roughness (Ra), and surface free energy were evaluated before and after the surface modifications (anodizing). Adhesion and biofilm formation on saliva-coated discs by primary colonizing species (Streptococcus sanguinis, Streptococcus gordonii, Actinomyces naeslundii) and a periodontal pathogen (Porphyromonasgingivalis) were assessed. The surfaces of titanium alloys were modified after anodizing with volcano-shaped micropores with Ca and P or nanosized with F, both with further silver deposition. There was an increase in the Ra values after micropores formation; CaP surfaces became more hydrophilic than other surfaces, showing the highest polar component. For adhesion, no difference was detected for S. gordonii on all surfaces, and some differences were observed for the other three species. No differences were found for biofilm formation per species on all surfaces. However, S. gordonii biofilm counts on distinct surfaces were lower than S. sanguinis, A. naeslundii, and P. gingivalis on some surfaces. Therefore, anodized Ti-35Nb-7Zr-5Ta affected microbial adhesion and subsequent biofilm, but silver deposition did not hinder the colonization of these microorganisms.

Mechanical Properties and Microstructure of DMLS Ti6Al4V Alloy Dedicated to Biomedical Applications

The aim of this work was to investigate the microstructure and mechanical properties of samples produced by direct metal laser sintering (DMLS) with varied laser beam speed before and after heat treatment. Optical analysis of as-built samples revealed microstructure built of martensite needles and columnar grains, growing epitaxially towards the built direction. External and internal pores, un-melted or semi-melted powder particles and inclusions in the examined samples were also observed. The strength and Young's modulus of the DMLS samples before heat treatment was higher than for cast and forged samples; however, the elongation at break for vertical and horizontal orientation was lower than required for biomedical implants. After heat treatment, the hardness of the samples decreased, which is associated with the disappearance of boundary effect and martensite decomposition to lamellar mixture of α and β, and the anisotropic behaviour of the material also disappears. Ultimate tensile strength (UTS) and yield strength(YS) also decreased, while elongation increased. Tensile properties were sensitive to the build orientation, which indicates that DMLS generates anisotropy of material as a result of layered production and elongated β prior grains. It was noticed that inappropriate selection of parameters did not allow properties corresponding to the standards to be obtained due to the high porosity and defects of the microstructure caused by insufficient energy density.