Publications

This review evaluates the effect of magnesium (Mg)-doped coatings on the osseointegration of titanium (Ti)-based implants. The recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and the PRISMA 2020 Statement were followed, with registration in PROSPERO (CRD42024572571). The PICOS strategy was based on population: dental implants; intervention: Mg coatings; control: surfaces without Mg; outcomes: bone-implant contact (BIC), bone area (BA), implant stability coefficient (ISQ), and removal torque (RTQ); and study Design: in vivo studies. The SYRCLE tool was used to assess the risk of bias of animal studies. Meta-analyses were performed, using a random-effect model and 95% confidence interval. Twenty-three records were included, and 21 were enrolled in the meta-analyses. The most commonly used Mg doping method was microarc oxidation. The Mg-doped coatings, significantly favored pooled BIC values in animals [-6.09 (-8.35, -3.82), I-2: 50%, p < 0.00001], especially up to 3, 4, 6, and 8 weeks compared to surfaces without Mg. Interestingly, Mg-doped coatings favored BA up to 6 weeks [-8.20 (-14.31, -2.09), I-2: 0%, p = 0.008], and RTQ up to 3 [-8.44 (-12.33, -4.56), I-2: 63%, p < 0.0001]. Conversely, it did not influence ISQ [-0.24 (-2.05, 1.58), I-2: 88%, p = 0.80]. Mg-doped coatings significantly enhanced osseointegration in dental implants by improving BIC, BA, and RTQ, while showing no impact on ISQ. Supported by studies across various animal species, these results confirm that such coatings represent an effective and safe approach for promoting bone integration.

JTD Keywords: Alloys, Bone, Bone-implant interface, Dental implant, Dental implants, Expression, Incorporated oxidized implants, Ion-implantation, Magnesium, Mg, Osseointegration, Resonance frequency measurements, Strength, Surface-chemistry

The efficiency of synthetic bone grafts can be evaluated either in osseous sites, to analyze osteoconduction or ectopically, in intramuscular or subcutaneous sites, to assess osteoinduction. Bone regeneration is usually evaluated in terms of the presence and quantity of newly formed bone, but little information is normally provided on the quality of this bone. Here, we propose a novel approach to evaluate bone quality by the combined use of spectroscopy techniques and nanoindentation. Calcium phosphate scaffolds with different architectures, either foamed or 3D-printed, that were implanted in osseous or intramuscular defects in Beagle dogs for 6 or 12 weeks were analyzed. ATR-FTIR and Raman spectroscopy were performed, and mineral-to-matrix ratio, crystallinity, and mineral and collagen maturity were calculated and mapped for the newly regenerated bone and the mature cortical bone from the same specimen. For all the parameters studied, the newly-formed bone showed lower values than the mature host bone. Hardness and elastic modulus were determined by nanoindentation and, in line with what was observed by spectroscopy, lower values were observed in the regenerated bone than in the cortical bone. While, as expected, all techniques pointed to an increase in the maturity of the newly-formed bone between 6 and 12 weeks, the bone found in the intramuscular samples after 12 weeks presented lower mineralization than the intraosseous counterparts. Moreover, scaffold architecture also played a role in bone maturity, with the foamed scaffolds showing higher mineralization and crystallinity than the 3D-printed scaffolds after 12 weeks.

JTD Keywords: Atr-ftir, Bone regeneration, Calcium-phosphate, Ectopic implantation, Implant interface, In-vivo, Indentation, Mechanical-properties, Micromechanical properties, Nanoindentation, Orthotropic implantation, Raman spectroscop, Raman-spectroscopy, Strengt, Substitutes