Effect of Airborne-particle Abrasion on 3-dimensional Surface Roughness and Characteristic Failure Load of Fiber-reinforced Posts

Statement of problem Debonding is the most common complication of fiber-reinforced posts (FRPs). Airborne-particle abrasion (APA) has been suggested to increase resin cement adhesion to the surface of FRPs. However, which abrasion protocol is the most favorable is unclear. Purpose The purpose of this in vitro study was to compare the surface roughness and characteristic failure load of three FRP systems following different APA protocols. Material and methods A total of 150 posts from 3 manufacturers (glass FRP, quartz FRP, and zirconia-enriched glass FRP) were randomly assigned to different surface treatments (NT: no treatment—control; E0: cleaned with 96% ethanol solution; E2: APA for 2 seconds/mm2—ethanol cleaned, E5: APA for 5 seconds/mm2—ethanol cleaned; and E10: APA for 10 seconds/mm2—ethanol cleaned) forming 15 groups in total. APA was performed with 50-μm aluminum oxide. Each post was observed under a 3-dimensional (3D) laser microscope, and average 3D surface roughness (Sa) was measured. Failure was induced with a universal testing machine. Two specimens per group were evaluated under the same microscope to evaluate failure patterns. Surface roughness data were analyzed with the Welch ANOVA (α=.05), followed by the post hoc Games-Howell test. Failure load differences were determined by 2-parameter Weibull statistics and likelihood ratio contour plots (95% confidence bounds). Results Statistically significant differences were found in the mean surface roughness among the groups (Welch ANOVA, P Conclusions APA significantly increased surface roughness in all post systems. APA effects on characteristic failure load were dependent on the material used

Three-dimensional bio-printing and bone tissue engineering: technical innovations and potential applications in maxillofacial reconstructive surgery

Background Bone grafting has been considered the gold standard for hard tissue reconstructive surgery and is widely used for large mandibular defect reconstruction. However, the midface encompasses delicate structures that are surrounded by a complex bone architecture, which makes bone grafting using traditional methods very challenging. Three-dimensional (3D) bioprinting is a developing technology that is derived from the evolution of additive manufacturing. It enables precise development of a scaffold from different available biomaterials that mimic the shape, size, and dimension of a defect without relying only on the surgeon’s skills and capabilities, and subsequently, may enhance surgical outcomes and, in turn, patient satisfaction and quality of life. Review This review summarizes different biomaterial classes that can be used in 3D bioprinters as bioinks to fabricate bone scaffolds, including polymers, bioceramics, and composites. It also describes the advantages and limitations of the three currently used 3D bioprinting technologies: inkjet bioprinting, micro-extrusion, and laser-assisted bioprinting. Conclusions Although 3D bioprinting technology is still in its infancy and requires further development and optimization both in biomaterials and techniques, it offers great promise and potential for facial reconstruction with improved outcome

Applications of 3D printing on craniofacial bone repair: A systematic review

Objectives: Three-dimensional (3D) bioprinting, a method derived from additive manufacturing technology, is a recent and ongoing trend for the construction of 3D volumetric structures. The purpose of this systematic review is to summarize evidence from existing human and animal studies assessing the application of 3D printing on bone repair and regeneration in the craniofacial region. Data & sources: A rigorous search of all relevant clinical trials and case series was performed, based on specific inclusion and exclusion criteria. The search was conducted in all available electronic databases and sources, supplemented by a manual search, in December 2017. Study selection: 43 articles (6 human and 37 animal studies) fulfilled the criteria. The human studies included totally 81 patients with craniofacial bone defects. Titanium or hydroxylapatite scaffolds were most commonly implanted. The follow-up period ranged between 6 and 24 months. Bone repair was reported successful in nearly every case, with minimal complications. Also, animal intervention studies used biomaterials and cells in various combination, offering insights into the techniques, through histological, biochemical, histomorphometric and microcomputed tomographic findings. The results in both humans and animals, though promising, are yet to be verified for clinical impact. Conclusions: Future research should be focused on well-designed clinical trials to confirm the short- and long- term efficacy of 3D printing strategies for craniofacial bone repair. Clinical significance: Emerging 3D printing technology opens a new era for tissue engineering. Humans and animals on application of 3D printing for craniofacial bone repair showed promising results which will lead clinicians to investigate more thoroughly alternative therapeutic methods for craniofacial bone defects. © 2018 Elsevier Lt