Assessment of the Potential Role of Preoperative Dental Clearance in Total Joint Arthroplasty Optimization: A Pilot Study.

Aims And Objectives: Periprosthetic joint infection (PJI) is a serious complication after total joint arthroplasty (TJA) and is associated with significant morbidity, mortality, and cost. This pilot study primarily aimed to investigate if preoperative dental screenings would impact the rate of PJI following TJA when compared to historical controls. Secondarily, this study aimed to evaluate the prevalence of dental pathology in patients undergoing TJA.

Quantifying Nanoparticle Ordering Induced by Polymer Crystallization.

It has recently been established that polymer crystallization can preferentially place nanoparticles (NPs) into the amorphous domains of a lamellar semicrystalline morphology. The phenomenology of this process is clear: when the time for NP diffusion is shorter than the crystal growth time, then the NPs are rejected by the growing crystals and placed in the amorphous domains. However, since there is no quantitative characterization of this ordered NP state, we develop a correlation function analysis for small-angle X-ray scattering data, inspired by classical methods used for enunciating the local morphology of lamellar semicrystalline polymers.

Mechanisms of Directional Polymer Crystallization.

Zone annealing, a directional crystallization technique originally used for the purification of semiconductors, is applied here to crystalline polymers. Tight control over the final lamellar orientation and thickness of semicrystalline polymers can be obtained by directionally solidifying the material under optimal conditions. It has previously been postulated by Lovinger and Gryte that, at steady state, the crystal growth rate of a polymer undergoing zone annealing is equal to the velocity at which the sample is drawn through the temperature gradient.

Effects of Hairy Nanoparticles on Polymer Crystallization Kinetics.

We previously showed that nanoparticles (NPs) could be ordered into structures by using the growth rate of polymer crystals as the control variable. In particular, for slow enough spherulitic growth fronts, the NPs grafted with amorphous polymer chains are selectively moved into the interlamellar, interfibrillar, and interspherulitic zones of a lamellar morphology, specifically going from interlamellar to interspherulitic with progressively decreasing crystal growth rates. Here, we examine the effect of NP polymer grafting density on crystallization kinetics.

Nanoparticle Organization by Growing Polyethylene Crystal Fronts.

We investigate the crystallization-induced ordering of C grafted 14 nm diameter spherical silica nanoparticles (NPs) in a short chain ( = 4 kDa, ≈ 2.3) polyethylene and a commercial high-density polyethylene ( = 152 kDa, ≈ 3.2) matrix.

Exchange Lifetimes of the Bound Polymer Layer on Silica Nanoparticles.

Understanding the structure and dynamics of the bound polymer layer (BL) that forms on favorably interacting nanoparticles (NPs) is critical to revealing the mechanisms responsible for material property enhancements in polymer nanocomposites (PNCs). Here we use small angle neutron scattering to probe the temporal persistence of this BL in the canonical case of poly(2-vinylpyridine) (P2VP) mixed with silica NPs at two representative temperatures. We have observed almost no long-term reorganization at 150 °C (∼ + 50 °C), but a notable reduction in the BL thickness at 175 °C.

Tunable Multiscale Nanoparticle Ordering by Polymer Crystallization.

While ∼75% of commercially utilized polymers are semicrystalline, the generally low mechanical modulus of these materials, especially for those possessing a glass transition temperature below room temperature, restricts their use for structural applications. Our focus in this paper is to address this deficiency through the controlled, multiscale assembly of nanoparticles (NPs), in particular by leveraging the kinetics of polymer crystallization. This process yields a multiscale NP structure that is templated by the lamellar semicrystalline polymer morphology and spans NPs engulfed by the growing crystals, NPs ordered into layers in the interlamellar zone [spacing of [Formula: see text] (10-100 nm)], and NPs assembled into fractal objects at the interfibrillar scale, [Formula: see text] (1-10 μm).