Personal armor, including body armor, is protective clothing designed to either absorb or deflect attacks that would usually be fatal to an individual. These attacks include, but are not limited to, slashing, bludgeoning, stabbing and ballistic threats. In the UK, body armor is worn by police officers for their shift; however, military personnel (particularly when based overseas) may wear body armor continuously for much longer time periods. Thus, the effect of wear due to use on the performance of body armor is of interest. Testing of body armor after actual use is problematic for several reasons including, but not limited to, (i) access to such items and (ii) a lack of knowledge of exactly what the body armor has been exposed to. Thus the use of laboratory testing to understand degradation of body armor is of interest to many agencies. Additionally, laboratory testing allows for the effect of variables to be investigated independently of each other, as well as in combination. The effect of inter-layer wear between apparel items and/or among layers of fabric within apparel does not appear to be systematically explored in the literature. In this paper, the effect of wear on (i) the tensile strength and (ii) the fragment protective performance of fabrics packs containing a para-aramid woven fabric typical of those used to manufacture body armor was investigated.

Introduction: The role of bacteria in the etiology of peri‐implantitis has been reported in the literature. However, the influence of confounding factors on the disease remains unclear. The following case series discusses the presence of metal particles in diseased peri‐implant mucosa. Case Series: Four patients with peri‐implantitis underwent surgical peri‐implant therapy and diode laser surface decontamination procedures. Peri‐implant mucosa was excised under local anesthesia and samples were prepared for histology, scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) to evaluate peri‐implant tissues and identify deposits of foreign materials. Histologic examination demonstrated cellular fibrous connective tissue, with or without overlying stratified squamous epithelium. An inflammatory infiltrate consisting of a mixture of acute and chronic inflammatory cells was observed. Numerous deposits of granular foreign material were scattered within the connective tissue immediately below the epithelium. The presence of metal particles was evident in the SEM and confirmed by EDS. The size of titanium particles ranged from 2 to 15 μm. Additional particles, such as aluminum, phosphorous, and sulfur, were also found in some of the samples. Conclusions: All four cases yielded peri‐implant soft‐tissue specimens containing particulate black foreign material. SEM and EDS examination of histologic specimens confirmed the presence titanium particles and other elements in the peri‐implant tissues. Whether the presence of titanium particles in the surrounding tissue constitutes a biocompatibility issue is still a question that needs to be clearly evaluated.

In order to provide protection from fragmenting ballistic threats, combat body armour contains multiple layers of fabric. The garment covers the torso, but may provide (removable) protection to the upper arms, neck and groin. Such garments are thick, stiff, impede movement and increase the thermophysiological loading of the dismounted soldier. Examination of wound locations from recent conflicts has suggested it would be advantageous to provide protection to the extremities. Current modular systems can be expanded with strap-on coverings to the arms and legs, but this further exacerbates the mass, mobility and thermal problems already observed. Soldiers already wear coverings on their arms and legs in the form of a combat uniform, and the provision of a hierarchical protection system incorporated in the existing uniform has been discussed. Not all areas of the body would be protected to the same level. In the current work, the fragment protective capabilities of one or two layers of commercially available para-aramid woven fabric. Specifically, 1.1 g chisel-nosed fragment simulating projectile V50 data were obtained. The aim was to establish whether the incorporation of such one or two layers of para-aramid woven fabric into current combat clothing could provide a level of fragment protection with only a minimal associated increase in stiffness, mass and thermal resistance. Post-failure analysis was conducted to investigate inter-layer interaction and failure mechanisms. This work suggests that the use of one- and two-layer para-aramid woven fabric layers incorporated into clothing could offer some protection against wounding to the extremities from fragments.

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IntroductionPeri-implantitis is often regarded as a biological complication that may lead to late implant failure. However, the influence of confounding factors in this disease remains unclear. This case report highlights the interaction of other factors in the phenomena of crestal bone loss associated with implant placement and presents an interventional treatment strategy. Case presentationA 70-year-old female had been diagnosed with peri-implantitis associated with an implant that was placed to replace a mandibular molar tooth. There was progressive bone loss that continued despite the removal of the restoration. Peri-implant therapy included a surgical intervention with a modification of the restoration. Inflamed tissues were excised for histological evaluation. Metal-like particles were shown in cytological smears of peri-implant areas. Subsequent evaluation of the inflamed connective tissue using SEM, identified localized black-scattered material. EDS analysis confirmed the presence of not only titanium particles, but also gold, copper and silver particles with more particles at the junctional epithelium. ConclusionThis report highlights the interplay between different confounding factors in the development and progression of peri-implantitis and the importance of histological examination in the management of peri-implant diseases. Peri-implantitis is no longer a biological complication in which plaque is the sole factor. Functional wear, and implant surface deterioration may need to be taken into account in analysing the causes of crestal bone loss and implementing a multi-disciplinary treatment plan. Future intervention studies need to pay more attention to the increasingly crucial role played by the mechanical properties of the surrounding bone and dental implants.