Richard C Petersen's research while affiliated with University of Alabama at Birmingham and other places

Publications (17)

Article
Soaring gold prices have created an almost impossible void in the Dental Materials supply reserves for affordable patient posterior crowns. Fortunately, aerotech fiber-reinforced composite (FRC) materials in use for many diverse structural applications can be developed for dentistry to replace gold with computer-assisted design/computer-assisted ma...
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Newer dental fiber-reinforced composites can provide service with less wear than enamel. Further, fibers in bulk molding form pack oriented parallel to the occlusal-dentinal floor planes that wear by uniform thinning into micrometer-sized fiber remnants and subsequent flat plate-like particulate bond by compression back into the polymer matrix. The...
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A breakthrough has been discovered in pathology chemistry related to increasing molecular structure that can interfere with oxygen diffusion through cell membranes. Free radicals can crosslink unsaturated low-viscosity fatty acid oils by chain-growth polymerization into more viscous liquids and even solids. Free radicals are released by mitochondri...
Article
Clinicians have been aware that posterior dental particulate-filled composites (PFCs) have many placement disadvantages and indeed fail clinically at an average rate faster than amalgam alloys. Secondary caries is most commonly identified as the chief failure mechanism for both dental PFCs and amalgam. In terms of a solution, fiber-reinforced compo...
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Three-dimensional (3D)-woven noncrimp fiber-reinforced composite (FRC) was tested for mechanical properties in the two principal directions of the main XY plane and compared to different Computer-Aided-Design/Computer-Aided-Machining (CAD/CAM) Dental Materials. The Dental Materials included ceramic with Vitablock Mark II®, ProCAD®, InCeram® Spinel,...
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Triclosan antimicrobial molecular fluctuating energies of nonbonding electron pairs for the oxygen atom by ether bond rotations are reviewed with conformational computational chemistry analyses. Subsequent understanding of triclosan alternating ether bond rotations is able to help explain several material properties in Polymer Science. Unique bond...
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Carbon fibers have multiple potential advantages in developing high-strength biomaterials with a density close to bone for better stress transfer and electrical properties that enhance tissue formation. As a breakthrough example in biomaterials, a 1.5 mm diameter bisphenol-epoxy/carbon-fiber-reinforced composite rod was compared for two weeks in a...
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Photocure fiber-reinforced composites (FRCs) with varying chopped quartz-fiber lengths were incorporated into a dental photocure zirconia-silicate particulate-filled composite (PFC) for mechanical test comparisons with a popular commercial spherical-particle amalgam. FRC lengths included 0.5-mm, 1.0 mm, 2.0 mm, and 3.0 mm all at a constant 28.2 vol...
Article
Triclosan is a diphenyl ether antimicrobial that has been analyzed by computational conformational chemistry for an understanding of Mechanomolecular Theory. Subsequent energy profile analysis combined with easily seen three-dimensional chemistry structure models for the nonpolar molecule Triclosan show how single bond rotations can alternate rapid...
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The aim of the article is to present recent developments in material research with bisphenyl-polymer/carbon-fiber-reinforced composite that have produced highly influential results toward improving upon current titanium bone implant clinical osseointegration success. Titanium is now the standard intra-oral tooth root/bone implant material with bioc...
Article
Single-bond rotations or pyramidal inversions tend to either hide or expose relative energies that exist for atoms with nonbonding lone-pair electrons. Availability of lone-pair electrons depends on overall molecular electron distributions and differences in the immediate polarity of the surrounding pico/nanoenvironment. Stereochemistry three-dimen...
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Polymer free-radical lipid alkene chain-growth biological models particularly for hypoxic cellular mitochondrial metabolic waste can be used to better understand abnormal cancer cell morphology and invasive metastasis. Without oxygen as the final electron acceptor for mitochondrial energy synthesis, protons cannot combine to form water and instead...
Article
Critical stress intensity factor (KIc) has been an approximation for fracture toughness using only load-cell measurements. However, artificial man-made cracks several orders of magnitude longer and wider than natural flaws have required a correction factor term (Y) that can be up to about 3 times the recorded experimental value [1-3]. In fact, over...
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Aims: To provide common Organic Chemistry/Polymer Science thermoset free-radical crosslinking Sciences for Medical understanding and also present research findings for several common vitamins/antioxidants with a new class of drugs known as free-radical inhibitors. Study design: Peroxide/Fenton transition-metal redox couples that generate free ra...
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Aerospace/aeronautical thermoset bisphenyl-polymer/carbon-fiber-reinforced composites are considered as new advanced materials to replace metal bone implants. In addition to well-recognized nonpolar chemistry with related bisphenol-polymer estrogenic factors, carbon-fiber-reinforced composites can offer densities and electrical conductivity/resisti...

Citations

... Thus, compliance with this range has to be achieved clinically. This is known to directly impact periodontal health outcomes and can lead to localized inflammation and gingival recession [5,6]. Increased plaque accumulation aggravates periodontal tissue inflammation and reduces clinical longevity [7,8]. ...
... This increases the viscosity of the mixture and makes the uniform dispersion of fibers in resin monomers difficult or creates air-void spaces [34,49]. This is especially true for nanofibers, whose high active surface area, even at small concentrations, may also increase the viscosity of the resin and thereby hinder its clinical use [50]. ...
... FRC adhesive bonding then also offers the convenience for fabricating a crown with an occlusal escape vent to relieve hydraulic cement pressures that prevent complete seating onto the tooth margin [38][39][40]. Subsequent filling of the vent hole can then be easily facilitated with high success using an advanced FRC molding compound [41][42][43][44][45][46]. ...
... An important focus for research is the accumulation of mineral pigments (on the type of exogenous pigments deposition) which can be caused by the disadvantage of dental materials using (due to imbibition of dentinal tubules and intermaxillary prisms with silver compounds) and tobacco etc. Also, it is important to note that different inflammatory processes which are accompanied by dystrophic and degenerative processes in the oral cavity can have an effect on tooth "pigment dystrophy" [8,15,16,21]. ...
... Perhaps at higher concentrations of RONS, free radicals can change the membrane uidity and increase its sti ness, which may be due to the interaction of free radicals with PUFAs. 19,20 According to the present study, it can be concluded that due to the amount of RONS produced in the cell culture medium, there was no signi cant change in cell sti ness and viscosity of the environment, and as a result, the fractal factor remained almost unchanged, which is a good sign, and shows the success of cold plasma-based treatments. However, this may not happen at higher powers. ...
... Compared with traditional laminates and 2D woven composites, 3D woven composites have weft and warp yarns woven multilayers, resulting in improved delamination resistance, higher damage tolerance, reduced notch sensitivity and improved fracture toughness [4][5][6]. Threedimensional woven composites are good candidates for structural applications with outof-plane and impact loading conditions and have been widely used in the aerospace, automotive, construction, biomedicine and safety industries [7][8][9][10][11]. ...
... TCS has been widely used as an antimicrobial additive in food storage containers and kitchen utensils, commonly marketed under the trademark Microban ® [55,56]. In those household articles, TCS is generally incorporated directly into the polymer matrix before curing in concentrations up to 1% (w/w) [57,58]. TCS is also marketed under the trade name Microban ® when it is used in plastics and clothing, and Biofresh ® when it is used in acrylic fibers [59]. ...
... FRC adhesive bonding then also offers the convenience for fabricating a crown with an occlusal escape vent to relieve hydraulic cement pressures that prevent complete seating onto the tooth margin [38][39][40]. Subsequent filling of the vent hole can then be easily facilitated with high success using an advanced FRC molding compound [41][42][43][44][45][46]. ...
... Their tensile strengths range from 5.65 GPa to 1.5 GPa, and their specific modulus ranges from 106 GPa to 407 GPa [255], exceeding the strength and modulus of steel-2.39 GPa and 26.6 GPa, respectively [256]. CNFs are broadly utilized as reinforced and conductive elements in polymers and composites in general [257]. ...
... FRC polymer matrices provide design options with specialty additives or resins to develop hydrophobic materials and the opportunity to incorporate the efficacious and hydrophobic Triclosan antimicrobial [47][48][49]. ...