Mechanical Testing and Evaluation of Eight Synthetic Casting Materials

Abstract

Eight synthetic casting materials were evaluated with respect to tensile and fatigue strengths, exothermicity (evolution of heat during polymerization), permeability (porosity), radiolucency, and cost. Strength determination for a five‐layer sample included measurement of the ultimate load at which a material failed, the ability to absorb energy, and the stiffness a material possessed after application of a cyclic stress. Results indicated that Vet Cast was superior with respect to tensile and fatigue strengths. The exothermic reaction associated with the “curing” or polymerization process was evaluated and not considered excessive although Ultra Cast attained a temperature of 48.0°C and was uncomfortable to handle during application. Permeability was determined. Delta Lite and Hexcelite NS were the most permeable materials and dried more rapidly and thoroughly after immersion than the other casting materials. Hexcelite NS was considered the least radiolucent material and was the most expensive material studied. Each of the synthetic casting materials demonstrated superiority in one or more of the categories tested. No one product demonstrated consistent superiority in criteria appropriate for clinical application.

Evaluation of the effects of initial water temperature and curing time on fiberglass cast strength

“…The cast construction model was designed to minimize variation between constructs and to mimic the clinical situation. Uneven distribution of resin within the cast tape during long storage times has been reported and correlated with poor lamination after application . All casting material used was from the same manufacturer's lot, the storage time between first and last construct was minimized, and water was changed for every cast to avoid resin contamination.…”

“…Uneven distribution of resin within the cast tape during long storage times has been reported and correlated with poor lamination after application. 15,16 All casting material used was from the same manufacturer's lot, the storage time between first and last construct was minimized, and water was changed for every cast to avoid resin contamination. Although lamination could be affected by the tension applied in the cast tape and in clinical situations some tension is applied, the tension used in this model was minimal and was selected to ensure consistency in each construct by spinning the mandrel instead of tensing the tape.…”

Racecourse fracture management. Part 2: Techniques for temporary immobilisation and transport

“…Fibreglass tape impregnated with water‐activated polyurethane resin is universally recommended and adopted as the material of choice for all equine casting techniques (Bartels et al . ; Houlton and Brearley ; Murray and De Bowes ; Gomez and Stashak ). The resin is activated by dipping in water and is temperature dependent.…”

“…If appropriate limb/joint positions can be obtained, casts offer the best immobilisation/stabilisation and counter pressure of all temporary immobilisation techniques (Fig 7). Fibreglass tape impregnated with water-activated polyurethane resin is universally recommended and adopted as the material of choice for all equine casting techniques (Bartels et al 1985;Houlton and Brearley 1985;Murray and De Bowes 1996;Gomez and Stashak 2008). The resin is activated by dipping in water and is temperature dependent.…”

Mechanical Evaluation of Soft Cast (Scotchcast, 3M) and Conventional Rigid and Semi-rigid Coaptation Methods

“…Rigid coaptation methods include full cylinder casts made of plaster of Paris or synthetic cast materials that rigidly immobilize at least two joints. Synthetic fibreglass or polyester tapes impregnated with water activated polyurethane resin replaced the traditional plaster of Paris and provide substantial advantages by means of breaking strength, strength-to-weight ratio, drying time, radiolucency and resistance to water damage (2,4,8,(13)(14)(15)(16).…”