Informed choices for challenging specimens when choosing methacrylate resin systems for histology

Abstract

Functional restoration for orthopedic, systemic, or dental purposes uses a diverse range of biomaterials. Monitoring for any subsequent failures associated with pathology is vital. To this end, an alternative methodology beyond that of cutting sections by conventional microtome knife-based histomethodologies was pioneered. The method was to saw a block of tissue followed by grinding the unsupported slice to the required thickness. The sawing and grinding of unsupported bones or teeth exposed not only the specimen fragility, but also the delicacy of the associated soft tissues. Although incomplete, the significance of the technique was recognized and improvements were incorporated which persist to the present day addressing the histopathology of challenging specimens. One major improvement for preserving cellular structure as well as reducing fracture incidence was achieved by impregnating tissue samples with cross-linked resins prior to the cutting and grinding processes. Methyl and glycol methacrylate resins superseded all other choices because of the advantages of photo-initiated curing. Further pioneering work led to the formulation of increasingly appropriate resin systems and the subsequent processing protocols evolved, as clinical needs for histology-specific techniques became apparent. Over the decades, several key pioneers entered this scientific arena to develop the now established resin formulation, processing protocols, and allied applications. This has led to the commercialization of the various resin systems. The aim here is to discuss the commercially available glycol and methyl methacrylate resin systems and their practical application to a variety of important techniques used in the histological assessment of complex pathology specimens.

Comparison of three different techniques for histological tooth preparation

“…Especially, investigation of calcification areas in pulp or diagnosis of metabolic bone diseases where normal calcification process is impaired may be often necessary. Since the use of GMA-and MMA-based resin embedding systems is often required in the assessment of implanttissue integration, further methodological studies to improve quality of hard tissues visualisation at the microscopic level have to be continued [25]. The results of our study suggest that for routine histochemical assessment and H&E staining of such sections, the MMA-based embedding material may be preferred instead of GMA-based resins.…”

Evaluation of laser ablation microtomy for correlative microscopy of hard tissues

“…Methods for embedding mixed hard and soft tissues in resins to permit thin sectioning with saws followed by serial grinding to produce thin sections are well known in the literature (Gross & Strunz, 1977;Donath & Breuner, 1982;Plenk, 1986;Wolf et al, 1992;Erben, 1997;Singhrao et al, 2012). They all aim to make it possible to have thin slices where all the parts are intact and properly connected.…”

“…(1) To saw off the block face with a water-cooled diamond saw blade or band saw as in the Exakt system (Donath & Breuner, 1982) after sticking it to a slide: then grinding and polishing a section (Gross & Strunz, 1977;Plenk, 1986;Wolf et al, 1992;Erben, 1997;Singhrao et al, 2012). The disadvantage is the huge loss of tissuetypically 500 µm -per slicing event, which is impractical for most samples and impossible for small samples such as mouse bones or small surgical biopsy samples or rare tissue samples, and serial sectioning is impossible.…”

Decision tree analysis as a supplementary tool to enhance histomorphological differentiation when distinguishing human from non-human cranial bone in both burnt and unburnt states: A feasibility study

“…However, in order to reduce micro fractures, and the trapping fine dust during the grinding and polishing steps, the methodology of Cattaneo et al 2,3 may eventually be superseded by acrylic resin-based methodologies that involve infiltration of the resin into the tissue specimen prior to polymerization and/or direct mounting onto the glass slide. 13 Thus, better histological preparation of the already compromised tissue specimens for clarity of the final histological presentation is also important for an accurate interpretation of bony structures from difficult forensic specimens. Given that the trends toward the Regulatory Governance of expert witnesses as well as new rules of evidence admissibility (e.g.…”

“…formalin), dehydrated or infiltrated with resin for bone histology techniques. 12,13 Instead, all cranial bone samples were prepared following the currently established methods described by Cattaneo et al 2,3 for forensic bone histomorphological investigations. Samples from each specimen (both human and nonhuman) were paired, with one set burnt while and the other was left unburnt.…”