Fibril Diameters in the Extracellular Matrix of the Periodontal Connective Tissues of the Rat

Abstract

The diameters of collagen fibrils were measured in three varieties of periodontal connective tissue in the rat mandible (incisor periodontal ligament, incisor enamel-related connective tissue and molar periodontal ligament). Despite structural and functional differences between the tissues, a similar range of collagen fibril diameters was seen in each (average 45 nm). Variation between animals and between adjacent fiber bundles in any given tissue was observed. Even within any single fiber bundle, the fibrils had a variety of diameters. Although it has been claimed that collagen fibrils have diameters which are multiples of 8 nm, such a relationship could not be discerned for periodontal collagen fibrils. It was estimated that about 65 per cent of a periodontal collagen fiber bundle or sheet is composed of ground substance. Despite reports of abundant oxytalan fibers in periodontal tissues at the light microscope level, only one fiber having characteristics of oxytalan was observed in this electron microscopic study. Some aspects of the functional significance of the findings are discussed.

Distinct post‐translational features of type I collagen are conserved in mouse and human periodontal ligament

“…Collagen fibril diameter varies between species, tissues, tissue sites and age . Previous studies have shown that the PDL fibril diameters in both rodent and human teeth are relatively small, ranging from ~45 to 55 nm . Our TEM data support that collagen fibrils have comparable diameters in mouse and human PDL (~57 nm).…”

“…35 Previous studies have shown that the PDL fibril diameters in both rodent and human teeth are relatively small, ranging from ~45 to 55 nm. 36,37 Our TEM data support that collagen fibrils have comparable diameters in mouse and human PDL (~57 nm). Tissues that are under high tension or compressive stress, such as PDL, typically have smaller diameter collagen fibrils with more interfibrillar cross-links, which facilitate the return to the tissue's original form.…”

An immunohistochemical study examining the role of collagen type VI in the rodent periodontal ligament

“…The apparent absence of stain for collagen type VI in the mid-zone cannot be explained by a simple lack of collagenous matrix in the region, as transmission electron microscope studies (Berkovitz et al, 1981;Berkovitz & Moxham, 1989) have demonstrated a homogeneous distribution of banded collagen fbrils across the ligament. The staining pattern may, however, be related to the architecture of the banded fibrils.…”

Do collagen fibrils of the periodontal ligament shrink with age?

“…This being accepted, the present data can be seen in context with analogous data derived from other tissues and species. It is well known that, in general, the collagen fibril diameter varies considerably between about 15 and 300 nm (13)(14)(15). Depending on the type of tissue, age and species, the collagen fibril diameter may also be related to the type and amount of glycosaminoglycans in the surrounding matrix as well as to the functional status of the tissue involved (15).…”

“…Respective data for collagen fibrils of the periodontal ligament are still scarce. Around continuously growing incisors and the molars of immature rats, the average collagen fibril diameter ranges between 43 and 48 nm, although 85% of the fibrils vary widely from 30 to 55 nm (14,18). Apart from the unsupported data of Gathercole & Keller (1), suggesting that collagen fibrils of the human periodontal ligament fall from about 70 nm in young to about 30 nm in old subjects, the present study provides the first comprehensive set of data on the human periodontal ligament.…”