In vitro measurement of regional differences in the mechanical properties of the periodontal ligament in the rat mandibular incisor

Chiba, M.; Yamane, Akira; Ohshima, S.; Komatsu, Koichiro

doi:10.1016/0003-9969(90)90177-c

Cited by 45 publications

(26 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The degree of mineralization of Sharpey fibers, and thus their form of either projections or depressions in relation to the bone surface, has been related to their mechanical effectiveness (Currey, 1984;Short and Johnson, 1990). The results herein described are in line with the observations by Chiba et al (1990) and Komatsu et al (1998), that the mechanical properties of the periodontal ligament of continuously erupting incisors increase in incisal direction. It was also shown in rat incisors that the molecular organization of periodontal ligament collagen fibers increases from basal to incisal (Komatsu et al, 2002).…”

Section: Discussionsupporting

confidence: 92%

Alveolar bone Sharpey fibers of the rat incisor in normal and altered functional conditions examined by scanning electron microscopy

Silva

Merzel

2004

Anat. Rec.

View full text Add to dashboard Cite

The morphology and the area density of Sharpey fibers in the socket of the rat incisor under normo-, hyper-, and hypofunctional conditions were evaluated using scanning electron microscopy. Sharpey fibers appeared either as dome-shaped projections, when highly mineralized, or as depressions when less mineralized. Near the alveolar crest, most of the fibers were fully mineralized and arranged in compact longitudinal rows. Toward the basal end of the socket, the rows became interrupted, forming islets of gradually smaller size and number. The density of the Sharpey fibers was higher (P Ͻ 0.01) in the mesial and distal faces than in the lingual face in most of the socket length. In normofunctional conditions, in all faces the density decreased 70 to 90 times from the crestal toward the basal region of the socket (P Ͻ 0.01). The degree of mineralization of the Sharpey fibers also decreased steadily in the same direction, indicating that, for support, the periodontal ligament matures from basal to incisal and is fully developed only in the crestal region. In hyper-and hypofunctional conditions, the same distribution was observed. The area density of the Sharpey fibers in the hyperfunctional condition showed a slight increase at the basal levels of the socket mesial and distal faces (P Ͻ 0.01 or P Ͻ 0.05). In hypofunctional incisors, the density decreased significantly (P Ͻ 0.01) at the mesial and distal faces in all regions of the socket, and at the lingual face, the decrease (P Ͻ 0.05) was restricted to the incisal regions. This may be one of the factors for the weakening of the periodontal ligament in hypofunctional incisors.

show abstract

Section: Discussionsupporting

confidence: 92%

Alveolar bone Sharpey fibers of the rat incisor in normal and altered functional conditions examined by scanning electron microscopy

Silva

Merzel

2004

Anat. Rec.

View full text Add to dashboard Cite

show abstract

“…5) suggest that the degree of molecular alignment and packing conditions, as well as the content of the collagen fibrils, increases in the incisal direction. This notion is supported by the finding that the mechanical strength of the rat incisor periodontal ligament increases from the basal toward the incisal regions along the tooth (Chiba et al, 1990;Komatsu et al, 1998). By contrast, the lower retardation values for the intermediate area of the ligament along the incisor (Fig.…”

Section: Discussionmentioning

confidence: 65%

Polarized light microscopic analyses of collagen fibers in the rat incisor periodontal ligament in relation to areas, regions, and ages

Komatsu¹,

Mosekilde²,

Viidik³

et al. 2002

Anat. Rec.

View full text Add to dashboard Cite

We prepared decalcified sagittal sections (20 m thick) from the incisal, middle, and basal regions of the mandibular incisor of male Wistar rats aged 2, 6, 12, and 24 months, and examined the sections using polarized light microscopy. Most of the birefringent fibers appeared to run obliquely across the periodontal ligament. Birefringent fibers running parallel to the long axis of the incisor were also found in the intermediate area of the ligament. Similar fiber architecture was observed in all four age groups. Quantitative analysis showed that the retardation values of collagen were higher in the bone-and tooth-related areas and lower in the intermediate area of the ligament. The values for the bone-and tooth-related areas increased from the basal toward the incisal regions in all four age groups. Age-related changes in the retardation values were found only in the incisal region of the incisor. In the incisal region, the values for the bone-and tooth-related areas increased markedly from 2-24 months of age, whereas those for the intermediate area increased slightly but significantly with age. Our findings indicate that the degrees of molecular organization and alignment of collagen fibers in the bone-and tooth-related areas of the ligament are higher than those in the intermediate area and increase near the incisal region and with age. It is also suggested that the collagen fibers in the intermediate area remain immature along the long axis of the incisor throughout the life span of the animal. Anat Rec 268: 381-387, 2002.

show abstract

“…The radiographic images were processed in an image analyzer (Luzex 3U, Nikon, Tokyo, Japan). The circumferences of the tooth and socket wall, the perimeters of the lingual cementum and socket wall between the enamel/cementum junctions on both sides of the tooth, and the sectional area of the lingual periodontal ligament were then measured (Komatsu, 1988;Chiba et al, 1990). The area of the periodontal ligament facing the cementum (AP in mm 2 ) was calculated as, AP ϭ thickness of section ϫ perimeter of cementum; and the average width of the periodontal ligament (WP in mm) was also calculated as, WP ϭ sectional area of the periodontal ligament / (perimeter of cementum ϩ perimeter of socket wall) / 2.…”

Section: Radiographic Analysismentioning

confidence: 99%

“…Then, by dividing the load values by the surface area of the periodontal ligament and deformations by the width of the ligament, the load-deformation curve is standardized into a shear stress-strain curve (Ralph, 1982;Mandel et al, 1986;Komatsu, 1988;Chiba et al,1990). Such stress-strain relations allow for comparisons of the biomechanical prop-erties between different species and between different sizes or locations of specimens (Viidik, 1980a).…”

mentioning

confidence: 99%

Comparison of biomechanical properties of the incisor periodontal ligament among different species

et al. 1998

Self Cite

View full text Add to dashboard Cite

These results suggest that the regional differences in the biomechanical properties of the periodontal ligament depend upon the developmental stages of the periodontal collagen fibers that may be related to the general arrangement, diameters, and densities of the collagen fiber bundles and the fiber insertions into the alveolar bone and cementum. The species differences in the biomechanical properties may be due to differences in the width of the periodontal ligament and the waviness as well as the strength and stiffness of the periodontal collagen fibers.

show abstract

In vitro measurement of regional differences in the mechanical properties of the periodontal ligament in the rat mandibular incisor

Cited by 45 publications

References 31 publications

Alveolar bone Sharpey fibers of the rat incisor in normal and altered functional conditions examined by scanning electron microscopy

Alveolar bone Sharpey fibers of the rat incisor in normal and altered functional conditions examined by scanning electron microscopy

Polarized light microscopic analyses of collagen fibers in the rat incisor periodontal ligament in relation to areas, regions, and ages

Comparison of biomechanical properties of the incisor periodontal ligament among different species

Contact Info

Product

Resources

About