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The adaptive nature of the bone-periodontal ligament-cementum complex in a ligature-induced periodontitis rat model.

Lee JH, Lin JD, Fong JI, Ryder MI, Ho SP - Biomed Res Int (2013)

Bottom Line: TRAP(+) cells on both sides of the complex significantly increased at 8 days.A gradual change in fibronectin expression from the distal PDL-secondary cementum interfaces through precementum layers was observed when compared to increased and abrupt changes at the mesial PDL-cementum and PDL-bone interfaces in ligated and control groups.Based on our results, we hypothesize that compromised strain fields can be created in a diseased periodontium, which in response to prolonged function can significantly alter the original bone and apical cementum formations.

View Article: PubMed Central - PubMed

Affiliation: Division of Biomaterials and Bioengineering, Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, CA 94143, USA.

ABSTRACT
The novel aspect of this study involves illustrating significant adaptation of a functionally loaded bone-PDL-cementum complex in a ligature-induced periodontitis rat model. Following 4, 8, and 15 days of ligation, proinflammatory cytokines (TNF- α and RANKL), a mineral resorption indicator (TRAP), and a cell migration and adhesion molecule for tissue regeneration (fibronectin) within the complex were localized and correlated with changes in PDL-space (functional space). At 4 days of ligation, the functional space of the distal complex was widened compared to controls and was positively correlated with an increased expression of TNF- α. At 8 and 15 days, the number of RANKL(+) cells decreased near the mesial alveolar bone crest (ABC) but increased at the distal ABC. TRAP(+) cells on both sides of the complex significantly increased at 8 days. A gradual change in fibronectin expression from the distal PDL-secondary cementum interfaces through precementum layers was observed when compared to increased and abrupt changes at the mesial PDL-cementum and PDL-bone interfaces in ligated and control groups. Based on our results, we hypothesize that compromised strain fields can be created in a diseased periodontium, which in response to prolonged function can significantly alter the original bone and apical cementum formations.

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Related in: MedlinePlus

Line profiles and micrographs of immunolabeled fibronectin (FN). Representative micrographs illustrate FN immunofluorescence in apical regions of control and ligated complexes at 4, 8, and 15 days. The intensity of FN expression was measured along the anatomical locations indicated by the 300 μm long bar. For the mesial complex, the x-axis of the 300 μm long profile corresponds to alveolar bone (AB), periodontal ligament (PDL), secondary cementum (SC), and dentin (D). Note that the direction for the distal complex is reversed. (a1) 4-day control mesial complex, (a2) 4-day control distal complex, (a3) 4-day ligated mesial complex, (a4) 4-day ligated distal complex, (b1) 8-day control mesial complex, (b2) 8-day control distal complex, (b3) 8-day ligated mesial complex, (b4) 8-day ligated distal complex, (c1) 15-day control mesial complex, (c2) 15-day control distal complex, (c3) 15-day ligated mesial complex, and (c4) 15-day ligated distal complex. Dentin (D), secondary cementum (SC), periodontal ligament (PDL), alveolar bone (AB), new bone (NB).
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fig6: Line profiles and micrographs of immunolabeled fibronectin (FN). Representative micrographs illustrate FN immunofluorescence in apical regions of control and ligated complexes at 4, 8, and 15 days. The intensity of FN expression was measured along the anatomical locations indicated by the 300 μm long bar. For the mesial complex, the x-axis of the 300 μm long profile corresponds to alveolar bone (AB), periodontal ligament (PDL), secondary cementum (SC), and dentin (D). Note that the direction for the distal complex is reversed. (a1) 4-day control mesial complex, (a2) 4-day control distal complex, (a3) 4-day ligated mesial complex, (a4) 4-day ligated distal complex, (b1) 8-day control mesial complex, (b2) 8-day control distal complex, (b3) 8-day ligated mesial complex, (b4) 8-day ligated distal complex, (c1) 15-day control mesial complex, (c2) 15-day control distal complex, (c3) 15-day ligated mesial complex, and (c4) 15-day ligated distal complex. Dentin (D), secondary cementum (SC), periodontal ligament (PDL), alveolar bone (AB), new bone (NB).

Mentions: On the mesial side, FN expressions were illustrated as sharp peaks at both PDL-bone and PDL-cementum interfaces, regardless of the experimental condition and time point. However, the width of high FN intensity was wider in the ligated group compared to controls (Figures 6(a1), 6(a3), 6(b1), 6(b3), 6(c1), and 6(c3)). On the distal side, the display of FN over a larger width of cementum from the PDL-cementum attachment site was observed. On the other hand, only a sudden drop of intensity with no peak at the PDL-bone attachment site was shown (Figures 6(a2), 6(a4), 6(b2), 6(b4), 6(c2), 6(c4), and Figure S2).


The adaptive nature of the bone-periodontal ligament-cementum complex in a ligature-induced periodontitis rat model.

Lee JH, Lin JD, Fong JI, Ryder MI, Ho SP - Biomed Res Int (2013)

Line profiles and micrographs of immunolabeled fibronectin (FN). Representative micrographs illustrate FN immunofluorescence in apical regions of control and ligated complexes at 4, 8, and 15 days. The intensity of FN expression was measured along the anatomical locations indicated by the 300 μm long bar. For the mesial complex, the x-axis of the 300 μm long profile corresponds to alveolar bone (AB), periodontal ligament (PDL), secondary cementum (SC), and dentin (D). Note that the direction for the distal complex is reversed. (a1) 4-day control mesial complex, (a2) 4-day control distal complex, (a3) 4-day ligated mesial complex, (a4) 4-day ligated distal complex, (b1) 8-day control mesial complex, (b2) 8-day control distal complex, (b3) 8-day ligated mesial complex, (b4) 8-day ligated distal complex, (c1) 15-day control mesial complex, (c2) 15-day control distal complex, (c3) 15-day ligated mesial complex, and (c4) 15-day ligated distal complex. Dentin (D), secondary cementum (SC), periodontal ligament (PDL), alveolar bone (AB), new bone (NB).
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3713652&req=5

fig6: Line profiles and micrographs of immunolabeled fibronectin (FN). Representative micrographs illustrate FN immunofluorescence in apical regions of control and ligated complexes at 4, 8, and 15 days. The intensity of FN expression was measured along the anatomical locations indicated by the 300 μm long bar. For the mesial complex, the x-axis of the 300 μm long profile corresponds to alveolar bone (AB), periodontal ligament (PDL), secondary cementum (SC), and dentin (D). Note that the direction for the distal complex is reversed. (a1) 4-day control mesial complex, (a2) 4-day control distal complex, (a3) 4-day ligated mesial complex, (a4) 4-day ligated distal complex, (b1) 8-day control mesial complex, (b2) 8-day control distal complex, (b3) 8-day ligated mesial complex, (b4) 8-day ligated distal complex, (c1) 15-day control mesial complex, (c2) 15-day control distal complex, (c3) 15-day ligated mesial complex, and (c4) 15-day ligated distal complex. Dentin (D), secondary cementum (SC), periodontal ligament (PDL), alveolar bone (AB), new bone (NB).
Mentions: On the mesial side, FN expressions were illustrated as sharp peaks at both PDL-bone and PDL-cementum interfaces, regardless of the experimental condition and time point. However, the width of high FN intensity was wider in the ligated group compared to controls (Figures 6(a1), 6(a3), 6(b1), 6(b3), 6(c1), and 6(c3)). On the distal side, the display of FN over a larger width of cementum from the PDL-cementum attachment site was observed. On the other hand, only a sudden drop of intensity with no peak at the PDL-bone attachment site was shown (Figures 6(a2), 6(a4), 6(b2), 6(b4), 6(c2), 6(c4), and Figure S2).

Bottom Line: TRAP(+) cells on both sides of the complex significantly increased at 8 days.A gradual change in fibronectin expression from the distal PDL-secondary cementum interfaces through precementum layers was observed when compared to increased and abrupt changes at the mesial PDL-cementum and PDL-bone interfaces in ligated and control groups.Based on our results, we hypothesize that compromised strain fields can be created in a diseased periodontium, which in response to prolonged function can significantly alter the original bone and apical cementum formations.

View Article: PubMed Central - PubMed

Affiliation: Division of Biomaterials and Bioengineering, Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, CA 94143, USA.

ABSTRACT
The novel aspect of this study involves illustrating significant adaptation of a functionally loaded bone-PDL-cementum complex in a ligature-induced periodontitis rat model. Following 4, 8, and 15 days of ligation, proinflammatory cytokines (TNF- α and RANKL), a mineral resorption indicator (TRAP), and a cell migration and adhesion molecule for tissue regeneration (fibronectin) within the complex were localized and correlated with changes in PDL-space (functional space). At 4 days of ligation, the functional space of the distal complex was widened compared to controls and was positively correlated with an increased expression of TNF- α. At 8 and 15 days, the number of RANKL(+) cells decreased near the mesial alveolar bone crest (ABC) but increased at the distal ABC. TRAP(+) cells on both sides of the complex significantly increased at 8 days. A gradual change in fibronectin expression from the distal PDL-secondary cementum interfaces through precementum layers was observed when compared to increased and abrupt changes at the mesial PDL-cementum and PDL-bone interfaces in ligated and control groups. Based on our results, we hypothesize that compromised strain fields can be created in a diseased periodontium, which in response to prolonged function can significantly alter the original bone and apical cementum formations.

Show MeSH
Related in: MedlinePlus