title: An analysis of the effect of tooth intrusion on the microvascular bed and fenestrae in the apical periodontal ligament of the rat molar.
abstract: An analysis of the rat apical periodontal ligament (PDL) microvascular bed and fenestrae was conducted to evaluate the effect of a continuous 1.0 N intrusive tooth load for 30 minutes. The microvascular bed consisted of postcapillary-sized venules, venous and arterial capillaries, and terminal arterioles. Intrusion produced significant increases (p less than 0.01) in vascular volume for postcapillary-sized venules and venous capillaries in three of the four animals. Arterial capillaries, overall, showed a statistically significant increase (p less than 0.01). The endothelial surface area (micron2 x 10(6)) per cubic millimeter of PDL responded variably in postcapillary-sized venules and venous capillaries but showed a strong trend to increase in arterial capillaries. After tooth intrusion a significant reduction (p less than 0.01) occurred in the number of fenestrae per square micrometer of endothelium in postcapillary-sized venules and venous capillaries. Fenestrae in the control PDL had a mean diameter of 51.5 nm +/- 0.6 (SE), whereas those on the intrusion side were smaller (p less than 0.05), measuring 49.9 nm +/- 0.4 (SE).
authors.affiliation: Department of Dentistry, University of Adelaide, Australia.
authors.forename: A B
authors.initials: AB
authors.lastname: Clark
authors.forename: M R
authors.initials: MR
authors.lastname: Sims
authors.forename: P I
authors.initials: PI
authors.lastname: Leppard
mesh_terms: D000818:Animals; D001160:Arterioles / Q000033:anatomy & histology / Q000502:physiology; D001810:Blood Volume; D002196:Capillaries / Q000033:anatomy & histology / Q000502:physiology / Q000648:ultrastructure; D002199:Capillary Permeability; D003799:Dental Stress Analysis; D004730:Endothelium, Vascular / Q000033:anatomy & histology*; D008297:Male; D008833:Microcirculation; D008963:Molar; D010513:Periodontal Ligament / Q000098:blood supply*; D051381:Rats; D014092:Tooth Root / Q000098:blood supply; D014651:Vasa Vasorum / Q000033:anatomy & histology; D014699:Venules / Q000033:anatomy & histology / Q000502:physiology