J. Yousefian et al., A NEW EXPERIMENTAL-MODEL FOR STUDYING THE RESPONSE OF PERIODONTAL-LIGAMENT CELLS TO HYDROSTATIC-PRESSURE, American journal of orthodontics and dentofacial orthopedics, 108(4), 1995, pp. 402-409
An apparatus was developed to apply positive or negative hydrostatic p
ressure dynamically to periodontal ligament (PDL) cells in vitro, The
objective of this investigation was to construct this apparatus and to
determine its effects on PDL cells. Human PDL cells were collected fr
om freshly extracted premolars. At the sixth passage, the cells were m
echanically stimulated by this apparatus at different magnitudes of co
ntinuous positive or negative hydrostatic pressures (PHP or NHP, respe
ctively). The application of PHP between 0.3 and 30 gm/cm(2) significa
ntly enhanced prostaglandin E (PGE) production and intracellular cycli
c AMP (cAMP) of the cells. In contrast, perturbation by NHP significan
tly decreased PGE production and intracellular level of cAMP. Prolifer
ation rate increased significantly at 24 and 48 hours due to stimulati
on of these cells with -30 gm/cm(2) of NHP. Challenging these cells wi
th +30 gm/cm(2) of PHP significantly decreased the proliferation rate
of these cells at 24 and 48 hours. Stimulation by PHP between +30 to 600 gm/cm(2) increased cell length and width and appeared to increase
surface area attachment to the bottom of the culture dishes. in contra
st, NHP (between -30 and -600 gm/cm(2)) decreased these dimensions and
appeared to reduce the surface area of attachment. These results indi
cate that this type of mechanical perturbation of PDL cells produces p
hysiologic responses and is not detrimental to their vitality.