User:Oiguodala/sandbox

"Direct neural theory dentin contains nerve endings that respond when stimulated. the pulp is well innervated, especially below the odontoblasts (plexus of rackshow) and some nerves penetrate a short distance in some tubules. whether these intratubular nerves are incolved in dentin sensitivity is not known" no evidence found for nerves in outer dentine which is most sensitive

odontoblast receptpr theory this mechanism explains dentine sensitiviy considers the odontoblasts to be recepor cells. this attractive conxps has been cconsidered abandoned and reconsiderred for many reasosns

it was once argued that becuase odontoblast is of neural crest origin it retaint an ability to traansduce and propagate an inpulse; whta is missing wass demonstration of synaptic relation between odontoblasts and pulpal nerves

transducer theory dentinal sensation takes into consideration the synapticlike relationship betwwen the terminal senory nerve endings and odontoblastic processes, if ture neural transmitters e.g. ACh could be expected but no evidence of its presence

when dentin is first exposed, small blebs of fludi can be seen on the cavity floor, when the cavity is driedwith air or cotton wool a greater loss of fluid is induced leading to more movement and further painful experience

this increased sensitivity at the dentino-enamel junction is explained by the profice branching od tubules in this region

interestingly stimuli like cold ehich cause flow away from pulp produce more rapud and greater pullp nerve response than those like heat which cause inwaord flow

evidece from scanning electron microscopic invesingation of extractd teeth suggests thte there are differences between hypersensitive and non-sensitive dentine in that there are more and wider open dentinal tubules in sensitive dentine

additionaly another SEM study based on replica models of hypersensitivity showed tht in hypersensitive dentine the smear layers was thinner and different in structire thin in the non sensitive dentin

Pages to finish/ add to:
 * Ferrule effect (dental)
 * Perikyma