640 THE TEETH. 



THE PULP OF THE TOOTH. BY C. F. W. BOEDECKER, D. D. S., M. D. S.* 



(1) Methods. The best method for the examination of pulp-tissue is to 

 place the tooth, immediately after its removal from the mouth, in an aqueous 

 solution of chromic acid, of one-half to one per cent, in strength, to which 

 from time to time a few drops of dilute hydrochloric acid may be added. 

 After a few weeks the peripheral portion of the dentine has become suffi- 

 ciently soft to be cut by a razor. When, in cutting, the hard portions of the 

 dentine are reached, the extraction of the lime-salts must be continued in the 

 above described manner until the razor meets with the central cavity and its 

 tenant, the pulp. 



Another method is to split the tooth, as soon as possible after its extrac- 

 tion, with a strong pair of excising forceps. The teeth best adapted for this 

 method are the incisors, canines, and bicuspids. Immediately moisten the 

 exposed pulp with a solution of chloride of sodium, of the strength of about 

 one-half per cent., and then remove the pulp. If the pulp is to be stained 

 with carmine, hsematoxylon, fuchsine, osmic acid, picro-indigo, or chloride of 

 gold, etc., after its removal from the hard parts of the tooth, place it in the 

 staining fluid. Among the re-agents mentioned, I have found but one of con- 

 siderable value viz.: the one-half per cent, solution of chloride of gold. 

 This re-agent can be applied to fresh pulps as well as to very thin sections 

 obtained after hardening in chromic acid. It may be allowed to remain in 

 contact with the specimen for from twenty to thirty minutes. In a few days 

 fresh specimens will assume a bright violet color, while sections which have 

 previously been in a chromic acid solution become brownish-violet. Osmic 

 acid, in a solution of one per cent., renders the contours of the constituent 

 tissues, and especially those of the medullated nerve-fibers, more distinct. 

 Both fresh and chromic acid specimens may be treated with it. Thin sections 

 do not require more than one hour's exposure to this re-agent, while whole 

 fresh pulps may be left in it for two or three hours. Except the ammoniacal 

 solution of carmine, which is known to be suitable for staining certain parts of 

 the tissue, I would not lay stress upon applying any of the other re-agents 

 mentioned. 



If a fresh pulp is thin enough it may, immediately after its removal from 

 the split tooth, be transferred to the slide with the addition of an indifferent 

 fluid, such as the solution of chloride of sodium. Fresh pulps of lower incisors, 

 being the thinnest, are best adapted for examining the system of blood-vessels ; 

 shortly afterward, however, Ihe vessels fade away. Isolated pulps may be 

 placed between two plates of fine cork, and thus cut into thin sections with 

 the razor. 



(2) The minute structure of normal pulp-tissue. If we examine a thin longitu- 

 dinal or transverse section of the pulp with low powers of the microscope, we 

 recognize a large number of blood-vessels and bundles of medullated nerve- 

 fibers. The majority of these blood-vessels are capillaries ; the veins are less 

 numerous and the arteries scarce. In many pulps we find no arteries at all, 

 in others a limited number, particularly in the root portion of the pulp, and 

 also in the middle of the medullated nerve-bundles. The latter mostly run in 

 a longitudinal direction, but not infrequently we observe smaller bundles, or 



* Abstract of the author's paper, " The Minute Anatomy of the Dental Pulp in its Physio- 

 logical and Pathological Conditions." The Dental Cosmos, Philadelphia, 1882. 



