Pyrozone has the same formula as peroxide of hydrogen, and is presented in the form of solution only. Various percentages have been produced which are devoid of poisonous properties and other objectionable features. It is presented in the following percentages: An aqueous medicinal solution of pyrozone, 3 per cent.; an ethereal solution which is antiseptic, 8 per cent., and a caustic ethereal solution of 25 per cent., - all of the same formula H202.

Medical Properties And Action

The medicinal 3 per cent, aqueous solution acts with great rapidity, causing instant effervescence, and is a harmless antiseptic externally or internally. It is nearly neutral, and its cleansing effects in removing mucus are very effective. The ethereal 5 per cent. solution is powerfully antiseptic, and acts on pus with remarkable energy.

The caustic 25 per cent. solution, also ethereal, is the most powerful, and both it and the 5 per cent. solution, when applied to the skin, cause a tingling sensation and a marble whiteness, similar in appearance to that caused by carbolic acid; the discoloration of the pyrozone, however, disappears after some hours without leaving any marks or other bad effects.

The 25 per cent. solution is not only a powerful caustic, but is also considered to be a very safe one, as the rapid evaporation of its solvent - ether- leaves the concentrated H202 behind. When not in use these solutions should be kept from contact with organic matters, on account of their rapid action. All of the pyrozone solutions are prompt hemostatics; but the 3 per cent. solution is the best for such a purpose, for the reason that its caustic action is less than that of the 5 per cent. or 25 per cent. solutions.

All of the pyrozone solutions are bleachers, but the 5 per cent. and 25 per cent. solutions act more promptly for such a purpose, on account of the action of the hydrogen on organic coloring matter, and not by reaction due to acid. The painful sensation produced by the stronger solutions coming in contact with a healthy surface may be quickly relieved by rubbing freely with tannin and glycerine; and if gloves are worn on the hands placed in pockets, any stains on the fingers will disappear within one hour, and no sloughing or soreness result. Care should be exercised as to the quantity of the pyrozone solution employed; hence cotton, or silk ropes, or tampons should not be so saturated as to permit an excess to be forced out and come in contact with healthy tissues or surfaces when the pyrozone is employed in a pocket or fistula. The 3 per cent medicinal solution is put up in 4 ounce glass-stoppered bottles, and the 5 per cent and 25 per cent solutions in sealed glass tubes, the contents of which can be transferred to clean glass bottles with ground stoppers, not filled too full, and kept in an upright position.

Therapeutic Uses

The 3 per cent solution of pyrozone, being free from odor and toxic properties, may be used with advantage when carbolic acid or other disinfectant is indicated. In certain forms of indigestion or dyspepsia, ulcers of the stomach, and gastritis, the 3 per cent solution may be given internally in doses of Therapeutic Uses 1367 three times a day before meals. In long-standing epilepsy, Dr. B. W. Richardson has administered it in doses twice daily. Externally, the 5 per cent and 25 per cent solutions have been employed in rhinitis, ulcerations, diphtheria, syphilitic ulcerations, old sinuses, fistulous tracts from bone disease, lupus erythematous, alopecia areata, ringworm, nasal diseases, etc., etc.

Dental Uses

The 3 per cent aqueous solution may be used freely as a mouth wash, also as a gargle, but considerable irritation follows its contact with the throat. Used as a mouth wash it will remove the oily deposit and absorbent coating on the teeth of smokers; also as an irrigating and detergent wash in abscesses, sinuses and ulcerations. The 3 per cent aqueous solution is also recommended by Dr. C. B. Atkinson as a valuable adjunct in caring for a frequent condition of children's mouths, where, from malnutrition during gestation and the sundry eczemas of childhood, the teeth become pitted or wasted of the enamel, by which cavities are exposed to the destructive influence of caries, as the 3 per cent solution both bleaches teeth in this condition and retards the progress of destruction.

The 3 per cent solution is also effective as a wash or injection into large abscess pockets as an excellent cleanser and means of cure. As a bleaching agent the 3 per cent. solution, however, is less penetrating in its effects than either the 5 per cent. or 25 per cent. solutions; and used as a spray it will by its oxydizing effect bring to the surface from between the teeth any pus present. It will also act upon any incrustations about the teeth, softening them and rendering their removal easy.

The 5 per cent. ethereal solution is employed in abscess pockets, fistula or sinuses, fistulous roots, alveolar pyorrhoea, small quantities only being used at a time. The solution may be dropped from an ordinary glass stopper, a drop at a time until the desired effect is produced ; or it may be applied on a tapered piece of orange wood, or an attenuated glass rod, or as an injection with a syringe, or by a special pyrozone atomizer in the form of spray. In treating fistulae of alveolar abscesses, the solution may be introduced on cotton or other tents, so that it may be carried well within the tract.

The 5 per cent. solution is also an efficient bleacher of discolored teeth, and causes no injurious action on the tooth structure, or on myxomatous tissues; and its application to ulcerating surfaces brings about a rapid reduction of the suppuration without a resulting coagulum.

The 5 per cent ethereal solution of pyrozone appears to be more generally serviceable, but if the ether is permitted to evaporate it may become caustic, as concentration follows evaporation. For bleaching discolored teeth, a pledget of cotton saturated with the solution may be placed in the cavity, and the surface of the crown of the tooth be wiped over with the same 5 per cent. solution; it is also useful in removing the green stain common on the necks of children's teeth, but care must be taken that the solution does not touch the gums. Great care must also be taken not to allow the stronger pyrozone solutions to come in contact with an exposed pulp, as it expands such a tissue very greatly, and as a consequence causes excruciating pain.

The 25 per cent. solution of pyrozone is caustic in its action, and its use in preference to the 5 per cent. solution will depend upon the depth or rapidity of action required, as the 5 per cent.

solution causes less pain, and may answer better when the mucous membrane is very irritable. To bleach a discolored tooth, or to rapidly cleanse a surface, or where the disease is difficult to reach on account of its depth, the 25 per cent. solution answers better than the 5 per cent. solution, on account of its prompt action. The antiseptic and caustic solutions of pyrozone attack the hydrogen in the color compound in the tubuli, and when this is given off only water remains. For bleaching teeth the rubber dam is first adjusted, and the apical foramen of the root sealed ; then by means of a glass atomizer, the pyrozone is sprayed into the pulp-chamber and canal, and also into the crown cavity. The effect is prompt and satisfactory. The solution may also be applied on cotton or bibulous paper, but no metallic instruments should be used in connection with the agent ; and to renew the application it is better to drop the pyrozone on the cotton or paper, and not dip again into the bottle.

Pyrozone atomizers are constructed with three tubes, one each for the upper and lower teeth, and one straight tube for spraying other parts. For treating putrescent pulps and alveolar abscesses, the dam is adjusted, and the solution of pyrozone carried into the root and apical space in the form of spray, or on cotton at the end of a wooden probe; the pyrozone being applied until the pus ceases to flow, when the root canal is filled with cotton, which is allowed to remain until the following day, when the filling may be inserted, or, if necessary, a second application of pyrozone made, which, however, is seldom, if ever, required. The contact of the antiseptic, and especially of the caustic solution of pyrozone, with the gum or skin, causes a severe burning or pricking sensation, causing a white stain, more of the nature of a bleached spot than a true eschar, which may be prevented by previously painting the exposed parts with glycerin. The pain may be relieved by the application of glycerin, or glycerite of tannin, or a solution of bicarbonate of soda Dental Uses 1369 to

For the deep pockets of alveolar pyorrhoea, a small tent of cotton may be saturated with the 25 per cent solution, and its application will in most cases terminate the suppuration. (See Suppurative Gingivitis.)

In opening glass tubes containing pyrozone by filing a notch and then breaking off" the point, care must be taken that particles of the glass do not enter the eye, by sudden explosion, and destroy the sight.