Page 24 - Craventreatiseonpyorrh00crav

14 PYORRHCEA ALVEOLAEI8. — tracted a congestion of tracts involved in the pus cavities is rarely observed. The progress of the disease is indicated by a deepening of the " pockets," to which the further encroachment or even the continued presence of calculus of any character is not essen- tial. On the other hand, incrustations may serve to perpetu- ate the chronic character of the disease without inducing acute manifestations or apparent progress. INVISIBLE CALCULUS. At a remote, or at best an obscure point upon the affected side of a root, in a deep " pocket," the observant operator dis- covers an incrustation that is essentially different from that which has been called visible or plain salivary calculus. The hidden calculus usually is discoverable to the sense of touch through a delicate instrument. Efforts to remove the crust prove it to be more adherent than ordinary visible tartar ; that the mass is smaller, or often is spread thinly out over the surface of the root ; that it is found separate from the visible variety, from which it differs materially in appearance. Probably there is no point in connection with a considera- tion of the entire subject of pyorrhoea alveolaris, upon which there exists a greater diversity of opinions than as to the char- acter and origin of the calculus found so tenaciously adhering to roots in the pus " pockets." This particular deposit has been variously ascribed as salivary, sanguinary and serumal the latter two terms being employed synonymously by many. The terms ss.ngu;ina;ry ar^d serumal are applied to the calcu- 1 lus in those case's 'wTrefe there appears to be no opening for in-