[Acid application on dental tartar as preliminary treatment before mechanical scaling]

The action of the preparation studied, containing 20% hydrochloric acid in an alcohol-chloroform medium: 1) affected both white tartar as well as the submucosal tartar, progressively replacing the phosphorus radicles of tricalcium phosphate by CL ions, transforming the insoluble tricalcium phosphate into soluble calcium chloride; 2) was practically complete in 2 minutes; 3) was more rapid on tartar than on enamel or even cement; 4) did not appear to alter the superficial structure of the tooth in 4 minutes whilst, for the same period of time, the superficial structure of the cement was deeply attacked with 50% preparations of citric acid or phosphoric acid; 5) in our trials, carried out after 4 minutes treatment, caused the tartar to undergo a relatively superficial but adequate chemical action to facilitate its removel, whilst leaving the underlying hard tissue, enamel or cement, unharmed. It would thus appear that such a substance may be used for the preparation and speeding of mechanical descaling.