A Quanticalc clinical comparison of professional efficiency in manual supragingival calculus debridement.

The Quanticalc (QC) dental scaler permits the assessment of work effort expended by professionals in removing supragingival calculus from the teeth. The purpose of this study was to compare the efficiency of two professionals in scaling calculus under controlled clinical conditions in like populations. One-hundred and thirty-one subjects were randomly assigned to two professionals, A and B, for QC scaling of their six Volpe-Manhold Index (VMI) teeth. VMI assessments were carried out by a separate examiner prior to QC cleaning. The QC was used to record total developed force, total strokes and force/stroke used in calculus debridement. Results demonstrated significant differences in scaling efficiency between the two professionals. These results further demonstrate the potential utility of the QC and like devices in assisting in the instruction of professionals toward the development of more efficient manual scaling procedures.

Kinetic factors influencing the dissolution behavior of calcium oxalate renal stones: a constant composition study.

A constant composition method has been used to examine the dissolution kinetics of calcium oxalate renal stones over a wide range of undersaturation in vitro. Demineralization experiments have been carried out with the concentrations of calcium and oxalate ions and ionic strength (hence the solution undersaturation) held constant by the potentiometrically controlled addition of medium electrolyte solution as diluent, triggered by a calcium ion electrode. Kinetic data for renal stones have been compared with results obtained for synthetic calcium oxalate. In addition, constant composition results have been directly compared with results obtained using conventional dissolution methods for both calculi and synthetic calcium oxalate. Overall, calcium oxalate renal stones exhibited markedly different kinetic dissolution behavior as compared with synthetic controls. The renal stone samples dissolved more slowly at all undersaturations, exhibited increased kinetic orders of reaction, and showed reduced sensitivity to solution hydrodynamics. Stones composed of mixed hydrates of calcium oxalate (mono- and di-) came to dihydrate equilibrium in conventional experiments and underwent net dissolution in solutions supersaturated to monohydrate under constant composition conditions. No conversion of di- to monohydrate was observed under these experimental conditions. These results indicate that stone dissolution is strongly influenced by adsorbed inhibitors, presumably including matrix components, which may complicate efforts to develop systemic and/or irrigation measures effective for in situ solubilization.