[Inhibiting effect of a pyrophosphate-dentifrice on calculus formation].
Anticalculus dentifrices containing pyrophosphate salts have been shown to reduce calculus formation. The purpose of this double-blind, cross-over study was to compare the effects of a pyrophosphate dentifrice with a placebo on supragingival calculus formation in highly calculus-prone subjects. 60 volunteers completed a compliance period during which meticulous full-mouth scaling was performed. Subjects were randomly assigned either to placebo (F-Antibelag Gel) or to the test group (F-Antibelag Gel + K4P2O7/Na4P2O7). Participants were told to brush twice daily with their assigned dentifrice, use only the brushes provided and to abstain from any other oral hygiene procedures. After a three month period a second full-mouth scaling was performed, and according to the cross-over design of this study the participants used the alternative placebo or, respectively, dentifrice for another three months. Baseline scores and control scores after 1, 2 and 3 months were obtained using the Volpe-Manhold-Index and the Marginal-Line-Calculus-Index. A micromorphological SEM Calculus Index was introduced using replicas from interdental areas of mandibular incisors (score 0-3). Both test groups showed significantly less accumulation of supragingival calculus of 25.5% (VMI) and 19.5% (MLCI) and significantly less SEM detectable calculus (24%) with the pyrophosphate dentifrice than with the placebo. It is concluded that the test dentifrice inhibits the formation of calculus.