Efficacy Of Chemo-Mechanical Removal Of Caries C. Haffner*, C. Benz, R. Hickel (Department Of Restorative Dentistry, Lmuniversity, Munich, Germany) Chemo-mechanical removal of caries is based on dissolving denatured collagen in the carious lesion and scraping out unsupported material with special curettes. The purpose of the present clinical study was to assess the in vitro efficacy of chemo-mechanical removal of caries with the Carisolv-method in comparison to conventional procedures.   40 freshly extracted human teeth with primary carious lesions were divided into four groups, one of them serving as a control sample and the other three each receiving a different treatment: In group A carious dentine was removed using a round No. 3 tungsten carbide bur (blend a med) in a slow-speed handpiece at approximately 700 rpm. In group B carious dentine was removed by means of an excavator (Aesculap). Teeth in group C were treated with an active gel containing 0.5% NaOCl, 0.1 M amino acids and a coloring substance (Carisolv). After 30 seconds the softened dentin was scraped out using the appropriately sized Carisolv-curette. Fresh gel was applied until no more debris could be removed. Ten untreated teeth in group 4 served as a control group. The complete removal of carious dentine was checked using a dental probe. Specimen were then sonicated and collected for scanning electron microscopy (SEM) analysis using a standardized caries scoring system.   According to the scoring system effective removal of caries could only be seen in groups A and C. The hand excavator was not able to sufficiently remove carious dentine, though it was used longer than seemed necessary to the operator. The SEM images showed an incomplete excavation with dentinal surfaces covered with denatured material. The surfaces of lesions treated with the conventional low speed bur were smooth and featureless and covered with a smear layer that almost obscured any dental anatomy. The chemo-mechanical caries removal displayed no smear layer and a multitude of open dentinal tubules.   The chemo-mechanical removal of caries offers an interesting alternative to the classical mechanical caries treatment.