Removal of Enamel Caries with a Novel Air-abrasion Powder

Objectives: To compare the efficiency of enamel caries removal using air-abrasion with an experimental selective enamel powder (SEP) to alumina powder and a negative and positive control group. Methods: Ninety-three extracted permanent human molars with non-cavitated incipient enamel carious lesions were selected. After root embedding, every lesion was sectioned through its center perpendicularly to the surface, photographed and classified microscopically as having dentin involvement or not. An equal number of enamel caries lesions with or without dentin involvement were distributed into four groups with different treatment modalities. Group 1: SEP-abrasion (Air-Flow with DCP, EMS, Nyon, Switzerland); 2: alumina-abrasion (Air-Flow Prep K1 Max, EMS); 3 (negative control): sodium bicarbonate-abrasion (Air-Flow Classic Lemon, EMS); 4 (positive control): diamond bur preparation. Surfaces were re-photographed after treatment. The Kruskal-Wallis test was performed to compare groups 1-4 (α=0.05). The Wilcoxon Mann-Whitney test was applied to each group to test for an influence of dentin involvement (α =0.05) and to test for pairwise comparisons (α =0.01). Results: Superimposition of the photographs of all groups resulted in areas of “correct-excavation”, “under-excavation” and “over-excavation”. For groups 2-4 there were no statistical differences between lesions with or without dentin involvement. However, in the SEP group (1) all measured areas were significantly influenced by dentin involvement (p=0.01) with 20% of correct excavation when only enamel was involved and 70% correct-excavation when dentin was involved. No significant differences were found between the alumina (2) and bur (4) groups. SEP, however, performed significantly poorer for enamel caries without dentin involvement compared to alumina (p<0.01) but performed equally to alumina and bur in lesions with dentin involvement. Conclusion: SEP ablative properties varied dependently on dentin involvement. SEP did not abrade tooth structure when caries was present only in enamel. In terms of dental treatment SEP seems to have diagnostic properties.