The ART technique consists of hand excavating carious tissue and placing a highly viscous glass ionomer cement as a restoration material and as a sealant. Although the results of several studies are promising, the retention rates of these restorations for primary teeth are not impressive. Materials and methods that yield greater success rates are needed to improve long-term caries management outcomes. In principle, ART should yield outcomes similar to those associated with preservative dentistry, including the potential for minimal surgical intervention, conservation of sound tooth structure, avoidance of pain and need for local anesthetic injections, reduced risk for subsequent endodontics and tooth extraction, and increased survival time of the affected teeth. The ideal direct-filling ART material would be biocompatible and tooth colored; "forgiving" in its handling properties; insensitive to moisture or desiccation; hardenable without special equipment; able to form stable bonds to enamel and dentin; able to seal marginal gaps against bacteria; capable of releasing fluoride or remineralization and antibacterial agents when demineralization is most likely; and resistant to chemical attack. The highly viscous glass ionomer materials currently used for ART meet several of this criteria, though they may be deficient in their ability to seal marginal gaps against bacteria and in their sensitivity to desiccation. Furthermore, although they release fluoride over the lifetime of the restoration, this fluoride release alone may not prevent caries progression in all cases. It is necessary for cases of high caries risk to use chlorhexidine in conjunction with fluoride to achieve caries arrest and remineralization of adjacent areas of the affected teeth. Thus, while the ART technique offers some benefits in restoring function and reducing the rate of caries progression, it is unlikely that current materials will be able to arrest caries progression completely in high-risk persons.