RESUMEN
The dental unit waters are divided in two different groups, because of their chemical and microbial composition proprieties: in the first there is the "incoming dental unit water", drinking water that arrived directly in the dental chair unit through the municipal water system; in the second there is the "waste water", that represents the whole dental unit waste water. Regarding the lack of a complete systematic review on the quality of dental unit wastewater, the aim of the current research was to systematically study the incoming dental unit water and the waste one, focusing the attention on the problem of the wastewater contamination and its regulations. MATERIALS AND METHODS: A systematic literature review of the last 17 years was conducted on the topic of dental unit wastewater. Italian and English were the languages chosen for the papers research.Studies were searched in PubMed, Medline and Cochrane, with regard to inclusion criteria. RESULTS: The investigation and analysis of the two papers group revealed the presence of many information and scientific studies on the incoming dental unit water contamination, in contrast not much in literature about dental unit waste-water. CONCLUSIONS: The results revealed that dental unit wastewater is a problem underestimated by the scientific community, with the exception of dental amalgam wastes.In Italy there is a sentence of "Corte di Cassazione Penale, sez III, sentenza 17 gennaio 2013, n 2340" that regularized dental wastewaters as industrial ones, so they are inadequate to be disposed as domestic waters; but, at the same time, there isn't a specific law that regulates this king of waste.
