Most of the restorative dentists still practice complete carious tissue removal to hard dentin, relying on hardness as the most important criterion for excavation. Only a few dentists chose partial caries removal and a high percentage of them think that cariogenic microorganisms must be removed or caries would progress. It can be concluded that the new knowledge and concepts about caries lesions and the more conservative approach to deep carious lesions have not yet been incorporated by most of the restorative dentists into their usual clinical practice. Although dental professionals have plenty access to scientific knowledge, this knowledge is not being translated into daily clinical practice.Partial caries excavation has a high success rate to treat deep carious lesions in permanent teeth which indicates that the retention of carious dentin does not interfere with pulp vitality.It is impossible to achieve sterile cavities but clinical observations have proven that enclosing bacteria underneath a restoration should not give clinical complications. However, more research is necessary to evaluate the effect of microorganisms and their toxins on the pulp.