Taking all this into consideration, it seems prudent to divide the prevalence of this condition into three categories: DH prevalence using surveys (around 50 %); DH prevalence diagnosed using combined surveys and clinical exams (15–20 %); and DH in patients who have periodontal disease or have been receiving periodontal treatment (60–90 %). Referring back to the definition of DH previously mentioned, the latest category might reflect a different etiology and should not be considered when reporting prevalence of the condition. Bacteria were reported to penetrate dentin to a considerable distance in periodontally diseased teeth (Adriaens et al. 1988). Such sensitivity of dentin therefore is a separate clinical entity possibly requiring different preventive and management strategies (Dababneh et al. 1999).