Fig. 3

Change in copy number of hepatitis B virus (HBV) DNA from fresh dentin to processed dentin. Copy numbers of 1.79 and 4.03 in two processed dentin samples (patients 3 and 14) corresponded with the fresh dentin samples containing the highest (a) and second highest (b) copy numbers (85.42 and 34.4, respectively) of HBV DNA were considered extensively degraded. Eight fresh dentin samples with HBV DNA copy numbers less than 31.9 were negative for HBV DNA in the processed dentin and considered to be completely degraded (inactivation or elimination of HBV). A copy number less than 10 is generally considered negative for virus, even though the cut off levels were not determined in the current experiment. With P < 0.05 being considered statistically significant, the correlation of copy number between fresh dentin and processed dentin was confirmed by multivariable logistic regression and determined to be statically significant (P = 0.0167)