The primary purpose of this study was to investigate the presence of blood or blood elements in aerosols generated during the debonding procedures. The presence of three hepatitis B carriers in the study group led us to investigate the possibility of hepatitis B virus (HBV) contamination through aerosols, which was the secondary purpose of the study. The study group consisted of 26 patients who had a mean age of 16 +/- 2 years. Collection of aerosol samples was done using a saliva ejector that fit on the handle of the high-speed dental instrument and was attached to a mobile evacuator. A second evacuator was used to remove and collect excess fluid accumulated in the patient's mouth. The guaiac method was used to investigate the presence of occult blood in aerosol and in excess fluid samples. Serum, excess fluid, and aerosol samples of three hepatitis B carriers were tested by enzyme-linked immunosorbent assay for detecting hepatitis B surface antigen (HBsAg) and by polymerase chain reaction for detecting HBV-deoxy-ribonucleic acid (DNA). Blood was found in all the aerosols and in excess fluid samples. HBsAg was detected in excess fluid samples of the two hepatitis B carriers, whereas HBV-DNA was detected in only one of the excess fluid samples. HBsAg and HBV-DNA were detected in aerosol sample of only one hepatitis B carrier. The results of this study showed that aerosols generated during the debonding procedure should always be considered as potential hazards to health.