Blood Reflux into Cartridge in Dental Anesthesia: Detection of total protein and human hemoglobin in residual anesthetic solution

The present study was designed to elucidate the blood reflux into cartridge under infiltration anesthesia. When imitation examination was carried out using pontamine blue dye solution in 7 kinds of syringes for the use of cartridge, dye reflux was observed in all of them. Compared 4 kinds of cartridges on the market, dye reflux was observed in all except one. The amounts of protein in residual anesthetic solution of cartridges after infiltration anesthesia were quantitatively measured by dye binding method. Human hemoglobin was also measured by enzyme immunoassay (EIA). The detection rates of protein and human hemoglobin were 26.2% (85/324) and 24.2% (24/99), respectively. From these facts that blood reflux cannot be avoided in the cartridge system, it is necessary to prohibit the reuse of residual anesthetic solution of cartridge as quickly as possible to avert the risk of cross infection of HB and AIDS virus.