MICROBIAL-CONTAMINATION IN 4 COMMERCIALLY AVAILABLE DENTURE ADHESIVES

Four brands of commercially available powder denture adhesives were te sted for microbial contamination. Sterile Petri plates that contained either brain-heart infusion (BHI) or Sabouraud's (SAB) agar were inocu lated with 0.5 gm samples of each adhesive. The BHI plates were incuba ted aerobically and anaerobically at 35 degrees C and the SAB plates a erobically at 30 degrees C for 2 weeks. The sterility of these procedu res was confirmed by incubating uninoculated control plates. All bottl es of powder denture adhesive tested contained microorganisms. Both ba cterial and fungal growth were noted. The containers of adhesive were then subjected to 10 minutes of microwave energy (650 W) to sterilize the adhesive material. After retesting, any bottles still contaminated were subjected to additional 10 minutes of microwave exposure and the n retested. Seven of 24 bottles still showed evidence of microbial con tamination after exposure to microwave energy. Of the seven bottles, f ive were of one brand. A Fisher's exact test showed significant differ ences in the percentage of contaminated samples between that and the o ther brands (p < 0.05). Microwave energy reduced microbial contaminati on in all samples but failed to completely sterilize seven of 24 sampl es.