Use of Clinical UV Chamber to Disinfect Dental Impressions: A Comparative Study

Abstract

Introduction: Dental impressions are potential source of infection in a prosthodontic practice. Risk of transmission of infection through saliva, blood etc is considered as hazard for both dentist as well as dental auxiliary staff. A number of methods are currently employed for disinfecting the impressions which are technique sensitive and time consuming. This study focuses on disinfecting impression using dental UV chamber which is commonly employed for storing sterilized instruments.

Aim: The aim of this invitro study was to evaluate the use of clinical UV chamber to disinfect various impression materials at different time intervals and its comparison with 2% glutaraldehyde using standard immersion technique.

Materials and methods: Total sample size of 180 specimens was taken from three different impression materials. The impressions were made from 30 dentulous subjects. A total of ten impressions were made for each impression material i.e. alginate, addition silicone and polyether impression material. Six punch samples were taken from each impression. Out of 6 punch sample, one was kept as control, second was disinfected by immersing in freshly prepared 2% glutaraldehyde solution for 10 minutes and remaining four were exposed to UV rays for 3 minutes, 6 minutes, 10 minutes and 15 minutes using dental UV chamber. Amount of disinfection achieved was evaluated by counting the colonies over the culture plates with the help of digital colony.

Results: The results showed that the mean CFUs for alginate were found to be i.e. 11797.40 ± 5989.73 (mean ± SD). The mean CFUs for addition silicone impression material was found 7095.40 with a standard deviation of 4268.83 and the mean CFUs for polyether impression material was found to be 2168.92 ± 1676 (mean ± SD).

Conclusion: For alginate and addition silicone impression material, disinfection was achieved on exposure to UV rays for a period of 10 minutes. However, for polyether impression material 3 minutes of exposure to UV rays was sufficient to cause complete disinfection.

Keywords: Cross contamination; Disinfection; Infection control; Pathogenic.

[Table/Fig-1-12]:

(1) Alginate Impression. (2) Addition Silicone Impression. (3) Polyether Impression. (4) Use of sterile punch cutter for cutting samples. (5) Punch Sample. (6) UV Chamber. (7) Samples immersed in Ringers Solution after disinfection by various methods. (8) Turbidity observed over peptone water. (9) Pour Plate technique. (10) Digital colony counter. (11) Counting of colonies over digital colony counter. (12) Observation of colonies over culture plates – [i] Control group showing maximum colonies. [ii] 3 minutes of exposure to UV Rays. [iii] 6 minutes of exposure to UV Rays. [iv] 10 minutes of exposure to UV Rays. [v] 15 minutes of exposure to UV Rays. [vi] After immersion in 2% Glutaraldehyde solution for 10 minutes.