Digital vs. analog impression taking - which one is the safest in a post-Covid-19 world?

In a hygiene and safety-conscious industry, Covid-19 has pushed the subject even higher up the agenda. What does independent research tell us about digital and analog impression taking and dental hygiene and safety?

Read on below and find out what the 4 main lessons are.

1. With analog impressions your workflow needs extra steps, including material handling and transportation to the lab

Traditional impression techniques require handling multiple items, including the tray, chewing waxes, impression materials and any associated appliances. These handling factors are eliminated with digital impressions¹.

Conventional impressions/casts that are transferred to a lab involve transportation, which increases the risk of cross-infection^2,3 and can involve many hours in potentially humid conditions. Digital impressions with TRIOS do not require any physical transportation from clinic to the lab.

2. Conventional impressions can be challenging to disinfect, while digital scans require no disinfection

A wide variety of chemical solutions and techniques are recommended to disinfect impression materials ^4,5.

Getting the TRIOS ready for use includes thorough cleaning and disinfection between patients. This includes a strict protocol to clean and disinfect the scanner body and autoclaving the scanner tips to ensure proper disinfection between uses.

3. Conventional impression and cast handling between lab and clinic can increase cross-infection risks

Dental lab employees are at risk of infection from soiled impressions received from dental clinics. Contaminated items returned from dental labs to dental clinics can also become a source of cross-infection^6,7 .

Conventional impressions from clinics have to be disinfected by labs to ensure the set dental cast does not contain microorganisms, which can percolate within the material and remain viable for up to a week^8,9.

Using digital impressions significantly lowers the risk of cross-infection since there is no cast handling.

4. Manual creation of appliances/restorations increases contamination risks in the lab

Traditional production of dental restorations/appliances provides additional opportunities for contamination¹⁰. Therefore, they require disinfecting, which extends the processing time.

Digital design solutions require significantly reduced handling^11,12. Furthermore, increased automation in dental appliance production processes require little or no human intervention¹³.

References:

1. Barenghi L, Barenghi A, Cadeo C, Di Blasio A. Innovation by Computer-Aided Design/Computer-Aided Manufacturing Technology: A Look at Infection Prevention in Dental Settings. Biomed Res Int. 2019 Aug 6;2019:6092018.

2. Sofou A, Larsen T, Fiehn N. et al. Contamination level of alginate impressions arriving at a dental laboratory. Clin Oral Invest. 2002; 6, 161–165.

3. Vazquez-Rodrıguez I, Estany-Gestal A, Seoane-Romero J, Mora M, Varela-Centelles P, Santana-Mora U. Quality of cross-infection control in dental laboratories. A critical systematic review. Int. J Quality in Health Care. 2018: 30 (7):496–507.

4. Mushtaq MA, Khan MWU . An overview of dental impression disinfection techniques: a literature review. J Pak Dent Assoc 2018;27(4):207-12.

5. Chidambaranathan A, Balasubramanium M. Comprehensive Review and Comparison of the Disinfection Techniques Currently Available in the Literature. J Prosthodont. 2019;28(2):e849-e856.

6. Verran J, Kossar S, McCord JF. Microbiological study of selected risk areas in dental technology laboratories. J Dent. 1996; 24: 77-80.

7. Sykes LM, Said M, Ehlers M, Mateis SM, van Dyk C, Dullabh HD. Microbial contamination of denture polishing equipment. S. Afr. dent. j. 2019; 74(3): 116-122.

8. British Dental Association. Health Technical Memorandum 01-05: Decontamination in Primary Care Dental Practices. London: Department of Health; 2013

9. Sammy K, Benjamin S. Infection control mechanisms employed by dental laboratories to prevent infection of their dental technicians/technologists. J. Oral Health and Craniofacial Science 2016: 1 (1), :001–011.

10. Barker C.S, Sor, V, Dymock D. et al. Microbial contamination of laboratory constructed removable orthodontic appliances. Clin Oral Invest. 2014; 18, 2193–2202.

11. Suese K. Progress in digital dentistry: The practical use of intraoral scanners. Dent Mater J. 2020;39(1):52-56.

12. Ambili C, Prasad B. The era of future dentistry: Recent advances and future perspectives of restorative dentistry: A literature review. Int. J. Appl. Dent Sci. 2019; 5: 111-116.

13. Rekow ED. Digital dentistry: The new state of the art — Is it disruptive or destructive? Dent Mat: 2020; 36 (1): 9-24