{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T20:04:04Z","timestamp":1792008244525,"version":"4.4.0"},"reference-count":61,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2023,1,17]],"date-time":"2023-01-17T00:00:00Z","timestamp":1673913600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJERPH"],"abstract":"<jats:p>Due to permanent contact with bodily secretions such as blood and saliva, the dental workplace poses a high risk of infection for patients as well as for personnel. High-speed dental instruments are still considered one of the major hygienic risks, as the high-speed rotation of the attachments leads to the retraction of infectious material from patients\u2019 oral cavities. The aim of this study was to investigate the extent to which dental handpieces are contaminated after use. Spray-water samples were taken from different handpieces used in seven dental offices and protein concentrations were measured photometrically. In the first part of the study, samples were collected from each handpiece before and after the treatment of the patients. Additionally, the changes in protein concentration after consecutive treatments in which the same high-speed dental instrument was used were investigated. The results demonstrated measurable protein concentrations in 91.2% of a total of 398 samples, and 96.4% of the spray-water samples taken after treatment showed a discrepancy from the initial measured protein concentration. In 68.4% an increase in protein concentration was observed, whereas in 27.9% a decrease was measured. In conclusion, the internal contamination of high-speed dental instruments frequently occurs in daily usage and consequently may lead to the transmission of infectious agents by flushing the contaminated water out of the spray water tubes. Moreover, it must be pointed out that internal cleansing of handpieces is insufficient and that a final mechanical disinfection is indispensable.<\/jats:p>","DOI":"10.3390\/ijerph20031670","type":"journal-article","created":{"date-parts":[[2023,1,17]],"date-time":"2023-01-17T04:28:47Z","timestamp":1673929727000},"page":"1670","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["High-Speed Dental Instruments: An Investigation of Protein-Contaminated Dental Handpieces with the Bicinchoninic Acid Assay in Dental Offices in Styria, Austria"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0131-3968","authenticated-orcid":false,"given":"Michael","family":"Schalli","sequence":"first","affiliation":[{"name":"Department for Water-Hygiene and Micro-Ecology, D&R Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, 8010 Graz, Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Birgit","family":"Kogler","sequence":"additional","affiliation":[{"name":"Department for Water-Hygiene and Micro-Ecology, D&R Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, 8010 Graz, Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tillo","family":"Miorini","sequence":"additional","affiliation":[{"name":"Institute for Applied Hygiene, 8045 Graz, Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michael","family":"Gehrer","sequence":"additional","affiliation":[{"name":"Styrian Hospital Corporation KAGes, Hospital Leoben, 8700 Leoben, Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Franz F.","family":"Reinthaler","sequence":"additional","affiliation":[{"name":"Department for Water-Hygiene and Micro-Ecology, D&R Institute of Hygiene, Microbiology and Environmental Medicine, Medical University of Graz, 8010 Graz, Austria"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,1,17]]},"reference":[{"key":"ref_1","first-page":"152","article-title":"Effectiveness of ultrasonic cleaning of dental instruments","volume":"8","author":"Cafruny","year":"1995","journal-title":"Am. J. Dent."},{"key":"ref_2","first-page":"197","article-title":"Application of automated thermal disinfection instead of sterilisation procedures for treatment of rotating dental instruments: Efficacy against viruses?","volume":"200","author":"Rabenau","year":"1997","journal-title":"Zentralbl. Hyg. Umweltmed."},{"key":"ref_3","first-page":"528","article-title":"Microbial contamination of dental unit waterlines: Short- and long-term effects of flushing","volume":"42","author":"Santiago","year":"1994","journal-title":"Gen. Dent."},{"key":"ref_4","first-page":"72","article-title":"Hygienic processing of dental transmission instruments (handpieces and instruments, turbines) in dental practice","volume":"198","author":"Kunz","year":"1995","journal-title":"Zentralbl. Hyg. Umweltmed."},{"key":"ref_5","first-page":"369","article-title":"A new device for the disinfection of handpieces and turbines","volume":"44","author":"Petti","year":"1995","journal-title":"Minerva Stomatol."},{"key":"ref_6","first-page":"5720204","article-title":"Plasma Sterilization Effectively Reduces Bacterial Contamination in Dental Unit Waterlines","volume":"30","author":"Noopan","year":"2019","journal-title":"Int. J. Dent."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1016\/j.sdentj.2019.07.003","article-title":"Assessment of nosocomial bacterial contamination in dental unit waterlines: Impact of flushing","volume":"32","author":"Alkhulaifi","year":"2020","journal-title":"Saudi Dent. J."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"e12723","DOI":"10.7717\/peerj.12723","article-title":"Assessment of microbiota diversity in dental unit waterline contamination","volume":"10","author":"Dang","year":"2022","journal-title":"PeerJ"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1016\/j.jhin.2021.04.013","article-title":"Microbial contamination of dental unit water lines\u2014A matter of following instructions","volume":"113","author":"Claesson","year":"2021","journal-title":"J. Hosp. Infect."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1197","DOI":"10.3855\/jidc.13810","article-title":"Study of some risk factors for fungal contamination of dental unit waterlines in Alexandria, Egypt","volume":"15","author":"Omran","year":"2021","journal-title":"J. Infect. Dev. Ctries."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"001540","DOI":"10.1099\/jmm.0.001540","article-title":"Disinfection methods of dental unit waterlines contamination: A systematic review","volume":"71","author":"Wu","year":"2022","journal-title":"J. Med. Microbiol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"110728","DOI":"10.1016\/j.biopha.2020.110728","article-title":"Biological effects of Cannabidiol on normal human healthy cell populations: Systematic review of the literature","volume":"132","author":"Pagano","year":"2020","journal-title":"Biomed. Pharmacother."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"664","DOI":"10.1038\/sj.bdj.4800859a","article-title":"Occupational health\u2014Micorbial aerosols in general dental practice","volume":"189","author":"Benett","year":"2000","journal-title":"Br. Dent. J."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"670","DOI":"10.1080\/15428119591016683","article-title":"Characteristics of blood-containing aerosols generated by common powered dental equipment","volume":"56","author":"Miller","year":"1995","journal-title":"Am. Ind. Hyg. Assoc. J."},{"key":"ref_15","first-page":"87","article-title":"Assessing viral retention and elimination in rotary dental instruments","volume":"126","author":"Epstein","year":"1995","journal-title":"JADA"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1252","DOI":"10.1016\/0140-6736(92)92950-K","article-title":"Cross-contamination potential with dental equipment","volume":"340","author":"Lewis","year":"1992","journal-title":"Lancet"},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"401","DOI":"10.1128\/jcm.30.2.401-406.1992","article-title":"Cross-Infection Risks associated with current procedures for using high-speed dental handpieces","volume":"30","author":"Lewis","year":"1992","journal-title":"JCM"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1629","DOI":"10.1177\/00220345770560123601","article-title":"Laser evaluation of handpiece contamination","volume":"56","author":"Pelzner","year":"1977","journal-title":"J. Dent. Res."},{"key":"ref_19","first-page":"658","article-title":"Reduction of microbes in handpieces by flushing before use","volume":"105","author":"Scheid","year":"1982","journal-title":"JADA"},{"key":"ref_20","first-page":"59","article-title":"Bacteriological analysis of high-speed handpiece turbines","volume":"124","author":"Mills","year":"1993","journal-title":"JADA"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"359","DOI":"10.1016\/j.jhin.2008.12.005","article-title":"Evidence of aerosolised floating blood mist during oral surgery","volume":"71","author":"Ishihama","year":"2009","journal-title":"J. Hosp. Infect."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1427","DOI":"10.14219\/jada.archive.2000.0054","article-title":"The dental unit waterline controversy: Defusing the myths, defining the solution","volume":"131","author":"Mills","year":"2000","journal-title":"J. Am. Dent. Assoc."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Spagnolo, A.M., Sartini, M., and Cristina, M.L. (2020). Microbial Contamination of Dental Unit Waterlines and Potential Risk of Infection: A Narrative Review. Pathogens, 9.","DOI":"10.3390\/pathogens9080651"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1762040","DOI":"10.1080\/20002297.2020.1762040","article-title":"Dental aerosols: Microbial composition and spatial distribution","volume":"12","author":"Zemouri","year":"2020","journal-title":"J. Oral Microbiol."},{"key":"ref_25","first-page":"107","article-title":"Impact of self-ligating orthodontic brackets on dental biofilm and periodontal pathogens in adolescents","volume":"35","author":"Carli","year":"2021","journal-title":"J. Biol. Regul. Homeost. Agents"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"701","DOI":"10.1007\/s10529-020-03061-2","article-title":"Characterization and inhibition of four fungi producing citrinin in various culture media","volume":"43","author":"Gu","year":"2021","journal-title":"Biotechnol. Lett."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Schalli, M., Inwinkl, S.M., Platzer, S., Baumert, R., Reinthaler, F.F., Ofner-Kopeinig, P., and Haas, D. (2022). Cefsulodin and Vancomycin: A Supplement for Chromogenic Coliform Agar for Detection of Escherichia coli and Coliform Bacteria from Different Water Sources. Microorganisms, 10.","DOI":"10.3390\/microorganisms10122499"},{"key":"ref_28","unstructured":"(2018). Wasserbeschaffenheit\u2014Z\u00e4hlung von Legionellen. Standard No. \u00d6NORM EN ISO 11731."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1080\/08927014.2013.839782","article-title":"Dental handpiece contamination: A proteomics and surface analysis approach","volume":"30","author":"Smith","year":"2014","journal-title":"Biofouling"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"605","DOI":"10.1007\/s00784-010-0425-7","article-title":"Development of a validated process for manual preparation of dental transmission instruments","volume":"15","year":"2011","journal-title":"Clin. Oral Investig."},{"key":"ref_31","unstructured":"(2006). Washer-disinfectors\u2014Part 1: General requirements, terms and definitions and tests. Standard No. DIN EN 15883-1."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"227","DOI":"10.5344\/ajev.2014.14076","article-title":"Advantages of the KDS\/BCA Assay over the Bradford Assay for Protein Quantification in White Wine and Grape Juice","volume":"66","author":"Gazzola","year":"2014","journal-title":"Am. J. Enol. Vitic."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1016\/0003-2697(85)90442-7","article-title":"Measurement of protein using bicinchoninic acid","volume":"150","author":"Smith","year":"1985","journal-title":"Anal. Biochem."},{"key":"ref_34","unstructured":"Schwirzer, S. (1998). Entwicklung Eines Biologischen Verfahrens zur Bestimmung von 2,3,7,8-TCDD \u00c4quivalenzwerten in Umweltrelevanten Matrizes unter Einbeziehung chemischer Clean-Up Schritte, Herbert Utz Verlag."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1007\/978-1-4939-8793-1_3","article-title":"Measuring Protein Concentration with Absorbance, Lowry, Bradford Coomassie Blue, or the Smith Bicinchoninic Acid Assay Before Electrophoresis","volume":"1855","author":"Goldring","year":"2019","journal-title":"Methods Mol. Biol."},{"key":"ref_36","first-page":"569","article-title":"Infection control\u2014Its evolution to the current standard precautions","volume":"134","author":"Molinari","year":"2003","journal-title":"JADA"},{"key":"ref_37","first-page":"123","article-title":"Control of cross-contamination","volume":"85","author":"Neugeboren","year":"1972","journal-title":"JADA"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"103746","DOI":"10.1016\/j.jdent.2021.103746","article-title":"The effect of high-speed dental handpiece coolant delivery and design on aerosol and droplet production","volume":"112","author":"Allison","year":"2021","journal-title":"J. Dent."},{"key":"ref_39","first-page":"130","article-title":"High speed handpieces","volume":"6","author":"Bhandary","year":"2014","journal-title":"J. Int. Oral Health"},{"key":"ref_40","first-page":"389","article-title":"Cross-infection risks associated with high-speed dental handpieces","volume":"48","author":"Hauman","year":"1993","journal-title":"J. Dent. Assoc. S. Afr."},{"key":"ref_41","first-page":"109","article-title":"Efficacy of acoustic waves in preventing Streptococcus mutans adhesion on dental unit water line","volume":"31","author":"Pantanella","year":"2019","journal-title":"Ann. Ig"},{"key":"ref_42","first-page":"3","article-title":"Kontamination und Aufbereitung zahn\u00e4rztlicher \u00dcbertragungsinstrumente sowie rotierender Instrumente","volume":"15","author":"Michels","year":"2009","journal-title":"Aseptica\u2014Fachmag. Krankenh. Prax."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Matys, J., and Grzech-Le\u015bniak, K. (2020). Dental Aerosol as a Hazard Risk for Dental Workers. Materials, 13.","DOI":"10.3390\/ma13225109"},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Senpuku, H., Fukumoto, M., Uchiyama, T., Taguchi, C., Suzuki, I., and Arikawa, K. (2021). Effects of Extraoral Suction on Droplets and Aerosols for Infection Control Practices. Dent. J., 9.","DOI":"10.3390\/dj9070080"},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Han, P., Li, H., Walsh, L.J., and Ivanovski, S. (2021). Splatters and Aerosols Contamination in Dental Aerosol Generating Procedures. Appl. Sci., 11.","DOI":"10.3390\/app11041914"},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Rosa, V., Agarwalla, S.V., Tan, B.L., Choo, S.Y., Sim, Y.F., Boey, F.Y.C., Anantharaman, S., Duggal, M.S., and Tan, K.S. (2022). Pandemic Preparedness and Response: A Foldable Tent to Safely Remove Contaminated Dental Aerosols\u2014Clinical Study and Patient Experience. Appl. Sci., 12.","DOI":"10.3390\/app12157409"},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Engsomboon, N., Pachimsawat, P., and Thanathornwong, B. (2022). Comparative Dissemination of Aerosol and Splatter Using Suction Device during Ultrasonic Scaling: A Pilot Study. Dent. J., 10.","DOI":"10.3390\/dj10080142"},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"103556","DOI":"10.1016\/j.jdent.2020.103556","article-title":"A systematic review of droplet and aerosol generation in dentistry","volume":"105","author":"Innes","year":"2021","journal-title":"J. Dent."},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Takenaka, S., Sotozono, M., Yashiro, A., Saito, R., Kornsombut, N., Naksagoon, T., Nagata, R., Ida, T., Edanami, N., and Noiri, Y. (2022). Efficacy of Combining an Extraoral High-Volume Evacuator with Preprocedural Mouth Rinsing in Reducing Aerosol Contamination Produced by Ultrasonic Scaling. Int. J. Environ. Res. Public Health, 19.","DOI":"10.3390\/ijerph19106048"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"2863","DOI":"10.1007\/s00784-021-04265-0","article-title":"Reduction of aerosols and splatter generated during ultrasonic scaling by adding food-grade thickeners to coolants: An in-vitro study","volume":"26","author":"Farah","year":"2022","journal-title":"Clin. Oral Investig."},{"key":"ref_51","first-page":"324","article-title":"Eigenschaften von Blut und Einfluss auf die Reinigung","volume":"12","author":"Michels","year":"2004","journal-title":"Zentralsterilisation"},{"key":"ref_52","doi-asserted-by":"crossref","first-page":"239","DOI":"10.1016\/j.jpor.2019.07.013","article-title":"Autoclave sterilization of dental handpieces: A literature review","volume":"64","author":"Sasaki","year":"2020","journal-title":"J. Prosthodont Res."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"61","DOI":"10.1016\/j.jhin.2021.05.013","article-title":"The devil is in the validation and design; managing the risk from opportunistic pathogens in the dental unit","volume":"114","author":"Smith","year":"2021","journal-title":"J. Hosp. Infect."},{"key":"ref_54","first-page":"1301","article-title":"Performance of high-speed dental handpieces subjected to simulated clinical use in sterilization","volume":"130","author":"Leonard","year":"1999","journal-title":"ADA"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.jhin.2003.09.006","article-title":"Problems with the decontamination of dental handpieces and other intra-oral dental equipment in hospitals","volume":"56","author":"Weightman","year":"2004","journal-title":"J. Hosp. Infect."},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"442","DOI":"10.3389\/fcimb.2018.00442","article-title":"The Oral Microbiome in the Elderly With Dental Caries and Health","volume":"8","author":"Jiang","year":"2019","journal-title":"Front. Cell. Infect. Microbiol."},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"761","DOI":"10.1016\/j.watres.2017.07.019","article-title":"An experimental study on the influence of water stagnation and temperature change on water quality in a full-scale domestic drinking water system","volume":"123","author":"Vreeburg","year":"2017","journal-title":"Water Res."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"e0199429","DOI":"10.1371\/journal.pone.0199429","article-title":"Impact of stagnation and sampling volume on water microbial quality monitoring in large buildings","volume":"13","year":"2018","journal-title":"PLoS ONE"},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"110648","DOI":"10.1016\/j.envres.2020.110648","article-title":"Changes in biofilm composition and microbial water quality in drinking water distribution systems by temperature increase induced through thermal energy recovery","volume":"194","author":"Ahmad","year":"2021","journal-title":"Environ. Res."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"140","DOI":"10.2334\/josnusd.17-0387","article-title":"Effect of water temperature during ultrasonic denture cleaning","volume":"61","author":"Iwawaki","year":"2019","journal-title":"J. Oral Sci."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"8954","DOI":"10.1021\/acs.est.6b00835","article-title":"Understanding, Monitoring, and Controlling Biofilm Growth in Drinking Water Distribution Systems","volume":"50","author":"Liu","year":"2016","journal-title":"Environ. Sci. Technol."}],"container-title":["International Journal of Environmental Research and Public Health"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1660-4601\/20\/3\/1670\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T18:08:03Z","timestamp":1760119683000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1660-4601\/20\/3\/1670"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,1,17]]},"references-count":61,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2023,2]]}},"alternative-id":["ijerph20031670"],"URL":"https:\/\/doi.org\/10.3390\/ijerph20031670","relation":{},"ISSN":["1660-4601"],"issn-type":[{"value":"1660-4601","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,1,17]]}}}