|Year : 2021 | Volume
| Issue : 9 | Page : 1313-1320
Evaluating the Efficacy of Chemical Disinfectants on Contaminated Dental Materials Contaminated by An Airborne Disease Tuberculosis Similar to COVID-19
B Karaman1, A Balık1, ED Cifter1, A Balıkcı2, G Ozenen3, D Ozdemir-Ozenen4, M Ozdemir-Karatas1
1 Department of Prosthodontics, Faculty of Dentistry, Istanbul University, Istanbul, Turkey
2 Clinic of Chest Diseases, Sureyyapasa Chest Diseases and Chest Surgery Training and Research Hospital, University of Health Sciences, Istanbul, Turkey
3 Department of Architecture, Faculty of Fine Arts and Design, Dogus University, Istanbul, Turkey
4 Department of Pediatric Dentistry, Faculty of Dentistry, Yeditepe University, Bagdat, Turkey
|Date of Submission||22-Sep-2020|
|Date of Acceptance||19-Jan-2021|
|Date of Web Publication||16-Sep-2021|
Dr. M Ozdemir-Karatas
Department of Prosthodontics, Faculty of Dentistry, Istanbul University, Topkapi Mahallesi, Turgut Ozal Millet Cd, Capa, Fatih, Istanbul - 34093
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Background: Tuberculosis (TB) is a communicable disease as well as an airborne disease. Mycobacterium tuberculosis (MTB) could survive on dental materials shipped to dental laboratories. Aims: The aim of this study was to determine the number of bacilli held on the prosthetic material and the effect of chemical disinfection agents on various prosthetic materials that were shipped to dental laboratory of TB patient. Materials and Methods: The study consisted of three study groups, and a control group. 10 mm x 2 mm disc-shaped (n = 18 for each group, n = 72 in total) nickel-chromium alloy (Ni-Cr), polymethylmethacrylate (PMMA), and dental ceramic (DC) samples were prepared. After exposure to MTB 24 hours in a 37°C incubator, six samples for each group (PMMA), Ni-Cr alloy and a control group DC samples) were exposed to three disinfectants; 10 minutes into 2% glutaraldehyde, 10 minutes into 5% sodium hypochlorite, and 1 minute into alcohol-based disinfectant after vortexed in distilled water. Colony forming units (CFU/ml) were calculated per milliliters. Two-way ANOVA statistical analysis method was used, and a P value less than 0.05 was considered as significant. Results: The bacteria count for six Ni-Cr alloy disc-shaped specimens were recorded as 40, 10, 8, 6, 5, and 4 CFU/ml, respectively. Intensity of the colonies were found to be lower in other groups. 5 CFU/ml were detected on a single PMMA sample in the control group, and 40 CFU/ml were detected on one of the dental ceramic sample. No MTB uptake was observed on any sample in the 2% glutaraldehyde and 5% NaOCl disinfectant study groups. In alcohol-based disinfectant group, 1 CFU/ml was observed on Ni-Cr alloy sample. The effect of prosthetic materials used in this experimental study were not statistically significant on the CFU (p = 0.293). However, the disinfectants use was statistically significant on the number of colonies (p = 0.004). Conclusion: NaOCl and glutaraldehyde appeared to be more effective than alcohol-based disinfectant in removing MTB from Ni-Cr alloy, PMMA and dental ceramic surfaces.
Keywords: Airborne disease, dental materials, disinfection, tuberculosis
|How to cite this article:|
Karaman B, Balık A, Cifter E D, Balıkcı A, Ozenen G, Ozdemir-Ozenen D, Ozdemir-Karatas M. Evaluating the Efficacy of Chemical Disinfectants on Contaminated Dental Materials Contaminated by An Airborne Disease Tuberculosis Similar to COVID-19. Niger J Clin Pract 2021;24:1313-20
|How to cite this URL:|
Karaman B, Balık A, Cifter E D, Balıkcı A, Ozenen G, Ozdemir-Ozenen D, Ozdemir-Karatas M. Evaluating the Efficacy of Chemical Disinfectants on Contaminated Dental Materials Contaminated by An Airborne Disease Tuberculosis Similar to COVID-19. Niger J Clin Pract [serial online] 2021 [cited 2022 Nov 29];24:1313-20. Available from: https://www.njcponline.com/text.asp?2021/24/9/1313/325919
| Introduction|| |
The oldest existing human pathogen; tuberculosis (TB) bacillus is named as Mycobacterium tuberculosis (MTB), and typically affects the lungs (pulmonary TB) but can also affect the other sites as well (extrapulmonary TB). World's Health Organization (WHO) has declared the TB as one of the top ten causes of mortality while a quarter of the world's population is currently being infected with MTB. The lifetime risk is known as 5–10%.,,
TB is a communicable disease characterized by airborne or spreading aerosols during talking, coughing, or sneezing just like the novel Coronovirus Disease COVID-19. MTB are approximately 1-5 μm in size and remain suspended in air for hours in the environment. The possibility of contagion of a person exposed to MTB to be infected depends on the concentration of infectious droplets in the air, the time spent in this area, inadequate ventilation, and poor health status of the exposed person.,
Although contamination is aerogenic, detecting the MTB infection, polymerase chain reaction is a rapid and simple diagnostic system that can be made not only with mixed saliva, but also with dental plaque, caries lesions, and denture plaque.
The clinical symptoms of active tuberculosis are persistent cough, night sweats, weight loss, fever, and anorexia.,,, As these symptoms are nonspecific, initial diagnosis is generally bronchitis. If the symptoms are persistent than they are tested for TB. An alarming sign is hemoptysis, which requires to be diagnosed with an X-ray of the thorax. During this period of time, the contamination cannot be avoided unless necessary measures are not taken into consideration.
The mortality rate from TB disease is high without treatment. The Word Health Organization (WHO) recommends treatment with a 6-month regimen of four first-line medication. Multidrug-resistant TB and extensive drug-resistant TB are forms of TB that have become increasingly prominent in recent years and complicate the treatment of this disease.,,
TB patients with resistance to recommended drug regimen might be provided with alternative treatments potentially involving newer drugs. The only licensed vaccine for prevention of TB disease is the bacilli Calmette-Guérin (BCG) vaccine for children. Currently, no vaccine is present for adults to prevent TB disease.
According to the “Tuberculosis surveillance and monitoring report in Europe 2020” almost 15.78 cases per 100,000 of the population is known to be TB positive in Turkey in 2018. WHO reported that this highly contagious disease mostly seen in South-East Asia (44%), Africa (24%) and the Western Pacific (18%), with smaller percentages in the Eastern Mediterranean (8%), the Americas (3%) and Europe (3%) in 2018.
It is therefore crucial for oral care practitioner to prepare an infection control plan including the dentist, dental hygienist, dental assistant as well as the dental technicians. This plan should include an administrative check, an environmental check, and an airway protection check.,, During the treatment, oral health care practitioners must put on strong filtering face masks, such as N95, N99, or N100.,,,, Office rooms should be cleaned thoroughly with tuberculocidal disinfectants, especially after the visits of patients with active TB, as MTB can survive on the uncovered surfaces and in dust for a long time. Dental tools used during treatment should also be disinfected and autoclaved in the usual way., MTB could survive on dental materials shipped to dental laboratories and could lead the dental technicians at risk unless the necessary precautions are not taken. Cross-contamination of the airborne diseases has been already reported in numerous studies. More than 60% of the materials shipped to dental laboratories from clinics are recorded to be contaminated with pathogenic microorganisms. These precautions are all very crucial for the airborne diseases transmitted through aerosols including COVID-19.,
The aim of this study was determination of the number of bacilli held on the dental prosthetic materials, and the effect of chemical disinfection agents on various dental prosthetic materials that were shipped to dental laboratories during the obligatory dental interventions of TB patient. There is no existing literature addressing the effectiveness of disinfection methods in dental prosthetic materials contaminated with MTB. The null hypothesis of this study was determined as “Disinfection methods tested in this study present similar antibacterial effect on MTB involvement in prosthetic materials.”
| Materials and Methods|| |
Three different materials are tested in this present study. These materials are nickel-chromium alloy (Ni-Cr) (Meto-A, Metodentalitl.ih travelers. Industry and Trade Co. Ltd., Turkey), polymethylmethacrylate (PMMA) (Meliodent®, Heraeus Kulzer GmbH & Co. KG, Hanau, Germany), and dental ceramic (DC) (VITA VMK Master®, H. Rauter GmbH & Co., Germany). Four experimental groups were designed for this experiment from the materials described above and the fourth group which serving as the control group. Disc-shaped specimens were prepared for each group with a sample size of 10 mm x 2 mm (n = 18 for each group, n = 72 in total) as following the manufacturer guidelines.
Tuberculosis solution was prepared in the microbiology Ministry of Health labs (Istanbul Provincial Health Directorate, Istanbul Sureyyapasa Chest Diseases and Thoracic Surgery Training and Research Hospital) using H37 standard strain test organism at 0.5 McFarland standard (108 CFU/mL) in a 50 mL Eppendorf tube in a Class 2 biosafety cabinet.
The samples were vortexed for 10 seconds in sterile tubes to be contaminated. Then, they were preserved in tuberculosis solution for 24 hours in a 37°C incubator (TK-SCAN Diomed Inc., Istanbul, Turkey) to ensure microorganism growth. Inoculation was performed on a Lowenstein-Jensen (LJ) medium for growth control. Incubation is observed in the medium.
2% glutaraldehyde (Mooncid®; DoganaySan.Tic.Ltd.Şti Chemistry, Istanbul, Turkey), 5% sodium hypochlorite (NaOCl) (Wizard; Chemistry Guide, Istanbul, Turkey), and alcohol-based disinfectant (100 g contains: 25 g ethanol (94%), 35 g 1-propan-ol, Liquid Mikrozid® AF Schülke& Mayr GmbH, Norderstedt, Germany) were used in the study as disinfectant agents. Six samples from each group ((PMMA), Ni-Cr alloy and a control group DC samples) were exposed to these three disinfectants after the incubation. All samples were vortexed in distilled water before the disinfection procedure.
The control group was referenced to evaluate the effectiveness of washing only with water for removing tuberculosis bacilli from the prosthetic material. Control group samples were taken into sterile tubes filled with distilled water with 1000 μl micropipettes with the help of sterile forceps. These tubes were then vortexed, allowing the bacteria on the sample surface to pass into distilled water. The liquid sample taken from the tube was inoculated into LJ medium. This procedure was applied to all study groups.
In the first study group, the effectiveness of 2% glutaraldehyde disinfectant in removing tuberculosis bacilli on the dental prosthetic material was tested. Samples were vortexed as in the control group. Then the samples were immersed in 2% glutaraldehyde disinfectant containing tubes and kept for 10 minutes to ensure that all surfaces would be in contact with the disinfectant. Samples were immersed in distilled water after this application to prevent the LJ medium being affected by the presence of glutaraldehyde. They were removed from distilled water by sterile forceps and taken into sterile tubes filled with distilled water by 1000 μl micropipettes. These tubes were vortexed, allowing the bacteria on the sample surface to be released into distilled water. This solution was inoculated into LJ medium.
In the second study group, the effectiveness of 5% NaOCl disinfectant in removing tuberculosis bacilli on dental prosthetic material was studied. Samples were vortexed as in control group. The samples were immersed in tubes containing 5% NaOCl disinfectant and kept for 10 minutes to ensure all surfaces would be in contact with the disinfectant. Then the samples were immersed in distilled water to eliminate the effect of NaOCl disinfectant on LJ medium. They were removed from distilled water by sterile forceps and were taken into sterile tubes filled with distilled water by 1000 μl micropipettes. These tubes were vortexed, allowing the bacteria on the sample surface to release into distilled water. The cultivation of the sample was made on the LJ medium.
In the third study group, the effectiveness of alcohol-based disinfectant in removing tuberculosis bacilli remained on the dental prosthetic material was tested. The procedures applied to the samples were same as for other disinfectants. However, the samples were kept for 1 minute in the alcohol-based disinfectant after being vortexed in distilled water. Samples were immersed in distilled water again following this application so that the LJ medium was not affected by the presence of alcohol. They were removed from distilled water by sterile forceps and taken into sterile tubes filled with distilled water by 1000 μl micropipettes. These tubes were vortexed, allowing the bacteria on the sample surface to release into distilled water. This liquid was taken with micropipettes and inoculated into LJ medium.
After the cultivation was completed, the tubes were kept in an incubator at 37°C for 52 days to ensure the incubation was set. Colony forming units (CFU/ml) were calculated per milliliters after the dwell time was completed. Preparation of the samples were shown in [Figure 1] and flowchart of the whole procedure was given in [Figure 2].
|Figure 1: (a) Preparation of the samples; (b) The samples immersed in distilled water; (c) The liquid sample containing bacteria in Lowenstein-Jensen medium; (d) Colonies observed in the samples after the dwell time was completed|
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|Figure 2: Flowchart of the procedure. TB: Tuberculosis, °C: The degree Celcius, Ni-Cr: Nickel-Chromium alloy, PMMA: Polymethylmethacrylate, DC: Dental ceramic, NaOCl: Sodium hypochlorite, LJ: Lowenstein-Jensen|
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The sample size calculation was performed prior to the study as indicated a minimum of 18 specimens for each group as the power analysis revealed 80.69% with a 95% confidence interval. IBM SPSS Statistics V23 software program was used to analyze the data collected through these experiments. The number of colonies were determined based on the bacterial colonies counted on the material as a result of MTB uptake. Each colony contained approximately 108 CFU/ml bacilli. Two-way ANOVA statistical analysis method was used to assess the effect of the colony number disinfection process on various prosthetic materials. Differences were noted with a significance level of P < 0.05.
| Results|| |
Colony forming units per mililiters (CFU/ml) of the samples were shown in [Table 1]. In control group, bacterial involvement in each dental prosthetic material was observed. The bacteria count for six Ni-Cr alloy samples was detected as 40, 10, 8, 6, 5, and 4 CFU/ml respectively. Intensities of the colonies were determined to be lower in other groups. 5 CFU/ml of bacteria count were detected on a single PMMA sample in the control group, and 40 CFU/ml were detected on one of the dental ceramic samples.
|Table 1: Bacteria colony forming units per milliliters (CFU/ml) detected for each sample of dental prosthetic material using various disinfection solutions|
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The data of the study groups revealed no MTB uptake was observed on any sample in the 2% glutaraldehyde and 5% NaOCl disinfectant study groups. In the third study group with alcohol-based disinfectant, 1 CFU/ml of bacteria count was observed on Ni-Cr alloy.
Statistical analysis of the effect of disinfectants on the colony counts on the materials were shown in [Table 2]. The effect of prosthetic materials used in this experimental study was not statistically significant on the CFU (p = 0.293). However, the disinfectants use was statistically significant on the number of colonies (p = 0.004).
|Table 2: Bacteria colony forming units per milliliters (CFU/ml) detected for different dental prosthetic materials using various disinfection solutions|
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Increased bacteria forming colonies were observed in especially Ni-Cr subgroup of the control group compared to the study groups. This is an indication that washing only will not be sufficient to remove the bacteria from the prosthetic material. The interaction of prosthetic material and disinfectant within the study was not statistically significant (p = 0.293).
| Discussion|| |
Although some viral/bacterial diseases and viruses as Anthrax, Aspergillosis, Blastomycosis, Chickenpox, Adenovirus, Enteroviruses, Rotavirus, Influenza, Rhinovirus, Neisseria More Details meningitidis, Streptococcus pneumoniae, Legionellosis, Measles, Mumps, Smallpox, Cryptococcosis, Tuberculosis, Bordetella pertussis, Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory Syndrome (MERS), and the novel Coronavirus Disease- 2019 (COVID-19) are some of the common pathogens that may spread via airborne transmission, the most recent COVID-19 pandemic has pointed out the importance of infectious diseases spreading as airborne, since this is a dramatically lethal disease,,, While these infectious diseases are highly crucial and noteworthy, TB rate has remained high in Turkey compared to the other countries during the last decade. And oral care providers are at increased risk of coming into contact with TB in their practice offices., All existing evidence and trends in infectious diseases led us to focus on TB throughout this study.
Despite MTB is known to be an airborne decease, it also existed in saliva that can cause dental tools and materials highly contagious for the dental practitioners and staff at dental laboratories. Dental impressions, maxillomandibular registration bases and apparatus, crowns, and bridge restoration, and prostheses are all exposed to contamination in the patient's mouth. Ni-Cr alloy, PMMA, and DC were investigated in the current study as they are the most common materials used in fabrication of prostheses shipped to dental laboratories. The existence of pathogenic microorganisms on the materials shipped to dental laboratories demonstrated by several studies.,,, The guidelines for the prevention from infections in dental offices exist. The American Dental Association (ADA) and Centers for Disease Control and Prevention (CDC) guidelines recommend dental prostheses to be disinfected before being shipped to the laboratory and before delivery to the patient., Although numerous studies were conducted with disinfection of dental impression materials,,,,, there is no existing study on the disinfection of dental prosthetic materials contaminated with MTB.
ADA recommends that dental metal crowns should immerse in glutaraldehyde, wherever removable dentures (metal, acrylic, dental ceramic) in iodophors or chlorine compounds to avoid contamination. Therefore, glutaraldehyde and sodium hypochlorite were included in the current study due to the efficiency on TB, and alcohol-based disinfectant with its ease in access in dental practice.
Because of the bactericidal and sporozoite impact, regardless of presence of organic residues, 2% glutaraldehyde solution could be used in the disinfection of instruments that cannot be sterilized. However, it should be used carefully since it could be irritating in contact with the skin. In a previous study on the disinfection of various tuberculosis types, it was stated that 2% glutaraldehyde solution should be applied for more than 10 minutes in order to achieve the effect of 2% glutaraldehyde in the presence of sputum. However, our study is an in-vitro study and since there is no sputum on the samples, the application of 2% glutaraldehyde for 10 minutes in line with the company's recommendation was found effective on all materials.
American Dental Association also recommends using sodium hypochlorite as a denture cleaning and disinfecting agent. Although sodium hypochlorite has disadvantages such as unpleasant odor, the possibility of change in color of acrylic resin, and a corrosive effect on metal alloys, it appears to be effective in disinfection procedure of most of the dental materials.,
Alcohol-based disinfectant is effective in decontaminating any surface within two minutes of application, destroying a wide range of micro-organisms like Methicillin-resistant Staphylococcus aureus and Human Immunodeficiency Virus. This disinfectant appeared be more effective to Candida auris than Candida albicans, recently. A previous study concluded that glutaraldehyde and sodium hypochlorite have comparable microbiocidal activity on impression materials. Another study conducted on impression materials was concluded that alcohol-based spray disinfectant was less effective than either NaOCl or glutaraldehyde. The study performed with povidine-iodine, NaOCl, glutaraldehyde, peracetic acid (as immersion) and isopropyl alcohol (as spray) were in line with the previous study that glutaraldehyde, and NaOCl have similar antimicrobial effects whereas isopropyl alcohol was less effective to Staphylococcus aureus, Streptococcus viridans, Streptococcus mutans, Streptococcus feacalis, Streptococcus pneumonia, Streptococcus Group A, Staphylococcus albus, Pseudomonas aeruginosa, Escherichia More Details coli, Lactobacillus, Candida albicans, Diptheroids, Klebsiella pneumoniae on impression materials. The key findings of this present experimental study showed that alcohol-based disinfectant found to be less effective than glutaraldehyde and NaOCl to MTB, consistent with existing literature.
A systematic review showed that every disinfectant was responsible of the surface alterations on PMMA prostheses in all studies. Not only surface roughness but also color of PMMA prostheses was affected by chemical disinfection solution.,, The physical properties of the material as their surface roughness after disinfection procedure was not evaluated in this present study. Further research is needed on the extent of the disinfection period in the presence of sputum; and, examining its effects on the physical properties of prosthetic materials.
Chemical disinfectants can be applied either by the spraying or the immersion technique. Spraying is more hazardous for the dentist and dental office workers because of the exposure with these chemical disinfectants and may cause spreading of airborne disease. Furthermore, the immersion techniques are more effective in reaching all the surfaces and will be safer in the presence of an airborne disease.,,, Both spraying and immersion techniques are effective in disinfection, however, immersion technique was utilized in this experimental study to prevent the contamination possibility of tuberculosis.
This study has further shown that MTB adhesion have detected on all Ni-Cr alloy samples whereas it is just observed in one sample of dental ceramic and PMMA. This study also highlights that disinfecting with water may not be insufficient in achieving desired outcomes. Nevertheless, all disinfection procedures with the exception of alcohol-based disinfectants appeared to remove TB bacilli from the surface of the samples, although the results were not statistically significant. Finally, this study was an in vitro study containing polished samples, but dental prostheses may have retentive, rough surfaces, therefore in vivo studies are recommended. The findings of this study highlight polished surfaces Ni-Cr alloy surfaces were more absorbent than PMMA and dental ceramic as disinfectants were effective in all samples under all scenarios.
| Conclusion|| |
The findings of this present experimental study show that MTB could not be fully eliminated from dental prosthetic materials just by washing with water. It is declared that a chemical agent should be used for disinfection after the removal of organic residues. This study also reveals that the disinfectants containing NaOCl, and glutaraldehyde were more effective than alcohol-based disinfectant in eliminating MTB from Ni-Cr alloy, PMMA, and dental ceramic surfaces.
Based on the findings of this present study, a thoroughly designed disinfection approach should be performed for all the dental prostheses which will be shipped to the dental laboratories.
The authors wish to thank Zeynal Karaca for his assistance in editing this manuscript.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Petti S. Tuberculosis: Occupational risk among dental healthcare workers and risk for infection among dental patients. A meta-narrative review. J Dent 2016;49:1-8.
Burger MS, Abraham-Inpijn L, Vissink A. Tuberculose in de tandartspraktijk. Epidemiologie, klinisch beeld en preventie [Tuberculosis in the dental office. Epidemiology, clinical view and prevention]. Ned Tijdschr Tandheelkd 2012;119:175-82. Dutch.
Eguchi J, Ishihara K, Watanabe A, Fukumoto Y, Okuda K. PCR method is essential for detecting Mycobacterium tuberculosis in oral cavity samples. Oral Microbiol Immunol 2003;18:156-9.
Porteous NB, Terezhalmy GT. Tuberculosis: Infection control/exposure control issues for oral healthcare workers. J Contemp Dent Pract 2008;9:1-13.
Dheda K, Barry CE 3rd
, Maartens G. Tuberculosis. Lancet 2016;387:1211-26.
Cleveland JL, Robison VA, Panlilio AL. Tuberculosis epidemiology, diagnosis and infection control recommendations for dental settings: An update on the Centers for Disease Control and Prevention guidelines. J Am Dent Assoc 2009;140:1092-9.
Singh A, Prasad R, Gupta A, Das K, Gupta N. Severe acute respiratory syndrome coronavirus-2 and pulmonary tuberculosis: Convergence can be fatal. Monaldi Arch Chest Dis 2020;90. doi: 10.4081/monaldi.2020.1368.
Infection control recommendations for the dental office and the dental laboratory. ADA Council on Scientific Affairs and ADA Council on Dental Practice. J Am Dent Assoc 1996;127:672-80.
Thomas MV, Jarboe G, Frazer RQ. Infection control in the dental office. Dent Clin North Am 2008;52:609-28.
Vázquez-Rodríguez I, Estany-Gestal A, Seoane-Romero J, Mora MJ, Varela-Centelles P, Santana-Mora U. Quality of cross-infection control in dental laboratories. A critical systematic review. Int J Qual Health Care 2018;30:496-507.
Gupta S, Rani S, Garg S. Infection control knowledge and practice: A cross-sectional survey on dental laboratories in dental institutes of North India. J Indian Prosthodont Soc 2017;17:348-54.
] [Full text]
Jamal M, Shah M, Almarzooqi SH, Aber H, Khawaja S, El Abed R, et al
. Overview of transnational recommendations for COVID-19 transmission control in dental care settings. Oral Dis 2020. doi: 10.1111/odi.13431.
Shereen MA, Khan S, Kazmi A, Bashir N, Siddique R. COVID-19 infection: Origin, transmission, and characteristics of human coronaviruses. J Adv Res 2020;24:91-8.
Ather B, Mirza TM, Edemekong PF. Airborne Precautions. 2020. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2020.
Harte JA. Looking inside the 2003 CDC dental infection control guidelines. J Calif Dent Assoc 2004;32:919-30.
Connor C. Cross-contamination control in prosthodontic practice. Int J Prosthodont 1991;4:337-44.
Wakefield CW. Laboratory contamination of dental prostheses. J Prosthet Dent 1980;44:143-6.
Agostinho AM, Miyoshi PR, Gnoatto N, ParanhosHde F, Figueiredo LC, Salvador SL. Cross-contamination in the dental laboratory through the polishing procedure of complete dentures. Braz Dent J 2004;15:138-43.
Williams DW, Chamary N, Lewis MA, Milward PJ, McAndrew R. Microbial contamination of removable prosthodontic appliances from laboratories and impact of clinical storage. Br Dent J 2011;211:163-6.
Volgenant CMC, Persoon IF, de Ruijter RAG, de Soet JJH. Infection control in dental health care during and after the SARS-CoV-2 outbreak. Oral Dis 2020. doi: 10.1111/odi.13408.
Centers for Disease Control and Prevention. Summary of Infection Prevention Practices in Dental Settings: Basic Expectations for Safe Care. Atlanta, GA: Centers for Disease Control and Prevention, US Dept of Health and Human Services; October 2016, Centers for Disease Control and Prevention. Guidelines for Infection Control in Dental Health-Care Settings — 2003. MMWR 2003;6-15.
Infection control recommendations for the dental office and the dental laboratory. Council on Dental Materials, Instruments, and Equipment. Council on Dental Practice. Council on Dental Therapeutics. J Am Dent Assoc 1988;116:241-8.
Fernandes FH, Orsi IA, Villabona CA. Effects of the peracetic acid and sodium hypochlorite on the colour stability and surface roughness of the denture base acrylic resins polymerised by microwave and water bath methods. Gerodontology 2013;30:18-25.
Asopa SJ, Padiyar UN, Verma S, Suri P, Somayaji NS, Radhakrishnan IC. Effect of heat sterilization and chemical method of sterilization on the polyvinyl siloxane impression material. A comparative study. J Family Med Prim Care 2020;9:1348-53. [Full text]
Al Shikh A, Milosevic A. Effectiveness of alcohol and aldehyde spray disinfectants on dental impressions. Clin Cosmet Investig Dent 2020;12:25-30.
Azevedo MJ, Correia I, Portela A, Sampaio-Maia B. A simple and effective method for addition silicone impression disinfection. J Adv Prosthodont 2019;11:155-61.
Savabi O, Nejatidanesh F, Bagheri KP, Karimi L, Savabi G. Prevention of cross-contamination risk by disinfection of irreversible hydrocolloid impression materials with ozonated water. Int J Prev Med 2018;9:37.
] [Full text]
Choudhury GK, Chitumalla R, Manual L, Rajalbandi SK, Chauhan MS, Talukdar P. Disinfectant efficacy of 0.525% sodium hypochlorite and epimax on alginate impression material. J Contemp Dent Pract 2018;19:113-6.
Jensen PA, Lambert LA, Iademarco MF, Ridzon R. CDC. Guidelines for preventing the transmission of Mycobacterium tuberculosis in health-care settings 2005. MMWR Recomm Rep 2005;54:1-141.
Best M, Sattar SA, Springthorpe VS, Kennedy ME. Efficacies of selected disinfectants against Mycobacterium tuberculosis. J Clin Microbiol 1990;28:2234-9.
Badaró MM, Bueno FL, Arnez RM, Oliveira VC, Macedo AP, de Souza RF, et al
. The effects of three disinfection protocols on Candida spp., denture stomatitis, and biofilm: A parallel group randomized controlled trial. J Prosthet Dent 2020:124:690-8.
Salles MM, Oliveira Vde C, Souza RF, Silva CH, Paranhos Hde F. Antimicrobial action of sodium hypochlorite and castor oil solutions for denture cleaning-in vitro
evaluation. Braz Oral Res 2015;29:1-6.
Autoclave NG. Focus on infection control and dental laboratories. Br Dent J 2009;207:335-8.
Müller P, Tan CK, Ißleib U, Paßvogel L, Eilts B, Steinhauer K. Investigation of the susceptibility of Candida auris and Candida albicans to chemical disinfectants using European Standards EN 13624 and EN 16615. J Hosp Infect 2020;105:648-56.
Jennings KJ, Samaranayake LP. The persistence of microorganisms on impression materials following disinfection. Int J Prosthodont 1991;4:382-7.
Turhan Bal B, Yilmaz H, Aydin C, Al FD, Sultan N. Efficacy of various disinfecting agents on the reduction of bacteria from the surface of silicone and polyether impression materials. Eur J Prosthodont Restor Dent 2007;15:177-82.
Sukhija U, Rathee M, Kukreja N, Khindria S, Singh V, Palaskar J. Efficacy of Various Disinfectants on Dental Impression Materials. Int J Dent Sci 2009;9:1-6.
Schwindling FS, Rammelsberg P, Stober T. Effect of chemical disinfection on the surface roughness of hard denture base materials: A systematic literature review. Int J Prosthodont 2014;27:215-25.
da Silva FC, Kimpara ET, Mancini MN, Balducci I, Jorge AO, Koga-Ito CY. Effectiveness of six different disinfectants on removing five microbial species and effects on the topographic characteristics of acrylic resin. J Prosthodont 2008;17:627-33.
Ma T, Johnson GH, Gordon GE. Effects of chemical disinfectants on surface characteristics and color of three fixed prosthodontic crown materials. J Prosthet Dent 1999;82:600-7.
Ma T, Johnson GH, Gordon GE. Effects of chemical disinfectants on the surface characteristics and color of denture resins. J Prosthet Dent 1997;77:197-204.
Muscat Y, Farrugia C, Camilleri L, Arias-Moliz MT, Valdramidis V, Camilleri J. Investigation of acrylic resin disinfection using chemicals and ultrasound. J Prosthodont 2018;27:461-8.
Sartori EA, Schmidt CB, Walber LF, Shinkai RS. Effect of microwave disinfection on denture base adaptation and resin surface roughness. Braz Dent J 2006;17:195-200.
Dixon DL, Breeding LC, Faler TA. Microwave disinfection of denture base materials colonized with Candida albicans. J Prosthet Dent 1999;81:207-14.
Rueggeberg FA, Beall FE, Kelly MT, Schuster GS. Sodium hypochlorite disinfection of irreversible hydrocolloid impression material. J Prosthet Dent 1992;67:628-31.
[Figure 1], [Figure 2]
[Table 1], [Table 2]