Disinfection Of Impressions Research Articles

Tea Tree Oil Effect on Dimensional Change and Detail Reproduction of Addition Silicon Impression Material

Objective: Impression materials are thought to be the one of the primary sources of cross infection between patients and dentists. However, it was discovered that disinfection of the impression is not conducted routinely in ordinary dental treatment. Disinfection of addition silicon impression, whether by immersion or spray should not produce dimensional or detail errors. The purpose of this study was to examine the immersion of addition silicon impression material in tea tree oil and its influence on dimensional stability and detail reproduction of the addition silicon imprint material. Materials and Methods: This study employed a total of 120 heavy- and light-body addition silicon impression material specimens. The specimens were randomly sorted and immersed into six groups. These test groups where four concentrations of TTO (0.25%, 0.5%, 0.75%, and 1%), and the other two groups were distilled water (negative control) and 2% glutaraldehyde (positive control). All specimens were immersed for 10 minutes in the testing solutions. Each of the six groups had 20 specimens separated into two subgroups. Results: There were no statistically significant differences in linear dimensional changes and detail reproduction among all test groups. Conclusion: The addition silicon impression material may be safely submerged in TTO for 10 minutes to disinfect it without impairing its dimensional correctness or detail replication of the impression.

Antimicrobial Efficiency of Hypochlorous Acid Incorporation and its Effect on Surface Properties of Irreversible Hydrocolloid Materials

Objective: Conventional approaches for disinfection, including spraying and immersion, resulted in only surface disinfection of impressions. As a result, self-disinfecting impression materials incorporated with antimicrobial compounds require more extensive studies. The incorporation of a disinfectant into irreversible hydrocolloid impression materials could eliminate the need for the disinfection step by conventional approaches, including spraying and immersion which only result in surface disinfection of impressions. The study was aimed to investigate the effect of incorporation of hypochlorous acid in irreversible hydrocolloid materials on antimicrobial efficiency, detail reproduction, and dimensional stability. Materials and Methods: Hypochlorous acid (HOCl) was used in two concentrations, 100 ppm and 200 ppm, and mixed with alginate powder to compare with the control group (distilled water mixed with alginate). Candida albicans, Staphylococcus aureus, and Pseudomonas aeruginosawere chosen for assessing the antimicrobial activity with the disk diffusion test. In addition, the dimensional stability and reproduction of details were tested. Results: The results revealed that both HOCl concentrations of 100 ppm and 200 ppm imposed significant antimicrobial activity against all three tested microorganisms. There was no significant difference regarding reproduction of details, but the addition of the antimicrobial had a significant adverse effect on the alginate’s dimensional stability. Conclusion: It may be concluded that the incorporation of HOCL into irreversible hydrocolloid impression material resulted in an impression with antimicrobial activity. In addition, there was no effect on the impression materials ability to reproduce surface details, but the antimicrobial addition may affect its dimensional stability.

Evaluating Communication through Work Authorization between Dentists and Dental Technicians for Fixed Prosthesis

Communication within the dental profession can be challenging and may affect the quality of prostheses delivered to the patient. A methodical investigation into the dynamics between dentists and dental technicians is lacking in Lahore. Objective: To assess adequate practice of communication between dentists and dental technicians through work authorization for fixed prosthesis. Methods: This cross-sectional study was conducted in dental laboratories of Lahore. A questionnaire concerning work authorization forms was distributed to 80 dental technicians through Google Forms and hard copies. The survey concentrated on inquiries related to various aspects of work authorization, including gender, years of experience, impression disinfection, patient demographic data, impression materials used, fixed prosthesis design, and shade selection. An adequate work authorization was assessed in the end. Statistical analysis was conducted SPSS version 25.0 and was analyzed using chi-square, with significance set at p ≤ 0.05. Results: Out of the 80 survey forms disbursed, only 73 completely filled responses were accepted, giving a response rate of 91%. Information regarding patient demographic data (19.2%), patient photographic record (5.5%), pontic design (13.7%), margin design (37%), surfaces covered by metal (9.6%) and occlusal scheme (6.8%), were all on the inferior side of the scale ranging below 40%. Adequate practice of work authorization was discouraging, at only 17.8%. Conclusions: Poorly filled work authorization forms lead to patient and dentist dissatisfaction with fixed dental prostheses. This highlights the importance of clear communication between technicians and dentists. Dental students should learn to complete these forms during their training.

STUDY OF THE LEVEL OF KNOWLEDGE ABOUT HAND DISINFECTION AND THE APPLICATION OF ROUTINE DISINFECTION MEASURES AMONG DENTAL TECHNICIANS

Purpose: To study the level of knowledge about hand disinfection and the application of routine disinfection measures in everyday practice among dental technician students from the Medical College of Plovdiv and practicing dental technicians. Material and methods: For the period September 2019 - January 2020, an anonymous 19-question survey was conducted among a total of 92 dental technicians. All statistical analyses were performed with SPSS version 24. A p-value below 0.05 was considered statistically significant. Results: Of the respondents, 34.8% (n = 30) were students, and 65.2% (n = 62) were practicing dental technicians. The majority (77.2% (n = 71)) rate the hands as a factor for the transmission of microorganisms from person to person, but for 16.3% (n = 15), the hands pose a risk only if they are visibly contaminated. Only 31.5% (n = 29) disinfect their hands for the recomended 30 seconds. When working with dental impressions and dentures, 59.8% (n = 55) know that they must always be disinfected before working with them. The most commonly used preparations for disinfection of impressions are alcohols in 44.6% (n = 41), but 22.8% (n = 21) wrongly only use water and soap. Only 1/3 correctly state that the finished dentures should be disinfected before being handed to the dentist. Conclusion: Effective communication and coordination between the dental laboratory technicians and the dental office staff are critical components of a successful infection control program related to dental care

Impression Disinfection and Its Effect on Dimensional Accuracy and Surface Detail in the Times of COVID-19: An In Vitro Study.

Introduction The disinfection of impressions is crucial to eliminate the viral and other microbial loads to prevent the cross contamination of diseases. The aim of this study was to compare the effect of different virucidal disinfecting methods on the dimensional accuracy and surface detail reproduction (SDR) of impression materials. Methods A total of 160 samples were fabricated with different impression materials using zinc oxide eugenol (Group 1), alginate (Group 2), polyether (Group 3), and addition silicone (Group 4) impression materials, each containing 40 samples (n=40). These groups were further divided into Subgroups A, B, C, and D (n=10) based on the disinfecting method used. Disinfection was carried outusing 0.2% peracetic acid (A), a natural polymer of glucosamine (B), ultraviolet (UV) radiation (C), and ozonated water (D). The disinfected impressions were poured in type IV gypsum, and the obtained casts were checked for dimensional accuracy and surface detail reproduction (SDR). For dimensional accuracy, a one-way analysis of variance (ANOVA) test and, for surface detail reproduction, the chi-square test were used to compare the different subgroups of each impression material separately. Results Zinc oxide eugenol samples showed the lowest mean dimensional change when disinfected with 0.2% peracetic acid (1A=154.1 µm), and alginate showed the lowest mean dimensional change when disinfected using ozonated water (2D=134.9 µm). On the other hand, the lowest mean dimensional change observed in polyether and addition silicone samples was those which were disinfected using UV radiation (3C=100.9 µm and 4C=113.5 µm). Surface detail was reproduced adequately in most of the samples. Conclusion A 0.2% peracetic acid could be used to disinfect zinc oxide eugenol impressions, ozonated water for alginate impressions, and UV radiation for polyether and addition silicone impressions.

Knowledge, attitude, and practice of dental health professionals toward dental impression disinfection protocol during the COVID-19 pandemic in Saudi Arabia– a cross-sectional study

BackgroundDespite the updated guidelines on dental impression disinfection protocols during the COVID-19 pandemic, adherence to such procedures has not been studied among dental health professionals in Saudi Arabia. Understanding DHPs’ knowledge, attitudes, and practices regarding COVID-19 is crucial in assessing a willingness to adhere to the recommendations provided by health authorities in mitigating the spread of COVID-19 via dental impressions impacting patient safety and infection control measures. Hence, this study aimed to assess dental health professionals’ (DHPs) knowledge, attitudes, and practices (KAP) toward dental impression disinfection protocol during the COVID-19 pandemic in Saudi Arabia.MethodsA cross-sectional study using an online survey was conducted from 14 December 2022 to 21 March 2023 among practicing dentists, dental assistants (DA), dental laboratory technicians (DT), and dental hygienists in Saudi Arabia. A validated and reliable questionnaire that consisted of 38 items along with demographic variables was prepared to collect the data. Using Google Forms, a questionnaire link was prepared and shared on the social media platforms of DHPs in Saudi Arabia. A descriptive analysis was conducted to report the percentages and frequencies. The mean knowledge, attitude, and practice scores were analyzed using an Independent t-test, ANOVA, and Pearson’s correlation tests.ResultsA total of 718 DHPs voluntarily participated in the survey. Most of the DHPs exhibited average knowledge 392 (54.6%), neutral attitudes 393(54.7%), and adequate 549 (76.5%) practice towards dental impression disinfection protocol. The mean knowledge score differed significantly across nationality (p = 0.013), type of DHPs (p < 0.001), qualification (p = 0.045), and experience (p = 0.028) of the study participants. Significant differences in attitude towards impression disinfection were observed in different age groups (p = 0.002), qualifications (p = 0.015), and experiences (p = 0.024) of the DHPs. Similarly, practice varied across different age groups (p = 0.010), nationality (p = 0.013), type of DHPs (p = 0.019), qualification (p = 0.044), experience (p = 0.041), and COVID-19 Infection (p = 0.006). Moreover, a significant positive correlation between knowledge-attitude (r = 0.258, p < 0.01), knowledge-practice (r = 0.283, p < 0.01), and attitude-practice (r = 0.196, p < 0.01) was observed.ConclusionDHPs considered in this study demonstrated average knowledge and attitudes toward impression disinfection, requiring improvement through continuous dental education and training. However, they displayed acceptable dental impression disinfection practices during the COVID-19 pandemic. It is highly recommended that continuing education programs should mainly reinforce the knowledge of sodium hypochlorite, iodophor, and phenolics and their concentrations to be used as an impression disinfectant. Additionally, it should focus on techniques of disinfecting elastomeric, hydrocolloid, zinc oxide and eugenol, and impression compound materials to mitigate the spread of COVID-19 based on Saudi ministry of health guidelines.

Comparative Accuracy of Intraoral and Extraoral Digital Workflows for Short Span Implant Supported Fixed Partial Denture Fabrication: An In Vitro Study.

BACKGROUND The advent of digital impressions using computer-aided design and manufacturing technology (CAD/CAM) has simplified and improved the fabrication of implant prostheses in dentistry. The conventional impression has several drawbacks, including tray selection, material type, impression technique, impression disinfection, and cast model storage. The inaccuracies caused by distortion and contraction of impression material can be minimized with digital impressions. This study aimed to compare digital dental impressions of 10 working casts made using the Pindex laser removable die system to fabricate parallel drill channels vs 10 working casts made using the Di-Lok plastic tray removable die system. MATERIAL AND METHODS An implant master die with 2 dental implant analogs was fabricated. Ten working casts using the Pindex laser removable die system with parallel drill channels and 10 working casts using the Di-Lok plastic tray removable die system were fabricated. The working casts were scanned using an extra-oral laboratory scanner and the implant master model was scanned with an intra-oral scanner. RESULTS The properties of the casts made using the 2 systems were evaluated and analyzed with ANOVA and post hoc Tukey test. The mean horizontal linear distances between A1B1 (P<0.021), A2B2 (P<0.018), C1D1 (P<0.026), C2D2 (P<0.03), B1C1 (P<0.01), and mean vertical distances between B1A2 (P<0.015), C1D2 (P<0.001), B1B2 (P<0.028), and C1C2 (P<0.001) were significantly different between the Pindex system and Di-Lok tray system as compared to intra-oral scans. CONCLUSIONS Complete digital workflow with intra-oral scans were more than the partial digital workflow with extra-oral scans for the Pindex system and Di-Lok tray systems.

Efficacy of Ozone, UV Radiation, Herbal and Glutaraldehyde Method for Sterilisation of Elastomeric Impression Materials for Orthodontic and Prosthodontic procedures

ABSTRACT Objectives: The objectives of the current study was to evaluate the disinfection efficacy of ozone, ultraviolet (UV) radiation, herbal and glutaraldehyde method for sterilization of elastomeric impression materials Materials and Methods: Disinfection of elastomeric impression material was performed with each of the disinfection methods: ozone, UV radiation, herbal, and glutaraldehyde. Later microbiological analysis was performed and the colony-forming units were evaluated and compared. Results: The highest disinfection efficacy was found with glutaraldehyde, followed by ozone and UV radiation, and the least with neem herbal rinse. Intergroup comparison was highly significant Conclusion: Dry gaseous ozone and UV radiation can be used effectively for the disinfection of impressions.

Efficacy of an impression disinfectant solution after repeated use: An in vitro study

Statement of problemThere are very few studies using Benzalkonium Chloride (BAC) as an active disinfection agent for immersion techniques and there are no studies investigating the efficacy of repeated use of a disinfectant solution. PurposeThis study evaluated an impression disinfectant by testing bacterial contamination of disinfectant batches used in a clinical setting after repeated use. Materials and methodsLiquid samples were collected from impression disinfectant solutions used to disinfect dental impressions taken at a university dental clinic. The experimental samples (500 ml from 1 L of solution) were collected from teaching and professional clinics and the in-house commercial processing laboratory and stored at room temperature each day of clinic operation over five weeks. To determine to what extent the disinfectant efficacy of the active product decreased over time, the following tests were carried out: a. Inoculation b. Gram staining technique c. Matrix Assisted Laser Desorption/Ionization Mass spectrometry (MALDI- MS). Microbial growth was monitored and photographed. A culture revival was made from colonies grown on sheep blood agar, to isolate pure colonies incubated for 24 h at 37 °C. Each morphologically distinct type of colony was gram stained and MALDI spectrometry analysis was performed using the VITEK MS (BioMerieux Inc.) ResultsEvidence of growth of bacteria was detected in teaching clinics’ samples, and no growth from the professional clinic or the commercial laboratory. ConclusionsThe study demonstrated that the impression disinfectant solution tested is effective against common oral bacteria, despite some rare species such as Bacillus circulans, Bacillus horneckiae, Bacillus altitudinis/pumilus and Bacillus cereus showing evidence of survival in solutions used for disinfection of impressions. However, in a high use teaching clinic environment its efficacy deteriorated. Though a second level disinfection protocol in the commercial laboratory-maintained impression disinfection.

Knowledge about methods of disinfection of dental impression among dentists from Ecuador post SARS-COV-2 pandemic

PurposeThe aim of this study is to evaluate the understanding of the management of methods and practices of disinfection of dental impressions applied by general dentists and specialists in oral rehabilitation, post SARS-COV-2 pandemic. IntroductionThe oral cavity has a favorable environment for the growth and multiplication of bacteria and viruses, serving as the gateway to viruses such as SARS CoV-2 virus. Given that patients may be hosts of this infectious disease, stricter biosecurity measures in dental offices and a better understanding of the disinfection processes of dental impressions should be considered in addition to avoiding cross-infections, which are very common in our work environment. Materials and methodsDescriptive, analytical, survey with the topic "Methods and practices of disinfection of dental impressions" that was composed of 14 questions based in OHPD (Oral Health Preventive Dentistry), n = 452 respondents who met the following inclusion criteria: general practice dentists from Ecuador who actively take dental impressions, specialists in oral rehabilitation with 5 years of experience, surveys with information of complete items, n = 270 professionals; n = 192 general dentists, dental hygienist and n = 78 oral rehabilitation specialists. Resultsn = 270 professionals evaluated, with a mean of p = 0.0. At 426 responses with a p value of <0.05, 30.4 % of responses indicated ignorance in the management of dental impressions, with a standard deviation of 2.744, with significant differences between professions (p = 0.035) and higher average knowledge of sample management within specialist dentists, (Chi p = 0.410 p > 0.05) ConclusionThe understanding of the management of dental impressions among general dentists and specialists in oral rehabilitation is limited.

Comparison of the Bioactive and Bacteriostatic Performance of Different Alginate-Based Dental Prosthetic Impression Materials with and without Zirconium Phosphate-Based Ion Exchange Resin Containing Silver: An In Vitro Study

Disinfection of alginate impressions used in dental prosthetics is a very problematic procedure, during which the dimensions of the obtained model can change, and it can be easily mechanically damaged. Therefore, it would be beneficial to create a material with bacteriostatic properties for this application. In this work, we investigated alginate materials with the addition of 0.25–1.0 wt% of zirconium phosphate-based ion exchange resin containing silver and compared them with commercial alginate impression products. The obtained materials passed the normative requirements of ISO 21563:2021 (setting time, elastic recovery, strain in compression, compatibility with gypsum, detail reproduction, tearing strength, and linear dimensional change) as well as bacteriostatic properties in relation to Streptococcus mutans. The newly developed alginate materials met all the properties required by the standards. Their setting time was comparable to the commercial materials, and their 24 h contraction did not exceed 1.3%. Furthermore, the tearing strength was 0.42–0.48 MPa, less than that of the comparative commercial materials (0.52–0.56 MPa). From the point of view of clinical practice, it will be possible to create an alginate material with bacteriostatic properties that will prevent the transmission of cross-infections.

A Comparative Evaluation of Dimensional Change of Addition Reaction Elastomeric Impression Material After Disinfecting With 1% NaOCL and 3% H2O2: An in Vitro Study

Elastomeric impression materials are most commonly used impression materials in clinical practice for treating partially edentulous patient. After making impression it needs to be sterilized properly to minimize the risk of cross infection. Dimensional stability and accuracy of an impression after chemical disinfection by using different disinfectants are crucial for the accuracy of final prosthetic restoration. Until 1991 the recommended procedure for disinfection of impression was rinsing under running water with which only 40% of bacteria, virus, and fungi were removed and potential for transmission of microorganism remained there. Now a days most clinically used disinfection solutions are 3% hydrogen peroxide and 1% sodium hypochlorite. These two solutions are more effective to diminish microorganisms from the impression surface without altering dimensional stability.

Disinfection of polyvinyl siloxane impression material using ozone gas, 0.1% riboflavin, glutaraldehyde, and microwave irradiation and their effect on physical properties.

To assess the antimicrobial effect of ozone gas (OG) 0.1% riboflavin (RF), glutaraldehyde (GaH), and microwave irradiation (MI) on Polyvinyl siloxane impression material formerly colonized with E. coli, P. Aeruginosa, E. faecalis, and S.aureus and their effect on the physical properties MATERIAL AND METHODS: One hundred disk-shaped specimens (diameter 10mm and thickness 3mm) were developed by using polyvinylsiloxane impression material and inoculated by the American Type Culture Collection (ATCC) of E. coli, P. aeruginosa, E. faecalis, and S.aureus in an in-vitro setup. The samples were arbitrarily isolated into five groups and subjected for 3min to the designated disinfection modality. Group 1 Control, group 2: GaH, group 3: 0.1% RF, group 4: MI, and group 5 OG. Following decontamination, the physical properties (contact angle, strain-in-compression, and tear strength) of impression materials were evaluated. Statistical analysis for CFU/mL (log10) for exposed E. coli, P. aeruginosa, E. faecalis, and S.aureus was performed by using analysis of variance (ANOVA) and Tukey's multiple comparison tests at a p-value of less than 0.05. The most effective antimicrobial efficacy for impression disinfection against all scrutinized microbial colonies were displayed by group 5 OG and the lowest disinfection effectiveness was unveiled by the control group with no treatment. The intragroup comparison revealed that impression disinfection with GaH, MI, and ozone corroborated analogous antimicrobial efficacy(p>0.05). The disinfecting capacity of the impression material with 0.1% RF was significantly less than MI, GaH, and OG (p<0.05). Disinfection of polyvinyl siloxane impression material with ozone gas, microwave irradiation, and glutaraldehyde demonstrated reasonable antimicrobial efficiencies against E. coli, P. aeruginosa, E. faecalis, and S.aureus with no detrimental effects on the physical properties of impression material. More studies are advocated to extrapolate the findings of the present study.

The Efficacy of Three Types of Disinfectants on the Microbial Flora from the Surface of Impression Materials Used in Dentistry—In Vitro Study

During impressions, bacteria, viruses, and fungi remain on the impression material, representing a significant risk for the medical team (dentists, dental assistants, and laboratory technicians). Impression disinfectants have been introduced into dentistry to reduce the risk of cross-infection. This study was performed by examining the surface disinfection of five commonly used impression materials in prosthodontics: alginate-Tropicalgin (Zhermack®), condensation silicone-Zetaplus (Zhermack®), Oranwash L (Zhermack®); and addition silicone-Elite HD + Putty Soft (Zhermack®), Elite + Light Body (Zhermack®) after the disinfection with three disinfectants: Zeta 3 Soft (Zhermack®), Zeta 7 Spray (Zhermack®) and Zeta 7 Solution (Zhermack®). Before disinfection, the impression materials were contaminated with Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27853, and Candida albicans ATCC 10213. Our results demonstrate the efficacy of the two examined specific disinfectants in reducing cross-infection risk. The surface disinfectant-spray is not adequate for impression disinfection. A high number of bacterial colonies were found on the surface of all impressions disinfected with this spray. The immersion-disinfection method effectively eliminates the risk of cross-infections (Kruskal–Wallis test showed a p &lt; 0.001).

Pengaruh teknik desinfeksi dengan ekstrak daun salam (syzygium polyanthum w.) Terhadap stabilitas dimensi cetakan alginat (Laporan Penelitian)

Background: Alginate is the main impression material in dentistry and often linked to cross infection in dental practice. Disinfection of the alginate impression proven to be the key in controlling bacterial contamination but also impacting the dimensional stability of alginate impression. Bay leaf extract (Syzygium polyanthum w.) contains antibacterial compounds which can be used as disinfectant agent for alginate impression. Purpose: To analyze the dimensional stability of alginate impression after the disinfectant application with bay leaf extract by spraying and immersion techniques. Methode: The sample of this study is alginate impression made from the mold specification ANSI/ADA no. 18. There are 3 groups of samples, respectively 9 samples in each group. Group A serves as control, group B use spraying technique, and group C use immersion technique. Results were measured by digital caliper and statistically analyzed. Result: One Way Anova resulted in p-values &lt; 0.05, which means a significant difference in dimension after bay leaf extract disinfection procedures with spraying and immersion for 10 minutes. Conclusion: Disinfection technique with 25% bay leaf extract for 10 minutes have effect on alginate impression’s dimensional stability. The discrepancy is well below the ANSI/ADA no. 18 standard of &lt; 0.5% dimensional change. There is no significant difference in dimensional stability between different disinfectant technique.

Investigation of the Antimicrobial Effect of Different Disinfectants on Alginate Measurement Materials

Abstract Objective The impression materials are contaminated with pathogenic microorganisms carried by saliva and blood in the mouth. The aim of this study is to evaluate the antimicrobial activity of 1 and 5.25% sodium hypochlorite (NaClO) and zeta 7 solution, a commercial disinfectant, on alginate and to compare it washing with distilled water. Methods Samples obtained from alginate impressions taken from eight pediatric patients selected in accordance with the inclusion criteria with a size of 1 × 1 cm were subjected to five different disinfection protocols. After samples were vortexed in 3-mL physiological saline, 1-mL volume were inoculated onto brain heart infusion agar and cultured at 37°C for 72 hours to determine the number of colony-forming units/mL. Streptococcus mutans, Staphylococcus aureus, Escherichia coli, Candida albicans were used as control strains. The data obtained were statistically evaluated by using analysis of variance and post-hoc tests. The differences were considered statistically significant when p &lt; 0.05. Results All of the disinfectant solutions tested were effective in the disinfection of the impression materials examined. The control group with no treatment and the water and flushing group had a significantly higher bacterial load compared to the other disinfectant-treated groups in terms of bacterial load, and no significant difference has been observed between the disinfectant solutions (p &lt; 0.05). Simple rinsing of the impressions in sterile water reduced the number of microorganisms but did not decontaminate the impressions. Conclusion Washing with water alone is insufficient for measured disinfection. Although NaClO is an effective disinfectant even at low concentrations, microorganism growth was not observed at 5.25% concentration. It is appropriate to use NaClO at 1 and 5.25% concentrations for impression disinfection.

A Comparative Evaluation of the Effect of Ozonated Water and 2% Glutaraldehyde as disinfectants on the physical properties of polyvinyl siloxane impression material – An Invitro study

Aims: To compare the efficacy of ozone water and 2% glutaraldehyde in disinfecting polyvinyl siloxane impression and the effect of both disinfectants on the wettability, dimensional accuracy and surface detail reproduction of the material. Settings and Design: In vitro – comparative study Material and Methods: Samples (N =108) were subjected to disinfection either with 2% glutaraldehyde (group 1) or ozone water (group 2) for 15 minutes. To evaluate the efficacy, the samples were inoculated with Streptococcus mutans [ATCC 25175], Staphylococcus aureus [ATCC 25923] and Candida albicans [ATCC 10231]. Reductions in the number of microbial population after disinfection were determined by counting the colony forming units (CFU). The contact angle measurements on the impression surface were used to determine the wettability. Dimensional accuracy and surface detail reproductions of the samples were assessed with a stereomicroscope of 4X magnification. Statistical analysis used: paired t- test and chi-square test were used. Results: The efficacy of both disinfectants in reducing the microbial count found to be comparable. Both the disinfectants reduced the contact angle which improved the wettability of the material. Disinfection with 2% glutaraldehyde showed significant alteration in dimensional accuracy and surface detail reproduction (p&lt;0.05) when compared to samples disinfected with ozone water, which preserves the dimensional accuracy and surface details. Conclusions: Ozone water treatment was identified as a potential method for the disinfection of polyvinyl siloxane impression as it increased the wettability of the material, showed least dimensional changes and preserved surface details more accurately.

A Review on Risk Management of Coronavirus Disease 19 (COVID-19) Infection in Dental Practice: Focus on Prosthodontics and All-Ceramic Materials

Background: A novel β-coronavirus infection (COVID-19) was first detected in Wuhan city, spreading rapidly to other countries and leading to a pandemic. Dental professionals and patients are exposed to a high risk of COVID-19 infection, particularly in the prosthodontic practice, because of the bio-aerosol produced during teeth preparation with dental handpieces and the strict contact with oral fluids during impression making. This paper aimed to provide an overview to limit the risk of transmission of COVID-19 infections during prosthetic procedures in dental offices. Methods: An electronic search was conducted on the electronic databases of PubMed/Medline, Google Scholar, Embase, Scopus, Dynamed, and Open Grey with the following queries: (COVID-19) AND/OR (SARS-CoV-2) AND/OR (Coronavirus) AND/OR (contaminated surface) AND/OR (cross-infection) AND/OR (Prosthodontics) AND/OR (dental ceramic) AND/OR (glass-ceramic). A manual search was performed as well. Results: From the 1023 collected records, 32 papers were included. Conclusions: Dental offices are at high risk of spreading SARS-CoV-2 infection due to the close contact with patients and continuous exposure to saliva during dental procedures. Therefore, pre-check triages via telephone, decontamination, the disinfection of impressions, the sterilization of scanner tips, and the use of specific personal protective equipment, dental high-speed handpieces with dedicated anti-retraction valves, and effective mouthwashes are strongly recommended.

Effect of alginate impression disinfection with sodium hypochlorite and castrol oil on Candida albicans counts and dimensional stability of the study model

Alginate is the most common used material because it is easy to use, affordable, and well accepted by patients. When impressing, alginate would be in contact with the surface of the oral cavity and saliva. It caused the microflora, like Candida albicanswould adhere to the surface so that it can cause cross-infection. Cross-infection prevention could be done by disinfecting the impression material before filling with gypsum. The main things of choosing a disinfectant is that the disinfectant material could eliminate microorganisms and affect the dimensional stability of impression material. This study aimed to determine the effect of alginate impression disinfection with sodium hypochlorite and castor oil (Ricinus communis oil) on the Candida albicanscounts and the dimensional stability of the study model. The samples of Candida albicanswas counted by colony counter andthe dimensional stability test by digital caliper. This study showed that alginate impression desinfection with castor oil had almost the same effectiveness as sodium hypochlorite in reducing the Candida albicanscounts, but dimension was changed even though the value of the dimensional changes is still within the tolerance limit.

Evaluation of Antimicrobial Efficacy of UVC Radiation, Gaseous Ozone, and Liquid Chemicals Used for Disinfection of Silicone Dental Impression Materials.

Effective disinfection of dental impressions is an indispensable requirement for the safety of dental personnel and patients. The ideal method should be not only effective but also convenient, cheap, and environmentally friendly. This study aimed to reliably evaluate the efficacy of ultraviolet C (UVC) radiation, gaseous ozone, and commercial liquid chemicals used for silicone dental impressions disinfection. These methods were applied to two types of elastomeric impression materials: condensation silicones and addition silicones of various consistency (putty, medium, and light). The antimicrobial effectiveness against Pseudomonas aeruginosa, Staphylococcus aureus, and Candida albicans was evaluated in vitro by counting colony-forming units (CFU) on the surface of samples. The one-way ANOVA with a Tukey HSD test or the Kruskal–Wallis with a Dunn’s test was performed. The results obtained revealed the efficacy of the proposed methods for disinfection of both C-silicones and A-silicones in most of the studied groups. Only one material (Panasil initial contact Light) was not effectively disinfected after UVC irradiation or ozone application. In conclusion, the potential of each disinfection method should be evaluated separately for each material. Moreover, in further research, the possible influence of the proposed methods on the physical properties of the impression materials should be thoroughly investigated.