Comparison of the efficacy of disinfectants for cleaning complete removable acrylic dentures

Svetlana N. Razumova; Разумова Светлана Николаевна; Anzhela S. Brago; Браго Анжела Станиславовна; Dmitry V. Serebrov; Серебров Дмитрий Витальевич; Malina D. Baikulova; Байкулова Малина Джандауровна; Elena A. Morozova; Морозова Елена Анатольевна; Kirill D. Serebrov; Серебров Кирилл Дмитриевич

doi:10.17816/dent632622

Comparison of the efficacy of disinfectants for cleaning complete removable acrylic dentures

Authors: Razumova S.N.¹, Brago A.S.¹, Serebrov D.V.¹, Baikulova M.D.¹, Morozova E.A.¹, Serebrov K.D.¹
Affiliations:
1. Peoples’ Friendship University of Russia
Issue: Vol 29, No 1 (2025)
Pages: 63-72
Section: Clinical Investigations
Submitted: 28.05.2024
Accepted: 15.10.2024
Published: 01.03.2025
URL: https://rjdentistry.com/1728-2802/article/view/632622
DOI: https://doi.org/10.17816/dent632622
ID: 632622

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Abstract
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Abstract

BACKGROUND: The problem of effective cleaning and disinfection of removable dental prostheses remains relevant, as currently available methods do not always yield satisfactory results.

AIM: To compare the effectiveness of the "Anolit ANK Super" solution (Dolphin Aqua, Russia) and a 0.05% chlorhexidine bigluconate solution for disinfecting partial and complete removable dentures.

MATERIALS AND METHODS: The study assessed the disinfectant properties of “Anolit ANK Super” solution in comparison with a 0.05% chlorhexidine solution. A total of 60 patients with complete removable acrylic dentures were examined. The effectiveness of denture cleaning was evaluated using mass spectrometry on a Maestro-αMS gas chromatograph-mass spectrometer (Interlab, Russia).

Statistical analysis was performed using Statistica 13 software. Parametric tests, including the Student’s t-test with Bonferroni correction for multiple comparisons, were used to assess differences between groups. A p-value of 0.05 was considered the threshold for statistical significance.

RESULTS: The study demonstrated that after immersion in “Anolit ANK Super” solution, the number of fungi and yeasts decreased from (1846.0 ± 81.0) to (125.0 ± 33.0) 10⁵ CFU/g (p = 0.03). The number of anaerobic bacteria decreased from (154.0 ± 9.0) to (10 ± 3.0) 10⁵ CFU/g (p = 0.006). The number of actinobacteria decreased from (163.0 ± 30.0) to (8.0 ± 4.0) 10⁵ CFU/g (p = 0.03). After exposure to Anolit ANK Super, the number of cocci and bacilli decreased from (135.0 ± 11.0) to (3.0 ± 3.0) 10⁵ CFU/g (p = 0.009).

CONCLUSION: The Anolit ANK Super solution is effective against fungi and yeasts, anaerobic microorganisms, actinobacteria, cocci, and bacilli present on denture surfaces. The reduction in microbial load is proportional to the duration of denture immersion in the solution (p = 0.0001).

Keywords

removable dentures, oral microbiota in patients with removable dentures, denture hygiene, methods of hygienic denture cleaning, anolyte

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BACKGROUND

The problem of effective cleaning and disinfection of removable dentures remains relevant, as the World Health Organization has reported a steady increase in the global elderly population [1, 2]. A substantial proportion of patients with removable dentures are older adults who often experience difficulties in maintaining proper denture hygiene [3]. According to Razumova et al. [4] and Tabet et al. [5], up to 76% of cases showed unsatisfactory oral and denture hygiene. Maintaining adequate oral hygiene is the primary preventive measure against various dental diseases. The oral microbiota is a complex ecological system that can be altered by multiple factors, including humidity, changes in pH and temperature, presence of prostheses, and oral hygiene practices [6]. Microbial plaque consists of structured microbial communities embedded in a polysaccharide matrix and is found not only on oral tissues but also on restorative and prosthetic materials, including dentures [6, 7].

Acrylic dentures are the most commonly used type of removable dental prosthesis. Acrylic resin is a rigid and porous material, and micropores on the surface of acrylic denture bases serve as retention sites for microorganisms. Microbial colonization of denture surfaces leads to plaque accumulation, negatively affecting oral hygiene. Residual monomers, pigments, and other components of acrylic resin may trigger allergic reactions and, when combined with microbial factors, can contribute to toxic-allergic reactions [8].

Murakami et al. identified more than 60 species of prokaryotes from denture plaque. The predominant microorganisms included Candida spp. (particularly Candida albicans, Candida glabrata, and Candida tropicalis), Streptococcus mutans, Streptococcus salivarius, Streptococcus mitis, lactobacilli, corynebacteria, Haemophilus, and Streptococcus pneumoniae [9].

Studies by Rubtsova et al. demonstrated that inadequate hygienic maintenance of removable dentures allows pathogenic microorganisms to penetrate up to 2.0–2.5 mm into the polymer bases of prostheses [10]. Over time, microcracks develop on denture surfaces, creating additional sites for microbial adhesion. Poor oral and denture hygiene promotes plaque accumulation, worsening the patient’s oral hygiene status and increasing the risk of oral diseases [11, 12].

There is a direct correlation between oral hygiene and systemic health. The presence of microbial biofilm on denture surfaces has been linked to systemic conditions such as bacterial endocarditis, aspiration pneumonia, and chronic obstructive pulmonary disease [13].

Currently available methods of denture cleaning and disinfection do not always provide satisfactory results, as not all disinfectants are equally active against microorganisms colonizing denture surfaces. Therefore, disinfecting agents should be selected not only for their ability to clean dentures effectively but also to prevent recolonization.

A review of the publications on denture disinfection methods revealed four main approaches: mechanical cleaning (with toothbrush and paste), chemical disinfection, device-assisted methods, and application of protective coatings. Chemical disinfection is the most widely used. According to Razumova et al., 0.05% chlorhexidine solution is among the most common agents for denture disinfection [14]. Anolit ANK Super (Delfin Aqua, Russia) has been widely applied in medicine and the food industry for disinfection of surfaces, equipment, instruments, slaughterhouses, containers, wastewater, clothing, vehicles, and other objects [15]. However, no studies have been found on its use for denture disinfection, which underscores the novelty and relevance of assessing Anolit ANK Super for disinfecting partial and complete removable dentures compared with 0.05% chlorhexidine solution.

This work aimed to compare the efficacy of Anolit ANK Super solution and 0.05% chlorhexidine digluconate solution for disinfecting partial and complete removable dentures.

METHODS

Study Design

It was an observational, single-center, prospective, randomized, controlled, blinded study.

Eligibility Criteria

Inclusion criteria were age between 50 and 80 years, use of complete removable acrylic dentures, and absence of allergic reactions.

Study Setting

The study was conducted at the Department of Propaedeutics of Dental Diseases, Patrice Lumumba Peoples’ Friendship University of Russia (RUDN University), Clinical and Diagnostic Center.

Study Duration

The study was conducted from November 2023 to May 2024.

Intervention

The quantitative and qualitative composition of the oral microbiota was determined using mass spectrometry of microbial markers. Swabs were collected from the internal surfaces of complete removable acrylic dentures of both jaws before any hygienic cleaning. Samples were placed in labeled tubes, transported in a refrigerated container to the laboratory, sorted, and inspected for integrity. Until analysis, samples were stored in a specialized thermostat to maintain optimal conditions and preserve bacterial viability. The samples were then analyzed using the Maestro-αMS gas chromatography–mass spectrometer (Interlab, Russia).

Main Study Outcome

Increasing the duration of denture immersion in the disinfectant solutions reduced both the quantitative and qualitative indicators of microbial colonization on denture surfaces.

Additional Study Outcomes

Reduction in microbial counts on denture surfaces improved denture hygiene status.

Subgroup Analysis

Participants were randomly assigned into two groups. In Group 1 (intervention group, n = 30), dentures were treated with Anolit ANK Super solution. In Group 2 (control group, n = 30), dentures were treated with 0.05% chlorhexidine digluconate solution.

Outcomes Registration

To register the primary and secondary outcomes, swabs were taken from denture surfaces. The collected samples were analyzed using mass spectrometry.

Ethics Approval

According to protocol No. 18 dated May 18, 2023, the Ethics Committee of the Medical Institute of Patrice Lumumba Peoples’ Friendship University of Russia (RUDN University) approved the study “Comparison of the Efficacy of Disinfectants for Cleaning Complete Removable Acrylic Dentures.” All participants provided written informed consent prior to inclusion in the study.

Statistical Analysis

Statistical analysis was performed using Statistica, version 13 (StatSoft Inc., USA). The data distribution was consistent with normality; therefore, descriptive statistics included calculation of means and standard deviations. Parametric tests, including Student’s t-test with Bonferroni correction for multiple comparisons, were applied to assess intergroup differences. A p-value of 0.05 was considered the threshold for statistical significance.

RESULTS

Participants

Microbial contamination of complete removable acrylic dentures was assessed. In Group 1, dentures were immersed in Anolit ANK Super solution for 5 minutes, 20 minutes, and 8 hours. In Group 2, dentures were immersed in 0.05% chlorhexidine digluconate solution for the same time intervals.

Primary Results

The results demonstrated that both 0.05% chlorhexidine and Anolit ANK Super reduced microbial counts on denture surfaces.

Before disinfection, denture surfaces harbored 1846.0 ± 81.0 × 10⁵ cells/g of fungi and yeasts. After 5-minute immersion in 0.05% chlorhexidine and Anolit ANK Super, this decreased to 1608.0 ± 65.0 × 10⁵ cells/g (p = 0.00) and to 312.0 ± 24.0 × 10⁵ cells/g (p = 0.003), respectively. After 20-minutes immersion, the fungal and yeast counts decreased to 967.0 ± 27.0 × 10⁵ cells/g with 0.05% chlorhexidine (p = 0.00) and to 215.0 ± 35.0 × 10⁵ cells/g with Anolit ANK Super (p = 0.04). After 8 hours, fungal and yeast counts were reduced to 825.0 ± 126.0 × 10⁵ cells/g with 0.05% chlorhexidine (p = 0.00) and to 125.0 ± 33.0 × 10⁵ cells/g with Anolit ANK Super (p = 0.03). These data are presented in Fig. 1.

Fig. 1. Fungal and yeast counts on denture surfaces before and after disinfection.

Before disinfection, denture surfaces contained 154.0 ± 9.0 × 10⁵ cells/g of anaerobic microorganisms. After 5-minute immersion in 0.05% chlorhexidine and Anolit ANK Super, the count decreased to 101.0 ± 9.0 × 10⁵ cells/g (p = 0.00 and to 15.0 ± 1.0 × 10⁵ cells/g (p = 0.005), respectively. After 20 minutes, anaerobic counts decreased to 90.0 ± 5.0 × 10⁵ cells/g with 0.05% chlorhexidine (p = 0.00) and to 12.0 ± 3.0 × 10⁵ cells/g with Anolit ANK Super (p = 0.004). After 8 hours, anaerobic counts reduced to 58.0 ± 4.0 × 10⁵ cells/g with 0.05% chlorhexidine (p = 0.00) and to 10.0 ± 3.0 × 10⁵ cells/g with Anolit ANK Super (p = 0.006). These data are presented in Fig. 2.

Fig. 2. Anaerobic microorganism counts on denture surfaces before and after disinfection.

Before disinfection, denture surfaces harbored 163.0 ± 30.0 × 10⁵ cells/g of actinobacteria. After 5 minutes of immersion in 0.05% chlorhexidine, the number decreased to 143.0 ± 7.0 × 10⁵ cells/g (p = 0.00), whereas immersion in Anolit ANK Super reduced the count to 16.0 ± 4.0 × 10⁵ cells/g (p = 0.00002). After 20 minutes, actinobacteria counts decreased to 102.0 ± 5.0 × 10⁵ cells/g with 0.05% chlorhexidine (p = 0.00) and to 12.0 ± 3.0 × 10⁵ cells/g with Anolit ANK Super (p = 0.006). After 8 hours, actinobacteria counts declined to 30.0 ± 2.0 × 10⁵ cells/g with 0.05% chlorhexidine (p = 0.00) and to 8.0 ± 3.0 × 10⁵ cells/g with Anolit ANK Super (p = 0.03). These data are presented in Fig. 3.

Fig. 3. Actinobacteria counts on denture surfaces before and after disinfection.

Before disinfection, denture surfaces contained 135.0 ± 11.0 × 10⁵ cells/g of cocci and bacilli. After 5 minutes of immersion in 0.05% chlorhexidine, this decreased to 107.0 ± 8.0 × 10⁵ cells/g (p = 0.00), and after immersion in Anolit ANK Super to 15.0 ± 5.0 × 10⁵ cells/g (p = 0.03). After 20 minutes, cocci and bacilli decreased to 56.0 ± 4.0 × 10⁵ cells/g with chlorhexidine (p = 0.00) and to 8.0 ± 3.0 × 10⁵ cells/g with Anolit ANK Super (p = 0.007). After 8 hours, counts were further reduced to 12.0 ± 2.0 × 10⁵ cells/g with 0.05% chlorhexidine (p = 0.00) and to 3.0 ± 3.0 × 10⁵ cells/g with Anolit ANK Super (p = 0.009). These data are presented in Fig. 4.

Fig. 4. Cocci and bacilli counts on denture surfaces before and after disinfection.

The study established a direct correlation between immersion time and disinfectant efficacy in both groups. Eight hours of immersion were significantly more effective than 20 minutes (p = 0.003), and 20 minutes were more effective than 5 minutes (p = 0.002). The optimal disinfection protocol was an 8-hour immersion in Anolit ANK Super, which demonstrated the highest cleaning and disinfecting efficacy (p = 0.0001).

Secondary Results

Because microbial counts decreased with longer denture immersion times, it can be concluded that the use of Anolit ANK Super solution for denture disinfection improves denture hygiene status.

Adverse Events

No adverse events were reported.

DISCUSSION

Mass spectrometric analysis of microbial markers revealed that the levels of Bacillus megaterium, Staphylococcus epidermidis, Clostridium difficile, Prevotella spp., Corynebacterium spp., Bifidobacterium spp., cytomegalovirus, Nocardia asteroides, Propionibacterium freudenreichii, Eubacterium spp., Streptomyces spp., and fungal metabolites (campesterol) were more than twice the permissible norm on denture surfaces, worsening oral hygiene. Mass spectrometry and subsequent data analysis confirmed that Anolit ANK Super was effective against fungi, yeasts, anaerobic microorganisms, actinobacteria, bacilli, and cocci. Immersion in 0.05% chlorhexidine decreased fungal and yeast counts by 1.4-fold after 5 minutes, 2.0-fold after 20 minutes, and 2.2-fold after 8 hours. In comparison, immersion in Anolit ANK Super reduced fungal and yeast counts by 6.0-fold after 5 minutes, 8.6-fold after 20 minutes, and 14.7-fold after 8 hours. Anolit ANK Super demonstrated significantly greater efficacy against fungi and yeasts compared with 0.05% chlorhexidine (p = 0.000000).

Fig. 5. Removable dentures before disinfection.

Fig. 6. Removable dentures after 5 minutes of disinfection.

Fig. 7. Removable dentures after 20 minutes of disinfection.

Fig. 8. Removable dentures after 8 hours of disinfection.

For anaerobic microorganisms, 0.05% chlorhexidine reduced counts 1.5-fold after 5 minutes, 1.7-fold after 20 minutes, and 2.6-fold after 8 hours. In contrast, Anolit ANK Super reduced anaerobic counts 10-fold after 5 minutes, 12.8-fold after 20 minutes, and 15.4-fold after 8 hours. Anolit ANK Super was significantly more effective against anaerobes than 0.05% chlorhexidine (p = 0.000000).

For actinobacteria, 0.05% chlorhexidine decreased bacterial counts 1.1-fold after 5 minutes, 1.5-fold after 20 minutes, and 5.4-fold after 8 hours. Anolit ANK Super reduced actinobacteria 10-fold after 5 minutes, 13-fold after 20 minutes, and 20-fold after 8 hours. Anolit ANK Super was significantly more effective against actinobacteria than 0.05% chlorhexidine (p = 0.000000).

For cocci and bacilli, immersion in 0.05% chlorhexidine reduced counts 1.3-fold after 5 minutes, 2.4-fold after 20 minutes, and 11.2-fold after 8 hours. In comparison, immersion in Anolit ANK Super reduced counts 9.0-fold after 5 minutes, 16.8-fold after 20 minutes, and 45.0-fold after 8 hours. Anolit ANK Super demonstrated significantly greater efficacy against cocci and bacilli than 0.05% chlorhexidine (p = 0.000000).

Kalivradzhiyan et al. compared the effectiveness of a new disinfectant composition (cetrimide, silver ions, and chitosan succinate) with 0.05% chlorhexidine digluconate for denture disinfection. Their results showed that chlorhexidine was active against Staphylococcus aureus, Streptococcus mutans, Streptococcus sanguis, Candida albicans, Candida tropicalis, and Escherichia coli. However, the qualitative composition of the oral microbiota remained unchanged, with only quantitative reduction observed—findings consistent with our data. By contrast, Anolit ANK Super provided more effective denture cleansing and disinfection due to its broader antimicrobial spectrum [16].

Ruiz Núñez et al. evaluated the efficacy of 0.05% chlorhexidine digluconate and concluded that oral and denture disinfection with this agent did not achieve effective cleansing. The authors noted that its bacteriostatic effect predominates over bactericidal action [17]. Our study confirmed the effectiveness of chlorhexidine with prolonged immersion. In contrast, the Anolit ANK Super solution was more effective than chlorhexidine in eliminating pathogenic microorganisms from the surface of dentures.

Ribeiro Rocha et al. conducted a review on denture disinfection methods and concluded that alkaline peroxides are not active against Candida spp., whereas 0.05% chlorhexidine and chlorine dioxide significantly reduce colony-forming units. Nevertheless, in our study, Anolit ANK Super immersion for 5 minutes, 20 minutes, and 8 hours was consistently more effective than chlorhexidine at equivalent immersion times [18].

CONCLUSION

Anolit ANK Super solution demonstrated efficacy against fungi and yeasts, anaerobic microorganisms, actinobacteria, cocci, and bacilli on denture surfaces. Microbial reduction was proportional to immersion time (p = 0.0001). The most effective disinfection protocol was an 8-hour immersion in Anolit ANK Super solution.

ADDITIONAL INFORMATION

Funding sources: The authors declare no external funding was received for the study or article.

Disclosure of interests: The authors have no relationships, activities, or interests (personal, professional, or financial) with third parties (for-profit, not-for-profit, or private entities) whose interests may be affected by the content of this article. The authors also report no other relevant relationships, activities, or interests within the past three years.

Author contributions: S.N. Razumova: writing—review & editing; A.S. Brago: investigation; D.V. Serebrov: formal analysis; E.A. Morozova: writing—original draft; M.D. Baykulova: investigation; K.D. Serebrov: writing—review & editing. All authors approved the version of the manuscript to be published and agreed to be accountable for all aspects of the work, ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.