RiteeshGrandhi/sciclaimeval-shared-task huggingface dataset:
Results
Figure 1 and Table 1 present the physical properties of alginate impression materials mixed with a 10 mg/mL, 15 mg/mL, or 20 mg/mL CA solution. The concentration of CA solution used in the mixing process significantly impacted the deformation elastic recovery and strain-in-compression of the alginate dental impression material ( P < 0.01). However, all measurements fell within the standard range of ISO 21563 ( Standardization, 2021 ) for alginate impression materials. The initial setting time of alginate impressions mixed with different CA solution concentrations also differed significantly ( P < 0.01). Only the impressions mixed with 10 mg/mL CA solution fell within the initial setting time range of 1–5 min specified by the T-6505 Japanese Industrial Standard ( Kitamura & Kawai, 2015 ). The fluidity of the oral model was affected by the various CA solution concentrations ( P < 0.01), but all three materials complied with the ANSI/ADA Specification No. 18-1992 ( Dental Materials, 1992 ) regarding the fluidity of alginate impression materials.

Figure 2 illustrates the changes in viable microorganism populations on impressions during CA intervention for up to 30 min. Values are presented as means ± SD ( n = 5). Analysis of the repeated measurements indicated that different intervention methods had varying disinfection effects on the four types of bacteria ( P < 0.01), with the number of viable bacteria decreasing as the intervention time increased. After 30 min, only those receiving disinfection through mixing a CA solution with the impression material (10 mg/mL) or through spray disinfection with only a CA solution (60 mg/mL) had high colony counts for Staphylococcus aureus , Escherichia coli , Candida albicans , and Streptococcus pneumoniae . However, when self-disinfection with a CA solution was combined with spray disinfection, there was a significant reduction in colony count for all four bacteria ( P < 0.01).

The dimensional accuracy test results for three different oral impression methods are displayed in Figure 3 . These methods include pure distilled water mixing, disinfection with 2,000 mg/L available chlorine after distilled water mixing, and spray disinfection with 60 mg/mL CA solution after mixing with a 10mg/mL CA solution. When comparing these three alginate dental impression processing methods, there was no statistically significant difference in the impact of available chlorine spray disinfection and CA solution treatment on the dimensional accuracy of dental impressions ( P > 0.05).
Limitations
This study also had limitations that should be considered. This study did not apply the CA disinfection protocol to impressions taken from the oral cavity, which will occur in future studies. Secondly, due to the antioxidant properties of CA, the alginate impression turns from the original blue to yellow after adding CA, which may affect the mood of the patient when making the impression. In addition, CA is recognized as an important antioxidant with broad-spectrum antiviral activities against HSV-1 and HSV-2 ( Adeosun et al., 2022 ), HIV ( Fredsgaard et al., 2023 ), and adenovirus ( Ma et al., 2017 ). However, this particular study does not investigate the antiviral activity of CA on dental impressions.
Conclusions
This study is the first to investigate the effect of CA disinfection on alginate impressions. The results demonstrate that four physical properties of alginate impression materials mixed with a CA solution of 10 mg/mL met industry standards. Additionally, alginate impression materials mixed with CA solutions of 10 mg/mL, 15 mg/mL, and 20 mg/mL were found to be within the acceptable range for elastic recovery, strain-in-compression, and fluidity.

The CA disinfection protocol exhibited a significant inhibitory effect on the four selected oral pathogenic bacteria, particularly Staphylococcus aureus . Importantly, the dimensional accuracy of alginate impressions was not affected by CA mixing and spraying disinfection. CA is natural and non-irritating, with broad-spectrum antimicrobial properties. It is environmentally friendly, does not cause bacterial resistance, and has no negative impact on the health of medical personnel. Therefore, using CA as an alginate mold disinfectant is highly feasible. This study also indicates that CA is a promising traditional Chinese medicine impression disinfectant. These findings offer an experimental foundation for the clinical application of CA in dental impressions. In the future, more clinical trials will be conducted to explore the potential of CA as a clinical alternative to alginate impression disinfectants. This study also promotes further application of CA in stomatology.
Supplemental Information
Antibacterial effect of chlorogenic acid solution intervention on alginate impression materials
Figure 1: Effect of alginate impression material mixed with three chlorogenic acid liquids of different concentrations on its physical properties.
(A) The elastic recovery of alginate impression material changes with the concentration of chlorogenic acid. (B) The strain-in-compression of alginate impression material increases with the increase of chlorogenic acid concentration. (C) The initial setting time of alginate impression material becomes longer with the increase of chlorogenic acid concentration. (D) The mobility of alginate impression material is enhanced with the increase of chlorogenic acid concentration.

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DOI: 10.7717/peerj.18228/fig-1
Figure 2: Antimicrobial effect of chlorogenic acid solution intervention on alginate impression materials.
(A) Staphylococcus aureus (B) Escherichia coli (C) Candida albicans (D) Streptococcus pneumoniae. The error bar represents the standard deviation; Dashed lines indicate detection limits.

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DOI: 10.7717/peerj.18228/fig-2
Figure 3: Effect of chlorogenic acid intervention on the precision of gypsum injection of alginate impression material.
The deviation between the plaster model and the standard model of different intervention methods is used as the parameter of root mean square (RMS) after fitting overlap. (BC, Blank control: The impression was prepared by mixing distilled water without any other treatment. CL, Available chlorine intervention group: The impression was prepared by mixing distilled water, 2,000 mg/L available chlorine spray disinfection. CA, Chlorogenic acid intervention group: The impression was prepared by mixing 10 mg/L chlorogenic acid, 60 mg/L chlorogenic acid spray disinfection).

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DOI: 10.7717/peerj.18228/fig-3
Comparison of physical properties of alginate impression materials after mixing with different concentrations of chlorogenic acid.