Assessing the effect of Artemisia sieberi extracts on surface roughness and candida growth of digitally processed denture acrylic materials

Abstract

BACKGROUND:

Denture stomatitis, frequently encountered, is generally addressed symptomatically, with limited exploration of preventive approaches involving antifungal medicinal plants.

OBJECTIVE:

This study assessed the impact of Artemisia sieberi extracts on the candida growth of conventional and digitally processed acrylic materials.

METHOD:

Thirty acrylic resin discs (3 mm thickness $\times$ 10 mm diameter) were prepared by conventional or CAD/CAM technology (milling and 3D printing). The resin discs were exposed to simulated brushing, thermocycling, and immersion in Artemisia sieberi extract for 8 hours. The surface roughness of the discs was assessed at baseline and after immersion in Artemisia sieberi extract. Candida growth was quantified through colony-forming units (CFU/mL). Data was analyzed using SPSS v.22 ( $\alpha\leqslant$ 0.05).

RESULTS:

Irrespective of the material type, the post-immersion surface roughness was significantly higher compared to pre-immersion values ( $p<$ 0.05). Candida growth was significantly higher in conventional acrylic materials than digitally fabricated acrylics ( $p<$ 0.05). At $\times$ 3, Ra and CFU were found to be moderately positive and non-significantly correlated ( $R=$ 0.664, $p=$ 0.149). At $\times$ 4, Ra and CFU were found to be weak positive and non-significantly correlated ( $R=$ 0.344, $p=$ 0.503).

CONCLUSION:

Artemisia sieberi extracts had a notable impact on digitally fabricated denture acrylics, reducing candida albicans growth compared to conventional heat-cured acrylic. This suggests a potential role for these extracts in improving denture hygiene and preventing denture stomatitis, particularly in the context of digitally fabricated dentures.

Keywords

3D printing candida growth roughness colony forming units

1. Introduction

Edentulism impacts individuals and communities, causing functional and social limitations. In unrestored edentulism, eating and social interactions may be impacted significantly [1]. Furthermore, tooth loss negatively impacts one’s quality of life due to poor esthetics, mastication, and speech problems [2]. Numerous socioeconomic factors contribute to edentulism, including poverty, poor education, and a lack of social support, especially for the elderly [3].

In dental practice, polymethyl methacrylate (PMMA) acrylic-based resins are frequently used to construct removable complete dental prostheses. They offer properties and characteristics that enable them to be utilized in multiple applications [1, 4, 5]. Polymethyl methacrylate materials offer advantages that include low density, aesthetics, efficiency, low cost, reparability, and minimal weight. It is also important to note that PMMA has some drawbacks, including susceptibility to water absorption, low flexural strength, dimensionally unstable, residual monomers, and potential to surface voids, which might compromise the mechanical properties and esthetics [6, 7, 8, 9]. In recent years, complete dentures have been fabricated using computer-assisted design/computer-assisted manufacturing (CAD/CAM) technology. The CAD/CAM technology-assisted dentures (milling and 3D-printing) overcome the drawbacks of conventional dentures [1]. However, CAD/CAM technology has several disadvantages, including high costs and complex intraoral assessment of trial dentures by clinicians and patients [9, 10, 11].

A denture prosthesis must meet the patient’s physical, mechanical, and aesthetic needs. However, dentures and oral lesions, such as ulcers, mucogingival hyperplasias, and oral candidiasis, are often associated [1, 12]. A denture’s tissue surface often exhibits pitting and microporosities, which makes it challenging to remove microorganisms from these areas mechanically or chemically [13]. Surface roughness significantly influences bacterial retention. The prosthesis may serve as an infection reservoir, and roughness increases the possibility of microorganisms adhering to the surface even after cleaning. All these factors lead to denture stomatitis [5, 14].

Denture stomatitis is the mucosa inflammation underlying a complete denture caused by microbial factors, especially candida albicans [15]. Murat et al. [16] reported that PMMA-based CAD/CAM polymers showed lower candida adhesion than heat-polymerized PMMA. The standard management of denture stomatitis involves a variety of treatment options, including denture disinfectants, denture cleansers, and systemic antifungal medications. However, their uses are limited today due to their toxic side effects [15]. Accordingly, medicinal plants that have proven antibacterial and antifungal, especially against candida species, have been introduced to dentistry [17, 18, 19].

Artemisia sieberi is an aromatic and medicinal plant commonly used to treat diabetes mellitus, coughs, colds, and wound healing. It also has antibacterial and antifungal properties [20]. A study reported that oil extract from the aerial parts of Artemisia had antifungal activity against candida albicans [21]. The primary ingredients of Artemisia sieberi are alpha-thujone and beta-thujone camphor, which are most likely the cause of the plant’s anti-candida effectiveness [22].

Therefore, this study aimed to evaluate the effect of Artemisia sieberi extracts on the candida growth of acrylic materials fabricated by conventional or digital techniques (CAD/CAM milling and 3D printing). It was hypothesized that the effect of Artemisia sieberi extracts on candida growth would not vary between conventional and digitally fabricated denture materials.

2. Materials and methods

2.1 Acrylic resin disc dimension and preparation

Ten acrylic resin discs (3 mm thickness $\times$ 10 mm diameter) were prepared by conventional, CAD/CAM milling or 3D printing. The sample size was in accordance with previous studies [1, 4, 5, 12]. Using CAD software (Zenotec, Wieland Dental, Ivoclar Vivadent, Germany), a standard disc design for each fabrication technique was designed and saved as an STL file (Fig. 1).

Figure 1.

a) STL file designed using CAD software.

Figure 2.

a) PMMA blanks, b) CAD/CAM milling PMMA blank.

Figure 3.

a) 3D printer, b) 3D printing of discs by stereolithography.

The conventional heat-cured acrylic discs were prepared using the lost-wax technique via the flask-press-pack method [23]. The wax pattern of predetermined dimensions was initially crafted to create gypsum molds. Following gypsum impressions, the molds were produced within flasks (Type 4, Dentona, Germany). Then, the flasks were immersed in boiling water to allow the wax to melt and create the gypsum mold. A mixture of PMMA polymer and liquid monomer (MelioDent, Kulzer; Germany) was mixed according to the manufacturer’s recommendations and packed into the mold. After packing, any excess acrylic was removed by placing the flask in a flask pressor (Hydraulic press, Silfradent, Italy). Then, the flask was immersed in boiling water (100^∘C) for an hour to allow heat polymerization of the acrylic material. The obtained heat polymerized discs were finished and polished per the manufacturer’s instructions [1].

In the CAD/CAM milling technique, pre-polymerized PMMA blocks (Wieland, Ivoclar Vivadent, Germany) (Fig. 2a) were milled using a milling machine (Zirkonzahn, Neuler, Germany) (Fig. 2b). The milled discs were then subjected to finishing and polishing procedures as per the manufacturer’s recommendations [4]. For the fabrication of 3D-printed discs, photopolymerised resins (Denture 3D $+$ , Nextdent, Soesterberg, The Netherlands) and a 3D printer (Satori ST1600, London, UK) (Fig. 3a) were utilized. The discs were printed layer by layer at a thickness of 50 $\mu$ m and an angle of 45^∘ using the reference STL file by mask stereolithography technique (Fig. 3b). The printing direction was in agreement with previous studies, which have demonstrated better precision and accuracy of the denture materials printed at 45^∘ [24, 25, 26]. The printed discs were cleaned by immersion in 99.9% isopropyl alcohol for 5 minutes. Then, the discs were subjected to additional polymerization and cured using a light curing device (Zyrlux, Ivoclar Vivadent, Schaan, Liechtenstein).

Figure 4.

Prepared specimens after finishing and polishing.

All prepared discs were finished using silicon carbide abrasive paper (600 grit; Dentaurum, Ispringen, Germany) complemented by water coolant. Next, the discs were polished using water and pumice in a rotary polishing machine (Derotor, London, England) [5, 12]. The polished discs (Fig. 4) were stored in distilled water for 24 hours before roughness measurement.

2.2 Surface roughness measurement

The surface roughness of the acrylic discs was performed at baseline and after post-treatment. The acrylic discs were scanned using an optical profilometer programmed with Vision 64 software (Contour GT-K 3D, Bruker^®, Germany). Vertical scan interferometry was applied with specific parameters, including a 1 mm $\times$ 1 mm scanning field, Gaussian regression filter, Michelson lens (5 $\times$ ), scan speed of 1 $\times$ , and a threshold of 4 [27]. Each disc was scanned at three different positions, and the average roughness value (Ra) was calculated.

2.3 Toothbrushing and thermocycling

In closely simulating the clinical conditions, the resin discs were subjected to a routine denture care process of toothbrushing, thermocycling, and immersion in Artemisia sieberi extract. For the mechanical brushing, the discs were placed in a toothbrush simulator (ZM-3.12, SD Mechatromik GmbH, Germany). The discs were brushed using a soft toothbrush (Colgate-Palmolive Company, Saudi Arabia) with a vertical load of 200 grams and 356 brush strokes per minute in a container containing a mixture of distilled water and locally available dentifrice (Colgate-Palmolive Company, Saudi Arabia). The discs underwent a total of 17,800 brushing cycles over a 50-minute duration.

After brushing, the resin discs were placed in a thermocycling unit (SD Mechatronik, Feldkirchen-Westerham, Germany). One thousand cycles were performed in distilled water with temperatures between 5^∘C and 55^∘C; each cycle consisted of a 30-second dwell time and a 12-second transfer time. The brushing and thermocycling duration applied in this study was per a previous study [5, 12].

2.4 Preparation of Artemisia sieberi extract

Figure 5.

Process of Artemisia sieberi extract.

Water extracts were meticulously prepared from the leaves of Artemisia sieberi – a distinct container combined 300 mL of distilled water with 30 g of the prepared powder. The amalgamation was homogenized for one day using an orbital shaker (MaxQ 2000, Fisher Scientific, Vantaa, Finland). Following this, the mixture underwent filtration through centrifugation at 2000 rpm for 15 minutes. Subsequently, the extracts were concentrated and subjected to drying under reduced pressure and at a temperature of 40^∘C utilizing a rotary evaporator (Büchi^® Rotavapor^® R-210, Merck KGaA, Darmstadt, Germany). The filtered extracts were stored in aseptic glass bottles at four ^∘C until use. The procedure of Artemisia sieberi extract is presented in Fig. 5.

To obtain a 10% concentrate solution, sterile extracts were meticulously mixed with sterile distilled water. The reconstituted aqueous extracts were then carefully passed through 0.45 $\mu$ m bacterial filter papers (Millipore Inc., Riyadh, Saudi Arabia) before being utilized in in-vitro studies. Each acrylic disc sample was soaked in 2 mL of the filtered extract in a sterile centrifuge tube for 8 hours, representing the overnight soaking of denture acrylic material. To recreate the conditions akin to overnight denture immersion, the discs were immersed in the Artemisia sieberi extract solutions and placed in an incubator (Thermo Scientific Heraeus^®, Waltham, MA, USA) pre-set to a temperature of 25^∘C. An incubation period of 8 hours was designated to accurately emulate room temperature storage conditions.

Following incubation, the discs were disinfected with 70% isopropyl alcohol spray in combination with UV light exposure (The Baker Company, Sanford, ME, USA). The disinfected discs were placed in 24-well tissue culture plates (SPL Life Sciences Co., Ltd., Gyeonggi-do, Korea).

2.5 Preparation of candida suspension

Fresh candida from the subculture was combined with 10 ml of sterilized distilled water in three tubes to prepare candida suspension. The mixture was vortexed for 2 minutes using a machine (Labline Equipment Pvt Ltd., Gujarat, India). A nutrient broth solution was prepared by dissolving 0.78 g of nutrient broth (Scharlau, Barcelona, Spain) in 60 ml of distilled water, followed by autoclaving at 121^∘C for 15 minutes.

2.6 Assessment of candida colonization

Each well in the tissue culture plates received 20 $\mu$ L of the candida suspension via a pipette (Transferpette^®S, Brand GMBH $+$ Co KG, Germany) and 2 ml of nutrient broth. The plates were then incubated at 37^∘C for 72 hours. After incubation, the discs were briefly soaked in a 1 $\times$ phosphate-buffered saline (PBS) for 2 seconds. The 1 $\times$ buffered PBS solution was prepared by mixing 16 g NaCl, 0.40 g KCl, 2.8 g Na2HPO4, and 0.49 g KH2PO4 (Sigma-Aldrich, St. Louis, MO, USA) in 200 mL of deionized water, resulting in a 7.4 pH buffer solution. This solution was further diluted from $\times$ 10 to $\times$ 1 and autoclaved.

The discs were transferred to 2 ml of sterilized distilled water in centrifuge tubes and vortexed for 2 minutes. Subsequently, four dilutions were prepared for each disc by adding 900 $\mu$ L of sterile distilled water to each dilution. Using a pipette, 100 $\mu$ L of the first dilution was transferred to the second, and the same process was repeated for the third and fourth dilutions. From each disc’s third and fourth dilutions, 100 $\mu$ L were aspirated and spread onto sabouraud dextrose agar plates (Neogen Corporation, Scotland, UK). These agar plates were then incubated at 37^∘C for 72 hours. Candida growth was assessed by counting colony-forming units (CFUs), and the number of adherent cells was quantified in CFU/mL (Fig. 6).

Figure 6.

Candida growth (CFU/mL) at $\times$ 3 and $\times$ 4 dilutions.

2.7 Statistical analysis

The data were subjected to statistical analysis via Statistical Package for the Social Sciences software v.22 (IBM Corp., Armonk, NY, USA). The roughness and CFU descriptive statistics were expressed as mean and standard deviation (SD). A paired sample $t$ -test was used to determine the significant difference between pre- and post-immersion roughness. One-way analysis of variance (ANOVA) followed by Tukey’s post-hoc multiple comparisons tests was applied to analyze the significant difference in CFU between the acrylic materials ( $\alpha\leqslant$ 0.05).

3. Results

3.1 Surface roughness (Ra)

Table 1 presents the mean and SD of pre-immersion and post-immersion Ra values for the tested acrylic materials. For the conventional discs, the pre-immersion mean Ra was 0.967 $\pm$ 0.452, and the post-immersion mean Ra increased to 1.493 $\pm$ 0.951. In milled discs, the pre-immersion mean Ra was 0.703 $\pm$ 0.59, and the post-immersion mean Ra increased to 1.224 $\pm$ 0.434. For 3D printed discs, the pre-immersion mean Ra was 0.701 $\pm$ 0.404, and the post-immersion mean Ra surged to 1.781 $\pm$ 0.516. The paired sample $t$ -test to compare the pre-to post-immersion Ra demonstrated significant differences in Ra for all three materials ( $p<$ 0.05).

Table 1
Mean and SD of the pre-and post-immersion roughness of the tested acrylic materials

[height=1cm,width=2.6cm]Material typeRoughness	Pre-immersion roughness	Post-immersion roughness	$p$ -value
Conventional	0.967 $\pm$ 0.452^a	1.493 $\pm$ 0.951^a	$<$ 0.001^*
Milled	0.703 $\pm$ 0.590^b	1.224 $\pm$ 0.434^b	$<$ 0.001^*
3D printed	0.701 $\pm$ 0.404^b	1.781 $\pm$ 0.516^c	$<$ 0.001^*

^*The mean difference is significant at the 0.05 level (paired $t$ -test). Different lower case in a column indicates significantly different values between the comparison groups ( $p<$ 0.05).

The comparison of pre-immersion Ra values between the materials showed significant differences in Ra between conventional and CAD/CAM group ( $P<$ 0.05), while no significant difference was found between the CAD/CAM groups ( $p=$ 0.657). On the contrary, the comparison of post-immersion Ra values between the materials showed significant differences in Ra between the tested material groups ( $p<$ 0.05).

3.2 CFU

Table 2
Mean and SD of CFU/mL of the tested acrylic material at $\times$ 3 dilution

Materials	Mean $\pm$ SD
Conventional	72.10 $\pm$ 17.23^a
Milled	20.70 $\pm$ 9.15^b
3D-printed	56.50 $\pm$ 32.20^a

^*The mean difference is significant at the 0.05 level. Same lower case in a column indicates non-significantly different values between the groups ( $p>$ 0.05).

Table 2 represents the mean and SD of CFU/mL of candida albicans for the tested acrylic materials at $\times$ 3 dilution. Conventional discs had the highest mean CFU/mL (72.10 $\pm$ 17.23), and milled discs had the lowest mean CFU/mL (20.70 $\pm$ 9.15) among the tested materials. The mean CFU/mL of 3D printed discs was 56.50 $\pm$ 32.20. Tukey’s post hoc test revealed a statistically significant difference in mean CFU/mL between conventional and milled discs ( $p<$ 0.05), as well as between milled and 3D-printed discs ( $p<$ 0.05). However, the mean CFU/mL between conventional and 3D-printed discs was not statistically significant ( $p>$ 0.05).

Table 3

Mean and SD of CFU/mL of the tested acrylic material at $\times$ 4 dilution

Materials	Mean $\pm$ SD
Conventional	32.80 $\pm$ 6.59^a
Milled	7.75 $\pm$ 3.16^b
3D-printed	16.95 $\pm$ 7.59^b

^*The mean difference is significant at the 0.05 level. Same lower case in a column indicates non-significantly different values between the groups ( $p>$ 0.05).

Table 3 represents the mean and SD of CFU/mL of candida albicans for the tested acrylic materials at $\times$ 4 dilution. Similar to $\times$ 3 dilution, conventional discs had the highest mean CFU/mL (32.80 $\pm$ 6.59), followed by 3D printed discs (16.95 $\pm$ 7.59), and milled discs had the lowest mean CFU/mL (7.75 $\pm$ 3.16) among the tested materials. Tukey’s post hoc test revealed a statistically significant difference in mean CFU/mL between conventional and milled discs and conventional and 3D-printed discs ( $p<$ 0.05). However, the mean CFU/mL between milled and 3D-printed discs was not statistically significant ( $p>$ 0.05).

Pearson correlation analysis was performed to find out any association between the Ra and CFU. At $\times$ 3, Ra and CFU were found to be moderately positive and non-significantly correlated ( $R=$ 0.664, $p=$ 0.149). At $\times$ 4, Ra and CFU were found to be weak positive and non-significantly correlated ( $R=$ 0.344, $p=$ 0.503).

4. Discussion

With the rise in digital dentistry, utilization of digital technologies is becoming feasible and more familiar to adopt. Digital technologies also help to produce a more successful prosthetic treatment with less time and a more predictable results [28]. Dentures constructed using CAD/CAM technology have shown a decently acceptable clinical results and allowed shorter construction time and a smaller number of appointments resulting in a more satisfactory results to the dentist and the patients as well [1, 5, 12]. The properties and the long-term effects of using denture acrylic materials constructed using CAD/CAM technology to the oral environment are still not fully understood and studied compared to conventionally fabricated denture acrylic materials. The current study evaluated the effect of Artemisia sieberi extracts on candida growth of acrylic materials fabricated by conventional or digital techniques (CAD/CAM milling and 3D-printing). It was hypothesized that the effect of Artemisia sieberi extracts on candida growth would not vary between conventional and digitally fabricated denture materials. Based on the study outcomes, the null hypothesis was partially rejected.

This study revealed that the pre-immersion Ra was lower in CAD/CAM acrylic material compared to conventional heat-cured acrylic, aligning with prior studies that found similar outcomes [6, 7, 9]. Al-Dwairi et al. [6] studied the surface properties of CAD/CAM acrylic resins and conventional heat-polymerized acrylic resins and found that CAD/CAM acrylic resins had smoother surfaces than conventional heat cured acrylic. Similarly, Wei et al. [7] evaluated surface properties and microbial adhesion of conventional heat cured acrylic resin, CAD/CAM acrylic resin, temporary polymers made with CAD/CAM and conventional technique, and denture framework polymers made by CAD/CAM and conventional method. The study found increased surface roughness in all groups except CAD/CAM acrylic resin and they also found less candida adhesion in CAD/CAM acrylic compared to conventional heat cured acrylic. This can be attributed to the complex fabrication process and manufacturing errors that can occur in the conventional heat cured acrylic denture construction [29]. On the contrary, CAD/CAM resins have better physical and mechanical properties compared to conventional resins [30, 31]. They have shown higher elastic modulus, young’s modulus, ultimate strength, yield point, strain at yield point, and toughness [6]. Additionally, CAD/CAM resins have demonstrated improved surface properties, including lower surface roughness compared to conventional resins [6, 9, 30, 31, 32]. These findings suggest that dentures made with CAD/CAM PMMA resin are expected to be more durable and have better clinical performance [33].

When the acrylic discs were soaked in Artemisia sieberi extract, the post-soaking Ra was significantly higher than the pre-soaking values in all groups. This might be partially attributed to the acidic nature of some chemical components in the extract, including monoterpene alcohols, representing about 80% of the extract [21]. However, the increase in post-soaking Ra does not completely reflect the negative effect of Artemisia sieberi on the surface roughness of the acrylic materials. It is very important to recall that the specimens were subjected to aging by thermocycling and brushing before soaking in the extract, which could have also led to surface irregularities and a rougher surface rather than the Artemisia sieberi extract alone. Previous studies have demonstrated an increased roughness of the polymeric materials subjected to thermocycling and toothbrushing [4, 5, 12, 27].

The antifungal effect of Artemisia sieberi extract is well-established [20, 22, 34]. A study conducted to evaluate the effectiveness of artemisia mouthwash against denture stomatitis showed significant decrease in the scores of candida colony growth [22]. Similalry, Abu-Darwish et al. [34] confirmed the antifungal activity of Artemisia sieberi essential oil with 1,8-cineole (20.1%), b-thujone (25.1%), a-thujone (22.9%) and camphor (10.5%) against different candida species (C. albicans, C. parapsilosis, C. tropicalis, C. guilliermondii, C.krusei). In a more recent study, Amal and Ayal [20] evaluated the impact of ethanol and oil extracts from aerial parts of Artemisia on the growth of Candida albicans and the shear bond strength of soft denture liners. The authors concluded that both extracts demonstrated antifungal properties. However, ethanol extract showed an improvement in the bond strength while oil extract had no effect.

The variation in candida adhesion was evaluated using the CFU count, which measures cell adherence to the denture base [35]. The conventional heat cured acrylic showed the highest CFU in both dilutions compared to CAD/CAM acrylic materials. This is in accordance with a previous study that investigated the candida adhesion in CAD/CAM acrylics with or without the presence of a salivary pellicle [16]. The authors found that CAD/CAM acrylic materials had less initial candida adhesion than conventional heat-cured acrylic. Among the CAD/CAM denture acrylic materials, milled specimens showed lower CFU count compared to 3D printed acrylics. Similar such outcomes have been reported in previous studies comparing candida adhesion between milled and 3D-printed surfaces [16, 36, 37, 38]. Milled dentures have demonstrated better properties than 3D printed dentures in terms of trueness, precision, dimensional accuracy, impact and flexural strength and roughness [39, 40, 41, 42, 43]. Overall, CAD-CAM milled denture acrylic materials demonstrated better resistance to candida adhesion than the conventional and 3D-printed acrylic making it a preferable choice for reducing candida-associated denture stomatitis. These results suggest that the type of acrylic material has a significant impact on CFU/mL.

The difference in CFU between the three materials could be attributed to material properties and fabrication techniques. The drawbacks of conventional acrylic resin fabrication such as air trapped during mixing, incomplete polymer and monomer mixing, residual monomer, and insufficient flask compression can fundamentally influence the adherence of microorganisms and promote their colonization on the denture surface [44]. In 3D printing, the specimens are printed layer by layer, and the stepwise connection between the printing layers creates deeper grooves and more porosities on the surface [45]. These surface irregularities could have contributed to an increased candida adhesion of the 3D-printed group. One more reason for increased CFU of the conventional and 3D printed groups is the polymerization shrinkage. Furthermore, polymerization shrinkage may theoretically occur during the 3D printing process since dentures are partially polymerized before the final light-polymerization process [41].

On the contrary, there are few dimensional alterations with the CAD-CAM milled dentures as they are made from a homogenous disc manufactured at high pressure and temperature. The superior performance of milled dentures over conventional heat-processed and 3D-printed dentures could also be attributed to the polymer’s longer chain, which results in a higher degree of monomer conversion [42, 46]. Consequently, the denture bases produced using CAD/CAM milling exhibit a smoother and less porous surface than the other two material surfaces [44]. It is noteworthy to remember that the roughness of 3D printed group was significantly high but still they exhibited lower CFU count than the conventional group. The surface free energy of the 3D printed groups may be more likely associated with the CFU count than their surface roughness [47].

The current study has limitations. Firstly, this was an in-vitro study where the effect of the oral environment was not considered. The anti-bacterial and cleansing effects of saliva and patient factors, including age, medical condition, and adjuvant denture care regimen, were not considered. Secondly, the toothbrushing and aging were performed individually and continually to represent one year of clinical use. In contrast, in the oral environment, these actions co-occur daily. Finally, the specimens’ surface roughness was obtained after aging, toothbrushing, and soaking in Artemisia sieberi extracts. The specific effect of the extract on the specimen’s roughness was not tested.

Future research should evaluate the prolonged use of Artemisia sieberi extracts and the impact of these extracts on the surface topography of both conventional and CAD/CAM fabricated acrylic materials in addition to their toxicity evaluation. It would also be interesting to incorporate this extract to the denture base materials and developing extract based denture cleansing solution for clinical use. Long-term studies should evaluate the sustained antifungal efficacy of Artemisia sieberi extracts over time, simulating actual clinical denture wear conditions. Furthermore, observing the effect of Artemisia sieberi extracts on other microbial species commonly associated with denture stomatitis would be interesting, providing a broader understanding of its antimicrobial potential.

5. Conclusion

The Artemisia sieberi extracts have a notable impact on digitally processed denture acrylic materials, leading to reduced candida growth compared to conventional acrylic resins. These findings provide valuable insights into the potential benefits of CAD/CAM technology in denture fabrication and its role in enhancing oral health by minimizing candida growth and improving surface properties. However, further research, including clinical studies, is necessary to fully understand the clinical implications of these findings.

Footnotes

Conflict of interest

None to report.

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Assessing the effect of Artemisia sieberi extracts on surface roughness and candida growth of digitally processed denture acrylic materials

Abstract

BACKGROUND:

OBJECTIVE:

METHOD:

RESULTS:

CONCLUSION:

Keywords

1. Introduction

2. Materials and methods

2.1 Acrylic resin disc dimension and preparation

2.3 Toothbrushing and thermocycling

2.4 Preparation of Artemisia sieberi extract

2.6 Assessment of candida colonization

3. Results

3.1 Surface roughness (Ra)

Table 1 Mean and SD of the pre-and post-immersion roughness of the tested acrylic materials

Table 2 Mean and SD of CFU/mL of the tested acrylic material at × 3 dilution

5. Conclusion

Footnotes

Conflict of interest

References

Table 1
Mean and SD of the pre-and post-immersion roughness of the tested acrylic materials

Table 2
Mean and SD of CFU/mL of the tested acrylic material at $\times$ 3 dilution