Soft Lining Materials Research Articles

Comparison of Adhesion of Soft-Liner between Conventional PMMA and 3D Printed Resin Denture Bases

Aims: The purpose of this study was to evaluate the tensile strength of the soft-liner (Molloplast-B®) between the denture foundation made of 3D printed resin and traditional acrylic (PMMA). Materials and Methods: In this experiment, 60 acrylic specimens in the shape of reverse dumbbells were employed. The first group consisted of 24 specimens made from traditional acrylic polymethyl methacrylate (PMMA) (Vertex, Veracril, and Duradent) while the second group consisted of 24 specimens made from 3D printed resin (Dentona). The third group consisted of 12 samples that were packed at the dough stage of acrylic and soft liner at the same time. After that, the samples from the first and second groups were split in two, with one half receiving no surface treatment and the other half undergoing sandblasting. Every sample is separated into two halves with precise measurements. The thickest and thinnest sections were 80 mm in length (10 mm x 25 mm) and 8 mm x 15 mm, respectively, and were joined in the middle by the soft-liner material. The experiment's tensile strength was examined in two separate directions to ascertain the soft-liner material's strength of adhesion to the sample's chosen materials. Results: The data analysis of the tensile strength test revealed a statistically significant difference in the soft-liner adhesion strength between the 3D-printed acrylic resin with sandblast treatment (0.2133 ± 0.03939 kN/mm²) and the 3D-printed acrylic resin without surface treatment (0.1567 ± 0.04677 kN/mm²). Similar results were observed for conventional acrylic PMMA, where the sandblasted acrylic PMMA (0.0950 ± 0.03606 kN/mm²) exhibited significantly better bond strength compared to the untreated acrylic PMMA (0.0875 ± 0.02491 kN/mm²). Dough stage samples had better values complared to traditional acrylic (0.1483± 0.03689 kN/mm²). Conclusion: The results demonstrate that sandblast treatment significantly improves the soft-liner adhesion strength of both 3D-printed acrylic resin and conventional acrylic PMMA. Surface treatment enhances bond strength compared to untreated materials. These findings suggest that sandblasting is an effective method for improving adhesion in acrylic-based materials.

Development of an antimicrobial tissue conditioner with quaternary ammonium methacryloxy silane (K18): An in vitro study

To determine the effects of K18 quaternary ammonium methacryloxy silane (QAS) on tissue conditioner materials and their antimicrobial properties. 30% K18 QAS in methyl methacrylate (MMA; K18-MMA; 0%, 15%, and 20% w/w) was incorporated into a commercial tissue conditioner (Coe comfort). The degree of curing (Shore A hardness), hydrophilicity (contact angle), flow, liquid sorption, mass loss, and antimicrobial properties of Streptococcus mutans, Streptococcus sanguinis, and Candida albicans were determined. Statistical analysis included analysis of variance with Tukey HSD and Kruskal-Wallis with Bonferroni correction. Hardness increased significantly at higher K18-MMA concentrations. The contact angles did not differ between the groups. Although the control and K18-containing tissue conditioner flow decreased significantly at each successive time point and with increasing K18 QAS MMA concentration, the flow was still within the ISO 10139-1 specifications for class 2 (high-flow) soft lining materials until 2 min 30 s. The highest liquid sorption happened between 1 and 4 weeks. The controls absorbed more acid than water or base, and the K18 groups absorbed more water and acid than base. With increasing K18-MMA concentration, the mass loss increased at all times and in all three media, except in base, after 4 weeks. Both 15% and 20% K18-MMA showed significant antimicrobial activity against S. mutans, S. sanguinis, and C. albicans. K18-MMA imparted significant antimicrobial properties to tissue conditioners against S. mutans, S. sanguinis, and C. albicans without compromising the flow, hardness, or hydrophilicity. However, K18-MMA addition led to increased water sorption and mass loss after 4 weeks.

The Effect of Various Surface Treatment on the New Digitally Manufactured Materials Versus the Conventional Materials – In Vitro Study

Background: Clinical benefits of resilient denture liners have been recognized in prosthodontic practice for many years. The elastic behavior of the soft lining materials is designed to distribute functional and non-functional stress on denture-supporting tissues. Materials and Methods: A total of 30 dumbbell-shaped test specimens were prepared from two different heat cure denture base materials. They are divided into two groups. Group (A) was prepared from heat cure poly-methylmethacrylate resin (PMMA) and Group (B) was prepared from computeraided design and computer-aided manufacturing (CAD/CAM) acrylic resin denture base material. A temporary soft-liner type was used. The denture base specimens of (Group A and Group B) were subdivided equally into three subgroups. 3 mm was marked and sectioned on the specimens with fissure burs and removed to create a uniform space for the application of soft liner. The interface surface of each specimen and the denture base resin surface were conditioned by three surface treatment modalities: 1 – specimens were polished using silicone carbide papers of grit size, 2 – using air abrasion by 50 μm aluminum oxide particle, 3 – by application of 3 M Scotchbond dental adhesive. Tensile bond strength (TBS) was tested for the specimens of each subgroup after thermocycling. Results: The mean of TBS of subgroup (A3) and subgroup (B3) specimens treated with 3M Scotch bond was significantly higher than the other subgroups. Conclusion: The surface treatment of PMMA and CAD/CAM denture base specimens with primer followed using an adhesive bond of 3M Scotch bond had an effective and superior TBS.

Review of the Anti-Candida albicans Activity and Physical Properties of Soft Lining Materials Modified with Polyene Antibiotics, Azole Drugs, and Chlorohexidine Salts.

This review examined the current state of knowledge on the modifications of commercial soft lining materials (SLMs) with a variety of antifungal compounds: (i) polyene antibiotics, including nystatin and amphotericin B, (ii) azole drugs, including fluconazole, itraconazole, clotrimazole, ketoconazole, and miconazole, and (iii) antiseptics, including chlorhexidine salts to give them anti-Candida albicans properties. The effect of such modifications on the SLMs' physical properties, such as drug release, water sorption, surface properties, bond strength, tensile strength, and hardness, was also analyzed. In effect, this study provided a unique compilation of research results obtained for numerous properties of SLM modified with antifungal compounds that differ in their chemical structure and mechanism of antifungal action. These results might also be useful for prosthetic dentistry, where SLMs are used to prevent and treat candidiasis, the most common disease among denture wearers.

Evaluation of Tensile Bond Strength of Nanoparticle Reinforced Soft Liner Materials: A Pilot Study

OBJECTIVE: The aim of this study is to evaluate the tensile bond strength between polymethyl methacrylate (PMMA) surfaces and autopolymerized silicon-based soft lining materials with 1% w/w Titanium dioxide (TiO2) and Hydroxyapatite (HA) nanoparticles added. MATERIALS AND METHODS: For the tensile test, 60 pieces of acrylic (Meliodent, Bayer Dental, Newbury, England) samples of 30 × 10 × 10 mm3 dimensions were prepared using metal molds. Acrylic surfaces were sanded with silicon carbide sandpapers of 500, 1000, 1500, and 2000 grids to ensure standardization. After the samples were placed back in the metal mold, adhesive (Detax, Germany) was applied to the surfaces that would come into contact with the soft lining. Soft lining materials (Mollosil, Detax, Ettlingen, Germany) to which 1% by weight TiO2 and 1% HA nanoparticles were added were polymerized by placing them between two acrylic blocks. For the tensile test, a total of 30 samples were obtained, with 10 samples in each group (n=10). The specimens were placed on the holder end of the universal test device and force was applied until failure occurred. RESULTS: The tensile bond strength (0,86 ± 0,21 MPa) in the TiO2 nanoparticle-added group was found to be significantly higher than the control group (0,65 ± 0,14 MPa) (p<0.05). There is no significant difference between the control group and the HA nanoparticle-added group (0.65 ± 0.1 MPa) (p˃0.05). CONCLUSION: It was observed that the addition of nanoparticles increased the tensile strength. However, further studies are needed to evaluate the effect of nanoparticle addition on other mechanical and physical properties of soft liners.

Comparison of Bond Strength of Soft Denture Liner on the Denture Base Materials Produced by Different Methods and Effect of Thermocycling

Aim: This study set out to determine the tensile bond strength between denture bases (produced by 3D printing technology, conventional technique, and computer-aided design and computer-aided manufacturing [CAD/CAM] milled) and silicone-based soft lining material. The consequence of thermocycling on the bonding strength was also investigated. Materials and Methods: The bonding between denture foundation materials produced through three distinct techniques (conventional, CAD/CAM milled, and 3D printed) and silicone-based soft lining material was examined. Before tensile testing, half of the samples underwent thermocycling (5–55°C, 5,000 cycles) in 37°C distilled water for 48 hours. A universal testing apparatus employed a crosshead speed of 5 mm/min. The failure type was identified visually, and the maximum tensile strength was noted. The Shapiro-Wilk test and analysis of variances ( P = .05) were used to assess the statistics. Results: CAD/CAM milled denture base material (1.56 ± 0.62/1.36 ± 0.16 MPa) showed higher bond strength values than the other denture bases in the tensile test conducted before and after thermocycling ( P < .001). The denture base material made conventionally had the lowest bond strength (1.02 ± 0.24/0.77 ± 0.1 MPa) ( P < .001). The tensile bond strength values of the conventional and 3D printing groups showed a statistically significant drop before and after thermocycling ( P = .001). Regardless of thermocycling, adhesive failure was primarily seen in all groups (76.6%). Conclusion: Compared to conventionally produced denture bases, the bond strength of soft relining materials to CAD/CAM milled and 3D printed denture base is different. In denture base materials that are conventionally, CAD/CAM and 3D printed, the thermocycling method reduced bonding strength values.

In vitro analysis of a novel dimethylaminododecyl methacrylate modification of dental acrylic soft liner material

Soft denture liners have limitations like short lifespan and increased microbial buildup. Despite promise as a non-leaching antimicrobial polymer in dentistry, the impact of dimethylaminododecyl methacrylate (DMADDM) on soft liner performance remains unexplored. This study aimed to evaluate the effect of integrating different concentrations of DMADDM to cold cure acrylic resin soft liner, on its antimicrobial activity, cytotoxicity, and physical properties. The same properties were compared to a conventional commercially available denture soft liner. The study employed a control group (conventional soft liner) and three test groups containing 3.3%, 6.6%, and 10% (total mass fraction) DMADDM, respectively. Antimicrobial activity against Candida albicans and Streptococcus mutans was assessed through colony counts and biofilm biomass. Cytotoxicity was evaluated using an oral epithelial cell line. Additionally, wettability and hardness were measured to assess physical properties. Incorporation of DMADDM significantly reduced Candida albicans and Streptococcus mutans counts, and biofilm biomass, compared to the control. Additionally, DMADDM improved the soft liner's wettability and mitigated long-term hardness increase. In conclusion, DMADDM holds promise in enhancing soft liner performance. However, careful selection of its optimum concentration is crucial to ensure both safety and efficacy for future clinical use.

Comparison of Tensile Bond Strength of Soft Denture Liner Material on Denture Base Resins

Aim: This study aims to evaluate the tensile bond strength (TBS) of a silicone-based soft denture liner material on denture bases produced via conventional, subtractive, and additive manufacturing techniques and examine the effect of aluminum oxide particle abrasion (APA) on TBS. Material and Methods: A total of 48 cylindrical denture base resin samples were manufactured using three different techniques: conventional, subtractive, and additive manufacturing. The samples were divided into two groups: control and APA. All samples were separated at the center, and the soft liner was applied to the corresponding surfaces. The specimens then underwent TBS testing. Data were analyzed using Two-way ANOVA and Bonferroni post hoc tests. Results: Two-way ANOVA results indicated a significant difference among the denture base resins, while no significant difference was found between the control and APA groups. The highest TBS was observed in the subtractive-manufactured APA group, while the lowest TBS was in the additive-manufactured APA group. Significant differences were found between the subtractive and additive-manufactured groups (p=0.022). Conclusion: This study demonstrates that TBS varies with the DB's manufacturing technique. While APA increased TBS in subtractive manufacturing, it had no statistically significant effect. Further research should explore different soft lining materials and consider in vivo conditions for more comprehensive insights.

Evaluation of Peel Bond Strength between Heat Cured Acrylic Based Denture Soft Lining Material and Heat Polymerized Acrylic after Different Acrylic Surface Treatment Methods

Evaluation of Peel Bond Strength between Heat Cured Acrylic Based Denture Soft Lining Material and Heat Polymerized Acrylic after Different Acrylic Surface Treatment Methods

Impact of Cerium Oxide Nanoparticles Incorporation on Water Sorption and Solubility of Acrylic-Based Denture Soft Lining Material

Denture soft liners are specifically engineered to enhance patient performance by altering the surfaces of prosthetics that come into touch with the soft tissues within the oral cavity. Acrylic resin Polymethyl methacrylate (PMMA) based and silicone elastomer-based are the two main types of denture soft liners. Nanotechnology was employed as a means to enhance the mechanical qualities of dentures. The primary objective of this investigation was to examine the impact of cerium oxide (CeO2) nanoparticles (NPs) on the water sorption and solubility characteristics of acrylic-based soft liners. The data was subjected to analysis of variance (ANOVA). The surface characteristics were determined using scanning electron microscopy (SEM). This in vitro study demonstrates that including CeO2 NPs at 2% and 3% concentrations does not impact acrylic-based soft lining materials' water sorption and solubility. The solubility of CeO2 is well-recognized to be very low. The results indicated that there were no statistically significant differences between the groups.

Evaluation of rheological properties of soft lining materials with different composition under various temperatures

PurposeThe aim of this in vitro study was to evaluate the changes the rheological properties of some soft lining materials, to compare the rheological properties and viscoelastic behaviour at different temperatures.Materials and methodsFive soft lining materials (acrylic and silicone based) were used. the storage modulus (G’), loss modulus (G”), tan delta (tan δ) and complex viscosity (η’) were chosen and for each material, measurements were repeated at 23, 33 and 37 °C, using an oscillating rheometer. All data were statistically analyzed using the Mann Whitney U test, Kruskal Wallis test and Conover’s Multiple Comparison test at the significance level of 0.05.ResultsSoft lining materials had different viscoelastic properties and most of the materials showed different rheological behavior at 23, 33 and 37 °C. At the end of the test (t¹5), at all the temperatures, Sofreliner Tough M had the highest storage modulus values while Visco Gel had the highest loss Tan delta values.ConclusionsThere were significant changes in the rheological parameters of all the materials. Also temperature affected the initial rheological properties, and polymerization reaction of all the materials, depending on temperature increase.Clinical implicationsTemperature affected the initial rheological properties, and polymerization reaction of soft denture liner materials, and clinical inferences should be drawn from such studies conducted. It can be recommended to utilize viscoelastic acrylic-based temporary soft lining materials with lower storage modulus, higher tan delta value, and high viscosity in situations where pain complaint persists and tissue stress is extremely significant, provided that they are replaced often.

Investigation of the Effect of Denture Cleaning Solutions on Surface Hardness and Surface Roughness of Soft Lining Materials

Aim: The purpose of this study is to investigate the effects of commercial and non-commercial agents used to clean dentures on the surface roughness and hardness of two soft lining materials. Material and Methods: A total of 50 samples were used in this study. Samples were prepared from acrylic resin (Visco Gel) and silicone-based (Molloplast B) soft lining materials. The samples’ roughness and hardness values were measured. After the samples were kept in distilled water, white vinegar, denture cleanser tablet, 2% chlorhexidine gluconate, and 5% sodium hypochlorite for 15 minutes, 30 minutes, 45 minutes, 60 minutes, 2 hours, 8 hours, 24 hours, and 48 hours, roughness and hardness values were measured again. Statistical analysis was performed using the computer program SPSS Statistics 20.0 (SPSS Inc. Chicago, IL, USA) at a 95% confidence interval and p=0.05 significance level. Three-way ANOVA and Tukey’s multiple comparison tests were used for the statistical analysis of data. Results: The analysis of variance determined that the material type and time had a very significant effect (p<.001) on surface roughness and hardness values, while the solutions in which samples were kept had an insignificant effect (p>.05). Conclusion: The surface roughness and hardness of acrylic resin and silicone-based soft lining materials were affected by denture cleaning solutions to different extents.

A Temporary Acrylic Soft Denture Lining Material Enriched with Silver-Releasing Filler-Cytotoxicity, Mechanical and Antifungal Properties.

Colonization of temporary denture soft linings and underlying tissues by yeast-like fungi is an important clinical problem due to the negative influence on the process of prosthetic treatment. Typical hygienic procedures are often insufficient to prevent fungal infections, so in this study, an antimicrobial filler (silver sodium hydrogen zirconium phosphate) was introduced into acrylic soft liner at concentrations of 1, 2, 4, 6, 8 and 10% (w/w). The effect of this modification on antifungal properties against Candida albicans, cytotoxicity, Shore A hardness, tensile strength and tensile bond strength, sorption and solubility was investigated, considering the recommended 30-day period of temporary soft lining use. The most favorable compilation of properties was obtained at a 1 to 6% filler content, for which nearly a total reduction in Candida albicans was registered even after 30 days of sample storing. The tensile and bond strength of these composites was at the desired and stable level and did not differ from the results for the control material. Hardness increased with the increasing concentration in filler but were within the range typical for soft lining materials and their changes during the experiment were similar to the control material. The materials were not cytotoxic and sorption and solubility levels were stable.

The Effect of Exposure to Candida Albicans Suspension on the Properties of Silicone Dental Soft Lining Material.

While functioning in the oral cavity, denture soft linings (SL) are exposed to contact with the microbiota. Dentures can offer perfect conditions for the multiplication of pathogenic yeast-like fungi, resulting in rapid colonisation of the surface of the materials used. In vitro experiments have also shown that yeast may penetrate SL. This may lead to changes in their initially beneficial functional properties. The aim of this work was to investigate the effect of three months of exposure to a Candida albicans suspension on the mechanical properties of SL material and its bond strength to the denture base polymer, and to additionally verify previous reports of penetration using a different methodology. Specimens of the SL material used were incubated for 30, 60 and 90 days in a suspension of Candida albicans strain (ATCC 10231). Their shore A hardness, tensile strength, and bond strength to acrylic resin were tested. The colonization of the surface and penetration on fractured specimens were analysed with scanning electron and inverted fluorescence microscopes. Exposure to yeast did not affect the mechanical properties. The surfaces of the samples were colonised, especially in crystallized structures of the medium; however, the penetration of hyphae and blastospores into the material was not observed.

Evaluation of Effect the Incorporation of The Virgin Coconut Oil on Thermal Conductivity of Heat-Cure Acrylic Soft Denture Lining Materials

Background: The main disadvantage of soft liners is the low thermal conductivity between the denture base and soft liner material.Aim: The present study aims to estimate the impact of adding virgin coconut oil (1.5% vol and 2.5% vol) to a soft acrylic liner material in a thermal conductivity test.Material and Methods: For this project, we did 30 pieces of acrylic soft liner material. The specimens were divided into three groups: 10 control group specimens that only contained the soft liner material, 10 specimens mixed with virgin coconut oil at a volume of 1.5% with the soft liner material, and 10 specimens mixed with virgin coconut oil at a volume of 2.5% with the soft liner material. Equipment in the Technologies, Department used to conduct thermal conductivity tests. 40mm diameter and 2.5mm thickness thermal conductivity specimens were prepared.Results: Using static analysis, data showed that the soft liner with the highest thermal conductivity contained virgin coconut oil at a volume of 2.5% compared to the soft liner containing virgin coconut oil at a volume of 1.5%, and the control group, the results revealed p < 0.01.Conclusion: Thermal conductivity is increased when virgin coconut oil (2.5% by volume) is incorporated into the soft acrylic liner material.

Effectiveness of Chitosan versus Natural Aloe Vera on Candida Adherence in Denture Soft Lining Material.

Soft denture lining materials act as a cushion between the denture base and tissues. Alongside having many advantages, its main problem is candida growth due to its rubbery and porous texture. Many interventions have been performed to halt the growth of candida within soft lining materials such as the use of antifungal therapy and strict oral and denture hygiene but there are consequences such as recurrence, drug resistance, and toxicity related to these interventions. Since natural agents such as aloe vera and chitosan have been proven to have antibacterial and antifungal properties with minimum adverse effects, this study aimed to study the effectiveness of chitosan and aloe vera powders incorporated within denture soft lining materials against candida adherence. Methodology. A total of 60 soft-lining material samples were prepared that were equally divided into three groups, viz., group 1 (chitosan incorporation), group 2 (aloe vera incorporation), and group 3 (control). Candida was obtained from the microbiology lab to form a candidal suspension, diluted in 0.9% NaCl to match the McFarland standard bacteriologic solution. Samples were incubated at 37°C for 24 hours in test tubes containing 100 mL of the candidal suspension and 9.9 mL of the previously prepared Sabouraud dextrose agar. Crystal violet stain was used to stain the adhering cells by fixing them with methanol 80%. For each sample, the adhering candida cells were counted on three standard fields by using an inverted light microscope, and the mean of those fields was recorded. The mean value for samples containing aloe vera was 41.15, while the mean values for samples containing chitosan and the control group were 16.05 and 79.1, respectively. Of all the three groups, aloe vera powder had a significant efficacy against candida growth as compared to the chitosan and control groups (P value = 0.001). Both herbal agents were effective against candida growth. In comparison, aloe vera was more effective against candida growth compared to chitosan.

Meko podlaganje imedijatne totalne proteze - prikaz slučaja

Introduction: With the placement of dental implants in edentulous patients, creating and adapting immediate dentures is crucial to allow patients to perform basic physiological functions during the osseointegration period without affecting implant healing. This report presents a case of direct soft lining of immediate complete dentures following implant placement. Case Report: Six dental implants were inserted in the upper jaw, while the patient retained natural teeth in the lower jaw. An immediate complete denture was fabricated and adjusted for the upper jaw. The prosthesis base was prepared and processed to accommodate soft lining material. Adhesive was applied to the prepared base, followed by silicone application for soft fitting onto the prosthesis base, which was then inserted into the patient's mouth. After three minutes, the denture was removed, and soft lining treatment of the immediate complete denture was completed. Conclusion: Direct soft lining facilitated patient adaptation to the immediate prosthesis and supported safer healing and osseointegration until definitive work could be completed. The addition of a soft silicone layer reduced pressure on the residual alveolar ridge and improved adhesion of the immediate prosthesis.

An assessment of the impact of L.Salvadora persica and G.Tea on the surface roughness and hardness of heat-cured acrylic-based denture soft liners.

Background: Soft denture liners are a type of dental prosthesis that functions as a cushioning material, alleviating the stress induced by the act of chewing. They offer relief to persons who encounter discomfort when wearing complete or partial dentures, particularly when these dentures are situated on rigid surfaces that support the denture. The objective of this study: is to assess the effects of including L.Salvadora persica. and green tea (G.Tea) extract powders on the surface roughness and hardness characteristics of acrylic-based soft liners. Materials & Procedures: 30 specimens were constructed using wax molds and acrylic-based heat-cured denture soft lining material. The standard curing procedure was used. The samples were separated into three equal groups: group A, the control group, with no additives in the soft-liner material; group B, with 5.12% weight percept L.salvadora persica extract powder; and group C, with 5.12% weight present green tea (G.Tea) extract powder. The samples were then prepared for surface hardness and roughness testing. Results: The results revealed that there was a non-significant rise in the mean values of surface roughness for both group B and group C, group B having the highest mean values followed by group C. When compared to the control group, the results showed a considerable rise in the mean values of surface hardness in group (B), which had the highest mean value for surface hardness, followed by group (C). Conclusion: The results of this study indicate that the incorporation of L.salvadora persica at a concentration of 1.024g and green tea (G.Tea) extract powders at a concentration of 1.024g shown a positive impact on the surface hardness of denture soft lining materials

Effect of Microwave Energy Disinfection on Roughness of Soft Lining Material

Introduction: Soft lining material enhance the patient’s comfort, its rough surface affect oral health, the risk with soft reliners was difficult hygienic maintenance, sterilization by microwave method more favor compared with chemicals disinfections. Objective to study the effect of disinfection by microwave irradiation at different exposure time on surface roughness of long-term soft-liner material. Material and Methods: 45 Specimens of long-term soft liner were made in the form of square metal shaped pattern. The preparation of mould was done by conventional procedures according to manufacture instruction and divided into three groups: GroupA control (without disinfection), Group B daily disinfection by microwave for 5min at 650W and GroupC daily disinfection by microwave for15min at 650W. The specimens were irradiated daily for 15 days (both group B&C). Roughness measurement were made for three groups by profilometer device and analyzed by ANOVA ‘test. Result show that high mean value surface roughness of long term soft liner after expose to microwave disinfection for 15 min(Group C), and low mean value before expose to microwave disinfection(Group A), there were highly significant differences (P<0.01) among tested groups and there was no significance difference (p>0.05) between control Group with (Group B) 5 min disinfection, while the difference was significance (p<0.05) between (Group C )15 min disinfection with : (Group B) 5 min disinfection and with (Group A )control group. Conclusions: the roughness of long-term soft-liner material was not adversely affected by microwave disinfection at 5 min, there was no significant differences with control group while adversely affected by microwave disinfection at 15 min, there was significant differences with control group also with group 5 min disinfection.

The Impact of the Addition of Vitamins on a Silicone Lining Material to the Oral Mucosa Tissue-Evaluation of the Biocompatibility, Hydrolytic Stability and Histopathological Effect.

Background and Objectives: One's quality of life depends on overall health, and in particular, oral health, which has been and continues to become a public health issue through frequent manifestations in various forms, from simple oral stomatitis (inflammations of the oral cavity) to the complicated oral health pathologies requiring medical interventions and treatments (caries, pulp necrosis and periodontitis). The aim of this study focused on the preparation and evaluation of vitamins (vitamin A, B1 and B6) incorporated into several silicone-based lining materials as a new alternative to therapeutically loaded materials designed as oral cavity lining materials in prosthodontics. Materials and Methods: Silicone-based liners containing vitamins were prepared by mixing them in solution and becoming crosslinked, and then they were characterized using Fourier-transform infrared (FT-IR) spectroscopy to confirm the incorporation of the vitamins into the silicone network; scanning electron microscopy (SEM) to evidence the morphology of the liner materials; dynamic vapor sorption (DVS) to evaluate their internal hydrophobicity, swelling in environments similar to biological fluids and mechanical test to demonstrate tensile strength; MTT to confirm their biocompatibility on normal cell cultures (fibroblast) and mucoadhesivity; and histopathological tests on porcine oral mucosa to highlight their potential utility as soft lining materials with improved efficiency. Results: FT-IR analysis confirmed the structural peculiarities of the prepared lining materials and the successful incorporation of vitamins into the silicone matrix. The surface roughness of the materials was lower than 0.2 μm, while in cross-section, the lining materials showed a compact morphology. It was found that the presence of vitamins induced a decrease in the main mechanical parameters (strength and elongation at break, Young's modulus) and hydrophobicity, which varied from one vitamin to another. A swelling degree higher than 8% was found in PBS 6.8 (artificial saliva) and water. Hydrolytic stability studies in an artificial saliva medium showed the release of low concentrations of silicone and vitamin fragments in the first 24 h, which increased the swelling behavior of the materials, diffusion and solubility of the vitamins. The microscopic images of fibroblast cells incubated with vitamin liners revealed very good biocompatibility. Also, the silicone liners incorporating the vitamins showed good mucoadhesive properties. The appearance of some pathological disorders with autolysis processes was more pronounced in the case of vitamin A liners. Conclusions: The addition of the vitamins was shown to have a beneficial effect that was mainly manifested as increased biocompatibility, hydrolytic stability and mucoadhesiveness with the mucosa of the oral cavity and less of an effect on the mechanical strength. The obtained lining materials showed good resistance in simulated biological media but caused a pronounced autolysis phenomenon, as revealed by histopathological examination, showing that these materials may have broad implications in the treatment of oral diseases.