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Background and Aim: Soft liners are designed to modify the surfaces of prostheses that interact with the mouth's soft tissues to improve denture performance. One method of improving its mechanical properties involved the application of nanotechnology. This work aimed to determine impact of cerium oxide nanoparticles (CeO2NPs) on acrylic-based soft liner's surface hardness and shear bond strength. Materials and Methods: CeO2NPs were added to soft liner monomer with weight percentages of 0%, 2%, and 3%. Sixty samples were prepared for shear bond test and surface hardness test with 30 samples each. Shear bond samples were prepared by constructing two acrylic blocks which assembled over each other creating a square space in the middle with dimensions around 25 mm in length and width and 3 mm in depth for the addition of soft liner material. The surface hardness samples were constructed as a disc with diameter of 35 mm and 6 mm thickness. Instron testing machine with a load of 50 KN and cross-head speed 0.5 mm/min was used for testing the shear bond strength, while surface hardness was tested by Shore A durometer. The morphological features of soft liner samples before and after the addition of CeO2NPs were examined by scanning electron microscopy (SEM). The data were analyzed for normality and homogeneity by Shapiro-Wilk test and for significance by ANOVA and Tukey's multiple comparisons tests using SPSS version 21 software. Results: Soft liner samples demonstrated a significant increase in shear bond strength from 11.6 ± 1.51 MPa for the control group to 16.1 ± 1.37 MPa and 18.9 ± 1.29 MPa for 2%wt. and 3%wt. CeO2NPs treated groups, respectively. The surface hardness value of the samples with the addition of 3%wt. CeO2NPs increased significantly to 61.01 ± 0.98 Shore A in comparison to the control group 59.47 ± 0.97. However, the 2%wt. CeO2NPs-treated group exhibited no significant difference with the rest groups. SEM showed that after CeO2NP incorporation, the nanoparticles were homogenously distributed on the sample surface leading to a decrease in surface porosity. Conclusion: The addition of 2%wt. CeO2NPs improved the shear bond strength of the soft lining material with a non-significant effect on surface hardness. This shows the efficacy of CeO2 in improving some material mechanical properties. [ABSTRACT FROM AUTHOR]

Statement of problem: Soft liners are essential for denture wearers, which aids in the healing of soft tissue injuries caused by rough denture base surfaces. Silicone soft liners, while effective, can accumulate biofilm over time, necessitating enhancement. Purpose: This in vitro study aimed to assess the efficacy of silicone soft liners incorporating varying concentrations of cerium oxide nanoparticles. Materials and methods: A stainless-steel die as per ISO standard 10139-2-2018 (35 × 6 mm), Using G*Power 3.0.10 software, 400 samples were prepared with 95 % confidence interval and 80 % power. Samples were divided into five groups: surface morphology (Group A), surface hardness (Group B), wettability (Group C), cytotoxicity (Group D), and antifungal property (Group E). Each group was subdivided based on cerium oxide nanoparticle concentrations. Samples were stored in artificial saliva until evaluation. Surface morphology was examined via scanning electron microscopy (SEM), surface hardness using Shore A Durometer, wettability by drop shape analysis, cytotoxicity via MTT assay, and antifungal properties using crystal violet staining.Data were assessed for normal distribution using Kolmogorov-Smirnov and Shapiro-Wilk tests. Results: SEM analysis showed optimal nanoparticle dispersion in Group A2(0.25 %) and A3 (0.5 %). Group B2 (0.25 %) exhibited the lowest mean surface hardness, decreasing from day 1 to day 30. Group C3 demonstrated the most hydrophobic surface across days. Group D2 exhibited the least cytotoxicity at all time intervals. Group E4 displayed the highest antifungal activity. Conclusion: Within study limitations, silicone soft liners modified with 0.25 % and 0.5 % cerium oxide nanoparticles exhibited superior properties in surface hardness and cytotoxicity. Optimal surface morphology and wettability were observed with 0.5 % concentration, while antifungal efficacy peaked at 1 %. These findings suggest clinical potential for treating damaged oral tissues. Clinical implications: Soft liners modified with 0.25 % and 0.5 % cerium oxide nanoparticles may benefit patients with oral tissue abuse, offering enhanced therapeutic properties.

Abstract 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.

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. [ABSTRACT FROM AUTHOR]

Background: Soft liners in dentures play a crucial role in enhancing patient comfort and preventing tissue irritation especially for patients with resorbed ridges. However, microbial colonization presents a challenge to their long-term effectiveness, particularly Candida albicans, leading to conditions like denture-induced stomatitis. Objective: To evaluate the antimicrobial efficacy and mechanical properties of heat cured soft liners incorporating plant extracts from Olea europaea and Ficus carcia, individually and synergistically. Patients and Methods: Extracts were obtained through Soxhlet extraction, and their antimicrobial activity against Candida albicans was determined using the broth microdilution method. Soft liner specimens were prepared with varying concentrations of the extracts and subjected to disk diffusion tests, shore A hardness measurements, and peel bond strength tests. Statistical analysis involved the use of one-way ANOVA and Dunnett tests. Results: Results demonstrated significant antimicrobial activity, with the synergistic mixture exhibiting the highest inhibition zone against Candida albicans. Moreover, the addition of such extracts led to increased shore A hardness, with the highest levels recorded for synergistic groups. The extracts also displayed a significant decrease in peel bond strength, indicating potential challenges in adhesive properties. These findings suggest that while individual extracts show promise in antimicrobial efficacy and mechanical reinforcement of soft liners, their combination may lead to compromised adhesive properties. Conclusion: The study contributes valuable insights into the development of antimicrobial soft liners reinforced with Olea europaea and Ficus carcia extracts, advancing dental materials towards improved patient outcomes and enhanced oral health. [ABSTRACT FROM AUTHOR]

Background: A fibrous or flabby ridge is a superficial area of soft, fleshy, mobile soft tissue which affects the alveolar ridge of maxilla or mandible. Conventional impression technique cannot be followed while making impression of flabby ridge area. Conventional acrylic denture cannot be given to individuals having flabby ridge area because hard surface of denture makes uncomfortable to the patients. Case report: A 55 year old male patient had a history of wearing a maxillary complete denture for 5 years. Denture was ill fitting and no retention were present. On intraoral examination, a completely edentulous maxillary arch with inflamed movable flabby tissue was existing in the anterior region. The management started with making diagnostic impression with alginate material and a window has been created in special tray while making a secondary impression. Then border moulding has been done followed by secondary impression. In flabby ridge area it is recorded with the help of light body addition silicone. Then jaw relation and wax try in was done. While processing the denture soft liner was used to cover flabby area which provides the cushioning effect. Conclusion: Implementation of some modifications in current impression techniques and newly introduced materials with improved physical and handling properties, flabby ridges can be treated effectively without any additional visits of patients in clinical practice.

Introduction: This study aimed to assess the effect of the addition of 1%, 1.5%, and 2% by weight silicon dioxide nanoparticles on the surface roughness, surface hardness, tensile strength, and shear bond strength of chairside room temperature silicone-based soft denture liners. Methods: SiO2 nanoparticles (NPs) were added to the soft liner in different concentrations: 0% (control group), 1%, 1.5%, and 2% by weight; surface roughness was measured by profilometer, surface hardness, tensile strength, and shear strength were measured by Instron testing machine. Results: Statistically significant differences were found among study groups regarding surface roughness (p = 0.01), surface hardness (p < 0.0001), tensile bond strength (p = 0.002), and shear bond strength (p < 0.0001). Conclusion: The addition of 1.5% SiO2NPs demonstrated an enhancement in shear stress and tensile strength with a decrease in surface hardness and did not affect surface roughness.

Introduction: This study aimed to assess the effect of the addition of 1%, 1.5%, and 2% by weight silicon dioxide nanoparticles on the surface roughness, surface hardness, tensile strength, and shear bond strength of chairside room temperature silicone-based soft denture liners. Methods: SiO2 nanoparticles (NPs) were added to the soft liner in different concentrations: 0% (control group), 1%, 1.5%, and 2% by weight; surface roughness was measured by profilometer, surface hardness, tensile strength, and shear strength were measured by Instron testing machine. Results: Statistically significant differences were found among study groups regarding surface roughness (p = 0.01), surface hardness (p < 0.0001), tensile bond strength (p = 0.002), and shear bond strength (p < 0.0001). Conclusion: The addition of 1.5% SiO2NPs demonstrated an enhancement in shear stress and tensile strength with a decrease in surface hardness and did not affect surface roughness. [ABSTRACT FROM AUTHOR]

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Background: Soft liners in dentures play a crucial role in enhancing patient comfort and preventing tissue irritation especially for patients with resorbed ridges. However, microbial colonization presents a challenge to their long-term effectiveness, particularly Candida albicans, leading to conditions like denture-induced stomatitis. Objective: To evaluate the antimicrobial efficacy and mechanical properties of heat cured soft liners incorporating plant extracts from Olea europaea and Ficus carcia, individually and synergistically. Patients and Methods: Extracts were obtained through Soxhlet extraction, and their antimicrobial activity against Candida albicans was determined using the broth microdilution method. Soft liner specimens were prepared with varying concentrations of the extracts and subjected to disk diffusion tests, shore A hardness measurements, and peel bond strength tests. Statistical analysis involved the use of one-way ANOVA and Dunnett tests. Results: Results demonstrated significant antimicrobial activity, with the synergistic mixture exhibiting the highest inhibition zone against Candida albicans. Moreover, the addition of such extracts led to increased shore A hardness, with the highest levels recorded for synergistic groups. The extracts also displayed a significant decrease in peel bond strength, indicating potential challenges in adhesive properties. These findings suggest that while individual extracts show promise in antimicrobial efficacy and mechanical reinforcement of soft liners, their combination may lead to compromised adhesive properties. Conclusion: The study contributes valuable insights into the development of antimicrobial soft liners reinforced with Olea europaea and Ficus carcia extracts, advancing dental materials towards improved patient outcomes and enhanced oral health.

Purpose: To investigate retention and stability characteristics of soft-liner and clip attachments used for bar/implant– assisted mandibular overdentures. Materials and Methods: Two implants were placed in an edentulous mandibular model. According to the type of bar, presence of cantilevers, and type of attachments, eight groups were tested: (1) DCC—Dolder bar with cantilevers and three titanium clips, (2) DLC—Dolder bar with cantilevers and resilient liner attachments, (3) DCWC—Dolder bar without cantilevers and one titanium clip, (4) DLWC—Dolder bar without cantilevers and resilient liner attachments, (5) HCC—Hader bar with cantilevers and three plastic clips, (6) HLC—Hader bar with cantilevers and resilient liner attachments, (7) HCWC—Hader bar without cantilevers and one plastic clip, and (8) HLWC—Hader bar without cantilever and resilient liner. Axial (retention) and nonaxial (stability during anterior, posterior, and lateral dislodging) forces were evaluated initially and after 540 times of prosthesis insertions and withdrawals. Results: The highest retention and stability forces were observed with HCC, and the lowest forces were recorded with DLWC. The lowest retention and stability after wear was noted with DCWC and HCWC. For the majority of groups, the highest forces were noted with posterior dislodgment, and the lowest forces were observed with lateral dislodgment. The largest retention loss was recorded with DCC and HCC, and the lowest retention loss was noted with HLWC. DLC and HLC showed retention gain. Conclusion: The Hader bar with clips and cantilever extensions achieved the highest retention and stability forces after wear simulation, while bars without cantilevers and clips showed the lowest forces. For cantilevered Dolder and Hader bars, clip attachments showed increased retention loss, while soft-liner attachments showed retention gain. [ABSTRACT FROM AUTHOR]

Relining is the process of resurfacing the intaglio of a removable dental prosthesis with an entirely fresh base material, generating a precise adaptation to the denture base area. The wetting ability of a denture material gives an indication of the extent to which the lubricating effect of saliva will be enhanced, that promoting retention of denture and patient comfort . The purpose of this research was to evaluate how adding montmorillonite nanoparticles(MMTNPs) would affect the soft lining material's wettability. Materials and Methods: (MMTNPs) with 0.25 and 0.5 wt. of % were incorporated into the heat-cured acrylic-based soft lining. A total of thirty specimens were prepared for wettability test,ten for each concentration (0%,0.25%,0.5% wt.MMTNPs) .Also specimens for atomic force microscope (AFM). The data were analyzed using one-way ANOVA test and the Bonferroni multiple comparison test. Result: The wettability was not significantly decreased as a result. Conclusion: The present study showed that MMTNPs decrease the wettability of soft lining materials. [ABSTRACT FROM AUTHOR]

CONTEXT: Denture relining materials are soft and resilient materials used in the treatment of patients with denture soreness. Studies have concluded that rugged surface of the liners allows the sticking of the Candida albicans and later gives rise to a condition called denture-induced stomatitis. AIMS: The aim of this study is to evaluate and compare the antifungal efficacy and potency of denture soft liners incorporated with powder extract of Lawsonia inermis and Withania somnifera on the growth of C. albicans. MATERIALS AND METHODS: A total of 105 samples were taken in this in vitro study and was divided into three groups: To check for the antifungal activity with 35 samples each. L. inermis and W. somnifera powder extract were incorporated in soft liner at 1%, 3%, 5%, and 7% concentration and the antifungal efficacy against C. albicans was tested by calculating the diameter of inhibition zone for 1, 7, and 14 days. Statistical analysis used: Subgroup analysis was carried out using one-way analysis of variance (ANOVA) test. Pair-wise comparisons were carried out through Tukey's multiple post hoc procedures. RESULTS: When comparison of four subgroups (1%, 3%, 5%, and 7%) was done with the mean zone of antifungal efficacy at 1st day, 7th day, and 14th day time points in both the groups by one-way ANOVA, statistically significant results were obtained with P of 0.0001. CONCLUSIONS: L. inermis and W. somnifera natural herb extracts have shown to have antifungal activity against C. albicans and can be used as an alternative for the synthetic antifungal drugs.

Polymethylmethacrylate (PMMA) is a widely used denture base material in dental practice and the improvement of its properties is important for improving the quality of treatment. The aim of this study is to increase the tensile bond strength between PMMA and soft liner with Thermionic Vacuum Arc. Surface properties were evaluated by Scanning Electron Microscope, Energy-Dispersive X-ray Analysis, and Atomic Force Microscope after the tensile bond strength test. As a result, the ZnO coating with TVA positively affects the PMMA surface properties compared to Ag and SnO2 groups and promising for clinical use. [ABSTRACT FROM AUTHOR]

This rerandomized clinical trial evaluated the influence of soft liners (SL) on biting force, pain perception, and the oral health-related quality of life (OHRQoL) of complete denture wearers. Twenty-eight completely edentulous patients complaining of ill-fitting lower complete dentures were selected to participate in the study from the Dental Hospital, College of Dentistry, Taibah University. All patients received new complete maxillary and mandibular dentures; then they were randomly divided into two groups (14 patients in each group): the acrylic-based SL group, in which the mandibular denture was lined with an acrylic-based soft liner, and the silicone-based SL group, in which the mandibular denture was lined with a silicone-based soft liner. OHRQoL and maximum bite force (MBF) were assessed in this study before denture relining (baseline), then at one month and three months after relining. The finding showed that both treatment modalities significantly improved the OHRQoL of included patients at one-month and three-month periods compared to baseline records (i.e., dentures before relining) with a statistically significant difference (p < 0.05). However, there is no statistical difference between groups at the baseline, one-, and three-month follow-up periods. Regarding maximum biting force, when acrylic-based SL is compared to silicone-based SL, there is no statistical difference between groups at baseline (75 ± 31 and 83 ± 32 N) and one-month follow-up periods (145 ± 53 and 156 ± 49 N); however, after three months of function, the silicone-based group recorded 166 ± 57 N statistically significant high biting force compared to the acrylic-based group that recorded 116 ± 47 N (p < 0.05). Permanent soft denture liners positively affect maximum biting force, pain perception, and OHRQoL more than conventional dentures. After three months, silicone-based SL outperformed acrylic-based soft liners in maximum biting force, which may indicate better long-term results. [ABSTRACT FROM AUTHOR]

CONTEXT: Denture relining materials are soft and resilient materials used in the treatment of patients with denture soreness. Studies have concluded that rugged surface of the liners allows the sticking of the Candida albicans and later gives rise to a condition called denture-induced stomatitis. AIMS: The aim of this study is to evaluate and compare the antifungal efficacy and potency of denture soft liners incorporated with powder extract of Lawsonia inermis and Withania somnifera on the growth of C. albicans. MATERIALS AND METHODS: A total of 105 samples were taken in this in vitro study and was divided into three groups: To check for the antifungal activity with 35 samples each. L. inermis and W. somnifera powder extract were incorporated in soft liner at 1%, 3%, 5%, and 7% concentration and the antifungal efficacy against C. albicans was tested by calculating the diameter of inhibition zone for 1, 7, and 14 days. STATISTICAL ANALYSIS USED: Subgroup analysis was carried out using one-way analysis of variance (ANOVA) test. Pair-wise comparisons were carried out through Tukey's multiple post hoc procedures. RESULTS: When comparison of four subgroups (1%, 3%, 5%, and 7%) was done with the mean zone of antifungal efficacy at 1st day, 7th day, and 14th day time points in both the groups by one-way ANOVA, statistically significant results were obtained with P of 0.0001. CONCLUSIONS: L. inermis and W. somnifera natural herb extracts have shown to have antifungal activity against C. albicans and can be used as an alternative for the synthetic antifungal drugs. [ABSTRACT FROM AUTHOR]

Purpose: This study aimed to investigate the tensile bond strength between soft relining materials and different denture base materials., Materials and Methods: The study was conducted in accordance with ISO 23401:2023. A total of 288 rectangular specimens (10L × 10H × 20W mm) were fabricated from various denture base materials, including a heat-compression polymethylmethacrylate (PMMA), two types of milled PMAA, and three types of 3D-printed resins, with bonding using two chairside soft reline materials (Coe-Soft and Lynal). Specimens were placed in distilled water for 24 h before applying tensile force at a 5 mm/min crosshead speed. The tensile bond strength values (MPa) were calculated at maximum tensile force (N) before failure. Two-way ANOVA and post hoc multiple comparison tests were used to assess the effect of denture base and soft reline materials on the tensile bond strength (α = 0.05)., Results: A significant difference in the tensile bond strength was found among the different types of denture base materials (p < 0.001), regardless of relining material type. Lynal-relined milled IvoBase demonstrated the highest tensile bond strength (0.5 ± 0.06 MPa), followed by Lynal-relined milled Lucitone (0.44 ± 0.03 MPa), both of which are clinically acceptable as they are equal or greater 0.44 MPa. The lowest tensile bond strength was detected in Lynal-relined 3D printed FotoDent (0.09 ± 0.02 MPa). Lynal exhibited significantly higher tensile bond strength (p < 0.05) than Coe-Soft soft reline material when bonded to PMMA bases; however, there was no significant difference between Lynal and Coe-Soft when bonded to 3D-printed base materials (p > 0.05)., Conclusions: The tensile bond strength between soft relining materials and denture bases is material-dependent, influenced by both the type of denture base material and the type of soft relining material used., (© 2024 by the American College of Prosthodontists.)

Introduction The cushion effect of soft liners serves to distribute the mastication forces and stresses more evenly, along with absorbing energy. Instead, soft liners can act as a nidus for microbial growth, especially Candida species. An accumulation of these fungi is a problem encountered during the clinical use of them, especially in immunocompromised individuals. This study aimed to evaluate and compare the antifungal activity of soft liners when combined with posaconazole and voriconazole. Methods For this study, one soft liner and two antifungal drugs were used. Before testing, drugs were incorporated in a soft liner, and discs were made that were allowed to be immersed in distilled water. Three groups of five samples each were used to categorize the specimens: groups I, II, and III were GC soft liner, GC soft liner + posaconazole, and GC soft liner + voriconazole, respectively. These samples were assessed for antifungal activity on the 1st, 10th, and 20th day. For antifungal activity, the zone of growth inhibition was measured. Results A statistically significant difference in zone of growth inhibition across three groups was observed. Group II had the highest zone of inhibition, followed by group III and group I, which had the least. In intragroup comparisons over different time intervals, statistically significant variations were observed; day 20 had the highest zone of inhibition, followed by day 10 and day 1. Conclusion Significant changes were seen in the antifungal properties of posaconazole and voriconazole with the soft liner. Posaconazole in soft liners showed a significantly higher zone of growth inhibition than the other two groups., Competing Interests: Human subjects: All authors have confirmed that this study did not involve human participants or tissue. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Sharma et al.)

The concept of conditioning edentulous ridge mucosa has gained momentum over the last several years. Frequent relining of the complete denture may be required because of soft tissue changes arising from underlining bone resorption. Patients with the maxillary flabby ridge had difficulty in tolerating hard denture, inadequate retention, and stability of a complete denture are often encountered, so the denture can be made more comfortable using soft liner. Hardening of the soft liner with time, harboring of bacteria, and debonding from denture base is a major drawback of soft lining materials. Introduction of liquid-supported dentures, to be an alternative to conventional complete denture prosthesis in cases suffered from inflamed tissues and severely resorbed edentulous ridges. A liquid supported denture provides an alternate treatment option due to its soft and flexible intaglio surface allows better distribution of masticatory load stress since in such cases. Liquid supported acrylic complete denture can be useful as a permanent solution in edentulous patients with the atrophied ridge. Liquid supported denture could be a useful alternative for soft relining materials.

Microbial growth and colonization are one of the disadvantages after the long-term use of denture soft liners. This study was aimed to evaluate the effect of the addition of magnesium oxide nanoparticles (MgONPs) on the antimicrobial activity of a denture soft liner. A total of 84 samples were prepared from a soft denture liner and divided into two groups, control group and test group to which 3% by weight of MgONPs were added, antimicrobial tests for Candida albicans, Staphylococcus aureus, and a mixture of the biofilm of both microorganisms were done, cell density count and adherence assay test was recorded before and after 6 months storage in distilled water. The results showed that the modified group performed a better antimicrobial activity compared to the control group, the addition of 3% of the nanofiller showed a significant reduction in the mean value of growth of both C. albicans, S. aureus, and the biofilm mixture (P < 0.05) before and after the storage period. In conclusion, the addition of 3% by weight of MgONPs to the denture soft liner significantly suppressed the growth of C. albicans, S. aureus up to 6 months.

Today, soft liners are being widely used in dental practices by their application to the inner surfaces of the denture with hopes to evenly distribute any potential uneven forces, and to provide a cushion effect to the oral mucosa of the patient mouth. The aim of this study is to investigate the influence of (a) polymethylmethacrylate (PMMA) denture base material curing technique, (b) Molloplast B soft liner curing technique, and (c) PMMA surface treatment, on the “shear bond strength” (SBS) between the Molloplast B liner and PMMA. A total of 80 samples were used in this study to evaluate the SBS performance of microwave (Nature-Cryl, Acron Gc, Japan) and conventional water bath (Ivoclar triplex, Liechtenstein) curing techniques of PMMA, and to evaluate the curing technique of soft liner material Molloplast B (DETAX,GERMANY). Surface treatment of PMMA was performed for half of the samples using neodymium:yttrium aluminum-garnet Nd:YAG laser, and the other half of the samples were surface-treated using AL2O3 sandblasting method. The results showed that the highest mean value in conventional water bath-cured soft liner was 26.69 MPa, whereas the lowest mean value for microwave-cured soft liner was 15.22 MPa. No significant difference was observed between the SBS performance regarding the PMMA surface treatment and curing techniques. Conventional water bath curing technique for soft liner treatment improved the SBS performance. Regarding the PMMA curing technique, the conventional water bath achieved higher SBS, yet the difference was not statistically significant. Finally, surface treatment using laser improved the SBS compared to sandblasted method, but the improvement here was also statistically insignificant.

Amaç: Çalışmanın amacı, polidimetilsiloksan protez astarının farklı boyutlardaki alüminyum oksit parçacıkları ile kumlanmış olan protez kaide maddesine gerilme bağlanma mukavemetini araştırmaktır. Gereç Yöntemler: Kırk adet iki parçadan dikdörtgen prizma şeklinde ısı ile polimerize edilmiş akrilik örnekler bağlantı dayanımıiçin değerlendirilecektir. Örnekler uygulanan yüzey işlemine göre 4 test grubuna ayrılmıştır. Grup I: Yüzey işlemi uygulanmayan (kontrol grubu) Grup II: Kumlama ile birlikte tribokimyasal silika kaplama Grup III: 50 μm alüminyum oksit partikülleri ile kumlama Grup IV: 110 μm alüminyum oksit partikülleri ile kumlama. Bütün örnekler yumuşak astar ile bağlantı sağlandıktan sonra 5000 devir termal siklusa tabi tutulmuştur. Bağlantı değeri, evrensel test cihazı kullanılarak çekme test ile belirlenmiştir. Verilerin normalliği Shapiro-Wilk testi ile test edildi. Tüm veriler tek yönlü ANOVA kullanılarak analiz edildi ve ortalama değerleri Tukey’in HSD testi ile karşılaştırıldı. (p

Introduction: Silver nanoparticles (SNPs) have recently been suggested to increase the antimicrobial properties of soft liner materials. However, their safety remains a matter of debate. This study aimed to evaluate the cytotoxicity of Mucopren® soft silicone liner material (Mucopren; Kettenbach, Germany) incorporated in SNPs. Methods: The SNPs with over 98% purity were added to Mucopren in 0.5, 1, 2, and 3 weight percentage (wt%) concentrations and manually homogenized. The mixture of the pieces of Mucopren plus SNPs and SNPs alone were placed in 96-well plates containing Dulbecco's Modified Eagle Medium culture, FBS, and antibiotics with L929 fibroblasts. Cell viability and biocompatibility were determined after 1, 2, and 3 days of incubation using the methylthiazol tetrazolium assay. Optical density was read by an ELISA reader at 570 nm and compared to those of positive and negative controls. Results: Among Mucopren mixed with different SNPs concentration, the cell toxicity had no significant difference in the same days, and cell toxicity decreased over time (P=0.016). The SNPs alone were less cytotoxic than Mucopren incorporated SNP samples (P>0.05). Conclusion: Within the limitations of this study, the addition of 0.5, 1, 2, and 3wt% concentrations of SNPs to Mucopren did not cause a significant change in its cell toxicity in an in vitro condition

Statement of Problem: Soft liners are essential for denture wearers, which aids in the healing of soft tissue injuries caused by rough denture base surfaces. Silicone soft liners, while effective, can accumulate biofilm over time, necessitating enhancement., Purpose: This in vitro study aimed to assess the efficacy of silicone soft liners incorporating varying concentrations of cerium oxide nanoparticles., Materials and Methods: A stainless-steel die as per ISO standard 10139-2-2018 (35 × 6 mm), Using G*Power 3.0.10 software, 400 samples were prepared with 95 % confidence interval and 80 % power. Samples were divided into five groups: surface morphology (Group A), surface hardness (Group B), wettability (Group C), cytotoxicity (Group D), and antifungal property (Group E). Each group was subdivided based on cerium oxide nanoparticle concentrations. Samples were stored in artificial saliva until evaluation. Surface morphology was examined via scanning electron microscopy (SEM), surface hardness using Shore A Durometer, wettability by drop shape analysis, cytotoxicity via MTT assay, and antifungal properties using crystal violet staining.Data were assessed for normal distribution using Kolmogorov-Smirnov and Shapiro-Wilk tests., Results: SEM analysis showed optimal nanoparticle dispersion in Group A2(0.25 %) and A3 (0.5 %). Group B2 (0.25 %) exhibited the lowest mean surface hardness, decreasing from day 1 to day 30. Group C3 demonstrated the most hydrophobic surface across days. Group D2 exhibited the least cytotoxicity at all time intervals. Group E4 displayed the highest antifungal activity., Conclusion: Within study limitations, silicone soft liners modified with 0.25 % and 0.5 % cerium oxide nanoparticles exhibited superior properties in surface hardness and cytotoxicity. Optimal surface morphology and wettability were observed with 0.5 % concentration, while antifungal efficacy peaked at 1 %. These findings suggest clinical potential for treating damaged oral tissues., Clinical Implications: Soft liners modified with 0.25 % and 0.5 % cerium oxide nanoparticles may benefit patients with oral tissue abuse, offering enhanced therapeutic properties., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

The purpose of this study was to evaluate anti-candidal activity, gelation time, and surface hardness of a short-term soft lining material incorporated with varying concentrations of Piper betle extract (0.25 to 20% w/w). Agar-diffusion assay was conducted to evaluate an inhibitory effect against Candida albicans. The gelation time was assessed and surface hardness was measured at 2 h and 7 days by Shore AO durometer. A soft liner containing at least 5% w/w of P. betle extract was observed the inhibitory effect against C. albicans. An increasing of P. betle concentrations provided larger inhibition zone. Incorporating 5% w/w of P. betle extract into the soft liner did not significantly alter its gelation time and surface hardness (ANOVA; p>0.05). The optimum composition at 5% w/w of P. betle extract can be used as an additive in the soft liner to provide the anti-candidal activity without significantly affect these two main properties. [ABSTRACT FROM AUTHOR]

Background and objective: This study was aimed to determine the effect of addition of 3% of Magnesium Oxide Nanoparticles (MgONPs) on the surface hardness (SH) and tensile bond strength (TBS) of asilicone based denture liner at various time intervals. Method: The SH and TBS of a silicone denture liner were studied after addition of 3% by weight of MgONPs. A total of 140 samples were constructed. The samples were divided into two main groups, control group and test group to which 3% of MgONPs were added.Results: The SH of all the samples for both groups was significantly higher after a period of 6 months. For TBS the pattern was reversed in which there was a decrease in the mean of TBS for both control and test groups significantly. Conclusion: The addition of 3%(MgONPs) to Silicone denture liner causes a non-significant effect in the SH but significantly improves TBS. [ABSTRACT FROM AUTHOR]

Denture stomatitis is one of the serious problems that are related to the continuous use of soft lining material due to the accumulation of microorganisms. It is caused mainly by fungal growth, especially of Candida albicans. It, therefore, becomes necessary to examine the effectiveness of incorporating an antifungal drug into the soft lining material.This study was conducted to investigate the efficacy of adding the kappa-carrageenan powder to heat-cured, acrylic-based soft lining material against Candida albicans adherence.A pilot study was performed to decide the best concentration of kappa-carrageenan to be used with the heat-cured, acrylic-based soft liner. Five percentages by weight of kappa-carrageenan powder (0.5, 1, 1.5, 2, and 2.5wt.%) were evaluated and compared with the control group (0wt.%). The Candida albicans adherence test was performed to assess the efficacy of kappa-carrageenan powder in preventing the adherence of Candida albicans. Results showed the 1.5wt.% and 2wt.% groups as having the best effect.The main study included preparing thirty samples and dividing them into three groups based on the percentage of powder of kappa-carrageenan added to the heat-cured acrylic-based soft lining material (control: 0wt.%; experimental: 1.5wt.% and 2wt.%). The purpose of performing Candida albicans adherence test was to evaluate the antifungal efficacy of kappa-carrageenan powder addition, and all the resulted data were analysed using “one-way analysis of variance (ANOVA) and Dunnet T3 post-hoc test at a significance level of p<0.05”.The results of Candida albicans adherence test revealed a highly significant decrease in the values of the adhered Candida albicans cells after incorporation of 1.5wt.% and 2wt.% of kappa-carrageenan powder when compared to the control group (p<0.01).The result of this study suggests that the addition of kappa-carrageenan powder is an effective drug against Candida albicans adherence on the surface of the heat-cured acrylic-based soft lining material, and the addition of 2wt.% is more effective than 1.5wt.%. [ABSTRACT FROM AUTHOR]

Introduction: Silver nanoparticles (SNPs) have recently been suggested to increase the antimicrobial properties of soft liner materials. However, their safety remains a matter of debate. This study aimed to evaluate the cytotoxicity of Mucopren® soft silicone liner material (Mucopren; Kettenbach, Germany) incorporated in SNPs. Methods: The SNPs with over 98% purity were added to Mucopren in 0.5, 1, 2, and 3 weight percentage (wt%) concentrations and manually homogenized. The mixture of the pieces of Mucopren plus SNPs and SNPs alone were placed in 96-well plates containing Dulbecco's Modified Eagle Medium culture, FBS, and antibiotics with L929 fibroblasts. Cell viability and biocompatibility were determined after 1, 2, and 3 days of incubation using the methylthiazol tetrazolium assay. Optical density was read by an ELISA reader at 570 nm and compared to those of positive and negative controls. Results: Among Mucopren mixed with different SNPs concentration, the cell toxicity had no significant difference in the same days, and cell toxicity decreased over time (P=0.016). The SNPs alone were less cytotoxic than Mucopren incorporated SNP samples (P>0.05). Conclusion: Within the limitations of this study, the addition of 0.5, 1, 2, and 3wt% concentrations of SNPs to Mucopren did not cause a significant change in its cell toxicity in an in vitro condition. [ABSTRACT FROM AUTHOR]

To compare the masticatory performance in complete denture patients before and after application of soft liner and to assess the effect of aging of soft liner on masticatory performance at different intervals of time. A total of 30 complete denture wearers between age of 64 and 80 years, were selected from both the sex (20 men, 10 women). This study evaluated the effect of before and after application of chair-side soft liner on masticatory performance of complete denture wearers by using raw carrots and roasted peanut as the test food. This study further evaluated the cushioning effect of chair-side soft liner material at the interval period of 1week, 4 weeks, 8 weeks, 12 weeks and 16 weeks. There were significant differences in masticatory performance without soft liner as compared to with soft liner at different intervals of time. The performance was found to be significantly higher for raw carrot as compared to roasted peanut (p < 0.001). For both the materials peak performance was recorded at 4th week. The use of soft liner helps in increasing the masticatory performance among complete denture wearers. [ABSTRACT FROM AUTHOR]

Background The main disadvantages the soft liners, is the absence of a durable bond to the denture base, this caused adhesion failure between them, creating an environment for colonization bacterial and compromise the durability of the Soft denture liners. The objective of this study was to evaluate the effect of silver-zinc zeolite incorporated into heat cure acrylic soft liner on shear bond strength. Materials and methods Thirty specimens of heat cure soft liner were prepared and divided into three groups after incorporation of Ag-Zn as follows; Control Group: which have 10 specimens without Ag-Zn zeolite. Experimental Group: which have ten specimens with 0.5% by weight of Ag-Zn; Experimental Group: which have 10 specimens with 0.75% weight of Ag-Zn zeolite plastic pattern sample which used for acrylic block fabrication were (75 mm length × 25 mm width × 5 mm depth. The handle of acrylic block thickness is 13mm. Shear bond strength of all specimens was evaluated. Results The LSD test showed The experimental groups of 0.75% and 0.5% significant difference compared with the control group (p<0.05). While the comparison between experimental groups (0.75% and 0.5%) had recorded non-significant difference at p >0.05. Conclusions incorporation from (0.5% and 0.75%) of Ag-Zn Zeolite into heat soft liner had a significant effect on shear bond strength. [ABSTRACT FROM AUTHOR]

Fingers as organs of manipulation have an important role in function and aesthetics. Injuries to the fingers are common in accidents at home, work, and play or due to congenital and developmental defect. Irrespective of the aetiology, the loss of a finger has a considerable functional and psychological impact on an individual. In order to alleviate these problems, partial or complete finger prosthesis can be fabricated. This clinical report presents a method to fabricate finger prosthesis using digital photograph, poly methylemethacrylate acrylic and soft liner for a patient who has a partial finger loss caused due to trauma. [ABSTRACT FROM AUTHOR]

This paper describes the design and fabrication of a soft liner-retained, implant-supported overdenture used in 10 patients over a period of 1 to 6 years. A final complete denture impression is made of the dental arch, including implant abutments extending 5 mm above the gingival tissue. The master cast is fabricated with actual abutments placed in the impression. After the final wax try-in, the denture is flasked in the usual manner with the metal abutments in place. Before packing with acrylic resin, plastic tubing 1 to 2 mm thick is placed around each abutment. The denture is trial packed and allowed to bench cure over night. The plastic tubing is then removed and a soft denture lining material is placed in these areas only. The flask is closed and cured according to the manufacturer's recommendation. The denture is delivered as a conventional overdenture. [ABSTRACT FROM AUTHOR]

A patient with a failed implant-supported prosthesis was treated with an immediate interim overdenture. After insertion of a bar modified from the prosthesis substructure, the patient was restored with an implant-supported overdenture. A bar soft liner retention system was used to aid retention and stability of the overdenture. [ABSTRACT FROM AUTHOR]

Purpose: Soft liners act as a cushion between the denture base and the residual ridge. Hence, it is important to study their effect on resorption of mandibular denture bearing area. Therefore, the purpose of this study was to evaluate the influence of soft denture liner on mandibular ridge resorption after 1 year in completely denture wearers. Materials and Methods: Twenty-eight completely edentulous patients having age between 45 and 60 years with well-formed ridges in class I jaw relations were selected as per the inclusion and exclusion criterion. Randomization chart was used to enroll participants in experimental and control groups who were given mandibular dentures with and without soft denture liner, respectively. Vertical measurements were made on orthopantomograph and analyzed using Adobe Photoshop 7.0 software at five points, i.e., one at central incisor and two points at right and left first premolars and two in each first molar region. Results: On application of repeated measures analysis of variance, both groups showed a significant change in bone height after denture delivery (P < 0.05). Intergroup comparison (Wilcoxon rank sum test) of bone height in different regions at various time intervals showed statistically significant difference in bone levels (P < 0.05) from baseline to 6 months and baseline to 12months (P < 0.01), while the difference was statistically not significant during 6 and 12 months’ period. Conclusion: The use of soft denture liner significantly reduces the residual ridge resorption in complete denture wearers as compared to conventional denture wearers (without denture liner) over a period of 1 year.

Abstract Background/purpose Denture soft liners, especially used for elders who have poor disinfection habits, provide a favourable environment for accumulation and colonization of microorganisms. This in vitro study is aimed to investigate the effectiveness of natural carvacrol incorporation into soft lining material on the inhibition of oral pathogens. Materials and methods Antimicrobial susceptibility of carvacrol was primarily determined by disc diffusion method. Soft lining material was prepared as recommended by the manufacturer and 10 μL carvacrol was added aseptically to the soft liner discs. Inhibition zones for the control discs without carvacrol (C) and carvacrol-incorporated discs (CL) were determined by disc diffusion method. The biofilm inhibition percentages of carvacrol on soft liner was determined by MTT assay and also observed by Scanning Electron Microscopy (SEM). Results Carvacrol displayed great antimicrobial activity for yeast, Gram-negative and Gram-positive strains. The highest inhibition zone of carvacrol (41.33 ± 1.53 mm) was measured for Bacillus subtilis strain which is followed by Candida albicans and Streptococcus sanguis (34.00 ± 1.73 mm and 32.33 ± 0.58 mm, respectively). The inhibition zones were also similar for soft liner discs with carvacrol, with the highest inhibition zones against B. subtilis , Streptococcus mutans and C. albicans (43.67 ± 0.58 mm, 40.33 ± 0.58 mm and 38.33 ± 1.15 mm, respectively). Incorporation of carvacrol into the soft liner decreased (98.03 ± 0.2%) of the biofilm formation for C. albicans. Conclusion Carvacrol-incorporation obviously decreased the colonization and plaque formation of oral pathogens, especially C. albicans accumulation. Carvacrol may be useful as a promising agent for antibacterial and antifungal management for denture soft lining materials. [ABSTRACT FROM AUTHOR]

Tissue conditioners can be used to condition abused tissues, record functional impressions, make temporary relining for surgical splints and obturators, and for other clinical applications, mainly because of their specific viscoelasticity. Their function in complete denture fabrication is debatable but their use as a functional impression material has been proved. The present article describes a technique for using tissue conditioners as functional impression materials. Correct method of usage, manipulation, specific properties as impression materials and precautions in different situations for obtaining accurate impressions has been highlightened.

Aim: To evaluate dose calculation accuracy of various algorithms in lung equivalent inhomogeneity comprising tumor within it and comparison with Gafchromic film data.Materials and Methods: Gafchromic film measured central axis absorbed dose in lung insert (-700 Hounsfield unit [HU]), in racemosa wood cylindrical inhomogeneity (-725 HU) and at three surfaces of tumor (-20 HU) created in cylindrical inhomogeneity, put in the cavity of computerized imaging reference systems (CIRS) thorax phantom were compared with convolution (CON), superposition (SP), fast SP (FSP), and X-ray voxel Monte Carlo (XVMC) algorithms calculated dose using 6 MV beams of field size 2 cm × 2 cm, 3 cm × 3 cm, 4 cm × 4 cm, 5 cm × 5 cm, and 8 cm × 8 cm.Results: XVMC was in good agreement with film measured results for all selected field sizes except 3 cm × 3 cm. SP under estimated by 5.7% at the center of the lung insert while deviation up to 6% was found at the cent of wood inhomogeneity in 2 cm × 2 cm. Except CON, increase in dose from proximal to the central surface of the tumor and then dose falloff from central to the distal surface for field size 2 cm × 2 cm to 4 cm × 4 cm was recorded. The change in film measured percentage depth dose from 2 cm × 2 cm to 3 cm × 3 cm field sizes was found -8% however for consecutive field size(s) larger than 3 cm × 3 cm this difference was less. CON and FSP produced overestimated results.Conclusion: Out of four algorithms, XVMC found consistent with measured data. The electronic disequilibrium within and at the interface of inhomogeneity make the accurate dose predictions difficult. These limitations results in deviations from the expected results of the treatments. [ABSTRACT FROM AUTHOR]

Long-term clinical and prosthetic outcomes of soft liner attachments for bar/implant overdentures were not sufficiently investigated. The aim of this trial was to evaluate clinical and prosthetic outcomes of resilient liner and clip attachments for bar/implant-retained mandibular overdenture after 7 years. Thirty edentulous male participants received two implants in the canine areas of the mandible. Three months later, implants were splinted with a resilient bar. Mandibular overdentures were connected to the bars with either clip ( CR group, n = 15) or resilient liner ( RR group, n = 15) attachments. Plaque index ( PI), gingival index ( GI), probing depth ( PD), vertical bone loss ( VBL), horizontal bone loss ( HBLO) and prosthetic complications ( PCs) were evaluated at denture delivery (T0), 6 (T6m), 12 (T1), 24 (T2), 36 (T3), 48 (T4), 60 (T5), 72 (T6) and 84 (T7) months after insertion. PI and GI increased significantly with time for CR and decreased significantly for RR ( P < 0·001). PD increased at T1 ( CR) and T6 m ( RR) and then decreased thereafter ( P < 0·05). VBL increased significantly with time in both groups ( P < 0·005). HBLO increased at T2 ( CR) and T1 ( RR) and then decreased thereafter. CR recorded significant higher PI, GI, PD, VBLO and HBLO compared to RR at all observation times ( P < 0·042). The survival rates were 96·6% and 100% for CR and RR after 7 years. The most common PCs for CR and RR were clip wears and separation of the resilient liner from the denture base, respectively. Within the limitations of this study, resilient liner attachments are recommended for bar/implant-retained mandibular overdentures than clip attachments in terms of peri-implant tissue health and prosthetic complications after 7 years. [ABSTRACT FROM AUTHOR]

Soft polymers used under tissue-supported prostheses have limited service life because of surface degradation. Purpose: This paper evaluates the changes in surface properties and softness of soft relining materials after cyclic loading in water. Materials and Methods: 3 polysiloxane (Silagum AM Comfort, Molloplast B, Mollosil Plus) and 2 acrylic-based (Vertex Soft, Astron LC Soft) proprietary soft relining materials and a vinyl polysiloxane (Imprint 2 Garant) as the reference impression material evaluated. A stainless steel block for detail reproduction was used on the basis of the apparatus recommended by the ISO 4823:1992 test method for preparing a standardized surface. A control group from each material was only subjected to water immersion. Non-destructive cyclic loading was carried out with a strain of 16.6 % and a frequency of 1.6 Hz 200,000 times in distilled water at 37 °C. The specimens were then duplicated and compared with the controls using roughness measurements, detail reproduction and Scanning Electron Microscope. Shore A hardness values before and after cycling were also measured. Results: After degradation in the form of mechanical cycling in water, loss of substance and loss of surface detail was observed. Surface properties and Shore A hardness values of acrylic-based soft liners changed significantly ( p < 0.05). Conclusions: The chemical composition of the soft relining materials seemed to affect their potential of preserving the surface texture and softness after mechanical cycling. Mechanical cycling influences the surface degradation process leading to changes of the surface texture. Polysiloxane-based materials preserved their softness, surface texture and surface smoothness better under cyclic loading compared to acrylic resin -based plasticized materials. [ABSTRACT FROM AUTHOR]