ORIGINAL RESEARCH An In-Vitro Assessment of Surface Roughness, Tensile Bond Strength and Antifungal Activity of Grape Seed Extract- modifed Soft Liner Neven S Aref A BSTRACT Aim: This study was conducted to evaluate the grape seed extract (GSE)-modifed soft liner regarding surface roughness, tensile bond strength to the denture base material, and the antifungal activity. Materials and methods: The GSE powder was blended with the soft liner powder in ratios of 5 and 10% w/w, and three groups were employed: I, control; II, 5% w/w GSE-modifed soft liner; III, 10% w/w GSE-modifed soft liner. Evaluation parameters included surface roughness, tensile bond strength to the denture base material, and the antifungal activity. Changes in surface topography were evaluated by scanning electron microscopy. The statistical analysis was performed using the one-way ANOVA followed by the Tukey’s test (α = 0.05). Results: The 5% w/w GSE-modifed soft liner showed a signifcant increase in surface roughness, while both ratios (5 and 10% w/w) of the modifed-soft liner exhibited signifcant increase in tensile bond strength and antifungal activity (p < 0.05). Conclusion: The GSE of 10% w/w considerably enhanced the antifungal activity and tensile bond strength of the modifed soft liner to the denture base material without compromising its surface roughness. Clinical signifcance: The 10% w/w GSE-modifed soft liner may be a promising formulation with antifungal activity. It could inhibit fungal adherence and development of fungi-induced lesions or exacerbation of existing ones. Keywords: Antifungal activity, Grape seed extract, Soft liner, Surface roughness, Tensile bond strength. The Journal of Contemporary Dental Practice (2020): 10.5005/jp-journals-10024-2810 I NTRODUCTION Complete dentures are frequently constructed from rigid acrylic resins that have many favorable properties, including satisfactory physicomechanical properties capable of withstanding biting forces, as a consequence resist fracture and distortion. 1 Nevertheless, this rigidity may cause patient discomfort, mucosal lesions, or exacerbation of existing lesions. 2 Several causes have been correlated to the denture-induced stomatitis such as allergy to the denture base material, poor oral hygiene, fungal infection, trauma from occlusion, hematological disorders, and occlusion trauma. 3 Accordingly, resilient denture liners have been developed for restoration of inflamed supporting tissues, severe bone resorption, and providing more stability to the prosthesis. 4 These materials are designed to absorb part of the masticatory forces during function reducing energy transmitted to the underlying tissues. 5 Despite these advantages, soft liners still have certain drawbacks like hardening due to loss of plasticizer, colonization of microorganisms, particularly Candida albicans, porosity, poor tear strength, and the failure of bond to denture base. 6 The composition, surface roughness, and micromorphology of tissue-relining materials are important factors to be kept in mind, considering that roughness provides more retention of residues, microorganisms, and pigments that may compromise the longevity of the material. 7 Preceding studies 8,9 reported that incorporation of antifungal agents into soft liners to compensate for these problems could afect their structural properties and bond strength. Maintaining a good bond of the liner to the denture base ensures the longevity of the liner in service. 10 Natural products are important sources to be considered for getting chemically standardized extracts for medical applications. 11 Recently, an interest on the grape seed extract (GSE) (Vitis vinifera) as an antimicrobial and antifungal alternative is noticed. This extract is rich in naturally occurring polyphenolic compounds and consists of free monomeric favanols, i.e., the proanthocyanidins (PAs). 12 Proanthocyanidins are a combination of monomers, oligomers, and polymers of favan-3-ols (known as catechins). They are extensively used as natural antioxidants and free radical scavengers and have been verifed to be used safely in many clinical situations. 13 It has been reported that PAs increased collagen synthesis and hastened Dental Biomaterials Department, Faculty of Dentistry, Mansoura University, Mansoura, Egypt; Basic Oral and Medical Sciences Department, College of Dentistry, Qassim University, Buraydah, Kingdom of Saudi Arabia Corresponding Author: Neven S Aref, Dental Biomaterials Department, Faculty of Dentistry, Mansoura University, Mansoura, Egypt; Basic Oral and Medical Sciences Department, College of Dentistry, Qassim University, Buraydah, Kingdom of Saudi Arabia, Phone: +20 1003978955, e-mail: ffaref@gmail.com How to cite this article: Aref NS. An In-Vitro Assessment of Surface Roughness, Tensile Bond Strength and Antifungal Activity of Grape Seed Extract-modifed Soft Liner. J Contemp Dent Pract 2020;21(4):353–358. Source of support: This study is not fnancially supported by anybody or institution. It is self-funded by the author and it was performed as a part of the author employment. The author does not have any fnancial interest in the companies whose materials are included in this article. The employers are Mansoura University and Qassim University Confict of interest: None © The Author(s). 2020 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons. org/licenses/by-nc/4.0/), which permits unrestricted use, distribution, and non-commercial reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.