The Effect of Ultraviolet Treatment on TiO2 Nanotubes: A Study of Surface Characteristics, Bacterial Adhesion, and Gingival Fibroblast Response

Titanium dioxide (TiO2) nanotubes are emerging as a provocative target for oral implant research. The aim of this study was to evaluate the effect of UV on the wettability behavior, bacterial colonization, and fibroblast proliferation rate of TiO2 nanotube surfaces prepared using different anodization voltages and aimed for use as implant abutment materials. Four different experimental materials were prepared: (1) TiO2 nanotube 10 V; (2) TiO2 nanotube 15 V; (3) TiO2 nanotube 20 V; and (4) commercial pure titanium as a control group. TiO2 nanotube arrays were prepared in an aqueous electrolyte solution of hydrofluoric acid (HF, 0.5 vol.%). Different anodization voltages were used to modify the morphology of the TiO2 nanotubes. Equilibrium contact angles were measured using the sessile drop method with a contact angle meter. The investigated surfaces (n = 3) were incubated at 37 °C in a suspension of Streptococcus mutans (S. mutans) for 30 min for bacterial adhesion and 3 days for biofilm formation. Human gingival fibroblasts were plated and cultured on the experimental substrates for up to 7 days and the cell proliferation rate was assessed using the AlamarBlue assayTM (BioSource International, Camarillo, CA, USA). The data were analyzed using one-way ANOVA followed by Tukey’s post-hoc test. Water contact angle measurements on the TiO2 after UV treatment showed an overall hydrophilic behavior regardless of the anodization voltage. The ranking of the UV-treated surfaces of experimental groups from lowest to highest for bacterial adhesion was: TiO2 nanotube 20 V < Ti and TiO2 nanotube 15 V < TiO2 nanotube 10 V (p < 0.05), and for bacterial biofilm formation was: TiO2 nanotube 20 V-TiO2 nanotube 10 V < Ti-TiO2 nanotube 15 V (p < 0.05). Fibroblast cell proliferation was lower on TiO2 nanotube surfaces throughout the incubation period and UV light treatment showed no enhancement in cellular response. UV treatment enhances the wettability behavior of TiO2 nanotube surfaces and could result in lower bacterial adhesion and biofilm formation.

Phytochemical compound and non-cytotoxicity effect of sting bee and stingless bee honey against normal human gingival cell lines

Objective: Both honeybees (Apis spp.) and stingless bees (Trigona spp.) produce honeys which normally taken orally, have high nutritional and therapeutics value. Until recently, phytochemical comparison of both honey is still scarce and elucidating cytotoxicity effects on human gingival fibroblast cells (HGF) in oral cavity is of interest. Materials and Methods: Kelulut honey (KH), acquired from the stingless bees and acacia honey (AH) from the sting bees honey samples were underwent GC-MS analysis to ascertain their composition. HGF were exposed to various concentrations of KH and AH from the lowest 0.015% to the highest 5% by MTT assay for 24h, 48h and 72h. Results: GC-MS analysis determined various beneficial compounds such as flavonoids, furans, pyrans, levoglucosan and hydroxymethylfurfural from both of honey samples. MTT assay showed that the HGF cells demonstrated good viability up to percentages (v/v) as high as almost 2% in both honeys. The IC50 values for both honey for all time frames fall at above 2%. Conclusion: Both honey showed good survivability of HGF cells up to 2% of concentration. Bangladesh Journal of Medical Science Vol. 21(1) 2022 Page : 158-164

In Vitro Antimicrobial and Cytotoxicity Activities of Some Medicinal Plant Extracts against Oral Microbial Pathogens

Introduction: Medicinal plants have long been of great interest to scientists in the search for the best treatment of diseases, especially the infectious diseases. In recent years, the use of herbal medicines has become more well-known because of their antimicrobial, antifungal, anti-cancer and less side effects. Aim: The aim of this study was to investigate the antimicrobial and antifungal effects of Urtica dioica, Equisetum arvense, and Punica Granatum peel extracts on two common oral microorganisms, Streptococcus mutans and Candida albicans. Materials and methods: The study investigated the hydro-alcoholic extract of the plants. The antimicrobial activity of the extracts was evaluated using the method of measuring the inhibition of microorganisms, and the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) were determined using different concentrations of the extracts and also biofilm assay and SEM were determined. Also cell viability was assessed by MTT assay on human gingival fibroblast cells. Results: The lowest MIC against S. mutants and C. albicans was related to the hydro-alcoholic extract of U. dioica. There was a significant reduction in the microbial biofilms by all three extracts. Among them, U. dioica could decrease the biofilms of S. mutans and C. albicans more than other extracts. In addition, the best results for growth inhibition zone were the hydro-alcoholic extracts of E. arvense and U. dioica with 35 and 30 mm growth zone, respectively. The results of SEM showed that P. granatum peel, U. dioica and E. arvense could destroy microbial biofilms without exerting any cytotoxic effects on HGF cell. Conclusions: The results of the study suggest that U. dioica, E. arvense, and P. Granatum peel extracts can be used as mouthwash with the least significant difference with routine mouthwashes. Also, the plant-based mouthwashes may be more suitable substitutes for chemical types in the future.

THE INFLUENCE BETWEEN INJECTABLE PLATELET-RICH FIBRIN AND PLATELET-RICH PLASMA TOWARDS GINGIVAL FIBROBLAST CELL PROLIFERATION

ABSTRACTBackground: Gingiva is the outermost periodontal tissue that acts as a mechanical and biological barrier to the root of the teeth and alveolar bone. The main cellular elements in the gingiva are fibroblasts. Fibroblast cell proliferation is an important process in tissue regeneration. Growth factors that can stimulate fibroblast cell proliferation can be found in regenerative agents, such as injectable platelet-rich fibrin (i-PRF) and platelet-rich plasma (PRP). The aim of this study was to examine the influence between i-PRF and PRP on the gingival fibroblast cell proliferation in vitro study on primary cell culture.Method: Gingival fibroblast cell were obtained from primary cell culture derived from healthy gingiva. Ten mL of peripheral blood were centrifuged for i-PRF and PRP preparation. The samples were divided into three groups: i-PRF, PRP, and fibroblast cells without treatment. Cell proliferation were observed at day 1, day 3, day 5 using MTT assay at 550 nm. The data were analyzed by Two-Way ANOVA test, followed by Post Hoc test.Result: The results showed that the cell proliferation increased from day 1, 3, and 5 in all groups. The absorbance value of the cell proliferation in order from highest to lowest: i-PRF, PRP, and cell control.Conclusion: i-PRF and PRP increased the gingival fibroblast cell proliferation. i-PRF increased the cell proliferation higher than PRP.

Gingival Epithelial Cell-Derived Microvesicles Activate Mineralization in Gingival Fibroblasts

Soft tissue calcification occurs in many parts of the body, including the gingival tissue. Epithelial cell-derived MVs can control many functions in fibroblasts but their role in regulating mineralization has not been explored. We hypothesized that microvesicles (MVs) derived from gingival epithelial cells could regulate calcification of gingival fibroblast cultures in osteogenic environment. Human gingival fibroblasts (HGFs) were cultured in osteogenic differentiation medium with or without human gingival epithelial cell-derived MV stimulation. Mineralization of the cultures, localization of the MVs and mineral deposits in the HGF cultures were assessed. Gene expression changes associated with MV exposure were analyzed using gene expression profiling and real-time qPCR. Within a week of exposure, epithelial MVs stimulated robust mineralization of HGF cultures that was further enhanced by four weeks. The MVs taken up by the HGF's did not calcify themselves but induced intracellular accumulation of minerals. HGF gene expression profiling after short exposure to MVs demonstrated relative dominance of inflammation-related genes that showed increases in gene expression. In later cultures, OSX, BSP and MMPs were significantly upregulated by the MVs. These results suggest for the first time that epithelial cells maybe associated with the ectopic mineralization process often observed in the soft tissues.

In Vitro Biocompatibility of CPP-ACP and Fluoride-containing Desensitizers on Human Gingival Cells

SUMMARY Objectives: To analyze the biocompatibility of different desensitizers containing casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and fluoride in their composition: MI Varnish (MV), Clinpro White Varnish (3M Oral Care), Profluorid Varnish (VOCO), Duraphat (Colgate) and Embrace Varnish (Pulpdent) on human gingival fibroblast cells (hGF). Methods and Materials: Human gingival fibroblast (hGF) cells were exposed to several desensitizer extracts at different concentrations (0.1%, 1%, and 4% eluates). Then, in vitro biocompatibility was studied by analyzing the IC50 value, cell proliferation (MTT assay and cell cycle), cell migration (wound healing assay), cell morphology and F-actin content (immunocytofluorescence), and induction of apoptosis/necrosis (flow cytometry). Data were analyzed by one-way analysis of variance (ANOVA) followed by Tukey test. Results: The lowest cell viability and IC50 were observed in all concentrations of Embrace Varnish-treated hGFs (p&lt;0.001), whereas the highest were exhibited by those treated with Clinpro White Varnish. Similar effects were evidenced when induction of apoptosis/necrosis and cell migration assays were assessed. Finally, MI Varnish, Profluorid Varnish, Duraphat, and Embrace Varnish extracts showed lower numbers of attached cells, some of them with an unusual fibroblastic morphology when cultured with 4% concentration of the varnishes, while Clinpro White Varnish exhibited a similar number of cells with an evident actin cytoskeleton compared to the control group. Conclusions: The results obtained in this study indicate that hGFs show better in vitro biocompatibility after exposure to Clinpro White Varnish, even at the highest concentration employed, making it the most eligible for topical applications. In contrast, Embrace Varnish exhibited a high cytotoxicity towards hGFs that could potentially delay the healing process and regeneration of the oral mucosa, although more studies are needed to confirm this hypothesis.

Cytotoxic Tumour-Selective 1,5-Diaryl-3-Oxo-1,4-Pentadienes Mounted on a Piperidine Ring

A series of 3,5-bis(benzylidene)-4-piperidones 2a-u were prepared as candidate cytotoxic agents. In general, the compounds are highly toxic to human gingival carcinoma (Ca9-22), human squamous carcinoma-2 (HSC-2) and human squamous carcinoma-4 (HSC-4) neoplasms, but less so towards non-malignant human gingival fibroblast (HGF), human periodontal ligament fibroblast (HPLF) and human pulp cells (HPC), thereby demonstrating tumour-selective toxicity. A further study revealed that most of the compounds in series 2 were more toxic to the human Colo-205 adenocarcinoma cell line (Colo-205), human HT29 colorectal adenocarcinoma cells (HT-29) and human CEM lymphoid cells (CEM) neoplasms than towards non-malignant human foreskin Hs27 fibroblast line (Hs27) cells. The potency of the cytotoxins towards the six malignant cell lines increased as the sigma and sigma star values of the aryl substituents rose. Attempts to condense various aryl aldehydes with 2,2,6,6-tetramethyl-4-piperidone led to the isolation of some 1,5-diaryl-1,4-pentadien-3-ones. The highest specificity for oral cancer cells was displayed by 2e and 2r. In the case of 2r, its selective toxicity exceeded that of doxorubicin and melphalan. The enones 2k, m, o have the highest SI values towards colon cancer and leukemic cells. Both 2e,r inhibited mitosis and increased the subG1 population (with a transient increase in G2/M phase cells). Slight activation of caspase-3, based on the cleavage of poly(ADP-ribose)polymerase (PARP) and procaspase 3, was detected.

Influence of Anodized Titanium Surfaces on the Behavior of Gingival Cells in Contact with: A Systematic Review of In Vitro Studies

Electrochemically anodized (EA) surfaces promise enhanced biological properties and may be a solution to ensure a seal between peri-implant soft tissues and dental transmucosal components. However, the interaction between the modified nano-structured surface and the gingival cells needs further investigation. The aim of this systematic review is to analyze the biological response of gingival cells to EA titanium surfaces in in vitro studies with a score-based reliability assessment. A protocol aimed at answering the following focused question was developed: “How does the surface integrity (e.g., topography and chemistry) of EA titanium influence gingival cell response in in vitro studies?”. A search in three computer databases was performed using keywords. A quality assessment of the studies selected was performed using the SciRAP method. A total of 14 articles were selected from the 216 eligible papers. The mean reporting and the mean methodologic quality SciRAP scores were 87.7 ± 7.7/100 and 77.8 ± 7.8/100, respectively. Within the limitation of this review based on in vitro studies, it can be safely speculated that EA surfaces with optimal chemical and morphological characteristics enhance gingival fibroblast response compared to conventional titanium surfaces. When EA is combined with functionalization, it also positively influences gingival epithelial cell behavior.

Influence of cold atmospheric plasma on dental implant materials — an in vitro analysis

Background and objectives Alterations in the microenvironment of implant surfaces could influence the cellular crosstalk and adhesion patterns of dental implant materials. Cold plasma has been described to have an influence on cells, tissues, and biomaterials. Hence, the mechanisms of osseointegration may be altered by non-thermal plasma treatment depending on different chemical compositions and surface coatings of the biomaterial. The aim of the present study is to investigate the influence of cold atmospheric plasma (CAP) treatment on implant surfaces and its biological and physicochemical side effects. Materials and methods Dental implant discs from titanium and zirconia with different surface modifications were treated with CAP at various durations. Cell behavior and adhesion patterns of human gingival fibroblast (HGF-1) and osteoblast-like cells (MG-63) were examined using scanning electron microscopy and fluorescence microscopy. Surface chemical characterization was analyzed using energy-dispersive X-ray spectroscopy (EDS). Quantitative analysis of cell adhesion, proliferation, and extracellular matrix formation was conducted including real-time PCR. Results CAP did not affect the elemental composition of different dental implant materials. Additionally, markers for cell proliferation, extracellular matrix formation, and cell adhesion were differently regulated depending on the application time of CAP treatment in MG-63 cells and gingival fibroblasts. Conclusions CAP application is beneficial for dental implant materials to allow for faster proliferation and adhesion of cells from the surrounding tissue on both titanium and zirconia implant surfaces with different surface properties. Clinical relevance The healing capacity provided through CAP treatment could enhance osseointegration of dental implants and has the potential to serve as an effective treatment option in periimplantitis therapy.