Reversal of drug-induced gingival overgrowth by UV-mediated apoptosis of gingival fibroblasts - an in vitro study

Virus-Mediated Inhibition of Apoptosis in the Context of EBV-Associated Diseases: Molecular Mechanisms and Therapeutic Perspectives

Epstein-Barr virus (EBV), the representative of the Herpesviridae family, is a pathogen extensively distributed in the human population. One of its most characteristic features is the capability to establish latent infection in the host. The infected cells serve as a sanctuary for the dormant virus, and therefore their desensitization to apoptotic stimuli is part of the viral strategy for long-term survival. For this reason, EBV encodes a set of anti-apoptotic products. They may increase the viability of infected cells and enhance their resistance to chemotherapy, thereby contributing to the development of EBV-associated diseases, including Burkitt’s lymphoma (BL), Hodgkin’s lymphoma (HL), gastric cancer (GC), nasopharyngeal carcinoma (NPC) and several other malignancies. In this paper, we have described the molecular mechanism of anti-apoptotic actions of a set of EBV proteins. Moreover, we have reviewed the pro-survival role of non-coding viral transcripts: EBV-encoded small RNAs (EBERs) and microRNAs (miRNAs), in EBV-carrying malignant cells. The influence of EBV on the expression, activity and/or intracellular distribution of B-cell lymphoma 2 (Bcl-2) protein family members, has been presented. Finally, we have also discussed therapeutic perspectives of targeting viral anti-apoptotic products or their molecular partners.

Er,Cr:YSGG Laser Therapy for Drug-Induced Gingival Overgrowth: A Report of Two Case Series

Background

Drug-induced gingival overgrowth is common but neglected in patients with systemic disease medications until it seriously affects the quality of life.

Methods

Initial periodontal treatment, combined with water laser surgery, was performed sequentially in two cases.

Results

The therapeutic effect was good, and there was no recurrence along with good oral hygiene.

Conclusion

Water laser equipment surgery, as well as initial periodontal treatment, required that surgeons are trained specifically. A tool was devised for various oral diseases, and it was safer, more efficient and more comfortable than others.

Biomineralization potential and biological properties of a new tantalum oxide (Ta2O5)-containing calcium silicate cement

Objective

The present study evaluated the biological effects and biomineralization potential of a new tantalum oxide (Ta₂O₅)–containing material designed for vital pulp therapy or perforation repair (NeoMTA 2), compared to NeoMTA Plus and Bio-C Repair.

Material and methods

Human dental pulp stem cells (hDPSCs) were exposed to different eluates from NeoMTA Plus, NeoMTA 2, and Bio-C Repair. Ion release from each material was determined using inductively coupled plasma-optical emission spectrometry (ICP-MS). The biological experiments performed were MTT assays, apoptosis/necrosis assays, adhesion assays, migration assays, morphology evaluation, and reactive oxygen species (ROS) production analysis. Biomineralization was assessed by Alizarin red S staining. Finally, osteo/odontogenic gene expression was determined by real-time quantitative reverse-transcriptase polymerase chain reaction (RT-qPCR). Data were analyzed using one-way ANOVA followed by Tukey’s multiple comparison test.

Results

NeoMTA 2 displayed a significantly higher calcium release compared to the other materials (p < 0.05). When hDPSCs were cultured in presence of the different material eluates, all groups exhibited similar hDPSC viability and migration rates when compared to untreated cells. Substantial cell attachment and spreading were observed in all materials’ surfaces, without significant differences. hDPSCs treated with NeoMTA 2 displayed an upregulation of ALP, Col1A1, RUNX2 (p < 0.001), ON, and DSPP genes (p < 0.05), and showed the highest mineralization potential compared to other groups (p < 0.001). Finally, the more concentrated eluates from these materials, specially NeoMTA Plus and NeoMTA 2, promoted higher ROS production in hDPSCs compared to Bio-C Repair and control cells (p < 0.001), although these ROS levels did not result in increased cell death.

Conclusions

The new tantalum oxide (Ta₂O₅)–containing material shows an adequate cytocompatibility and the ability to promote biomineralization without using chemical osteogenic inducers, showing great potential as a new material for vital pulp therapy.

Clinical relevance

NeoMTA 2 seems to be a promising material for vital pulp therapy. Further studies considering its biocompatibility and biomineralization potential are necessary.

Topical fluoride varnishes promote several biological responses on human gingival cells

OBJECTIVE

To compare the in vitro cytotoxicity of four commercial topical fluoride varnishes widely used in daily dental practice for the prevention of caries on human fibroblasts: Cervitec F, Fixofluor, Fluor Protector S and Duraphat.

MATERIAL AND METHODS

Human gingival fibroblasts (hGF) were exposed to different concentrations of fluoride varnishes extracts. Biological assays, including MTT and IC50 value determination, annexin-V/7-AAD staining, cell migration and F-actin staining with phalloidin were carried out. Statistical analyses were performed using one-way ANOVA and Tukey's post hoc test.

RESULTS

At 4% concentration, all of the fluoride varnishes extracts affected fibroblasts metabolic activity, exhibiting a high degree of cytotoxicity at all measured time points. At 0.1% and 1%, Duraphat and Fixofluor or Fluor Protector S and Cervitec F exerted the lowest or highest cytotoxic effects, respectively. Similar effects were evidenced when induction of apoptosis/necrosis and cell migration assays were analyzed. Immunocytochemical assays revealed a similar number of fibroblasts, without changes in the morphology and F-actin content at 0.1% concentration of all tested materials, while at 1% concentration, Fluor Protector S and Cervitec F showed few cells with aberrant morphology or non-adhered cells, respectively.

CONCLUSIONS

Different commercial topical fluoride varnishes with the same therapeutic indication may exhibit different biological effects and cytotoxicity on fibroblasts.

The dentomaxillary apparatus from molecular biology to variational anatomy-Underpinning interdisciplinary research

Over the past decades, the research environment in anatomy has dramatically changed. Studies have become more interdisciplinary and complex, with many components required, from basic to clinical research. Within this framework, this special issue was designed to create a link between fundamental fields such as developmental and molecular biology, dental materials, anatomy, histology, and their applications in the clinical research of the dentomaxillary apparatus.

Periodontal Management of Cyclosporin A-Induced Gingival Overgrowth: A Nonsurgical Approach

Gingival overgrowth is a major and frequent unwanted effect accompanying the chronic usage of antihypertensive, anticonvulsant, and immunosuppressant drugs. The expression and the severity of this tissue-specific condition are influenced by a variety of factors, mainly drug and periodontal variables. Such increased volume of gingiva may compromise normal oral functions, aesthetics in addition to the patients' ability to practice optimal oral hygiene. The management of gingival overgrowth includes nonsurgical approach, surgical approach, or both of them for severe cases of gingival overgrowth as well as drug withdrawal. This case report illustrates a successful nonsurgical management of a 21-year-old patient with cyclosporin A-induced gingival overgrowth who experienced a total regression of the gingival enlargement without any surgical procedure or drug substitution. And it highlights therefore the key role of supportive periodontal therapy in maintaining good and stable outcomes over 2 years of follow-up.

Cyclosporine A - Induced gingival overgrowth and proliferating cell nuclear antigen expression in experimental periodontitis

The most important microscopic characteristic of Cyclosporine A-induced gingival overgrowth is fibroepithelial hyperplasia.

OBJECTIVE

The objective was to investigate the influence of previous exposure to Cyclosporine A over gingival epithelium in experimental periodontitis in rats.

METHODS

Twenty Wistar rats with 12 weeks-old were divided into four groups with 5 animals each: Control Group (CG); Cyclosporine Group (CsAG); Ligature group (LG) and Cyclosporine and Ligature Group (CsALG). Daily doses of CsA (10 mg/kg) were applied to CsAG and CsALG during 60 days since the beginning of the experiment and, a ligature was placed in LG and CsALG 30 days after the beginning of the experiment. After 60 days, animals were euthanized and gingival tissue was processed to histomorphometric analysis of epithelial thickness (mm²), immunohistochemical expression of PCNA (%) and inflammatory response. Data were analyzed by Kruskal-Wallis and Mann Whitney at 0.05 significance level.

RESULTS

Considering epithelial thickness, CG was thinner than all groups, CsALG was the largest and CsAG and LG were similar between each other. Regarding the PCNA expression CG (16.46 ± 9.26) was similar to CsAG (34.47 ± 19.75) and, LG (59.02 ± 10.33) was similar to CsALG (40.59 ± 18.25). Significant difference (p < 0.05) occurred only in inflammation presence comparing CG/LG and CsAG/CsALG. A weak positive correlation between the number of PCNA+ and inflammatory cells (p = 0.001; r = 0.611) was observed.

CONCLUSION

Based on these results it was concluded that the enlargement of gingival epithelium observed in experimental periodontitis can be increased by previous exposition to CsA and inflammatory conditions enhanced proliferative activity of the keratinocytes.