Immunohistochemical localization of type IV collagen and laminin (alpha1) in denture stomatitis

Management of Chronic Atrophic Candidiasis (Denture Stomatitis)-A Narrative Review

One of the most common oral diseases affecting people wearing dentures is chronic atrophic candidiasis or denture stomatitis (DS). The aim of the paper is to provide an update on the pathogenesis, presentation, and management of DS in general dental practice settings. A comprehensive review of the literature published in the last ten years was undertaken using multiple databases, including PubMed via MEDLINE, EMBASE, and Scopus. The eligible articles were analyzed to identify evidence-based strategies for the management of DS. Despite its multifactorial nature, the leading cause of DS is the development of oral Candida albicans biofilm, which is facilitated by poor oral and denture hygiene, long-term denture wear, ill-fitting dentures, and the porosity of the acrylic resin in the dentures. DS affects between 17 and 75% of the population wearing dentures, with a slight predominance in elderly females. The mucosal denture surfaces and posterior tongue are the common sites of DS, and the affected areas exhibit erythema, the swelling of the palatal mucosa and edema. Oral and denture hygiene protocols, adjusting or re-fabricating poorly adapting dentures, smoking cessation, avoiding nocturnal denture wear, and the administration of topical or systemic antifungals are the mainstay of management. Alternate treatments such as microwave disinfection, phytomedicine, photodynamic therapy, and incorporation of antifungals and nanoparticles into denture resins are being evaluated for the treatment of DS but require further evidence before routine use in clinical practice. In summary, DS is the most common oral inflammatory lesion experienced by denture wearers. Most patients with DS can be managed in general dental practice settings. Effective management by general dental practitioners may be supported by a thorough understanding of the pathogenesis, the recognition of the clinical presentation, and an awareness of contemporary treatment strategies.

Efficacy of curcumin in the treatment of denture stomatitis: A randomized double-blind study

Background

The prevalence of denture stomatitis has been shown to vary from 15% to 65% in complete denture wearers. In recent years, a number of studies across the globe have investigated the various biological effects of curcumin, curcumin, a polyphenolic compound derived from dietary spice turmeric, possesses diverse pharmacologic effects including anti-inflammatory, antioxidant, antiproliferative and antiangiogenic activities. The aim of this study was to evaluate the efficacy of curcumin local application with common antifungal agent clotrimazole for the treatment of denture stomatitis.

Materials and Methods

A randomised double-blind clinical trial with approval of institutional ethical committee consisting fifty participants divided into two groups (17 men-33 women) with the clinical signs and symptoms of oral candidiasis. The diagnosis was supported by microbiological cultures. Group A patients were prescribed the clotrimazole and Group B patients were prescribed the curcumin ointment which was dispensed in similar amber coloured bottles. Data were analyzed using Chi-squared tests, Wilcoxon's signed rank sum test and Mann-Whitney test.

Results

The mean candidal colony counts before treatment in Groups A and Group B were 63.960 and 37.080, respectively. The mean candida colony counts after treatment in both the groups were 14.080 and 3.720, respectively. There was a statistically significant difference between the two groups when mean candida colony counts were calculated before and after treatment. However, intergroup comparison between the two groups considering the mycological eradication showed that there was no statistically significant difference with P = 0.404.

Conclusion

Topical application of curcumin as a natural ingredient could be an effective agent for the treatment of denture stomatitis as an alternative to regular clotrimazole therapy.

Mutual concessions and compromises between stromal cells and cancer cells: driving tumor development and drug resistance

BACKGROUND

Various cancers have been found to be associated with heterogeneous and adaptive tumor microenvironments (TMEs) and to be driven by the local TMEs in which they thrive. Cancer heterogeneity plays an important role in tumor cell survival, progression and drug resistance. The diverse cellular components of the TME may include cancer-associated fibroblasts, adipocytes, pericytes, mesenchymal stem cells, endothelial cells, lymphocytes and other immune cells. These components may support tumor development through the secretion of growth factors, evasion from immune checkpoints, metabolic adaptations, modulations of the extracellular matrix, activation of oncogenes and the acquisition of drug resistance. Here, we will address recent advances in our understanding of the molecular mechanisms underlying stromal-tumor cell interactions, with special emphasis on basic and pre-clinical information that may facilitate the design of novel personalized cancer therapies.

CONCLUSIONS

This review presents a holistic view on the translational potential of the interplay between stromal cells and cancer cells. This interplay is currently being employed for the development of promising preclinical and clinical biomarkers, and the design of small molecule inhibitors, antibodies and small RNAs for (combinatorial) cancer treatment options. In addition, nano-carriers, tissue scaffolds and 3-D based matrices are being developed to precisely and safely deliver these compounds.

Microenvironmental regulation of the progression of oral potentially malignant disorders towards malignancy

Oral potentially malignant disorders (OPMD) develop in a complex tissue microenvironment where they grow sustainably, acquiring oral squamous cell carcinoma (OSCC) characteristics. The malignant tumor depends on interactions with the surrounding microenvironment to achieve loco-regional invasion and distant metastases. Unlike abnormal cells, the multiple cell types in the tissue microenvironment are relatively stable at the genomic level and, thus, become therapeutic targets with lower risk of resistance, decreasing the risk of OPMD acquiring cancer characteristics and carcinoma recurrence. However, deciding how to disrupt the OPMD and OSCC microenvironments is itself a daunting challenge, since their microenvironments present opposite capacities, resulting in diverse consequences. Furthermore, recent studies revealed that tumor-associated immune cells also participate in the process of differentiation from OPMD to OSCC, suggesting that reeducating stromal cells may be a new strategy to prevent OPMD from acquiring OSCC characteristics and to treat OSCC. In this review, we discuss the characteristics of the microenvironment of OPMD and OSCC as well as new therapeutic strategies.

Distribution Patterns of E-Cadherin, Type VII Collagen and Fibronectin in Denture-Related Stomatitis: A Preliminary Study

The distribution of epithelial E-cadherin, basement membrane type VII collagen, and underlying connective tissues fibronectin were investigated immunohistochemically and compared in normal palatal mucosa and in denture-related stomatitis (DRS) derivatives using monoclonal antibodies.Biopsies of palatal mucosa were obtained from twelve patients enrolled in this study, 8 with type II DRS and 4 with healthy mucosa.Our findings bring to the fore, using the expression of three components (E-cadherin, collagen type VII, fibronectin), the continuities of the disorder among epithelial, basement membrane and connective tissue in the case of DRS. In type II denture-related stomatitis, we found an expression of E-cadherinin all the strata of epithelia, and the diffuse and strong expression of type VII collagen at the interface between connective tissue and epithelial cells with discontinuities in BM. The strong expression of fibronectin in underlying connective tissue with penetration in some areas of the palatal mucosa may be an early consequence of advanced DRS. Nevertheless; no single change is pathognomonic of this inflammatory process.In normal tissues (healthy clinical aspect), E-cadherin was found to be restricted to the upper strata of the epithelia, and type VII collagen revealed thin linear staining in the basement membrane and fibronectin in underlying connective tissue combined epithelia.In the case of denture-related stomatitis DRS, these three markers reflect the immunohistological modifications from the superficial layer of the epithelium to the lamina propria.

Association of human papillomavirus with denture wearing

AIM

  To determine the prevalence of human papillomavirus in the oral cavity of denture wearers.

METHODS

  Swabs were collected from 72 denture wearers and 72 controls (non-denture wearers) to obtain DNA. Amplification of the β-globin gene was performed by polymerase chain reaction to check the integrity of extracted DNA. The presence of human papillomavirus in the DNA sample was detected by nested polymerase chain reaction.

RESULTS

  The prevalence of human papillomavirus was found to be significantly higher in the oral cavity of denture wearers (38/72, 52.8%) than in the controls (17/72, 23.6%; odds ratio = 3.612, confidence interval = 1.771/7.385, P = <0.001). When adjusted for variables, including age, sex, ethnicity, and smoking habit, human papillomavirus was still found to be significantly associated with denture wearing, with an adjusted odds of 3.2 (P = 0.008). No association of human papillomavirus positivity was found with denture variables, including denture type, denture material type, duration of denture wearing, and denture hygiene (P > 0.05). Low-risk human papillomavirus types were found to be more frequent in both groups.

CONCLUSIONS

  The prevalence of human papillomavirus in the oral cavity of denture wearers was found to be significantly higher compared to controls; however, it was mainly low-risk types.

Favoring Trauma as an Etiological Factor in Denture Stomatitis

The etiology of denture stomatitis remains controversial. Trauma due to unstable dentures has been suggested as an etiological factor. Therefore, we tested the hypothesis that the prevalence of denture stomatitis is reduced when mandibular dentures are stabilized by implants. Data were collected at a one-year follow-up from 173 edentulous elders who had randomly received mandibular implant overdentures or conventional dentures. The diagnosis of denture stomatitis was determined according to the Newton classification. Elders wearing conventional dentures were almost 5 times more likely to have denture stomatitis than those wearing mandibular two-implant overdentures ( P < 0.0001, Fisher’s exact test). Adjusted odds ratios showed that only the type of the prosthesis (AOR = 4.54, 95% CI 2.20 to 9.40) and nocturnal wear (AOR = 3.03, 95% CI 1.24 to 7.40) predict the frequency of denture stomatitis. Thus, implant overdentures may reduce oral mucosal trauma and control denture stomatitis.

The role of candida in inflammatory papillary hyperplasia of the palate

The objective of this study was to investigate the expression by immunohistochemistry of the major basement membrane (BM) components (laminin, collagen type IV, fibronectin) in specimens from the palatal mucosa lesions of patients with complete dentures and diagnosis of inflammatory papillary hyperplasia of the palate (IPHP). Furthermore to evaluate the potential role of candidal infection in patients with IPHP. Biopsies of palatal mucosa were obtained from patients with IPHP, generally healthy/orally healthy patients with dentures, and healthy subjects. Immunohistochemical studies performed with specific antibodies to BM proteins. Scrapings and swaps of oral lesions from all patients and control groups were taken from the palate, and Candida species colonization was assessed with mycology tests. Immunohistochemical expression of BM components revealed thin linear staining in the BM of healthy palatal mucosa. In IPHP discontinuities or disruptions in BM were observed at the interface between epithelium and the underlying connective tissue in the areas of severe inflammatory response. Our findings suggest an interaction between the expression of BM components and Candida involvement in the development of IPHP, a disorder involving inflammatory reaction and modification of soft tissues.

Prognosis of oral pre-malignant lesions: significance of clinical, histopathological, and molecular biological characteristics

The concept of a two-step process of cancer development in the oral mucosa, i.e., the initial presence of a precursor subsequently developing into cancer, is well-established. Oral leukoplakia is the best-known precursor lesion. The evidence that oral leukoplakias are pre-malignant is mainly derived from follow-up studies showing that between < 1 and 18% of oral pre-malignant lesions will develop into oral cancer; it has been shown that certain clinical sub-types of leukoplakia are at a higher risk for malignant transformation than others. The presence of epithelial dysplasia may be even more important in predicting malignant development than the clinical characteristics. Three major problems, however, are attached to the importance of epithelial dysplasia in predicting malignant development: (1) The diagnosis is essentially subjective, (2) it seems that not all lesions exhibiting dysplasia will eventually become malignant and some may even regress, and (3) carcinoma can develop from lesions in which epithelial dysplasia was not diagnosed in previous biopsies. There is, therefore, a substantial need to improve the histologic assessment of epithelial dysplasia or, since epithelial dysplasia does not seem to be invariably associated with or even a necessary prerequisite for malignant development, it may be necessary to develop other methods for predicting the malignant potential of pre-malignant lesions. As a consequence of these problems, numerous attempts have been made to relate biological characteristics to the malignant potential of leukoplakias. Molecular biological markers have been suggested to be of value in the diagnosis and prognostic evaluation of leukoplakias. Markers of epithelial differentiation and, more recently, genomic markers could potentially be good candidates for improving the prognostic evaluation of precursors of oral cancer. As yet, one or a panel of molecular markers has not been determined that allows for a prognostic prediction of oral pre-cancer which is any more reliable than dysplasia recording. However, these new markers could be considered complementary to conventional prognostic evaluation.