Effectiveness of coating acrylic resin dentures on preventing Candida adhesion.

PURPOSE: The aim of this study was to prevent the adhesion of C. albicans on acrylic resin dentures by modifying their surfaces. MATERIALS AND METHODS: Ninety acrylic resin plates were divided into three groups. Group I: conventionally processed acrylic resin plates. Group II: plates painted with 2-Octyl Cyanoacrylate adhesive. Group III: plates painted with Adper Single Bond Adhesive. All specimens were immersed separately in containers filled with artificial saliva that contained C. albicans and then incubated for 11 days at 37°C. Three methods of evaluation were used to count the adhered Candida: direct culture, slide count, and serial dilutions. RESULTS: C. albicans in 1/10, 1/10², and 1/10³ dilutions showed overgrowth in group I, while overgrowth was noted only with 1/10 dilution in group III. For group III, mean colony numbers of 123, 22, 3.4, and 0 were found for the 1/10², 1/10³, 1/104, and 1/105 dilutions, respectively. Regarding the slide counts, group I showed a mean fungal count of 166 compared to 40 for group III with 1/10 dilution, 21 compared to 9 with 1/10³ dilution, 8.6 compared to 0.7 with 1/10³ dilution, and 1.2 compared to 0 with 1/104 dilution. No plates in group II showed any candidal colonies regardless of the method of evaluation (0%). These differences were statistically significant (p < 0.0001). CONCLUSION: Coating the acrylic resin dentures with Adper Single Bond Adhesive was effective in reducing C. albicans adhesion to dentures, while coating with 2-Octyl Cyanoacrylate adhesive completely inhibited such adhesion.

TNFα Signaling Is Increased in Progressing Oral Potentially Malignant Disorders and Regulates Malignant Transformation in an Oral Carcinogenesis Model.

Oral carcinogenesis represents a multi-stage process which encompasses several genetic and molecular changes that promote the progression of oral potentially malignant disorders (OPMDs) to oral squamous cell carcinomas (OSCCs). A better understanding of critical pathways governing the progression of OMPDs to OSCCs is critical to improve oncologic outcomes in the future. Previous studies have identified an important role of tumor necrosis factor α (TNFα) and TNF receptor 1 (TNFR1) in the invasiveness of oral cancer cell lines. Here, we investigate the expression of TNFα and TNFR1 in human OPMDs that progress to OSCC compared to non-progressing OPMDs utilizing fluorescent immunohistochemistry (FIHC) to show increased TNFα/TNFR1 expression in progressing OPMDs. In order to interrogate the TNFα/TNFR1 signaling pathway, we utilized a 4-nitroquinoline 1-oxide (4-NQO) mouse model of oral carcinogenesis to demonstrate that TNFα/TNFR1 expression is upregulated in 4-NQO-induced OSCCs. TNFα neutralization decreased serum cytokines, inhibited the development of invasive lesions and reduced tumor-associated neutrophils in vivo. Combined, this data supports the role of TNFα in oral malignant transformation, suggesting that critical immunoregulatory events occur downstream of TNFR1 leading to malignant transformation. Our results advance the understanding of the mechanisms governing OSCC invasion and may serve as a basis for alternative diagnostic and therapeutic approaches to OPMDs and OSCC management.

Increase in detection of oral cancer and precursor lesions by dentists: Evidence from an oral and maxillofacial pathology service.

BACKGROUND: Dentists play an important role in the detection and diagnosis of oral diseases, including oral cancer and its precursor lesions. There are few comprehensive reviews in the recent literature that examine the scope and trends of oral disease diagnoses by dentists. METHODS: The authors analyzed all accessions to the Toronto Oral Pathology Service at the Faculty of Dentistry at the University of Toronto in Toronto, Ontario, Canada, from 2005 through 2015 using a custom-built database. They used these data to calculate the temporal trends in the diagnoses of oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC). RESULTS: A total of 63,483 biopsy specimens were submitted primarily by dentists from 2005 through 2015. From these, 2,679 cases of OED and 828 OSCC were diagnosed. The authors' results show a 3.8-fold increase in the number of epithelial dysplasias and a 1.8-fold increase in mucosal carcinomas over the study period. The rate of increase of OED and OSCC was significantly higher than the rate of increase of total oral carcinomas diagnosed in the region, the population changes, and the number of dentists in the region. CONCLUSIONS AND PRACTICAL IMPLICATIONS: Within the limitations of a study of a single large oral pathology biopsy service, the analysis of diagnoses shows that dentists are increasingly involved in the detection of oral mucosal carcinoma and precursor lesions. The dental community plays an important and increasing role in the detection of oral cancer and potentially malignant disorders. Increased awareness among oral health care and nonoral health care professionals may increase early detection of OSCC.

Desmoid tumor of the tongue.

Desmoid tumors are rare neoplasms accounting for 0.03% of all neoplasms and have an estimated incidence of 2 to 4 per million per year. World Health Organization currently refers to all of the deep types of fibromatosis as desmoid-type of fibromatoses. The term "desmoid" refers to the hard, tendon-like appearance of the tumor. The etiological factors suggested include genetic, endocrine and physical factors. About fifty percent of desmoid tumors arise in the abdominal region. The extra-abdominal desmoid tumors present a difficult problem in recognition and management especially because of the striking discrepancy between its deceptively harmless microscopic appearance and its potential to attain a large size, to recur, and to infiltrate neighboring tissues in the manner of a fibrosarcoma. Desmoid tumors are very rare in the oral cavity with less than 5% of cases constituting oral soft tissue fibromatosis. A 22-year old mentally retarded female patient with desmoid tumor occurring in the tongue is presented here.

The importance of ctokeratins in the early detection of oral squamous cell carcinoma.

BACKGROUND: Oral cancer is usually diagnosed at advanced stages. The pattern of keratin expression in normal epithelia and the change in their expression in premalignant lesions and carcinomas have suggested the possibilities of improving diagnosis. The aim of this study is to determine the use of acidic cytokeratins (CKs) as biomarkers of histopathological progression in oral carcinogenesis. MATERIALS AND METHODS: A total of 50 paraffin blocks of histological specimens diagnosed as hyperplastic epithelium, dysplastic epithelium, well-differentiated squamous cell carcinoma (SCC) and poorly-differentiated SCC (10 specimens each) were included in this study, in addition to 10 normal oral mucosal samples. All samples were stained immunohistochemically with CKs (10-ab1, 14, 16-ab1, 18-dc10 and 19-abs10) using Ventana Medical Systems (Arizona-USA). The expression of CKs antigen was evaluated as absent, mild, moderate and severe. RESULTS: CK10-ab1 was found to be positive in the suprabasal layers of all specimens in normal and hyperplastic epithelium, while it was moderate in dysplastic epithelium and mild in well-differentiated SCC. CK10-ab1 was negative in all samples with poorly-differentiated SCC (P < 0.005). CK14 was positive in all specimens of all groups whereas CK16-ab1 was negative in all specimens of all groups. The stain of CKs 18-dc10 and 19-abs10 was restricted to the basal cells only in normal, hyperplastic and dysplastic epithelium, while it was mild in well-differentiated and poorly-differentiated SCC (P < 0.01). CONCLUSION: CK10-ab1 disappeared gradually with the progression of malignant changes of squamous cells whereas CKs 18-dc10 and 19-abs10 increased gradually at the same time. Such changes in the protein mapping of squamous cells need more investigation for a better understanding of oral SCC.

Inhibitory effect of zirconium oxide nanoparticles on Candida albicans adhesion to repaired polymethyl methacrylate denture bases and interim removable prostheses: a new approach for denture stomatitis prevention.

BACKGROUND: Despite drawbacks, cold-cured acrylic resin is still the most common material used in denture repair. Zirconia nanoparticles were among the reinforcements added to increase the strength of the resin. The effect on Candida due to the addition of zirconia nanoparticles to the resin has not been investigated. PURPOSE: The aim of this study was to evaluate the effect of zirconia nanoparticles added to cold-cured acrylic resin on Candida albicans adhesion. MATERIALS AND METHODS: A total of 120 acrylic resin specimens with dimensions measuring 22×10×2.5 mm3 were prepared and divided into two equal groups. One group (repair) comprised heat-polymerized specimens that were sectioned at the center and prepared to create a 2 mm repair area that was repaired with cold-cured resin reinforced with 0% wt, 2.5% wt, 5% wt, and 7.5% wt zirconia nanoparticles. The second group contained intact cold-cured acrylic resin specimens reinforced with 0% wt, 2.5% wt, 5% wt, and 7.5% wt zirconia nanoparticles. Specimens were incubated at 37°C in artificial saliva containing C. albicans, and the effect of zirconia nanoparticles on C. albicans was assessed using two methods: 1) a slide count method and 2) a direct culture test. Variations in the number of living Candida were observed in relation to the different concentrations of zirconia nanoparticles. Analysis of variance (ANOVA) and post hoc Tukey's tests were performed for data analysis. If the P-value was ≤0.05, then the difference was considered as statistically significant. RESULTS: It was found that C. albicans adhesion to repaired specimens was significantly decreased by the addition of zirconia nanoparticles (P<0.00001) in comparison with the control group. Intact cold-cured groups and groups repaired with cold-cured resin reinforced with 7.5% wt zirconia nanoparticles showed the lowest Candida count. Tukey's test showed a significant difference between the repaired group and the intact cold-cured group, while the later demonstrated a lower Candida count. CONCLUSION: The addition of zirconia nanoparticles to cold-cured acrylic resin is an effective method for reducing Candida adhesion to repaired polymethyl methacrylate (PMMA) denture bases and cold-cured removable prosthesis. CLINICAL SIGNIFICANCE: Based on the results of the current study, zirconia nanoparticles have an antifungal effect, which could be incorporated in the repair material for repairing denture bases and in PMMA removable prostheses as a possible approach for denture stomatitis prevention.

In Vitro Evaluation of the Inhibitory Activity of Thymoquinone in Combatting Candida albicans in Denture Stomatitis Prevention.

Candida albicans adhesion and proliferation on denture bases may lead to denture stomatitis, which is a common and recurrent problem in denture wearers. The goal of this study was to assess the inhibitory effect of thymoquinone incorporated in the polymethyl methacrylate denture base material against Candida albicans. Eighty acrylic resin specimens were fabricated and divided into eight groups (n = 10) according to thymoquinone concentrations of 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, and 5% of acrylic powder. Two methods were used to evaluate the effect of thymoquinone on Candida albicans: the slide count and the serial dilution test. A multivariate analysis of variance (MANOVA) and the post-hoc Tukey's Honestly Significant Difference (HSD) test were performed to compare the difference of means between the observations taken at various intervals with baseline. The p value was statistically significant at ≤0.05. According to the slide count and the serial dilution test, the mean number of adhered Candida albicans in the control group was 5436.9 ± 266 and 4691.4 ± 176.8; however, this number dramatically decreased to 0 ± 0 and 32.4 ± 1.7 in group 8 (concentration 5%). These results suggest that the incorporation of thymoquinone into the acrylic resin denture base material might be effective in preventing Candida albicans adhesion.

Pulpal Responses to Direct Capping with Betamethasone/Gentamicin Cream and Mineral Trioxide Aggregate: Histologic and Micro-Computed Tomography Assessments.

INTRODUCTION: This clinical trial was conducted to evaluate the response of human dental pulp to direct capping with betamethasone/gentamicin (BG) cream and mineral trioxide aggregate (MTA). We hypothesized that the results of direct pulp capping with a topical BG combination would be similar to or better than those with MTA. METHODS: Thirty-six human first premolar teeth scheduled for orthodontic extraction were randomly divided into 4 groups: BG1 group (n = 9), BG cream with 2-week follow-up; BG2 group (n = 10), BG cream with 8-week follow-up; MTA1 group (n = 8), MTA with 2-week follow-up; and MTA2 group (n = 9), MTA with 8-week follow-up. Teeth were extracted and evaluated at respective time intervals. Micro-computed tomography scanning and histologic analyses were performed for all specimens. Pulp pathology (inflammation, pulp abscesses, and pulp necrosis) and reparative reaction (formation of dentin bridges) were recorded. RESULTS: Both BG cream and MTA resulted in significantly better pulpal responses at 8 weeks than at 2 weeks. Dentin bridge formation was significantly thicker in the MTA group at 8 weeks than in any other group (P < .05). Inflammation was of the acute type in all groups; no statistically significant differences in the distribution of inflammatory cells were found among the groups. Pulpal abscesses and/or necrosis were observed more often in teeth capped with BG than with MTA. CONCLUSIONS: Direct pulp capping with both BG cream and MTA was associated with dentin bridge formation. MTA resulted in a significantly better pulpal response, with less inflammation and a thicker dentin bridge at 8 weeks.

Antifungal Effect of Henna against Candida albicans Adhered to Acrylic Resin as a Possible Method for Prevention of Denture Stomatitis.

Denture stomatitis is a very common disease affecting the oral mucosa of denture wearers. The aim of this study was to measure the antifungal effect of henna against Candida albicans adhered to acrylic resin as a possible method for prevention of denture stomatitis. One-hundred-eighty acrylic plates were prepared of heat-cured acrylic denture resin. The specimens were divided into six groups of 30 samples each. The first group was only polymer and monomer following the conventional manufacturer instruction for processing complete dentures. The other five groups were processed by adding different concentration of Yamani henna powder (Harazi) to the polymer in a concentration of henna: polymer 1%, 2.5%, 5%, 7.5% and 10%, respectively. Samples were incubated in artificial saliva rich with Candida albicans at 37 °C, and the effect of henna on Candida albicans was evaluated in two different methods: semi-quantitative slide count and a culture-based quantitative assay (quantitative). Variation in the number of live Candida was observed with the increase in the concentration of Yamani henna powder. It was observed that the variation in live Candida, between control group and group B (concentration of Yamani henna powder was 1%), was statistically significant with a p-value of 0.0001. Similarly, variations in live Candida were significant, when the concentration of powder was 7.5% or 10% in contrast with control group and p-values were 0.0001 and 0.001 respectively. Adding henna to acrylic resin denture could be effective in controlling Candida albicans proliferation on the denture surface; however, its effects on the physical properties of acrylic resin denture need further studies.

Prevalence of denture-related oral lesions among patients attending College of Dentistry, University of Dammam: A clinico-pathological study.

BACKGROUND: Heterogeneous groups of oral lesions are likely to develop among denture wearers. The objectives of this study were to determine the exact prevalence of oral lesions among denture wearers attending the clinics of the College of Dentistry, University of Dammam. MATERIALS AND METHODS: All denture wearers attending the dental clinics in the period between January 2012 and April 2013 were included in this study. Of the total 210 patients, 166 (79%) were males and 44 (21%) were females. Comprehensive oral examination was performed for all patients. Any denture-induced lesion was biopsied. Data collected were analyzed using SPSS program. RESULTS: Oral lesions were found in 20.5% of the cases under study (43 out of the total 210 denture wearers). Denture-induced fibrous hyperplasia was the most common type of lesion detected (41.9%). A significant correlation (P = 0.004) was found between the type of denture and oral lesions in this study. CONCLUSION: The prevalence of denture-induced oral lesions was found to differ significantly from that reported in other studies. The diversity of these lesions among different studies depends on the quality and materials of dentures delivered, the techniques used, and the methods of patients' instructions adopted.

The relationship between the location of thyroglossal duct cysts and the epithelial lining.

Thyroglossal duct cysts (TDCs) with ambiguous epithelial lining are the most common midline cervical anomaly encountered in children. To histopathologically study the epithelial lining of 32 thyroglossal duct cysts in relation to their locations. A total of 32 cases of thyroglossal duct cysts were collected for this study. The samples were classified into 3 groups as follows: (1) above the hyoid bone; (2) at the level of hyoid bone; (3) below the hyoid bone. All samples were H&E stained. Seventeen TDCs (53 %) were found above the hyoid bone, 6 (18.8 %) were found at the level of hyoid bone and 9 (28.1 %) were found below the hyoid bone. Of the 32 total cases, 6 (18.8 %) were lined with stratified squamous epithelium (SSE), 17 (53 %) were lined with pseudostratified ciliated epithelium (PSCE), 3 (9.4 %) were lined with stratified cuboidal epithelium (SCE), and 6 (18.8 %) exhibited both SSE and PSCE. Pseudostratified ciliated epithelium was dominant in the region superior to the hyoid bone, whereas SCE was detected only in TDCs at the level of hyoid bone. These differences were statistically significant (P = 0.0001). Different types of epithelial lining were detected in the study samples of TDCs. A statistically significant correlation was found between the type of epithelium detected and the location of the TDC at the time of diagnosis.

Qat habit in Yemen society: a causative factor for oral periodontal diseases.

The effect of a common habit among Yemeni population on the periodontal status was investigated. This cross-sectional study was done on 2500 Yemenis with mean age 27.01 years (1818 males and 682 females). Among these 1528 were qat chewers and 972 were non-chewers. Detailed questionnaire and pre-designed scoring system for the periodontal status were employed for each case. Study results indicated that out of 972 non-chewers 116(12%) had periodontal pocketing and 18 (1.9%) cases had gingival recession. On the other hand, out of 1528 chewers, 468 (31.8%) had periodontal pockets and 98 (6.4%) with gum bleeding, p<0.05. These effects were found to increase with increased frequency and duration of chewing. It was concluded that habit of qat can cause damage to the periodontal ligament as pocketing and gum recession.

Histopathologic changes in oral mucosa of Yemenis addicted to water-pipe and cigarette smoking in addition to takhzeen al-qat.

BACKGROUND: Because the clinicopathologic effects of takhzeen al-qat are similar to those induced by smoking, the aim of this paper was to study the oral effect of 3 bad oral habits: takhzeen al-qat and cigarette and water-pipe smoking. STUDY DESIGN: This study was done on 33 Yemeni chronic qat users grouped as heavy cigarette smokers (GI), nonsmokers (GII) and water-pipe smokers (GIII). In all cases (n = 33) 2 biopsies were taken (n = 66), one from the buccal mucosa at the chewing side and the other from a similar mucosa at the contralateral (nonexposed) side. Biopsies were prepared for routine H&E staining. RESULTS: Acanthosis appeared in 88% and 0%, abnormal rete ridges in 70% and 3%, hyperparakeratosis in 67% and 0%, and epithelial dysplasia in 30% and 0% of the chewing and nonchewing sides, respectively, in the 3 groups. Epithelial dysplasia appeared in 41% of GI and GIII (smokers) but in only 9% of GII (nonsmokers). CONCLUSIONS: Takhzeen al-qat causes distinct histopathologic changes in the oral mucosa at the side of chewing, such as acanthosis, abnormal rete ridges, and hyperparakeratosis. The association between takhzeen al-qat and cigarette or water-pipe smoking may increase the risk of epithelial dysplasia.

Histopathological changes in oral mucosa due to takhzeen al-qat: a study of 70 biopsies.

BACKGROUND: Chewing qat leaves (takhzeen al-qat) is a common habit in East Africa and Yemen. It has been reported to cause different systemic effects. At the oral mucosa, it causes clinical changes that appear as white lesions. The aim of this paper was to study the histopathological changes in the oral mucosa related to takhzeen al-qat. METHOD: Seventy biopsies were studied. Biopsies were divided into three groups: (G1) Forty biopsies were taken from the oral mucosa of the chewing side. (G2) Twenty biopsies were taken from the oral mucosa of the opposite side and (G3) 10 biopsies were taken from the oral mucosa of non-chewing volunteers. All biopsies were conventionally prepared, paraffin embedded and histopathological protocol was followed for each case to study the histopathological changes. RESULTS: Acanthosis appeared in 97.5% (G1) and 50% (G2), parakeratosis in 45% (G1) and 0% (G2), orthokeratosis in 25% (G1) and 10% (G2), abnormal rete ridges in 97.5% (G1) and 25% (G2), intracellular edema in 80% (G1) and 65% (G2), inflammatory infiltration in the subjacent connective tissue of 55% (G1) and 5% (G2), increased amount of collagenous fibers in 47.5% (G1) and 0% (G2), and mild epithelial dysplasia in 25% (G1) and 0% (G2). Biopsies taken from G3 showed no histopathological changes except one case with intracellular edema. Differences were statistically significant. CONCLUSION: Takhzeen al-qat caused histopathological changes in the oral mucosa at the side of chewing; however, these changes were innocuous and without any evidence of malignancy.

A study of 342 oral keratotic white lesions induced by qat chewing among 2500 Yemeni.

BACKGROUND: Qat chewing is a common habit in Yemen. Various studies demonstrated clear effects of this habit on the systemic organs of the human body. The lack of studies, however, on the effects of this habit on oral mucosa was the major motive of this study. METHODS: This cross-sectional study was made on 2500 Yemeni citizens (mean age 27 years, 1818 males and 682 females). Clinical protocol was made for all cases with a full intraoral examination. A new grading system was applied for each case with oral white lesion. RESULTS: Of our sample, 1528 cases (61.12%) were qat chewers; of them, 342 cases (22.4%) had oral keratotic white lesions at the site of qat chewing, while only 6 (0.6%) non-chewer cases had white lesions in their oral cavity (P < 0.000000, Odds ratio = 46.43, RR = 36.26). According to our grading system; 14, 5.9 and 2.4% were grade I, II and III. CONCLUSIONS: We conclude that qat chewing can provoke the development of oral keratotic white lesions at the site of chewing. The prevalence of these lesions and its severity increase as duration and frequency increase.