Role of Vitamin D and Vitamin D Receptor in Oral Lichen Planus: A Systematic Review

BACKGROUND: Oral lichen planus (OLP) is known to be a chronic inflammatory disease associated with various other systemic disorders. Studies have shown that vitamin D deficiency can be involved in the pathogenesis of lichen planus. The aim of this study was to investigate the role of vitamin D and vitamin D receptor in OLP.METHODS: In this review study, all English and Persian articles were searched by relevant keywords from the Google scholar, PubMed, science direct, Cochrane, Scopus and Sid databases until January 2020.RESULTS: From the 16 articles obtained after reviewing the abstracts, finally 14 appropriate articles were included in this study.CONCLUSION: According to the results of the studies, vitamin D deficiency may be associated with an increased risk of OLP lesions

Effect of hemostatic agent on marginal gaps of class V giomer restorations

Contamination of dentin with hemostatic agents might exert a deleterious effect on adhesive procedures on dentin. The present study was undertaken to investigate the effect of aluminum chloride hemostatic agent on marginal gaps in Cl V giomer restorations. Fifty sound bovine permanent incisors were selected for the purpose of this in vitro study and Cl V cavities were prepared on their buccal surfaces; the gingival margins of the cavities were placed in dentin. The tooth samples were randomly assigned to two groups (n=25). The samples in groups 1 and 2 underwent a restorative procedure without and with the application of aluminum chloride hemostatic agent in the cavity, respectively, before application of the adhesive. BeautiBond one-step self-etch adhesive and Beautifil II giomer restorative material were used for the restoration of the cavities in both groups. The samples were thermocycled and sectioned, followed by measuring the gap sizes at gingival margins in µm under a stereomicroscope. The marginal gaps were compared with Mann-Whitney U test. Statistical significance was set at P<0.05. The results showed significant differences in the mean marginal gaps between the two groups under study (P<0.001); the mean marginal gaps were higher in group 2 (with hemostatic agent) compared to those in group 1 (without hemostatic agent) (P<0.0005). Contamination with aluminum chloride hemostatic agent in giomer restorations gave rise to higher gingival margin gaps

Effect of disinfecting the cavity with chlorhexidine on the marginal gaps of Cl V giomer restorations

Considering the effect of cavity disinfecting agents on the bonding and sealing ability of restorations bonded to dentin, the aim of this study was to evaluate the effect of chlorhexidine (CHX) disinfecting agent on the marginal gaps of Cl V giomer restorations. Cl V cavities were prepared on the buccal surfaces of 60 sound bovine permanent incisors in this in vitro study, with the occlusal and gingival margins in enamel and dentin, respectively. The teeth were randomly divided into two groups (n=30). The teeth in groups 1 and 2 were restored without and with the use of the disinfecting agent in the cavity, respectively, before applying the adhesive. BeautiBond one-step self-etch adhesive and Beautifil II giomer were used to restore the cavities in both groups. After thermocycling and sectioning of the samples, the sizes of marginal gaps at gingival margins were measured in µm under a stereomicroscope. Mann-Whitney U test was used to compare marginal gaps at P<0.05 level of significance. The means of marginal gaps were significantly different between the two study groups (U=180, P<0.001), with higher means of marginal gaps in group 2 (with CHX disinfection) compared to group 1 (without CHX disinfection) (P<0.0005). Application of CHX for the disinfection of cavities in giomer restorations resulted in an increase in gingival margin gaps

Effect of surface preparation with Nd:YAG and Er,Cr:YSGG lasers on the repair bond strength of lithium disilicate glass ceramic to a silorane - based composite resin

Background. This study was undertaken to evaluate the repair bond strength of lithium disilicate glass ceramic to a silorane - based composite resin after surface prep aration with Nd:YAG and Er,Cr:YSGG lasers. Methods. A total of 102 lithium disilicate glass ceramic samples (IPS e.max Press), measuring 5 mm in diameter and 4 mm in thickness, were randomly assigned to 6 groups (n=17): group 1, no surface preparation (control); group 2, acid etching wit h 9.5% hydrofluoric acid (HF); group 3, surface preparation with 4.5 - W Nd:YAG laser; g roup 4, surface preparation with 6 - W Nd:YAG laser; group 5, surface preparation with 1.5 - W Er,Cr:YSGG laser; and group 6, surface preparation with 6 - W Er,Cr:YSGG laser. After preparation of surfaces and application of silane, all the samples were repaired with the use of a silorane - based composite resin, followed by storage in distilled water at a temperature of 37°C for 24 hours and thermocycling. Finally, the samples were subjected to a shearing bond strength test; the fracture modes were determined under a stereomi- croscope. Results. There were significant differences between the HF group and the other groups (P=0.000). Two - by - two comparisons of the other groups revealed no significant differences (P>0.05). Conclusion . Use of HF proved the most effective s urface preparation technique to increase the repair bond strength between lithium disilicate glass ceramic and silorane - based composite resin; compared to the control group

Effect of aluminum chloride hemostatic agent on microleakage of class V composite resin restorations bonded with all-in-one adhesive

Objectives: Since hemostatic agents can induce changes on enamel and dentin surfaces and influence composite resin adhesion, the aim of the present study was to evaluate the effect of the aluminum chloride hemostatic agent on the gingival margin microleakage of class V (Cl V) composite resin restorations bonded with all-in-one adhesive. Study design: Cl V cavities were prepared on the buccal surfaces of 60 sound bovine permanent incisors. Gingival margins of the cavities were placed 1.5 mm apical to the cemento-enamel junction (CEJ). The teeth were randomly divided into two groups of 30. In group 1, the cavities were restored without the application of a hemostatic agent; in group 2, the cavities were restored after the application of the hemostatic agent. In both groups all-in-one adhe sive and Z250 composite resin were used to restore the cavities with the incremental technique. After finishing and polishing, the samples underwent a thermocycling procedure, followed by immersion in 2% basic fuschin solution for 24 hours. The samples were sectioned and gingival microleakage was evaluated under a stereomicroscope. The non-parametric Mann-Whitney U test was used to compare microleakage between the two groups. Statistical significance was defined at P<0.05. Results: A statistically significant difference was observed in microleakage between the two groups (P<0.001). Conclusions: Contamination of Cl V composite resin restorations bonded with all-in-one adhesive with aluminum chloride hemostatic agent significantly increases restoration gingival margin microleakage

Role of interleukin-4 in pathogenesis of oral lichen planus : a systematic review

Oral lichen planus (OLP) is a premalignant mucocutaneous disease that affects 1-2% of the adult population. Immunological factor may act as etiological factor. The cellular immune cells such as T cells are important in pathogenesis of OLP. Interleukin-4 (IL-4) is secreted by T-helper 2 (Th2). Several studies have been carried out on the role of IL-4 in OLP. The aim of this study was to review the level of IL-4 in OLP, effective factors in the production of IL-4 and its role in the development of OLP. A search in PubMed was performed on the literature published from 2000 until august 2019 using the following keywords: ?oral lichen planus? or ?OLP? and ?interleukin-4? or ?IL-4?. Originally, 37 articles were considered, of which 28 case-control articles were selected according to the inclusion/exclusion criteria. This review study shows that IL-4 plays a key role in the development of OLP. According to the past studies, there are several factors contributing to the production of this cytokine. Identification of the routes of production of IL-4 and its role in OLP might be useful for development of new preventive and therapeutic methods in management of patients with OLP

The Effect of Different Mixing Methods on the Properties of Calcium-enriched Mixture Cement: A Systematic Review of in Vitro Studies

Introduction: It has been shown that the mechanical and physical properties of Calcium Enriched Mixture (CEM) cement are influenced by the mixing methods. Despite several studies conducted on different mixing methods of CEM cement, there is no systematic review to summarize the results. This systematic review was conducted to investigate the effect of different mixing techniques on mechanical and physical characteristics of CEM cement. Methods and Materials: A professional librarian with skills in informatics conducted a systematic search by searching electronic databases PubMed/MEDLINE and Scopus and Ovid for English language peer-reviewed articles published between 1992 and April 2019. Results: Initial searches from all sources identified 1175 references. Two of the authors examined the titles, abstracts of these articles and the full reports of 20 studies were obtained, and data extraction was performed. Seven studies satisfied the eligibility criteria for the review. The effect of different mixing methods was investigated on bacterial microleakage, push-out bond strength, flow rate, compressive strength, solubility, pH, film thickness, dimensional changes, working time, setting time and quality of the apical plug. Conclusion: Based on the results of this systematic review, some of the important properties of CEM cement were affected by different mixing methods. Although none of these mixing methods could improve all the properties, mechanical and manual methods were more effective compared to ultrasonic method.  Keywords: Calcium-enriched Mixture Cement; Systematic Review; Ultrasoni

Effect of 10% sodium ascorbate on Streptococcus mutans adherence to bleached bovine enamel surface

Sodium ascorbate has been suggested to modify bleaching agents’ side effects especially on composite resin bonding to dental hard tissues. The aim of the present study was to evaluate the effect of 10% sodium ascorbate on Streptococcus mutans adherence to bleached enamel surfaces. Sixty enamel slabs from bovine incisors were used. After sterilization of the intact enamel surfaces with UV light, the specimens were randomly divided into the following treatment groups: (1) immersion in normal saline containing 2%NaN3; (2) bleaching of enamel surfaces with 10% carbamide peroxide; (3) bleaching of enamel surfaces with 10% carbamide peroxide followed by 10% sodium ascorbate treatment. Adherence of S. mutans to enamel surfaces was determined bacteriologically. Data was analyzed using one-way ANOVA and post hoc Tukey tests (P &lt; 0.05).10% sodium ascorbate after bleaching (Group 3) caused a significant increase in surface adherence of S. mutans compared to groups 1 and 2 (P &lt; 0.001). Because of bacterial adherence subsequent to use of sodium ascorbate to bleached enamel caries risk may be increased.Keywords: Sodium ascorbate, Streptococcus mutans, carbamide peroxideAfrican Journal of Biotechnology Vol. 9(33), pp. 5419-5422, 16 August, 201

Effect of Various Laser Surface Treatments on Repair Shear Bond Strength of Aged Silorane-Based Composite

Introduction: Successful repair of composite restorations depends on a strong bond between the old composite and the repair composite. This study sought to assess the repair shear bond strength of aged silorane-based composite following surface treatment with Nd:YAG, Er,Cr:YSGG and CO2 lasers.Methods: Seventy-six Filtek silorane composite cylinders were fabricated and aged by 2 months of water storage at 37°C. The samples were randomly divided into 4 groups (n = 19) of no surface treatment (group 1) and surface treatment with Er,Cr:YSGG (group 2), Nd:YAG (group 3) and CO2 (group 4) lasers. The repair composite was applied and the shear bond strength was measured. The data were analyzed using one-way analysis of variance (ANOVA) and Tukey post-hoc test. Prior to the application of the repair composite, 2 samples were randomly selected from each group and topographic changes on their surfaces following laser irradiation were studied using a scanning electron microscope (SEM). Seventeen other samples were also fabricated for assessment of cohesive strength of composite.Results: The highest and the lowest mean bond strength values were 8.99 MPa and 6.69 MPa for Er,Cr:YSGG and control groups, respectively. The difference in the repair bond strength was statistically significant between the Er,Cr:YSGG and other groups. Bond strength of the control, Nd:YAG and CO2 groups was not significantly different. The SEM micrographs revealed variable degrees of ablation and surface roughness in laser-treated groups.Conclusion: Surface treatment with Er,Cr:YSGG laser significantly increase the repair bond strength of aged silorane-based composite resin