Association of the Risk of Dental Caries and Polymorphism of MBL2 rs11003125 Gene in Iranian Adults.

This case-control study aimed to investigate the effect of rs11003125 in dental caries. For this purpose, a total number of 404 individuals - from Fars Province in Iran - were studied. The technique of this research was the tetra-primer amplification-refractory mutation system (ARMS)-PCR. Dental caries prevalence among the 404 individuals was assessed by counting the number of decayed, missing, and filled teeth. In this research, individuals were divided into two groups: cases (n = 238) and controls (n = 166), and the peripheral blood samples were used to extract the genomic DNA. For genotyping of DNA, the tetra-primer ARMS-PCR method was conducted using specific primer pairs. While examining MBL2 rs11003125 polymorphism, we found significant differences in the genotype frequencies between the case and the control group. The pooled estimates indicated that the GG and GC genotypes of MBL2 rs11003125 polymorphism significantly increased, and therefore caries risk (OR = 2.40, 95% CI = 1.31-4.40, p = 0.004) under the dominant model. These findings suggested that polymorphism in MBL2 gene was associated with dental caries in Iranian adults. Further verification is needed with more ethnic groups and larger sample sizes to determine whether rs11003125 polymorphism is related to dental caries in other regions or not.

Effect of Silver Nanoparticles, Zinc Oxide Nanoparticles and Titanium Dioxide Nanoparticles on Microshear Bond Strength to Enamel and Dentin.

AIM: This study was aimed to evaluate whether antibacterial pretreatment of enamel and dentin with silver nanoparticles (SNPs), zinc oxide nanoparticles (ZNPs) and titanium dioxide nanoparticles (TNPs) has any effect on the microshear bond strength of an etch-and-rinse adhesive system. MATERIALS AND METHODS: Eighty human third molars were randomly assigned to eight subgroups (n = 10). Enamel groups included no pretreatment (E), pretreatments with SNPs (ESNP), ZNPs (EZNP) and TNPs (ETNP) before acid etching and adhesive application. Dentinal groups included no pretreat-ment (D), pretreatments with SNPs (DSNP), ZNPs (DZNP) and TNPs (DTNP). The specimens were bonded by Adper Single Bond and polyvinyl chloride microtubes and were restored with Z250 composite. The bonded surfaces underwent microshear bond strength (uSBS) test. Data in megapascal (MPa) were analyzed with the Kruskal-Wallis test and the Mann-Whitney test (p = 0.05). RESULTS: There was not a significant difference among the groups in enamel (p > 0.05). There was no significant difference between the application of three nanoparticles and the control group in dentin. However, DSNPs had a higher uSBS (25.60 ± 14.61) than that of the DZNPs and DTNPs groups (p = 0.03 and p = 0.001, respectively). Also, the mean uSBS value was lower in dentin groups compared to the respective enamel groups (p < 0.05) except for groups DSNPs and ESNPs in which no significant difference was found (p > 0.05). CONCLUSION: Pretreatment with SNPs, TNPs, and ZNPs can be suggested to achieve potent antibacterial activities without compromising the bond strength. The best result was obtained for pretreatment with SNPs compared to pretreatment with TNPs or ZNPs in dentin and enamel, albeit the differences were not significant in the enamel groups. CLINICAL SIGNIFICANCE: Effective antibacterial treatment prior to adhesive bonding application is desirable to provide successful restoration if it would not adversely affect the bond strength of the adhesive system. Nanoparticles can be applied to meet this goal.

Comparison of Cytotoxicity of New Nanohybrid Composite, Giomer, Glass Ionomer and Silver Reinforced Glass Ionomer using Human Gingival Fibroblast Cell Line.

AIM: The objective of this study was to investigate the cytotoxic effects of new nanohybrid composite, giomer, conventional and resin modified and silver reinforced glass ionomer cements and compare the biocompatibility of these dental materials in cell culture. STUDY DESIGN: Five cylindrical specimens were made of each material, using a mold (2mm. thick and 5 mm in diameter). For HGF, cells were cultured in RPMI-1640 medium. After attaining 80% confluence, cells were treated with different doses of five tested materials for 24h. Then cell cytotoxicity was assessed using MTT assay. The data were analyzed using Kruskal-Wallis and Dunn test. RESULTS: The materials evaluated on HGF cells, showed significantly more cytotoxicity in silver reinforced glass ionomer but nanohybrid composite shows mild cytotoxic effect. However, giomer shows no significant cytotoxicity and conventional and resin modified glass ionomer enhance cell proliferation. CONCLUSIONS: Silver reinforced glass ionomer induced a significant high cytotoxic effect over a wide range of concentration. Therefore, higher attention should be focused on this restorative dental material, which should be chosen for further investigations.

Role of TiF4 in Microleakage of Silorane and Methacrylate-based Composite Resins in Class V Cavities.

AIM: This study investigated the effect of TiF4 solution pretreat-ment on microleakage of silorane and nanofilled methacrylate-based composites in class V cavities. MATERIALS AND METHODS: Forty-eight intact premolar teeth were randomly allocated to four groups of 12 teeth. Restorative techniques after standard class V tooth preparations were as follows: Group 1, Filtek P90 composite; group 2, Filtek Z350 XT; group 3, TiF4 solution pretreatment and Filtek P90 composite; group 4, TiF4 solution pretreatment and Filtek Z350 XT. After storing the specimens in distilled water at 37°C for 24 hours and followed by immersion of the specimens in a 0.5% basic-fuchsin solution for 24 hours, they were sectioned buccolingually to obtain four surfaces for each specimen for analysis of microleakage using a stereomicroscope. Data analysis was performed using Kruskal-Wallis test to compare the four groups and the Mann-Whitney test for paired comparisons with Statistical Package for the Social Sciences (SPSS) version 17 software. RESULTS: At the enamel margins, microleakage score of the Filtek Z350 XT group was lower than those of the Filtek P90 with and without the application of the TiF4 (p = 0.009 and p = 0.031 respectively). At the dentin margins, groups 3 and 4 (TiF4+Filtek P90 and TiF4+Filtek z350 XT respectively) showed significantly lower microleakage than group 1 (Filtek P90). However, there was no significant difference between other groups (p > 0.05). CONCLUSION: At the enamel margins, microleakage score of the silorane-based composite was more than that of the nanofilled composite. No significant differences were observed between the other groups. At the dentin margins, for the silorane-based composite restorations, TiF4 solution pretreatment resulted in significantly lower microleakage. However, the similar result was not observed for Filtek Z350 XT. Also, no significant difference was observed between microleakage scores of Filtek P90 and Filtek Z350 XT with or without TiF4 pretreatment. CLINICAL SIGNIFICANCE: In spite of better mechanical and physical properties of modern composites than earlier methacrylate-based composites, polymerization shrinkage has been remaining as one of the main shortcomings of them. Different methods, such as using new low shrinkage resin composites and different dentin pretreatments, have been suggested to overcome this problem. This study evaluated the effect of TiF4 as pretreatment on microleakage of class V tooth preparations restored with a nanocomposite and a silorane-based resin composite.

The LncRNA H19 rs217727 Polymorphism Is Associated with Oral Squamous Cell Carcinoma Susceptibility in Iranian Population.

Lack of protein-coding capacity is a main characteristic of long noncoding RNAs (lncRNAs) which, as molecular biomarkers, have found a novel pharmacological application in cancer and are reported to be important regulators of gene expression. H19 is reportedly involved in cancer progression and tumorigenesis. One of the most common types of head and neck cancers is oral squamous cell carcinoma (OSCC). The main objective of the present study was to evaluate the correlation of OSCC susceptibility with H19 gene in an Iranian population. This research was performed on 400 subjects of both sexes referred to the Namazi Hospital affiliated with the Shiraz University of Medical Sciences (SUMS). Individuals aged 15-88 years were divided into two groups: pathologically diagnosed patients with new-onset OSCC and healthy controls. After written and informed consent was obtained from the individuals, genomic DNA was extracted. The tetra-primer ARMS-PCR technique was performed for DNA genotyping by the use of specific primer pairs. The susceptibility of OSCC and H19 gene polymorphism sites was further analyzed (rs217727 and rs2107425). The allele and genotype frequencies of H19 rs2107425 polymorphism were similar between OSCC cases and controls. The H19 rs217727T allele frequency was significantly higher in OSCC cases (P = 0.002), and the polymorphism of H19 rs217727 was associated with OSCC susceptibility in the codominant (OR = 6.04, 95%CI = 1.70 - 21.42, P = 0.001 for TT genotype), dominant (OR = 1.62, 95%CI = 1.08 - 2.43, P = 0.01), and recessive (OR = 5.32, 95%CI = 1.51 - 18.69, P = 0.003) models. This study showed that rs217727 and OSCC susceptibility were statistically correlated in the Iranian population.

AMELX Gene Association with Dental Caries in Iranian Adults.

Dental decay is a disease that is greatly affected by environmental components, but recently there have been an increasing number of documents supporting a genetic factor in the development of caries. The purpose of this study was to examine the association between dental caries and single-nucleotide polymorphisms in the AMELX gene. This research was carried out on 360 individuals of both sexes, who were referred to the dental school at the Shiraz University of Medical Sciences. In this research, individuals aged 20-65 years were divided into two groups: controls (decayed, missed, or filled teeth (DMFT) ≤ 5; n = 180) and cases (DMFT ≥ 14; n = 180). The tetra-primer ARMS-PCR technique was performed for genotyping the DNA extracted from blood cells. Analysis of the AMELX rs946252 polymorphism showed that the T allele of rs946252 was a significant protective factor against dental caries in Iranian adults (T vs. C: OR = 0.70, 95% CI: 0.49-0.98, P = 0.04). We demonstrated the significant differences in the genotype frequencies under two genetic models: overdominant (TC vs. TT + CC: OR 0.35, 95% CI 0.19-0.64, P = 0.0006) and recessive (CC vs. TC + TT: OR 2.57, 95% CI 1.39-4.76, P = 0.002). Our results show that the SNPs of the AMELX gene may be related with susceptibility to dental caries in Iranian adults.

Influence of silver nanoparticles on resin-dentin bond strength durability in a self-etch and an etch-and-rinse adhesive system.

OBJECTIVES: This study evaluated the effect of dentin pretreatment with silver nanoparticles (SNPs) and chlorhexidine (CHX) on the microshear bond strength (µSBS) durability of different adhesives to dentin. MATERIALS AND METHODS: Occlusal surfaces of 120 human molars were ground to expose flat dentin surfaces. The specimens were randomly assigned to six groups (n = 20). Three groups (A, B, and C) were bonded with Adper Single Bond 2 (SB) and the other groups (D, E, and F) were bonded with Clearfil SE Bond (SEB). Dentin was pretreated with CHX in groups B and E, and with SNPs in groups C and F. The specimens were restored with Z250 composite. Half of the bonded surfaces in each group underwent µSBS testing after 24 hours and the other half was tested after 6 months of water storage. RESULTS: SNP application was associated with a higher µSBS than was observed in the CHX and control groups for SEB after 24 hours (p < 0.05). A significantly lower µSBS was observed when no dentin pretreatment was applied compared to dentin pretreatment with CHX and SNPs for SB after 24 hours (p < 0.05). The µSBS values of the 6-month specimens were significantly lower than those obtained from the 24-hour specimens for all groups (p < 0.05). This decrease was much more pronounced when both adhesives were used without any dentin pretreatment (p < 0.05). CONCLUSIONS: SNPs and CHX reduced the degradation of resin-dentin bonds over a 6-month period for both adhesive systems.

The Effect of Incorporation of 0.5 %wt. Silica Nanoparticles on the Micro Shear Bond Strength of a Resin Modified Glass Ionomer Cement.

STATEMENT OF THE PROBLEM: The clinical success of glass ionomer restorations depends on the strength of resin-modified glass ionomer (RMGI) cement bonding to dentin and there is limited information available regarding the bond strength of resin modified glass ionomers containing silica nanoparticles to dental structures. PURPOSE: The aim of this study was to compare the microshear bond strength (µSBS) of RMGI with and without silica (SiO2) nanoparticles to dentin of permanent teeth. MATERIALS AND METHOD: In this experimental study, the occlusal surfaces of 30 freshly extracted intact third molars were ground to expose the flat dentin and after conditioning with 20% poly acrylic acid, were randomly assigned to two main groups (n=15). The first group was filled with RMGI (Fuji II LC, GC) and the second group was filled with RMGI plus 0.5%wt. silica nanoparticles. Then, each main group was divided into three subgroups, and then stored in an incubator at 37 oC with 100% humidity for 1, 7, and 30 days. The µSBS test was performed using a universal testing machine (1 mm/min). The data were analyzed by t-test, repeated measures ANOVA and Tukey test (p< 0.05). RESULTS: There were no statistically significant differences between the mean µSBS of the groups with and without nanoparticles along the different storage periods (p> 0.05). There was significant difference in µSBS values among the three different storage periods in all the tested materials (p< 0.05). CONCLUSION: Incorporation of 0.5 %wt. silica nanoparticles did not compromise the µSBS of Fuji II LC RMGI to dentin.

The Effect of Titanium Tetrafluoride and Sodium Hypochlorite on the Shear Bond Strength of Methacrylate and Silorane Based Composite Resins: an In-Vitro Study.

STATEMENT OF THE PROBLEM: The bond strength of composites with different adhesive systems with dentin is an important factor in long term durability of composite restorations. The effect of titanium tetrafluoride (TiF4) as anti caries agent and sodium hypochlorite (NaOCl) as disinfectant on the shear bond of nanofilled and silorane based composite resins have not been investigated in previous studies. PURPOSE: This study was conducted to determine bond strength between dentin and two composite systems, by means of shear bond test using TiF4 and NaOCl. MATERIALS AND METHOD: Middle dentin of 60 intact extracted maxillary premolar teeth were exposed by sectioning the crowns at a depth of 2mm from central groove and parallel to the occlusal surface. Standardized smear layer was created using a 600-grit silicon carbide paper and then samples were embedded in acrylic resin blocks. Then the samples were randomly divided into 6 \groups summarized as Group I: Z350, Group II: Z350+ NaOCl, Group III: Z350+ TiF4, Group IV: P90, Group V: P90+ NaOCl, Group VI: P90+ TiF4 according to manufacturer's instruction. Then samples were subjected to shear bond strength (SBS) test using universal testing machine and data were analyzed using ANOVA and Tukey tests (p< 0.05). RESULTS: Application of 5% NaOCl caused a significant decrease in SBS of nanofilled composite resin (p= 0.004), and also silorane based composite resin (p= 0.006). Application of 4% TiF4 caused a significant increase in SBS of silorane based composite resin (p= 0.001). The effect of TiF4 on nanofilled composite was not statistically significant. CONCLUSION: Using TiF4 has a positive effect on increasing the shear bond while NaOCl has negative effect on bond strength.

A comparison inhibitory effects of cisplatin and MNPs-PEG-cisplatin on the adhesion capacity of bone metastatic breast cancer.

To date, high mortality in women due to malignancy breast cancer related to the metastasis to the bone is a significant challenge. As, magnetic nanoparticles (MNPs) conjugated with the biocompatible polymers was employed for the delivery of some hydrophobic anticancer agents, the main aim of the current research was to assess whether cisplatin-loaded MNPs enhanced the anticancer effect of free cisplatin in breast cancer cells. MNPs decorated with PEG were synthesized by an improved coprecipitation technique, and then cisplatin was loaded onto the MNPs via a simple mixing method. Afterward, its morphology, size, chemical structure, magnetic property, hydrodynamic diameter, zeta potential, and crystal structure were characterized by scanning and transmittance electron microscopy, Fourier transforms infrared spectroscopy, vibrating sample magnetometer, dynamic light scattering, and X-ray powder diffraction and flame atomic absorption spectroscopy respectively. Additionally, the effects of cisplatin and MNPs-PEG-cisplatin on viability, migration and adhesion capacity of T47D cells were investigated by evaluating α2-integrin and ß1-integrin; mRNAs were assessed by real-time RT-PCR. Consequently, the in vitro assay results showed a considerable dose-dependent inhibitory effect of cisplatin and MNPs-PEG-cisplatin on proliferation, migration, and adhesion of T47D cells. Finally, current research was shown that MNPs-PEG-cisplatin strongly increased anticancer effects compared with free cisplatin in the T47D cell line.

Shear Bond Strength of Self-Adhering Flowable Composite and Resin-modified Glass Ionomer to Two Pulp Capping Materials.

INTRODUCTION: The aim of this study was to compare the shear bond strength of a self-adhering flowable composite (SAFC) and resin-modified glass ionomer (RMGI) to mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM) cement. METHODS AND MATERIALS: A total of 72 acrylic blocks with a central hole (4 mm in diameter and 2 mm in depth) were prepared. The holes were filled with MTA (sub group A) and CEM cement. The specimens of both restorative materials were divided into 6 groups; overall there were 12 groups. In groups 1 and 4, SAFC was used without bonding while in groups 2 and 5 SAFC was used with bonding agent. In all these groups the material was placed into the plastic mold and light cured. In groups 3 and 6, after surface conditioning with poly acrylic acid and rinsing, RMGI was placed into the mold and photo polymerized. After 24 h, the shear bond strength values were measured and fracture patterns were examined by a stereomicroscope. Data were analyzed using the two-way ANOVA and student's t-test. RESULTS: The use of bonding agent significantly increased the shear bond strength of FC to MTA and CEM cement (P=0.008 and 0.00, respectively). In both materials, RMGI had the lowest shear bond strength values (2.25 Mpa in MTA and 1.32 Mpa in CEM). The mean shear bond strength were significantly higher in MTA specimen than CEM cement (P=0.003). There was a significant differences between fracture patterns among groups (P=0.001). Most failures were adhesive/mix in MTA specimen but in CEM cement groups the cohesive failures were observed in most of the samples. CONCLUSION: The bond strength of self-adhering flowable composite resin to MTA and CEM cement was higher than RMGI which was improved after the additional application of adhesive.

The Effect of Temperature on Shear Bond Strength of Clearfil SE Bond and Adper Single Bond Adhesive Systems to Dentin.

STATEMENT OF THE PROBLEM: Monomer viscosity and solvent evaporation can be affected by the adhesive system temperature. Higher temperature can elevate the vapor pressure in solution and penetration of adhesive in smear layer. Bonding mechanism may be influenced by the adhesive temperature. PURPOSE: This study aimed to evaluate the effect of pre-heating on shear bond strength of etch-and-rinse and self-etching adhesives to ground bovine dentin surfaces, at temperatures of 4˚C, 25˚C and 40˚C. MATERIALS AND METHOD: In this experimental study, 60 maxillary bovine incisors were randomly divided into 6 groups (n=10). The central part of labial dentin surfaces was exposed with a diamond bur and standardized smear layer was created by using silicon carbide paper (600 grit) under water-coolant while the specimens were mounted in acrylic resin. Two adhesive systems, an etch-and-rinse (Adper single bond) and a self-etch (Clearfil SE Bond) were stored at temperatures of 4˚C, 25˚C and 40˚C for 30 minutes and were then applied on the prepared labial surface according to the manufacturer's instructions. The composite resin (Z350) was packed in Teflon mold (5 mm in diameter) on this surface and was cured. The shear bond strength (MPa) was evaluated by universal testing machine (Zwick/Roell Z020, Germany) at cross head speed of 1mm/min. The results were statistically analyzed by using ANOVA and Tukey tests (p< 0.05). RESULTS: No significant difference was found between the shear bond strength of Clearfil SE Bond adhesive in different temperature and single Bond adhesive system at 25 ˚C and 40 ˚C. However, there were significant differences between 4 ˚C of Adper single bond in comparison with 25˚C and 40˚C (p= 0.0001). CONCLUSION: Pre-heating did not affect the shear bond strength of SE Bond, but could promote the shear bond strength of Adper Single Bond.

Evaluation of histological impacts of three types of orthodontic fixed retainers on periodontium of rabbits.

STATEMENT OF THE PROBLEM: Fixed retainers were developed to maintain incisor alignments after orthodontic treatments. Although the effects of fixed retainers on periodontal health are clinically studied, no studies have still evaluated the histological changes in the periodontium after the placement of thefixed retainers. PURPOSE: The aim of this study was to evaluate the effects of customised retainers on periodontium histologically. MATERIALS AND METHOD: Forty pairs of maxillary and mandibular central incisors of twenty rabbits were randomly divided into four equal groups: The first group was considered as the control and in the second group, Fiber Reinforced Composite (FRC), in the third group, 0.014 inch stainless steel (SS) wire and in the fourth group, 0.175 inch multistrand stainless steel (MSS) wire were bonded on the labial surfaces of the incisors. After sixty days; animals' periodontium were evaluated histologically. RESULTS: The number of bone resorption lacuna in the control group was significantly less than FRC and 0.014 SS groups. The periodontal vessel count and their diameter in the control group was significantly lower than the other groups. The pulp vessel count and their diameter in controls were significantly more than the 0.014 SS and the 0.175 MSS groups. CONCLUSION: Findings of this study suggest that FRC fixed retainer might cause detrimental effects on the periodontal ligaments and supporting bone and the 0.014- inch and 0.175- inch fixed retainers can cause hyalinization and possibly the necrosis of the pulp.