Journal of Dental Research, Dental Clinics, Dental Prospects
Volume:10 Issue: 2, Spring 2016

This in vitro study compared the effects of mineral trioxide aggregate (MTA), calcium enriched mixture (CEM) cement, Biodentine (BD) and octacalcium phosphate (OCP) on the viability of human gingival fibroblasts (HGFs).
Material and After completion of the setting time of understudy materials, fibroblasts were placed in 24-well insert plates and 1mg of the understudy materials was added to the respective wells. Plates were then incubated at 37°C. Inserts were removed at 24, 48 and 168 hours and2,5-diphenyltetrazolium bromide was added to assess cytotoxicity via the MTT colorimetric assay. Data were analyzed at different time points using repeated measures ANOVA followed by the Bonferroni test at three levels of significance of P Cytotoxicity of the understudy materials was not significantly different at 24 and 48 hours compared to the control group. However, at 168 hours, a significant difference in this regard was noted between MTA and Biodentine with the control group.
Cytotoxicity of MTA, CEM, Biodentine and OCP against HGFs was similar to that of the control group. Over time, MTA and Biodentine showed less cytotoxicity than other materials.

Since it is possible for carbamide peroxide (CP) bleaching agent to contact with amalgam restorations in the oral cavity, the present in vitro study evaluated the amount of dissolved mercury released from amalgam restorations with various percentages of silver content subsequent to the use of 15% CP.
Thirty ANA 2000 amalgam disks with 43.1% silver content and thirty ANA 70 amalgam disks with 69.3% silver content were prepared. In each group, 15 samples were randomly placed in glass tubes containing 15% CP and the remaining 15 samples were placed in buffered phosphate solution (the controls) with the same 3-mL volume of the solution for 48 hours. Subsequently, the amount of mercury dissolved in each test tube was measured using Mercury Analyzing System (Cold Vapor Atomic Absorption, MASLO, Shimadzu, Japan). Data was analyzed with two-way ANOVA and a post hoc Tukey test. (α=0.05)
The amount of mercury released under the influence of CP was significantly higher than that released under the influence of buffered phosphate (P The amount of mercury release is inversely proportional to the silver content of dental amalgam.

Background and Aim of study: Long span is seen in many clinical situations, treatment planning options of these cases are difficult and may require: FPD, RPD or ISP. Each option has its own disadvantages: mechanical, patient relief and cost respectively. This article will evaluate the stress distribution of another treatment option which is adding a single supporting implant to the FPD by using 3D finite element analysis.
Three Models, each consisting of 5units, were created as following: 1.Tooth Pontic Pontic Pontic Tooth. 2.Tooth Pontic Implant Pontic Tooth. 3.Tooth Pontic Pontic Implant Tooth. An axial force was applied to the prostheses by using 3D finite element method and stress was evaluated.
Maximum stress was found in the prostheses in all models, highest stress values in all shared components of the models were close. Stress in implants was less in the second model than the third one.
Adding a supporting implant in long span FPD has no advantages while it has the disadvantages of complicating treatment and the complications that may occur to the implant and surrounding bone itself.

Recurrent aphthous stomatitis (RAS) is one of the most common ulcerative diseases of the oral mucosa. Definitive etiology of RAS has not been conclusively established. There is no certain treatment for aphthous but some drugs such as steroid are commonly used for treatment of RAS. Regarding the effect of Zinc on healing process of epithelial layer and cell division, in this research the effect of the triamcinolone in Orabase, in combination with zinc containing mouthwash and triamcinolone alone on the healing process of RAS lesions is assessed.
The present study consisted of 20 randomly selected patients with major RAS which was diagnosed in Oral Medicine department of Tabriz dental faculty. The patients were instructed to rinse the mouthwash or placebo three times a day, for one month. The largest dimension of the ulcer was measured by digital caliper and the intensity of pain was assessed by VAS. Number, size, duration, ulcer free period and pain of the lesions were evaluated 2 times a week for 2 months. Data were analyzed by SPSS with t- test and Mann Whitney methods.
A decrease was seen in the mean of pain (P= 0.631 ) and the size of the lesions but it was not statistically significant ( P=0.739 ). Also the difference between the number of lesions ( P=0.739 ), duration and ulcer free period( P= 0.873 ) were not statistically significant.
It seems that zinc mouthwash compared with typical treatment for RAS has similar efficacy on wound healing.

Background. Opportunistic fungal infections like candidiasis are common in the oral cavity. In recent years Candida species have shown resistance against a number of synthetic drugs. This study assessed the antifungal activity of Centratherum anthelminticum and Ocimum sanctum seed oils against six common pathogenic Candida strains. Synergistic activity of the major oil components was also studied.
Methods. Antifungal activity of Centratherum anthelminticum and Ocimum sanctum seed oils were tested against six oral fungal pathogens, Candida albicans ATCC 90028, Candida krusei 6258, Candida tropicalis 13803, Candida parapsilosis 22019, Candida glabrata 90030 and Candida dubliniensis MYA 646, by disc diffusion and broth microdilution methods to determine the diameter of inhibition zone (DIZ) and minimum inhibitory concentration (MIC), respectively. The oil was extracted using Soxhlet apparatus from seeds subjected to column chromatography (CC) and thin layer chromatography (TLC) and major components were separated and quantified.
Results. All the six Candida strains showed growth inhibition to a variable degree when tested with both seed oils. Both seed oils showed antifungal activity. For Centratherum anthelminticum seed oil maximum DIZ at 7 µL was recorded at 75.7 mm for Candida albicans ATCC 90028, and the least DIZ was 45.7 mm for Candida dubliniensis MYA 646. For Ocimum sanctum seed oil maximum DIZ at 7 µL was 61.0 mm for Candida krusei ATCC 6258 and the least DIZ was 46.7 mm for Candida tropicalis ATCC 13803. The mixtures of phospholipids and unsaponifiable matter exhibitedMIC values at 1.25 µL for both oils, whereas neutral lipids fraction and unsaponifiable matter exhibited similar MIC at 2.5 µL against Candida albicans and Candida krusei.
Conclusion. Centratherum anthelminticum and Ocimum sanctum seed oils exhibited strong antifungal activity against six different species of Candida and this may be attributed to various active components in the oil and their synergistic activity.

Elastomeric chains and NiTi coil springs are two major traction aids in orthodontic tooth movements. Force degradation occurs over time in both groups, with higher percentages in elastic chains. The effects of environmental factors and some mouth rinses on this force decay have been previously studied. No study has been performed to evaluate the effect of current popular mouth rinses such as Orthokin, Sensikin and Persica on this force degradation.
Forty pieces of elastic chains consisting of 5 loops (Ortho Technology, USA) and 40 NiTi closed coil springs (3M Unitek, Germany) were divided into 4 groups: control (artificial saliva), Orthokin mouthwash, Sensikin mouthwash and Persica mouthwash. All the groups were kept in an incubator at 37°C for 3 weeks. In the test groups, the samples were immersed in mouthwash twice a day. Force productions were measured at 5 time intervals: baseline, 1 hour, 24 hours, 1 week and 3 weeks, using a digital force gauge. Repeated-measures ANOVA and one-way ANOVA were used for statistical analysis.
Overall force decay occurred over time in both elastic chain and coil spring groups. In elastic chain group, after 3 weeks, Orthokin mouth rinse had significantly lower force degradation compared to other groups (P0.05).
According to the results of this study, these three mouthwashes did not increase the force degradation of these orthodontic traction aids.

Any decrease in friction between orthodontic wire and bracket can accelerate tooth movement in the sliding technique and result in better control of anchorage. The present study was carried out to decrease this friction by coating of zinc oxide nanoparticles (ZnO) on orthodontic wires and porcelain brackets.
In this in vitro study, a combination of 120 0.019×0.025 stainless steel(SS) orthodontic wires and porcelain brackets of 0.022 system with and without spherical zinc oxide nanoparticle coating were evaluated. Spherical ZnO nanoparticles were deposited on wires and brackets by immersing them in ethanol solution and SEM (scanning electron microscope) evaluation confirmed the presence of the ZnO coating. The frictional forces were calculated between the wires and brackets in four groups: group ZZ (coated wire and bracket), group OO (uncoated wire and bracket), group ZO (coated wire and uncoated bracket) and group OZ (uncoated wire and coated bracket).Kolmogorov-Smirnov, Kruskal-Wallis and Mann-Whitney tests were used for data analysis.
The frictional force in ZZ (3.07±0.4 N) was the highest (p The coating of ZnO nanoparticles on the surface of porcelain brackets can decrease friction in the sliding technique .

This study investigated the reinforcing effect of silica nanoparticles when incorporated into the matrix phase of an experimental dental fiber reinforced composites (FRC) through the evaluation of the flexural properties of the composites.
In this experimental study FRC samples were divided into two main groups (containing two or three bundles) either of them consist of five subgroups incorporating 0, 0.2, 0.5, 2 and 5 wt.% of silica nanoparticles in the matrix resin (n=10 in each subgroup); While a commercial FRC (Angelus, Brazil) was used as control group (n=10). Three point bending test was performed for evaluating the flexural strength and modulus. Thereafter, the microstructure of the fractured samples was evaluated using scanning electron microscopy (SEM). The results were analyzed using one way ANOVA and Tukey's HSD tests.
The results revealed that the silica nanoparticles had a significant positive effect on the flexural strength and modulus of the FRCs (P0.05) in either groups incorporating two or three bundles of fibers.
Incorporating silica nanoparticles into the FRC resin phase resulted in the composites with improved properties.