Essential oil composition and antioxidant activity of Levisticum officinale Koch. at various phenological stages

Background: The leaves, roots and seeds of Lovage [Levisticum officinale Koch] being used as an herb, vegetable and spice

Objective: The aim of this study is evaluation of the changes of phytochemical compound in aerial parts of the Lovage plants at different developmental stages as well as antioxidant activity

Methods: The plants were harvested from Hezar Mountain. After drying, essential oils were extracted by steam distillation. To identify the essential components GC and GC-MS was used. Antioxidant activity of samples was examined by diphenylpicrylhydrazyl [DPPH] assay

Results: The average yield of essential oil was respectively, 2.3% and 3.1% and 1.5% respectively, in vegetative, Flowering and seed stage. The oil analysis results showed that 21 compounds were identified in the vegetative stage. beta-phellandrene [10.7%] and alpha-Terpinyl acetate [% 38.9] and Curzerene [% 10.6] were the major compound. in the reproductive stage, 22 compounds were identified including beta-phellandrene [20.3%] and alpha-Terpinyl acetate [% 20.4] and gamma-Cadinene [12.1%]. in the seed stage beta-phellandrene [21.1%] and alpha-Terpinyl acetate [%25.3] and Sabinene [10.2%] were the highest. Analysis of variance showed that the effect of harvesting time has significant effect on plant height, stem branch number and yield of oil. The Higher antioxidant power was observed respectively in the flowering stage [83%], vegetative stage [68%] and seed stage [60%]

Conclusion: The phytochemical and antioxidant compounds in Levisticum officinale depend on the phenological stage

[ effect of three different curing methods on the microleakage of Clv posterior composite restorations]

Light-cured composites have become almost universal in modern clinical dentistry. Unfortunately, these materials have demonstrated critical limitations such as postoperative sensitivity and polymerization shrinkage. The aim of this study was to evaluate the effects of three curing modes on the microleakage of class V composite restorations. In this experimental in vitro study, class V cavities were prepared on the buccal surfaces of 90 extracted human molar and premolar teeth and were randomly divided into 3 groups. All teeth were etched followed by bonding and composite filling. Three different methods were used for curing: conventional, 750 mw/cm2/40s; pulse delay, 400 mw/cm2/5s-5 minutes delay-750 mw/cm2/35s; and soft start, beginning at 150 mw/cm2 and increasing to 750 mw/cm2 during 15 seconds and remaining for another 35 seconds. After polishing, the specimens were stored in a 37°C incubator, thermocycled [500 cycles] and immersed in basic%0.5 fushin. Longitudinal buccolingual sections of all teeth were scored for marginal dye penetration under a stereomicroscope. Kruskal-Wallis test was used for statistical analysis. Leakage was observed in all groups but no significant difference was found in the microleakage scores among the three light-curing techniques, used in this investigation. These findings suggest that the 3 studied light-curing methods may have no effect on the microleakage of class V posterior composite restorations

Comparison of microleakage in different methods of restoration in posterior CIv cavities

Despite improvements in the properties of composites, glass ionomers and other tooth colored materials, a number of problems still exist in their clinical application including: post-operative sensitivity, microleakage, technique sensitivity and color change. Different methods have been already presented to recuce microleakage. The aim of this study was to compare the microleakage of different restoration methods in posterior CIV cavities. On the buccal surfaces of 90 extracted human teeth, due to orthodontic treatment, periodotal problem or impaction, CIV cavities with gingival margin on CEJ were prepared. The samples were randomly divided into 5 groups and restored as follows: A: Copalait varnish [Harvard] and amalgam [Cinalux] B: Dentin bonding agent [Exite] and amalgam [Cinalux] C: Dentin bonding agent [Exite] and light cure composite resin [Tetric ceram] D: Resin modified glass ionomer [Fuji II LC] and dentin bonding agent [Exite] and light cure composite resin [Tetric ceram] E: Dentin bonding agent [Exite] and flowable composite [Tetric flow] and light cure composite resin [Tetric ceram]. Restorations were polished, thermocycled in 1600 cycles and immersed in 0.5% basic fushin. Samples were then sectioned and studied under a stereomicroscope to evaluate bye penetration. Data were subjected to Kruskal-Wallis test. All groups showed some degrees of microleakage. According to Kruskal-Wallis statistical analysis, differences between groups were significant [P=0.000000<0.05]. Group C showed the maximum and group D Showed the minimum microleakage. Mann-Whitney analysis was used to compare pairs of groups. Results significant differences between groups as [AD], [C>D], [D