PURPOSE: Porcelain fused to metal (PFM) crowns provide the best treatment option for teeth that have a large or defective restoration. More than 20% of teeth with PFM crowns or bridges require non-surgical root canal treatment (NSRCT). This may be due to the effect of restorative procedures and the possible leakage of bacteria and or their by-products, which leads to the demise of the tooth pulp. Thus, this study was planned to compare the ability of the restorative materials to seal perforated PFM specimens. MATERIALS AND METHODS: The study evaluates the ability of amalgam, composite or compomer restorative materials to close perforated PFM specimen's in-vitro. Ninety PFM specimens were constructed using Ni-Cr alloys and feldspathic porcelain, and then they were divided into 3 groups: amalgam (A), composite + Exite adhesive bond (B) and compomer + Syntac adhesive bond (C). All the PFM samples were embedded in an acrylic block to provide complete sealing of the hole from the bottom side. After the aging period, each group was further divided into 3 equal subgroups according to the thermocycling period (one week for 70 cycles, one month for 300 cycles and three months for 900 cycles). Each subgroup was put into containers containing dye (Pelikan INK), one maintained at 5degrees C and the other at 55degrees C, each cycle for 30 sec time. The data obtained was analyzed by SPSS, 2006 using one way ANOVA test and student t-test and significant difference level at (P<.01). RESULTS: The depth of dye penetration was measured at the interfaces of PFM and filling materials using Co-ordinate Vernier Microscope. The lowest levels of the dye penetration for the three groups, as well as subgroups were during the first week. The values of dye leakage had significantly increased by time intervals in subgroups A and C. CONCLUSION: It was seen that amalgam showed higher leakage than composite while compomer showed the lowest level of leakage.
Adhesives ; Aging ; Alloys ; Bacteria ; Crowns ; Dental Porcelain ; Dental Pulp Cavity ; Humans ; Tooth

Two new dimeric naphthoquinones, 5',8'-dihydroxy-6,6'-dimethyl-7,3'-binaphthyl-1,4,1',4'-tetraone (1; Di-naphthodiospyrol D) and 5',8'-dihydroxy-5,8-dimethoxy-6,6'-dimethyl-7,3'-binaphthyl-1,4,1',4'-tetraone (2; Di-naphthodiospyrol E), along with known naphthoquinones diospyrin (3) and 8-hydroxy diospyrin (4) were isolated from the chloroform fraction of extract of Diospyros lotus roots. Their structures were elucidated by advanced spectroscopic analyses, including HSQC, HMBC, NOESY, and J-resolved NMR experiments. The fractions and compounds 1-4 were evaluated for urease activity and phosphodiesterase-I, carbonic anhydrase-II and α-chymotrypsin enzyme inhibitory activities. Compounds 1 and 2 and their corresponding fractions showed significant and selective inhibitory effects on urease activities. The IC values of 1 and 2 were 260.4 ± 6.37 and 381.4 ± 4.80 µmol·L, respectively, using thiourea (IC = 21 ± 0.11 µmol·L) as the standard inhibitor. This was the first report demonstrating that the naphthoquinones class showed urease inhibition.
Biological Assay ; Diospyros ; chemistry ; Enzyme Inhibitors ; chemistry ; isolation & purification ; pharmacology ; Molecular Structure ; Naphthoquinones ; chemistry ; isolation & purification ; pharmacology ; Plant Extracts ; chemistry ; pharmacology ; Plant Roots ; Urease ; antagonists & inhibitors

TRPA1 channels are non-selective cation channels that could be activated by plant-derived pungent products, including gingerol, a main active constituent of ginger. Ginger could improve the digestive function; however whether ginger improves the digestive function through activating TRPA1 receptor in gastrointestinal tract has not been investigated. In the present study, gingerol was used to stimulate cell lines (RIN14B or STC-1) while depletion of extracellular calcium. TRPA1 inhibitor (rethenium red) and TRPA1 gene silencing via TRPA1-specific siRNA were also used for mechanistic studies. The intracellular calcium and secretion of serotonin or cholecystokinin were measured by fura-2/AM and ELISA. Stimulation of those cells with gingerol increased intracellular calcium levels and the serotonin or cholecystokinin secretion. The gingerol-induced intracellular calcium increase and secretion (serotonin or cholecystokinin) release were completely blocked by ruthenium red, EGTA, and TRPA1-specific siRNA. In summary, our results suggested that gingerol derived from ginger might improve the digestive function through secretion releasing from endocrine cells of the gut by inducing TRPA1-mediated calcium influx.
Calcium ; metabolism ; Calcium Channels ; genetics ; metabolism ; Catechols ; pharmacology ; Cell Line ; Fatty Alcohols ; pharmacology ; Gastrointestinal Tract ; drug effects ; metabolism ; Ginger ; chemistry ; Humans ; Nerve Tissue Proteins ; genetics ; metabolism ; Plant Extracts ; pharmacology ; TRPA1 Cation Channel ; Transient Receptor Potential Channels ; genetics ; metabolism