Rational design for cooperative recognition of specific nucleobases using ß-cyclodextrin-modified DNAs and fluorescent ligands on DNA and RNA scaffolds.

We propose a binary fluorimetric method for DNA and RNA analysis by the combined use of two probes rationally designed to work cooperatively. One probe is an oligonucleotide (ODN) conjugate bearing a ß-cyclodextrin (ß-CyD). The other probe is a small reporter ligand, which comprises linked molecules of a nucleobase-specific heterocycle and an environment-sensitive fluorophore. The heterocycle of the reporter ligand recognizes a single nucleobase displayed in a gap on the target labeled with the conjugate and, at the same time, the fluorophore moiety forms a luminous inclusion complex with nearby ß-CyD. Three reporter ligands, MNDS (naphthyridine-dansyl linked ligand), MNDB (naphthyridine-DBD), and DPDB (pyridine-DBD), were used for DNA and RNA probing with 3'-end or 5'-end modified ß-CyD-ODN conjugates. For the DNA target, the ß-CyD tethered to the 3'-end of the ODN facing into the gap interacted with the fluorophore sticking out into the major groove of the gap site (MNDS and DPDB). Meanwhile the ß-CyD on the 5'-end of the ODN interacted with the fluorophore in the minor groove (MNDB and DPDB). The results obtained by this study could be a guideline for the design of binary DNA/RNA probe systems based on controlling the proximity of functional molecules.

Adhesion procedures for CAD/CAM indirect resin composite block: A new resin primer versus a conventional silanizing agent.

PURPOSE: The purpose of this study was to evaluate the effectiveness of both a resin primer containing methyl methacrylate (MMA) and a silanizing agent on bonding to indirect resin composite blocks, using two types of build-up hybrid resin composites. METHODS: SHOFU BLOCK HC (Shofu) specimens were blasted with alumina, after which one of two surface treatments was applied: CERA RESIN BOND (Shofu, the Silane group) or HC primer (Shofu, the MMA group). Resin composites made using either Solidex Hardura (SDH, Shofu) or Ceramage Duo (CMD, Shofu) were built up and micro-tensile bond strength (µTBS) values were measured after storage in water for either 24h or 6 months (n=24 per group). The fracture surfaces after µTBS measurements and the resin block/build-up resin interfaces were observed by scanning electron microscopy (SEM). RESULTS: The bond strength of the Silane/SDH group significantly decreased after 6 months (p<0.001), whereas in the MMA group there was no significant loss after 24h or 6 months (p=0.99). In the CMD group, the bond strength after 6 months was significantly lowered in both the Silane group (p<0.001) and the MMA group (p<0.001), but the latter still showed greater adhesion. SEM images demonstrated that the matrix resin was partially destroyed at the fracture surfaces of the MMA group and fracture surface unevenness was observed. CONCLUSIONS: A primer containing MMA produced stronger bonding to CAD/CAM resin even after long-term aging compared to a silane treatment.

MDP is effective for removing residual polycarboxylate temporary cement as an adhesion inhibitor.

The effect of cleaner containing 10-methacryloyloxydecyl dihydrogen phosphate (MDP) for removing temporary cement remnants on dentin surface was evaluated. Flat dentin surfaces were wet-polished (Co) and HY-BOND temporary cement hard (Shofu) was applied to the surface. This temporary cement was removed using an air-scaler (Sc), brush (Br), or phosphoric acid and NaOCl (NC). A prototype cleaner containing MDP (Kuraray Noritake Dental, Tokyo, Japan) was used with agitation mode (MC+AG). KATANA Avencia block (Kuraray Noritake Dental) was luted with SA Cement Plus Automix (Kuraray Noritake Dental). Co showed significantly higher bond strength than Sc or Br (p<0.001 each). Bond strengths with NC (p=0.99) and MC+AG (p=0.38) did not differ significantly from that with Co. Transmission electron microscopy revealed sufficient interaction of MC+AG. Cleaner containing MDP can effectively remove temporary cement by agitation, and can be expected to improve the chemical bonding ability by binding more MDP to dentin.

Cooperative DNA probing using a beta-cyclodextrin-DNA conjugate and a nucleobase-specific fluorescent ligand.

A single nucleotide polymorphism (SNP) base on the target is displayed at a gap in a ternary duplex carrying beta-cyclodextrin-modified DNA. A stable tandem duplex forms regardless of the type of SNP base. A nucleobase-specific ligand is then added to this system. The dansyl moiety in the ligand is expected to form a luminous inclusion complex with nearby beta-CyD, only when the ligand recognizes the specific base displayed in the gap.

Effectiveness of current adhesive systems when bonding to CAD/CAM indirect resin materials: A review of 32 publications.

The purpose of this review was to assess the available literature regarding bonding between current adhesive systems and computer-aided design/computer-aided manufacturing (CAD/CAM) indirect resin materials, to provide clinicians with a comparative overview of the relevant bonding procedures. An electronic search was performed through PubMed based on the keywords CAD/CAM and dental bonding. Additional relevant literature was obtained from the citations in the articles. A total of 313 papers were identified, of which 281 were excluded as being unsuitable, and an additional 3 papers were identified, giving a total of 32 articles that are included in this review. Based on this survey, it is recommended that microretentive surfaces should be generated by either blasting or hydrofluoric acid etching. This initial process should be followed by silanization to ensure chemical adhesion prior to bonding to CAD/CAM indirect resin composite materials (including Lava Ultimet, KATANA AVENCIA block, Gradia Block, Cerasmart, Paradigm, and Block HC) and CAD/CAM polymer-infiltrated ceramics (such as Vita Enamic). The use of materials containing methyl methacrylate (MMA) also appears to improve the bonding of CAD/CAM poly(methyl methacrylate) (PMMA) resin materials (including XHIPC-CAD/CAM, artBloc Temp, and Telio).

Adhesion procedure for CAD/CAM resin crown bonding: Reduction of bond strengths due to artificial saliva contamination.

PURPOSE: The present study aimed to elucidate how saliva contamination affects microtensile bond strength of resin cement to CAD/CAM resin blocks and identify a decontamination method that can restore original bond strength. METHODS: The KATANA AVENCIA block (Kuraray Noritake Dental) was sandblasted on the adherend surface (P-Co group). Then, the block was contaminated with artificial saliva (Saliveht Aerosol, Teijin). Air dry (N-Co), sandblasting (Sb) and phosphate acid cleaning (AT) groups were prepared. After silane treatment, PANAVIA V5 (Kuraray Noritake Dental) was built up and microtensile bond strength (µTBS) was measured after immersion in water (n=24 per group). Scanning electron microscopy (SEM) analysis, surface roughness and contact angle measurement of each surface were performed. RESULTS: The P-Co group showed the highest µTBS value, and bond strength was significantly lower in the N-Co group than the other groups (P<0.001). In all groups, decreased bond strength resulted from long-term water storage. In the N-Co group, a contaminated layer was observed on the surface by SEM and the contact angle was significantly smaller than the other groups (P<0.001). In Sb and AT groups, µTBS values that were reduced by artificial saliva contamination significantly increased but did not recover to P-Co group values (P<0.001). SEM showed no morphological difference between P-Co, Sb and AT groups. The Sb group showed increased surface roughness. CONCLUSION: The long-term durability of bonds between CAD/CAM resin blocks and luting agent cement was significantly reduced by artificial saliva contamination. However, sandblasting or phosphoric acid cleaning can recover bonding effectiveness by 75-85%.

Effects of three drying methods of post space dentin bonding used in a direct resin composite core build-up method.

PURPOSE: The purpose of this study was to evaluate drying methods for post space dentin bonding in a direct resin composite core build-up method. METHODS: Experiment 1: Four root canal plastic models, having diameters of 1.0 or 1.8mm and parallel or tapered shapes, were prepared. After drying each post space using three drying methods (air drying, paper-point drying, or ethanol drying, which involves filling the space with 99.5 vol% ethanol followed by air drying), the residual liquid in the models was weighed. Experiment 2: Thirty endodontically treated single-root teeth were dried using the above-described drying methods and filled with dual-cure resin composite. The bonded specimens were sectioned into square beams of approximately 1mm2 for microtensile bond strength (µTBS) testing. Nine teeth were observed through transmission electron microscopy (TEM) and micro computed tomography (µCT). The weight of residual liquid and µTBS were analyzed using Scheffé multiple comparison. RESULTS: Experiment 1: The results of air drying were significantly different from those of paper-point drying (p<0.001) and ethanol drying (p<0.001), and no significant difference was observed between paper-point drying and ethanol drying. Experiment 2: The µTBS significantly decreased in the order of ethanol drying, paper-point drying, and air drying (air drying/ethanol drying: p<0.001, air drying/paper-point drying: p=0.048, ethanol drying/paper-point drying: p=0.032). TEM and µCT observation revealed a sufficient dentin/adhesive interface in the ethanol drying group. CONCLUSIONS: Ethanol drying was found to be more effective for post space dentin bonding, as compared with air drying and paper-point drying.

Severe Neonatal Hyperbilirubinemia in Crigler-Najjar Syndrome Model Mice Can Be Reversed With Zinc Protoporphyrin.

Neurotoxic bilirubin is solely conjugated by UDP-glucuronosyltransferase (UGT) 1A1. Due to an inadequate function of UGT1A1, human neonates develop mild to severe physiological hyperbilirubinemia. Accumulation of bilirubin in the brain leads to the onset of irreversible brain damage called kernicterus. Breastfeeding is one of the most significant factors that increase the risk of developing kernicterus in infants. Why does the most natural way of feeding increase the risk of brain damage or even death? This question leads to the hypothesis that breast milk-induced neonatal hyperbilirubinemia might bring certain benefits to the body. One of the barriers to answering the above question is the lack of animal models that display mild to severe neonatal hyperbilirubinemia. A mouse model that develops neonatal hyperbilirubinemia was previously developed by a knockout of the Ugt1 locus. Deletion of Ugt1a1 results in neonatal lethality from bilirubin neurotoxicity. Bilirubin is the end product of heme catabolism in which heme oxygenase-I is largely involved. When zinc protoporphyrin, an inhibitor of heme oxygenase I, was administered to newborn Ugt1-/- mice, serum bilirubin levels dropped dramatically, rescuing the mice from bilirubin-induced neonatal lethality. Zinc protoporphyrin-treated Ugt1-/- mice developed normally as adults capable of reproducing, but their newborns showed even more severe hyperbilirubinemia. Microarray analysis of the hyperbilirubinemic livers indicated that a number of genes associated with nucleotide, transport, and immune response were significantly down-regulated in a serum bilirubin level-dependent manner. Conclusion: Our study provides an opportunity to advance the development of effective therapeutics to effectively and rapidly prevent bilirubin-induced toxicity. Neonatal hyperbilirubinemia has various impacts on the body that could be driven by the antioxidant property of bilirubin.

Effectiveness of sodium hypochlorite and sulfinic acid sodium salt treatment on dentin-resin bonding: Long-term durability of one-step self-etching adhesive.

This study aimed to evaluate the effect of sulfinic acid sodium salt interposition after acid and sodium hypochlorite treatment (NC treatment) on dentin bonding durability using a mild type one-step self-etching adhesive. Fifteen human third molars were randomly assigned into three experimental groups according to dentin pretreatment before applying the one-step self-etching adhesive: Cont group, without pretreatment; NC group, pretreatment with phosphoric acid and sodium hypochlorite gel; and NC+AC group, additional treatment with sulfinic acid sodium salt followed by the same pretreatment of the NC group. Microtensile bond strength was measured and the pre-treated dentin surface, fracture modes, and bonding interface were observed. The bond strength of the NC+AC group was significantly higher than that of the other groups (p<0.001). The dentin-adhesive interface was degraded after 1 year only in the Cont group. Our results demonstrated NC treatment improves bonding durability and application of sodium sulfinic acid salt after NC treatment improves bonding effectiveness.