The comparison of the fluoride uptake and release of a compomer and light-cured glass ionomer cements

Abstract no. 272published_or_final_versio

Supragingival calculus: Formation and control

Dental calculus is composed of inorganic components and organic matrix. Brushite, dicalcium phosphate dihydrate, octacalcium phosphate, hydroxyapatite, and whitlockite form the mineral part of dental calculus. Salivary proteins selectively adsorb on the tooth surface to form an acquired pellicle. It is followed by the adherence of various oral micro-organisms. Fimbriae, flagella, and some other surface proteins are essential for microbial adherence. Microbial co-aggregation and co-adhesion enable some micro-organisms, which are incapable of adhering, to adhere to the pellicle-coated tooth surface. Once organisms attach to the tooth surface, new genes could be expressed so that mature dental plaque can form and biofilm bacteria assume increased resistance to antimicrobial agents. Supersaturation of saliva and plaque fluid with respect to calcium phosphates is the driving force for plaque mineralization. Both salivary flow rate and plaque pH appear to influence the saturation degree of calcium phosphates. Acidic phospholipids and specific proteolipids present in cell membranes play a key role in microbial mineralization. The roles of crystal growth inhibitors, promoters, and organic acids in calculus formation are discussed. Application of biofilm culture systems in plaque mineralization is concisely reviewed. Anti-calculus agents used - centering on triclosan plus polyvinyl methyl ether/maleic acid copolymer, pyrophosphate plus polyvinyl methyl ether/maleic acid copolymer, and zinc ion - in commercial dentifrices are also discussed in this paper.published_or_final_versio

A performance study of packet scheduling algorithms for coordinating colocated Bluetooth and IEEE 802.11b in a Linux machine

Due to the proliferation of hand-held short-range communication devices, coexistence between Bluetooth and IEEE 802.11b has become a performance critical issue. In this study, we performed an actual implementation of a Linux based network access point (NAP), in which Bluetooth and IEEE 802.11b are colocated. Such a NAP is expected to be crucial in supporting 'hot-spot' systems targeted to serve nomadic users carrying either a Bluetooth or a IEEE 802.11b device. Specifically, the goal of our study is to investigate the efficacy of a software based interference coordination approach. We consider five most commonly used scheduling algorithms in a Linux environment. Our extensive experimental results obtained in a real environment indicate that a hierarchical scheduling approach exhibits the best performance in terms of aggregate bandwidth achieved by Bluetooth and IEEE 802.11b.published_or_final_versio

Protection offered by root-surface restorative materials against biofilm challenge

The prevalence of root-surface caries is increasing. We hypothesized that some restorative materials are protective against cariogenic challenge on root surfaces. Our goal was to study the effects of different restorative materials on root surfaces incubated with an oral biofilm generated in an artificial mouth. A biofilm of Streptococcus mutans, Streptococcus sobrinus, Lactobacillus rhamnosus, and Actinomyces naeslundii was co-cultured for 21 days on 24 glass-ionomer cement, resin-modified glassionomer cement, or resin-composite-restored root surfaces. These surfaces were then examined with Fourier transform infrared spectroscopy and scanning electron energy-dispersive spectroscopy. Only glass-ionomer restorations showed a significant increase in log calcium-to-phosphorus ratio (P < 0.01), and a significantly lower log amide I-to-hydrogen phosphate ratio on the root surface after incubation in the artificial mouth. Glass-ionomer restoratives conferred a preventive effect on the root surfaces against initial cariogenic challenge with a mixed-species oral biofilm without therapeutic intervention.published_or_final_versio

Use of Clinpro Cario in diagnosing childhood caries

Abstract no. 0700published_or_final_versio

The first report of Candida dubliniensis from human root caries lesions

published_or_final_versio

The microflora of root surface caries in Southern Chinese

published_or_final_versio

Surface characterization of noncarious cervical sclerotic dentin following treatment with different acidic conditioners

Abstract no. 29published_or_final_versio

Synergistic effect of nogo-neutralizing antibody IN-1 and ciliary neurotrophic factor on axonal regeneration in adult rodent visual systems

The presence of Nogo axon regeneration inhibitory molecules in the central nervous system (CNS) and the counteracting effect of IN-1 antibodies have been widely reported. In this study, we examined the effect of IN-1-producing hybridoma cells on axon regeneration in adult rodent retinal ganglion cells (RGCs) after various types of optic nerve (ON) injury, evaluating therein whether ciliary neurotrophic factor (CNTF) potentiated the effect of IN-1. We found that application of IN-1 alone failed to enhance regeneration of intracranially or intraorbitally transected RGC axons in a peripheral nerve (PN) graft. IN-1 hybridoma cells also failed to significantly promote intraorbitally crushed ON axons to reenter the distal part of the ON. However, a combined application of IN-1 and CNTF had a synergistic effect in both intracranial PN and intraorbital ON crush paradigms. This study suggests that the action of IN-1 antibodies in promoting axon regeneration in the CNS could be more effective when coupled with other appropriate factors.published_or_final_versio

Dental attitudes of patients towards SARS in Hong Kong

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