| The special properties of artificial teeth materials like species, peculiarity and surface character as well as the different methods of prosthodontics, which can change the oral environment, have intimate relations with growth, proliferation, setting of pathogenic bacterium after the absence of teeth or dentitions. And the denture stomatitis, secondary dental caries, gingivitis and paradentosis resulted from pathogenic bacterium are always the concerned problems clinically. To lessen the bacterial plaque adhesion on the surface of denture and to prevent the secondary dental caries, denture stomatitis and paradentosis after wearing artifical teeth, the methods such as mechanical cleaning, chemical soaking and organic antimicrobial adding are adopted in clinical. However, the treatments mentioned above have the disadvantages including destroying the surface morphology of plate, shorter antibiosis time, inferior heat resistance and tedious handling, so they are far from the clinical demands.Nanometer silver base inorganic antimicrobial agent (NSBIAA) has generally been the focal point in the field of antibiosis materials both at home and abroad by reason of many advantages, for instance wider antibacterial spectrum, longer antibiosis efficacy, better thermal stability, lower bacterial drug resistance incidence and biocompatibility, with which it may be one of the potential candidates of dentistry antibiosis materials. There have been considerable studies in understanding the effects of NSBIAA on antibiosis improvement of resin splicing agent and soft lining materials, and the sterilizing actions on many types of oral facultative or obligate anaerobes have been demonstrated to be efficiency. Nevertheless, applications of NSBIAA in denture base resin and ceramic glaze have never been reported so far, not to speak of the related oral rehabilitation materials.For the purposes of exploring the feasibility of NSBIAA as the oral rehabilitation materials, developing the denture base resin and ceramic glaze with self-antibiosis properties and preventing the secondary dental diseases after wearing artifical teeth, five brands of NSBIAA are compared according to the examinations, including minimal bactericidal concentrations (MBC) to oral pathogenic bacterium, cytotoxicity in vitro and haemolysis activity in the present study. Similarly, the comparisons above are also the principle of electing suitable NSBIAA. In this study, the denture base resin and ceramic glaze with self-antibiosis properties are testified with various experiments, including the aspects of antibacterial agent reshaping, adding technology, incorporation ratio of NSBIAA, antibiosis efficacy evaluation, Ag release efficiency, antibiosis effectiveness time, observation of clinical cases and so on, for the sake of offering the foundation of clinical applications in future.The main experimental results are as follows:Biocompatibility and antibiosis efficacy evaluations─The results of cell toxicity tests reveal the cytotoxicity are decreasing gradually with the concentration degression of all five types of NSBIAA. The concentration of 50mg/mL or lower than 50mg/mL has been found to be safe to mouse fibroblasts. The comparisons among the products show that Novaron and Conval-PAg40 have lower cytotoxicity than the other three types.─The negative results of hemolysis tests demonstrated Novaron and Conval-PAg40 would never bring out hemolytic crisis.─The antibiosis tests display the significant sterilizing efficacy on oral pathogenic bacterium of all five types of NSBIAA. The products are arrayed below according to their effects from higher to lower: Conval-PAg40, Novaron, HN-300, XDK-101 and Zeomic. Among these ones, Conval-PAg40 might be the main role of the future experiments for its lowest MBC of 0.531mg/mL.Study on antibacterial denture base resin─NSBIAA transforms the hydrophilia surface into lipophilicity surface after organ-reshaping with octadecanoic acid/titanic acid-oate coupling agent, which might not influence the antibiosis efficacy, and dispersed well in PMMA matrix.─The NSBIAA incorporated antibacterial denture base resin reveal the powerful bactericidal effects on candida albicans, streptococcus mutans and staphylococcus aureus, and sterilization ratio increases drastically with the incorporation ratio of NSBIAA. The suggested incorporation ratio of clinical applications is 2.5%.─Considering the incorporation of NSBIAA lower the mechanical function of PMMA denture base resin, the incorporation ratio of NSBIAA should be controlled in the range of 2-2.5% in our study. Here the mechanical function of denture base resin with NSBIAA are better than that of control one and strengthened, which can satisfy the clinical demand for strength.─Color variation of antibacterial denture base resin show the positive correlation with the incorporation ratio of NSBIAA, but lower dose might not result in the obvious variation instead of better aging-resistant and constancy. In our opinion, the incorporation ratio of NSBIAA should be lower than 3% due to aesthetics feelings and the relevant color variation may be accepted in clinical.─The results of 12-month natural aging and 3-month accelerating aging tests demonstrate the sterilizing rate of antibacterial denture base resin are higher than 90%, which in accord with the fact that the products had sterilizing efficacy, and the remaining periods of bacteriostasis are no less than 2 years. The properties of prolonged action fit the fundamental need and the products have the clinical feasibility.─The common denture base resin show the positive properties of reducing bacterial amount on surface and restraining the forming of candida albicans mycoderm with the incorporation of NSBIAA.─Specially, the antibacterial complete denture base resin display the distinguished inhibiting effects on bacterial amounts on surface and adhesion and proliferation of candida albicans.Study on antibacterial ceramic glaze─NSBIAA is dispersing well in ceramic glaze with the mixture of pebble mill, and suitable incorporation might lower the consistency and enhance the suspension stability of ceramic glaze serum and accordingly improve the quality of glaze. Whereas, excess incorporation might result in granules agglomeration in the ceramic glaze serum and demolish the stability, so that influence the quality and color of glaze. From the considerations mentioned above, the suggested incorporation is 4wt%～6wt%in this study.─The NSBIAA incorporated antibacterial ceramic glaze reveal the inhibiting effects on streptococcus mutans, streptococcus sanguis and porphyromonas gingivalis growth on surface, and antibacterial effects show the positive correlation with the incorporation ratio of NSBIAA. At the additive amount of 4%, the antibacterial effective rates on the three pathogenic bacterium are near to or beyond 90%, and the rates are all beyond 99% at the condition of 6% addition. However, repeating agglutination will lower the antibacterial efficacy of antibacterial ceramic glaze, even on occasion of less addition. As a result, antibacterial ceramic teeth are required to reglazing in case of agglutinating again after complement for the sake of remaining the antibacterial efficacy of antibacterial ceramic glaze.─Luminosity L* of antibacterial ceramic glaze reflects the degraded tendency along with enhancive NSBIAA, while chromaticity a* and b* show no significant difference with the increase of NSBIAA addition. Chromatic aberration△E exhibits the positive correlation with the incorporation ratio of NSBIAA. When the additive amount is higher than 6%, color differences between experimental and control groups are obvious; so the suggested additive amount are 4% (anterior teeth lip side ceramic glaze), 5%(morsal teeth bucco-ceramic glaze), 6%( anterior teeth and morsal teeth lingua side ceramic glaze, morsal adjacent teeth masticating surfaces and bridge pontic tissue surfaces). The aging resistance of antibacterial ceramic glaze incorporating NSBIAA is also excellent to satisfy the clinical demands.─The common ceramic glaze shows the positive properties of reducing bacterial amount on surface and restraining the forming of streptococcus mutans mycoderm with the incorporation of NSBIAA. antibacterial efficacy and biocompatibility. Antibacterial denture base resin and antibacterial ceramic glaze with the incorporation of NSBIAA show the properties of permanent restraining bacterium and eumycete growing on surface and the feasibility of clinical application. In our study, the suggested incorporation ratio of NSBIAA into antibacterial denture base resin is 2.5%. The suggested incorporation ratios of NSBIAA into antibacterial ceramic glaze according to different positions are as follows: 4% (anterior teeth lip side), 5% (morsal teeth bucco-ceramic glaze), 6%( anterior teeth and morsal teeth lingua side ceramic glaze, morsal adjacent teeth masticating surfaces and bridge pontic tissue surfaces).
|
PDF Full Text Request