The Preliminary Study Of The Aqueous Extract Of Chinese Gallnut For Root Canal Disinfection

Although most of the bacteria, necrotized pulp and infected dentin are removed from the root canals after chemical and mechanical preparation, there still have etiological agents such as residual bacteria ,endotoxin in collateral pulp canals ,deep part of dentinal tubules and periapex. Therefore, root canal disinfection is required to eliminate remaining bacteria that may survive inside root canals after complete chemomechanical preparation.Root canal disinfection should be neither neglected nor overemphasized. The recognization about the role of that has been changed after long-term studies in clinical and experimental process. Objective and reasonable viewpoints have been formed.Measures should be taken to evaluate the effect of root canal disinfection for different methods and medicants. The most popular method clinically used for root canal disinfection is root canal dressing.Chinese gallnut contains tannic acid abundantly. It has favourable antibacterial activities and styptic effect, which have been justified by former studies. So gallnut probably can be used as root canal dressing for root canal disinfection. The aim of this study is to evaluate its antibacterial activities of the on anaerobic strains from the infected root canals both in vitro and in vivo , its influence on the inflammation of periapical disease and its influence on root canal dentinal tubules, so as to discuss the applying prospect of gallnut for rootcanal disinfection.l.In vitro study of the antibacterial activities of the aqueous extract ofChinese gallnut on anaerobic strains from the infected root canalsThe antibacterial activities of the aqueous extract of Chinese gallnut on both facultative aerobes-anaerobes and obligate anaerobic strains from the infected root canals was evaluated. The bacteria used were: Peptostreptococcus anaerobius ATCC27337, Prevotella intermedia ATCC25611, Fusobacterium nucleatumATCC25586, Actinomyces naeslundii ATCC12104, Staphylococcus aureus, ATCC25923, Escherichia coli ATCC25922.The study was carried out by using a broth dilution technique in vitro.The results were presented as values of minimal inhibitory and bactericidal concentrations (MIC and MBC). Calcium hydroxide was used as a control. The aqueous extract of Chinese gallnut showed antibacterial activity against all bacteria used. MIC and MBC values varied according to the bacteria employed. While calcium hydoxide was not effective in inhibiting the growth of the three facultative aerobes-anaerobes strains within all concentrations. Results showed that Chinese nugall had a bactericidal effect on both facultative aerobes-anaerobes and obligate anaerobic strains and it may be used for the medication of root canal.2. In vivo study of the aqueous extract of Chinese gallnut used as an intracanal medicantThe animal model of infected root canal was made to evaluate the antibacterial activities on anaerobic strains in the root canals. HE slice was also made to evaluate the influence on the inflammation of periapical disease among four different groups. The data were analysed by using the nonparametric test. The results showed that comparing with control group, Fc, Ca(OH)2 paste, gallnut paste all have antibacterial activities on anaerobic strains in vivo They all can reduce the amount of anaerobic strains in root canals after preparation. Gallnut paste can also alleviate the inflammation of periapical disease to some extent,which may be related to its styptic effect.3. The influence of the aqueous extract of Chinese gallnut on root canal...