| Objective: Bacterial residual is an important reason for the failure of root canal therapy, and Enterococcus faecalis is the main residual bacteria after the root canal therapy, so to inhibit it will directly affect the long-term efficacy in root canal therapy. Enterococcus faecalis (E. faecalis) belongs to the body's normal flora, and is an important human pathogens of opportunistic infections, often inhibits in human intestinal tract, vagina and oral cavity, which is Gram-positive facultative anaerobes. Enterococcus faecalis,which hidden in the root canal isthmus, bifurcation area, triangle, shape and irregular dentinal tubules, is removed difficultly to only by mechanical means , it can tolerant harsh ecological environment by the mechanisms of biofilm, proton pump in the root canals to avoid conventional drugs, so lead to the failure of root canal therapy. Chinese Cinnamaldehyde is the main component of volatile oil (cinnamon oil) which was obtained by steam distillation from dry skin and cinnamon bark of lauraceae plants. It has been researched as a root canal sterilization drug in recent years, it can seriously undermine the bacterial cell surface structure, and thus has a wider antibacterial spectrum and strong antibacterial activity. gallnut hundred, also known as worms, is a kind of gall that be formatted by Schlechtendalia species of insects including Schlechtendalia and times aphid eggs in their parasitic plants Anacardiaceae Rhus chinensis, Green bran Yang or red bran Yang, the main ingredient is gallnut tannin, can solidify microbial protoplasts and inhibit a variety of body enzymes, a wide range of bacteria, fungi, yeasts. These two traditional Chinese medicine has a strong antibacterial activity, and more importantly, they have an advantage that lower toxicity than traditional disinfectant drug - Formocresol, CP. In order to help to develop a new strategies to prevent or eliminate the infection of E. faecalis, to improve treatment results in endodontics and give a reference to clinical application. In present research, we investigated the antimicrobial activity of Chinese herbs cinnamic aldehgd and Chinese gallnut against E. faecalis in root canals in vitro, using traditional Drug formocresol (FC) and the current most respected calcium hydroxide (calcium hydroxide mixed with propylene glycol) as the conventional controlMethods: 84 freshly extracted , single-rooted premolars were randomly divided into two experimental groups (cinnamic aldehyde and gallnut decoction group) and four control group (FC group, calcium hydroxide mixed with propylene glycol group, negative the control group and positive control group). There was 14 specimens in each group. The teeth were immersed in 5.25% Naclo solution for 24h, then prepare the root canal to 40# with step-back technique. Alternately flush the teech with 5.25% Naclo solution and 17% EDTA solution, then wash them with ultrasonic plaster. The crowns and apices of the teeth were resected to produce uniform 6-mm-long specimens with high-speed diamond bur. All roots were put into BHI ,then incubated at 37℃(5%CO2).24h later, through the observation to turbidity of BHI to make sure the complete sterilization. Recovered and identificated Enterococcus faecalis,and inoculated in BHI, then adjust turbidity into 0.5M with turbidimetry. All the specimens were infected with E. faecalis, except the negative control group. The medicaments were injected into the canals of experimental groups. Then they were incubated at 37℃(5%CO2), but the canals of positive control group were filled with physiological saline. After 3 and 7 days, seven specimens were taken out from each group, uniformly get dentine powder for 4mg from the inner layer of root with G drilling and electronic balance. Place the dentine powder into the small bottles containned with 20ml BHI. Then they were incubated at 37℃(5%CO2) for 72h, then get the upper liquid and measured the turbidity of bacteria by turbidimetry. At the same time, take a little of the upper liquid of each group separately and inoculated them onto blood agar medium. After 48h, bacteria species were identified by microscopy.Results: 1. when the dentin chips were cultured 3 days, the residual quantity of bacteria were less in cinnamic aldehyde group, FC control group and calcium hydroxide mixed with propylene glycol group than in the positive control group (P <0.05), and had no difference with the negative control group (P> 0.05); the residual quantity of bacteria were less than in gallnut decoction group than the positive control group(P <0.05), but more than the negative control group(P <0.05).2. when the dentin chips were cultured 7 days, there were no bacteria observed in cinnamic aldehyde group, gallnut decoction group, FC group and calcium hydroxide mixed with propylene glycol group , there were no difference with the negative control group (P> 0.05).Conclusion: 1. When the dentin chips were cultured 3 days, cinnamaldehyde group had been able to kill Enterococcus faecalis, it had bactericidal effect as the same as FC group or Calcium hydroxide mixed with propylene glycol group.2. Gallnut decoction group was effective on inhibiting Enterococcus faecalis when the dentin chips were cultured 3 days; when the dentin chips were cultured 7 days, Enterococcus faecalis was successfully killed, although not as quickly as the other three drug groups.
|
PDF Full Text Request