The Histopathology Research Of Cinnamaldehyde As Pulp-cap Of Pulpotomy And Root Canal Disinfectant Of Pulpectomy In Rat Teeth

Objective: As the main component of cinnamon which is a kind of naturally occurring drugs, cinnamaldehyde has many pharmacologic actions, such as relieving fever, expanding blood vessel, promoting blood circulation, diaphoresis relieving superficies, evaporation, analgesia, anti-eumycete and anti-tumor, and so on, and meanwhile cinnamaldehyde has low poison and side effect. Anti-anaerobian experiment in-vitro demonstrated that cinnamaldehyde can hindrance the cytoderm formation of 122 strains anaerobian isolated from infected tissues, including 9 genera 22 species common anaerobian, such as bacteroides melanogenicus, caryo-fusobacterium, and peptostreptococcus. Thus cinnamaldehyde affects as anti-anaerobian, as well as anti-aerobe and anti-eumycete. As essential oil, its favorable volatility, penetrability and highly disinfectant sex could be used to as pulp-cap and disinfectant. In order to approach it, we did this animal experiment research by adopting cinnamaldehyde as pulp-cap of pulpotomy and as root canal disinfectant of pulpectomy in rat teeth, and compared with formaldehyde cresol formocresol (FC) and blank. We observed the variation of dental root, pulp tissue of root and periapex after treatment, to investigate the influence of cinnamaldehyde to the pulp tissue and periapex, to provide histopathology basement for exploring cinnamaldehyde as a kind of oral clinical medication.Methods:1. Pulpotomy: 30 Wistar rats were divided into 3 groups randomly, experimental group, control group and blank group, for each 10 rats. After anesthesia, we simulated primary teeth pulpotomy routine. Cinnamaldehyde was used as pulp-cap mixed with zinc oxide in experimental group, while FC equaled clove oil mixed with zinc oxide used in control group, whileblank group with no pulp-cap, and then all carves were filled with glass ion. The animals were killed after 4th and 12th week, experimental teeth and periodontal bone blocks were extracted to make HE slides(4-6μm). Observation by light microscope.2. Pulpectomy: 60 Wistar rats were divided into 3 groups randomly, experimental group, control group and blank group, for each 20 rats. After anesthesia, we simulated primary teeth pulpectomy routine. Cinnamaldehyde was used as root canal disinfectant in experimental group, while FC used in control group, and blank group with no root canal disinfectant, and then all carves were filled with glass ion. The animals were killed after 1st, 2nd, 3rd and 6th week, experimental teeth and periodontal bone blocks were extracted to make HE slides(4-6μm). Observation by light microscope.Results:1. Pulpotomy: 4th week: 20 samples were observed for each group. External resorption of root of tooth, calcification and inflammatory cell infiltration to periapical tissue were not seen in experimental group, and slight internal resorption of root of tooth was seen in 1 tooth. 2 examples of internal resorption, no external resorption, calcification or inflammation were observed in control group. While in blank group, 9 examples of severe internal resorption, and 6 examples of focus form lymphocyte infiltrated in which 3 examples accompanied with external resorption of root tip were observed. Through statistic analysis, internal and external resorption and calcification: there was no difference among 3 groups (P > 0.25); inflammation: no difference between the former two groups (P>0.5), and significance difference from the blank group (P< 0.05). 12th week: 20 samples were observed for each group. Experimental group: 1 sample of external resorption and inflammation, 1 internal resorption and 2 samples of calcification. Control group: no external and internal resorption and no inflammation, 2 samples of calcification. Blank group: 11 samples of severe internal resorption, 15 had inflammation with evident hemangiectasia, in which 4 samples had external resorption. By statistic analysis, internal and external resorption and inflammation: no difference between the former two groups (P>0.5), and significance difference from the blank group (P<0.005); calcification: no difference among all (0.25>P>0.1).2. Pulpectomy: 1st week: inflammation was seen in all slides, while blank group was different from others (P<0.03); hemangiectasia was of no difference among all (P > 0.2); periodontal membrane fiber arranged abnormality and bone resorption were seen in the latter two groups, and of significant difference from the experimental group (P<0.05). 2nd week: inflammation and hemangiectasia of the former two groups were different from blank group (P < 0.01); periodontal membrane fiber arranged abnormality and bone resorption were of no difference among all (P>0.25). 3rd week: inflammation was relieving, and the experimental and control group were different from the other (P < 0.002); hemangiectasia, periodontal membrane fiber arranged abnormality and bone resorption were of no difference among all (P>0.1). 6th week: four indexes were of no difference between the former two, and bone resorption of the blank group was different from the other groups (P<0.02).Conclusions:1. As pulp-cap of pulpotomy, cinnamaldehyde stimulates the pulp at a very low level, which has no difference with FC.2. As root canal disinfectant of pulpectomy, cinnamaldehyde stimulates the periapex at a very low level, and conduce to revive, and has no aggravation to the bone resorption, which has no difference with FC.