ABSTRACT
Objective:To investigate influencing factors of dental caries among 3 to 5-year-old children in the Yuhua District of Changsha by Cariostat detection and provide evidence to prevent caries.Methods:1 032 children aged 3-5 years old from 6 kindergartens in Yuhua District of Changsha were randomly selected for oral health examination. 565 children in 6 large classes, 6 middle classes and 6 small classes were randomly selected from 6 kindergartens were perfected caries activity test (CAT) by Cariostat detection.Results:Among 1 032 children, 626 had caries, the caries rate was 60.66%, the caries was 2.87±3.67, and the caries filling rate was 8.53%. The caries rate of maxillary central incisors was the highest (37.89%), followed by mandibular second primary molars (32.56%) and mandibular first primary molars (32.36%). There was significant difference in caries rate among different age groups (χ 2=9.231, P<0.05). The caries rate of 5-year-old children was the highest (66.50%). 1 032 children were divided into 4 groups according to dmft (decayed, missing, filled teeth) value, and the number of caries free group was the largest; the number of caries in the middle caries group was the least. The number of missing teeth in 1 032 children with caries was 2 959. The number of missing teeth in the high caries group was the most, up to 1 861, accounting for 61.89% of the total number of missing teeth. The analysis of 565 children by CAT showed that the caries rate was different in different CAT grades (χ 2=27.390, P<0.05). The caries rate in the high-risk group was the highest, 90.48%. The CAT value was positively correlated with caries ( r=0.261, P<0.05). Conclusions:The incidence of dental caries in children aged 3-5 years in Yuhua District of Changsha was 60.66%. Cariostat method can truly reflect the situation of caries in children and is helpful to screen the population susceptible to caries in children.
ABSTRACT
Objective To investigate the effects of adenovirus containing human beta-nerve growth factor (Ad-hNGFβ) gene on substance P (SP) and calcitonin gene-related peptide (CGRP) content of the spinal cord in a rat model of neuropathic pain by chronic constrictive injury (CCI). Methods Forty-eight male SD rats weighing 200-250 g were randomly divided into 3 groups (n=16 each) : group Ⅰ sham operation; group Ⅱ CCI and group Ⅲ CCI + Ad-hNGFβ gene IT. The animals were anesthetized with intraperitoneal choral hydrate 300-350 mg/kg. The right sciatic nerve was exposed and 4 ligatures were placed on the sciatic nerve at 1-2 nun intervals as described by Bennet and Xie[5]. In sham operation group, right sciatic nerve was exposed but not ligated. In group Ⅰ and Ⅱ artificial cerebrnspinal fluid was injected IT instead of Ad-hNGFβ gene. The behavior score and the paw-withdrawal latency (PWL) to radiant heat and mechanical stimulus were measured one day before operation and every 4 days within the 28 days after gene transfection. Four animals were killed at 4, 7, 14 and 28 day after IT gene transfection in each group and lumbar segment (L4-6 ) of the spinal cord was removed for determination of SP and CGRP content by immunohistochemistry. Results The behavior scores were significantly higher and PWL to radiant heat and mechanical stimulus were significantly lower in group Ⅱ and Ⅲ than in group Ⅰ. There was no significant difference in the behavior score and PWL to mechanical stimulus between group Ⅱ and Ⅲ while the PWL to radiant heat was significantly higher in group Ⅲ than in group Ⅱ. After operation SP and CGRP content were significantly higher in group Ⅱ and group Ⅲ than in group Ⅰ , and significangly lower in group Ⅲ than in group Ⅱ 7-28 days after operation. Conclusion The recomhinant Ad-hNGFβ gene transfection can attenuate heat hyperalgesia by reducing SP and CGRP content of the spinal cord in a rat model of neuropathic pain induced by CCI.