In vitro antibacteriaI effect of benzalkonium chIoride on five common oral pathogens / 中国组织工程研究

BACKGROUND: Benzalkonium chloride has been used in dental restorative materials to enhance the long-lasting antibacterial properties of materials. OBJECTIVE: To evaluate the antibacterial activity of benzalkonium chloride on oral common pathogenic bacteria in vitro. METHODS: The agar diffusion method was used to determine the inhibitory effects of antibacterial agents, 0.1% benzalkonium chloride, 3% H2O2and 5.25% sodium hypochlorite, on five kind of oral pathogens, Porphyromonas gingivalis (P.g), Prevotella intermedia (P.i), Actinobacillus actionmycemcomitans (A.a), Streptococcus mutans (S.m) and Enterococcus faecalis (E.f). The tube dilution method was used to detect the minimal inhibitory concentration of benzalkonium chloride against the five bacteria mentioned above. RESULTS AND CONCLUSION: The antibacterial effect of 0.1% benzalkonium chloride on P.g was not significantly different from that of 3% hydrogen peroxide (P＞0.05), while 0.1% benzalkonium chloride showed better effect on P.i than 3% hydrogen peroxide (P＜0.05). On P.g and P.i, the antibacterial effect of 0.1% benzalkonium chloride was worse than that of 5.25% sodium hypochloritethe ( P＜0.05). The antibacterial effect of 0.1% benzalkonium chloride on A.a and S.m was better than that of 3% hydrogen peroxide (P＜0.05), and similar to that of 5.25% sodium hypochlorite (P＞0.05). The antibacterial effect of 0.1% benzalkonium chloride on E.f was better than that of 3% hydrogen peroxide (P ＜ 0.05), but worse than that of 5.25% sodium hypochlorite (P ＜ 0.05). The minimal inhibitory concentration of benzalkonium chloride to P.g, P.i, A.a, S.m, E.f was 16, 2, 4, 2, 4 mg/L, respectively. To conclude, 0.1% benzalkonium chloride has strong antibacterial effects on P.g, P.i, A.a, S.m and E.f.

Effects of simvastatin gel on bone regeneration in alveolar defects in miniature pigs / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Currently, the most commonly used treatment methods for repairing alveolar furcation defects are periodontal guided tissue regeneration (GTR) and bone grafting. The objective of this study was to investigate the effects of simvastatin/methylcellulose gel on bone regeneration in alveolar defects in miniature pigs.</p><p><b>METHODS</b>Alveolar defects were produced in 32 teeth (the third and fourth premolars) of 4 miniature pigs. The 32 experimental teeth were divided into 5 groups comprising control (C) and treatment (T) teeth: (1) empty defects without gel (group C0, n = 4); (2) defects injected with methylcellulose gel (group C1, n = 4); (3) defects injected with 0.5 mg/50 µl simvastatin/methylcellulose gel (group T1, n = 8); (4) defects injected with 1.5 mg/50 µl simvastatin/methylcellulose gel (group T2, n = 8); and (5) defects injected with 2.2 mg/50 µl simvastatin/methylcellulose gel (group T3, n = 8). Every week after surgery, the furcation sites were injected once with gel. At the eighth week after surgery, the 4 pigs were sacrificed and underwent macroscopic observation, descriptive histologic examination, and regenerate bone quantitative histologic examination.</p><p><b>RESULTS</b>At 8 weeks after surgery, the defect sites in the treatment groups were completely filled in with new bone and fibrous tissue. There was little new bone in the C0 and C1 groups, and only a small number of osteoblasts and proliferative vessels could be seen on microscopic examination.</p><p><b>CONCLUSIONS</b>Miniature pigs are an ideal experimental animal for establishing a model of alveolar defects using a surgical method. Local application of simvastatin/methylcellulose gel can stimulate the regeneration of alveolar bone in furcation defect sites, because it promotes the proliferation of osteoblasts. The best dose of simvastatin gel to stimulate bone regeneration is 0.5 mg.</p>

Prevalence and influencing factors of dental erosion among college students / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the prevalence and influencing factors of dental erosion among college students in Guangzhou and to provide necessary information for the prevention.</p><p><b>METHODS</b>A total of 1704 16-24-year-old students from six colleges or universities were assessed for dental erosion. Data on the social economical status, eating habits, oral hygiene habits, and other related factors were obtained through questionnaire. The influencing factors were analyzed by chi(2)-test and logistic regression analysis.</p><p><b>RESULTS</b>Five hundreds and one of the 1704 subjects suffered from dental erosion (29.4%). The teeth most frequently affected were the upper and lower incisors and first mandibular molar. For tooth surfaces were incisal/occlusal surfaces [66.1% (5491/8311)] and labial/buccal surfaces [31.0% (2574/8311)]. Logistic regression analysis showed that female, those who were not the only child in the family, and students who consumed carbonated drinks more than once per week or drank 500 ml or more of acidic beverages per week were more likely to have dental erosion.</p><p><b>CONCLUSIONS</b>Control of the consuming of acidic beverages is an important measure for the prevention of dental erosion.</p>

A study on oral health behavior and other related factors between children with high dmft and no caries / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To explore the risk factors of children with high dmft.</p><p><b>METHODS</b>In suburban of Guangzhou, oral health of 401 3 - 4-year-old children were examined and structured questionnaire were completed by their parents. 120 children with highest number of dmft (dmft > or = 5) and 118 caries-free children were chosen for case-control analysis.</p><p><b>RESULTS</b>The results of logistic regression analysis showed that the factors associated with high dmft were developmental defect of enamel, visible plaque index, frequency of toothbrushing, frequency of sugar consumption, and income.</p><p><b>CONCLUSIONS</b>Advocating brushing teeth at least twice daily, controlling the frequency of sugar consuming, reducing the developmental defect of enamel and paying more attention to the oral health of lower income population may effectively reduce dental caries of the children.</p>