Removable orthodontic appliances: frequency and cleaning agents used by students and recommended by dentists

Aim: To evaluate the prevalence and hygiene habits of 13-19 years-old adolescent users of removable orthodontic appliances (ROA) and to determine hygiene methods for the appliances prescribed by dentists, in the city of Pelotas. Methods: The study had two stages. The first stage was a telephone interview with dentists. Dentists were interview by telephone calls in order to obtain information regarding the hygiene methods for cleaning acrylic appliances. Second stage was a cross-sectional study performed with schoolchildren. Children from public and private schools with secondary level were included in the sample. A questionnaire was applied to the students using any type of ROA. Questionnaires included demographic information and behavioral characteristics. Data collected were subjected to Chi-square test and logistic regression. Results: The prevalence of children using ROA was 5.4%. Students (89.7%) and dentists (47.2%) reported to prefer mechanical methods to clean their ROA. Cleaning with soup, hydrogen peroxide or effervescent tabs were less used. High frequency of use was associated with higher frequency of hygiene on the ROA. Conclusions: The prevalence of schoolchildren using removable appliances was low. The common cleaning method used by children and prescribed by dentists was mechanical. Hygiene frequency was significantly associated with the routine of use of the appliance and with the type of hygiene method.

Larvicidal, pupicidal and insecticidal activities of Cosmos bipinnatus , Foeniculum vulgare and Tagetes minuta against Culex quinquefasciatus mosquitoes

Purpose: To evaluate the larvicidal, pupicidal and insecticidal activities of Cosmos bipinnatus , Foeniculum vulgare and Tagetes minuta against Culex quinquefasciatus mosquitoes. Methods: The leaves of the plants were extracted with distilled water, ethanol (95 %), and hexane and the extracts screened for their phytochemical profile. While larvicidal and pupicidal activities were assayed at concentrations ranging from 0.1 - 10 mg/mL, insecticidal property was tested at varying amounts (0.25 - 2 g) of the plant sample. The respective larval mortality was thereafter evaluated using Probit analysis. Results: Saponins, terpenoids, flavonoids and steroids were detected in the plant extracts. The ethanol extracts of F. vulgare, T. minuta and C. bipinnatus exhibited larvicidal activity half-maximal lethal concentration (LC50) of 0.10, 1.17 and 1.18 mg/mL, followed by hexane extracts with LC50 value of 1.03, 1.01 and 1.27 mg/mL, respectively, against the larvae of C. quinquefasciatus mosquito. Hexane extracts displayed pupicidal activity with LC50 of 1.07, 1.12 and 1.16 mg/mL against F. vulgare, T. minuta and C. bipinnatus, respectively, while the ethanol extracts of T. minuta, C. bipinnatus and F. vulgare displayed pupicidal activity at LC50 of 1.11, 1.14 and 1.31 mg/mL respectively, against pupa of C. quinquefasciatus mosquito. The aqueous extracts had no (p > 0.05) lethal effects on both larvae and pupa of C. quinquefasciatus at all evaluated concentrations. F. vulgare had the highest (p < 0.05) half-maximal knock-down effect (KD50 = 7.52 min-1), followed by T. minuta (KD50 = 8.64 min-1) on adult C. quinquefasciatus mosquitoes after 6 h of exposure. F. vulgare and T. minuta killed all evaluated mosquito adults within 12 h with LD99 = 0.25 g/air, while the leaves of C. bipinnatus had no (p > 0.05) knock-down or lethal effects on the adult mosquito. Conclusion: C. bipinnatus, F. vulgare and T. minuta possess larvicidal and pupicidal properties against C. quinquefasciatus, whereas only F. vulgare and T. minuta displayed insecticidal properties. Consequent upon these findings, all the plants can be considered naturally potent larvicidal and pupicidal agents against C. quinquefasciatus.

Synthesis and antimicrobial activity of some 2- Piperidinomethylamino-4-(7-H/substituted coumarin-3-yl)- 6-chlorosubstitutedphenyl pyrimidines

Purpose: To prepare and evaluate some 2-piperidinomethylamino-4-(7-H/substitutedcoumarin-3-yl)-6- chlorosubstitutedphenyl pyrimidines as antimicrobial agents. Methods: Some 2-piperidinomethylamino-4-(7-H/substitutedcoumarin-3-yl)-6-chlorosubstitutedphenyl pyrimidines were prepared by reacting 2-amino-4-(7-H/substitutedcoumarin-3-yl)-6- (chlorosubstitutedphenyl) pyrimidines with piperidine and formaldehyde. The chemical structures of the synthesized compounds were elucidated by Fourier transform infrared (FTIR), 1H-nuclear magnetic resonance (1H-NMR), mass spectrometry and elemental analysis. These compounds were investigated for their antimicrobial activity against ten bacteria and five fungi by serial plate dilution method using standard drugs, namely, ofloxacin and ketoconazole, respectively, and their minimum inhibitory concentrations (MICs) were also determined. Results: A total of eighteen new compounds (1a-18a) were synthesized. Compound 6a (MIC = 50 μg/mL; p < 0.05 or less) displayed the highest activity against S. aureus , E. faecalis , Staphylococcus epidermidis , B. subtilis , and B. cereus . Compound 6a further showed good activity (MIC = 25 μg/mL; p < 0.05 or less) against E. coli ; P. aeruginosa K. pneumonia , B. bronchiseptica , and P. vulgaris . Compounds 6a (MIC = 25 μg/mL; p < 0.0001) and 17a (MIC = 25 μg/mL; p < 0.0001) displayed very good activity against C. albicans , A. niger , A. flavus , M. purpureous , and P. citrinum , respectively. Analysis of structure-activity relationship revealed that the presence of bromo group at 7-postion of the coumarin moiety along with the 4-chlorophenyl group at position-6 of the pyrimidine ring is critical for antimicrobial activity against Gram-positive bacteria, Gram negative bacteria and fungi. Conclusion: The synthesized 2-piperidino derivatives are better antifungal and antibacterial agents than the earlier reported 2-morpholino derivatives, but require further investigations against other microbial strains to ascertain their broad spectrum antimicrobial activity.