Effect of saccharin on antibacterial activity of chlorhexidine gel

Although chlorhexidine is the most effective agent against dental plaque it is extremely bitter. To prepare formulations, it is necessary to use flavoring and sweetening, which can inhibit the antibacterial effect of chlorhexidine. Saccharin has been considered a compatible substance to use in chlorhexidine rinse or gel preparations; however, the effect of a range of concentrations has not been studied. To evaluate the effect of different concentrations of saccharin on the antibacterial activity of chlorhexidine gel, hydroxy-ethyl-cellulose gels containing 1.0% chlorhexidine digluconate and 0.0 to 1.0% sodium saccharin were prepared. Activity against Streptococcus mutans was evaluated using the agar diffusion method and determination of MIC values. The inhibitory zones of growth were 7.83 +/- 0.54 mm when no saccharin was added to the chlorhexidine gel and 7.75 +/- 0.50, 7.63 +/- 0.48, 6.21 +/- 0.40, 4.13 +/- 0.38, when the concentrations of saccharin in the gels were 0.02, 0.10, 0.5, and 1.0%, respectively. The range of MIC values was 1-2 micrograms/ml, with saccharin concentrations of 0%, 0.02, and 0.1%. In contrast, the MIC values were 4-8 and 8-16 micrograms/ml with saccharin concentrations of 0.5% and 1.0%, respectively. The paired "t" test showed that 0.5 and 1.0% sodium saccharin inhibit the antibacterial activity of 1% digluconate chlorhexidine gel. These in vitro results suggest that saccharin may inhibit the efficacy of chlorhexidine against mutans streptococci, depending on the concentration.Although chlorhexidine is the most effective agent against dental plaque it is extremely bitter. To prepare formulations, it is necessary to use flavoring and sweetening, which can inhibit the antibacterial effect of chlorhexidine. Saccharin has been considered a compatible substance to use in chlorhexidine rinse or gel preparations; however, the effect of a range of concentrations has not been studied. To evaluate the effect of different concentrations of saccharin on the antibacterial activity of chlorhexidine gel, hydroxy-ethyl-cellulose gels containing 1.0% chlorhexidine digluconate and 0.0 to 1.0% sodium saccharin were prepared. Activity against Streptococcus mutans was evaluated using the agar diffusion method and determination of MIC values. The inhibitory zones of growth were 7.83 +/- 0.54 mm when no saccharin was added to the chlorhexidine gel and 7.75 +/- 0.50, 7.63 +/- 0.48, 6.21 +/- 0.40, 4.13 +/- 0.38, when the concentrations of saccharin in the gels were 0.02, 0.10, 0.5, and 1.0%, respectively. The range of MIC values was 1-2 micrograms/ml, with saccharin concentrations of 0%, 0.02, and 0.1%. In contrast, the MIC values were 4-8 and 8-16 micrograms/ml with saccharin concentrations of 0.5% and 1.0%, respectively. The paired "t" test showed that 0.5 and 1.0% sodium saccharin inhibit the antibacterial activity of 1% digluconate chlorhexidine gel. These in vitro results suggest that saccharin may inhibit the efficacy of chlorhexidine against mutans streptococci, depending on the concentration1112934Embora clorexidina seja reconhecida como o agente antimicrobiano mais eficiente contra placa dental, seu gosto extremamente amargo é uma limitação nos preparos farmacêuticos. Substâncias adoçantes e flavorizantes usadas para preparar formulações podem inibir a atividade antibacteriana da clorexidina. Sacarina tem sido considerada uma substância compatível para ser usada em enxaguatórios bucais ou géis, entretanto o efeito da concentração deste adoçante não tem sido estudado. A atividade antibacteriana de géis de clorexidina a 1%, contendo sacarina de 0,0 a 1,0%, foi avaliada a partir de preparações farmacêuticas formuladas. Atividade contra Streptococcus mutans foi avaliada através da inibição do crescimento em ágar e determinação da concentração inibitória mínima (CIM). Os halos de inibição de crescimento foram de 7,83 ± 0,54 mm, na ausência de sacarina, e de 7,75 ± 0,50, 7,63 ± 0,48, 6,21 ± 0,40 e 4,13 ± 0,38 quando da presença de sacarina a 0,02, 0,10, 0,5 e 1%, respectivamente, nos géis de clorexidina a 1%. A faixa de CIM foi de 1-2 µg/ml quando da presença de 0,0, 0,02 e 0,1% de sacarina nos géis. Quando o gel de clorexidina a 1% continha sacarina a 0,5 e 1% a CIM foi de 4-8 e 8-16 µg/ml, respectivamente. Teste "t" pareado mostrou que sacarina sódica nas concentrações de 0,5 e 1% inibiu a atividade anti mutans de digluconato de clorexidina a 1% em gel. Estes resultados in vitro sugerem que sacarina pode inibir a eficácia de clorexidina contra streptococcus do grupo mutans, dependendo da concentração usad

Evidence-based recommendation on toothpaste use

Toothpaste can be used as a vehicle for substances to improve the oral health of individuals and populations. Therefore, it should be recommended based on the best scientific evidence available, and not on the opinion of authorities or specialists. Fluoride is the most important therapeutic substance used in toothpastes, adding to the effect of mechanical toothbrushing on dental caries control. The use of fluoride toothpaste to reduce caries in children and adults is strongly based on evidence, and is dependent on the concentration (minimum of 1000 ppm F) and frequency of fluoride toothpaste use (2×/day or higher). The risk of dental fluorosis due to toothpaste ingestion by children has been overestimated, since there is no evidence that: 1) fluoride toothpaste use should be postponed until the age of 3-4 or older, 2) low-fluoride toothpaste avoids fluorosis and 3) fluorosis has a detrimental effect on the quality of life of individuals exposed to fluoridated water and toothpaste. Among other therapeutic substances used in toothpastes, there is evidence that triclosan/copolymer reduce dental biofilm, gingivitis, periodontitis, calculus and halitosis, and that toothpastes containing stannous fluoride reduce biofilm and gingivitis.Toothpaste can be used as a vehicle for substances to improve the oral health of individuals and populations. Therefore, it should be recommended based on the best scientific evidence available, and not on the opinion of authorities or specialists. Fluoride is the most important therapeutic substance used in toothpastes, adding to the effect of mechanical toothbrushing on dental caries control. The use of fluoride toothpaste to reduce caries in children and adults is strongly based on evidence, and is dependent on the concentration (minimum of 1000 ppm F) and frequency of fluoride toothpaste use (2×/day or higher). The risk of dental fluorosis due to toothpaste ingestion by children has been overestimated, since there is no evidence that: 1) fluoride toothpaste use should be postponed until the age of 3-4 or older, 2) low-fluoride toothpaste avoids fluorosis and 3) fluorosis has a detrimental effect on the quality of life of individuals exposed to fluoridated water and toothpaste. Among other therapeutic substances used in toothpastes, there is evidence that triclosan/copolymer reduce dental biofilm, gingivitis, periodontitis, calculus and halitosis, and that toothpastes containing stannous fluoride reduce biofilm and gingivitis28111

Black-Hole Mass and Growth Rate at High Redshift

We present new H and K bands spectroscopy of 15 high luminosity active galactic nuclei (AGNs) at redshifts 2.3-3.4 obtained on Gemini South. We combined the data with spectra of additional 29 high-luminosity sources to obtain a sample with 10^{45.2}<\lambda L_{\lambda}(5100A)<10^{47.3} ergs/sec and black hole (BH) mass range, using reverberation mapping relationships based on the H_beta method, of 10^{8.8}-10^{10.7} M_sun. We do not find a correlation of L/L_Edd with M_BH but find a correlation with \lambda L_{\lambda}(5100A) which might be due to selection effects. The L/L_Edd distribution is broad and covers the range ~0.07-1.6, similar to what is observed in lower redshift, lower luminosity AGNs. We suggest that this consistently measured and calibrated sample gives the best representation of L/L_Edd at those redshifts and note potential discrepancies with recent theoretical and observational studies. The lower accretion rates are not in accord with growth scenarios for BHs at such redshifts and the growth times of many of the sources are longer than the age of the universe at the corresponding epochs. This suggests earlier episodes of faster growth at z>~3 for those sources. The use of the C IV method gives considerably different results and a larger scatter; this method seems to be a poor M_BH and L/L_Edd estimator at very high luminosity.Comment: 8 pages (emulateapj), 4 figures. Accepted for publication in Ap

Generalised verification of the observer property in discrete event systems

The observer property is an important condition to be satisfied by abstractions of Discrete Event Systems (DES) models. This paper presents a generalised version of a previous algorithm which tests if an abstraction of a DES obtained through natural projection has the observer property. The procedure called OP-verifier II overcomes the limitations of the previously proposed verifier while keeping its computational complexity. Results are illustrated by a case study of a transfer line system

Generalised verification of the observer property in discrete event systems

The observer property is an important condition to be satisfied by abstractions of Discrete Event Systems (DES) models. This paper presents a generalised version of a previous algorithm which tests if an abstraction of a DES obtained through natural projection has the observer property. The procedure called OP-verifier II overcomes the limitations of the previously proposed verifier while keeping its computational complexity. Results are illustrated by a case study of a transfer line system

Verification of the observer property in discrete event systems

The observer property is an important condition to be satisfied by abstractions of Discrete Event System (DES) models. This technical note presents a new algorithm that tests if an abstraction of a DES obtained through natural projection has the observer property. The procedure, called OP-Verifier, can be applied to (potentially nondeterministic) automata, with no restriction on the existence of cycles of 'non-relevant' events. This procedure has quadratic complexity in the number of states. The performance of the algorithm is illustrated by a set of experiments

Prevalence Of Bruxism And Emotional Stress And The Association Between Them In Brazilian Police Officers

This study aimed to assess the prevalence of bruxism and emotional stress in Brazilian police officers, due to exposure to stressful situations, and to assess the relationship between the type of work done by a police officer and the presence of bruxism and emotional stress. A cross-sectional study was conducted at the Military Police of the State of São Paulo, Campinas, SP, Brazil. The final sample included 394 male police officers (mean age = 35.5 years). Bruxism was diagnosed by the presence of aligned dental wear facets associated with the presence of one of the following signs or symptoms: self-report of tooth-grinding, painful sensitivity of the masseter and temporal muscles, discomfort in the jaw musculature upon waking. The Stress Symptoms Inventory (SSI) was applied to evaluate emotional stress. The type of work done by the police was classified as organizational or operational, the latter being assumed as the more stressful since it exposes the police officer to life risk. The results showed a prevalence of bruxism of 50.2% and a prevalence of emotional stress of 45.7%. The Chi-square test indicated an association between stress and bruxism (P < .05). No significant association was found between emotional stress and type of work (P = .382) or between bruxism and work activity (P = .611). It could be concluded that emotional stress was associated with bruxism, independently of the type of work done by police officers.2213135Lavigne, G.J., Rompré, P.H., Montplaisir, J.Y., Sleep bruxism: Validity of clinical research diagnostic criteria in a controlled polysomnographic study (1996) J Dent Res, 75 (1), pp. 546-552Lobbezoo, F., Naeije, M., Bruxism is mainly regulated centrally, not peripherally (2001) J Oral Rehabil, 28 (12), pp. 1085-1091Arnold, A., Bruxism and the occlusion (1981) Dent Clin North Am, 25, pp. 395-407Rugh, J.D., Harlan, J., Nocturnal bruxism and temporoman-dibular disorders (1988) Adv Neurol, 49, pp. 329-341Tsai, C.M., Chou, S.L., Gale, E.N., McCall Jr, W.D., Human masticatory muscle activity and jaw position under experimental stress (2002) J Oral Rehabil, 29 (1), pp. 44-51Manfredini, D., Landi, N., Romagnoli, M., Bosco, M., Psychic and occlusal factors in bruxers (2004) Aust Dent J, 49 (2), pp. 84-89Pingitore, G., Chrobak, V., Petrie, J., The social and psychologic factors of bruxism (1991) J Prosthet Dent, 65 (3), pp. 443-446Watanabe, T., Ichikawa, K., Clark, G.T., Bruxism levels and daily behaviors: 3 weeks of measurement and correlation (2003) J Orofac Pain, 17 (1), pp. 65-73Pierce, C.J., Chrisman, K., Bennett, M.E., Close, J.M., Stress, anticipatory stress, and psychologic measures related to sleep bruxism (1995) J Orofac Pain, 9 (1), pp. 51-56Axelbend, M., Vaile, J., South Florida's approach to police stress management (1979) Police Stress, 1, pp. 13-14Blackmore, J., (1978) Are police allowed to have problems of their own? Police Mag, 1, pp. 47-55Violanti, J.M., (1996) Police suicide: Epidemic in blue, , Springfield: Charles C Thomas;Neylan, T.C., Metzler, T.J., Best, S.R., Weiss, D.S., Fagan, J.A., Libermam, A., Critical incident exposure and sleep quality in police officers (2002) Psychosom Med, 64 (2), pp. 345-352Lipp, M.E.N., Guevara, A.J.H., Empiric validation of stress symptoms inventory (SSI) (1994) Estud Psicol, 11, pp. 43-49Pigno, M.A., Hatch, J.P., Rodrigues Garcia, R.C., Sakai, S., Rugh, J.D., Severity, distribution, and correlates of occlusal tooth wear in a sample of Mexican-American and European-American adults (2001) Int J Prosthodont, 14 (1), pp. 65-70Glaros, A.G., Incidence of diurnal and nocturnal bruxism (1981) J Prosthet Dent, 45 (5), pp. 545-549Ramfjord, S.P., Bruxism, a clinical and electromyographic study (1961) J Am Dent Assoc, 62, pp. 21-44Manfredini, D., Ciapparelli, A., Dell'Osso, L., Bosco, M., Mood disorders in subjects with bruxing behavior (2005) J Dent, 33 (6), pp. 485-490Manfredini, D., Landi, N., Fantoni, F., Segù, M., Bosco, M., Anxiety symptoms in clinically diagnosed bruxers (2005) J Oral Rehabil, 32 (8), pp. 584-588Wigdorowicz-Makowerowa, N., Epidemiological studies on prevalence and etiology of functional disturbances of the masticatory system (1979) J Prosthet Dent, 41 (1), pp. 76-82Collins PA, Gibbs ACC. Stress in police officers: a study of the origins, prevalence and severity of stress-related symptoms within a county police force. Occup Med. 2003;53(4):256-64Bültmann, U., Kant, I., Kasl, S.V., Beurskens, A.J., van der Brandt, P.A., Fatigue and psychological distress in the working population: Psychometrics, prevalence, and correlates (2002) J Psychosom Res, 52 (6), pp. 445-452Spielberg, C.C., Westberry, L.G., Grier, K.S., Greenfield, G., (1981) The police stress survey: Sources of stress in law enforcement, , Tampa FL, Human Resources Institute;Kirkcaldly, B., Cooper, C.L., Ruffalo, P., Work stress and health in a sample of U.S. police (1995) Psychol Rep, 76 (2), pp. 700-702Kroes, W.H., Gould, S., Job stress in policemen: An empirical study (1979) Police Stress, 1, pp. 9-10Violanti, J.M., Aron, F., Ranking police stressors (1994) Psychol Rep, 75 (2), pp. 824-826Violanti, J.M., Aron, F., Sources of police stressors, job attitudes and psychological distress (1993) Psychol Rep, 72 (3 PART 1), pp. 899-90

Anticaries potential of low fluoride dentifrices found in the brazilian market

CNPQ – CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOLow-fluoride (F) dentifrices (<600 µg F/g) are widely available worldwide, but evidence to recommend the use of such dentifrices, with either regular or improved formulations, is still lacking. Therefore, the aim of this study was to evaluate the anticaries potential of low-F dentifrices found in the Brazilian market, using a validated and tested pH-cycling model. Enamel blocks were selected by surface hardness (SH) and randomized into four treatment groups (n=12): non-F dentifrice (negative control), low-F dentifrice (500 μg F/g), low-F acidulated dentifrice (550 μg F/g) and 1,100 μg F/g dentifrice (positive control). The blocks were subjected to pH-cycling regimen for 8 days and were treated 2x/day with dentifrice slurries prepared in water (1:3, w/v). The pH of the slurries was checked, and only the acidulated one had low pH. After the pH cycling, SH was again determined and the percentage of surface hardness loss was calculated as indicator of demineralization. Loosely- and firmly-bound F concentrations in enamel were also determined. The 1,100 μg F/g dentifrice was more effective than the low-F ones to reduce enamel demineralization and was the only one that differed from the non-F (p<0.05). All F dentifrices formed higher concentration of loosely-bound F on enamel than the non-F (p<0.05), but the 1,100 μg F/g was the only one that differed from the non-F in the ability to form firmly-bound F. The findings suggest that the low-F dentifrices available in the Brazilian market, irrespective of their formulation, do not have anticaries potential27315CNPQ – CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOCNPQ – CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOsem informaçã

The Influence of Human-Milk Substitutes Marketing on Breastfeeding Intention and Practice among Native and Immigrant Brazilians

Background: The International Code of Marketing of Breast-Milk Substitutes is a global public health policy aiming to protect breastfeeding from the influence of human-milk substitutes marketing. Brazil is one of the few countries substantially implementing it. Most countries adopted selected provisions, including Portugal. Research Aim: To explore whether Brazilians’ perspectives about breastfeeding intention and practice are influenced by human-milk substitutes marketing upon migration to Portugal. Methods: A qualitative, prospective, cross-sectional survey design was conducted in Brazil and Portugal (2018–2019). Qualitative semi-structured interviews were performed with native (n = 16) and immigrant (n = 15) Brazilians. Women aged 18 or above, mothers of 0–12 month infants, and without contraindications to breastfeed, were eligible for the study. Heterogeneity sampling was employed based on socioeconomic status and infants’ age. Content analysis was conducted using NVivo. Results: Brazilian immigrants were more aware of the potential negative influence of human-milk substitutes marketing than natives. Sociocultural factors contributed to Brazilian immigrants being less permeable to the influence of human-milk substitutes marketing in the host country, where a less protective breastfeeding environment was perceived. Conclusions: Sociocultural factors including breastfeeding promotion strategies and a strong breastfeeding culture in the home country appear to play a protective role on breastfeeding intention and practice among Brazilians migrating to Portugal. © The Author(s) 2022.The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study is funded by FEDER funds through the Operational Programme for Competitiveness and Internationalization, and by national funding through the Foundation for Science and Technology (FCT; Portuguese Ministry of Science, Technology and Higher Education), under the scope of the project ‘‘Perinatal Health in Migrants: Barriers, Incentives and Outcomes’’ (POCI-01-0145-FEDER-016874; PTDC/DTPSAP/6384/2014), the projects UIDB/04750/2020 e LA/P/0064/2020, the PhD grant PD/BD/128082/2016 (C. L.) co-funded by the FCT and Human Potential Operating Program of the European Social Fund (POPH/FSE Program) and the contract DL57/2016/CP1336/CT0001 (C.F.). A. M. has a research scholarship from the Brazilian National Council for Scientific and Technological Development (CNPq)