Adsorption and availability of phosphorus in response to humic acid rates in soils limed with CaCO3 or MgCO3 / Adsorção e disponibilidade de fósforo em resposta a doses de ácido húmico em solos corrigidos por CaCO3 ou MgCO3

ABSTRACT Humic acid (HA) may reduce adsorption and increase soil P availability, however, the magnitude of this effect is different when Ca2+ prevails over Mg2+ in limed soils. The objective of this study was to evaluate the effects of HA rates and carbonate sources on the adsorption, phosphate maximum buffering capacity (PMBC), and P availability in two contrasting soils. Oxisol and Entisol samples were firstly incubated with the following HA rates: 0, 20, 50, 100, 200 and 400 mg kg-1, combined with CaCO3 or MgCO3, to evaluate P adsorption. In sequence, soil samples were newly incubated with P (400 mg kg-1) to evaluate P availability. The least P adsorption was found when 296 mg kg-1 of HA was added to Oxisol. Applying HA rates decreased maximum adsorption capacity, increased P binding energy to soil colloids and did not alter PMBC of Entisol. Available P contents in Oxisol increased with HA rates, but it did not change in Entisol. Choosing the right HA rate can decrease PMBC up to 40% and increase the Oxisol P availability by 17%. Application of MgCO3 instead of CaCO3 decreased P adsorption in both soils. Thus, a positive correlation between Ca2+ content and PMBC was verified. Optimum rate of HA and the preponderance of Mg2+ instead of Ca2+ in soil volume fertilized with P are effective practices to reduce adsorption and increase P availability, especially in clayey Oxisol.

RESUMO O ácido húmico (AH) pode reduzir a adsorção e aumentar a disponibilidade de P nos solos, entretanto, a magnitude desse efeito é diferente quando o Ca2+ prevalece sobre Mg2+ em solos com acidez corrigida. Objetivou-se avaliar os efeitos de doses de AH e fontes de carbonato na adsorção, fator capacidade de P máximo (FCPm) e disponibilidade de P em solos contrastantes. Amostras de Latossolo e Gleissolo foram primeiramente incubadas com as seguintes doses de AH: 0, 20, 50, 100, 200 e 400 mg kg-1, combinadas com CaCO3 ou MgCO3, para avaliar a adsorção de P. Em sequência, as amostras de solo foram novamente incubadas com P (400 mg kg-1), para determinar a disponibilidade de P. A aplicação de doses de AH reduziu a capacidade máxima de adsorção, aumentou a energia de ligação do P e não alterou a FCPm do Gleissolo. O teor de P disponível aumentou com o acréscimo das doses de AH no Latossolo, contudo, não foram alterados no Gleissolo. A escolha correta da dose de AH reduziu a FCPm em até 40% e aumentou a disponibilidade de P no Latossolo em 17%. A aplicação de MgCO3 em vez do CaCO3 reduziu a adsorção de P em ambos os solos. Assim, houve correlação positiva entre o teor de Ca2+ e a FCPm. A dose ótima de AH e a predominância de Mg2+ sobre Ca2+ no volume de solo adubado com P são práticas efetivas para reduzir a adsorção e aumentar a disponibilidade de P, especialmente, no Latossolo argiloso.

Qualitative and quantitative salivary changes and subjective oral dryness among patients with thyroid dysfunction

There is a paucity of literature regarding the effects of thyroid disorders on the oral cavity by influencing the salivary gland function. Aims: This study aims to understand the qualitative and quantitative changes that thyroid disorder can cause in the salivary function. Settings and Design: After obtaining ethical clearance, 46 consecutive newly diagnosed thyroid dysfunction patients were enrolled in this cross-sectional study, along with 45 age-and sex-matched controls. Subjects and Methods: Unstimulated and stimulated salivary flow rates, pH, and buffering capacity of the whole saliva were studied in addition to subjective oral dryness in the study participants. Statistical Analysis Used: The independent t-test was employed to compare the means between the two groups and Pearson's Chi-square test was used to assess the goodness of fit. Results: The findings showed that females are more affected with thyroid disorders and that hypothyroidism is more commonly reported than hyperthyroidism. A significant reduction in the salivary flow rates and buffering capacity was observed among the affected group compared to the controls, whereas the salivary pH did not show significant differences between genders and also between the case and control groups. A feeling of subjective oral dryness was perceived by many affected patients. Conclusions: The study was able to establish an association between thyroid dysfunction and salivary gland function. We hope that this study leads to more high-impact research in this field as salivary diagnostics is gaining more popularity with every passing day.

Evaluación de sobredentaduras mandibulares implanto-retenidas confeccionadas con técnica Rehabilitación Oral M/Prótesis, Facultad Odontología, Universidad de Concepción, en pacientes del Servicio Salud Bío-Bío / Evaluation of mandibular overdenture implant retained made with Oral Rehabilitation Prosthetic mention Technique from Faculty of Dentistry, University of Concepción, in patients Health Service Bío Bío

Los servicios asistenciales revelan interés por establecer protocolos de rehabilitación con sobredentaduras mandibulares retenidas a implantes, pero necesitan respaldo científico evaluado con instrumentos confiables. Objetivo: El objetivo de este estudio fue evaluar un modelo-protocolo de rehabilitación con sobredentaduras implanto retenidas para servicios públicos, por medio de test de rendimiento masticatorio, valores de retención y valoración de la satisfacción terapéutica obtenidos con las prótesis mandibulares implanto-retenidas. Materiales y métodos: Este trabajo fue realizado entre la Facultad de Odontología Universidad de Concepción (FAO-UDEC) y el Servicio de Salud Bío Bío (SS-BÍO-BÍO). Catorce pacientes fueron seleccionados, usuarios del SS-BÍO-BÍO, y recibieron sobredentaduras implanto-retenidas confeccionadas con protocolo del programa Rehabilitación Oral mención Prótesis (ROMPE. FAO-UDEC). Dos Implantes Neodent (3,75 × 11 y 13 mm) por paciente fueron instalados y conectados con carga temprana. Antes y después de instalar y conectar los implantes se evaluó: la satisfacción terapéutica con encuesta Programa ROMPE.FAO-UDEC, la retención con dinamómetro Force Gauge y el rendimiento masticatorio con test tamizado de maní. Los datos fueron procesados con programa SPSS 16.0 con test Kolmogorov-Smirnov, t-test para muestras relacionadas. Significación estadística p < 0,05. Resultados: La eficiencia masticatoria aumenta de forma significativa después de la conexión de los implantes. La satisfacción terapéutica con las prótesis y la resistencia a la tracción son altamente significativas posterior a la conexión de ellas. Conclusiones: Estos resultados son coincidentes con la gran mayoría de estudios publicados, y permiten sostener científicamente que el protocolo de confección de sobredentaduras ROMPE FAO-UDEC y SS-BÍO-BÍO es una alternativa confiable.

Health care services show interest in establishing rehabilitation protocols with mandibular overdentures retained on two implants, but they require scientific evidence evaluated with reliable instruments. Objective: To evaluate masticatory performance, retention and therapeutic satisfaction of patientswith a model rehabilitation protocol for implant-retained overdentures. Materials and methods: This study was conducted between the Faculty of Dentistry, University of Concepción (FAO UDEC) and Bío Bío Health Service(SS-Bío Bio). Fourteen patients, selected users of Bío Bío Health Service, Los Angeles, received implant-overdentures using a protocol of the Oral Rehabilitation Prosthesis Program (ROMPE FAO UDEC). Two Neodent™ implants (3.75 × 11 and 13 mm) were installed in each patient and connected with early loading. Before and after installing and connecting the implants, (0, 30 and 60 days), therapeutic satisfaction was assessed using the ROMPE FAO UDEC graduate program questionnaire. Retention was measured with a Force Gauge Dynamometer, and masticatory performance was quantified with a peanut screening test. Data were processed with SPSS 16.0 program and Kolmogorov-Smirnov test and t- test were used. Significance was set at P < .05. Results: Masticatory efficiency significantly increases after connectingthe implants. Therapeutic satisfaction with the prosthesis and the tensile strength are highly significant. Conclusions: These results coincide with the vast majority of published studies. It can be scientifically argued that the ROMPE FAO UDEC, SS Bío Bío overdenture protocol is a reliable alternative.

Capacidad buffer de la saliva en presencia de bebidas energéticas comercializadas en Chile, estudio in vitro / In vitro study of the buffering capacity of saliva in the presence of energy drinks sold in Chile

OBJETIVO Determinar la capacidad buffer de la saliva al ser añadida a distintas bebidas energéticas comercializadas en Chile, mediante mediciones de pH in vitro. MÉTODOS Fue requerida la participación de 3 pacientes jóvenes sistémicamente sanos, sin enfermedad de las glándulas salivales. Las muestras de saliva estimulada fueron obtenidas de cada paciente, las cuales fueron mezcladas y almacenadas en una sola muestra. Se seleccionaron 13 bebidas energéticas comercializadas a nivel nacional. Un total de 5 mL de cada bebida energética se distribuyó en 4 tubos Falcon. Se midió el pH de cada una de las bebidas energéticas, de la saliva y del agua potable. Se añadió 1 mL de agua potable al tubo Falcon número 1 y 1 mL de saliva a los 3 tubos restantes, cada 3 min hasta completar 13 mL de solución en cada uno (38% vol./vol.). Las mediciones de pH fueron realizadas en cada 1 mL añadido (saliva/agua), para permitir al ph-metro registrar de manera correcta. RESULTADOS Los rangos de pH para las bebidas energéticas van desde pH 2,42 ± 0,008 (Battery Gingered®), hasta pH 3,44 ± 0,005 (Battery Sugar Free®). La saliva en promedio tuvo un valor de pH 7,99 y el agua potable de 7,05. La bebida que más logró aumentar el pH, luego de agregar la saliva, fue la bebida Speed® que llegó a un valor de pH 4,38, mientras la que logró menos fue la bebida Quick Energy®, con un valor de pH 3,37. CONCLUSIÓN La capacidad buffer de la saliva logró aumentar entre 17 y 54% el pH de las bebidas energéticas analizadas en este estudio. Sin embargo, no pudo neutralizar los bajos niveles de pH de estas bebidas más allá de un pH final de 4,38, que es crítico para la estructura dentaria.

OBJECTIVE To determine, using in vitro pH measurements, the buffering capacity of saliva when added to different energy drinks sold in Chile. METHOD The participation of 3 young and systemically healthy patients, with no diseases of the saliva glands, was obtained. Samples of stimulated saliva where obtained from each patient and then mixed and stored as one sample. The study used 13 energy drinks sold nationwide, with 5 mL of each one being distributed into 4 Falcon tubes. The pH of each of the energy drinks, the saliva sample, and drinking water was measured. 1 mL of drinking water was added into Falcon tube number 1, and 1 mL of saliva into the 3 remaining every 3 min until completing 13 mL of solution in each one (38% vol./vol.). The pH measurements where performed upon adding each 1 mL (saliva/water) to allow the pH meter to correctly register the data. RESULTS The pH levels for energy drinks range between pH 2.42 ± 0.008 (Battery Gingered®), to pH 3.44 ± 0.005 (Battery Sugar Free®). The saliva had a mean pH value of 7.99, and 7.05 for drinkable water. The energy drink that achieved a higher increase in pH level was Speed®, reaching a value of pH 4.38, while the energy drink that increased the pH level the least was Quick Energy®, only reaching a pH of 3.37. CONCLUSION The buffering capacity of saliva managed to increase the pH level of energy drinks analyzed in this study between 17 and 54%. However, saliva was unable to neutralize further than 4.38 the low levels of pH in these drinks, thus being critical to dental structure.

Capacidad amortiguadora y ph salival en mujeres en etapa reproductiva y menopáusica por efecto de la terapia hormonal: prueba piloto / Buffer capacity and salivary ph in menopausal and reproductive age women by hormonal therapy effect: pilot study

El propósito de este estudio fue evaluar la capacidad amortiguadora y pH salival de mujeres en etapa reproductiva sin terapia hormonal, con [anticonceptivos] (AC) y en etapa menopáusica. Se recolectaron muestras de saliva estimulada (SE) y no estimulada (SNE) en 9 mujeres de entre 33 y 56 años de edad, las cuales se dividieron en tres grupos; el grupo 1, constituido por mujeres en etapa reproductiva sin terapia hormonal (grupo control), el grupo 2, constituido por mujeres en etapa reproductiva con terapia hormonal [anticonceptivos] AC y el grupo 3, constituido por mujeres en etapa menopáusica. La capacidad amortiguadora salival se determinó por titulación ácido-base utilizando el método descrito por Singer y col. (1983). El pH se midió en un potenciómetro marca Orion, modelo 710A y un electrodo para pH Accumet Fisher Scientific. La capacidad amortiguadora en SNE fue de (7,8±2,0) en el grupo control; (38,1±22,4) en las mujeres con terapia hormonal (AC) y (12,6±2,4) en el grupo de mujeres menopáusicas. Cuando se evaluaron las muestras de SE, el comportamiento fue similar y los resultados observados fueron (37,56±20,84) en el grupo 2 respecto al control (13,8±3,2). No se observaron cambios en el pH tanto de la SE como SNE en los grupos evaluados a excepción del grupo 2 donde el pH fue significativamente menor (p<0,05). Los resultados parecieran indicar que el uso de terapia hormonal con anticonceptivos (estrógenos) produce una modificación tanto en el pH como en la capacidad amortiguadora de la saliva...

The purpose of this study was to evaluate the salivary pH and buffering capacity of reproductive age women, without hormonal therapy, with [contraceptive] (CC) and menopausal. Samples of stimulated (SS) and unstimulated (USS) saliva were collected in 9 women between 33 and 56 years old, which were divided into three groups; Group 1, consisting of women of reproductive age without hormonal therapy (control group), group 2, consisting of women of reproductive age with hormone therapy [contraceptive] (CC) and group 3, consisting of menopausal women. Salivary buffering capacity was determined by acid-base titration using the method described by Singer et al. (1983). The pH was measured with an Orion potentiometer, model 710A and a Fisher Scientific Accumet electrode. The buffering capacity in SNE, was (7.8±2.0) in the control group, (38.1±22.4) in women with AC and (12.6±2.4) in the group of menopausal women. When samples were evaluated SE, the behavior was similar and the observed results were (37.56±3.2) in group 2 over control group (13,8±3,2). No changes in the pH of both the SE as SNE evaluated in groups 2 , group except where the pH was significantly lower (p<0.05). The results seem to indicate that use of hormonal contraceptive therapy (estrogens) causes a change in both the pH and buffering capacity of saliva...

Role of amylase, mucin, IgA and albumin on salivary protein buffering capacity: A pilot study.

It has been suggested that proteins serve as major salivary buffers below pH5. It remains unclear, however, which salivary proteins are responsible for these buffering properties. The aim of this pilot study was to evaluate the correlation between salivary concentration of total protein, amylase, mucin, immunoglobulin A (IgA), albumin and total salivary protein buffering capacity at a pH range of 4–5. In addition, the buffering capacity and the number of carboxylic acid moieties of single proteins were assessed. Stimulated saliva samples were collected at 9:00, 13:00 and 17:00 from 4 healthy volunteers on 3 successive days. The buffering capacities were measured for total salivary protein or for specific proteins. Also, the concentration of total protein, amylase, mucin, IgA and albumin were analysed. Within the limits of the current study, it was found that salivary protein buffering capacity was highly positively correlated with total protein, amylase and IgA concentrations. A weak correlation was observed for both albumin and mucin individually. Furthermore, the results suggest that amylase contributed to 35% of the salivary protein buffering capacity in the pH range of 4–5.

Effect of commercial alcoholic drinks on sound enamel surface of bovine teeth / 대한구강보건학회지

OBJECTIVES: The purpose of this study was to evaluate the change in surface microhardness of sound enamel of bovine teeth due to commercial alcoholic drinks. METHODS: The experiment group comprised of wines, makgeollis, and beers with low pH, while distilled water was used as the control. The two experiment groups were administered soju having the highest (SojuH) and lowest (SojuL) pH. Drinking wines were classified into 2 groups: agitated (wine A) and non-agitated (wine NA) wines. The pH values, buffering capacity, and concentrations of fluorine, calcium, and phosphorus of both the wine groups were measured. Eighty-four bovine specimens were divided into seven groups (N=12) and were immersed for 1, 3, 5, 10, 30, 60, and 120 min, respectively. The surface microhardness was measured using a microhardness tester before and after treatment with each alcoholic drink. After 120 min, the enamel surface was examined using a scanning electron microscope (SEM). The statistical methods used in this study were one-way analysis of variance (ANOVA) and repeated-measure ANOVA. RESULTS: The differences in the surface microhardness (DeltaVHN) values obtained before and after treatment for 120 min were statistically significant among groups. Makgeolli, wine A, and wine NA significantly eroded the enamel after 120 min. However, sojuH and sojuL had an effect similar to that of distilled water, which was used in the control group. Beer caused slight enamel erosion. SEM images revealed that makgeolli, wine A, and wine NA caused significant erosion of the enamel surface, while beer caused slight erosion. SEM observation results were similar to those obtained after surface microhardness evaluation. CONCLUSIONS: The study findings suggest that alcoholic drinks, such as makgeolli and wine, with organic acids and a pH value less than 4.0 can cause tooth enamel erosion. Therefore, alcoholic drinks with low pH values and organic acid composition should not be retained for long periods in the mouth.

Flujo y capacidad amortiguadora salival en dos grupos de sujetos de 6 a 11 años de edad con bajo y alto índice de dientes cariados, perdidos y obturados / Salivary flow and buffer capacity in two 6-to-11-year-old groups of subjects with low and high decayed, missing and filled teeth index

Objetivo: comprobar la relación entre el flujo y la capacidad amortiguadora salival con la experiencia de caries, en niños con bajo y alto índice de dientes cariados, perdidos y obturados (CPOD). Método: Se realizó un estudio descriptivo transversal a un grupo de 60 niños de 6 a 11 años de edad, de ambos sexos, admitidos para consulta en la Clínica de Admisión de la Facultad de Odontología de la Universidad Autónoma de Baja California, sede Mexicali. Se establecieron dos grupos en función del CPOD: grupo 1 (puntuación 0-3) y grupo 2 (4 o más). Se elaboró una historia clínica que incluyó tanto los datos generales del niño como el registro de la experiencia de caries bajo los criterios de la Organización Mundial de la Salud. Asimismo, se midieron y registraron el volumen de saliva estimulada y la capacidad amortiguadorapara cada sujeto. Resultados: se observó una correlación negativa (r=–0,221) entre el flujo salival y el CPOD; sin embargo, esta tendencia no fue estadísticamente significativa (p>0,05). En cuanto a la capacidad amortiguadora, se hallaron diferencias estadísticamente significativas al relacionar una mayor capacidad amortiguadora y un CPOD bajo (p<0,05). Conclusión: la mayor capacidad amortiguadora de la saliva se relacionó con la menor experiencia de caries. Por su parte, el flujo salival estimulado mostró alguna asociación descriptivamente con el CPOD, pero dicha asociación no fue estadísticamente significativa.

Objective: Demonstrate the association between salivary flow and buffer capacity with caries experience in children with low and high Decayed, Missing and Filled Teeth Index (DMFT). Methods: A cross-sectional study was conducted with 60 6-to-11-year-old children of both sexes, who attended the Dental School of Universidad Autónoma de Baja California, Mexicali campus. The patients were assigned to two groups according to the DMFT score, group 1 (score 0-3) and group 2 (score 4 or more). A clinical record including patient’s general information and dental evaluation was filled out. Cavity experience evaluation was carried out following WHO parameters. Also, salivary flow and buffer capacity were measured in each individual. Results: A weak negative correlation between salivary flow and DMFT score was observed (r=–0.221); however, this trend was not statistically significant (p>0.05). Regarding the buffer capacity, statistically significant differences between this salivary property and DMFT were found (p<0.05). Conclusion: The buffer capacity of saliva was associated with lower caries experience. On the other side, stimulated salivary flow show was not found to be related with the DMFT score.

Buffering capacity and membrane H+ conductance of protease producing facultative alkaliphilic bacterium Bacillus flexus from mangrove soil. Indian Journal of Biochemistry & Biophysics. 2009 June; 46(3): 261-265.

A facultative alkaliphilic protease-producing gram-positive rod-shaped bacteria (EMGA 5) was isolated from mangrove soil and confirmed as Bacillus flexus by the 16S rDNA sequence. Buffering capacity and membrane H+ conductance of this alkaliphilic isolate were investigated for the cells grown at pH 7.2 and 10.5 using acid pulse technique. Suspensions of B. flexus cells grown in poly peptone yeast glucose medium at pH 10.5 exhibited higher cytoplasmic membrane buffering capacity values (70 µmol H+/pH unit/mg protein at pH 9.9) than the cells grown at pH 7.2 (41 µmol H+/pH unit/mg protein at pH 9.9). B. flexus grown aerobically at pH 7.2 showed higher H+ conductance values than the cells grown at pH 10.5 (0.032 µmol H+/s/pH unit/mg protein at pH 9.9 and 0.028 µmol H+/s/pH unit/mg protein at pH 9.8, respectively). The present study revealed that the buffering capacity and membrane H+ conductance of the B. flexus isolates were influenced by pH of the medium.

A Further Note on the Sampling Device for the Anti-Mutagenicity of Saliva

Objectives: The purpose of this study was to compare the anti-mutagenicity of Salivette and test-tube sampling saliva. In addition, the relation between the inhibiting and pH-buffering capacities of saliva was investigated. Methods: Subjects were 52 healthy female university students. The collection of saliva samples was carried out using 2 sampling devices; test-tube and Salivette. The anti-mutagenicity of the saliva was measured using the umu test. Results: The inhibiting capacity of Salivette-saliva was significantly lower compared with that of test-tube-saliva (p<0.01, t test). However, there was a significant correlation between them (r=0.35; p<0.05). In addition, there was a significant correlation between the inhibiting and pH-buffering capacities of saliva (r=−0.36; p<0.05). Conclusions: These findings suggest that both the Salivette and the test-tube may be appropriate as saliva-sampling devices. In addition, they suggest that the bicarbonates might inhibit the anti-mutagenicity of saliva, or that the activity of substances related to the anti-mutagenicity of saliva might be dependent on pH.

A further note on the sampling device for the anti-mutagenicity of saliva

<p><b>OBJECTIVES</b>The purpose of this study was to compare the anti-mutagenicity of Salivette and test-tube sampling saliva. In addition, the relation between the inhibiting and pH-buffering capacities of saliva was investigated.</p><p><b>METHODS</b>Subjects were 52 healthy female university students. The collection of saliva samples was carried out using 2 sampling devices; test-tube and Salivette. The anti-mutegenicity of the saliva was measured using the umu test.</p><p><b>RESULTS</b>The inhibiting capacity of Salivette-saliva was significantly lower compared with that of testube-saliva (p<0.01,t test). However, there was a significant correlation between them (r=0.35; p<0.05). In addition, there was a significant correlation between the inhibiting and pH-buffering capacities of saliva (r=-0.36; p<0.05).</p><p><b>CONCLUSIONS</b>These findings suggest that both the Salivette and the test-tube may be appropriate as saliva-sampling devices. In addition, they suggest that the bicarbonates might inhibit the anti-mutagenicity of saliva, or that the activity of substances related to the anti-mutagenicity of saliva might be dependent on pH.</p>