Dental Plaque pH Research Articles

An in-dwelling electrode for in-vivo measurement of the pH of dental plaque in man

A system for the measurement of plaque pH in vivo has been developed, using an in-dwelling miniature glass electrode. The reliability of the electrode and the closeness of the experimental conditions to natural ones compared favourably with previous techniques for measuring plaque pH. The effect on plaque pH of sucrose and saccharin rinses, and a chlorhexidine mouthwash were studied. Continuous small, rapid fluctuations in the pH of both stimulated and resting plaques were consistently observed and larger changes of pH were noted on opening the mouth and swallowing.

Continuous Monitoring of pH and Eh in Bacterial Plaque Grown on a Tooth in an Artificial Mouth

Apparatus which enables the simultaneous continuous monitoring of pH and Eh of bacterial dental plaque as it develops on a tooth surface in an artificial mouth is described. Details of the electrodes used, monitoring equipment, and culture conditions are given. Preliminary results are given showing the Eh and pH values of plaque produced in vitro to be in close agreement with readings reported for plaque in vivo. The effect of the incorporation of 1% sucrose in the medium on these parameters is reported and a distinct inverse relationship between pH and Eh recorded.

Continuous Monitoring of pH and Eh in Bacterial Plaque Grown on a Tooth in an Artificial Mouth

Apparatus which enables the simultaneous continuous monitoring of pH and Eh of bacterial dental plaque as it develops on a tooth surface in an artificial mouth is described. Details of the electrodes used, monitoring equipment, and culture conditions are given. Preliminary results are given showing the Eh and pH values of plaque produced in vitro to be in close agreement with readings reported for plaque in vivo. The effect of the incorporation of 1 per cent sucrose in the medium on these parameters is reported and a distinct inverse relationship between pH and Eh recorded.

Influence of sugar content in soft bread on pH of human dental plaque.

Quantitative determination of monosaccharides, disaccharides and sorbitol by use of gas-liquid chromatography (GLC) was performed on thirty-three samples of different commercial soft bread. Maltose was found in all the bread samples. Fructose and glucose were found only in samples of sweetened bread. Sucrose was detected in 5 samples, lactose in 2, and sorbitol in 2. Up to 20 per cent of the fresh bread weight was found to be low-molecular weight carbohydrates. Plaque pH-changes were studied in 18 persons following a 30-second month rinse with each of 3 solutions: (1) 50% sucrose, (2) water extract of sweetened bread, and (3) water extract of unsweetened bread. Mouth rinsing with the extract of sweetened wheat bread (sucrose 7.7 per cent of the dough weight) caused pH-decreases in plaque which were significantly more pronounced than those induced by the water extract of unsweetened wheat bread.

The effect of chewing on the ph of dental plaques after carbohydrate consumption.

Eighteen volunteers were given a mouth rinse with a 50 per cent sucrose solution and the pH of superficial dental plaque was measured electrometrically after 2, 5, 10, 20 and 30 minutes either when the person was continuously chewing paraffin or without paraffin chewing. The paraffin was chewed on one side of the mouth and the samples for measurement of the pH were taken from the other side of the mouth. In one series of experiments paraffin was chewed but the mouth was not rinsed with the sugar solution. The results revealed that the pH-decrease caused by the sugar rinse was diminished significantly by chewing. Chewing paraffin raised the pH by about 0.4, compared with the initial pH-values recorded after 10 minutes. This pH-increase lasted throughout the experimental period of 30 minutes. The difference was statistically significant.

A radiotelemetric method for the study of pH and fluoride-ion concentration in dental plaque and saliva.

Telemetry has been applied to dental research for ten years in the field of tooth-contact studies. The measurement of specific ion levels in oral fluid and in dental plaque also requires telemetric investigation, but the technical problems involved have resulted in slow development of oral telemetry in this field. A suitable method is described for thein vivo telemetric recording of pH and fluoride-ion concentration from dental plaque. The miniaturised transmitter construction is described and the theory of operation explained, together with the type and fabrication of suitable transducers. The equipment available for reception of the oral signal, together with modifications where necessary, is described, and the method of conversion of the radio signal to a recordable voltage is also explained.

Determination of saliva and dental plaque pH in hamsters with glass micro-electrodes

Measurements of the pH of saliva, conjunctival fluid and dental plaques in situ were made in hamsters receiving a caries-conducive diet, by the use of glass microelectrodes specific for hydrogen ions. The pH of conjunctival fluid ranged between 6.3 and 7.3. The pH values for saliva ranged between 6.3 and 9.0 depending on the exposure to air, and presumably the amount of CO 2 lost to the air. All dental plaques fermented sucrose but only in hamsters in which dental caries was developing as a result of infection with cariogenic streptococci did the plaques ferment sucrose rapidly and attain strongly acid values. Thus caries in hamsters, like caries in man, seems to be associated with acidogenic activity of microbial plaques.

Studies on Dental Plaque. I. The Effect of Different Concentrations of Glucose on the pH of Dental Plaque in Vivo

Studies on Dental Plaque. I. The Effect of Different Concentrations of Glucose on the pH of Dental Plaque in Vivo