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Biomedical subjects

B R Schemehorn

Publications and source records attributed to B R Schemehorn.

16 recordsLinked to original sources
PubMed1991

Use of an in vitro model to assess the effects of APF gel treatment on the staining potential of dental porcelain.

Porcelains and resin composites exposed to acidulated phosphate fluorides (APF) have been reported to result in increased roughness, loss of weight, and loss of specular reflectance (gloss). Six samples of five commercial porcelains were subjected to five four-minute treatments with APF gels. Samples were then subjected to a nine-day cyclic staining procedure that utilized a tea, coffee, and mucin mixture. Changes in reflectance were then measured by means of a Minolta Chromameter (CR121) and converted to CIE L* a* b* values at illuminant D65 against a white background. delta L*, delta a*, delta b*, and delta E values were calculated. There was a substantial decrease in the L* value (lightness) for all porcelains. The average L* value for APF-treated and then stained porcelains was 43.6, for the stained-untreated samples, 48.2, and for untreated-unstained porcelain, 53.5. For three of the five porcelains, the differences in L* between treated and untreated stained porcelains were statistically significant. Changes in a* and b* values were also found to be consistent with but not as large as the changes in L*.

Acidulated Phosphate Fluoride↗
PubMed1990

Effect of sorbitol gum chewing on plaque pH response after ingesting snacks containing predominantly sucrose or starch.

The purpose of this study was to determine the effect of chewing a sorbitol gum (Trident) for 10 minutes on interproximal plaque pH changes following ingestion of selected sucrose- or starch-containing foods. The snacks containing predominantly sucrose (and/or simple sugars) were chocolate bar, cream-filled cupcakes, cream-filled sandwich cookie, cherry pie and raisins. The snacks containing predominantly starch were oat cereal, granola bars, pretzels, potato chips and corn chips. Plaque pH responses were monitored using an indwelling wire-telemetry system in five adult panelists. The test design involved two sets of 5 x 5 Latin square randomization in which each set consisted of two series of tests. In the first series of tests, the fasted, resting plaque pH was recorded for 5 minutes, panelists ingested the designated snacks for 2 minutes, and the pH response was monitored for the remainder of a 2-hour period. In the second series of tests, the same procedure was followed through the snack ingestion. After the pH response to the snack was monitored for 15 minutes, the panelists were asked to chew one stick of sorbitol gum for 10 minutes and the pH response was then monitored for the balance of the 2-hour period. Results indicated that both the sugar- and starch-containing snacks tested in this study caused significant decreases in interproximal plaque pH. Chewing a sorbitol gum after ingestion of the snacks significantly reduced the demineralizing potential of the plaque. The chewing of sorbitol gum following the ingestion of snacks can be recommended as an adjunct to other caries-preventive oral hygiene measures.

Chewing Gum↗
PubMed1990

The impact of chewing sugarless gum on the acidogenicity of fast-food meals.

The objective of this study was to evaluate the effect of chewing sorbitol gum on plaque pH following the ingestion of acidogenic fast-food meals. Plaque pH response was monitored using an indwelling wire-telemetry system in five adult panelists. From a pilot study with 12 fast-food meals, the most acidogenic breakfast, lunch and dinner were selected for this study. In the first test, the fasted, resting plaque pH was recorded for 5 minutes; panelists ingested the selected meals for 10 minutes, rinsed thoroughly with 50 ml of tap water, and the pH response was monitored for the remainder of a 2-hour period. In the second test series, the same procedures were followed through the post-meal ingestion rinse. After the pH response to the meal was monitored for 5 minutes, the panelists chewed a sorbitol gum for 15 minutes in their usual manner and the panelists were encouraged to move the gum around their mouth, however, it appeared as if they favored the side of their mouth without the partial denture. The pH response was monitored for the balance of the 2-hour period. All panelists ate the test foods, with and without the chewing gum, according to a randomized-block test design. The results indicated that the use of sorbitol gum significantly raised the plaque pH, prevented the subsequent pH drops after the fast-food meal ingestion and reduced the pH curve area under 5.5.

Chewing Gum↗
PubMed1985

Factors relating to dental stain formation in the rat.

A series of studies was conducted to investigate the use of the rat as an in vivo model for studies of dental stain and to identify dietary factors which influence stain formation in this model. It was determined that appreciable amounts of stain formed on the molar teeth of rats provided a synthetic diet containing lactalbumin, and the amount of stain increased throughout a four-week test period. Stain formation was also observed when rats were provided their diet by gastric intubation. Topical applications of chlorhexidine generally resulted in an increase in stain formation, as did the presence of tea in the drinking water. These studies support the use of the rat for investigations of dental stain.

Animals↗
PubMed1985

Comparisons of various salivary parameters in smokers before and after the use of a nicotine-containing chewing gum.

This study was designed to compare various salivary parameters between smokers and non-smokers and to determine the influence of a nicotine-containing chewing gum (used to aid in quit-smoking efforts) upon these same parameters. At the baseline examination, subjects were assigned to one of three groups: non-smokers who did not utilize any gum, smokers provided a nicotine-containing gum, and smokers provided a placebo gum. Saliva was collected from all subjects and analyzed for acidogenicity and buffer pH as well as for levels of thiocyanate, lactoperoxidase, lysozyme, lactoferrin, and secretory IgA. After 15 weeks of gum usage, saliva was again collected from each subject and the identical analyses performed. Significant differences were observed between smokers and non-smokers with regard to three parameters: The saliva of smokers contained greater concentrations of thiocyanate and lower concentrations of lactoferrin, at the baseline examination and after the 15-week test period. In addition, the CO content of alveolar air was higher in smokers at both examination periods. In contrast, the use of the nicotine gum per se had no effect on any of the test parameters.

Adult↗
PubMed1985

In situ fluoride uptake from fluoride dentifrices by carious enamel.

A series of studies was performed to measure fluoride deposition in incipient caries-like lesions in enamel specimens contained in functional partial dentures in panelists who used fluoride dentifrices for periods ranging from two to nine weeks. The studies demonstrated the ability of the model to replicate the fluoride-uptake results obtained with a series of three dentifrices in two different panels of subjects. All fluoride dentifrices resulted in significant fluoride deposition, although significantly greater deposition was observed with a NaF-SiO2 dentifrice.

Adolescent↗
PubMed1979

A method for assessing the relative abrasion of prophylaxis materials.

A method for assessing the relative abrasion of prophylaxis materials is described. The method utilizes irradiated human enamel and dentin specimens, and treatments are performed using a simulated prophylaxis procedure. Results obtained with this method indicate that variations in treatment time, load, and cup speed may influence the relative abrasion.

Dental Enamel↗
PubMed1978

Influence of hexetidine upon plaque and gingivitis in the beagle dog.

Two studies were performed in beagle dogs to determine the effect of 0.2% hexetidine upon plaque and gingivitis. In both instances, hexetidine exerted no significant effect while 0.2% chlorhexidine resulted in reductions in both plaque and gingivitis of about 45 and 50%, respectively.

Animals↗
PubMedDate not supplied

Influence of fluoride upon plaque and gingivitis in the beagle dog.

Two studies were conducted to explore the effects of twice daily topical applications of NaF, SnF2, and an amine fluoride at equivalent fluoride concentrations (0.1%) upon plaque and gingivitis in the dog. Although some trends toward modest benefits were noted in certain instances, none of the agents exerted a significant effect upon either parameter.

Amines↗