Biomedical subjects

G Westbay

Publications and source records attributed to G Westbay.

4 recordsLinked to original sources

PubMed1993

Polymeric sealing of dentinal tubules to control sensitivity: preliminary observations.

The purpose of this study was to evaluate the effectiveness of a hydrophilic dentin primer to eliminate dentinal hypersensitivity to thermal stimuli. Eight patients enrolled in the study, with a total of 42 teeth having cervical sensitivity caused by erosion, abrasion, or periodontal therapy. All teeth were sensitive to cold air and tactile exploration. All test sites were rinsed with water, air-dried, and rubbed with a moist cotton pledget. Several coats of a dentin primer, consisting of N-tolylglycine-glycidyl methacrylate and bisphenyl dimethacrylate, were then applied with a brush to the exposed dentin and light-cured. All patients reported a complete absence of pain when the sites were retested with thermal stimuli immediately after treatment. After a 9-month period, seven patients remained symptomless, and one patient indicated slight sensitivity to ice. It was concluded that a single application of a hydrophilic dentin primer is highly effective in reducing or eliminating dentinal hypersensitivity to thermal stimuli for at least 9 months.

Composite Resins↗

PubMed1992

Salivary and metabolic factors involved in oral malodor formation.

Saliva plays a central role in the formation of oral malodor. Such formation has as its basis bacterial putrefaction, the degradation of proteins, and the resulting amino acids by microorganisms. Saliva provides substrates that are readily oxidized and in the process facilitates oxygen depletion. This favors the reduced conditions conducive to production of odoriferous volatiles. At the same time, saliva is a major source of oxygen for the oral bacteria which generally is inhibitory of their formation. The pH is also critical to malodor development; acidity inhibits, whereas neutrality and alkalinity favor malodor production. Since the pH on oral mucosal surfaces where odor formation occurs is largely determined by the fermentative and putrefactive activities of the adhering bacteria, these acid-base processes are necessarily of major regulatory importance. Because oral malodor and periodontitis both involve excessive oral putrefaction, a better understanding of putrefaction could lead to more substantive methods of oral malodor treatment than exists today, as well as identifying new approaches to amelioration of the bacterial attack on the soft tissues leading to the destruction associated with periodontal disease.

Dental Plaque↗

PubMed1990

Constituents of salivary supernatant responsible for stimulation of oxygen uptake by the bacteria in human salivary sediment.

The 10,000 g supernatant of wax-stimulated whole saliva was fractionated by gel filtration and its components were tested along with amino acids, small peptides and urea for their ability to stimulate this oxygen uptake, and for their effects on pH. Fractions containing the larger components, the proteins and large peptides, stimulated much less oxygen uptake than unfractionated supernatant, and caused a small decrease in pH. Analysis with anthrone indicated that both these effects were due mainly to the carbohydrate associated with these constituents. In contrast, fractions containing the remaining lower molecular-weight components stimulated substantial oxygen uptake and a rise in pH; both effects were like those seen with whole saliva supernatant. The oxygen effects were attributed mainly to certain amino acids and small peptides in the small molecular-weight fractions. Ornithine, arginine, proline and glutamic acid consistently stimulated oxygen uptake by the oral microflora in a test of 23 amino acids with the sediments of 13 subjects. Ornithine and arginine at the same time stimulated a significant rise in pH, whereas the other two amino acids showed no such effect. Variable and sometimes significant oxygen uptake was seen with alanine, aspartic acid, asparagine, glutamine and cysteine in 4-7 of the subjects; infrequent or no effects were seen with the remainder of the amino acids tested. There was some evidence to suggest that amino acid stimulation of oxygen uptake may be inducible. Urea had no effect on uptake but did contribute significantly to the pH rise. Small peptides containing those amino acids that could stimulate oxygen uptake also stimulated such uptake; peptides without such acids did not.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acids↗

PubMed1990

Oral malodor.

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Amino Acids↗