Ernest Newbrun

Physico-chemical characteristics of the levan produced by streptococcus salivarius

Abstract The levan from Streptococcus salivarius has an intrinsic viscosity of 0.15–0.16 dl/g. It sedimented as a single peak in the ultracentrifuge with a sedimentation constant of 215–217 S. The levan has a molecular weight of 16–23 million. The biological implications of these properties have been discussed.

Topical Fluoride Therapy: Discussion of Some Aspects of Toxicology, Safety, and Efficacy:

Although ingestion of an acute toxic dose of fluoride is extremely rare in dental treatments, practitioners should be familiar with the signs and symptoms and with emergency measures of treating accidental overdosage. The amount of fluoride ingested chronically from the use of self-applied topical fluoride can be reduced to safe limits by instructing parents to dispense small amounts of toothpaste for their young children and to ensure that fluoride dentifrices and mouthrinses are fully expectorated. Similarly, when custom-fitted trays are used, only minimal amounts of fluoride gels are necessary. The minimal amount of such gels that can be dispensed appears to be influenced by their viscosity. Clinical efficacy does not support a reduction in the concentration of fluoride in commercial dentifrices.

Current Treatment Modalities of Oral Problems of Patients with Sjögren's Syndrome: Caries Prevention

Prevention of dental caries in patients with hyposalivation due to Sjogrens syndrome requires increasing host resistance and decreasing cariogenic organisms and their substrate. Although plaque control by scrupulous oral hygiene is important, particularly from a periodontal perspective, and restriction of dietary sucrose intake can limit caries, the most successful therapeutic and preventive measure has been the topical application of fluoride to the tooth surface, by the dentist, dental hygienist, dental auxiliary, and the patient. Studies on schoolchildren with normal salivary function who used fluoride dentifrices have shown that efficacy in caries prevention depends on (1) the concentration of fluoride used, (2) the frequency with which it is applied, and, to a certain extent, (3) the specific fluoride compound used. Controlled clinical studies are lacking, however, on patients with hyposalivation due to Sjogrens syndrome, and only limited data are available from patients with radiation-induced hyposalivation. Obviously it is not possible to run placebo control groups; nevertheless, there have been no head-to-head comparisons of fluoride rinses, or of stannous fluoride, acidulated phosphate fluoride, or sodium fluoride gels, and thus no single protocol can be recommended. Accordingly, different centers have used these products interchangeably—for example, selecting a rinse regimen if patients complain of gagging when using a gel applied in a tray, or if the cost of the tray is prohibitive. Recent innovations that show promise for treatment of high-caries-risk patients with hyposalivation are the use of fluoride rinses in combination with chlorhexidine rinses or gels and the professional application of high-concentration chlorhexidine varnishes to the teeth.

Extracellular Polysaccharides Synthesized by Glucosyltransferases of Oral Streptococci

The aim of this study was to compare the chemical composition and susceptibility to enzymatic hydrolytic cleavage of several polysaccharides synthesized by glucosyltransferases obtained from oral stre

What we know and do not know about fluoride

Summary There is much that we know about fluoride as it relates to human health in general and dental health in particular. Some of the information that is known concerning water fluoridation and dental fluorosis is listed. What we do not know about fluoride is discussed in more detail, namely the efficacy of lower levels of fluoride in drinking water, the effect of discontinuing fluoride in drinking water in the absence of additional preventive measures, the prevalence of fluorosis and whether or not this presents a cosmetic problem. Other issues discussed include the actual amount of fluoride ingested from all sources, whether low-fluoride dentifrices are as efficacious as conventional dentifrices in caries protection and reducing enamel fluorosis, the role of socioeconomic factors in determining caries prevalence, and the effects of bottled water use on caries prevalence in fluoridated communities.There is much that we know about fluoride as it relates to human health in general and dental health in particular. Some of the information that is known concerning water fluoridation and dental fluorosis is listed. What we do not know about fluoride is discussed in more detail, namely the efficacy of lower levels of fluoride in drinking water, the effect of discontinuing fluoride in drinking water in the absence of additional preventive measures, the prevalence of fluorosis and whether or not this presents a cosmetic problem. Other issues discussed include the actual amount of fluoride ingested from all sources, whether low-fluoride dentifrices are as efficacious as conventional dentifrices in caries protection and reducing enamel fluorosis, the role of socioeconomic factors in determining caries prevalence, and the effects of bottled water use on caries prevalence in fluoridated communities.

Inhibition of Adherence of Streptococcus mutans to Glass Surfaces

Maltose and low-molecular weight dextran inhibited the adherence of Streptococcus mutans to the smooth glass surface of scintillation vials. Inhibition of adherence paralleled inhib

Effect of Flossing, with and without Iodine, on Human Interproximal Plaque Flora

Flossing per se temporarily reduces the proportion of Streptococcus mutans in interproximal plaque when these organisms are present in high numbers. Flossing with

Further Studies on Extracellular Glucans Synthesized by Glucosyltransferases of Oral Streptococci

Seven water-insoluble glucans were prepared enzymatically as described previously. In addition, glucan from Streptococcus mutans strain LM7 (serotype Lancefield Group E) was synthes

The Effect of Previous Diet on Plaque pH Response to Different Foods

In this study we investigated the effect of previous diet on the response of plaque pH to three test foods. The study population consisted of 11 dental students. Plaque pH was measured, by means of the touch electrode method, on the first two upper molars. The study was conducted at two sessions, one week apart. Subjects followed a 48-hour high-sugar diet before the first test session and a 48-hour low-sugar diet before the second test session. During both 48-hour periods, students refrained from all oral hygiene practices and fluoride utilization. At each session, three foods were ingested at one-hour intervals : cola, beer, and chocolate bar. pH measurements at baseline and at selected times after food ingestion were recorded and analyzed. Multivariate analysis of variance revealed significant independent effects of food, previous diet, and their interaction on plaque pH. After the same foods were ingested, plaque pH response after a previous high-sugar diet was significantly more acidic than after a previous low-sugar diet.

Vacuum treatment of tissue conditioners

1. issue-conditioning agents are used to improve the health of abused denture-bearing tissues’-3 and to make functional impressions for reline procedures.‘-lo For both of these uses, a uniform mix that incorporates minimal air in the tissue conditioner is desirable. The incorporation of air produces voids in the material, and voids are undesirable for several reasons. When the material is used as a tissue-conditioning agent, voids may harbor debris, bacteria,“,‘* and oral yeasts’3,‘4 that will further