摘要:

Experiments showed that the intraoral iodide permeability (Ip) method can be used in a reproducible and sensitive manner with solid foods. Ingestion of 5-gram portions of cookies made with defined concentrations of sucrose or fat led to an increased Ip (due to demineralization) of Streptococcus mutans-covered bovine enamel blocks in vivo. Demineralization increased with time to a maximum of 45 min, and the pH of the plaque dropped accordingly. Continued exposure in the mouth beyond 45 min led to an elevation of the pH and a decrease in delta Ip consistent with remineralization of the enamel. Control blocks worn without ingestion of cookies exhibited negative delta Ip values. Demineralization increased with increasing sucrose content of the cookies and reached a plateau when cookies containing 1.08 g sucrose per morsel were administered. Cookies prepared without added sucrose gave a high delta Ip. High fat content raised the delta Ip when sucrose was low. These findings are consistent with clinical and other observations, and emphasize the complex relation between foods and enamel demineralization.

ISSN:0008-6568    

DOI:10.1159/000261105

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

In this study the effect of X-ray irradiation on demineralization of bovine dental enamel in vitro was investigated. Enamel specimens were irradiated with 72 Gy and subsequently demineralized (140 h) under reproducible constant composition conditions at pH = 5 in the presence of methylhydroxydiphosphonate (MHDP). Microhardness measurements after demineralization without MHDP showed significant differences (p < 0.001) between irradiated and nonirradiated enamel specimens; no significant differences were found in the presence of MHDP. Quantitative microradiography showed that both mineral loss and lesion depth were significantly lower (p < 0.001) for the irradiated enamel specimens compared with the nonirradiated ones. Surface layer formation was observed in irradiated enamel demineralized in a solution without MHDP. It was shown that X-ray irradiation decreased the enamel acid solubility in vitro.

ISSN:0008-6568    

DOI:10.1159/000261106

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Six subjects wore intraoral devices carrying bovine enamel blocks covered with a layer of Streptococcus mutans. They swished solutions of 5% glucose or maltose, or sols or gels of 3, 5, 10, 15, or 20% gelatinized wheat starch in the mouth for 3 × 1 min. Demineralization was measured after 45 min by determining the change in iodide permeability (delta Ip) of the enamel. Spittings of the administered materials and samples of saliva, taken at intervals during the test, were analyzed for maltose, and the time of clearance was calculated. Demineralization was greatest for glucose followed by maltose, the starch gels, and the sols. The latter gave close to zero scores. The salivary clearance time increased with increase in concentration of the starch. Although the starch was hydrolyzed rapidly in the mouth, its oral retentiveness was greater than that of the maltose rinse. Demineralization was closely correlated with the final pH of the S. mutans cell layer. The data indicate that the starch in baked or cooked foods may have a significant demineralization potential and that it enhances oral retentiveness

ISSN:0008-6568    

DOI:10.1159/000261107

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

Foods and beverages containing sugars, frequently consumed as snacks between meals, contribute to dental caries in different proportions depending on a number of intrinsic factors, including carbohydrate content, textural properties, and mineral composition, such as calcium, phosphate, and fluoride concentration. A method to assay fluoride in foods and beverages is described which involves [1] an acid hydrolysis at 110°C in a closed vial with a valve for dispensing reagents and [2] estimation of total acid-hydrolyzed fluoride using a specific ion electrode. A number of foods, beverages, and diets were analyzed for acid-hydrolyzable and free fluoride. The simplicity of the method eliminates fluoride contamination, making the procedure accurate and reproducible in determining fluoride in foods and beverages

ISSN:0008-6568    

DOI:10.1159/000261108

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The relative glycogen synthetic and degradative activities of Actinomyces viscosus and Actinomyces naeslundii, freshly isolated from root surface caries and noncaries sites, were compared. The glycogen synthetic activity was measured by incubating glucose-(or sucrose-)grown resting cells with 100 mM glucose (or sucrose) and U-[14C]-glucose (or U-[14C]-sucrose) on a pH-stat maintained at 5.0, 6.0, and 7.0 for 1 h under anaerobic conditions. For the glycogen degradation assays, after the 1-hour incubation period, the cells were reincubated under similar conditions, but in the absence of external carbon sources. Carbohydrate utilization and total acid formation were also monitored. Both the glucose- and sucrose-grown cells of A. viscosus and A. naeslundii strains originating from root surface caries lesions synthesized approximately twice as much glycogen as the strains of noncaries origin. Although there were significant differences in the rates of glycogen synthesis, the rates of glycogen degradation were essentially the same for the Actinomyces strains from both caries and noncaries sites. However, the time required for glycogen degradation by the strains from caries sites was much longer. This study suggests that the abilities of A. viscosus and A. naeslundii originating from root surface caries lesions to synthesize large amounts of glycogen and to degrade this stored polymer slowly under conditions of starvation, particularly in an acidic environment, may be one of the factors contributing to the cariogenic potential of these organisms in root surface caries.

ISSN:0008-6568    

DOI:10.1159/000261109

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The level of Streptococcus mutans in saliva was determined by a dip-slide method in 841 13-year-old children in order to identify children with high caries risk. For each child, the flow rate of saliva was determined. Caries scores were obtained from Public Dental Health records. A sucrose intake score was calculated based on self-reported frequency of intake of six types of sugary products. As S.mutans counts increased, there was a significant trend of increased DMFS and DS scores. No linear correlation was observed between reported intake of sucrose and S. mutans counts, but the children with the highest counts (class 3) tended to have significantly higher sucrose intake than the rest of the children. The flow rate of saliva decreased significantly as S.mutans increased.

ISSN:0008-6568    

DOI:10.1159/000261110

出版商:S. Karger AG    

年代:1988

数据来源: Karger

ISSN:0008-6568    

DOI:10.1159/000261111

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The present study was designed to test the effect of frequent pulses of low fluoride levels on rat caries when supplied in a standardized cariogenic rat diet containing 67% sucrose (MIT-200). The test diets were variants of Diet MIT-200 in which the sucrose component had been fluoridated with NaF solution resulting in total concentrations of 0 (control), 2, 3, 5, 10, or 20 ppm fluoride in the final diets. Rats received one of the test lots 17 times daily in a programmed feeding machine, beginning at age 22 days, and were inoculated with Streptococcus mutans at age 23, 24, and 25 days. After 5 weeks, the rats were sacrificed and their mandibular molars scored for number and severity of sulcal, buccohngual, and proximal caries. Frequent daily pulses of as little as 2 ppm fluoride in dietary sucrose were effective in significantly (p < 0.01) reducing buccohngual rat caries.

ISSN:0008-6568    

DOI:10.1159/000261112

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The cariogenicity of frequent rinsings with aspartame and sorbitol was studied in the rat caries model with animals randomly assigned to four oral rinse groups (16 rats/group): 0.05% aspartame, 20% sorbitol, deionized distilled water, and 20% sucrose; all solutions at pH 3.0. After rinsing five times daily for 21 days, mandibular molars were scored for caries. Smooth surface, proximal and morsal caries scores did not differ significantly between groups. Moderate dentinal sulcal caries for the sucrose group was significantly greater than in the aspartame, sorbitol, and water groups (p < 0.05). Rinsing with 0.05% aspartame (similar in pH and concentration to that found in carbonated beverages) or sorbitol did not potentiate caries activity.

ISSN:0008-6568    

DOI:10.1159/000261113

出版商:S. Karger AG    

年代:1988

数据来源: Karger

摘要:

The cariogenicity of the following traditional African foods was tested in a rat model system; cooked maize and beans, cooked maize and spinach, uncooked and cooked sorghum, both plus 20% sucrose and brown bread, as well as a control (wheat starch plus 50% sucrose). Plaque extent was low in all the test groups and caries incidence was almost zero in all groups except for the cooked wheat starch and 50% sucrose group. Comparison to earlier results suggests a possible cariostatic effect of sorghum but not for the other traditional foods.

ISSN:0008-6568    

DOI:10.1159/000261114

出版商:S. Karger AG    

年代:1988

数据来源: Karger