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Poor nutrition is a risk factor for dental decay in younger people. However, except for sugar, it is unclear if this is true in older age groups. The aim of this study was to analyze the possible associations between overall dietary intake of nutrients and diet quality and the presence of dental decay in community-dwelling older men. A cross-sectional analysis of a longitudinal study with a standardized validated diet history assessment and comprehensive oral health examination in 520 community-dwelling men (mean age: 84 years) participating in the Concord Health and Ageing in Men Project. Nutrient reference values were used to determine if individual micronutrients and macronutrients were meeting recommendations. Acceptable macronutrient distribution ranges (AMDRs) were attained for fat and carbohydrate intakes and were incorporated into a dichotomous variable to determine if the participants were consuming a high fat-low carbohydrate diet. Diagnosis of coronal caries was based on visual criteria and inspection and was completed on each of the five coronal surfaces. Root surface caries was textual changes across four root surfaces. This diagnosis was used to categorize participants by the presence and severity of coronal and root caries. The adjusted logistic regression showed not meeting the recommended intakes for thiamin (odds ratio [OR]: 2.32 95% confidence interval [CI] 1.15-4.67), and zinc (OR: 3.33, 95% CI: 1.71-6.48) were associated with presence of severe root decay. Adjusted analysis also showed that participants who were outside the recommended AMDR for fat (OR: 0.61, 95% CI: 0.38-0.98) and those who consumed a high fat and low carbohydrate diet (OR: 0.56, 95% CI: 0.35-0.91) were less likely to have coronal tooth decay. Our study shows associations between micronutrients and macronutrients and coronal and root surface decay. Although this study cannot prescribe causality or be generalized to all older adults, diet has a possible association with dental decay in older men., (© 2024 S. Karger AG, Basel.)

Direct or in situ methods (e.g., confocal microscopy, microsensors) are used to study non-oral biofilms for almost two decades, and they have recently been introduced in the research of dental plaque. We combined a pH microsensor technique and transversal microradiography (TMR) in a pilot study where the effects of nutrient availability on plaque acidogenicity and on the development of caries-like lesions were assessed. One volunteer accumulated dental plaque for 7 days in 0.2-mm-wide and 0.8-mm-deep dentin grooves at four conditions: (1) saliva only, (2) 8 x 5 min/day dipping in 10% sucrose solution, (3) 7 x 5 min/day consumption of sweet cookies plus one meal/day, and (4) subject's regular diet. Plaque pH versus time and depth profiles in the grooves were recorded ex vivo before and after sugar challenge. 'Saliva' plaque responded to sugar with slow pH decrease--minimum pH 5.6-5.8 was reached after 30 min, while sugar dipping resulted in metabolically active plaque (minimum pH 5.3-5.5 within 4-8 min). TMR analysis revealed no demineralization after these two periods. Metabolically active plaque leading to distinct lesions resulted from frequent plaque exposure to diets rich in starch and carbohydrates (groups 3 and 4). These findings strengthen the view that the plaque acidogenicity does not necessarily reflect cariogenicity, and that retention of food components may account for increased cariogenicity at plaque retention sites in the mouth., (Copyright 2004 S. Karger AG, Basel)

Previously, a mixed culture chemostat system was used to demonstrate that the pH generated from carbohydrate metabolism, rather than carbohydrate availability per se, was responsible for the shifts observed in the oral microflora which are associated with high carbohydrate diets and the development of dental caries. The aim of this study was to determine more accurately the microbially generated pH at which such shifts occurred. Nine oral bacteria were grown in three independent chemostats, and pulsed with glucose on 10 consecutive days. In one chemostat, pH control was discontinued for 6 h, and the pH fall was restricted to a minimum value of pH 5.5; the pH fall was arrested in the other two chemostats at either pH 5. 0, or at pH 4.5. When the pH was allowed to fall, the numbers and proportions of Streptococcus mutans and Lactobacillus rhamnosus increased; this increase was directly related to the magnitude of the pH fall. Veillonella dispar was the most numerous organism following all glucose pulsing regimes, especially at low pH. The increase in proportions of acidogenic bacteria was accompanied by a fall in the proportions of acid-sensitive species (Fusobacterium nucleatum, Prevotella nigrescens, Streptococcus gordonii and Streptococcus oralis). The counts of these species were relatively stable between pH 5.5 and 4.5, but were markedly reduced when the pH fell below pH 4.5; Neisseria subflava could not persist in the culture at pH 4.5 or below. The data suggest that the disruption of communities associated with glucose metabolism and low pH can be explained in terms of a two-stage process. A fall in pH to a value between pH 5.5 and 4.5 may allow the enrichment of potentially cariogenic species, whilst permitting species associated with health to remain relatively unaffected. A further reduction in pH (

The cariogenicity of starches and fruits was investigated by measuring acidogenicity (plaque sampling) and enamel demineralization. Test foods were oranges, apples, bananas, Cornflakes, Branflakes, Weetabix, Alpen (no added sugar), white bread, wholemeal bread, rice, and spaghetti, with positive and negative controls of sucrose and sorbitol. Plaque sampling indicated that all the foods were less acidogenic than sucrose, but only significantly so (p < 0.05), as follows: maximum drop in plaque pH: all foods; minimum plaque pH reached: Cornflakes, Branflakes, and wholemeal bread; cH area: wholemeal bread. All foods produced enamel demineralization. The low pH of oranges and apples caused more demineralization than sucrose. Overall, the foods were less cariogenic than sucrose, but more than sorbitol.

There is considerable evidence for an association between dental caries and food starches. However, the intraoral utilization of starch may be quite complex, giving rise to conflicting results. Demineralization induced by unsweetened cookies was examined in an intraoral model system that utilized palatal appliances containing blocks of bovine enamel. The enamel surfaces were covered with either a filter paper disc to trap sugars or a layer of Streptococcus mutans to metabolize the sugars and bring about enamel demineralization. Demineralization was determined as an increase in porosity with respect to iodide ions (delta Ip). Measurements revealed a rapid elevation and maintenance of high levels of maltose in the plaque space after ingestion of the unsweetened or sweet cookies. Entrapped food particles appeared to serve as a reservoir of maltose. Unsweetened cookies brought about enamel demineralization, but the pH of the streptococcal plaque fell slowly, and the initiation of demineralization was delayed. Thus, delta Ip and plaque pH were -0.3 +/- 1.3 U and 6.1 +/- 0.3, respectively, after 15 min. The delay was shown to be related to the need to induce the acidogenic streptococci to metabolize maltose. Once induced, delta Ip rose rapidly and reached a maximum at 45 min. Sweet cookies released sucrose and maltose and brought about a rapid onset of demineralization. In summary, the data demonstrated (1) that maltose was released rapidly from unsweetened cookie particles and diffused into the plaque space of the model system and (2) that maltose-dependent demineralization of enamel required time for the induction of the streptococcal cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Development of caries in man is associated with dietary sugars, but the relationship between sugar contents of individual foods and their cariogenic potential is unclear. A recent report categorized dietary sugars as intrinsic (mainly fruit and vegetable) and extrinsic (mainly added sugars, milk, and fruit juices) and concluded that consumption of extrinsic sugars (except milk) should be replaced with that of intrinsic sugars. This paper examines briefly the dental consequences of the recommendations.

A model system was used to examine the relation between the duration of plaque pH fall and enamel demineralization following the intake of dietary carbohydrate in humans. Subjects wore palatal appliances containing blocks of bovine enamel covered with Streptococcus mutans IB 1600, and rinsed with 5 or 10% sucrose. Changes in iodide penetrability (delta Ip) of the enamel, and the pH and extracellular calcium and inorganic phosphate (Pi) concentrations of the streptococcal plaque were determined. Following rinses with 5% sucrose, delta Ip increased with time and reached a maximum (11.2 +/- 2.2 units) at 45-60 min although the S. mutans plaque remained acidic (pH = 4.8 +/- 0.6). After 10% sucrose, the maximum (14.7 +/- 3.1 units) was reached while the plaque pH was 4.0 +/- 0.3. Second rinses with sucrose increased delta Ip at most by 30%. Thus, demineralization did not persist throughout the period of low plaque pH, but occurred primarily during the early phase of plaque acidogenesis. Enamel demineralization appeared to be limited by factors other than the pH of the streptococcal plaque. Calcium concentrations in the S. mutans plaque rose to a maximum of 10.9 +/- 2.8 mEq/l at 30 min after the 5% sucrose rinses, then fell; Pi reached a stable level of 12.2 +/- 2.3 mEq/l by 60 min. Calculations showed that conditions approached saturation with respect to enamel and dicalcium phosphate dihydrate as demineralization reached a maximum. Demineralization appeared to be limited at low plaque pH, therefore, by the accumulation of high levels of mineral ions in the streptococcal plaque.(ABSTRACT TRUNCATED AT 250 WORDS)

The effects of hyposalivation on the induction of dental caries and on the composition of the oral microflora were examined in specific pathogen-free Sprague-Dawley rats fed either a sucrose or a wheat flour diet with or without inoculation of Streptococcus mutans. Significant dental caries was induced in hyposalivated rats fed diet 2000 containing 56% sucrose, irrespective of infection by S. mutans. Diets containing 56% wheat flour did not induce dental caries in either hyposalivated or sham-operated rats, irrespective of infection by S. mutans. Bacteriological examinations at the end of the experiment demonstrated that the total numbers of lactobacilli and staphylococci increased in hyposalivated rats irrespective of the diet given, while the inoculated stain of S. mutans decreased significantly in hyposalivated rats. These findings suggest that some acidogenic microorganisms such as lactobacilli and staphylococci that can utilize sucrose or glucose but not wheat flour may also promote dental caries in hyposalivated rats.

The cariogenicity of Ferrero Milchschnitte and apple was tested in rats using a frequency-controlled feeding machine. Twelve litters of Osborne-Mendel rats orally infected with Streptococcus sobrinus OMZ-176 and Actinomyces viscosus Ny-1 were used. Four treatment groups were tested: (1) cooked starch/sucrose 1:1 as positive control; (2) Ferrero Milchschnitte; (3) apple; (4) gastric intubation only as negative control. Groups 1-3 were additionally fed by gastric intubation with essential nutrients. Rats on Milchschnitte and apple had less fissure and smooth-surface caries than rats on a starch/sucrose diet, but significantly more than the negative controls. The Milchschnitte group exhibited less plaque extent than the positive and the negative control. The apple group showed a higher plaque extent and massively extended erosions on molar surfaces. The CFU means of S. sobrinus were decreasing from treatment 1-4. Although differences between treatments were not significant, they were associated by concomitantly decreasing caries incidence. The test foods were also assessed using intraoral plaque-pH telemetry in 6 human volunteers. Both Milchschnitte and apple were acidogenic in human telemetry. They can therefore not be regarded as safe for teeth.

As part of a major study to identify cariogenic elements of foods, the cariogenic potential of 22 foods relative to sucrose (confectioners' sugar) was determined over six intubation rat caries experiments. Cariogenic potential indices were calculated for each food from sulcal and buccal-lingual caries based on both number and severity. Those foods with the lowest cariogenic potential indices were peanuts, gelatin dessert, corn chips, yoghurt, and bologna; with the highest cariogenic potential indices were sucrose, granola cereal, french fries, bananas, cupcakes, and raisins. There was no simple relationship between food sucrose content and caries. Enhanced cariogenic potential was associated with foods containing approximately 1% or more hydrolyzable starch in combination with sucrose or other sugars.

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 X 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.

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.