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Biomedical subjects

D Birkhed

Publications and source records attributed to D Birkhed.

At least 145 records · Page 8Linked to original sources
PubMed1986

Long-term evaluation of root surface caries in periodontally treated patients.

Caries development on exposed root surfaces was evaluated in 31 patients who had been subjected to surgical and/or nonsurgical periodontal treatment 8 years earlier due to advanced chronic periodontitis. Besides assessments for evaluation of the periodontal treatment, a number of examinations and tests were carried out in order to assess variables presumed to influence the root surface caries development. Both statistical and graphical analyses were carried out to test differences between groups of subjects and to evaluate the variables studied as possible risk factors for root surface caries. The variables studied were: salivary lactobacillus count, salivary Streptococcus mutans count, plaque score, salivary secretion rate, salivary buffer effect, oral sugar clearance time, dietary habits and the age of the subject. The final results support previous findings from an initial 4-year period that root surface caries occurs, though to a minor extent, in this patient category demonstrating good or excellent periodontal conditions after periodontal treatment. A positive correlation was found between the baseline and final root surface caries scores. After the second 4-year period, the salivary counts of S. mutans and lactobacilli, the plaque score and the dietary habits differed significantly between groups of subjects who had developed 0 or greater than 5 new DFS %. Root surface caries was far more prevalent when risk values of the variables studied were present than when they were absent. The important variables in this respect differed considerably between the subjects. No single variable was found to be discriminative in all subjects.

Adult↗
PubMed1986

Preeruptive effect of NaF tablets on caries in children from 12 to 17 years of age.

The purpose of this study was to evaluate the preeruptive effect of NaF tablets on caries in proximal surfaces of permanent molars and premolars. The material consisted of 47 subjects who had consumed fluoride tablets for a minimum of 5 yr between 1/2 and 6 yr of age in accordance with recommendations from the National Swedish Board of Health and Welfare (F+-group) and 69 comparable children who had never consumed such tablets (F(-)-group). All had resided since birth in an area with a water fluoride concentration of 0.2 ppm and had been exposed to fluorides in toothpaste, mouthrinse solution and varnish since at least the age of 6. The children were examined by means of bitewing radiographs at the ages of 12, 13, 14 and 17. Two confounding factors, i.e. salivary counts of Streptococcus mutans and lactobacilli, were estimated and used for correction of crude caries differences. The mean values of these factors were higher in the F(-)-group than in the F+-group. The results showed a statistically significantly higher caries prevalence in the F(-)-group compared to the F+-group when the children were 14-yr-old, 4.4 vs. 2.9 DFS, corresponding to a caries reduction of about 34%. After correction for confounding, this was reduced to 24%, representing a non-significant difference of 1.1 DFS but still indicating a preeruptive effect. At the age of 17, the difference in caries prevalence was statistically not significant, 7.1 vs. 5.6 DFS, corresponding to a reduction of 21%. Based on corrected data, this was reduced to 15%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

Caries prevalence, salivary Streptococcus mutans and dietary scores in 13-year-old Swedish schoolchildren.

388 13-yr-old schoolchildren from Karlstad, Sweden, participated. Dental caries experience was expressed as number of decayed (D) and filled (F) tooth surfaces (S), and registered on bite-wing radiographs and obtained from records. Salivary Streptococcus mutans counts were determined by a spatula method. A dietary score was calculated for each individual based on an interview concerning the intake frequency of 23 sugar-containing products. Significantly lower DFS values were found in the group with no detectable S. mutans compared to three of the four groups with salivary S. mutans (P less than 0.01). No differences were found between the DFS values of individuals with high, moderate or low dietary scores. There was no statistically significant association between dietary scores and levels of S. mutans. Among the children with no detectable S. mutans, there were higher DFS-values with increasing intake frequency. No relationship between initial caries lesions, S. mutans and diet was found.

Adolescent↗
PubMed1985

Diagnosis of mild enamel fluorosis in permanent maxillary incisors using two scoring systems.

The main purpose of this study was to compare the diagnosis of mild enamel fluorosis as established by two scoring systems, that of Dean based primarily on quantitative aspects and that of Thylstrup & Fejerskov with a preferentially qualitative approach. A further aim was to study the prevalence of fluorosis in permanent maxillary incisors after intake of fluoride tablets for a minimum of 5 yr between 1/2 and 6 yr of age in accordance with recommendations from the National Swedish Board of Health and Welfare. Maxillary incisors were examined in 118 13-yr-old children; 49 constituted a tablet group and the remaining 69 a control group who had never consumed tablets. Scored according to Dean, the difference in enamel fluorosis between the two groups was statistically not significant at the 5% level, whereas the system of Thylstrup & Fejerskov did give a significant difference. The frequency of fluorosis was substantially lower than that resulting from consumption of drinking water in Uppsala, Sweden, containing 1-1.2 ppm F. A probable relationship was found between the scoring systems, particularly if the Dean score 0.5 ("questionable") was converted to score 1. To ensure correct diagnosis, the tooth surface should be exposed to prolonged drying and apply relevant criteria for the differential diagnosis of disturbances of other origin. The higher sensitivity of Thylstrup & Fejerskov's system relates to score 1, narrow white lines located corresponding to perikymata. Here there seems to be a risk of over- or underdiagnosing. Recommendations are given for epidemiologic surveys and for experimental trials of limited size.

Adolescent↗
PubMed1985

Model for the study of the preeruptive effect of NaF tablets on caries in permanent teeth.

The purpose of this study was to elaborate a model for estimating the caries-reducing effect of a preventive measure with due consideration of background factors. The material comprised 50 children, who had consumed NaF tablets regularly during preschool age, and 76 comparable children who had never consumed NaF tablets. They were all examined at 12 and 13 yr of age. Information on caries and, as confounding factors, dietary habits, oral hygiene and microbiologic variables, was obtained on both occasions. Correlations between the parameters and caries, their discriminating effects and interaction between them were studied. The results showed that correction for confounding diminished the crude caries-reducing effect of NaF tablets. Streptococcus mutans and lactobacilli turned out to be the strongest confounders to discriminate well as single variables and to behave logically in analyses of interaction. Therefore, these factors are recommended in the first place for inclusion in a correction model. If the material is sufficiently large for a further breakdown, oral hygiene (represented by bleeding on probing) could be added. The model will be used in future studies of the preeruptive effect of NaF tablets on caries in permanent teeth in the same population.

Adolescent↗
PubMed1985

Evaluation of a simplified diagnostic aid (Oricult-N) for detection of oral candidoses.

The validity of a simplified diagnostic aid, Oricult-N, for detection of oral candidoses was compared with smears stained according to the periodic acid-Schiff's method. Samples were taken from 80 locations in 36 patients with lesions suspected for candidal infection. There was a statistically significant correlation between the two methods (P less than 0.001).

Adult↗
PubMed1985

Effect of repeated intake of a sugar free fluoride-containing chewing gum on acidogenicity and microbial composition of dental plaque.

In a double blind cross-over study, 20 subjects were given either a sugar free chewing gum containing 0.25 mg fluoride or the same chewing gum without fluoride, eight times a day for 7 days. The pH of 3-day-old plaque was determined before and after each experimental period following a 30-s mouth-rinse with 10 ml 15% sucrose. The pH-decrease was significantly less pronounced after using the fluoride gum than after the placebo gum (P less than 0.001). In a second study, 20 subjects participated in a similar study. In this experiment the acid production activity from sucrose in dental plaque in vitro was determined with the aid of a titration method. In addition, the dental plaque wet weight and the total number of cultivable organisms, Streptococcus mutans and lactobacilli, expressed as the number of colonies per mg plaque, were determined. No significant effect was found on any of these parameters after using the fluoride gum compared to the placebo gum. Thus, the results indicate that slightly elevated levels of fluoride in saliva during daytime, achieved by repeated intake of fluoride gums for 7 days, are sufficient to influence the acidogenicity of dental plaque in vivo.

Chewing Gum↗
PubMed1985

Anaerobic and aerobic metabolism of sorbitol in Streptococcus sanguis and Streptococcus mitior.

Sorbitol-fermenting strains of Streptococcus sanguis and Streptococcus mitior were grown both anaerobically and in the presence of oxygen in a sorbitol-containing complex medium. Washed-cell suspensions were incubated with an excess of sorbitol, and the production of lactate, formate, ethanol, and acetate was analyzed. Moreover, we determined the lactate dehydrogenase and pyruvate formate-lyase activities in cell-free extracts of anaerobically grown cells. The anaerobically grown cells produced lactate, formate, ethanol, and acetate under anaerobic conditions. When these cells were exposed to air, the amounts of formate, ethanol, and acetate were reduced in comparison with those of the strictly anaerobic cells. Cells grown in the presence of oxygen only produced detectable levels of lactate and acetate. Anaerobically grown cells possessed lactate dehydrogenase and pyruvate formate-lyase activities under strictly anaerobic conditions. The level of pyruvate formate-lyase was dramatically reduced when cells were exposed to air, while the level of lactate dehydrogenase was about the same as that under strictly anaerobic conditions. Thus, the results indicate that S. sanguis and S. mitior both metabolize sorbitol differently under anaerobic and aerobic conditions. This difference may depend on the oxygen-sensitivity of the pyruvate formatelyase of these micro-organisms.

Acetates↗
PubMed1985

Microbiological aspects of some caloric sugar substitutes.

Several caloric sugar substitutes are available today, e.g. maltitol, Lycasin, sorbitol, xylitol, palatinit, sorbose, coupling sugar, palatinose, fructose and invert sugar. When evaluating the cariogenicity of these sugar substitutes from a bacteriological point of view, different analytical procedures should be considered. In vitro studies on the capacity of pure oral bacterial strains and dental plaque material to decompose the substitute to acid. Studies on the catabolism of the substitute. Possible adaptation of the oral microflora to metabolize the substitute in vivo as well as in vitro. Studies on any inhibitory effect of the substitute on the microbial activities in dental plaque and on the oral microflora. The capacity of oral bacteria, e.g. Streptococcus mutans, to induce caries in animal experiments should also be considered. Results from such microbiological studies make it possible to classify the caloric sugar substitutes into different groups. The first, most suitable, group seems to consist of xylitol and sorbose. These substitutes are fermented by few oral bacteria and no negative adaptation of the oral flora has been observed. A reducing effect upon dental plaque formation and on acid production from glucose has been reported. A second group consists of maltitol, palatinite, palatinose, sorbitol and Lycasin. These substitutes are fermented by certain groups of organisms within the oral genera Actinomyces, Lactobacillus and Streptococcus. Adaptation of oral bacteria to palatinose and to sorbitol, resulting in a more pronounced acid production, has been observed. No inhibitory effects have been reported. The results from experimental studies suggest that these sugar substitutes have no or little cariogenic action in rodents inoculated with S. mutans.(ABSTRACT TRUNCATED AT 250 WORDS)

Acids↗
PubMed1984

Nutrient intake and health status of lactovegetarians: chemical analyses of diets using the duplicate portion sampling technique.

Six middle-aged lactovegetarians (three men and three women) collected copies of four 24-h diets using the duplicate portion sampling technique. By chemical analyses, the nutrient composition of the lactovegetarian diet was determined in detail and compared with that of a mixed Swedish diet (normal) and a vegan diet (vegan) studied previously. The nutrient composition of the lactovegetarian diet expressed per 1000 kcal represented an average between normal and vegan diets. It was in closer agreement with Swedish recommended dietary allowances than the normal Swedish diet. Thus, the lactovegetarian diet contained 35% of the energy as fat and was rich in polyunsaturated fatty acids, especially linoleic acid, which resulted in a polyunsaturated/saturated fat ratio of 0.6. The lactovegetarian diet had a cholesterol concentration only half of that of a normal diet. Protein content and amino acid composition were well above recommendations. The lactovegetarian diets contained less sucrose than normal and vegan diets, but the sum of the intake of low molecular weight carbohydrates was comparable to normal and vegan diets. Dietary fiber was three times higher than in a normal diet. Essential minerals and trace elements, ie, Ca, Mg, Na, K, Fe, Zn, Cu, Se, satisfied current requirements. The intake of vitamin B12 by the lactovegetarians was around 1.4 micrograms daily, which is below the recommendations. The intake of folates was high, 300 to 400 micrograms daily. The clinical and biochemical investigation of the subjects revealed no signs of nutritional deficiency. Their plasma lipoproteins and the blood pressures were low for their age, in agreement with observations made earlier in a group of vegans.

Animals↗
PubMed1984

Short term fasting and lactovegetarian diet does not affect human saliva.

Forty-two adults, visiting a Swedish health home, participated in the investigation, which included a 6-day period of fasting, followed by a 6-day period with a lactovegetarian diet. The results obtained indicated only a minor and mostly not significant influence on secretion rate, buffer effect, concentration of various electrolytes, and number of lactobacilli and S. mutans of whole saliva.

Adolescent↗