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Biomedical subjects

L Granath

Publications and source records attributed to L Granath.

At least 19 recordsLinked to original sources
PubMed1997

On the pH-lowering potential of lactobacilli and mutans streptococci from dental plaque related to the prevalence of caries.

The common method used today to identify persons at risk of dental caries is to estimate the numbers of cariogenic bacteria such as lactobacilli and mutans streptococci in saliva or plaque samples taken from the patient. However, the value of these bacterial counts for explaining and predicting individuals at risk of caries has not been powerful enough. Evaluating one virulence factor such as the acidogenicity of these bacteria might increase their explanatory values for caries. Sixty children aged 14-15 yrs participated in this study. Smooth surface caries and restorations were registered and total plaque samples collected. Counts of lactobacilli and mutans streptococci were estimated, and the pH-lowering potential of both bacteria was measured in an adapted glucose broth. The results showed a weak association between dental caries and lactobacilli, but in the subgroup with this bacterium the explanatory value increased to 14% and in the subgroup with a strong pH-lowering potential it was as high as 27%. For mutans streptococci the associations were weak in all groups.

Adolescent↗
PubMed1996

Number of mutans streptococci or lactobacilli in a total dental plaque sample does not explain the variation in caries better than the numbers in stimulated whole saliva.

For practical reasons the numbers of mutans streptococci (MS) and lactobacilli (LB) in plaque are commonly estimated from saliva samples. The saliva counts are considered to be a reasonable indicator of the entire dentition's total microbial load. However, the value of salivary counts for explaining and predicting caries have been found to be low. There was therefore reason to compare the relationships between caries on the one hand and, on the other, the number of MS or LB in plaque and in saliva, respectively, in order to assess their relative merits for explaining the variation in caries, both in a total material and in subgroups with less favourable oral hygiene. Sixty children aged 14-15 years participated in the study. Caries and plaque were registered and the number of MS and LB was estimated in total plaque and in stimulated saliva samples. The results showed that the number of MS or LB in plaque did not explain the variation in caries to a greater degree than did the salivary counts. For both bacteria the explanatory values increased, as expected, in subgroups with less favourable oral hygiene, but not even at this higher level of explanation was there any difference between plaque and saliva. The LB count was a stronger explanatory variable than the MS count. It was concluded that the number of MS and LB, estimated in total plaque as well as in saliva samples, is not a useful tool in prediction.

Adolescent↗
PubMed1996

Anomalies in the permanent dentition and other oral findings in 29 individuals with Laurence-Moon-Bardet-Biedl syndrome.

This paper reports a clinical and roentgenological examination of the teeth, jaws and saliva of 29 Scandinavian individuals with Laurence-Moon-Bardet-Biedl (LMBB) syndrome, whose cardinal signs are retinal dystrophy, polydactyly, obesity, hypogenitalism and mental retardation. All subjects had at least three of these signs, including retinal dystrophy. Compared with normal subjects, the group had statistically significantly higher frequencies of hypodontia, small teeth and short roots. In addition, the saliva showed a buffering capacity higher than normal. In conclusion, there seem to exist disturbances of both dental and skeletal formation in the LMBB syndrome.

Adolescent↗
PubMed1995

Influence of social factors on sugary products behavior in 4-year-old children with regard to dental caries experience and information at child health centers.

The aim was to analyze the steering effects of 15 social factors on sugary products behavior at 4 years of age in 177 children. The parents had in most cases received information on dental health care at child health centers, with due respect to the level of caries among the children, who were classified as 'healthy' (no caries experience) (n = 83) or 'diseased' (caries experience) (n = 84). The parents filled in a mailed diet history form. Only sugary products unsuitable from a cariologic point of view were considered. The products were given scores reflecting the frequency of intake. The social factors were social background, family, information, and conceptual factors. By means of multiple regression analysis, explanatory values of the social variables for sugary products behavior were estimated. For the total material, 13% of the variance was explained by all variables combined. Among the social background factors, 'parents' age' was statistically significant (p < 0.05). Among family factors, 'day-care mainly at home' and 'oldest child' were the most important. All information factors proved to be nonsignificant. Of the conceptual factors, only 'importance of genetic factors' was statistically significant. For the healthy group 26% of the variance was explained by all variables. 'Mother's age', 'importance of genetic factors', and 'oldest child' were statistically significant. For the diseased group all variables were nonsignificant. Explanatory values were negligible. The important conclusions were that very few traditionally conceived social variables seem to influence 4-year-old children's sugar behavior. Parents of children with caries appear to be a heterogeneous group with an irrational behavior.

Attitude to Health↗
PubMed1994

Salivary lactobacilli explain dental caries better than salivary mutants streptococci in 4-5-year-old children.

The present comparative study was undertaken to determine which of the bacteria, lactobacilli (lbc) and mutans streptococci (ms), in saliva better explains the variation of caries in 2728 South African 4-5-yr-old children. Caries was diagnosed according to WHO criteria. For lbc, the Dentocult system was used. The number of ms in stimulated saliva was counted on MSB agar plates. For correction of confounding factors, data on the frequency of intake of sweets were derived from extensive interviews. Oral hygiene was determined according to the simplified debris index of Greene & Vermillion. Simple correlation analyses between dmfs and bacterial counts were done for the total material and for three caries intervals by calculating Spearman's and Pearson's coefficients of correlation. Multivariate regression analyses were done on all intervals to correct for the confounding effects of regular intake of sweets, presence of salivary ms or lbc, and oral hygiene. Of the children, 68% had detectable lbc in the saliva, and 74% had ms. Except for children with more than 6 dmfs, the explanatory values, i.e., percentage of variation in dmfs explained, were higher for the lbc than for ms. Before correction, the values for the total material were 15 vs 6%; for children with caries, 7 vs 5%; for those with 1-6 dmfs, 5 vs 0.4%; and for those with more than 6 dmfs, 0.3 vs 2%. All r-values were reduced after correction, indicating that the confounders explain some of the correlation between dmfs and bacterial count.(ABSTRACT TRUNCATED AT 250 WORDS)

Child, Preschool↗
PubMed1993

Tissue plasminogen activator (t-PA) and placental plasminogen activator inhibitor (PAI-2) in gingival fluid from 8-9-year-old children.

High concentrations of tissue plasminogen activator (t-PA) and placental type plasminogen activator inhibitor (PAI-2) have previously been found in gingival crevicular fluid (GCF) of adults. In the present study, the levels were examined in 16 children aged 8-9 yr. Sampling of GCF was performed with small disks of Millipore-filter. t-PA and PAI-2 were analyzed with enzyme-linked immunosorbent assays with low method errors. The mean concentration of t-PA was slightly higher than in adults, while the mean PAI-2-concentration was slightly lower. An intraindividual study comparing healthy and inflamed sites in the children showed slightly higher concentrations in GCF from inflamed sites. No change was observed in the balance between t-PA and PAI-2.

Age Factors↗
PubMed1993

Prevalence of dental caries in 4- to 5-year-old children partly explained by presence of salivary mutans streptococci.

The correlation between dental caries and the number of oral mutans group streptococci (ms) present has been shown to be weak. The aim of this investigation was to study associations between caries experience (decayed, missing, and filled surfaces [dmfs]) and the number of ms in stimulated saliva, with emphasis on the level of disease and the confounding effect of regular intake of sweets, the presence of salivary lactobacilli, and oral hygiene. In some 2,700 4- to 5-year-old South African children of different ethnic origins, caries was diagnosed on the basis of World Health Organization criteria and saliva samples were analyzed for ms after cultivation on mitis salivarius-bacitracin agar and for lactobacilli by using the Dentocult kit. Oral hygiene was scored on the basis of the Greene and Vermillion simplified debris index, while data on intake of sweets were derived from extensive interviews. Pearson's coefficient of correlation was computed, and multiple regression analysis was performed to correct for confounding factors. The distribution of the children in the eight caries classes was strongly associated with the ms class (P < 0.001), with those in the lower ms classes generally having low dmfs scores and those in the higher ms classes having dmfs scores distributed over the whole range. The r value for the two variables was 0.25 for the total material; this was reduced to 0.18 by correction for confounding factors. The corresponding values for children with caries were 0.21 and 0.17, for those in the 1 to 6 dmfs interval they were 0.07 and 0.03, and for those in the 7 to 81 dmfs interval they were 0.16 and 0.14. The data imply that the explanatory values for ms, those for the lower caries interval not counted, ranged from 6 to 2%. The unexpected results for children with caries might be due to their distribution pattern. It is concluded that there is a need for reevaluation of ms as a risk factor in dental caries.

Candy↗
PubMed1992

Variation of posterior approximal caries incidence with consumption of sweets with regard to other caries-related factors in 15-18-year-olds.

The aim of this study was to analyze the relationships between caries incidence and a number of caries-related factors in 15-18-yr-olds, in order to estimate the explanatory value of consumption of sweets under different conditions. Sixty-nine 18-yr-olds were interviewed about consumption of sweets and other sugar-containing products during the past 3 yr. Data on oral hygiene, salivary counts of mutans streptococci and lactobacilli, salivary flow rate and oral sugar clearance time were collected when the individuals were 15 and 18 yr old. Caries incidence for the 3-yr period was expressed as a percentage of the number of caries-free approximal surfaces of premolars and molars at the age of 15. Simple linear correlations between caries incidence and the different variables showed that lactobacilli count ranked first (r = 0.26), sweets second (r = 0.25), and mutans streptococci count third (r = 0.24). The r value for caries incidence and consumption of sweets increased in subgroups with combinations of poor oral hygiene, a high intake of other sugary products and a low salivary flow rate (r = 0.67-0.70). In conclusion, consumption of sweets should still be considered an important caries-related factor and particularly harmful when oral hygiene is poor and consumption of other sugary products is high.

Adolescent↗
PubMed1992

Sweets and other sugary products tend to be the primary etiologic factors in dental caries.

The aim of this study was to analyze the relationships between caries incidence and each of seven caries-related factors in a group of 15- to 18-yr-olds as well as in single and combined subgroups representing favorable or less favorable fractions of six of the factors. Sixty-nine 18-yr-olds were interviewed about consumption of sweets and other sugar-containing products during the past 3 yr and examined for oral hygiene, salivary counts of mutants streptococci and lactobacilli, salivary flow rate and oral sugar clearance time at the ages of 15 and 18. Simple linear correlations and a stepwise multiple regression analysis were used to compare ranks and explanatory values. The highest correlations were obtained for intake of sweets and intake of other sugary products, with r values increasing from 0.25 and 0.16, respectively, in the total material to 0.70 and 0.67 in less favorable fractions of oral hygiene, salivary flow rate and other sugary products in the former case, sweets in the latter. The stepwise multiple regression analysis revealed that sweets and other sugary products contributed 12 percentage points to the total explanatory value, which was as low as 19%.

Adolescent↗
PubMed1992

Clinical evaluation of preventive and class-I composite resin restorations.

This study was initiated in 1986 in response to increased interest in restorative procedures favoring preservation of tooth substance and in the search for alternatives to dental amalgams. Eighty-seven preventive resin restorations in permanent molars and 35 occlusal composite resin restorations in primary molars (limited size) and 13 in premolars were followed up for 2 years. They were placed by a large number of operators, mainly dental students under supervision, and rated by five calibrated instructors in accordance with an internationally accepted system for the evaluation of the clinical performance of dental materials. One composite resin (Occlusin) was used. A survival model was used to calculate the cumulative theoretical number of successful treatments of children who had dropped out. For none of the 6 clinical variables was the success rate lower than 91%, and only 3 of 26 failures were of a nature requiring remake or correction. The failures occurred, with a few exceptions, during the 1st year of observation. The two types of restoration have thus proved to be efficient treatments fulfilling all reasonable requirements in modern operative dentistry.

Adolescent↗
PubMed1991

Correlations between caries prevalence and potential etiologic factors in large samples of 4-5-yr-old children.

A data base containing information on dental caries, oral hygiene, gingival state, Streptococcus mutans and lactobacillus counts, and salivary flow rate and buffer capacity in some 2800 4-5-yr-old South African children was created in 1984. The children were equally distributed in four groups; rural black, urban black, urban Indian, and urban white. In this study, the data were used for simple linear correlations between all the factors including caries as well as stepwise multiple regression analyses between caries prevalence and the independent factors in each of the four groups. The highest r value obtained in the single correlations was 0.56 for dmfs/lactobacillus count in the white group. The overall pattern of the groups did not vary much. In the stepwise multiple regression analyses, lactobacilli entered first in all groups. S. mutans and oral hygiene interchanged as Nos. 2 and 3, and gingival state or buffer capacity came out as No. 4. The highest percentage of caries variability explained by these regressions was 25%, in the urban black group, while the lowest was 12%, in the indian group. It was concluded that our generally accepted etiologic factors are unsatisfactory to explain variation in caries in observational studies, which among other things might be ascribed to the inadequate way these factors generally are measured or estimated.

Black or African American↗
PubMed1991

Elastic outward bending of loaded buccal and lingual premolar walls in relation to cavity size and form.

The aim was to study effects of the size and form of the occlusal part of Class II cavities on elastic outward bending during loading of buccal and lingual walls, separated by the preparation. Twenty newly extracted caries-free premolars were used. A special arrangement for standardized cavity preparation was set up. In order to obtain accurate measurements of the outward bending of loaded cavity walls, an electronic tensile test device was constructed. Methodologic studies showed an insignificant departure from linearity between between outward bending and load. All deformation was elastic. Correction factors were determined for strain of the apparatus as well as for indentation in the tooth substance. Measurement accuracy was calculated to +/- 0.12 N for force and +/- 0.2 micron for movement. In accordance with statistical principles, a few outlying measurements were discarded. The outward bending of buccal and lingual walls of cavities suitable for conservative restoration with dental amalgam was about 0.15 micron per Newton. Outward bending increased dramatically with exaggerated cavity depth and width. In the light of present knowledge of average chewing forces and tooth contacts in the habitual intercuspal position in young dentate adults, there seems to be little risk of leakage between conservative restorations and cavity walls as a result of elastic outward bending, though the risk certainly does increase with the depth and width of the cavity.

Bicuspid↗
PubMed1989

Correlation between child caries incidence and S. mutans/lactobacilli in saliva after correction for confounding factors.

The correlation between caries incidence and Streptococcus mutans/lactobacilli in saliva was studied in two different age groups, followed from ages 5 to 7 and from 12 to 14. The coefficients of correlation were computed before and after correction for the confounding effect of oral hygiene and the alternative bacteria. The best value for S. mutans was found for the total material in the younger age group (r = 0.24). For lactobacilli the best value was found for the total materials and in the subgroup with less favorable oral hygiene and S. mutans count in the older age group (r = 0.18). The connection between caries incidence and these bacteria was shown to be weak at the individual level, particularly after correction for confounding. The caries differences at group level between subgroups with less favorable and favorable counts of the bacteria were also checked after correction for confounders. The "reduction" figures for S. mutans varied between 23 and 63% and for lactobacilli between 8 and 37% in the two sets of material.

Age Factors↗
PubMed1987

Hard tissue barrier formation in pulpotomized monkey teeth capped with cyanoacrylate or calcium hydroxide for 10 and 60 minutes.

Monkey incisor teeth were pulpotomized in groups of 10. After physiological hemostasis, the pulps of group I were covered with isobutyl cyanoacrylate, and those of groups II and III with calcium hydroxide for 10 and 60 minutes, respectively, whereafter this compound was washed away and the wound surfaces covered with Teflon. In group IV, calcium hydroxide was used as a positive control, and Teflon as a negative control in group V. The animals were killed after 12 weeks and the teeth removed in tissue blocks. The material was processed and evaluated histologically with respect to location and continuity of a hard tissue barrier, type of newly formed hard tissue, state of the pulp, and presence of stainable bacteria in the coronal cavity. Seven of nine teeth in group I showed a hard tissue barrier. The corresponding figure for group II was eight out of 10 teeth. All teeth in groups III and IV had a barrier. The incidence of a continuous barrier increased from group I through group IV, as did the incidence of its location below the level of the original wound surface. The condition of the pulp was related to the presence of bacteria and the continuity of the barrier to the presence of inflammation. There was no bridging in group V. The results support the theory that a low-grade irritation is responsible for the formation of a hard tissue barrier in exposed pulps.

Animals↗
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↗