Claes-Göran Emilson

EFFECT OF CARIES PREVENTIVE MEASURES IN CHILDREN HIGHLY INFECTED WITH THE BACTERIUM STREPTOCOCCUS MUTANS

The number of Strep. mutans in saliva samples was examined in 101 13-14-year-old children, 53 in a control and 48 in the test group. All in the test group with 2.5 X 10(5) Strep. mutans per ml saliva were treated with 1 per cent chlorhexidine gel, once a day, for 14 days when the number of Strep. mutans was greatly reduced. Saliva samples were then examined in the test group every 4th month and all children with Strep. mutans levels above 2.5 X 10(5) were treated. A few selected children had fissure sealants applied to the occlusal surfaces. After 3 years, the mean number of new carious lesions was 9.6 in the control group and 4.2 in the test group. In the children with 10(6) Strep. mutans at the start of the study, the corresponding figures were 20.8 compared with 3.9. Thus a reduction in caries activity can be achieved by controlled antimicrobial treatment.

Utilization of dental services in relation to socioeconomic and health factors in the middle-aged and elderly Swedish population

The aims of this study were to describe the change in reported time since the latest visit to a dentist between the years 1980/81 and 1988/89 and the reported use of dental services in relation to age, dental state, and socioeconomic and health characteristics in a sample of the Swedish population in 1988/89. The studies are based on interviews by Statistics Sweden about the living conditions. In the investigations in 1980/81, 14,964 inhabitants between 16 and 84 years of age participated, and in 1988/89, 13,309 inhabitants. In all age groups there was a significantly higher frequency of reported visits to a dentist last year in 1988/89 than in 1980/81. In the age group 50-64 years old this figure increased from 54% to 75%, and in the age group 65-84 years old it increased from 26% to 39%. In the investigation in 1988/89 about 75% of the dentulous women in all age groups up to 75 years reported visiting a dentist last year. The relative risk for not visiting a dentist last year, adjusted for age, gender, and dental state, was higher in dentulous subjects with low income and education, not married, not native-born, living in rural areas, smoking, and low social and physical activity. The results of the logistic regression analysis showed that, among the elderly, functional ability and general health factors have lower significance for time since last visit to a dentist than socioeconomic, social support, and life-style factors.

Colonization of Streptococcus mutans and Streptococcus sobrinus Genotypes and Caries Development in Children to Mothers Harboring Both Species

The major route of early acquisition of mutans streptococci in humans is a vertical transmission from mother to child. The purpose of this longitudinal study was to examine the acquisition, distribution and persistence of Streptococcus mutans and Streptococcus sobrinus in children whose mothers harbored both species and to study the caries incidence in relation to colonization of these bacteria. Fifteen mother-child pairs were followed during the child’s first 7 years. Stimulated salivary samples were taken from the mothers and the children. Plaque samples were also collected from the teeth and the tongue of the children. The samples were analyzed by cultivating techniques together with genomic fingerprinting and hybridizing. The caries experience was evaluated on the sampling occasions and retrospectively using the records of caries registrations from the community clinics. During the 7-year period 10 of the 15 children acquired mutans streptococci. Only 4 of them were colonized by both S. mutans and S. sobrinus despite the fact that their mothers harbored both species. In 2 of the children S. sobrinus was found later than S. mutans. A total of 26 genotypes were found in the children and 9 of them were identical to their mothers. New genotypes and a gain-loss pattern were noted especially in the children but also in their mothers. The groups of teeth first positive for the two species were the deciduous molars. The caries experience was low during the study period with 8 children showing no caries.

A 2-year clinical evaluation of sealed noncavitated approximal posterior carious lesions in adolescents

The objective was to evaluate the clinical performance of a therapeutic sealant to arrest the progression of noncavitated approximal posterior carious lesions. The study population comprised 50 adolescents in whom bitewing radiographs had been taken for diagnosis of caries. Approximal noncavitated lesions in premolars and molars (4d–7m) were selected. One group (n=17) had a sealant placed after tooth separation on all enamel lesions. A second group (n=7) received sealant and fluoride varnish in a split-mouth design. A control group (n=26) received a standard fluoride varnish treatment without tooth separation. Follow-up radiographs were taken after 2 years and were analyzed together with the baseline radiographs in a blind study setting. About 93% of the sealed initial carious lesions showed no progression. The corresponding value for the fluoride varnish control group was 88%. In the split-mouth study, 92 and 88% of the surfaces with enamel caries showed no progression after sealant or fluoride varnish treatment, respectively. The difference between the two treatment procedures was not statistically significant. The incidence rate for the transition from enamel caries to dentin caries or fillings was 3.5–3.9 surfaces/100 years in the sealant groups and 5.9–6.1 surfaces/100 years in the fluoride varnish groups. The results show the potential of sealants to act as a noninvasive treatment of early approximal enamel lesions.

The influence of saliva on infection of the human mouth by mutans streptococci

The relationship between oral implantation of Streptococcus mutans IB1600 (serotype c) and Streptococcus sobrinus OMZ65 (serotype g), the aggregating activity of saliva, and its influence on the adherence of these bacterial strains in vitro was examined in seven human subjects. All the saliva samples aggregated strain IB1600 but not strain OMZ65 cells. Whole saliva from subjects with low levels of infection by Strep. mutans aggregated strain IB1600 to a greater degree than did whole saliva from those who were readily infected. Whole saliva from subjects most resistant to infection supported the adsorption of the highest number of either strain IB1600 or OMZ65 to hydroxyapatite surfaces. Thus the ability of whole saliva to aggregate Strep. mutans may influence the ability of these microorganisms to infect the mouth.

Final pH affects the interference capacity of naturally occurring oral Lactobacillus strains against mutans streptococci

OBJECTIVES To establish the effects of three factors: previous caries experience; colonization of Streptococcus mutans; and final pH on autologous lactobacilli-mediated inhibition against a panel of mutans streptococci in young subjects with different caries experiences. DESIGN The inhibition capacity was determined by the use of the agar overlay method and the final pH in culture medium was measured after 20 h. Using a logistic regression model, the risk of having an incomplete lactobacilli-mediated inhibition was calculated. RESULTS All three factors significantly influenced the interference outcome in the order; final pH of the Lactobacillus strains, oral colonization of autologous S. mutans and caries experience. A high risk occurred at a lower pH and at a wider pH range for individuals with previous caries experience and autologous colonization of S. mutans compared with caries-free subjects who were not colonized. At a final pH of 4.0, this risk was approximately eight times higher than that of the latter group. Two mutans Streptococcus strains in the test panel demonstrated high individual predictive values of inhibition mediated by oral lactobacilli. CONCLUSIONS Generation of a low pH either directly via organic acid production and/or production of bacteriocins or metabolites at a low pH may promote mutans Streptococcus growth inhibition, in vitro. Furthermore, a shift of pH range for the risk of incomplete inhibition of mutans streptococci suggests a less effective inhibition at a wider pH range for naturally occurring lactobacilli from individuals with earlier caries experience containing own S. mutans.

Dental Location of Streptococcus mutans and Streptococcus sobrinus in Human: Harboring Both Species

The distribution and prevalence of Streptococcus mutans and Streptococcus sobrinus were determined in plaque samples from the cervical areas of all buccal, lingual and approximal tooth surfaces and from the fissures of all occlusal sites in 40 subjects harboring both species. S. mutans was detected more often and in higher numbers than S. sobrinus. There were more teeth detected with S. mutans only than with S. sobrinus only. Most teeth harbored both of these mutans streptococci species, indicating a positive association. The highest numbers of CFU for both species were detected on the molars, with the lowest incidence on the anterior teeth. The presence of S. mutans was relatively similar on all teeth tested, while the presence of S. sobrinus was relatively higher on the molars compared to the anterior teeth. S. mutans and S. sobrinus were found to colonize the buccal surfaces in almost equal numbers. On all other surfaces, S. mutans was detected more frequently or in higher numbers compared to S. sobrinus. No significant differences could be found in the relative proportions of S. mutans and S. sobrinus between sound, decayed or filled tooth surfaces.

Dental caries and related factors in 88- and 92-year-olds. Cross-sectional and longitudinal comparisons.

Our aim was to compare two groups of 88- and 92-year-olds (n = 92 and n = 40), respectively, with regard to teeth, caries, and salivary and microbial conditions. Oral variables were analyzed in relation to functional capacity and use of cardiovascular agents and psychoactive drugs. Untreated root caries, plaque score, and counts of lactobacilli increased between the ages of 88 and 92 years (P < 0.01). Nine of the 24 longitudinally followed up subjects had lost 1-5 teeth over 4 years, and 17 subjects had developed new caries (DFS). The mean caries increment over 4 years was 1.3 coronal and 3.6 root surfaces, and new DFS per 100 surfaces at risk was 4.3 coronal and 17.5 root surfaces. Plaque score and final pH of buffer capacity increased (P < 0.05 and 0.01, respectively), whereas saliva flow, independent of gender, was unchanged. Use of cardiovascular agents and psychoactive drugs was associated with a deteriorated dental status.

Salivary antimicrobial proteins in patients with Crohn's disease☆

The aim was to study the level of salivary proteins with antimicrobial properties in persons with Crohns disease. Twenty-five patients were recruited, 13 with ongoing symptoms (acute group) and 12 free of clinical signs of the disease at the time of the investigation (nonacute group). A control group matched to the nonacute group was also included in the study. Unstimulated and stimulated whole saliva samples were collected, and the secretion rates estimated. Unstimulated saliva was analyzed for concentrations of total protein, peroxidase, thiocyanate, slgA, lactoferrin, lysozyme, and for specific bacteria aggregation ability. Numbers of mutans streptococci and lactobacilli in saliva were determined, and dental caries status was examined. No differences were found among the groups regarding salivary flow rate, total protein, or any of the antimicrobial proteins. However, three patients with Crohns disease had no detectable slgA in saliva compared with none in the control group. The lactobacillus count and the number of decayed tooth surfaces were higher in the nonacute group than in the control group.

Effects of Sugar Restriction on Streptococcus mutans and Streptococcus sobrinus in Saliva and Dental Plaque

The effect of sugar restriction on the oral levels of mutans streptococci was studied in 20 subjects fulfilling three criteria: (1) having more than 300,000 CFU mutans streptococci/ml saliva, (2) harbouring both Streptococcus mutans and Streptococcus sobrinus in saliva, and (3) eating sugar frequently. The subjects were randomly divided into a test group (n = 12), who were asked to refrain from using sugar-containing foods between meals and to reduce sugar in main meals for 6 weeks, and a control group (n = 8), who did not receive any dietary advice. Saliva and plaque samples were collected at baseline and at 3, 6 and 12 weeks. The results showed that the levels of S. mutans and S. sobrinus decreased in saliva and plaque during the 6-week sugar restriction period. The decrese in mutans streptococci was more pronounced on buccal than on approximal tooth surfaces. Both species seemed to react in a similar way to the sugar restriction in saliva as well as in dental plaque. At the follow-up examination at 12 weeks, i.e. 6 weeks after completing the sugar restriction period, the numbers of S. mutans and S. sobrinus had increased again, but were still lower when compared to the baseline values.