Chapter 10: Probiotic Bacteria and Dental Caries.

The World Health Organization has defined probiotics as "Live microorganisms which, when administered in adequate amounts, confer a health benefit to the host." Traditionally, probiotic microorganisms (mainly Lactobacillus ssp. and Bifidobacterium ssp.) have been used to prevent or treat diseases in the gastrointestinal tract. In the past 20 years, there has been an increased interest in possible oral health effects of probiotics. In vitro studies have shown promising results with growth inhibition of mutans streptococci (MS) and Candida albicans. There are only a few clinical studies with caries development as the primary outcome while more studies have been focusing on control of caries risk factors or so-called surrogate outcomes. Several studies have evaluated the effects of probiotic bacteria on MS in saliva and/or plaque, and a number of probiotic strains show ability to reduce the number of MS. Probiotic bacteria have not been shown to permanently colonize the oral cavity; in early-in-life interventions or in subjects with a mature microbiota. To date investigated strains are transiently present in saliva during and shortly after an intervention. There are eight randomized controlled clinical trials with dental caries as outcome and probiotic strains, administration, duration of the intervention, and target group varied. In a majority of the studies (75%), the interventions resulted in caries reduction in the treatment groups. Although a majority of these studies suggest a caries-preventive effect of probiotic bacteria, more long-term clinical studies are needed in this field before probiotics could be recommended for preventing or treating dental caries.

Urinary Fluoride Excretion after a Single Application of Fluoride Varnish in Preschool Children.

PURPOSE: To assess urinary fluoride excretion after topical application of a commercial fluoride varnish in preschool children. MATERIALS AND METHODS: Twelve healthy children, 2.5-6.0 years of age, were enrolled in a placebo-controlled cross-over trial. After a 5-day run-in period, the morning urine was collected as baseline. One hour after breakfast, 0.1 ml of the active (Fluor Protector S; 7,700 ppm F) or the placebo varnish was applied with a microbrush on the buccal surfaces of the primary teeth. Thereafter, a 6-h urine sample was collected and the fluoride content was determined with an ion-sensitive electrode. The parents supervised toothbrushing with a small-fingernail amount of fluoride toothpaste (1000 ppm) twice daily during the entire experiment. RESULTS: One boy failed to comply with the urinary samplings and was excluded. The mean fluoride concentration in the 6-h urine samples was slightly higher after the active varnish compared with the placebo varnish, but the difference was not statistically significant. Likewise, no statistically significant differences were obtained when the post-treatment concentrations were compared with baseline for the two varnishes. No side-effects or adverse events were reported. CONCLUSION: A single topical treatment with the investigated varnish did not significantly increase the urinary fluoride excretion compared with placebo in preschool children with parallel use of fluoride toothpaste.

The Antisecretory Factor in Plasma and Breast Milk in Breastfeeding Mothers-A Prospective Cohort Study in Sweden.

Inflammation and infection postpartum threaten the mother and her infant. Human milk provides a defense for the infant, but inflammatory complications like mastitis may lead to the cessation of breastfeeding. Antisecretory factor (AF) has a role in the regulation of secretory processes and inflammation. The objective of the study was to describe AF-levels in plasma and breast milk, and in relation to breast complications. Breastfeeding mothers (n = 95) were consecutively recruited at a Well Baby Clinic in Umeå, Sweden. At inclusion four weeks postpartum, samples of venous blood (10 mL) and breast milk (10 mL) were collected. Active AF was analyzed with ELISA using a monoclonal antibody mAb43, and was detected in all samples of plasma and breast milk with a positive correlation (Spearman coefficient = 0.40, p < 0.001; Pearson correlation = 0.34, p < 0.01). High AF-levels in plasma correlated with high AF-levels in breast milk. The results suggest a co-regulation between active AF in plasma and breastmilk, and/or a local regulation of AF in the breast. Further studies are needed to determine the pathways for the activation of AF-levels in breast milk and plasma.

SNX10 gene mutation leading to osteopetrosis with dysfunctional osteoclasts.

Autosomal recessive osteopetrosis (ARO) is a heterogeneous disorder, characterized by defective osteoclastic resorption of bone that results in increased bone density. We have studied nine individuals with an intermediate form of ARO, from the county of Västerbotten in Northern Sweden. All afflicted individuals had an onset in early infancy with optic atrophy, and in four patients anemia was present at diagnosis. Tonsillar herniation, foramen magnum stenosis, and severe osteomyelitis of the jaw were common clinical features. Whole exome sequencing, verified by Sanger sequencing, identified a splice site mutation c.212 + 1 G > T in the SNX10 gene encoding sorting nexin 10. Sequence analysis of the SNX10 transcript in patients revealed activation of a cryptic splice site in intron 4 resulting in a frame shift and a premature stop (p.S66Nfs * 15). Haplotype analysis showed that all cases originated from a single mutational event, and the age of the mutation was estimated to be approximately 950 years. Functional analysis of osteoclast progenitors isolated from peripheral blood of patients revealed that stimulation with receptor activator of nuclear factor kappa-B ligand (RANKL) resulted in a robust formation of large, multinucleated osteoclasts which generated sealing zones; however these osteoclasts exhibited defective ruffled borders and were unable to resorb bone in vitro.

Urinary fluoride excretion after application of fluoride varnish and use of fluoride toothpaste in young children.

BACKGROUND: The efficacy and safety of combined use of topical fluoride products are essential issues that must be monitored. AIM: To assess urinary excretion of fluoride after application of two different dental varnishes containing 2.26% fluoride in 3- to 4-year-old children and to compare the levels with and without parallel use of fluoride toothpaste. DESIGN: Fifteen healthy children were enrolled to a randomized crossover trial that was performed in two parts: Part I with twice-daily tooth brushing with fluoride toothpaste and Part II with twice-daily brushing with a non-fluoride toothpaste. After a 1-week run-in period, 0.1 mL of the two fluoride varnishes (Duraphat and Profluorid Varnish) was topically applied in a randomized order. Baseline and experimental urine was collected during 6-h periods. The fluoride content was determined with an ion-sensitive electrode. RESULTS: There was a statistically significant increase in the 6-h fluoride excretion after application of both experimental varnishes, with and without parallel use of fluoride toothpaste (P < 0.01). When fluoridated toothpaste was used, the mean fluoride excretion was 0.20 mg/6 h after application of Duraphat and 0.29 mg/6 h after application of Profluorid Varnish (P = 0.18). CONCLUSIONS: Topical applications of 0.1 mL of fluoride varnish significantly increased the 6-h fluoride excretion. As some individuals displayed excretion levels exceeding the optimal fluoride exposure, a restricted use of fluoride toothpaste in connection with the varnish applications would decrease fluoride exposure.

A systematic map of systematic reviews in pediatric dentistry--what do we really know?

OBJECTIVES: To identify, appraise and summarize existing knowledge and knowledge gaps in practice-relevant questions in pediatric dentistry. METHODS: A systematic mapping of systematic reviews was undertaken for domains considered important in daily clinical practice. The literature search covered questions in the following domains: behavior management problems/dental anxiety; caries risk assessment and caries detection including radiographic technologies; prevention and non-operative treatment of caries in primary and young permanent teeth; operative treatment of caries in primary and young permanent teeth; prevention and treatment of periodontal disease; management of tooth developmental and mineralization disturbances; prevention and treatment of oral conditions in children with chronic diseases/developmental disturbances/obesity; diagnosis, prevention and treatment of dental erosion and tooth wear; treatment of traumatic injuries in primary and young permanent teeth and cost-effectiveness of these interventions. Abstracts and full text reviews were assessed independently by two reviewers and any differences were solved by consensus. AMSTAR was used to assess the risk of bias of each included systematic review. Reviews judged as having a low or moderate risk of bias were used to formulate existing knowledge and knowledge gaps. RESULTS: Out of 81 systematic reviews meeting the inclusion criteria, 38 were judged to have a low or moderate risk of bias. Half of them concerned caries prevention. The quality of evidence was high for a caries-preventive effect of daily use of fluoride toothpaste and moderate for fissure sealing with resin-based materials. For the rest the quality of evidence for the effects of interventions was low or very low. CONCLUSION: There is an urgent need for primary clinical research of good quality in most clinically-relevant domains in pediatric dentistry.

EDAR-induced hypohidrotic ectodermal dysplasia: a clinical study on signs and symptoms in individuals with a heterozygous c.1072C > T mutation.

BACKGROUND: Mutations in the EDAR-gene cause hypohidrotic ectodermal dysplasia, however, the oral phenotype has been described in a limited number of cases. The aim of the present study was to clinically describe individuals with the c.1072C > T mutation (p. Arg358X) in the EDAR gene with respect to dental signs and saliva secretion, symptoms from other ectodermal structures and to assess orofacial function. METHODS: Individuals in three families living in Sweden, where some members had a known c.1072C > T mutation in the EDAR gene with an autosomal dominant inheritance (AD), were included in a clinical investigation on oral signs and symptoms and self-reported symptoms from other ectodermal structures (n = 37). Confirmation of the c.1072C > T mutation in the EDAR gene were performed by genomic sequencing. Orofacial function was evaluated with NOT-S. RESULTS: The mutation was identified in 17 of 37 family members. The mean number of missing teeth due to agenesis was 10.3 ± 4.1, (range 4-17) in the mutation group and 0.1 ± 0.3, (range 0-1) in the non-mutation group (p < 0.01). All individuals with the mutation were missing the maxillary lateral incisors and one or more of the mandibular incisors; and 81.3% were missing all four. Stimulated saliva secretion was 0.9 ± 0.5 ml/min in the mutation group vs 1.7 ± 0.6 ml/min in the non-mutation group (p < 0.01). Reduced ability to sweat was reported by 82% in the mutation group and by 20% in the non-mutation group (p < 0.01). The mean NOT-S score was 3.0 ± 1.9 (range 0-6) in the mutation group and 1.5 ± 1.1 (range 0-5) in the non-mutation group (p < 0.01). Lisping was present in 56% of individuals in the mutation group. CONCLUSIONS: Individuals with a c.1072C > T mutation in the EDAR-gene displayed a typical pattern of congenitally missing teeth in the frontal area with functional consequences. They therefore have a need for special attention in dental care, both with reference to tooth agenesis and low salivary secretion with an increased risk for caries. Sweating problems were the most frequently reported symptom from other ectodermal structures.

Caries and background factors in Swedish 4-year-old children with special reference to immigrant status.

OBJECTIVE: This study assesses the prevalence of caries and some background factors in 4-year-old children in the city of Umeå, northern Sweden, and compares this with data from earlier studies to reveal changes over time. MATERIALS AND METHODS: Children from the catchment areas of three Public Dental Health Service clinics in Umeå (n = 224) born during the third quarter of 2008 were invited to undergo a clinical dental examination. Decayed surfaces (including both dentine and enamel, except for enamel lesions on buccal and lingual surfaces), missing and filled surfaces (dmfs) were recorded using the same methods and criteria as in a series of earlier studies performed between 1980-2007. Background data were collected in a case-history and a questionnaire. Results. The proportion of children with caries significantly decreased from 2007 (38%) to 2012 (22%) (p < 0.05). In addition, the distribution of dmfs differed significantly between these years (p < 0.05). More immigrant children had caries (42%) than non-immigrant children (15%) (p < 0.05). For children with caries, there were no significant changes in the distribution of dmfs between 1980-2012 (p > 0.05). An immigrant background was associated with a lower frequency of tooth brushing and a higher intake of ice cream, sweets and chocolate drinks (p < 0.05). CONCLUSION: Although the proportion of children with caries declined between 2007-2012, this decline was limited to non-immigrant children. Since 1980 the distribution of dmfs remained unchanged among children with caries. More research on interventions for changing oral health behaviours is needed, specifically for immigrant children.

Palatal height and dental arch dimensions in Turner syndrome karyotypes.

The aim of this project was to study the impact from Turner syndrome (TS) karyotype and age on dental arch morphology and palatal height and to compare the variables in TS with reference data from non-TS females with normal occlusion. Plaster casts from 76 females with TS (6-50 years) were analysed with respect to dentoalveolar arch dimensions and palatal height. The TS females were divided into the karyotype categories: i) 45,X ii) 45,X/46,XX iii) isochromosome, and iv) other. The 45,X/46,XX karyotype exhibited fewer statistically significant variables differing from the reference group compared with other karyotypes. TS females showed increased dentoalveolar depths, decreased maxillary but increased mandibular width, decreased posterior segments, and decreased mandibular circumference compared with the reference group. In opposition to previous reports, the palatal height did not differ compared with non-TS females. Age had an impact on nine of the variables. We conclude that the present dental arch deviations are reflecting the high frequency of malocclusions reported in TS and the subsequent need for orthodontic treatment, which might possibly be lower in the 45,X/46,XX karyotype. The palatal height did not differ from the reference group, but instead the narrow maxilla might contribute to an illusion of a higher palate. We therefore suggest using the nomination 'narrow palatal vault' instead of the commonly used term 'high palatal vault'.

45,X/46,XX karyotype mitigates the aberrant craniofacial morphology in Turner syndrome.

The aim of this project was to study the impact on craniofacial morphology from Turner syndrome (TS) karyotype, number of intact X chromosomal p-arms, and age as well as to compare craniofacial morphology in TS with healthy females. Lateral radiographs from 108 females with TS, ranging from 5.4 to 61.6 years, were analysed. The TS females were divided into four karyotype groups: 1. monosomy (45,X), 2. mosaic (45,X/46,XX), 3. isochromosome, and 4. other, as well as according to the number of intact X chromosomal p-arms. The karyotype was found to have an impact on craniofacial growth, where the mosaic group, with presence of 46,XX cell lines, seems to exhibit less mandibular retrognathism as well as fewer statistically significant differences compared to the reference group than the 45,X karyotype. Isochromosomes had more significant differences versus the reference group than 45,X/46,XX but fewer than 45,X. To our knowledge, this is the first time the 45,X/46,XX and isochromosome karyotypes are divided into separate groups studying craniofacial morphology. Impact from p-arm was found on both maxillary and mandibular length. Compared to healthy females, TS expressed a shorter posterior and flattened cranial base, retrognathic, short and posteriorly rotated maxilla and mandible, increased height of ramus, and relatively shorter posterior facial height. The impact of age was found mainly on mandibular morphology since mandibular retrognathism and length were more discrepant in older TS females than younger.

Isolated oligodontia associated with mutations in EDARADD, AXIN2, MSX1, and PAX9 genes.

Oligodontia is defined as the congenital lack of six or more permanent teeth, excluding third molars. Oligodontia as well as hypodontia (lack of one or more permanent teeth) are highly heritable conditions associated with mutations in the AXIN2, MSX1, PAX9, EDA, and EDAR genes. Here we define the prevalence of mutations in the AXIN2, MSX1, PAX9, EDA, and EDAR genes, and the novel candidate gene EDARADD in a cohort of 93 Swedish probands with non-syndromic, isolated oligodontia. Mutation screening was performed using denaturing gradient gel electrophoresis and DNA sequence analysis. Analyses of the coding sequences of the six genes showed sequence alterations predicted to be damaging or potentially damaging in ten of 93 probands (10.8%). Mutations were identified in the EDARADD (n = 1), AXIN2 (n = 3), MSX1 (n = 2), and PAX9 (n = 4) genes, respectively. None of the 10 probands with mutations had other self-reported symptoms from ectodermal tissues. The oral parameters were similar when comparing individuals with and without mutations but a family history of oligodontia was three times more frequent for probands with mutations. EDARADD mutations have previously been reported in a few families segregating hypohidrotic ectodermal dysplasia and this is, to our knowledge, the first report of an EDARADD mutation associated with isolated oligodontia.

Co-aggregation and growth inhibition of probiotic lactobacilli and clinical isolates of mutans streptococci: an in vitro study.

OBJECTIVE: Co-aggregation and growth inhibition abilities of probiotic bacteria may play a key role in their interference with the oral biofilm. The aim was to investigate the in vitro ability of selected commercial probiotic lactobacilli to co-aggregate and inhibit growth of oral mutans steptococci isolated from adults with contrasting levels of caries. MATERIALS AND METHODS: Mutans streptococci (MS) strains were isolated from caries-free (n = 3) and caries-susceptible (n = 5) young adults and processed with eight commercial probiotic lactobacilli strains. One laboratory reference strain (S. mutans Ingbritt) was selected as control. Co-aggregation was determined spectrophotometrically and growth inhibition was assessed with the agar overlay technique. RESULTS: All probiotic lactobacilli showed an ability to co-aggregate with the isolated MS strains. Statistically significant differences (p < 0.05) were found between strains from different individuals when compared with the reference strain. The selected lactobacilli inhibited MS growth, but the ability varied between the strains and was clearly related to pH. No differences were observed between the different MS strains from caries-free and caries-susceptible individuals. CONCLUSIONS: The selected lactobacilli displayed co-aggregation activity and inhibited growth of clinical mutans streptococci. The growth inhibition was strain-specific and dependent on pH and cell concentration. The findings indicate that the outcome of lactobacilli-derived probiotic therapy might vary between individuals and depend on the specific strain used.

Tooth-brushing behaviour in 6-12 year olds.

BACKGROUND: A common clinical finding is that many schoolchildren display a nonacceptable oral hygiene. AIM: To evaluate the tooth-brushing behaviour in children aged 6-12 years. DESIGN: The study used a cross-sectional descriptive design. Children aged 6, 8, 10, and 12 years in an elementary school in a middle class area in Umeå, a city in northern Sweden, were invited and 82 (82%) consented. Visible plaque on buccal surfaces of incisors and canines was recorded from photographs of the participant's teeth before and after brushing using the scores of the Green and Vermillion Oral Hygiene Index. Brushing technique was recorded with a video camera. A questionnaire was used to collect data about oral hygiene habits at home. RESULTS: The ratio between the sum of plaque scores after and before brushing was statistically significantly higher in the 6-year-old group compared with the 10-year olds, (P < 0.05). There was a negative correlation between time spent for brushing and the ratio between the sum of plaque scores after and before brushing (r = -0.31, P < 0.01). The lowest correlation was displayed in the youngest age group (r = 0.07, P > 0.05). Six-year olds spent statistically significantly less time for brushing than older children (P < 0.05). CONCLUSION: Plaque removal from buccal surfaces from brushing was poor and averaged 19% for 6-year olds and 30% for older children. The results of brushing for children aged 8-12 years could benefit from increasing tooth-brushing time. Children could be given an increasing responsibility from 7 to 8 year of age but parental help is motivated up to 10 years of age.

Growth inhibition of oral mutans streptococci and candida by commercial probiotic lactobacilli--an in vitro study.

BACKGROUND: Probiotic bacteria are suggested to play a role in the maintenance of oral health. Such health promoting bacteria are added to different commercial probiotic products. The aim of the study was to investigate the ability of a selection of lactobacilli strains, used in commercially available probiotic products, to inhibit growth of oral mutans streptococci and C. albicans in vitro. METHODS: Eight probiotic lactobacilli strains were tested for growth inhibition on three reference strains and two clinical isolates of mutans streptococci as well as two reference strains and three clinical isolates of Candida albicans with an agar overlay method. RESULTS: At concentrations ranging from 109 to 105 CFU/ml, all lactobacilli strains inhibited the growth of the mutans streptococci completely with the exception of L. acidophilus La5 that executed only a slight inhibition of some strains at concentrations corresponding to 107 and 105 CFU/ml. At the lowest cell concentration (103 CFU/ml), only L. plantarum 299v and L. plantarum 931 displayed a total growth inhibition while a slight inhibition was seen for all five mutans streptococci strains by L. rhamnosus LB21, L. paracasei F19, L. reuteri PTA 5289 and L. reuteri ATCC 55730. All the tested lactobacilli strains reduced candida growth but the effect was generally weaker than for mutans streptococci. The two L. plantarum strains and L. reuteri ATCC 55730 displayed the strongest inhibition on Candida albicans. No significant differences were observed between the reference strains and the clinical isolates. CONCLUSION: The selected probiotic strains showed a significant but somewhat varying ability to inhibit growth of oral mutans streptococci and Candida albicans in vitro.

Use of radiography in public dental care for children and adolescents in northern Sweden.

UNLABELLED: The primary aims were to investigate the total number of radiographs and the reason for dental radiography in children and adolescents in the Public Dental Health Service. Secondary aims were to study the influence of caries experience and orthodontic treatment on the number of radiographs. For this retrospective study, 544 adolescents regularly attending three Public Dental Health clinics in the county of Västerbotten, northern Sweden were selected. The number of radiographs exposed each year from 3 to 19 years of age was registered. Information on reason for the radiographic examination was extracted from dental records as well as the caries experience at 19 years of age. The attrition rate was 7% due to incomplete data. The total mean number of radiographs exposed was 23+/-6 of which 1+/-2 were extra-oral radiographs. Bitewing radiographs for caries registration constituted 87% of the intra-oral radiographs with a mean number of 19+/-4 exposures. There was a statistically significant difference (p<0.01) between subjects with caries experience (20+/-4) and those with no caries (16+/-4). No gender-related differences were displayed. During preschool ages, bitewing radiographs were taken in less than 10% of the children. Children treated at specialist clinics in orthodontics displayed higher number of radiographic examinations than non-referred children (p<0.01). CONCLUSION: A mean of 23 radiographs were exposed and bitewings for caries detection were the most common radiographic examination. Fewer bitewing radiographs were exposed in caries-free subjects over time but its use during the preschool ages was low. Orthodontics treatment increased the frequency of radiography significantly.

Orofacial dysfunction in ectodermal dysplasias measured using the Nordic Orofacial Test-Screening protocol.

OBJECTIVE: To screen orofacial function in people with various ectodermal dysplasia (ED) syndromes and compare with a healthy reference sample. MATERIAL AND METHODS: The ED group comprised 46 individuals (30 M and 16 F; mean age 14.5 years, range 3-55). Thirty-two had hypohidrotic ED, while 14 had other ED syndromes. The reference sample comprised 52 healthy individuals (22 M and 30 F; mean age 24.9 years, range 3-55). Orofacial function was screened using the Nordic Orofacial Test-Screening (NOT-S) protocol containing 12 orofacial function domains (maximum score 12 points). RESULTS: The total NOT-S score was higher in the ED group than in the healthy group (mean 3.5 vs. 0.4; p<0.001). The dysfunctions most frequently recorded in the subjects with ED occurred in the domains chewing and swallowing (82.6%), dryness of the mouth (45.7%), and speech (43.5%). Those with other ED syndromes scored non-significantly higher than those with hypohidrotic ED (mean 4.6 vs. 3.0; p>0.05). CONCLUSIONS: Individuals with ED scored higher than a healthy reference sample in all NOT-S domains, especially in the chewing and swallowing, dryness of the mouth, and speech domains. Orofacial function areas and treatment and training outcomes need to be more closely evaluated and monitored.

Coaggregation between probiotic bacteria and caries-associated strains: an in vitro study.

OBJECTIVE: To evaluate the in vitro abilities of probiotic bacteria derived from consumer products to coaggregate with caries-associated mutans streptococci. MATERIAL AND METHODS: Six lactobacillus strains (L. acidophilus (CCUG 5917), L. plantarum 299v, L. rhamnosus GG and LB21, L. paracasei F19, L. reuteri PTA5289) were cultivated under anaerobic conditions at 37°C in Man Rogosa Sharpe (MSB) broth for 24 h. Four strains of human streptococci (S. mutans Ingbritt, S. mutans (ATCC 25175), S. mutans GS-5, S. sobrinus (ATCC 33478) were similarly grown in Brain Heart Infusion (BHI) broth. A gastrointestinal pathogen (Escherichia coli) was aerobically cultivated on BHI broth as a positive control. After incubation, the bacteria were aerobically harvested, washed, and suspended in 10 mmol/l phosphate-buffered saline (pH 7.2). The probiotic strains were characterized with the API 50 CH system to confirm their identity. Coaggregation was determined by spectrophotometry in mixtures and bacterial suspensions alone after 1, 2, 4, and 24 h and expressed as the aggregation ratio (%). RESULTS: All probiotic strains showed coaggregation abilities with the oral pathogens and the results were strain specific and dependent on time. S. mutans GS-5 exhibited a significantly higher ability to coaggregate with all the probiotic strains than the other mutans streptococci and E. coli. The differences among the probiotic strains were modest with L. acidophilus being the most prone and L. rhamnosus LB21 the least prone to coaggregate with the oral streptococci. CONCLUSIONS: The results demonstrated different abilities of lactobacilli-derived probiotic bacteria to coaggregate with selected oral streptococci. Aggregation assays may be a useful complement for screening of probiotic candidates with possible anti-caries properties.

Validation of an age-modified caries risk assessment program (Cariogram) in preschool children.

OBJECTIVES: (i) To validate caries risk profiles assessed with a computer program against actual caries development in preschool children, (ii) to study the possible impact of a preventive program on the risk profiles, and (iii) to compare the individual risk profiles longitudinally. MATERIAL AND METHODS: Caries risk was assessed in 125 two-year-old children invited to participate in a 2-year caries-preventive trial with xylitol tablets. At 7 years of age, 103 were available for follow-up, 48 from the former intervention group and 55 from the control group. At baseline and after 5 years, 7 variables associated with caries were collected through clinical examinations and questionnaires, and scored and computed with a risk assessment program (Cariogram). RESULTS: Children assessed as having a "low chance (0-20%) of avoiding caries" had significantly higher caries at 7 years of age compared to children with a lower risk in the control group (p<0.05) but not in the intervention group. Overall predictive accuracy and precision, however, were moderate in both groups. Less than half of the children remained in the same risk category at both ages, despite a largely unchanged consumption pattern of sugar. The majority of the children who changed category displayed a lowered risk at 7 years. The intervention program seemed to impair the predictive abilities of Cariogram. CONCLUSION: A modified Cariogram applied on preschool children was not particularly useful in identifying high caries risk patients in a low-caries community.

Short-term effect of chewing gums containing probiotic Lactobacillus reuteri on the levels of inflammatory mediators in gingival crevicular fluid.

OBJECTIVE: To investigate the effect of a chewing gum containing probiotic bacteria on gingival inflammation and the levels of selected inflammatory mediators in gingival crevicular fluid (GCF). MATERIAL AND METHODS: Forty-two healthy adults with moderate levels of gingival inflammation entered a double-blind placebo-controlled study design. The subjects were randomly assigned to one of three parallel arms: Group A/P was given one active and one placebo gum daily, Group A/A received two active chewing gums, and Group P/P two placebo gums. The chewing gums contained two strains of Lactobacillus reuteri: ATCC 55730 and ATCC PTA 5289 (1 x 10(8) CFU/gum, respectively). The subjects were instructed to chew the gums for 10 min over the course of 2 weeks. Bleeding on probing (BOP) and GCF sampling were conducted at baseline and after 1, 2 and 4 weeks. The levels of IL-1beta, TNF-alpha, IL-6, IL-8 and IL-10 were determined using luminex technology and multiplex immunoassay kits. RESULTS: BOP improved and GCF volume decreased in all groups during the chewing period, but the results were statistically significant (p<0.05) only in Groups A/P and A/A. The levels of TNF-alpha and IL-8 decreased significantly (p<0.05) in Group A/A compared with baseline after 1 and 2 weeks, respectively. A non-significant decreasing tendency was also observed concerning IL-1beta during the chewing period. The levels of IL-6 and IL-10 were unaffected in all groups after 1 and 2 weeks. CONCLUSIONS: The reduction of pro-inflammatory cytokines in GCF may be proof of principle for the probiotic approach combating inflammation in the oral cavity.

Caries prevalence and background factors in Swedish 4-year-old children - a 40-year perspective.

BACKGROUND: Periodic and well-controlled studies of caries and background factors are important for organizing dental care and how prevention should be addressed. AIMS: The aims of this study were to compare data on caries prevalence and background factors in 4-year-old children from 2007 with data collected periodically between 1967 and 2002 with the same methods and criteria, and to compare immigrant and non-immigrant children concerning caries prevalence and background factors. DESIGN: A cross-sectional study in 4-year-old children living in Umeå, northern Sweden (n = 218), was performed. Caries recordings included both cavitated and non-cavitated caries lesion, and bite-wing radiographs were used on indications. Data on oral hygiene, use of fluorides, general health, and medication and sugar consumption were collected using the same questions and questionnaire as in the previous studies. RESULTS: In 2007, 38% of the children displayed caries compared to 46% in 2002. The distribution of decayed, missing, or filled surfaces-primary teeth values was statistically significantly different in 2007 compared to 2002 (P < 0.05). The intake frequency of sugary between-meal products was generally lower, and toothbrushing frequency was higher in 2007 compared with data from the 2002 study. In children with immigrant background, the frequency of toothbrushing was statistically significantly lower, and snacking was more common (P < 0.05). Sixteen per cent had immigrant background and 59% had caries compared to 32% in the rest of the cohort (P < 0.01). CONCLUSION: Important changes in caries prevalence of 4-year-old children have taken place since 2002 concurrently with a decreased intake of sugary between-meal products and increased toothbrushing frequency. Immigrant background had a significant association with caries prevalence in 2007.