Impact of an oral care subsidization reform on intersectional inequities in self-rated oral health in Sweden.

BACKGROUND: Oral health in Sweden is good at the population level, but seemingly with persisting or increasing inequities over the last decades. In 2008, a major Swedish reform introduced universal partial subsidies to promote preventive care and reduce the treatment cost for patients with extensive care needs. This study aimed to apply an intersectional approach to assess the impact of the 2008 subsidization reform on inequities in self-rated oral health among adults in Sweden over the period 2004-2018. METHODS: Data from 14 national surveys conducted over 2004-2018 were divided into three study periods: pre-reform (2004-2007), early post-reform (2008-2012) and late post-reform (2013-2018). The final study population was 118,650 individuals aged 24-84 years. Inequities in self-rated oral health were examined by intersectional analysis of individual heterogeneity and discriminatory accuracy across 48 intersectional strata defined by gender, age, educational level, income, and immigrant status. RESULTS: Overall, the prevalence of poor self-rated oral health decreased gradually after the reform. Gender-, education- and income-related inequities increased after the reform, but no discernible change was seen for age- or immigration-related inequities. The majority of intersectional strata experienced patterns of persistently or delayed increased inequities following the reform. CONCLUSIONS: Increased inequities in self-rated oral health were found in most intersectional strata following the reform, despite the seemingly positive oral health trends at the population level. Applying an intersectional approach might be particularly relevant for welfare states with overall good oral health outcomes but unsuccessful efforts to reduce inequities.

Characterization and in vitro properties of oral lactobacilli in breastfed infants.

BACKGROUND: Lactobacillus species can contribute positively to general and oral health and are frequently acquired by breastfeeding in infancy. The present study aimed to identify oral lactobacilli in breast and formula-fed 4 month-old infants and to evaluate potential probiotic properties of the dominant Lactobacillus species detected. Saliva and oral swab samples were collected from 133 infants who were enrolled in a longitudinal study (n=240) examining the effect of a new infant formula on child growth and development. Saliva was cultured and Lactobacillus isolates were identified from 16S rRNA gene sequences. Five L. gasseri isolates that differed in 16S rRNA sequence were tested for their ability to inhibit growth of selected oral bacteria and for adhesion to oral tissues. Oral swab samples were analyzed by qPCR for Lactobacillus gasseri. RESULTS: 43 (32.3%) infants were breastfed and 90 (67.7%) were formula-fed with either a standard formula (43 out of 90) or formula supplemented with a milk fat globule membrane (MFGM) fraction (47 out of 90). Lactobacilli were cultured from saliva of 34.1% breastfed infants, but only in 4.7% of the standard and 9.3% of the MFGM supplemented formula-fed infants. L. gasseri was the most prevalent (88% of Lactobacillus positive infants) of six Lactobacillus species detected. L. gasseri isolates inhibited Streptococcus mutans binding to saliva-coated hydroxyapatite, and inhibited growth of S. mutans, Streptococcus sobrinus, Actinomyces naeslundii, Actinomyces oris, Candida albicans and Fusobacterium nucleatum in a concentration dependent fashion. L. gasseri isolates bound to parotid and submandibular saliva, salivary gp340 and MUC7, and purified MFGM, and adhered to epithelial cells. L. gasseri was detected by qPCR in 29.7% of the oral swabs. Breastfed infants had significantly higher mean DNA levels of L. gasseri (2.14 pg/uL) than infants fed the standard (0.363 pg/uL) or MFGM (0.697 pg/uL) formula. CONCLUSIONS: Lactobacilli colonized the oral cavity of breastfed infants significantly more frequently than formula-fed infants. The dominant Lactobacillus was L. gasseri, which was detected at higher levels in breastfed than formula-fed infants and displayed probiotic traits in vitro.

Subtypes of early childhood caries predict future caries experience.

OBJECTIVES: To test whether postulated subtypes of early childhood caries (ECC) are predictive of subsequent caries experience in a population-based cohort of Swedish children. METHODS: The study included children aged between 3 and 5 years at study entry with dental records available for at least 5 years of follow-up. Dental record data were retrieved from the Swedish Quality Registry for Caries and Periodontal disease (SKaPa) for the initial and follow-up visits. Participants who had ECC at study entry were assigned to one of five ECC subtypes (termed classes 1-5) using latent class modelling of tooth surface-level caries experience. Subsequent experience of caries was assessed using the decayed, missing and filled surfaces indices (dmfs/DMFS) at follow-up visits, and compared between ECC subtypes using logistic and negative binomial regression modelling. RESULTS: The study included 128 355 children who had 3 or more dental visits spanning at least 5 years post-baseline. Of these children, 31 919 had caries at the initial visit. Baseline ECC subtype was associated with differences in subsequent disease experience. As an example, 83% of children who had a severe form of ECC at age 5 went on to have caries in the permanent dentition by the end of the study, compared to 51% of children who were caries-free at age 5 (adjusted odds ratio of 4.9 for new disease at their third follow-up). CONCLUSIONS: ECC subtypes assigned at a baseline visit are associated with differences in subsequent caries experience in both primary and permanent teeth. This suggests that the development and future validation of an ECC classification can be used in addition to current prediction tools to help identify children at high risk of developing new caries lesions throughout childhood and adolescence.

Using Oral Microbiota Data to Design a Short Sucrose Intake Index.

Excessive sucrose consumption is associated with numerous health problems, including dental caries, and is considered to play a critical role in shaping the human microbiota. Here, we aimed to confirm the association between sucrose exposure and oral microbiota profile, develop a short food-based index capturing variation among sucrose consumers and validate it against oral microbiota and dental caries in a derivation cohort with 16- to 79-year-old participants (n = 427). Intake and food preferences were recorded by questionnaires and saliva microbiota by 16S rDNA sequencing. Taxonomic similarities clustered participants into five clusters, where one stood out with highest sucrose intake and predicted sugar related metabolic pathways but lowest species diversity in the microbiota. Multivariate modelling of food intake and preferences revealed foods suitable for a sucrose index. This, similarly to sucrose intake, was related to bacterial pattern and caries status. The validity of the sucrose index was replicated in the population-based Gene-Lifestyle Interactions in Dental Endpoints (GLIDE, n = 105,520 Swedish adults) cohort. This suggested that the index captured clinically relevant variation in sucrose intake and that FFQ derived information may be suitable for screening of sucrose intake in the clinic and epidemiological studies, although adjustments to local consumption habits are needed.

Assessment and visualization of phenome-wide causal relationships using genetic data: an application to dental caries and periodontitis.

Hypothesis-free Mendelian randomization studies provide a way to assess the causal relevance of a trait across the human phenome but can be limited by statistical power, sample overlap or complicated by horizontal pleiotropy. The recently described latent causal variable (LCV) approach provides an alternative method for causal inference which might be useful in hypothesis-free experiments across human phenome. We developed an automated pipeline for phenome-wide tests using the LCV approach including steps to estimate partial genetic causality, filter to a meaningful set of estimates, apply correction for multiple testing and then present the findings in a graphical summary termed causal architecture plot. We apply this pipeline to body mass index (BMI) and lipid traits as exemplars of traits where there is strong prior expectation for causal effects, and to dental caries and periodontitis as exemplars of traits where there is a need for causal inference. The results for lipids and BMI suggest that these traits are best viewed as contributing factors on a multitude of traits and conditions, thus providing additional evidence that supports viewing these traits as targets for interventions to improve health. On the other hand, caries and periodontitis are best viewed as a downstream consequence of other traits and diseases rather than a cause of ill health. The automated pipeline is implemented in the Complex-Traits Genetics Virtual Lab ( https://vl.genoma.io ) and results are available in https://view.genoma.io . We propose causal architecture plots based on phenome-wide partial genetic causality estimates as a new way visualizing the overall causal map of the human phenome.

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.

Allelic Variation in Taste Genes Is Associated with Taste and Diet Preferences and Dental Caries.

Taste and diet preferences are complex and influenced by both environmental and host traits while affecting both food selection and associated health outcomes. The present study genotyped 94 single nucleotide polymorphisms (SNPs) in previously reported taste and food intake related genes and assessed associations with taste threshold (TT) and preferred intensity (PT) of sweet, sour and bitter, food preferences, habitual diet intake, and caries status in healthy young Swedish men and women (n = 127). Polymorphisms in the GNAT3, SLC2A4, TAS1R1 and TAS1R2 genes were associated with variation in TT and PT for sweet taste as well as sweet food intake. Increasing PT for sweet was associated with increasing preference and intake of sugary foods. Similarly, increasing TT for sour was associated with increasing intake of sour foods, whereas the associations between food preference/intake and TT/PT for bitter was weak in this study group. Finally, allelic variation in the GNAT3, SLC2A2, SLC2A4, TAS1R1 and TAS1R2 genes was associated with caries status, whereas TT, PT and food preferences were not. It was concluded that variations in taste receptor, glucose transporter and gustducin encoding genes are related to taste perception, food preference and intake as well as the sugar-dependent caries disease.

Effect of xylitol and xylitol-fluoride lozenges on approximal caries development in high-caries-risk children.

AIM: To evaluate the effect of xylitol- and xylitol/fluoride-containing lozenges on approximal caries development in young adolescents with high caries risk. STUDY DESIGN: A 2-year double-blind trial with two parallel arms and a nonrandomized reference group. MATERIAL AND METHODS: One hundred and sixty healthy 10- to 12-year-old children with high caries risk were selected. After informed consent, they were randomly assigned into a xylitol and a xylitol/fluoride group. They were instructed to take two tablets three times a day (total xylitol and fluoride dose 2.5 g and 1.5 mg, respectively). The compliance was checked continuously and scored as good, fair, or poor. A reference no-tablet group was also selected (n = 70) for group comparison. The outcome measure was approximal caries incidence. RESULTS: The dropout rate was 28%, and 41% exhibited a good compliance with the study protocol. No statistically significant differences in caries incidence could be found between the study groups (P > 0.05). Among a subgroup of children who demonstrated good compliance, the mean DeltaDMFSa value was significantly lower in the xylitol/fluoride group compared to the xylitol group, 1.0 +/- 2.3 vs. 3.3 +/- 4.6 (P < 0.05), while no difference could be displayed between any of the study groups and the reference group (P > 0.05). CONCLUSION: The results from this 2-year trial did not support a self-administered regimen of xylitol- or xylitol/fluoride-containing lozenges for the prevention of approximal caries in young adolescents with high caries risk.

Decreased salivary uptake of [14C]-xylitol after a four-week xylitol chewing gum regimen.

PURPOSE: The aims were to evaluate a simple method to disclose a microbial shift in saliva and to investigate the short- and long-term effects of daily use of xylitol-containing chewing gums on mutans streptococci (MS) and [14C]-xylitol uptake in saliva. MATERIALS AND METHODS: In a pilot set-up, saliva samples were collected from 15 healthy adults and the uptake of xylitol was compared with a specific assay determining xylitol-sensitive MS. The main study consisted of 109 schoolchildren (mean age 9.9 years) who volunteered after informed consent. The children were randomly allocated to a test or control group. The control group was given two pellets containing sorbitol and maltitol 3 times daily for 4 weeks and the test group received identical pellets with xylitol as single sweetener (total dose 6.2 g/day). Saliva samples were collected at baseline, after 4 weeks and 6 months after the intervention. The outcome measures were MS and total viable counts, proportion of MS and salivary uptake of [14C]-xylitol. RESULTS: The pilot study disclosed a fair positive correlation (p < 0.05) between the assays. The proportions of MS and salivary xylitol uptake decreased significantly in the xylitol group by 60% and 30% respectively after 4 weeks compared to baseline which was in contrast to the sorbitol/maltitol group (p < 0.05). Six months after the intervention, the outcome measures did not differ significantly from baseline in any of the groups. CONCLUSION: A relatively high daily dose of xylitol could alter salivary microbial composition during the intervention period but no long-term impact was observed.

Caries risk profiles in two-year-old children from northern Sweden.

AIM: To investigate existing caries risk factors in preschool children and to illustrate their caries risk profiles graphically with aid of a computer-based program. MATERIALS AND METHODS: All 2-year-old children from a small town in northern Sweden were invited and 87% (n = 125) accepted to participate. Data was collected with a questionnaire concerning the child's normal diet and sugar consumption. Special care was taken to note the intake of sweet drinks and sugary between-meal products. Questions on general health and medication, toothbrushing frequency with parental help and use of fluorides were also included. The caries prevalence was recorded with mirror and probe and the level of oral mutans streptococci was enumerated with a chair-side technique. The obtained data were computerised in a risk assessment program (Cariogram) and a graphical profile of each child was constructed. RESULTS: The caries prevalence was 6%, and 18% had detectable levels of oral mutans streptococci. The sugar consumption was strikingly high with 82% and 97% having ice cream and sweets once a week or more often. In 22% of the families, toothbrushing with parental help was not a daily routine. Of the children, 51% displayed a low chance (0-20%) of avoiding caries in the future. The frequency of sugar consumption was the most pertinent factor in the children's caries risk profiles. CONCLUSIONS: Half of the subjects exhibited a low chance of avoiding caries in the near future and the strongest single factor was frequent sugar consumption. Thus efforts to limit and reduce the sugar intake in young children are important measures for primary caries prevention.

Oral Microbiota in Infants Fed a Formula Supplemented with Bovine Milk Fat Globule Membranes - A Randomized Controlled Trial.

BACKGROUND: In a recent study, supplementation of infant formula with milk fat globule membranes (MFGM) decreased the incidence of otitis media in infants <6 months of age. OBJECTIVES: The aim of the present study was to characterize the oral microbiota in infants fed MFGM-supplemented formula and compare it to that of infants fed standard formula or breast milk. METHODS: In a prospective double-blinded randomized controlled trial, exclusively formula-fed infants <2 months of age were randomized to be fed experimental formula (EF, n = 80) with reduced energy and protein and supplemented with a bovine MFGM concentrate, or standard formula (SF, n = 80) until 6 months of age. A breast-fed reference (BFR, n = 80) group was also recruited. The oral microbiota was analyzed at 4 (n = 124) and 12 (n = 166) months of age using Illumina MiSeq multiplex sequencing and taxonomic resolution against the HOMD 16S rDNA database of oral bacteria. RESULTS: Species richness in the oral samples did not differ between the EF and SF groups, but partial least square modeling identified a few taxa that were significantly associated with being in either group, e.g. lower level of Moraxella catarrhalis in the EF group. Infants in the BFR group had significantly lower species richness at 4 months of age and their microbiota pattern differed markedly from the formula-fed groups. CONCLUSIONS: Supplementation of infant formula with MFGM yielded moderate effects on the oral microbiome. Moraxella catarrhalis was less prevalent in infants fed EF than in those fed SF and may be associated with the decrease in otitis media seen in the same group.

Dental plaque formation and salivary mutans streptococci in schoolchildren after use of xylitol-containing chewing gum.

OBJECTIVE: The aim of this study was to investigate the effect of a fixed daily dose of xylitol on mutans streptococci in saliva and the amount of visible dental plaque. A second aim was to explore if the possible effects differed between children with and without caries experience. METHODS: The study was designed as a double-blind randomized controlled trial with two parallel arms. All pupils (n=149) in grades 1-6 in a comprehensive school in northern Sweden were invited, and 128 children (mean age=12.7 years) consented to participate. The children were stratified as having caries experience (DMFS/dmfs>or=1) or not before the random allocation to a test or control group. The control group (A) was given two pellets containing sorbitol and maltitol three times daily for 4 weeks, and the test group (B) received corresponding pellets with xylitol as single sweetener (total dose=6.18 g day). Clinical scoring and saliva samples were collected at baseline and immediately after the test period. The outcome measures were visible plaque index, salivary mutans streptococci counts and salivary lactic acid production. RESULTS: The amount of visible plaque was significantly reduced in both groups after 4 weeks (P<0.05). Likewise, the sucrose-induced lactic acid formation in saliva diminished in both groups (P<0.05). The proportion of mutans streptococci decreased significantly in the test group compared to baseline, but not in the control group (P<0.05). The alterations in the test group seemed most prominent among children without previous caries experience. CONCLUSIONS: The results suggest that chewing gum with xylitol or sorbitol/maltitol can reduce the amount of dental plaque and acid production in saliva in schoolchildren, but only the xylitol-containing gum may also interfere with the microbial composition.

Effect of xylitol on mutans streptococci and lactic acid formation in saliva and plaque from adolescents and young adults with fixed orthodontic appliances.

This study aimed to investigate two dose regimens of xylitol-containing tablets on the ecology of dental plaque and saliva during treatment with fixed orthodontic appliances. The study group comprised 56 healthy patients (mean age 15.8 yr) randomly assigned into the following groups: A, (n = 23) two xylitol tablets two times a day (1.7 g xylitol d(-1)) for 18 wk; B, (n = 23) two tablets four times per day (3.4 g xylitol d(-1)) for 18 wk; and C, (n = 10) no tablets. The levels of mutans streptococci (ms) were enumerated in plaque and saliva and the proportion of xylitol-sensitive (X(S)) strains in saliva was determined by autoradiography with [(14)C]-xylitol at baseline and at 6, 12, and 18 wk. The lactic acid formation rate was assessed enzymatically in sucrose-challenged plaque suspensions. A drop in salivary ms levels was found in Group A after 6 wk but not after 12 or 18 wk. The proportion of X(S) ms was decreased after 6 wk in groups A and B and remained so during the experimental period. The lactic acid formation rates decreased slightly ( approximately 10%) in the two xylitol groups compared with baseline. In conclusion, our results showed that although an alteration of ms strains was demonstrated following a regular daily low-dose intake of xylitol, the long-term total ms counts in plaque and saliva as well as plaque acidogenicity remained unchanged.