Xylitol, classified as a natural sugar substitute, has for about 35 years been known as an agent that may act against caries. The mechanism of action; how it inhibits mutans streptococci (MS) and the clinical dose-response relationship are not however fully investigated. The general aim of the investigations was to evaluate the effect of xylitol on oral ecology in children and adolescents. A series of experimental and controlled clinical trials were performed in which samples of saliva and plaque was collected and analysed with respect to xylitol content, pH, microbial composition and lactic acid production. In paper I, significantly reduced proportions of xylitol-sensitive MS in saliva were demonstrated after 18 weeks of regular use of two dose regimens of xylitol-containing tablets (1.7g and 3.4g xylitol/day) but the acidogenicity in dental plaque was not affected. In paper II, the effect on interdental plaque-pH of two different single dose intakes (2.0g and 6.0g) of xylitol was evaluated. The higher xylitol dose counteracted the pH-drop significantly (p<0.05) when the chewing was followed by a sucrose rinse while the lower dose did not differ from the control. In paper III, the xylitol concentrations in saliva after use of different common xylitol-containing products (0.1g-1.3g) were investigated. Statistically significant elevations of salivary xylitol levels were demonstrated for all products during the first 8-16 min when compared with baseline (p<0.05) but the individual variation was considerable. In samples of supragingival dental plaque, a high dose rinse (6.0g) increased the xylitol concentrations for a longer period (>30 min) than a low dose rinse (2.0g). In paper IV, it was demonstrated that 6.0g of xylitol in chewing gums, every day in 4 weeks, gave significantly less visible plaque and a significantly reduced sucrose-induced lactic acid formation (p<0.05) in saliva. Furthermore, the proportion of MS decreased significantly (p<0.05) compared to baseline. In paper V, the salivary uptake of [14C]-xylitol was compared with a specific assay determining xylitol-sensitive MS and a fair positive correlation (p<0.05) between the two assays was found. In a controlled trial, the proportions of MS and the salivary xylitol uptake decreased significantly (p<0.05) in the xylitol gum test group after 4 weeks compared to baseline which was in contrast to the control gum group. No serious adverse effects were reported in any of the investigations. The main conclusions from this thesis were: a) various xylitol-containing products increased the xylitol levels in saliva and plaque, b) 6.0g of xylitol could counteract the interdental pH-drop after sugar consumption and reduce lactic acid formation in saliva c) a daily dose of 6.0g xylitol reduced the amount of visible plaque and altered the salivary microbial composition, d) a transient shift of MS strains in saliva was demonstrated during periods of regular intake of xylitol products but no long-term impact was found after its termination. The relatively high amount of xylitol needed for a beneficial effect on the oral ecology calls for a further development of effective and safe routes for administration.

The general aim of this thesis was to broaden our knowledge of the signs and symptoms, genetics, and outcomes of dental implant treatment in individuals with oligodontia or ectodermal dysplasia. Article I is a population-based study in three Swedish counties of 162 individuals with oligodontia, which was a prevalence of 0.09%. The intent was to explore ways for dentists to assess symptoms from other ectodermal structures than teeth through a clinical interview and chair-side analyses. Thirty per cent had low salivary secretion rates while only 11% with no known syndrome reported symptoms from hair, nails, or sweat glands. These are, together with teeth, the ectodermal structures on which it is proposed that a clinical diagnosis of ectodermal dysplasia (ED) be based. Article II screened 93 probands with oligodontia for mutations in six genes known to cause oligodontia and hypohidrotic ED. Sequence alterations predicted to be damaging or potentially damaging were revealed in the AXIN2, MSX1, PAX9, and EDARADD genes in 14 (15%) of the probands. All mutations but one were novel. For the first time, EDARADD mutations were shown to cause isolated oligodontia. No individual who had reported ectodermal symptoms from hair, nails, or sweat glands had a mutation. Article III assessed orofacial function in individuals with different types of EDs using the Nordic Orofacial Test-Screening (NOT-S) protocol. Individuals with ED scored significantly higher in orofacial dysfunction than a healthy reference sample, especially in the Chewing and swallowing, Dryness of the mouth, and Speech domains. Article IV surveyed treatment outcome of dental implants in Swedish children up to age 16 years. In a 20-year period, only 26 patients were treated, 5 of whom had hypohidrotic ED and anodontia of the mandible. Individuals with ED had 64% failed implants compared to 6% among subjects with teeth missing due to trauma or agenesis. The main conclusions of this thesis were that (i) a check of whether one or more permanent incisors are missing will identify 65% of individuals with oligodontia and 84% of individuals missing nine teeth or more, (ii) evaluation of salivary secretion is indicated in children with oligodontia, (iii) a majority of individuals with oligodontia did not report other abnormal ectodermal organ function besides teeth, (iv) no clinical indicator discriminated between individuals with and without mutations in the tested genes, and more unidentified genes are involved in tooth morphogenesis, (v) EDARADD mutations are associated with isolated oligodontia, (vi) evaluation of orofacial function is indicated in individuals with ED, and many individuals with ED would benefit from orofacial skills training, (vii) dental implant placement is a rare treatment modality in children, (viii) individuals with hypohidrotic ED seem to present special challenges due to structural as well as direct effects of the mutations on bone, which seem to compromise osseointegration, (ix) central registers on signs and symptoms in individuals with rare disorders would help establish prevalences of various diagnoses and define treatment needs, and (x) quality registers for monitoring treatment outcomes of dental implants would promote early detection of risks and side-effects in individuals with rare disorders.

Congenital heart disease (CHD) is one of the most common congenital anomalies with an incidence of approximately 8–10 cases per 1000 live births. Technical development and continuing improvement in surgical methods have led to early interventions and an increased survival and consequently also a new group of patients in dentistry. The general aim of this thesis was to study the caries prevalence and some possible background factors in children with complex CHD.Paper I examined the caries prevalence in 41 children with complex CHD and 41 healthy age- and gender-matched controls. CHD children had higher dmfs-values 5.2 ± 7.0 vs. 2.2 ± 3.5 in the controls (p < 0.05). CHD children on digoxin medication had higher dmfs values 10.1 ± 8.5 vs. 3.7 ± 5.3 in the other CHD children (p < 0.05). CHD children had received more fluoride varnish treatments and fluoride tablets (p < 0.01).Paper II investigated attitudes and experiences of dental health information and advice, dental care, and service in 33 parents of children with complex CHD and 33 parents of age- and gender-matched controls. Differences were displayed in the professional group that provided the parents with dental health information and advice, attitudes to reception at the dental clinic, and experience of sedation before operative dental treatment (p < 0.05).Paper III examined 183 Swedish general dentists’ experiences of and attitudes to dental care for children with CHD. Eighteen % of the dentists had received special education or information to treat children with CHD, while almost half of the dentists had one or more patients with CHD and a majority of them stated that their CHD patients had a caries problem. The dentists had a different opinion regarding the provision of dental treatment for children with CHD compared to the current situation (p < 0.001).Paper IV studied salivary secretion, salivary buffering capacity, viable count of bacteria (TVC), mutans streptococci (MS) and lactobacilli (LBC), calcium, chloride, magnesium, potassium, sodium, and IgA in 24 children on heart failure medication and 24 healthy controls. Seven children (29 %) had stimulated secretions below 0.5 ml/min compared to no child among the controls (p < 0.01). TVC were 1.4 × 106 ± 1.2 × 107 in the cardiac group vs. 2.7 × 106 ± 2.9 × 107 in the control group (p < 0.05). MS ratio of TVC constituted 0.11 ± 0.35 % vs. 0.01 ± 0.02 % for the controls (p > 0.05).Paper V studied the endogenous pH and titratable acidity and dissolution of calcium and phosphate from dental hard tissues by 13 pharmaceutical preparations used in paediatric cardiology. Six of the preparations had an endogenous pH below the critical value for enamel dissolution.It is concluded that (i) children with complex CHD had a higher caries experience in the primary dentition than healthy matched controls, (ii) children on digoxin medication had a higher caries experience than other children with complex CHD, (iii) children with complex CHD had received more caries prevention than healthy controls, (iv) parents of children with complex CHD were less satisfied with the reception and care they received than parents of healthy children, (v) general dentists had a different opinion regarding the provision of dental treatment to children with CHD compared to the current situation (vi) children on heart failure medication can have a low saliva secretion, (vii) pharmaceutical preparations used on long-term basis in paediatric cardiology may pose a hazardous threat to dental hard tissues due to their acidity.

Övervikt och fetma håller på att utvecklas till ett globalt folkhälsoproblem. År 2010 fanns det fler än 43 miljoner överviktiga barn (under fem års ålder) i världen. Syftet med denna litteraturstudie var att ta reda på om den orala hälsan påverkas hos barn med övervikt. Författarna valde begränsningen barn i åldrarna 2-19 år, och studien utfördes i form av en allmän litteraturstudie. Materialet samlades in genom sökning i de medicinska databaserna PubMed och Science Direct. Resultatet är baserat på en sammanställning av sjutton vetenskapliga artiklar. Ett flertal studier har funnit ett samband mellan ökad kariesförekomst hos barn med övervikt jämfört med barn med normalvikt. Ett fåtal studier har påvisat en association mellan övervikt hos barn och mindre kariesförekomst jämfört med barn med normalvikt. Övervikt hos barn kan leda till tidig tanderuption samt en ökad risk för utveckling av parodontit efter 16 års ålder. Mer forskning krävs för att fastställa om det finns ett samband mellan övervikt hos barn och orala hälsotillstånd. Det är viktigt för tandläkare och tandhygienister att vara uppmärksamma på barnpatienter med övervikt då de kan ha ökad risk för karies, parodontit och tidig tanderuption. / Obesity is a growing, global health problem. Last year (2010) there were more than 43 million overweight children (under the age of five) in the world. The aim of this study was to determine if oral health is affected in overweight children. The authors chose to study publications regarding oral health in overweight children between the ages of 2-19 years. The material was collected from the medical databases PubMed and Science Direct. These results are based on seventeen scientific medical reports. Several studies show that overweight children have more decayed teeth and a greater risk for developing caries than children with normal weight. A small number of studies found a correlation between fewer decayed teeth and overweight children compared to children with normal weight. Another result showed an association between obesity in children that can lead to early tooth eruption and a greater risk for developing periodontitis after the age of 16. More research is required to determine associations between obesity in children and its connections to oral health conditions. It is important for dentists and dental hygienists to be alert to child patients with obesity, as they might have an increased risk for caries, periodontitis and early tooth eruption.