Umeå University's logo

Background: Lifestyle- and sucrose-dependent polymicrobial ecological shifts are a primary cause of caries in populations with high caries prevalence. In populations with low prevalence, PRH1, PRH2 susceptibility and resistance phenotypes may interact with the Streptococcus mutans adhesin cariogenicity phenotype to affect caries progression, but studies are lacking on how these factors affect the microbial profile of caries.

Methods: We analysed how the residency and infection profiles of S. mutans adhesin (SpaP A/B/C and Cnm/Cbm) phenotypes and commensal streptococci and lactobacilli influenced caries progression in a prospective case–referent sample of 452 Swedish adolescents with high (P4a), moderate (P6), and low (P1) caries PRH1, PRH2 phenotypes. Isolates of S. mutans from participants were analysed for adhesin expression and glycosylation and in vitro and in situ mechanisms related to caries activity.

Findings: Among adolescents with the resistant (P1) phenotype, infection with S. mutans high-virulence phenotypes was required for caries progression. In contrast, with highly (P4a) or moderately (P6) susceptible phenotypes, caries developed from a broader polymicrobial flora that included moderately cariogenic oral commensal streptococci and lactobacilli and S. mutans phenotypes. High virulence involved unstable residency and fluctuating SpaP ABC, B-1, or Cnm expression/glycosylation phenotypes, whereas low/moderate virulence involved SpaP A phenotypes with stable residency. Adhesin phenotypes did not display changes in individual host residency but were paired within individuals and geographic regions.

Interpretation: These results suggest that receptor PRH1, PRH2 susceptibility and resistance and S. mutans adhesin virulence phenotypes specify different microbial profiles in caries. Funding: Swedish Research Council and funding bodies listed in the acknowledgement section.

Objectives: The aim was to study self-image and the level of psychological symptoms in patients with symptoms attributed to their dental restorative materials.

Materials and methods: A questionnaire containing questions regarding dental and medical history was answered by 257 participants, one group with local oral symptoms only (LSO), and one group with multi-symptoms (M-S). A reference group was randomly selected from a research database at the Department of Psychology, Umeå University, Sweden. The self-image was assessed using the Structural Analysis of Social Behavior (SASB). Psychological symptoms such as somatization, depression, and anxiety were assessed using the Symptom Check List 90 (SCL-90) and the Global Severity Index (GSI) was used to determine the level of psychological symptoms.

Results: SASB showed that the M-S group and the LSO-group scored significantly higher on the Bspontaneous^ and Bpositive self-image^ than the reference group. In the SCL-90, the M-S group scored significantly higher than the LSO-group and the references on the somatization subscales. On depression, anxiety, and the GSI scale, the M-S group scored significantly higher than the reference group.

Conclusions: The two subgroups scored significantly higher on the SASB Spontaneous and Positive clusters which indicates that these patients have an excessively positive self-image, are very spontaneous and have an overconfidence in themselves compared to the reference group. In the M-S group there was a clear tendency to somatization, depression, and anxiety and they were more psychologically stressed than the reference group.

Clinical relevance: Among the patients with illness attributed to their dental materials, the M-S-patients had a significantly higher level of general psychological distress and somatization than the control group which may lead to mental stress.

Dental caries is a chronic infectious disease that affects billions of people with large individual differences in activity. We investigated whether PRH1 and PRH2 polymorphisms in saliva acidic proline-rich protein (PRP) receptors for indigenous bacteria match and predict individual differences in the development of caries. PRH1 and PRH2 variation and adhesion of indigenous and cariogenic (Streptococcus mutans) model bacteria were measured in 452 12-year-old Swedish children along with traditional risk factors and related to caries at baseline and after 5-years. The children grouped into low-to-moderate and high susceptibility phenotypes for caries based on allelic PRH1, PRH2 variation. The low-to-moderate susceptibility children (P1 and P4a-) experienced caries from eating sugar or bad oral hygiene or infection by S. mutans. The high susceptibility P4a (Db, PIF, PRP12) children had more caries despite receiving extra prevention and irrespective of eating sugar or bad oral hygiene or S. mutans-infection. They instead developed 3.9-fold more caries than P1 children from plaque accumulation in general when treated with orthodontic multibrackets; and had basic PRP polymorphisms and low DMBT1-mediated S. mutans adhesion as additional susceptibility traits. The present findings thus suggest genetic autoimmune-like (P4a) and traditional life style (P1) caries, providing a rationale for individualized oral care.

Dental caries, which affects billions of people, is a chronic infectious disease that involves Streptococcus mutans, which is nevertheless a poor predictor of individual caries development. We therefore investigated if adhesin types of S.mutans with sucrose-independent adhesion to host DMBT1 (i.e. SpaP A, B or C) and collagen (i.e. Cnm, Cbm) match and predict individual differences in caries development. The adhesin types were measured in whole saliva by qPCR in 452 12-year-old Swedish children and related to caries at baseline and prospectively at a 5-year follow-up. Strains isolated from the children were explored for genetic and phenotypic properties. The presence of SpaP B and Cnm subtypes coincided with increased 5-year caries increment, and their binding to DMBT1 and saliva correlated with individual caries scores. The SpaP B subtypes are enriched in amino acid substitutions that coincided with caries and binding and specify biotypes of S. mutans with increased acid tolerance. The findings reveal adhesin subtypes of S. mutans that match and predict individual differences in caries development and provide a rationale for individualized oral care.

Anxiety for adverse health effects attributed to dental restorative materials especially dentalamalgam, have been discussed extensively off and on the last 30 years. The possible health effect ofamalgam and health effect of replacements of amalgam, have been extensively studied but theresults are inconclusive and the etiology of the reactions are not entirely elucidated. Furthermore,the question of psychological influence on symptoms attributed to dental restorative materials hasbeen raised and need further examination.

The aims of this thesis were to describe the change in health over time for patient with symptomsattributed to their dental materials and to determine whether replacement of their dentalrestorative materials had any impact on their perceived health. Furthermore, to determine anddescribe the personality, self-image, level of psychological symptoms and stress among thesepatients and compare the results with those of healthy controls. Finally, to evaluate regression ofLichenoid Contact Reactions and Oral lichen Planus after replacement of the dental materials.

A questionnaire was mailed to 614 patients that had been referred to the School of Dentistry, Umeå,Sweden with symptoms attributed to dental materials. Among these patients a subgroup with orallichen also underwent a clinical examination at follow-up.

The result showed that patients with complex symptoms had a more unfavorable long-termprognosis concerning persistent complaints than those with local symptoms only. The oralsymptoms had decreased between baseline and follow-up and the general symptoms had increased.The increase in general symptoms was contradictory since many patients experienced healthimprovement after removal of their dental restorative materials. Concerning personality thepatients was characterized mainly by high persistence and by high fatigability and asthenia as wellas psychosocially learned high self-acceptance. Regarding self-image, both patients with LocalSymptoms Only and patients with Multi Symptoms, scored significantly higher on "spontaneous"and "positive self-image" than the reference group. The Multi symptoms group scored significantlyhigher on psychological symptoms compared to the reference group. However, the Local symptomsgroup did not differ from the references. The remission of oral lesions was after an exchange ofdental materials was seen to a greater extent in patients with Lichenoid Contact Reaction than inpatients with Oral Lichen Planus. Regarding psychological parameters, there were no significantdifferences between the groups.

In conclusion symptoms related to dental restorative materials seem to be multi-factorial wheredental, medical, social, and psychological factors may be involved. Patient with complex symptomshave a more unfavorable prognosis than patient with local symptoms only. Patient with symptomsself-related to their dental materials may feel improvement in general health after an exchange ofdental materials. The group of patients seems to represent personalities that could be vulnerable inthe demanding modern society, and the various mental and somatic symptoms can be interpretedas attributed to dental fillings. Patients with Local Symptoms or Multi Symptoms are equalconcerning self-image, they are impulsive with an elevated positive self-image, that can result indifficulties in setting limits. Thus in combination with high demands may result in mental stress.The Multi Symptoms group was more psychologically stressed than the group with Local SymptomsOnly and the references. Therefore, before an exchange of dental materials is commenced inpatients with oral lichenoid lesions, a correct diagnosis is needed.

The aim of this study was to explore the experiences of illness and the encounters with health care professionals among women who attributed their symptoms and illness to either dental restorative materials and/or electromagnetic fields, despite the fact that research on health effects from dental fillings or electricity has failed to substantiate the reported symptoms. Thirteen women (aged 37-63 years) were invited to the study and a qualitative approach was chosen as the study design, and data were collected using semi-structured interviews. The analysis was conducted with a constant comparative method, according to Grounded Theory. The analysis of the results can be described with the core category, "Struggle to obtain redress," the two categories, "Stricken with illness" and "A blot in the protocol," and five subcategories. The core category represents the women's fight for approval and arose in the conflict between their experience of developing a severe illness and the doctors' or dentists' rejection of the symptoms as a disease, which made the women feel like malingerers. The informants experienced better support and confirmation from alternative medicine practitioners. However, sick-leave certificates from alternative medicine practitioners were not approved and this led to a continuous cycle of visits in the health care system. To avoid conflicting encounters, it is important for caregivers to listen to the patient's explanatory models and experience of illness, even if a medical answer cannot be given.

The aim of the study was to determine the prognosis and to evaluate the regression of lichenoid contact reactions (LCR) and oral lichen planus (OLP) after replacement of dental restorative materials suspected as causing the lesions. Forty-four referred patients with oral lesions participated in a follow-up study that was initiated an average of 6years after the first examination at the Department of Odontology, i.e. the baseline examination. The patients underwent odontological clinical examination and answered a questionnaire with questions regarding dental health, medical and psychological health, and treatments undertaken from baseline to follow-up. After exchange of dental materials, regression of oral lesions was significantly higher among patients with LCR than with OLP. As no cases with OLP regressed after an exchange of materials, a proper diagnosis has to be made to avoid unnecessary exchanges of intact restorations on patients with OLP.

Abstract –  Objectives:  In Sweden, many patients with symptoms allegedly caused by their dental materials have exchanged their restorations, but the effects of the exchange have been insufficiently investigated. Therefore, the aim of the study was to describe the change in health over time for these patients and the hypothesis was that the patients could be divided based on their symptoms and that the ability to recover differs between these groups. Furthermore, we also examined if other factors such as replacement of dental restorative materials and follow-up time had any impact on the perceived health status.

Methods:  A questionnaire was sent to 614 patients who had been referred to the School of Dentistry, Umeå, Sweden, with symptoms allegedly caused by dental restorative materials. The response rate was 55%.

Results:  The risk of having any further complaints was higher for patients with complex symptoms (P = 0.03) and these patients had exchanged their restorations to a significantly larger extent than the others (P = 0.03). The remaining complaints was more frequent among men (P = 0.02). Exchange of dental restorative materials had no significant impact on the ability to recover completely. However, the patients who had exchanged their restorations completely perceived a significantly larger alleviation of their symptoms than the others (P < 0.01), although the frequency of most of the symptoms had increased.

Conclusions:  Patients with complex symptoms had a more unfavorable long-term prognosis concerning persistent complaints than those with localized symptoms only. Furthermore, the results indicate that the patients might experience health improvements after removal of their dental restorative materials. The reason for this improvement, however, is unclear. Further analyses regarding other possible explanations than the ‘odontological/medical’ are needed.

The aim of the present study was to investigate the psychobiological personality dimensions in two subgroups of patients with environmental illness (EI). Fifty-nine patients, 34 women and 25 men (aged 32-69 years), were referred for symptoms allegedly caused by abnormal sensitivity to either dental fillings (DF; n=26) or electromagnetic fields (EMF; n=33). For the evaluation of personality, the Swedish 238-item version of the Temperament and Character Inventory (TCI) was used. Compared with a control group, the EMF group scored higher on the temperament dimension Persistence. The DF group scored higher on the TCI subscales Harm Avoidance (fatigability and asthenia) and Self-Directedness (self-acceptance). Women scored higher than men did on the Novelty Seeking and Reward Dependence (RD) dimensions in the DF group and on RD in the control group, indicating an inherited gender difference. No differences were found between men and women in the EMF group. Our results indicate that the high level of persistence found in the EMF group and the high level of fatigability and asthenia in combination with high self-acceptance found in the DF group represent vulnerable personalities. No significant differences were found between the two patient groups, indicating that these groups are quite similar regarding personality. This vulnerability can be expressed as various mental and somatic symptoms, which can be interpreted as El symptoms by the affected individual.