Human PRH1, PRH2 susceptibility and resistance and Streptococcus mutans virulence phenotypes specify different microbial profiles in caries.

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.

Psychological symptoms and self-image of patients with complaints attributed to dental restorative materials.

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 "spontaneous" and "positive 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.

Genetic- and Lifestyle-dependent Dental Caries Defined by the Acidic Proline-rich Protein Genes PRH1 and PRH2.

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.

Streptococcus Mutans Adhesin Biotypes that Match and Predict Individual Caries Development.

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.

"Struggle to obtain redress": Women's experiences of living with symptoms attributed to dental restorative materials and/or electromagnetic fields.

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.

Replacement of restorations in subjects with symptoms associated with dental restorations; a follow-up study.

The aim of this follow-up study was to assess the long-term development of symptoms and their social consequences among patients referred for diagnosis and treatment of symptoms believed to be related to dental-restorative materials. A questionnaire was sent to 614 such patients containing questions on civil status, present health, changes between baseline and follow-up, current employment situation, and consequences of the problems. The results showed that patients with complex symptoms at baseline had a worse prognosis (i.e. more symptoms remaining) at follow-up than patients with local symptoms only. Replacement of dental materials seemed to have the largest impact on the alleviation of the symptoms reported. Those with remaining complex symptoms had more often stopped working or had decreased their work hours because of their symptoms. Only one-sixth of the patients were symptom-free at the follow-up. Our results indicate a relationship between patients with complex symptoms and social consequences in daily life. Therefore, social factors must be taken into consideration when examining the patients. Dental, medical, and social factors have to be considered simultaneously when examining a patient with symptoms that they relate to dental materials, in order to recommend appropriate care-management programs for this group of patients.

Psychobiological personality dimensions in two environmental-illness patient groups.

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 EI symptoms by the affected individual.