Some young adults can maintain good oral health despite socioeconomic challenges.

The association between dental caries experience and socioeconomic status, as reflected in income and educational level, is well known. However, some individuals maintain good health despite socioeconomic disadvantage. The aim of this qualitative study was to explore salutogenic (health-promoting) factors among healthy caries-free young adults of low socioeconomic status. Seventeen participants (11 women), 19-23 years of age, who were caries-free and of low socioeconomic status were interviewed in-depth. The interviews were transcribed verbatim and analysed using qualitative content analysis with an inductive approach. The theme revealed was 'Building trust and shifting responsibility from parent to child throughout children's development lays the salutogenic foundation for oral health', comprising three categories: (i) a basis for health; (ii) creating one's own path by testing wings; and (iii) developing resources for health. A feeling of trust was expressed, participants were confident in the unconditional support of their caregivers, and caregivers were trusting participants to be able to take control over their own oral health. Health-promotive factors were established not only by instilling healthy habits during childhood, but also by parental guidance through adolescence, enabling young adults to develop resources and assets to take control over their own health independently.

[Dental caries - the most common noncommunicable disease and its impact on general health and disease]. / Karies ­ världens vanligaste icke smittsamma sjukdom.

More than 2.8 billion individuals worldwide suffer from untreated caries. Over ninety-five percent of all 50-year-olds in Sweden have caries experience. Caries is the most common cause of dental restorations and tooth loss. Tooth loss is associated with cardiovascular diseases, dementia, and death. Periapical tooth infections caused by caries can spread and cause severe infection, however rarely with lethal outcome. Sugars are a common risk factor for caries and other noncommunicable diseases such as cardiovascular diseases, diabetes, and obesity.  Caries is a consequence of sugar-provoked acid production and dysbiosis in the tooth biofilm (dental plaque). There are several conditions which may increase the risk for dental caries, such as different medical conditions and medications which may cause dry mouth. Treatment costs for caries are high.

Streptococcus Species Abundance in the Gut Is Linked to Subclinical Coronary Atherosclerosis in 8973 Participants From the SCAPIS Cohort.

BACKGROUND: Gut microbiota have been implicated in atherosclerotic disease, but their relation with subclinical coronary atherosclerosis is unclear. This study aimed to identify associations between the gut microbiome and computed tomography-based measures of coronary atherosclerosis and to explore relevant clinical correlates. METHODS: We conducted a cross-sectional study of 8973 participants (50 to 65 years of age) without overt atherosclerotic disease from the population-based SCAPIS (Swedish Cardiopulmonary Bioimage Study). Coronary atherosclerosis was measured using coronary artery calcium score and coronary computed tomography angiography. Gut microbiota species abundance and functional potential were assessed with shotgun metagenomics sequencing of fecal samples, and associations with coronary atherosclerosis were evaluated with multivariable regression models adjusted for cardiovascular risk factors. Associated species were evaluated for association with inflammatory markers, metabolites, and corresponding species in saliva. RESULTS: The mean age of the study sample was 57.4 years, and 53.7% were female. Coronary artery calcification was detected in 40.3%, and 5.4% had at least 1 stenosis with >50% occlusion. Sixty-four species were associated with coronary artery calcium score independent of cardiovascular risk factors, with the strongest associations observed for Streptococcus anginosus and Streptococcus oralis subsp oralis (P<1×10-5). Associations were largely similar across coronary computed tomography angiography-based measurements. Out of the 64 species, 19 species, including streptococci and other species commonly found in the oral cavity, were associated with high-sensitivity C-reactive protein plasma concentrations, and 16 with neutrophil counts. Gut microbial species that are commonly found in the oral cavity were negatively associated with plasma indole propionate and positively associated with plasma secondary bile acids and imidazole propionate. Five species, including 3 streptococci, correlated with the same species in saliva and were associated with worse dental health in the Malmö Offspring Dental Study. Microbial functional potential of dissimilatory nitrate reduction, anaerobic fatty acid ß-oxidation, and amino acid degradation were associated with coronary artery calcium score. CONCLUSIONS: This study provides evidence of an association of a gut microbiota composition characterized by increased abundance of Streptococcus spp and other species commonly found in the oral cavity with coronary atherosclerosis and systemic inflammation markers. Further longitudinal and experimental studies are warranted to explore the potential implications of a bacterial component in atherogenesis.

Dental professionals' perception of their role in the practice of oral health promotion: a qualitative interview study.

OBJECTIVE: To explore dental professionals' perceptions of their role in the practice of oral health promotion. MATERIAL AND METHOD: In-depth interviews were conducted with three dentists, one specialist dentist and seven dental hygienists. All were employed in the public dental service in Kalmar County, Sweden and had at least 2 years' work experience. The interview questions addressed the experience and views of dental professionals with reference to their role in the practice of health promotion. The interview data were subjected to qualitative content analysis. RESULTS: Analysis revealed two themes which capture the essence of the dental professionals' perception of their role in the practice of oral health promotion. One theme, having person-focused approach, comprised four categories: 'considering the patient's life situation', 'establishing a trusting relationship with patients', 'strengthening patients' commitment to oral health' and 'health education'. The other theme, perceiving social responsibility for oral health, comprised three categories: 'dissemination of oral health knowledge', 'interprofessional collaboration' and 'equality in oral health care'. CONCLUSION: Dental professionals perceived promotion of oral health to be an important aspect of their professional role. They aspired to patient participation in the decision-making process and educational activities, as well as practising and evaluating skills development. Although the dental professionals perceived that they undertook health promotion activities, they did not clearly distinguish between oral health promotion and disease prevention. There was intra- and inter-professional agreement among the dentists and dental hygienists with respect to expected outcomes for health promotion activities.

Common resilience factors among healthy individuals exposed to chronic adversity: a systematic review.

OBJECTIVE: To identify common resilience factors against non-communicable diseases (dental caries, diabetes type II, obesity and cardiovascular disease) among healthy individuals exposed to chronic adversity. MATERIALS AND METHODS: The databases MEDLINE (via PubMed), Scopus and CINAHL were searched. Observational studies in English assessing resilience factors among populations living in chronic adversity were included. Intervention studies, systematic reviews, non-original articles and qualitative studies were excluded. There were no restrictions regarding publication year or age. No meta-analysis could be done. Quality assessments were made with the Newcastle-Ottawa scale (NOS). RESULTS: A final total of 41 studies were included in this systematic review. The investigated health resilience factors were divided into the following domains: environmental (community and family) and individual (behavioural and psychosocial). A narrative synthesis of the results was made according to the domains. CONCLUSIONS: Individual psychosocial, family and environmental factors play a role as health resilience factors in populations living in chronic adversity. However, the inconclusive results suggest that these factors do not act in isolation but interplay in a complex manner and that their interaction may vary during the life course, in different contexts, and over time.

Effect of a single application of silver diamine fluoride on root caries after 12 months in institutionalised older adults-A randomised clinical trial.

OBJECTIVE: Silver diamine fluoride (SDF) has been shown to be highly effective against caries, in particular for arresting root surface caries and for dentine caries in primary teeth. SDF may complement fluoride varnish routines for treatment of root caries in nursing home residents. The aim of this randomised, single-blinded, placebo-controlled trial was to evaluate the additive effect of a single annual application of SDF for prevention and treatment of incipient root caries in older adult nursing home residents. METHOD: Four hundred older adult nursing home residents (≥70 years old) with at least one exposed root surface (on teeth 15, 14, 13, 23, 24, or 25) were identified during routine dental examination visits in the domiciliary dental care setting. Eligible patients, who were able to understand the implication of consenting to the study, were invited to participate. Their cleaned root surfaces were randomly allocated to treatment with SDF (Advantage Arrest Silver Diamine Fluoride 38%, Advantage Arrest, LLC, Redmond, OR 97756, USA, Lot 16 152) or with placebo (tap water), each for 1 minute. RESULTS: Of the 400 eligible individuals, 42 declined to participate and two forms were destroyed. The remaining 356 participants (89.0%; mean age 87.7 years) were randomly allocated, with 174 going to the SDF group and 182 to the placebo group. At 1 year, 273 participants (76.7%) were available for assessment: 135 in the SDF group and 138 in the placebo group. By that time, 109 individuals (39.9%) demonstrated root caries progression or regression. Among those 118 (16.7%) of the 708 included root surfaces had developed caries There were no statistically significant differences in the primary outcome related to treatment with SDF or placebo, at either patient or root surface level. CONCLUSION: Based on the finding of this clinical trial, it is concluded that a single SDF application to complement a risk-based preventive programme including fluoride varnish applications did not have a statistically significant additional preventive effect on root caries development in a group of older adult nursing home residents with limited caries activity and cognitive capacity to cooperate in oral care activities.

Exploring salutogenic factors supporting oral health in the elderly.

AIM: To explore associations between salutogenic factors and selected clinical outcome variables of oral health in the elderly, combining Antonovsky's salutogenic theory and the Lalonde Health Field concept. METHODS: The subjects comprised 146 individuals, aged 60 years and older, who had participated in a population-based epidemiological study in Sweden, 2011-2012, using questionnaire and oral examination data. A cross-sectional analysis used the selected outcome variables, such as number of remaining teeth, DMFT-index and risk assessment, and salutogenic factors from the questionnaire, clustered into domains and health fields, as artifactual-material, cognitive-emotional and valuative-attitudinal. This selection was based on findings from our previous analysis using a framework cross-tabulating two health models. The purpose was to facilitate analysis of associations not previously addressed in the literature on oral health. Bivariate and Multiple Linear Regression analyses were used. RESULTS: Numerous salutogenic factors were identified. Significant associations between outcome variables and salutogenic factors previously unreported could be added. Regression analysis identified three contributing independent factors for 'low DMFT'. CONCLUSIONS: This study supports the usefulness of a salutogenic approach for analysing oral health outcomes, identifying university education, the importance of dental health organization recall system and close social network, as important salutogenic factors. The large number of salutogenic factors found supporting oral health among the elderly indicates the complexity of salutogenesis and the need for robust analysing tools. Combining two current health models was considered useful for exploring these covariations. These findings have implications for future investigations, identifying important research questions to be explored in qualitative analyses.

Self-perceived oral health-related salutogenic factors in orally healthy older Swedes. A qualitative interview study.

OBJECTIVE: This study aimed to explore oral health-related salutogenic factors in orally healthy older Swedish people, applying the three components of Antonovsky's Sense of Coherence (SOC) concept: comprehensibility, manageability and meaningfulness. MATERIAL AND METHOD: Interviews were conducted with 12 orally healthy patients, aged 75 years and older, enrolled at public dental clinics. The interviews were subjected to qualitative content analysis, applying the SOC concept as the theoretical framework. RESULTS: Three themes were formulated under the predefined SOC components, describing the central meaning of the informants' perception of factors favourable to their good oral health. The theme 'comprehension of cause and effect' consisted of three categories, for example importance of oral hygiene, and reflected the component comprehensibility. The theme 'living in confidence and trust in supporting society' consisted of five categories, for example self-esteem, and reflected the component manageability. The theme 'good oral health as a basis for satisfaction and social confidence' consisted of two categories, for example social norms, and reflected the component meaningfulness. CONCLUSION: This study discloses how orally healthy elderly Swedish people perceive the lifelong impact of salutogenic factors in response to lifelong stressors on their oral health and highlights the important roles of their internal resources, dental professionals, family and society in supporting and reinforcing lifelong oral health.

Risk Factors for Dental Erosion After Bariatric Surgery: A Patient Survey.

INTRODUCTION: Treatment of obesity by bariatric surgery has increased in recent years. Reported side effects that may predispose to dental erosion include reflux, vomiting, and an increased frequency of intake of food and drink. OBJECTIVE: The aim was to investigate long-term dietary behaviour and experiences related to symptoms of dental erosion at least 5 years after bariatric surgery. METHODS: An online questionnaire study was conducted amongst 250 patients who had undergone bariatric surgery at King Saud Medical City in Saudi Arabia 5 years ago or more. It comprised 36 questions on demographic data, dietary habits, general health, dental health, and oral symptoms. The data were analysed using Chi-square and sign tests (significance level P < .05). RESULTS: A significant increase in acidic reflux and vomiting was found after bariatric surgery and appeared to increase with time after surgery. Also, a significant association between presence of acidic reflux and symptoms of dental erosion was found. However, 68.5% reported improved overall well-being after surgery. The response rate was 21.6% (most were female, aged 30-59 years). Respondents were generally not advised to visit a dentist in connection with bariatric surgery. CONCLUSIONS: This long-term cross-sectional study suggests a time-dependent, increasing occurrence of vomiting and acidic reflux after bariatric surgery. Vomiting and reflux became even more common after 5 to 10 years. A significant relationship emerged between a high frequency of acidic reflux and a high frequency of oral symptoms related to dental erosion. Daily occurrence of general symptoms related to dumping syndrome were reported by the majority. However, in a 5- to 10-year perspective, general symptoms related to dumping syndrome and symptoms from dental erosion did not seem to detract from the respondents' overall satisfaction with daily living. Oral health problems might be reduced if patients who had bariatric surgery were referred to a dentist for prevention and monitoring.

Salutogenic factors for oral health among older people: an integrative review connecting the theoretical frameworks of Antonovsky and Lalonde.

OBJECTIVE: The aim of this integrative review was to describe salutogenic factors associated with oral health outcomes in older people, from the theoretical perspectives of Antonovsky and Lalonde. MATERIAL AND METHODS: This study was based on a primary selection of 10,016 articles. To organize reported salutogenic factors, the Lalonde health field concept and Antonovsky's salutogenic theory were cross tabulated. RESULTS: The final analysis was based on 58 studies. The following oral health outcome variables were reported: remaining teeth, caries, periodontal disease, oral function and oral health related quality of life (OHRQoL). We could identify 77 salutogenic factors for oral health and OHRQoL. Salutogenic factors were identified primarily within the fields of Human Biology (such as 'higher saliva flow', 'BMI < 30 kg/m2' and 'higher cognitive ability at age 11'), Lifestyle (such as 'higher education level', 'social network diversity' and 'optimal oral health behaviour') and Environment (such as 'lower income inequality', 'public water fluoridation' and 'higher neighbourhood education level'). In the age group 60 years and over, there was a lack of studies with specific reference to salutogenic factors. CONCLUSIONS: The results provide an overview of salutogenic factors for oral health from two theoretical perspectives. The method allowed concomitant disclosure of both theoretical perspectives and examination of their congruence. Further hypothesis-driven research is needed to understand how elderly people can best maintain good oral health.

Salivary fluoride concentration and retention after rinsing with 0.05 and 0.2% sodium fluoride (NaF) compared with a new high F rinse containing 0.32% NaF.

OBJECTIVE: To compare salivary fluoride (F) concentration and F retention after rinsing with a new 0.32% sodium fluoride (NaF) rinse and conventional 0.05 and 0.2% NaF rinses. METHODS: Seventeen subjects (aged 22-26 years), with normal salivary secretion rates, participated in a double blind, cross-over study. In three separate sessions with a minimum washout period of 48 h, they rinsed for 1 min with 10 ml of 0.05, 0.2 or 0.32% NaF mouthrinse. Unstimulated whole saliva was collected before (baseline: 0 min) and after 1, 3, 5, 10, 20, 30, 45 and 60 min. The F concentration was plotted against time, and the area under the curve (AUC) calculated. Salivary F concentration and F retention for the three mouthrinses were compared by a randomized block test, followed by Tukey's test and a paired 2-tailed test. RESULTS: There was a clear dose-response for AUC 3-60 min; 0.32% > 0.2% > 0.05% (p < .05). The mean F retention was 0.25 mg for 0.05% NaF, 0.86 mg F for 0.2% Na and 1.31 mg F for 0.32% NaF, (p < .05). CONCLUSIONS: The higher salivary F concentration over time and the higher F retention after rinsing with an 0.32% NaF solution suggests a potential application in prevention of caries and dental erosion.

Why Do Adolescents Use Fluoride Toothpaste? A Qualitative Interview Investigation.

PURPOSE: Fluoride toothpastes are effective in caries prevention. In legislation, regular fluoride toothpaste is a cosmetic product; adolescents use it for aesthetic purposes. In dentistry, fluoride toothpaste is considered a caries preventive drug recommended to patients for that reason. Knowledge is lacking concerning what motivates adolescents to use fluoride toothpaste. Dental professionals need to understand how to motivate a risk-group for caries development to use fluoride toothpaste frequently in order to effectively motivate patients to prevent tooth decay. The purpose of this study was to investigate what motivates adolescents to use fluoride toothpaste. MATERIALS AND METHODS: The study was conducted at a high school in southern Sweden. The final sample consisted of 16 adolescents age 16 to 19. This study employed a qualitative design using semi-structured interviews. The data were analysed using manifest content analysis with an occasional inductive approach. RESULTS: Reasons for why adolescents use fluoride toothpaste were found in four different categories: oral health, economy, upbringing and habit, social influences. CONCLUSION: There are reasons to believe that dental professionals might have missed important arguments for why adolescents use fluoride toothpaste. The participants mentioned oral health and aesthetics as important reasons for using fluoride toothpaste, as well as other more surprising factors such as financial reasons and social environment. There are thus more arguments for using fluoride toothpaste that adolescents value than the ones we believe dental professionals use.

Odontoblast-like MDPC-23 cells produce pro-inflammatory IL-6 in response to lipoteichoic acid and express the antimicrobial peptide CRAMP.

Objective: Odontoblasts are thought to be involved in innate immunity but their precise role in this process is not fully understood. Here, we assess effects of lipopolysaccharide (LPS) and lipoteichoic acid (LTA), produced by Gram-negative and Gram-positive bacteria, respectively, on matrix metalloproteinase-8 (MMP-8), interleukin-6 (IL-6) and cathelin-related antimicrobial peptide (CRAMP) expression in odontoblast-like MDPC-23 cells.Material and methods: Gene activity and protein production was determined by quantitative real-time RT-PCR and ELISA, respectively. Cellular expression of CRAMP was determined by immunocytochemistry.Results: Stimulation with LTA (5 and 25 µg/ml) but not LPS (1 and 5 µg/ml) for 24 h enhanced IL-6 mRNA expression. The LTA-induced up-regulation of IL-6 mRNA levels was associated with increased IL-6 protein levels. Stimulation with either LPS or LTA for 24 h lacked effect on both MMP-8 transcript and protein expression. Immunocytochemistry disclosed that MDPC-23 cells expressed immunoreactivity for CRAMP. MDPC-23 cells showed mRNA expression for CRAMP, but stimulation with either LPS or LTA did not modulate CRAMP transcript expression.Conclusions: We show that MDPC-23 cells possess immune-like cell properties such as LTA-induced IL-6 production and expression of the antimicrobial peptide CRAMP, suggesting that odontoblasts may modulate innate immunity via these mechanisms.

Swedish Quality Registry for Caries and Periodontal Diseases - a framework for quality development in dentistry.

OBJECTIVES: There is a need for monitoring dental health and healthcare, as support for quality development, allocation of resources and long-term planning of dental care. The aim of this paper is to describe the concept and implementation of the Swedish Quality Registry for Caries and Periodontal Diseases (SKaPa). MATERIALS AND METHODS: The SKaPa receives information by automatic transfer of data daily from electronic patient dental records via secure connections from affiliated dental care organisations (DCOs). The registry stores information about DCOs, dental professionals and patients. Information on a patient level includes personal identifier, gender, age, living area, dental status, risk assessments for caries and periodontitis, and dental care provided. In addition, data generated from a global question on patient-perceived oral health are uploaded. In total, more than 400 variables are transferred to the registry and updated daily. RESULTS: In 2018, all of the 21 public DCOs and the largest private DCO in Sweden were affiliated to SKaPa, representing a total of 1,089 public and 234 private dental clinics. The accumulated amount of information on dental healthcare covers 6.9 million individuals out of the total Swedish population of 10 million. SKaPa produces reports on de-identified data, both cross-sectional and longitudinal. CONCLUSION: As a nationwide registry based on automatic retrieval of data directly from patient records, SKaPa offers the basis for a new era of systematic evaluation of oral health and quality of dental care. The registry supports clinical and epidemiological research, data mining and external validation of results from randomised controlled trials.

The host defense peptide LL-37 is detected in human parotid and submandibular/sublingual saliva and expressed in glandular neutrophils.

The human host defense peptide, LL-37, is an important player in the first line of defense against invading microorganisms. LL-37 and its precursor, hCAP18, have been detected in unstimulated whole saliva but no reports showing hCAP18/LL-37 in isolated, parotid, and/or submandibular/sublingual saliva have been presented. Here, we measured the levels of hCAP18/LL-37 in human parotid and submandibular/sublingual saliva and investigated the expression of hCAP18/LL-37 in parotid and submandibular gland tissue. Parotid and submandibular/sublingual saliva was collected from healthy volunteers, and the levels of hCAP18/LL-37 in saliva were analyzed by dot blot, ELISA, and western blotting. Cellular expression of hCAP18/LL-37 in human parotid and submandibular glands was investigated by immunohistochemistry. Immunoreactivity for hCAP18/LL-37 was detected in both parotid and submandibular/sublingual saliva of all individuals. The concentration of hCAP18/LL-37 was similar in parotid and submandibular/sublingual saliva, and was determined by densitometric scanning of each dot and normalization to the total protein concentration of each sample, and by ELISA. Double immunohistochemistry revealed that intravascular neutrophils of both parotid and submandibular glands express hCAP18/LL-37. For the first time, we demonstrate hCAP18/LL-37 in isolated human parotid and submandibular/sublingual saliva and expression of hCAP18/LL-37 in glandular intravascular neutrophils, indicating that neutrophils of the major salivary glands contribute to the LL-37 content of whole saliva.

Comparison of risk assessment based on clinical judgement and Cariogram in addition to patient perceived treatment need.

BACKGROUND: Predicting future risk for oral diseases, treatment need and prognosis are tasks performed daily in clinical practice. A large variety of methods have been reported, ranging from clinical judgement or "gut feeling" or even patient interviewing, to complex assessments of combinations of known risk factors. In clinical practice, there is an ongoing continuous search for less complicated and more valid tools for risk assessment. There is also a lack of knowledge how different common methods relates to one another. The aim of this study was to investigate if caries risk assessment (CRA) based on clinical judgement and the Cariogram model give similar results. In addition, to assess which factors from clinical status and history agree best with the CRA based on clinical judgement and how the patient's own perception of future oral treatment need correspond with the sum of examiners risk score. METHODS: Clinical examinations were performed on randomly selected individuals 20-89 years old living in Skåne, Sweden. In total, 451 individuals were examined, 51 % women. The clinical examination included caries detection, saliva samples and radiographic examination together with history and a questionnaire. The examiners made a risk classification and the authors made a second risk calculation according to the Cariogram. RESULTS: For those assessed as low risk using the Cariogram 69 % also were assessed as low risk based on clinical judgement. For the other risk groups the agreement was lower. Clinical variables that significantly related to CRA based on clinical judgement were DS (decayed surfaces) and combining DS and incipient lesions, DMFT (decayed, missed, filled teeth), plaque amount, history and soft drink intake. Patients' perception of future oral treatment need correlated to some extent with the sum of examiners risk score. CONCLUSIONS: The main finding was that CRA based on clinical judgement and the Cariogram model gave similar results for the groups that were predicted at low level of future disease, but not so well for the other groups. CRA based on clinical judgement agreed best with the number of DS plus incipient lesions.

Lactobacillus reuteri supplements do not affect salivary IgA or cytokine levels in healthy subjects: A randomized, double-blind, placebo-controlled, cross-over trial.

OBJECTIVES: To evaluate the effect of daily ingestion of probiotic lactobacilli on the levels of secretory IgA (sIgA) and selected cytokines in whole saliva of healthy young adults. MATERIALS AND METHODS: The study group consisted of 47 healthy adults (18-32 years) who volunteered for a randomized, double-blind, placebo-controlled, cross-over trial after informed consent. During intervention, the subjects ingested two lozenges per day containing two strains of the probiotic bacterium Lactobacillus reuteri (DSM 17938 and ATCC PTA 5289) or placebo lozenges. The intervention and wash-out periods were 3 weeks. Saliva samples were collected at baseline, immediately after each intervention period and 3 weeks post-intervention. ELISA was used to measure sIgA and luminex technology was used to measure the interleukins (IL)-1ß, IL-6, IL-8 and IL-10. For statistical analyses a mixed ANOVA model was employed to calculate changes in the salivary outcome variables. RESULTS: Forty-one subjects completed the study and reported a good compliance. No significant differences in the concentrations of salivary sIgA or cytokines were recorded between the L. reuteri and placebo interventions or between baseline and 3 weeks post-intervention levels. No side- or adverse effects were reported. CONCLUSIONS: Supplementation with two strains of the probiotic L. reuteri did not affect sIgA or cytokine levels in whole saliva in healthy young adults. The results thereby indicate that daily oral supplementation with L. reuteri do not seem to modulate the salivary oral immune response in healthy young subjects (ClinicalTrials.gov NCT02017886).

Collagen degradation and preservation of MMP-8 activity in human dentine matrix after demineralization.

OBJECTIVE: Dental caries is a process driven by acids produced by oral microorganisms followed by degradation of the dentine collagen matrix by proteolytic enzymes. Matrix metalloproteinases (MMPs) have been suggested to contribute to caries by degrading collagen. The aim of this study was to develop a method for generating demineralized dentine matrix substrate (DDM) maintaining MMP-8 bioactivity and no interference with later assays. Such a substrate would allow study of the effects of various treatments on MMP-8 activity and collagen degradation in demineralized dentine. DESIGN: Human dentine was powderized in a tissue grinder and frozen (-80°C). The powder was demineralized in dialysis tubes, using EDTA or acetic acid. The demineralized dentine matrix (DDM) was harvested and analyzed for collagen content using SDS-PAGE. The DDM was subsequently suspended in PBS or TESCA buffer. Protein, MMP-8 (ELISA) and collagen (HYP) was analyzed directly or after 1 wk. RESULTS: EDTA or acid demineralization of dentine using dialysis yielded a substrate rich in collagen coupled with preserved MMP-8 activity. Collagen degraded in room temperature, assessed by higher HYP amounts in the soluble fraction of DDM after one wk, indicating that the methods used preserved active DDM-components after the demineralization process. CONCLUSIONS: The presented demineralization methods both provided insoluble DDM substrates suitable for further intervention studies. However, it was found that the substrates differed depending on the demineralization method and buffers used. This needs further study to find an optimal technique for generating DDM with retained proteins as well as enzymatic bioactivity.

Caries correlates strongly to salivary levels of matrix metalloproteinase-8.

The caries process in dentin involves the degradation of both mineral and organic matrix. The demineralization has been demonstrated to be caused by bacterial acids. However, the collagen degradation is considered to be initiated by endogenous proteolytic enzymes, mainly collagenolytic matrix metalloproteinases (MMPs). This paper aims to relate salivary MMP-8 (or salivary collagenase-2) and tissue inhibitor of MMP (TIMP-1) levels to manifest caries in a large number of subjects. A random sample of 451 adults (aged 18-87 years) living in the south of Sweden was included in this study. Standard clinical examinations were performed, and stimulated saliva was collected and analyzed for concentrations of MMP-8, TIMP-1 and total protein, using an immunofluorometric assay, an enzyme-linked immunosorbent assay and the Bradford assay, respectively. Salivary numbers of mutans streptococci and lactobacilli were determined using a chair-side kit. Subjects with manifest caries lesions presented with elevated levels of MMP-8 (p < 0.001) as well as total protein, MMP-8/TIMP-1 ratio, bleeding on probing and plaque index (p = 0.05) compared with subjects without manifest caries. Multiple linear regression analysis with caries as the dependent variable revealed MMP-8 as the only significant explanatory variable (p < 0.001). TIMP-1 was not significant in any case. Using MMP-8 as the dependent variable revealed total protein concentration, caries lesions (p ≤ 0.001) and salivary secretion rate (p = 0.05) as explanatory variables. In conclusion, our data reveal that subjects with manifest caries lesions have elevated levels of salivary MMP-8 relative to subjects with no caries lesions.