Human gingival epithelial cells stimulate proliferation, migration, and tube formation of lymphatic endothelial cells in vitro

Objective The aim of this study was to investigate the response of gingival epithelial cells to microbial and inflammatory signals. Background The gingival epithelial barrier provides the first line of defense and supports tissue homeostasis by maintaining the cross-talk between gingival epithelium, oral microbiota, and immune cells. Lymphatic vessels are essential to sustaining this homeostasis. The gingival epithelial cells have been shown to produce prolymphangiogenic factors during physiologic conditions, but their role in response to microbial and inflammatory signals is unknown. Methods Immortalized human gingival epithelial cells (HGEC) and human dermal lymphatic microvascular endothelial cells (LEC) were cultured. HGEC were exposed to Porphyromonas gingivalis derived-LPS, human IL-1 beta/IL-1F2 protein, or recombinant human IL-6/IL-6R. Levels of vascular growth factors (VEGF-A, VEGF-C, and VEGF-D) in cell supernatants were determined by ELISA. LEC were grown to confluence, and a scratch was induced in the monolayer. Uncovered area was measured up to 48 h after exposure to conditioned medium (CM) from HGEC. Tube formation assays were performed with LEC cocultured with labelled HGEC or exposed to CM. Results VEGF-A, VEGF-C, and low levels of VEGF-D were constitutively expressed by HGEC. The expression of VEGF-C and VEGF-D, but not VEGF-A, was upregulated in response to proinflammatory mediators. VEGF-C was upregulated in response to P. gingivalis LPS, but not to Escherichia coli LPS. A scratch migration assay showed that LEC migration was significantly increased by CM from HGEC. Both the CM and coculture with HGEC induced significant tube formation of LEC. Conclusions HGEC can regulate production of lymphangiogenic/angiogenic factors during inflammatory insults and can stimulate proliferation, migration, and tube formation of LEC in vitro in a paracrine manner.publishedVersio

Oral health-related quality of life in 4-16-year-olds with and without juvenile idiopathic arthritis

Background: Few studies have investigated oral health-related quality of life (OHRQoL) in young individuals with juvenile idiopathic arthritis (JIA). Aims were to investigate whether OHRQoL differs between children and adolescents with JIA compared to controls without JIA, while adjusting for socio-demographic-, behavioral- and oral health-related covariates. Furthermore, to explore whether socio-behavioral and oral health-related covariates of OHRQoL vary according to group affiliation and finally, specifically for individuals with JIA, to investigate whether disease-specific features associate with OHRQoL. We hypothesized that participants with JIA have poorer OHRQoL compared to participants without JIA. Methods: In this comparative cross-sectional study participants with JIA (n = 224) were matched to controls without JIA (n = 224). OHRQoL was assessed according to Early Childhood Oral Health Impact Scale (ECOHIS) (4–11-years-olds) and the child version of Oral Impacts on Daily Performances (Child-OIDP) (12–16-years-olds). JIA-specific characteristics were assessed by pediatric rheumatologists and socio-demographic, behavioral and self-reported oral health information collected by questionnaires. Index teeth were examined for caries by calibrated dentists. Multiple variable analyses were performed using logistic regression, reporting odds ratio (OR) and 95% confidence interval (CI). Two-way interactions were tested between group affiliation and the socio-behavioral- and oral health-related variables on the respective outcome variables. Results: In total, 96 participants with JIA and 98 controls were evaluated according to ECOHIS, corresponding numbers for Child-OIDP was 125 and 124. Group affiliation was not associated with impaired ECOHIS or Child-OIDP in adjusted analyses (OR = 1.95, 95% CI 0.94–4.04 and OR = 0.99, 95% CI 0.46–2.17, respectively). Female adolescents with JIA were more likely than males to report oral impacts according to Child-OIDP. Continued activity or flare was found to adversely affect Child-OIDP, also self-reported outcome measures in JIA associated with Child-OIDP. Conclusions: This study did not provide consistent evidence to confirm the hypothesis that children and adolescents with JIA are more likely to have impaired OHRQoL compared to their peers without JIA. However, female adolescents with JIA were more likely than males to report impacts on OHRQoL. Furthermore, within the JIA group, adolescents with continued disease activity, flare or reporting pain, physical disability, had higher risk than their counterparts of impaired OHRQoL.publishedVersio

Vitamin D, oral health, and disease characteristics in juvenile idiopathic arthritis: a multicenter cross-sectional study

Background: Vitamin D defciency has been associated with autoimmune diseases and oral health. Knowledge about the association between vitamin D status and oral conditions in JIA is limited. We aimed to investigate vitamin D status in a cohort of Norwegian children and adolescents with JIA and possible associations between serum vitamin D levels, clinical indicators of oral health, and JIA disease characteristics. Methods: This multi-center, cross-sectional study, included individuals with JIA aged 4–16 years from three geographically spread regions in Norway. Demographic data, age at disease onset, disease duration, JIA category, disease status, medication, and vitamin D intake were registered. One blood sample per individual was analyzed for 25(OH) vitamin D, and the level of insufciency was defned asResults: Among the 223 participants with JIA, 97.3% were Caucasians, 59.2% were girls, and median age was 12.6 years. Median disease duration was 4.6 years, and 44.4% had oligoarticular JIA. Mean serum vitamin D level was 61.4 nmol/L and 29.6% had insufcient levels. Vitamin D levels did not difer between sexes, but between regions, isoBMI categories, age groups, and seasons for blood sampling. Insufcient vitamin D levels were associated with dentin caries (adjusted OR 2.89, 95% CI 1.43–5.86) and gingival bleeding (adjusted OR 2.36, 95% CI 1.10–5.01). No associations were found with active JIA disease or more severe disease characteristics. Conclusion: In our study, nearly 30% had vitamin D insufciency, with a particularly high prevalence among adolescents. Vitamin D insufciency was associated with dentin caries and gingival bleeding, but not with JIA disease activity. These results point to the need for a multidisciplinary approach in the follow-up of children with JIA, including an increased focus on vitamin D status and oral health

Expression and effects of IL-1 and TNF-α in different experimental models of dental inflammation

List of publications This thesis is based on the following papers, which will be referred to by their roman numerals throughout the text: I. Bletsa A, Heyeraas KJ, Haug SR, Berggreen E (2004): “ IL-1α and TNF-α expression in rat periapical lesions and dental pulp after unilateral sympathectomy”, Neuroimmunomodulation 11: 376-384. II. Bletsa A, Nedrebø T, Heyeraas KJ, Berggreen E (2006): “Edema in Oral Mucosa after LPS or Cytokine Exposure”, Journal of Dental Research 85(5): 442-446. III. Bletsa A, Berggreen E, Fristad I, Tenstad O, Wiig H (2006): “Cytokine signalling in rat pulp interstitial fluid and transcapillary fluid exchange during LPS-induced acute inflammation”, Journal of Physiology 573: 225- 236. IV. Bletsa A, Berggreen E, Brudvik P: “IL-1α and TNF-α expression during early phases of experimental orthodontic tooth movement”, European Journal of Oral Sciences In press

VEGFR-2 reduces while combined VEGFR-2 and -3 signaling increases inflammation in apical periodontitis

Background: In apical periodontitis, oral pathogens provoke an inflammatory response in the apical area that induces bone resorptive lesions. In inflammation, angio- and lymphangiogenesis take place. Vascular endothelial growth factors (VEGFs) and their receptors (VEGFRs) are key players in these processes and are expressed in immune cells and endothelial cells in the lesions. Objective: We aimed at testing the role of VEGFR-2 and -3 in periapical lesion development and investigated their role in lymphangiogenesis in the draining lymph nodes. Design: We induced lesions by pulp exposure in the lower first molars of C57BL/6 mice. The mice received IgG injections or blocking antibodies against VEGFR-2 (anti-R2), VEGFR-3 (anti-R3), or combined VEGFR-2 and -3, starting on day 0 until day 10 or 21 post-exposure. Results: Lesions developed faster in the anti-R2 and anti-R3 group than in the control and anti-R2/R3 groups. In the anti-R2 group, a strong inflammatory response was found expressed as increased number of neutrophils and osteoclasts. A decreased level of pro-inflammatory cytokines was found in the anti-R2/R3 group. Lymphangiogenesis in the draining lymph nodes was inhibited after blocking of VEGFR-2 and/or -3, while the largest lymph node size was seen after anti-R2 treatment. Conclusions: We demonstrate an anti-inflammatory effect of VEGFR-2 signaling in periapical lesions which seems to involve neutrophil regulation and is independent of angiogenesis. Combined signaling of VEGFR-2 and -3 has a pro-inflammatory effect. Lymph node lymphangiogenesis is promoted through activation of VEGFR-2 and/or VEGFR-3

Fracture resistance of simulated immature teeth treated with a regenerative endodontic protocol

This study aims to evaluate fracture resistance of simulated immature teeth after treatment with regenerative endodontic procedure (REP) using tricalcium silicate cements (TSCs) as cervical plugs. Bovine incisors were sectioned to standard crown/root ratio. Pulp tissue was removed and canals were enlarged to a standardized diameter. Teeth were then treated with a REP protocol consisting of NaOCl and EDTA irrigation, intracanal medication with triple-antibiotic paste for 14 days followed by a TSC cervical seal and composite restoration. Teeth were divided into groups according to the material used; Mineral-Trioxide-Aggregate (MTA), Biodentine, TotalFill. Teeth filled with guttapercha (GP) and intact teeth served as controls. All teeth subjected to an increasing compressive force (rate of 0.05 mm/s at a 45° angle to the long axis of the tooth) until fracture. All treated teeth exhibited significantly lower resistance to fracture compared to the intact teeth but no difference was found between the TSC groups (Kruskal-Wallis, Dunn’s multiple comparison, p < .05). TSCs applied at the cervical area of simulated immature teeth treated with REP did not reinforce fracture resistance

Behandlingar av vital pulpa i tänder med djupa karieslesioner

Vital pulpabehandling utförs för att bevara pulpans försvarsfunktioner och därmed undvika pulpektomi och rotfyllning som kan vara tekniskt krävande och inte alltid ger önskat resultat. European Society of Endodontology (ESE) har publicerat ett positionsdokument avseende vitalbehandling av tänder med djupa karieslesioner vilket delvis överensstämmer med de nationella riktlinjerna i de nordiska länderna. Det finns svårigheter när det gäller att bedöma pulpans status i tänder med djupa karieslesioner. Så länge karieslesionen inte har nått pulpan rekommenderas behandlingar som utförs för att undvika exponering av pulpan, såsom stegvis exkavering. Å andra sidan, när pulpan exponerats på grund av karies, skiljer sig rekommendationerna något åt mellan ESE och de nationella riktlinjerna i de nordiska länderna. Detta beror troligen på avsaknad av evidens som talar för fördelar av den ena behandlingen framför den andra och på grund av svårigheterna att bedöma vilka exponerade pulpor som är irreversibelt skadade. Minimalinvasiva behandlingsstrategier som använder sig av nyligen utvecklade hydrauliska kalciumsilikatcement visar lovande resultat vid vitalbehandling av pulpa. Vital pulpabehandling vidareutvecklas och förändringar i de kliniska rekommendationerna är att förvänta.Vital pulp treatments (VPT) are performed to preserve the defense functions of the pulp, and thus to avoid pulpectomy and root filling, which can be technically demanding and do not always result in the desired outcome. The European Society of Endodontology (ESE) has published a position paper on VPT in teeth with deep carious lesions, which partly s to national guidelines in Nordic countries. There are unsolved difficulties in assessing the pulpal status in teeth with deep carious lesions. If the carious lesion has not reached the pulp, treatments performed to avoid pulp exposure, such as stepwise excavation, are recommended. On the other hand, when the pulp is exposed due to caries, the recommendations vary between the ESE and the national Nordic countries guidelines. This is most probably due to the lack of evidence favoring one treatment over the other, and due to difficulties in assessing, which exposed pulps are irreversibly damaged. Minimally invasive management strategies with recently developed hydraulic calcium silicate cements show promising results for VPTs aimed at avoiding root canal treatment. VPTs will be further developed and changes to clinical recommendations are anticipated

Fracture resistance of simulated immature teeth treated with a regenerative endodontic protocol

This study aims to evaluate fracture resistance of simulated immature teeth after treatment with regenerative endodontic procedure (REP) using tricalcium silicate cements (TSCs) as cervical plugs. Bovine incisors were sectioned to standard crown/root ratio. Pulp tissue was removed and canals were enlarged to a standardized diameter. Teeth were then treated with a REP protocol consisting of NaOCl and EDTA irrigation, intracanal medication with triple-antibiotic paste for 14 days followed by a TSC cervical seal and composite restoration. Teeth were divided into groups according to the material used; Mineral-Trioxide-Aggregate (MTA), Biodentine, TotalFill. Teeth filled with guttapercha (GP) and intact teeth served as controls. All teeth subjected to an increasing compressive force (rate of 0.05 mm/s at a 45° angle to the long axis of the tooth) until fracture. All treated teeth exhibited significantly lower resistance to fracture compared to the intact teeth but no difference was found between the TSC groups (Kruskal-Wallis, Dunn’s multiple comparison, p < .05). TSCs applied at the cervical area of simulated immature teeth treated with REP did not reinforce fracture resistance

Dental erosive wear in primary teeth among five-year-olds–Bergen, Norway

Objective To estimate the prevalence of dental erosive wear among five-year-olds in Bergen, Norway, and to investigate associations between background factors and the condition. Methods A total of 387 children received a dental examination in five Public Dental Service clinics in Bergen, Norway. The parents responded to items about the children’s dental hygiene and drinking habits, type of beverage container, diet, and other habits, and about their own age, educational level and country of origin. We explored background variables for possible associations with the outcome status as worst affected by erosive wear (19.4%, n = 75). Chi-squared statistics and logistic regression (Odds Ratios (OR): 95% Confidence Intervals (CI), served as statistical tools). Results Approximately 80% showed erosive wear (by SEPRS and by adopted diagnostic instrument (78.5% vs 79.8%)). The condition affected maxillary anterior teeth in 13.9% (n = 54), and cuppings in molars in 79.3% (n = 307) of cases. Grinding teeth during the day and/or night (OR: 1.87, CI: 1.07–3.25) and male sex (OR: 1.76, CI: 1.05–2.96) significantly related to outcome status as worst affected by erosive wear, respectively. Conclusion Dental erosive wear was widespread. Grinding teeth and male sex associated with outcome status as worst affected by erosive wear