Contribution of initial lymphatics to oral wound healing after tooth extraction.

Lymphatics are involved in the resolution of inflammation and wound healing, but their role in the oral wound healing process after tooth extraction has never been investigated. We therefore sought to evaluate the healing process following the extraction of maxillary molars in two transgenic mouse models: K14-VEGFR3-Ig mice, which lack initial mucosal lymphatic vessels, and K14-VEGFC mice, which have hyperplastic mucosal lymphatics. Maxillary molars were extracted from both transgenic mouse types and their corresponding wild-type (WT) controls. Mucosal and alveolar bone healing were evaluated. A delayed epithelialization and bone regeneration were observed in K14-VEGFR3-Ig mice compared with their WT littermates. The hampered wound closure was accompanied by decreased levels of epidermal growth factor (EGF) and persistent inflammation, characterized by infiltrates of immune cells and elevated levels of pro-inflammatory markers in the wounds. Hyperplastic mucosal lymphatics did not enhance the healing process after tooth extraction in K14-VEGFC mice. The findings indicate that initial mucosal lymphatics play a major role in the initial phase of the oral wound healing process.

Traumatic dental injuries: Knowledge assessment of dentists in the Norwegian Public Dental Service of Vestland.

BACKGROUND/AIM: Most children and adolescents in Norway attend the Public Dental Service (PDS) where they are treated free-of-charge until the age of 19 years. Thus, general dentists employed in the PDS are the primary care providers for traumatic dental injuries (TDI) in young patients. This cross-sectional study assessed the knowledge of PDS general dentists on the acute management and follow-up of TDI and its socio-demographic and attitudinal covariates. MATERIALS AND METHODS: All general dentists employed in the Vestland County PDS, Western Norway, (N = 170) received an online questionnaire. Socio-demographic and professional profiles of respondents as well as attitudinal indicators were queried. Clinical case scenarios on emergency treatment and further follow-ups of TDI were used to calculate a dental trauma knowledge score (DTKS; range: 0-21). Mann-Whitney U tests and Kruskal-Wallis tests determined differences between the demographic subgroups. Logistic regressions determined the potential of single factors in explaining the variability in dental trauma knowledge. RESULTS: The response rate was 46%. Most participants (60.5%) had not participated in a TDI course after graduation but would like such a course (84.2%). Mean DTKS was 13.82 (±2.6). Knowledge scores differed significantly between age groups (p = .014) and years since graduation (p = .0018). Younger dentists and recently graduated dentists scored highest. Dentists under the age of 30 years scored higher than 30-39- and 40-49-year-old dentists in these areas: emergency treatment of crown fractures with pulp exposure, identification of complications after avulsion, and management of severe intrusive luxation injury. CONCLUSION: Younger dentists had a higher theoretical knowledge of TDI. Continuing professional development among dentists in the Norwegian PDS is needed for emergency treatment and complication management after TDI.

Serum and salivary inflammatory biomarkers in juvenile idiopathic arthritis-an explorative cross-sectional study.

BACKGROUND: Biomarkers may be useful in monitoring disease activity in juvenile idiopathic arthritis (JIA). With new treatment options and treatment goals in JIA, there is an urgent need for more sensitive and responsive biomarkers. OBJECTIVE: We aimed to investigate the patterns of 92 inflammation-related biomarkers in serum and saliva in a group of Norwegian children and adolescents with JIA and controls and in active and inactive JIA. In addition, we explored whether treatment with tumor necrosis factor inhibitors (TNFi) affected the biomarker levels. METHODS: This explorative, cross-sectional study comprised a subset of children and adolescents with non-systemic JIA and matched controls from the Norwegian juvenile idiopathic arthritis study (NorJIA Study). The JIA group included individuals with clinically active or inactive JIA. Serum and unstimulated saliva were analyzed using a multiplex assay of 92 inflammation-related biomarkers. Welch's t-test and Mann-Whitney U-test were used to analyze the differences in biomarker levels between JIA and controls and between active and inactive disease. RESULTS: We included 42 participants with JIA and 30 controls, predominantly females, with a median age of 14 years. Of the 92 biomarkers, 87 were detected in serum, 73 in saliva, and 71 in both biofluids. A pronounced difference between serum and salivary biomarker patterns was found. Most biomarkers had higher levels in serum and lower levels in saliva in JIA versus controls, and in active versus inactive disease. In serum, TNF and S100A12 levels were notably higher in JIA and active disease. The TNF increase was less pronounced when excluding TNFi-treated individuals. In saliva, several biomarkers from the chemokine family were distinctly lower in the JIA group, and levels were even lower in active disease. CONCLUSION: In this explorative study, the serum and salivary biomarker patterns differed markedly, suggesting that saliva may not be a suitable substitute for serum when assessing systemic inflammation in JIA. Increased TNF levels in serum may not be a reliable biomarker for inflammatory activity in TNFi-treated children and adolescents with JIA. The lower levels of chemokines in saliva in JIA compared to controls and in active compared to inactive disease, warrant further investigation.

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.

Dental plaque and gingival bleeding in adolescents with juvenile idiopathic arthritis and controls: a multilevel analysis.

OBJECTIVE: To explore whether plaque and gingival bleeding are more frequently experienced by adolescents with juvenile idiopathic arthritis (JIA) compared to matched controls without JIA; explore whether surface- and site-specific periodontal outcomes vary between the two groups; and for participants with JIA, investigate associations between disease-specific features and periodontal outcomes. MATERIAL AND METHODS: In this comparative cross-sectional study, selected surfaces, and sites of index teeth in 10-16-year-olds with JIA and matched controls were examined by modified versions of Simplified Oral Hygiene Index (OHI-S) and Gingival Bleeding Index (GBI). Mixed-effects logistic regressions, reporting odds ratios (OR) with 95% confidence interval (CI), were applied. Intra-class correlation coefficients (ICCs) were calculated to quantify the degree of dependency of measures within the same individual. RESULTS: 144 and 159 adolescents with JIA were evaluated according to OHI-S and GBI; corresponding numbers of controls were 154 and 161. Plaque and gingival bleeding were more frequent in individuals with JIA than controls. Adjusted analyses showed association between JIA status and OHI-S > 0 (OR = 2.33, 95% CI: 1.47 - 3.67, ICC = 0.45) and GBI > 0 (OR = 1.54, 95% CI: 1.10 - 2.16, ICC = 0.41 and 0.30). Surface-specific distribution of plaque varied among the two groups. CONCLUSIONS: Our results highlight the importance of increased awareness of oral health care in patients with JIA and that surface- and site-specific differences in periodontal outcomes exist between individuals with JIA and controls. Few JIA disease-specific variables associated with plaque or gingival bleeding.

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.

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

BACKGROUND: Vitamin D deficiency 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 insufficiency was defined as < 50 nmol/L. A clinical oral examination was performed applying commonly used indices in epidemiological studies of dental caries, dental erosion, enamel defects, gingival bleeding, and oral hygiene. Serum vitamin D was used as exposure variable in multivariable regression analyses to estimate the associations between insufficient vitamin D level, JIA disease status, and oral conditions, with adjustments for age, sex, geographical region, BMI, seasonal blood sampling, and parental education. RESULTS: 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 insufficient levels. Vitamin D levels did not differ between sexes, but between regions, iso-BMI categories, age groups, and seasons for blood sampling. Insufficient 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 insufficiency, with a particularly high prevalence among adolescents. Vitamin D insufficiency 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.

Dental caries in children and adolescents with juvenile idiopathic arthritis and controls: a multilevel analysis.

BACKGROUND: Optimal utilization of dental caries data is crucial in epidemiological research of individuals with juvenile idiopathic arthritis (JIA). The aims were to: explore whether caries is more prevalent among children and adolescents with JIA compared to controls; examine presence of caries according to JIA group, socio-behavioral and intraoral characteristics, and the extent to which surface-specific caries varies between and within individuals; assess whether surface-specific caries varies according to JIA group and dentition; and investigate whether disease-specific clinical features of JIA are associated with presence of caries. METHODS: In this comparative cross-sectional study, calibrated dentists examined index teeth (primary 2. molars, 1. permanent molars) of 4-16-year-olds with JIA (n = 219) and matched controls (n = 224), using a detailed caries diagnosis system (including enamel caries). JIA-specific characteristics were assessed by pediatric rheumatologists and socio-behavioral information collected by questionnaires. Multilevel mixed-effect logistic regressions reporting odds ratios (OR) with 95% confidence interval (CI) were applied (caries at surface level as outcome variable). Potential confounders were adjusted for, and the effect of dependency of surface-specific caries data was estimated by calculating intra-class correlation coefficients (ICC). RESULTS: At individual level, no significant difference in caries prevalence was found between individuals with JIA and controls, regardless of inclusion of enamel caries. Proportion of enamel lesions exceeded dentine lesions. JIA was not associated with presence of caries, but in both groups, low maternal educational level was associated with presence of caries (OR: 2.07, 95% CI: 1.24-3.46). Occlusal and mesial surfaces, compared to buccal surfaces, had generally higher OR according to presence of caries than distal and lingual surfaces (ICC = 0.56). Surface-specific caries in the permanent dentition differed significantly according to group affiliation. Some JIA disease-specific variables were suggested to associate with presence of caries. CONCLUSIONS: No overall difference in caries prevalence between individuals with JIA and controls was observed, but for both groups, low maternal educational level and tooth surface associated with presence of caries. Associations between JIA disease-specific variables and presence of caries cannot be excluded. Due to predominance of enamel lesions, the potential of preventative dental strategies is considerable.

Differential Responses of Human Dental Pulp Stromal Cells to Bioceramic Materials: A Comparative In Vitro Study.

AIM: The aim of this study was to compare the effects of white MTA-Angelus (wMTA), Biodentine® (Biodentine) and TotalFill® BC Root Repair MaterialTM putty (TotalFill) on human dental pulp stromal cells (hDPSCs) in vitro. MATERIALS AND METHODS: hDPSCs were isolated from third molars of healthy young adults. Material elutes at different concentrations were prepared. Cells were exposed to the eluates for 1, 3, and 7 days. Cell proliferation was evaluated using 3-(4,5-dimethyl-thiazoyl)-2, 5-diphenyl-tetrazolium bromide assay. The expression of alkaline phosphatase (ALP), osteoprotegerin (OPG), osteocalcin (OC), collagen1A (Col1A), runt-related transcription factor 2 (RUNX2), vascular endothelial growth factor-A (VEGF-A), fibroblast growth factor-1 (FGF-1), interleukin 6 (IL6), tumor necrosis factor alpha (TNFα), and interleukin-1-beta (IL1ß) was determined by reverse transcription-polymerase chain reaction (RT-PCR). VEGF-A protein levels and ALP activity were quantified in the culture supernatant. Data were analyzed by two-way analysis of variance (ANOVA). p values <0.05 were considered statistically significant. RESULTS: hDPSC proliferation was decreased in a dose-related manner for all materials on day 3. The same effect was observed with wMTA and TotalFill on day 7. RT-PCR showed that Biodentine increased the expression of the osteogenic markers ALP, OPG, and OC. TotalFill decreased the ALP expression and activity, enhanced the production of angiogenic VEGF-A, and downregulated the inflammatory IL6 on day 7. CONCLUSION: Although the tested materials are used interchangeably in vital pulp therapy, the findings showed varied hDPSC responses. Biodentine did not affect cell proliferation and increased the expression of osteo-/odontogenic markers compared to wMTA and TotalFill, whereas TotalFill decreased cell proliferation and exhibited enhanced angiogenic and anti-inflammatory effects over time. CLINICAL SIGNIFICANCE: The clinical significance of the results needs further investigation in an attempt to provide recommendations on the selection of bioceramic pulp capping material under different scenarios of pulpal pathosis.

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.

Using Cone-beam CT in Diagnosis and Management of Severe Dilaceration Following Trauma in Primary Teeth: A Case Report.

AIM: This case report illustrates the multidisciplinary treatment of a 12-year-old boy with esthetic challenges and endodontic problems in his maxillary incisors after severe dental injury at the age of 2½ years. BACKGROUND: The close anatomic relationship of the primary tooth to the permanent tooth germ explains why traumatic dental injuries in primary dentition may affect the development of permanent teeth especially in the maxillary anterior region. Developmental defects of enamel (DDE) as well as crown/root dilacerations are often seen after displacement injuries such as intrusion or avulsion occurring at lower age. CASE DESCRIPTION: A 12-year-old boy with severe discoloration and enamel hypoplasia of his maxillary incisors was treated with composite restorations. History of avulsion injury of teeth 51 and 61 at the age of 2½ years explained the DDE, the severe dilaceration, and delayed tooth eruption of tooth 21. Use of cone-beam computed tomography (CBCT) was decisive in diagnosis and treatment planning of esthetic concerns and endodontic complications. CONCLUSION: Trauma to primary teeth taking place at early childhood may have severe consequences on permanent successors. CLINICAL SIGNIFICANCE: Severe morphological variations in permanent incisors caused by dental injuries in the predecessor teeth require monitoring and multidisciplinary approach. Advanced three-dimensional radiographic imaging is useful in identification and treatment planning of such cases. HOW TO CITE THIS ARTICLE: Bletsa A, Bessonova MV, Iden O. Using Cone-beam CT in Diagnosis and Management of Severe Dilaceration Following Trauma in Primary Teeth: A Case Report. Int J Clin Pediatr Dent 2020;13(S-1):S110-S114.

Oral health in children and adolescents with juvenile idiopathic arthritis - a systematic review and meta-analysis.

BACKGROUND: Observational studies examining the association between oral health and juvenile idiopathic arthritis (JIA) among children and adolescents have reported inconsistent findings. The aims of this systematic review and meta-analysis were to ascertain a potential difference in oral health and oral health-related quality of life (OHRQoL) among children and adolescents with JIA and healthy peers, and to assess the association of prevalence of oral diseases/conditions, temporomandibular disorders (TMD), including temporomandibular joint (TMJ) diseases, in relation to activity and severity of JIA. METHOD: Medline Ovid, Embase, CINAHL, SweMed+ and Cochrane Library were searched up to 25 November 2018. All articles published in English, German and Scandinavian languages focusing on children and adolescents with JIA and without JIA in relation to oral health measures, were considered. Two authors independently evaluated observational studies for inclusion. The study quality was assessed using modified Newcastle Ottawa Scale. Meta-analysis was performed for studies focusing on dental caries as an outcome. RESULTS: Nineteen articles met the inclusion criteria, covering a range of oral diseases/conditions and OHRQoL. Eighteen studies had cross-sectional design. No mean difference of dmft/DMFT indices (decayed/missed/filled teeth) was observed between the JIA - and healthy group. None of the oral health measures including dental erosive wear, enamel defects, dental maturation and OHRQoL, indicated better oral health among children and adolescents with JIA compared to healthy group. However, periodontal conditions and TMD were more predominant among children and adolescents with JIA compared to healthy peers. CONCLUSIONS: Based on the cross-sectional studies, periodontal diseases and TMD were found to be more frequent in children and adolescents with JIA compared to healthy peers. Furthermore, more high-quality studies with large sample size are needed before we infer any concrete conclusion regarding the association between the prevalence of oral and TMJ diseases or oral conditions in relation to activity and severity of JIA.

Work experience influences treatment approaches in endodontics: a questionnaire survey among dentists in Western Norway.

Objectives: To collect information on endodontic treatment procedures among dentists in the public dental service (PDS) in Western Norway and relate this information to their work experience. Materials and methods: A survey comprised of 35 questions related to personal information, frequency of endodontic treatment, endodontic procedures and treatment principles was distributed electronically to 187 dentists in PDS in two counties of Western Norway. Results: The response rate was 74%, and 130 dentists participated. Among them, 57.0% had completed their education less than 13 years ago, and almost all were below 39 years old (95%). The majority (81.0%) had graduated in Norway. Stepwise caries excavation in primary and permanent teeth and direct pulp capping in primary teeth were more frequently performed by dentists with less than 13 years from graduation. Routine use of rubber dam was high among the responders (87%). However, use of rubber dam and master-cone radiograph uptakes were more frequent among the younger dentists. The majority used rotary instrumentation systems, and almost all participants followed the current guidelines for use of antibiotics in endodontics. Conclusions: In general, dentists in PDS follow the current endodontic treatment guidelines. However, it seems that the more recently graduated dentists perform more endodontic procedures and tend to adhere more to the taught principles regarding rubber dam use and radiograph uptakes.

Tricalcium silicate cements: osteogenic and angiogenic responses of human bone marrow stem cells.

Tricalcium silicate cements (TSCs) are used in endodontic procedures to promote wound healing and hard tissue formation. The aim of this study was to evaluate and compare the effect of commonly used TSCs [mineral trioxide aggregate (MTA), Biodentine, and TotalFill] on cellular metabolism and osteogenic/angiogenic differentiation of human bone marrow mesenchymal stem cells (hBMSCs) in vitro. We tested the null hypothesis of no difference between MTA, Biodentine, and TotalFill in stem cell responses. Cells were subjected to eluates of the tested materials for up to 14 d. Cell viability was evaluated using the 3-(4,5-dimethyl-thiazoyl)-2,5-diphenyl-tetrazolium bromide (MTT) assay. Real-time PCR was used to determine the levels of expression of the osteogenic factors alkaline phosphatase (ALP), osteoprotegerin (OPG), osteocalcin (OC), and collagen 1A (COL1A1), and the angiogenic factors vascular endothelial growth factor A (VEGFA) and fibroblast growth factor 1 (FGF1). ELISAs were used to measure the levels of VEGFA and ALP in culture supernatants. Mineralization in vitro of hBMSCs was assessed using Alizarin Red staining. The hBMSCs tolerated exposure to TSCs well, with Biodentine showing the most favorable effect on cell viability. Expression of ALP, COL1A1, OPG, and VEGFA were differentially affected by the materials, with Biodentine and TotalFill inducing earlier changes at gene level. Increased mineralization was observed with time, after exposure to all TSCs tested, with MTA showing the greatest effect. The results revealed different responses of hBMSCs to TSCs in vitro.

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.

Lymphatic growth factors are expressed in human gingiva and upregulated in gingival fibroblasts after stimulation.

BACKGROUND: The lymphatic growth factors vascular endothelial growth factor (VEGF)-C and -D are important for maintenance and growth of lymphatic vessels (lymphangiogenesis), but their localization in human gingiva is unknown. This study investigated the expression of VEGF-C and -D in human gingiva and isolated human gingival fibroblasts (HGFs). In addition, the localization of their main receptor VEGFR-3 was explored. METHODS: Non-inflamed gingiva from six donors was used for immunohistochemistry or isolation of HGFs. HGFs were stimulated with either E.coli lipopolysaccharide (LPS) or IL-6/soluble IL-6 receptor (sIL-6R) complex for 1, 6, and 24 hours. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to quantify the relative changes in gene expression of VEGF-A, -C, and -D and enzyme-linked immunosorbent assay (ELISA) for quantification of protein levels. RESULTS: VEGF-C, -D and VEGFR-3 were seen in keratinocytes, blood vessels and in scattered single cells in gingiva. VEGFR-3 was also found in lymphatic vessels and VEGF-C in cells with fibroblastic appearance. Gene analysis showed no expression of VEGF-D in the HGFs, but showed constitutive expression of VEGF-C and -A. Stimulation of HGFs with LPS or IL-6/sIL-6R complex was followed by gene upregulation of VEGF-C and -A and increased protein levels in cell culture supernatant (P ≤0.05). CONCLUSIONS: The localization of VEGF-C, -D, and VEGFR-3 expression imply that signaling via VEGFR-3 is linked to vascular homeostasis and keratinocyte function under normal conditions in gingiva. Inflammatory stimulation of HGFs upregulates VEGF-C and -A expression and may contribute to angiogenesis and lymphangiogenesis.

Secretoneurin and PE-11 immunoreactivity in the human dental pulp.

OBJECTIVE: To explore whether there are differences in the concentration of the secretogranin II-derived peptide secretoneurin and the chromogranin B-derived peptide PE-11 between the healthy and inflamed human dental pulps. Furthermore, colocalization studies with calcitonin gene-related peptide were performed to confirm the sensory origin of the peptidergic nerves in the dental pulp. DESIGN: The concentrations of secretoneurin and PE-11 were determined by highly sensitive radioimmunoassays in extracts of dental pulps, the molecular form of secretoneurin immunoreactivities by RP-HPLC with subsequent radioimmunoassay and colocalization studies with calcitonin gene-related peptide were performed by double immunofluorescence. RESULTS: Only secretoneurin but not PE-11 was detectable by radioimmunoassays whereas nerve fibers could be made visible for both secretoneurin and PE-11. Furthermore, there was a full colocalization of secretoneurin and PE-11 with calcitonin gene-related peptide in immunohistochemical experiments. There were no differences in the concentration of secretoneurin between the healthy and inflamed human dental pulp and moreover, the characterization of the secretoneurin immunoreactivities revealed that only authentic secretoneurin was detected with the secretoneurin antibody. CONCLUSIONS: There is unequivocal evidence that secretoneurin and PE-11 are constituents of the sensory innervation of the human dental pulp and although not exclusively but are yet present in unmyelinated C-fibers which transmit predominantly nociceptive impulses. Secretoneurin might be involved in local effector functions as well, particularly in neurogenic inflammation, given that this is the case despite of unaltered levels in inflamed tissue.

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.

Localization and signaling patterns of vascular endothelial growth factors and receptors in human periapical lesions.

INTRODUCTION: Vascular endothelial growth factors (VEGFs) and their receptors (VEGFRs) are key players in vasculogenesis and are also involved in pathologic conditions with bone destruction. Vasculogenesis is critical for disease progression, and bone resorption is a hallmark of apical periodontitis. However, the localization of VEGFs and VEGFRs and their gene signaling pathways in human apical periodontitis have not been thoroughly investigated. The aim of this study was to localize VEGFs and VEGFRs and analyze their gene expression as well as signaling pathways in human periapical lesions. METHODS: Tissue was collected after endodontic surgery from patients diagnosed with chronic apical periodontitis. Periodontal ligament samples from extracted healthy wisdom teeth was also collected and used as control tissue. In lesion cryosections, VEGFs/VEGFRs were identified by immunohistochemistry/double immunofluorescence by using specific antibodies. A human VEGF signaling polymerase chain reaction array system was used for gene expression analysis comparing lesions with periodontal ligament samples. RESULTS: The histologic evaluation revealed heterogeneous morphology of the periapical lesions with various degrees of inflammatory infiltrates. In the lesions, all investigated factors and receptors were identified in blood vessels and various immune cells. No lymphatic vessels were detected. Gene expression analysis revealed up-regulation of VEGF-A and VEGFR-3, although not significant. Phosphatidylinositol-3-kinases, protein kinase C, mitogen-activated protein kinases, and phospholipases, all known to be involved in VEGF-mediated angiogenic activity, were significantly up-regulated. CONCLUSIONS: The cellular and vascular expressions of VEGFs and VEGFRs in chronic apical periodontitis, along with significant alterations of genes mediating VEGF-induced angiogenic responses, suggest ongoing vascular remodeling in established chronic periapical lesions.

Vascular endothelial growth factors signalling in normal human dental pulp: a study of gene and protein expression.

In the well-vascularized dental pulp vascular endothelial growth factor A (VEGF-A) is expressed. Vascular endothelial growth factor A is a member of the VEGF family, which includes VEGFs-B, -C, and -D. The latter three have not been investigated in the pulp. Vascular endothelial growth factors C and D are the only ligands for vascular endothelial growth factor receptor (VEGFR)-3, which is usually expressed in lymphatic endothelium. They can also activate VEGFR-2, the main angiogenic receptor. We aimed to study VEGFs signalling in human dental pulp at the gene level and to identify the cellular source for protein expression using immunolabelling. All VEGFs (-A, -B, -C, and -D) were expressed in the pulp and may exert both autocrine and paracrine effects in blood vessels and immune cells found to be equipped with VEGFRs-2 and -3. Lymphatic vessel endothelial hyaluronan receptor-positive macrophages, known to be involved in angiogenesis, were found in the pulp, whereas lymphatic vessels were not detected. Twenty-six of 84 VEGF signalling genes, including VEGFR-3, were expressed at a significantly higher level in the pulp than in the control periodontal ligament. In conclusion, the normal human pulp represents a tissue with relatively high VEGF signalling involving both immune responses and vascular activity.