Oral health-related quality of life of patients after solid organ transplantation is not affected by oral conditions: results of a multicentre cross-sectional study.

BACKGROUND: This multicentre cross-sectional study aimed in examination of oral health-related quality of life (OHRQoL) of patients after solid organ transplantation (SOT). MATERIAL AND METHODS: Patients after SOT (liver, lung and heart) at one out of three German centers (Goettingen, Essen, Leipzig) were included. For comparison, a healthy control (HC) was recruited. OHRQoL was assessed by German short form of oral health impact profile (OHIP G14). Oral examination comprised: decayed-, missing- and filled-teeth index (DMF-T), remaining teeth and periodontitis severity. RESULTS: In total, 196 patients after SOT and 130 HC with comparable age, gender and smoking habits were included (p>0.05). DMF-T and number of remaining teeth was worse in SOT group (p<0.01). OHIP G14 sum score was significantly higher in SOT (3.49 ± 5.73 vs. 1.33 ± 2.63, p<0.01). In contrast to HC, in SOT no associations between OHIP G14 and oral health parameters were found (pi>0.05). Number of remaining teeth was not an independent predictor of OHIP G14 sum score in SOT (ß -0.082, CI95 -0.156 - 0.045, p=0.28). CONCLUSIONS: OHRQoL of SOT recipients is not affected by their oral condition, leading to the assumption that the individual perception of patients physical oral health is not in line with the clinical situation.

Oral health and oral health-related quality of life in patients with oral dystonia indicates their need for dental special care.

BACKGROUND: This retrospective study aimed in the evaluation of oral health and oral health-related quality of life (OHRQoL) of patients with oral dystonia (OD). MATERIAL AND METHODS: Seventeen patients with OD (Meige Syndrome: n=11, Oromandibular Dystonia: n=6) were included, of which seven were examined again at three months after botulinum toxin injection. OHRQoL was assessed by the German short form of oral health impact profile (OHIP G14). Within oral examination, dental parameters, remaining teeth and periodontitis severity were assessed. A matched healthy control (HC) was composed for comparison. RESULTS: The OD patients had significantly more carious teeth (0.94 ± 1.75 vs. 0; p<0.01), less remaining teeth (15.65 ± 9.89 vs. 22.22 ± 5.91; p=0.01) and higher dental treatment need than the HC (42.9% vs. 0%; p<0.01). The OHIP G14 sum score of 9.47± 9.82 vs. 1.58 ± 2.79 (p<0.01) as well its dimensions psychosocial impact (4.47 ± 6.45 vs. 0.53 ± 1.16; p=0.03) and oral function (4.35 ± 2.98 vs. 0.47 ± 1.34; p<0.01) were clinically relevant and statistically significant higher in OD compared to HC group. No significant differences could be detected at three months after botulinum toxin injection. CONCLUSIONS: Patients with OD suffer from more dental diseases and have a worse OHRQoL than HC. Dental special care appears recommendable and should be fostered by everyone, who is involved in the treatment of patients with OD.

Efficiency of desensitizing materials in xerostomic patients with head and neck cancer: a comparative clinical study.

OBJECTIVES: To assess the clinical effectiveness of four desensitizing materials in patients who are xerostomic due to radiotherapy for head and neck cancer (HNC) in comparison to a healthy group with normal salivation. METHODS AND MATERIALS: The study was conducted as a split-mouth randomized clinical trial. Forty HNC patients (group A) and 46 healthy patients (group B) suffering from dentin hypersensitivity (DH) were included. Salivary flow was determined through a scialometric test. Hypersensitivity was assessed with air stimulus and tactile stimulus. The materials used as desensitizing agents were Vertise Flow, Universal Dentin Sealant, Clearfil Protect Bond, and Flor-Opal Varnish. The response was recorded before application of the materials, immediately after, and at 1 week, 4 weeks, and 12 weeks. RESULTS: Salivary flow rates in groups A/B were 0.15/0.53 mL/min (unstimulated) and 0.54/1.27 mL/min (stimulated), respectively. In group A, 100 hypersensitive teeth were included. Application of the desensitizing agents significantly decreased the hypersensitivity immediately and throughout the 4-week follow-up (p < 0.001). However, after the 12-week timepoint, a loss of efficacy was detected in all agents (p = 0.131). In group B, 116 hypersensitive teeth were included. The materials performed a more stable action, although a loss of effectiveness was detected at 12-week control (p = 0.297). CONCLUSION: The efficiency of the desensitizing agents after the first application was similar in both groups. In the radiated group, this effect lasted for shorter periods than in healthy controls. CLINICAL RELEVANCE: HNC patients with hyposalivation may be a new risk group for DH.

Association of cytokine patterns and clinical/laboratory parameters, medication and periodontal burden in patients with rheumatoid arthritis (RA).

To evaluate serum levels of the following cytokines in rheumatoid arthritis subjects with periodontal disease: Interleukin-6, -10, -17, and -23. Patients with rheumatoid arthritis frequently suffer from periodontal disease. Both diseases partly result from a dysregulated immune response. The current study aimed to quantify Interleukin-6, -10, -17, and -23 levels in rheumatoid arthritis. It should be investigated if the periodontal disease would have additional modifying effects. A total of 157 patients were included. Serum levels of IL-6, -10, -17, and -23 were measured by ELISA. Serum IL-10 increased with longer duration of morning stiffness and with higher rheumatoid factor and anti-cyclic citrullinated peptide titres. IL-10 was also elevated with longer duration of prednisolone (< 5 mg daily) and leflunomide therapy. Subjects with lower erythrocyte sedimentation rate/longer leflunomide therapy displayed more missing teeth/more clinical attachment loss. IL-17 was higher in subjects with fewer missing teeth if the following criteria were fulfilled: shorter prednisolone (< 5 mg) and methotrexate therapy, more swollen joints, longer morning stiffness. IL-23 finally was increased in subjects with higher rheumatoid factor and in those with higher periodontal probing depth/clinical attachment loss in the following situations: lower rheumatoid factor and shorter leflunomide therapy. Subjects suffering from dental/periodontal burden show an aberrant systemic cytokine availability of serum IL-6, IL-10, IL-17 and IL-23 related to disease activity and medication. This examination underlines the complexity of potential interactions between disease activity and medication related to periodontal burden.

High prevalence of periodontitis in blood donors and the possibility of questionnaire-based screening - results of a cross-sectional study.

BACKGROUND: Periodontitis is an inflammatory disease of high prevalence and, thus, of potential relevance to the management of blood donation. OBJECTIVES: The aim of this cross-sectional study was to assess periodontal health and its associations to common blood parameters, as well as questionnaire-based periodontitis screening in blood donors. METHODS: Generally healthy blood donors were recruited and underwent oral examination. Thereby, the decayed-, missing- and filled-teeth index (DMF-T) and periodontal status, including periodontal probing depth and clinical attachment loss, were assessed. Based on periodontal status, periodontitis severity was classified into no/mild, moderate or severe. Six yes/no questions regarding periodontal complaints and history were asked. Furthermore, common blood parameters were analysed. RESULTS: A total of 148 participants (mean age 53·33 years) were included. The DMF-T was 15·28 ± 6·44. Nearly three quarters of participants suffered from a periodontitis (moderate 59·5% and severe 14·8%, total periodontitis 74·3%). Periodontitis severity was associated with the history of dental visits caused by periodontal complaints (P < 0·01) and previous periodontal therapy (P < 0·01). Only procalcitonin was initially found to be associated with blood periodontitis severity (P = 0·02). This observation was not confirmed by post-hoc testing between subgroups (Pi > 0·2). No further association between periodontitis severity and blood parameters was found (Pi > 0·05). CONCLUSION: The prevalence of periodontitis in German blood donors is high. However, further studies with sensitive testing of bacteria in peripheral blood are required in order to determine the relevance of this result for the safety of blood components.

Detection of pulsed blood flow through a molar pulp chamber and surrounding tissue in vitro.

OBJECTIVES: Due to severe limitations of dental pulp sensitivity tests, the direct recording of pulsed blood flow, using photoplethysmography (PPG), has been proposed. In vivo evaluation is methodologically difficult and in vitro models have hitherto been adversely influenced by shortcomings in emulating the in vivo situation. Consequently, the aim of this study was to test an improved data acquisition system and to use this configuration for recording pulsed blood in a new model. MATERIALS AND METHODS: We introduced a PPG signal detection system by recording signals under different blood flow conditions at two wavelengths (625 and 940 nm). Pulsed blood flow signals were measured using an in vitro model, containing a molar with a glass pulp and a resin socket, which closely resembled in vivo conditions with regard to volumetric blood flow, pulp anatomy, and surrounding tissue. RESULTS: The detection system showed improved signal strength without stronger blanketing of noise. On the tooth surface, it was possible to detect signals emanating from pulsed blood flow from the glass pulp and from surrounding tissue at 625 nm. At 940 nm, pulp derived signals were recorded, without interference signals from surrounding tissue. CONCLUSION: The PPG-based method has the potential to detect pulsed blood flow in small volumes in the pulp and (at 625 nm) also in adjacent tissues. CLINICAL RELEVANCE: The results show the need for clear differentiation of the spatial origins of blood flow signals of any vitality test method to be applied to teeth.

Antimicrobial peptides as a possible interlink between periodontal diseases and its risk factors: A systematic review.

Antimicrobial peptides (AMPs) play a critical role in controlling innate and acquired immune responses. Local dysregulation of AMP is implicated in the pathogenesis of periodontal diseases as a response to periodontal pathogen challenge. Changes in AMP expression also characterize tobacco smoking, diabetes mellitus, obesity and rheumatoid arthritis, which are established risk factors of periodontal diseases, suggesting AMP may act as putative mechanistic links between these. The aim was to evaluate and summarize critically the current evidence pertaining to interrelationships between AMPs, periodontal diseases and selected periodontal disease risk factors. General and theme specific keywords were used to search the PUBMED database for studies relevant to AMP, periodontal diseases, smoking, diabetes mellitus, obesity and rheumatoid arthritis and critically reviewed. A total of 131 abstracts and 119 full text articles were screened for relevance; 13 studies were selected for inclusion after critical review. Local AMP dysregulation characteristic to periodontal diseases appears to occur within a broader landscape of complex systemic immune perturbations independently induced by smoking, metabolic and rheumatoid disease. The nature of these interactions and mechanistic pathways involved are inadequately understood. AMPs could be possible mechanistic interlinks between periodontal diseases and its risk factors. However, such evidence is very limited and more in vivo and in vitro studies are necessary to clarify the nature of such relationships. A greater understanding of AMPs as shared mediators is essential for unraveling their value as therapeutic or biomarker candidates.

Integrated analysis of long noncoding RNA-associated competing endogenous RNA network in periodontitis.

BACKGROUND AND OBJECTIVES: Long noncoding RNAs (lncRNAs) play critical and complex roles in regulating various biological processes of periodontitis. This bioinformatic study aims to construct a putative competing endogenous RNA (ceRNA) network by integrating lncRNA, miRNA and mRNA expression, based on high-throughput RNA sequencing and microarray data about periodontitis. MATERIAL AND METHODS: Data from 1 miRNA and 3 mRNA expression profiles were obtained to construct the lncRNA-associated ceRNA network. Gene Ontology enrichment analysis and pathway analysis were performed using the Gene Ontology website and Kyoto Encyclopedia of Genes and Genomes. A protein-protein interaction network was constructed based on the Search Tool for the retrieval of Interacting Genes/Proteins. Transcription factors (TFs) of differentially expressed genes were identified based on TRANSFAC database and then a regulatory network was constructed. RESULTS: Through constructing the dysregulated ceRNA network, 6 genes (HSPA4L, PANK3, YOD1, CTNNBIP1, EVI2B, ITGAL) and 3 miRNAs (miR-125a-3p, miR-200a, miR-142-3p) were detected. Three lncRNAs (MALAT1, TUG1, FGD5-AS1) were found to target both miR-125a-3p and miR-142-3p in this ceRNA network. Protein-protein interaction network analysis identified several hub genes, including VCAM1, ITGA4, UBC, LYN and SSX2IP. Three pathways (cytokine-cytokine receptor, cell adhesion molecules, chemokine signaling pathway) were identified to be overlapping results with the previous bioinformatics studies in periodontitis. Moreover, 2 TFs including FOS and EGR were identified to be involved in the regulatory network of the differentially expressed genes-TFs in periodontitis. CONCLUSION: These findings suggest that 6 mRNAs (HSPA4L, PANK3, YOD1, CTNNBIP1, EVI2B, ITGAL), 3 miRNAs (hsa-miR-125a-3p, hsa-miR-200a, hsa-miR-142-3p) and 3 lncRNAs (MALAT1, TUG1, FGD5-AS1) might be involved in the lncRNA-associated ceRNA network of periodontitis. This study sought to illuminate further the genetic and epigenetic mechanisms of periodontitis through constructing an lncRNA-associated ceRNA network.

Dialysis vintage time has the strongest correlation to psychosocial pattern of oral health-related quality of life - a multicentre cross-sectional study.

BACKGROUND: Aim of this cross-sectional, multicentre study was to investigate associations of dialysis vintage time in haemodialysis (CKD5D) patients with oral health-related quality of life (OHRQoL) and dental and periodontal treatment need. MATERIAL AND METHODS: CKD5D patients were divided into subgroups according to dialysis vintage time in different dialysis centres in Germany. OHRQoL was assessed with oral health impact profile (OHIP-G14). Dental treatment need was classified as presence of carious lesions. Periodontal treatment need was defined as periodontal screening index score (PSI) 3-4. RESULTS: In total, 190 participants were divided into the subgroups according to the time on CKD5D: 0 - 2 (n = 29), 3 - 5 (n = 35), 6 - 8 (n = 34), 9 - 12 (n = 29), 13 - 20 (n = 34) and >20 years (n = 29). The overall treatment need in the total cohort was 92% (dental 56%, periodontal 88%) with a total OHIP-G14 sum score of 4.17 [2; 0-5] without a significant correlation. Time on CKD5D was inversely correlated with the OHIP G14 score (p<0.01, R = -0.201). The pattern psychosocial impact was significantly associated with the dialysis duration (p<0.01) and showed a negative correlation to the OHIP-G14 (R = -0.283, Spearman's rho test p<0.01). For oral function also a negative correlation with OHIP-G14 was detected (Spearman's rho: -0.183). CONCLUSIONS: Patients with a prolonged dialysis vintage time show an improved OHRQoL, which might be mainly caused by the positive development of psychosocial pattern of OHRQoL. The oral health situation of HD patients seems unsatisfying, independently of dialysis vintage time and OHRQoL. Accordingly, an improvement in oral health situation of CKD5D patients is mandatory necessary. Thereby, consideration of psychosocial aspects especially at the beginning of CKD5D therapy and a sensitization regarding oral health issues with increasing vintage time might be recommendable.

Association of time under immunosuppression and different immunosuppressive medication on periodontal parameters and selected bacteria of patients after solid organ transplantation.

BACKGROUND: Aim of this study was to investigate the association of the time under immunosuppression and different immunosuppressive medication on periodontal parameters and selected periodontal pathogenic bacteria of immunosuppressed patients after solid organ transplantation (SOT). MATERIAL AND METHODS: 169 Patients after SOT (lung, liver or kidney) were included and divided into subgroups according their time under (0-1, 1-3, 3-6, 6-10 and >10 years) and form of immunosuppression (Tacrolimus, Cyclosporine, Mycophenolate, Glucocorticoids, Sirolimus and monotherapy vs. combination). Periodontal probing depth (PPD) and clinical attachment loss (CAL) were assessed. Periodontal disease severity was classified as healthy/mild, moderate or severe periodontitis. Subgingival biofilm samples were investigated for eleven selected potentially periodontal pathogenic bacteria using polymerasechainreaction. RESULTS: The mean PPD and CAL as well as prevalence of Treponema denticola and Capnocytophaga species was shown to be different but heterogeneous depending on time under immunosuppression (p<0.05). Furthermore, only the medication with Cyclosporine was found to show worse periodontal condition compared to patients without Cyclosporine (p<0.05). Prevalence of Porphyromonas gingivalis, Tannerella forsythia and Fusobacterium nucleatum was reduced and prevalence of Parvimonas micra and Capnocytophaga species was increased in patients under immunosuppression with Glucocorticoids, Mycophenolate as well as combination therapy. CONCLUSION: Time under and form of immunosuppression might have an impact on the clinical periodontal and microbiological parameters of patients after SOT. Patients under Cyclosporine medication should receive increased attention. Differences in subgingival biofilm, but not in clinical parameters were found for Glucocorticoids, Mycophenolate and combination therapy, making the clinical relevance of this finding unclear.

Active matrix metalloproteinase-8 and periodontal bacteria depending on periodontal status in patients with rheumatoid arthritis.

BACKGROUND AND OBJECTIVES: The aim of this clinical cross-sectional study was to determine the level of active matrix metalloproteinase-8 (aMMP-8) and periodontal pathogenic bacteria in gingival crevicular fluid in patients with rheumatoid arthritis (RA) with varying periodontal conditions. MATERIAL AND METHODS: In total, 103 patients with RA and 104 healthy controls (HC) were included. The assessment of periodontal status included periodontal probing depth, bleeding on probing and clinical attachment loss. Periodontal disease was classified as healthy/mild, moderate or severe. For the determination of aMMP-8 levels using enzyme-linked immunosorbent assay and periodontal pathogenic bacteria using polymerase chain reaction, samples of gingival crevicular fluid were taken from the deepest gingival pockets. The statistical analyses used included a Mann-Whitney U-test, a chi-squared test or a Fisher's exact test, and the significance level was set at α = 5%. RESULTS: We found that 65% of patients with RA and 79% of HC had moderate to severe periodontal disease (p = 0.02). The prevalence of periodontal pathogens was almost equal (p > 0.05). Furthermore, depending on periodontal disease severity only minor differences in bacterial prevalence were detected. With increasing severity of periodontal disease, higher aMMP-8 levels were observed. Accordingly, a significant difference in patients with moderate periodontal disease (RA: 15.3 ± 13.8; HC: 9.1 ± 9.1; p ≤ 0.01) and severe periodontal disease (RA: 21.7 ± 13.3; HC: 13.1 ± 8.6; p = 0.07) was detected, with a greater tendency in the latter group. CONCLUSION: The increased aMMP-8 levels in the RA group indicate that the presence of RA appears to have an influence on the host response at a comparable level of bacterial load and periodontal disease severity.

Ultrasonic activation of irrigants increases growth factor release from human dentine.

OBJECTIVES: Bioactive proteins are sequestered in human dentine and play a decisive role in dental pulp regeneration and repair. They can be released and exposed on the dentine surface by acids, but also chelators, such as ethylenediaminetetraacetic acid (EDTA). The objectives of this study were (i) to evaluate whether ultrasonic activation of irrigants in the root canal will promote growth factor release from dentine and (ii) to collect bioactive proteins in a physiological solution. MATERIALS AND METHODS: Human dentine disks underwent irrigation with and without ultrasonic activation. The protocols included treatment by either a single or two consecutive steps with 10 % EDTA and phosphate-buffered saline (PBS), where each sample was treated three times. To mimic clinical conditions, selected irrigation regimens were applied to root canals of extracted human teeth after preparation. Amounts of transforming growth factor ß1 (TGF-ß1) in solution were quantified using enzyme-linked immunosorbent assays. Nonparametric statistical analysis was performed to compare different groups as well as repetitions within a group (Mann-Whitney U test, α = 0.05). Additionally, morphological changes of dentine surfaces were visualized by scanning electron microscopy (SEM). RESULTS: TGF-ß1 was not detectable after irrigation of dentine with PBS, neither with nor without ultrasonic activation. Irrigation with EDTA released TGF-ß1, and ultrasonic activation of EDTA enhanced this effect. However, preceding EDTA conditioning enabled the release of bioactive proteins into PBS solution. Similar results were observed in dentine disks and root canals. Visualization of dentine surfaces after different treatment revealed superficial erosion after ultrasonic activation irrespective of the irrigant solution, but different degrees of exposure of organic substance. CONCLUSIONS: Ultrasonic activation enhances growth factor release from human dentine. Bioactive proteins can be isolated in physiological solvents and may act as autologous supplements for regenerative endodontic treatment or pulp tissue engineering. CLINICAL RELEVANCE: Autologous growth factors from human dentine can advance treatment strategies in dental pulp tissue engineering.

Oral health-related quality of life in patients on chronic haemodialysis and after kidney transplantation.

OBJECTIVES: The objective of the study was to evaluate oral health-related quality of life (OHRQoL) depending on dental and periodontal situation in patients on haemodialysis (HD) and after kidney transplantation (KTx) compared to healthy controls (HC). SUBJECTS AND METHODS: OHRQoL was assessed using the German short form of Oral Health Impact Profile (OHIP G14). Dental health was estimated using the decayed, missing and filled teeth index (DMF-T). Periodontal health was classified as healthy/mild or moderate/severe periodontitis. STATISTICAL ANALYSIS: Mann-Whitney U-test, Kruskal-Wallis test, chi-square test and Fisher's test. RESULTS: Eighty-seven HD patients, 39 KTx patients and 91 HC were included. Significant differences in DMF-T, D-T, M-T and F-T scores were identified between groups (P < 0.001). The prevalence of moderate/severe periodontitis was significantly higher in the HD and KTx group compared to HC (P = 0.002). Differences in OHIP G14 between groups were neither clinical relevant nor statistically significant (P = 0.199). A significant effect of DMF-T (P = 0.012), M-T (P < 0.001) and periodontitis (P = 0.023) on the OHIP G14 scores was identified only in HC. CONCLUSIONS: Improvement in dental care of HD and KTx patients is required. OHIP G14 values provide a subjectively considered low importance of oral health in HD and KTx patients, leading to need of motivation and sensitisation of these patients.

EDTA conditioning of dentine promotes adhesion, migration and differentiation of dental pulp stem cells.

AIM: To evaluate the effect of dentine conditioning on migration, adhesion and differentiation of dental pulp stem cells. METHODOLOGY: Dentine discs prepared from extracted human molars were pre-treated with EDTA (10%), NaOCl (5.25%) or H2 O. Migration of dental pulp stem cells towards pre-treated dentine after 24 and 48 h was assessed in a modified Boyden chamber assay. Cell adhesion was evaluated indirectly by measuring cell viability. Expression of mineralization-associated genes (COL1A1, ALP, BSP, DSPP, RUNX2) in cells cultured on pre-treated dentine for 7 days was determined by RT-qPCR. Nonparametric statistical analysis was performed for cell migration and cell viability data to compare different groups and time-points (Mann-Whitney U-test, α = 0.05). RESULTS: Treatment of dentine with H2 O or EDTA allowed for cell attachment, which was prohibited by NaOCl with statistical significance (P = 0.000). Furthermore, EDTA conditioning induced cell migration towards dentine. The expression of mineralization-associated genes was increased in dental pulp cells cultured on dentine after EDTA conditioning compared to H2 O-pre-treated dentine discs. CONCLUSIONS: EDTA conditioning of dentine promoted the adhesion, migration and differentiation of dental pulp stem cells towards or onto dentine. A pre-treatment with EDTA as the final step of an irrigation protocol for regenerative endodontic procedures has the potential to act favourably on new tissue formation within the root canal.

Three-dimensional culture of dental pulp stem cells in direct contact to tricalcium silicate cements.

OBJECTIVES: Calcium silicate cements are biocompatible dental materials applicable in contact with vital tissue. The novel tricalcium silicate cement Biodentine™ offers properties superior to commonly used mineral trioxide aggregate (MTA). Objective of this study was to evaluate its cytocompatibility and ability to induce differentiation and mineralization in three-dimensional cultures of dental pulp stem cells after direct contact with the material. MATERIALS AND METHODS: Test materials included a new tricalcium silicate (Biodentine™, Septodont, Saint-Maur-des-Fossés, France), MTA (ProRoot® MTA, DENSPLY Tulsa Dental Specialities, Johnson City, TN, USA), glass ionomer (Ketac™ Molar Aplicap™, 3M ESPE, Seefeld, Germany), human dentin disks and polystyrene. Magnetic activated cell sorting for to the surface antigen STRO-1 was performed to gain a fraction enriched with mesenchymal stem cells. Samples were allowed to set and dental pulp stem cells in collagen carriers were placed on top. Scanning electron microscopy of tricalcium silicate cement surfaces with and without cells was conducted. Cell viability was measured for 14 days by MTT assay. Alkaline phosphatase activity was evaluated (days 3, 7, and 14) and expression of mineralization-associated genes (COL1A1, ALP, DSPP, and RUNX2) was quantified by real-time quantitative PCR. Nonparametric statistical analysis for cell viability and alkaline phosphatase data was performed to compare different materials as well as time points (Mann-Whitney U test, α = 0.05). RESULTS: Cell viability was highest on tricalcium silicate cement, followed by MTA. Viability on glass ionomer cement and dentin disks was significantly lower. Alkaline phosphatase activity was lower in cells on new tricalcium silicate cement compared to MTA, whereas expression patterns of marker genes were alike. CONCLUSIONS: Increased cell viability and similar levels of mineralization-associated gene expression in three-dimensional cell cultures on the novel tricalcium silicate cement and mineral trioxide aggregate indicate that the material is cytocompatible and bioactive. CLINICAL RELEVANCE: The tested new tricalcium silicate cement confirms its suitability as an alternative to MTA in vital pulp therapy.

Consensus report of the European Federation of Conservative Dentistry: erosive tooth wear--diagnosis and management.

OBJECTIVE: Due to an increased focus on erosive tooth wear (ETW), the European Federation of Conservative Dentistry (EFCD) considered ETW as a relevant topic for generating this consensus report. MATERIALS AND METHODS: This report is based on a compilation of the scientific literature, an expert conference, and the approval by the General Assembly of EFCD. RESULTS: ETW is a chemical-mechanical process resulting in a cumulative loss of hard dental tissue not caused by bacteria, and it is characterized by loss of the natural surface morphology and contour of the teeth. A suitable index for classification of ETW is the basic erosive wear examination (BEWE). Regarding the etiology, patient-related factors include the pre-disposition to erosion, reflux, vomiting, drinking and eating habits, as well as medications and dietary supplements. Nutritional factors relate to the composition of foods and beverages, e.g., with low pH and high buffer capacity (major risk factors), and calcium concentration (major protective factor). Occupational factors are exposition of workers to acidic liquids or vapors. Preventive management of ETW aims at reducing or stopping the progression of the lesions. Restorative management aims at reducing symptoms of pain and dentine hypersensitivity, or to restore esthetic and function, but it should only be used in conjunction with preventive strategies. CONCLUSIONS: Effective management of ETW includes screening for early signs of ETW and evaluating all etiological factors. CLINICAL RELEVANCE: ETW is a clinical condition, which calls for the increased attention of the dental community and is a challenge for the cooperation with other medical specialities.

Individual growth detection of bacterial species in an in vitro oral polymicrobial biofilm model.

Most in vitro studies on the antibacterial effects of antiseptics have used planktonic bacteria in monocultures. However, this study design does not reflect the in vivo situation in oral cavities harboring different bacterial species that live in symbiotic relationships in biofilms. The aim of this study was to establish a simple in vitro polymicrobial model consisting of only three bacterial strains of different phases of oral biofilm formation to simulate in vivo oral conditions. Therefore, we studied the biofilm formation of Actinomyces naeslundii (An), Fusobacterium nucleatum (Fn), and Enterococcus faecalis (Ef) on 96-well tissue culture plates under static anaerobic conditions using artificial saliva according to the method established by Pratten et al. that was supplemented with 1 g l(-1) sucrose. Growth was separately determined for each bacterial strain after incubation periods of up to 72 h by means of quantitative real-time polymerase chain reaction and live/dead staining. Presence of an extracellular polymeric substance (EPS) was visualized by Concanavalin A staining. Increasing incubation times of up to 72 h showed adhesion and propagation of the bacterial strains with artificial saliva formulation. An and Ef had significantly higher growth rates than Fn. Live/dead staining showed a median of 49.9 % (range 46.0-53.0 %) of living bacteria after 72 h of incubation, and 3D fluorescence microscopy showed a three-dimensional structure containing EPS. An in vitro oral polymicrobial biofilm model was established to better simulate oral conditions and had the advantage of providing the well-controlled experimental conditions of in vitro testing.

In vitro optical detection of simulated blood pulse in a human tooth pulp model.

OBJECTIVE: Noninvasive optical methods such as photoplethysmography, established for blood pulse detection in organs, have been proposed for vitality testing of human dental pulp. However, no information is available on the mechanism of action in a closed pulp chamber and on the impairing influence of other than pulpal blood flow sources. Therefore, the aim of the present in vitro study was to develop a device for the optical detection of pulpal blood pulse and to investigate the influence of different parameters (including gingival blood flow [GBF] simulation) on the derived signals. MATERIALS AND METHODS: Air, Millipore water, human erythrocyte suspensions (HES), non-particulate hemoglobin suspension (NPHS), and lysed hemoglobin suspension (LHES) were pulsed through a flexible (silicone) or a rigid (glass) tube placed within an extracted human molar in a tooth-gingiva model. HES was additionally pulsed through a rigid tube around the tooth, simulating GBF alone or combined with the flow through the tooth by two separate peristaltic pumps. Light from high-power light-emitting diodes (625 nm (red) and 940 nm (infrared [IR]); Golden Dragon, Osram, Germany) was introduced to the coronal/buccal part of the tooth, and the signal amplitude [∆U, in volts] of transmitted light was detected by a sensor at the opposite side of the tooth. Signal processing was carried out by means of a newly developed blood pulse detector. Finally, experiments were repeated with the application of rubber dam (blue, purple, pink, and black), aluminum foil, and black antistatic plastic foil. Nonparametric statistical analysis was applied (n = 5; α = 0.05). RESULTS: Signals were obtained for HES and LHES, but not with air, Millipore water, or NPHS. Using a flexible tube, signals for HES were higher for IR compared to red light, whereas for the rigid tube, the signals were significantly higher for red light than for IR. In general, significantly less signal amplitude was recorded for HES with the rigid glass tube than with the flexible tube, but it was still enough to be detected. ∆U from gingiva compared to tooth was significantly lower for red light and higher for IR. Shielding the gingiva was effective for 940 nm light and negligible for 625 nm light. CONCLUSIONS: Pulpal blood pulse can be optically detected in a rigid environment such as a pulp chamber, but GBF may interfere with the signal and the shielding effect of the rubber dam depends on the light wavelength used. CLINICAL RELEVANCE: The optically based recording of blood pulse may be a suitable method for pulp vitality testing, if improvements in the differentiation between different sources of blood pulse are possible.

Establishment of an optimized ex vivo system for artificial root canal infection evaluated by use of sodium hypochlorite and the photodynamic therapy.

AIM: To establish a refined model of artificially infected root canals and confirm its suitability as a sensitive ex vivo method to assess the efficacy of disinfecting agents. Disinfection was evaluated using sodium hypochlorite (NaOCl), either blocked or unblocked by sodium thiosulphate, and a recently promoted method of disinfection, the antibacterial photodynamic therapy (PDT). METHODOLOGY: The roots of bovine incisors were sectioned into three parts, the canals of coronal and middle regions were filled with a suspension of Enterococcus faecalis and the apical region with culture medium. After 7 days, coronal sections were disinfected using NaOCl (0.5%, 1.0% and 3.0% for 30, 60 and 600 s) or a system for photoactivated chemotherapy (PACT; Cumdente, Tübingen, Germany) for antibacterial PDT. Apical sections served as sterile controls and middle sections as bacterial growth controls. In half of the NaOCl-treated specimens, disinfection was arrested. Dentine chips from biopsies at different depths from the central canal towards the periphery were plated and assessed for colony-forming units (CFU). Disinfection was considered biologically relevant if the reduction of CFU was at least three log10 orders of magnitude. RESULTS: Colony-forming units of 10³ - 104 in growth controls indicated effective artificial infection. A biologically relevant reduction of CFU was accomplished with unblocked NaOCl, but not after blocking with NaOCl nor with PDT. CONCLUSIONS: The system reliably detected disinfection of the root canal and dentinal tubules and proved suitable for ex vivo testing of root canal disinfection. The effect of NaOCl depended on the duration of impact. Under the present experimental conditions, the antibacterial PDT system did not achieve sufficient disinfection.

The challenge for innovation in direct restorative materials.

During the past 50 years, a series of key UN conferences have established a framework to minimize human health risks from environmental exposures to key chemicals. In January 2013, more than 140 countries agreed to the text of new treaty to minimize Hg effects on the environment (the Minamata Convention). Dental caries is omnipresent around the globe, affecting 60% to 90% of school children and most adults, and producing discomfort that affects quality of life. Dental amalgam is frequently used to treat carious lesions and its use releases mercury into the environment. The best way to avoid the use of dental amalgam is to emphasize caries prevention. Alternatives to amalgam are suitable in some applications, but no replacement for amalgam has been found for large posterior restorations. For any restorative material, safety and environmental impacts are part of clinical risk assessment. Safety is freedom from unacceptable risks. Risk is a combination of probability of exposure and severity of harm. Best management practices are crucial to manage dental amalgam, but these impose additional that are disproportionately more for developing countries. The Minamata Convention seeks a phase-out of all mercury-based products except dental amalgam, where a phase-down is the present goal. For dentistry, the most important focus is the promotion of caries prevention and research on new materials.