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Introduction: The presently used impulse echo ultrasound examination is not suitable to provide relevant and reliable information about the jawbone, because ultrasound (US) almost completely reflects from the hard cortical jawbone. At the same time, “focal osteoporotic bone marrow defects” (BoneMarrowDefects = BMD) in jawbone are the subject of scientific presentations and discussions.

Purpose: Can a newly developed trans-alveolar ultrasonic sonography (TAU-n) device locate and ascertain BMD?

Patients and methods: TAU-n consists of a two-part handpiece with an extraoral ultrasound transmitter and an intraoral ultrasound receiver. The TAU-n computer display shows the different jawbone densities with corresponding colour coding. The changes in jawbone density are also displayed numerically. The validation of TAU-n readings: A usual orthopantomogram (2D-OPG) on its own is not suitable for unequivocally determining jawbone density and has to be excluded from this validation. For validation, a 3D-digital volume tomogram@/cone beam computer tomogram (DVT@/CBCT) with the capacity to measure Hounsfield units (HU) and a TAU-n are used to determine the presence of preoperative BMD in 82 patient cases. Postoperatively, histology samples and multiplex analysis of RANTES@/CCL5 (R@/C) expression derived from surgically cleaned BMD areas are evaluated.

Results: In all 82 bone samples, DVT-HU, TAU-n values and R/C expressions show the presence of BMD with chronic inflammatory character. However, five histology samples showed no evidence of BMD. All four evaluation criteria (DVT-HU, TAU-n, R/C, histology) confirm the presence of BMD in each of the 82 samples.

Conclusion: The TAU-n method almost completely matches the diagnostic reliability of the other methods. The newly developed TAU-n scanner is a reliable and radiation-free option to detect BMD.

For more than 25 years, I have been, as a gastroenterologist, interested in inflammatory bowel disease—Crohn’s disease and ulcerative colitis—and the gut-brain connection, particularly in childhood autism. In addition, I am concerned with the environmental factors that are driving the current epidemics of both autism and inflammatory bowel disease. The issue is contentious, and one’s view depends greatly on perspective. This article provides one perspective on the delicate and often misunderstood ecological balance between man and microbe, a misunderstanding fraught with assumptions and wishful thinking.

Temporomandibular disorders (TMD) are a common stomatognathic disease affecting all age groups. Patients with internal derangement (ID) or osteoarthritis (OA) of temporomandibular joint (TMJ) often have TMJ synovitis. When TMJ synovial membrane is damaged, many inflammatory cytokines are produced and secreted from TMJ synoviocytes to synovial fluid of TMJ. It has been widely reported that many kinds of biologic factors are produced from TMJ synoviocytes stimulated with interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha. One of the major symptoms of TMD is pain of the TMJ. Many study groups have studied relations between the development of TMJ pain and biologic factors secreted into synovial fluid of TMJ. Here, we summarize previous reports trying to elucidate this correlation. On the other hand, it has been reported that a new molecular mechanism of IL-1beta secretion called inflammasome is involved in several diseases with sterile inflammation. Because TMJ synovitis with ID and OA of TMJ is also sterile inflammation, inflammasome may be involved in the development of TMJ synovial inflammation. This review describes some molecular mechanisms underlying inflammation in TMJ, especially in TMJ synovitis, which may be useful for the development of new therapies against TMD.

This paper reports on the conclusions of two workshops held in Copenhagen in September 2017 and November 2018 focused on medication-related osteonecrosis of the jaws (MRONJ). The workshops were organized and attended by a European task force on MRONJ, i.e. a multidisciplinary group of European clinical investigators with a special interest in the diagnosis and management of MRONJ and a track record of relevant research and publications. The aim of the workshops were to (i) highlight some of the most controversial aspects of current knowledge on MRONJ, including definition and classification, risk factors and management, and (ii) provide an expert opinion-based consensus with a view to inform clinicians and advise researchers, as a first step of reaching solutions. It should be pointed out that all results and comments presented are the authors (the workshop group members) personal views and the present form of this publication is based on genuine consensus of all authors

Prevention of dental caries (tooth decay), one of the most common chronic diseases globally,1 requires the global implementation of WHO’s guideline on sugars intake.2,3 WHO recommends that individuals consume less than 10% of total energy intake from free sugars and that intake below 5% would be beneficial.3 The global dental research community, as the Lancet oral health Series1,2argues, has an important role in the implementation
of the WHO guideline by promoting research on public health and dietary interventions, among other actions. However, dental research activities have not focused on sugars for many years. To remedy this, the European Organisation for Caries Research (ORCA) and the European Association of Dental Public Health (EADPH) organised a joint symposium on sugars in 2015 to stimulate new research.4 The same year, the American Dental Association urged the US National Institute of Dental and Craniofacial Research (NIDCR) to increase research on sugars and oral health.5

Background: Rheumatoid arthritis (RA) and periodontal disease are inter-related conditions. However, factors predictive of periodontal disease progression in patients with early rheumatoid arthritis (eRA) are lacking. The aim of this study was to identify factors associated with the progression of clinical attachment loss (CAL) in interproximal dental sites of eRA patients.

Methods: Twenty-eight eRA patients were evaluated for the progression of CAL at 280 interproximal dental sites at 1 year of follow-up. Markers of RA activity (rheumatoid factor, erythrocyte sedimentation rate, and C-reactive protein), a marker of bone resorption (Dickkopf-related protein 1), Disease Activity Score 28 and Simple Disease Activity Index were included as potential systemic predictive factors. Plaque index, gingival index, pocket depth, clinical attachment level and Dickkopf-related protein 1 in crevicular fluid at baseline were included as potential local predictive factors. Data were analysed in a hierarchical structure using generalised linear mixed models for progression at each site (> 2 mm) during follow-up.

Results: C-reactive protein level was the most important predictive systemic factor for the progression of CAL. The mean CAL and a high degree of gingival inflammation in interproximal sites at baseline were important predictive local factors (p < 0.0001). Patients who received combined treatment with disease-modifying antirheumatic drugs and corticosteroids exhibited less CAL (p < 0.0001). The predictive value of the generalised linear mixed model for progression was 85%.

Conclusions: Systemic factors, including RA disease activity and baseline periodontal condition, were associated with periodontal progression. Pharmacological treatment may affect periodontal progression in patients with early RA.

BACKGROUND:

Concentrated growth factor (CGF), as a natural biomaterial, is known to contain platelets, cytokines, and growth factors to facilitate the healing process, but there has been little information acquired in regenerative endodontics. The purpose of this study was to investigate the effects of CGF on proliferation, migration, and differentiation in human dental stem pulp cells (hDPSCs) exposed to lipopolysaccharide (LPS) in vitro and its potential role in pulp regeneration of the immature teeth in vivo.

METHODS:

In vitro experiments: CGF-conditioned medium were extracted by freeze-dried method. hDPSCs were isolated and identified. The proliferative potential of hDPSCs with different concentration of CGF and LPS was evaluated by Cell Counting Kit-8. Migration capacity was analyzed by Transwell assays, odonto/osteoblastic differentiation was determined by measuring alkaline phosphatase (ALP) activity using ALP staining, and the extent of mineralization was evaluated by using Alizarin red S staining. The mRNA expression level of DMP-1, DSPP, OPN, Runx2, and OCN were determined by quantitative polymerase chain reaction (qPCR). In vivo experiments: CGF were used as root canal filling agent of the immature single-rooted teeth in the beagle dogs. The teeth were then radiographed, extracted, fixed, demineralized, and subjected to histologic analyses at 8 weeks. The newly formed dentine-pulp complex and the development of apical foramen were evaluated by the hematoxylin-eosin (HE) and Masson trichrome technique. Soft tissues were analyzed by immunohistochemical staining of vascular endothelial growth factor (VEGF) and Nestin.

RESULTS:

In vitro experiments: The cultured cells exhibited the characteristics of mesenchymal stem cell. The treatment of LPS significantly increased the expression of TNF-α, IL-1β, IL-6, and IL-8 in hDPSCs, and CGF inhibited the mRNA expression of IL-8 in LPS-stimulated hDPSCs. The proliferation values of the CGF group in LPS-stimulated hDPSCs were significantly higher than that of the control group from day 3 to day 7 (P < 0.05). In addition, the number of migratory cells of the CGF group was greater than that of the control group at 24 h with or without LPS treatment. ALP activities increased gradually in both groups from day 4 to day 7. The mineralized nodules and the expression of odontogenesis-related genes DMP-1 and DSPP, osteogenesis-related genes OPN, Runx2, and OCN were dramatically enhanced by CGF in LPS-stimulated hDPSCs at days 21 and 28. In vivo experiments: In CGF treated group, the results of radiograph, HE, and Masson trichrome staining showed a continuing developed tooth of the immature teeth in the beagle dogs (i.e., the ingrowth of soft tissues into the root canal, the thickened internal root dentin walls, and the closed apex), which resembled the normal tooth development in the positive control group. The immunohistochemical staining showed that VEGF and Nestin were both moderately expressed in the regenerated pulp-like tissues which indicating the vascularization and innervation.

CONCLUSIONS:

CGF has a positive effect on the proliferation, migration, and differentiation of hDPSCs exposed to LPS in vitro, and it can also promote the regeneration of dentine-pulp complex of the immature teeth in the beagle dogs in vivo. Therefore, CGF could be a promising alternative biomaterial in regenerative endodontics.

Background: Although several studies assessed the effect of bisphosphonate (BIS) administration on alveolar bone loss, this relationship has not been fully investigated using longitudinal analysis. The aim of the this article is to predict annual alveolar bone loss in a subpopulation of older adults patients who were taking oral bisphosphonate (BIS), adjusting for systemic diseases and associated risk factors.

Methods: This is a retrospective cohort study. We identified all subjects who reported receiving oral bisphosphonate from 2008 to 2015 (N = 30) using the electronic health records of each patient to identify suitable radiographs for analysis. For the longitudinal data analysis, 26 subjects were eligible for inclusion, having at least two exposures of the complete mouth set or repeated bitewing radiographs at least a one-year interval; they were then matched on age and sex to another 26 patients who did not report receiving bisphosphonate at any point of their life.

Results: Mild periodontitis was higher in the BIS group compared to the no BIS group; however, moderate periodontitis was higher in the no BIS group. For those who did not take oral BIS, change over time was not significant after the two-year period. However, the BIS group had experienced 0.088 mm more bone loss compared to the no BIS group (95% CI: 0.001, 0.176. P-value = 0.048), adjusting for all other variables included in the model.

Conclusion: The group that reported receiving oral bisphosphonates showed no improvement in maintaining alveolar bone level, and the use of oral BIS may not be effective in reducing annual alveolar bone loss; however, emerging evidence is promising for the use of bisphosphonate as an adjunctive local delivery medication for the management of periodontal diseases.

OBJECTIVES:

The purpose of this in vitro study was by using quantitative real-time PCR and culturing to determine the effectiveness of two irrigation and cleaning systems in removing multispecies oral biofilms from root canals.

MATERIAL AND METHODS:

Twenty extracted human molars were instrumented to size #15/.02 and then cleaned with the GentleWave (GW) System. The teeth were autoclaved to provide the same sterile baseline. The molars were filled with mixed plaque suspended in BHI and centrifuged to inoculate the biofilms. After 2 weeks of incubation, the teeth were randomly divided into two treatment groups. In GW group (26 canals), the teeth were further instrumented to size #15/04, and in PiezoFlow (PF) group (30 canals) to #35/.04. The teeth were then cleaned either with GW System or ProUltra PiezoFlow Active Ultrasonic System using 3% sodium hypochlorite NaOCl, 8% EDTA, and sterile water as irrigants. Samples (S1, S2, and S3) for bacterial cultures were taken from 13 canals before and after instrumentation and after final cleaning. Quantitative real-time PCR was performed from all 56 canals, and universal bacterial, one genus, and one species-specific primers were used to determine the presence of microorganisms in samples from root canals before and after instrumentation and after final cleaning. Statistical analyses were performed using the Mann-Whitney U test with the significance level set at P < 0.05.

RESULTS:

Bacterial culturing from the canal samples revealed strong reduction of bacteria from S1 to S2 in both groups after instrumentation and irrigation with water only. No growth was detected in any of the S3 samples after cleaning in either group. A highly significant reduction in bacterial DNA was recorded by qPCR for both groups (P < 0.001). GW System showed more constant and a significantly higher reduction of total microbial DNA (P = 0.007), Enterococcus faecalis DNA (P = 0.011) and Streptococcus spp. DNA (P = 0.029) than the Ultrasonic System. The amount of residual microbial DNA calculated as an average of residual DNA in each individual canal in PF group was 1.99% and in GW group 0.09%.

CONCLUSIONS:

While both systems demonstrated a highly effective reduction of intracanal bacterial DNA, the final total amount and variation in the number of residual bacterial DNA was significantly smaller in the GW group.

CLINICAL RELEVANCE:

Elimination of microbes from the infected root canal system is regarded as the key for long-term clinical success. While both GentleWave and Ultrasonic Systems used with NaOCl and EDTA demonstrated a highly effective reduction of intracanal bacterial DNA; GW produced higher reduction and better predictability.

Dendritic cells are an important link between innate and adaptive immune response. The role of dendritic cells in bone homeostasis, however, is not understood. Osteoporosis medications that inhibit osteoclasts have been associated with osteonecrosis, a condition limited to the jawbone, thus called medication-related osteonecrosis of the jaw. We propose that disruption of the local immune response renders the oral microenvironment conducive to osteonecrosis. We tested whether zoledronate (Zol) treatment impaired dendritic cell (DC) functions and increased bacterial load in alveolar bone in vivo and whether DC inhibition alone predisposed the animals to osteonecrosis. We also analyzed the role of Zol in impairment of differentiation and function of migratory and tissue-resident DCs, promoting disruption of T-cell activation in vitro. Results demonstrated a Zol induced impairment in DC functions and an increased bacterial load in the oral cavity. DC-deficient mice were predisposed to osteonecrosis following dental extraction. Zol treatment of DCs in vitro caused an impairment in immune functions including differentiation, maturation, migration, antigen presentation, and T-cell activation. We conclude that the mechanism of Zol-induced osteonecrosis of the jaw involves disruption of DC immune functions required to clear bacterial infection and activate T cell effector response.