Fibulin-2 is an extracellular matrix inhibitor of oligodendrocytes relevant to multiple sclerosis.

Impairment of oligodendrocytes and myelin contributes to neurological disorders including multiple sclerosis (MS), stroke, and Alzheimer's disease. Regeneration of myelin (remyelination) decreases the vulnerability of demyelinated axons, but this repair process commonly fails with disease progression. A contributor to inefficient remyelination is the altered extracellular matrix (ECM) in lesions, which remains to be better defined. We have identified fibulin-2 (FBLN2) as a highly upregulated ECM component in lesions of MS and stroke and in proteome databases of Alzheimer's disease and traumatic brain injury. Focusing on MS, the inhibitory role of FBLN2 was suggested in the experimental autoimmune encephalomyelitis (EAE) model, in which genetic FBLN2 deficiency improved behavioral recovery by promoting the maturation of oligodendrocytes and enhancing remyelination. Mechanistically, when oligodendrocyte progenitors were cultured in differentiation medium, FBLN2 impeded their maturation into oligodendrocytes by engaging the Notch pathway, leading to cell death. Adeno-associated virus deletion of FBLN2 in astrocytes improved oligodendrocyte numbers and functional recovery in EAE and generated new myelin profiles after lysolecithin-induced demyelination. Collectively, our findings implicate FBLN2 as a hitherto unrecognized injury-elevated ECM, and a therapeutic target, that impairs oligodendrocyte maturation and myelin repair.

Impact of fully guided implant planning software training on the knowledge acquisition and satisfaction of dental undergraduate students.

BACKGROUND: A majority of dental school students do not undergo hands-on clinical training in implantology in the undergraduate curriculum. Training is usually restricted to pre-implant evaluation and post-implant prostheses. Virtual implant planning software (VIPS) provides an alternative opportunity for undergraduate students to experience implant planning much before gaining hands-on experience. However, not many studies have the contribution of VIPS to the knowledge acquisition of students. We conducted a preliminary study to evaluate the knowledge acquisition of the students when exposed to a hands-on session of VIPS. We also evaluated students' satisfaction levels, when exposed to hands-on training in fully guided implant planning software. METHODS: A two-part theory lecture on fully guided implant planning was delivered to 90, 5th (final)-year dental undergraduate students by the oral radiology faculty. The students were then randomly divided into three groups. Group A was exposed to didactic lectures only. Group B was shown a video for fully guided implant planning in addition to the didactic lecture. Group C was shown a video for fully guided implant planning in addition to a didactic lecture and then performed a hands-on session of virtual implant planning under faculty guidance. Students from all groups were given an MCQ-based test. After the completion of the test students from group A and B also received VIPS hands-on training. Students from all three groups answered and a feedback questionnaire regarding their satisfaction levels with VIPS. RESULTS: The overall test score of students in Group C was higher than their colleagues in both Groups A and B and the differences were statistically significant (p = 0.01). More than 85% of the students were satisfied with the teaching approach. CONCLUSIONS: The utilization of VIPS in the training of dental undergraduate students improves their performance confirming better knowledge acquisition and content mastery.

The Effect of Nanosilver Sodium Fluoride on the Mechanical and Physiochemical Properties of Artificially Demineralised Dentin.

PURPOSE: To synthesise and characterise nanosilver sodium fluoride (NSSF) and assess the effect of applying this formulation in vitro on artificially demineralised root dentin lesions, compared with the application of silver diamine fluoride (SDF), sodium fluoride (NAF) or no treatment, in terms of mechanical, chemical and ultrastructural properties. MATERIALS AND METHODS: NSSF was prepared using 0.5 wt% chitosan solution. On 40 extracted human molars, the buccal aspect of the cervical thirds of roots were prepared and divided into 4 groups of 10 each: control (no treatment), NSSF, SDF and NaF (n = 10). The specimens were examined using scanning electron microscopy (SEM), atomic force microscopy (AFM), and x-ray photoelectron spectroscopy (XPS). Fourier transform infrared spectroscopy (FTIR), surface and cross-sectional microhardness and nano-indentation tests were performed to determine the mineral and carbonate content, microhardness, and nanohardness, respectively. Statistical analysis was performed to determine the differences between the different treatment groups for the set parameters using parametric and non-parametric tests. Tukey's and Dunnet's T3 post-hoc tests were further used for multiple comparisons between groups (α = 0.05). RESULTS: The control group (no treatment) was found to have statistically significantly lower mean scores for surface and cross-sectional microhardness compared with all other test groups (NaF, NSSF and SDF) (p < 0.05). Spearman's rank correlation test showed statistically insignificant differences between the mineral-to-matrix ratio (M:M) and carbonate content of all groups (p < 0.05). CONCLUSIONS: Treatment of root lesions with NSSF yielded comparable results to SDF and NaF under in-vitro conditions.

Acceptability of fully guided virtual implant planning software among dental undergraduate students.

BACKGROUND: Fully guided implant surgery as a technique is gaining popularity. It has been observed that use of surgical guides improves precision and predictability for dental implant placement. However, like any other newer technology, the acceptance of fully guided dental implant technology among users is based upon its perceived usability. This study aimed at evaluating the perception about using Virtual Implant Planning Software (VIPS) among undergraduate dental students at the university of Sharjah. METHODS: Ninety-Six dental surgery students from the University of Sharjah were included in the study. One week after the Virtual Implant Planning Software (Planmeca Romexis version 6.2 procedure, students were asked to complete a Combined technology acceptance model and the theory of planned behaviour (C-TAM TPB) questionnaire. Sixty-six students responded to the questionnaire. RESULTS: Cronbach's alpha surpassed 0.7 for perceived usefulness, perceived ease of use, perceived behavioral control, and subjective norm. Attitude and behavioural intention reported Cronbach's alpha values less than 0.7. Spearman's correlation coefficient was significant for all the constructs. Perceived ease of use explained 49%, 33%, and 42% of the variance of perceived usefulness (R2 = 0.49), attitude (R2 = 0.33), and perceived behavioral control (R2 = 0.42) respectively. Perceived usefulness explained 25%, 18%, and 23% of the variance of attitude (R2 = 0.25), behavioral intention (R2 = 0.18), and perceived behavioral control (R2 = 0.23) respectively. Attitude accounted for 25%, 33%, and 29% of the variance of behavioral intention (R2 = 0.25), perceived behavioral control (R = 0.33), and subjective norm (R = 0.29) respectively. CONCLUSION: The fully guided VIPS was acceptable by dental students specifically because of its usability. This makes VIPS a very effective tool for teaching implantology for dental students. VIPS also allows students to perform multiple repetitions of the implant planning procedure which enhances understanding and content retention.

Enhancing axonal myelination in seniors: A review exploring the potential impact cannabis has on myelination in the aged brain.

Consumption of cannabis is on the rise as public opinion trends toward acceptance and its consequent legalization. Specifically, the senior population is one of the demographics increasing their use of cannabis the fastest, but research aimed at understanding cannabis' impact on the aged brain is still scarce. Aging is characterized by many brain changes that slowly alter cognitive ability. One process that is greatly impacted during aging is axonal myelination. The slow degradation and loss of myelin (i.e., demyelination) in the brain with age has been shown to associate with cognitive decline and, furthermore, is a common characteristic of numerous neurological diseases experienced in aging. It is currently not known what causes this age-dependent degradation, but it is likely due to numerous confounding factors (i.e., heightened inflammation, reduced blood flow, cellular senescence) that impact the many cells responsible for maintaining overall homeostasis and myelin integrity. Importantly, animal studies using non-human primates and rodents have also revealed demyelination with age, providing a reliable model for researchers to try and understand the cellular mechanisms at play. In rodents, cannabis was recently shown to modulate the myelination process. Furthermore, studies looking at the direct modulatory impact cannabis has on microglia, astrocytes and oligodendrocyte lineage cells hint at potential mechanisms to prevent some of the more damaging activities performed by these cells that contribute to demyelination in aging. However, research focusing on how cannabis impacts myelination in the aged brain is lacking. Therefore, this review will explore the evidence thus far accumulated to show how cannabis impacts myelination and will extrapolate what this knowledge may mean for the aged brain.

The Outcomes of Maternal Immune Activation Induced with the Viral Mimetic Poly I:C on Microglia in Exposed Rodent Offspring.

Maternal immune activation (MIA) can result from a variety of maternal inflammatory factors, including metabolic disorders, nutritional deficits, infections, and psychosocial stress. MIA has been consistently recognized as a major risk factor for neurodevelopmental disorders, and this association seems to be especially important for viral infections as viral exposure during pregnancy was associated with a higher risk of developing neurodevelopmental disorders, such as schizophrenia. In MIA, the gestational parent's inflammatory response to an immune stimulus alters or interrupts fetal development, triggering neurodevelopmental consequences. As MIA can occur in any pregnancy, it is important to understand the many factors at play that contribute to altered brain development in the offspring, especially considering recent global events such as the COVID-19 pandemic. The underlying mechanisms by which MIA results in deleterious outcomes are not yet clear, but due to the inflammatory response it initiates, it is becoming apparent that microglia are critically involved. Through investigation of MIA animal models, the role of microglia in this field is becoming more evident. Compelling evidence from animal models indicates that MIA can disrupt synaptic pruning, neuronal progenitor cell proliferation/differentiation, oligodendrogenesis, and more. Microglia appear as an active player, assisting these neural-related functions during healthy development but also mediating MIA-induced disturbances in these critical processes when neurodevelopment is challenged. The present review illustrates this complex web by reviewing recent literature, focusing on the outcomes of MIA resulting from viral mimetic polyinosinic-polycytidylic acid in rodents, to provide a clear description of how MIA impacts microglial functions and what this means for the offspring's neurodevelopment. Moreover, we discuss the possible implications of the COVID-19 pandemic on the neurodevelopment of the current and next generations in the frame of MIA models and propose some putative pharmacological and non-pharmacological approaches to prevent or attenuate MIA consequences.

Double Crown-Retained Removable Prostheses Supported by Implants or Teeth and Implants: A Long-Term Clinical Retrospective Evaluation.

OBJECTIVES: The objective of this retrospective clinical study was to investigate the survival rates and complications of implant (I)-retained or tooth-implant (TI)-retained prostheses and abutments (teeth, implants) over a mean observation period of 11.26 years. The study also aimed to analyze the differences and complication rates between implant-retained double crown removable dental prostheses (I-DC-RDPs) versus tooth-implant-retained double crown removable dental prostheses (TI-DC-RDPs). MATERIAL AND METHODS: We reviewed the clinical data of 110 nonsmokers (mean age = 53.9 years) who received DC-RDPs in maxillary or mandibular arches. 153 teeth and 508 implants were used to restore partially edentulous (PE; TI-DC-RDPs; n = 53) and completely edentulous (CE; TI-DC-RDPs; n = 57) arches. Two designs of the distal extension were used: cantilevers (CANs) and saddles (SADs). Restorations were examined for abutment survival, mechanical, or biological complications. RESULTS: The 10-year survival rates were 99.3% (95% CI: 95.4-99.9%) for teeth and 99.3% (95% CI: 97.5-99.7%) for implants. The cumulative rates of TI- and I-RDPs free of technical complications were 77% and 86%, respectively. The risk of complications was not significantly different between the CAN and SAD subgroups of I-RDPs (p > 0.05). However, for TI-RDPs, technical complication risk was significantly higher in SAD type compared with CAN restorations (p = 0.02). CONCLUSIONS: I- and TI-DC-RDPs seem to be recommendable for restoration of CE or PE arches. The technical and biological complication rates were lower for I-DC-RDPs in the CE arches than for TI-DC-RDPs in the PE arches. Regarding the RDP design, CAN prostheses produced significantly fewer technical complications than did SAD prostheses.

Differences in Mechanical and Physicochemical Properties of Several PTFE Membranes Used in Guided Bone Regeneration.

Non-resorbable PTFE membranes are frequently used in dental-guided bone regeneration (GBR). However, there is a lack of detailed comparative studies that define variations among commonly used PTFE membranes in daily dental clinical practice. The aim of this study was to examine differences in physicochemical and mechanical properties of several recent commercial PTFE membranes for dental GBR (CytoplastTM TXT-200, permamem®, NeoGen®, Surgitime, OsseoGuard®-TXT, OsseoGuard®-NTXT). Such differences have been rarely recorded so far, which might be a reason for the varied clinical results. For that reason, we analyzed their surface architecture, chemical composition, tensile strength, Young's modulus, wettability, roughness, density, thickness and porosity. SEM revealed different microarchitectures among the non-textured membranes; the textured ones had hexagonal indentations and XPS indicated an identical spectral portfolio in all membranes. NeoGen® was determined to be the strongest and OsseoGuard®-TXT was the most elastic. Wettability and roughness were highest for Surgitime but lowest for OsseoGuard®-NTXT. Furthermore, permamem® was the thinnest and NeoGen® was identified as the thickest investigated GBR membrane. The defect volumes and defect volume ratio (%) varied significantly, indicating that permamem® had the least imperfect structure, followed by NeoGen® and then Cytoplast TM TXT-200. These differences may potentially affect the clinical outcomes of dental GBR procedures.

Impact of Guidance and Multitasking on Manual Dexterity Skills in Dentistry.

OBJECTIVES: This study investigated the effect of learning by observation on the development of fine motor skills related to endodontic manual instrumentation. We evaluated if learning by observation with guidance had any influence upon operator performance under tense or taxing conditions. MATERIALS AND METHODS: Dental students prepared standardized simulated root canals of varying morphology. Learning involved silent video with hand guidance (n = 23), audiovisual combined with oral instructions (n = 23), or silent video (n = 13). Undergraduates who previously completed conventional preclinical endodontics provided comparative data as a control group (n = 16). During investigations, a root canal of a lower molar plastic tooth was shaped, beginning with a primary task, and followed by multitasking conditions. The performance of the students was assessed by evaluating the accuracy of dental canal shaping and time taken to complete the task. STATISTICAL ANALYSIS: Differences were analyzed using ANOVA (p < 0.05). RESULTS: Performance was similar during learning between the three experimental groups. Accuracy of the performance did not differ within each group for the two tests nor between the groups at each test (p > 0.05). CONCLUSIONS: These findings demonstrated that performance subsequent to learning by observation without instructions was comparable to learning with instructed observation. The results also identified that the performance of the experimental group (1.5- to 2-hour practice) was comparable with the conventional control group (15- to 20-hour practice). Alternative approaches to learning dexterity skills in dentistry may provide improved outcomes, especially in demanding situations.

Ground Validation Reveals Limited Applicability of Species Distribution Models for Dakota Skipper (Hesperia dacotae, Lepidoptera: Hesperiidae) Recovery Efforts in Canada.

Species distribution models (SDMs) use spatial relationships between species occurrence and habitat (predictor) variables to generate maps of habitat suitability across a region of interest. These maps are frequently used in recovery planning efforts for endangered species, but they are influenced by data availability, selection of predictor variables, and choice of model type. Ground validation is necessary to robustly evaluate map accuracy, but it is rarely done, making it difficult to determine which modeling approach is best-suited for a given species or region. To address this uncertainty, we used two SDM types (Maxent and GLM) and two methods of selecting predictor variables to build four SDMs for an endangered prairie butterfly (Dakota skipper, Hesperia dacotae) in two regions of Manitoba, Canada. We then conducted field-based habitat suitability assessments at 120 locations in each region to enable direct comparisons of model output and accuracy. We found that soil type and surrounding landcover (grassland versus cropland) were important predictors of species occurrence regardless of region, predictor selection method, or model type. Cross-validation statistics indicated that most SDMs performed well (AUC > 0.7), but ground validation revealed that the habitat suitability maps they generated were inaccurate (Cohen's kappa < 0.4). Maxent models produced more accurate maps than GLMs, likely because false species absences adversely affected the latter, but only one Maxent-based map was accurate enough to help locate sites for future field investigations (Cohen's kappa > 0.3). Our results emphasize the importance of ground-validating SDM-based habitat suitability maps before incorporating them into species recovery plans.

Peri-Implant Mucosa Augmentation with an Acellular Collagen Matrix.

Peri-implant keratinized mucosa (PI-KM) may support implant survival. Acellular collagen matrices (aCMs) have been widely used to facilitate soft tissue regeneration. The aim of this study was to investigate clinical outcomes obtained with the use of an aCM (mucoderm®) to enhance PI-KM. In this retrospective non-randomized case series, 27 restored implants in 14 patients (eight males and six females, mean age = 56 years) with a PI-KM width ≤ 1 mm were followed for 6 months. It was demonstrated that aCM grafts augmented PI-KM effectively (mean increase of 5.4 mm; >533%) without a significant change in bleeding on probing (BOP) from baseline. The mean aCM shrinkage was 3.9 mm (42%). Gender, area, arch, and BOP did not influence PI-KM augmentation or aCM shrinkage significantly. The present results demonstrated that the examined aCM was effective and predictable for attaining a band of keratinized tissue, while avoiding graft donor site harversting.

Tooth-implant connection with fixed partial dentures in partially edentulous arches. A retrospective cohort study over an 11.8 year observation period.

BACKGROUND: The fixed tooth-implant connection remains a controversial issue. This private practice-based retrospective study aimed to evaluate the clinical outcomes of a contemporary fixed partial denture (FPD) design for connecting natural teeth and implants (TI-FPD), over an 11.8 years observation period. MATERIAL AND METHODS: The data of 91 partially edentulous patients (44 males and 47 females, mean age of 47.7 years) treated with a newly designed TI-FPD retained on 1 implant and 1 natural tooth were analyzed retrospectively. Teeth were covered with electroformed copings and a CAD/CAM made bridge was fixed over the abutments with provisional cement. Two different implant systems were used: Camlog (N=22; anterior areas) and Straumann tissue level (N=69; posterior areas). RESULTS: The survival rate for both implants and teeth was 100%. 19/21 (90%, 95%CI 82-95%), 16/21 (66%, 95%CI 66-84%), and 16/21 (66%, 95%CI 66-84%) patients were free of biological complications after 5 years, 10 years, and 15 years post-loading, respectively. 23/35 (90%, 95%CI 54-74%), 21/35 (61%, 95%CI 50-70%), and 21/35 (61%, 95%CI 50-70%) were free of technical complications following 5 years, 10 years, and 15 years post loading, respectively. CONCLUSIONS: Despite limitations of the study, the findings demonstrated that the use of a recently designed TI-FPD could be used for the tooth-implant connection in cases of partial edentulism and this may widen the treatment modalities by reducing the cost and need for extensive bone tissue augmentations. Further controlled longitudinal studies with larger patient groups are needed. Key words:Tooth-implant connection, dental implant, fixed partial dentures, complications, implant prosthodontics.

Cone Beam Computed Tomography Analysis of Root and Root Canal Morphology of First Permanent Lower Molars in a Middle East Subpopulation.

AIM: The aim of this study was to investigate variations in the number of roots and root canals in first permanent lower molars (FPLMs) using cone beam computed tomography (CBCT). MATERIALS AND METHODS: A total of 640 CBCT images were analyzed using SIDEXIS XG software version 2.62 (Sirona Dental Systems, Bensheim, Germany). The entire root anatomy of FPLMs was investigated in three dimensions and the number of roots, root canals, and the number of canals per root were recorded. Statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS) software, version 24, (IBM Corporation, USA) to determine the relationship between root anatomy and gender, age, or tooth location (right or left side). RESULTS: The majority of FPLMs had two roots (96%), whereas the remaining 32 FPLMs (4%) had three roots. Almost two-thirds of the sample (62.7%) had three root canals, whereas only three cases (0.4%) of the FPLMs had six canals. When comparing bilateral differences in the distribution of root canals, it was determined that a quarter of FPLMs (24.1%) had an unequal number of canals. Moreover, there were differences in the number of additional canals between the mesial and distal roots with 17.5% of the former having three canals as compared with only 0.5% of the distal root. Interestingly, not more than one canal was observed in all additional root cases. No significant differences were observed in the number of canals between males and females or between right and left sides of the examined FPLMs (P > 0.05). CONCLUSION: Dental clinicians should be aware of the presence of an additional root in 4% of FPLMs, and about a quarter of the cases (27%) had an extra middle mesial canal in the mesial root, which was found to be more prevalent in middle age groups.

A Review of Supernumerary Teeth in the Premolar Region.

Supernumerary teeth in the premolar region, unlike other supernumeraries, occur more often in the mandible where they are generally of the supplemental type. Occasionally, they are conical or smaller than normal, particularly in the upper premolar regions. They might occur singly or in multiples, be erupted or impacted, but the majority have been found to be unerupted and asymptomatic. The prevalence of supernumerary teeth in the premolar region has been demonstrated to be between 0.01 and 1 percent depending on the population studied. Interestingly, populations from the East or Africa are known to be the most affected. Various theories have been suggested to explain the etiology of supernumerary teeth in general including both genetic and environmental factors. Furthermore, it has been suggested that supernumerary premolar teeth belong to a third (postpermanent) series, developing from extensions of the dental lamina. Several consequences can result from the presence of supernumerary premolars, especially in the mandible, such as cyst formation, transposition, and other clinical scenarios.

Clinical Monitoring of Tooth Wear Progression in Patients over a Period of One Year Using CAD/CAM.

PURPOSE: The aim of this study was to clinically monitor the progression of tooth wear over a period of 1 year in a cohort of referred tooth wear patients through the use of a computer-aided design/computer-assisted manufacture (CAD/CAM) scanner and a standardized scanning/assessment methodology. MATERIALS AND METHODS: Polyether impressions were made of 11 participants (130 teeth) at baseline and at 1 year. Impressions were poured in type IV dental stone and the anterior teeth were 3D scanned. A surface-matching software was used to compare 1-year and baseline scans and identify any dimensional differences. RESULTS: Parafunctional habits were reported by all patients. All participants exhibited tooth wear ≥ 140 µm in depth and extending to ≥ 280 µm in at least one tooth. Maxillary central incisors were the most commonly and severely affected teeth. CONCLUSION: The ability of the developed CAD/CAM scanning methodology in clinical monitoring of tooth wear was demonstrated. Further research is needed to assess its practicality in large-scale epidemiologic tooth wear studies.

Longevity of fiber-reinforced composite fixed partial dentures (FRC FPD)-Systematic review.

OBJECTIVES: to assess FRC FPDs longevity through systematically reviewing contemporary clinical evidence. Population investigated comprised patients requiring replacement of a single missing anterior/posterior tooth. Intervention was FRC FPDs. No control/comparison selected. Outcome was longevity of FRC FPDs. The focus question was: 'What is the longevity of FRC FPDs used to replace one anterior or posterior tooth in patients?' DATA: Randomised, non-randomised, controlled, prospective and retrospective clinical studies were included. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses were applied. The Overall Strength of Clinical Recommendation (OSCR) was assessed using the Strength of Recommendation Taxonomy system. Survival of FPDs was assessed using the Kaplan-Meier method. Analysis of FPD-survival according to location and occurrence of different failures was performed using Logrank and Chi-square testing. SOURCES: PubMed, MEDLINE, and Web of Science databases were searched between January 2007 and December 2015. STUDY SELECTION: Nine studies were included, involving placement of 592 FRC FPDs in 463 patients. Follow-up periods ranged between 2 months and 8 years. Kaplan-Meier overall survival probability was 94.5% (95%C.I: 92.5%-96.5%) at 4.8 years. There was no significant difference in survival probability of anterior versus posterior FRC FPDs (P=0.278). Veneering material fracture/delamination occurred significantly more than other types of failures (Ps<0.05). A meta-analysis could not be performed. OSCR was moderate. CONCLUSIONS: FRC FPDs demonstrated high overall survival with predictable performance outcomes. However, long-term performance remains unclear. CLINICAL SIGNIFICANCE: FRC FPDs are viable medium-term management alternatives for replacing single anterior or posterior teeth in patients.

A Proposed Methodology to Assess the Accuracy of 3D Scanners and Casts and Monitor Tooth Wear Progression in Patients.

PURPOSE: The aim of this study was to detail and assess the capability of a novel methodology to 3D-quantify tooth wear progression in a patient over a period of 12 months. MATERIALS AND METHODS: A calibrated stainless steel model was used to identify the accuracy of the scanning system by assessing the accuracy and precision of the contact scanner and the dimensional accuracy and stability of casts fabricated from three different types of impression materials. Thereafter, the overall accuracy of the 3D scanning system (scanner and casts) was ascertained. Clinically, polyether impressions were made of the patient's dentition at the initial examination and at the 12-month review, then poured in type IV dental stone to assess the tooth wear. The anterior teeth on the resultant casts were scanned, and images were analyzed using 3D matching software to detect dimensional variations between the patient's impressions. RESULTS: The accuracy of the 3D scanning system was established to be 33 µm. 3D clinical analysis demonstrated localized wear on the incisal and palatal surfaces of the patient's maxillary central incisors. The identified wear extended to a depth of 500 µm with a distribution of 4% to 7% of affected tooth surfaces. CONCLUSION: The newly developed 3D scanning methodology was found to be capable of assessing and accounting for the various factors affecting tooth wear scanning. Initial clinical evaluation of the methodology demonstrates successful monitoring of tooth wear progression. However, further clinical assessment is needed.

Bacteria in the adventitia of cardiovascular disease patients with and without rheumatoid arthritis.

The incidence of atherosclerosis is significantly increased in rheumatoid arthritis (RA). Infection is one factor that may be involved in the pathogenesis of both diseases. The cause of RA and atherosclerosis is unknown, and infection is one of the factors that may be involved in the pathogenesis of both diseases. The aims of this study were to identify bacteria in the aortic adventitia of patients with cardiovascular disease (CVD) in the presence and absence of RA, and to determine the effect of identified candidate pathogens on Toll-like receptor (TLR)-dependent signalling and the proinflammatory response. The aortic adventitia of 11 CVD patients with RA (RA+CVD) and 11 CVD patients without RA (CVD) were collected during coronary artery bypass graft surgery. Bacteria were detected in four samples from CVD patients and three samples from RA+CVD patients and identified by 16S rRNA gene sequencing. Methylobacterium oryzae was identified in all three RA+CVD samples, representing 44.1% of the bacterial flora. The effect of M. oryzae on TLR-dependent signalling was determined by transfection of HEK-293 cells. Although mild TLR2 signalling was observed, TLR4 was insensitive to M. oryzae. Human primary macrophages were infected with M. oryzae, and a TLDA qPCR array targeting 90 genes involved in inflammation and immune regulation was used to profile the transcriptional response. A significant proinflammatory response was observed, with many of the up-regulated genes encoding proinflammatory cytokines (IL-1α, IL-1ß, IL-6, TNF-α) and chemokines (CCR7, IL-8). The aortic adventitia of CVD patients contains a wide range of bacterial species, and the bacterial flora is significantly less diverse in RA+CVD than CVD patients. M. oryzae may stimulate an proinflammatory response that may aggravate and perpetuate the pathological processes underlying atherosclerosis in RA patients.

A multidisciplinary intervention to reduce antibiotic duration in lower respiratory tract infections.

OBJECTIVES: Prolonged antibiotic courses are common in patients with lower respiratory tract infections (LRTIs) and contribute to antibiotic resistance and side effects. This study describes a multidisciplinary intervention to reduce antibiotic duration in LRTI patients. METHODS: This was a prospective before-and-after intervention study conducted from November 2011 to December 2012. Antibiotic duration was recorded for 6 months for all LRTI admissions (pneumonia, exacerbation of chronic obstructive pulmonary disease, exacerbation of asthma, and other LRTIs), followed by the introduction of an intervention intended to reduce the duration of antibiotic treatment. The intervention incorporated an antibiotic duration based on the CURB65 score, automatic stop dates and pharmacist feedback to prescribers. RESULTS: Two hundred and eighty-one patients were included in the pre-intervention group and 221 in the post-intervention group. The intervention resulted in a reduction in the duration of antibiotic treatment from 8.3 to 6.8 days (P < 0.001, 18.1% relative reduction). The rate of antibiotic-related adverse effects reduced from 31% to 19% (P = 0.03, 39.3% relative reduction). There was no increase in mortality or length of stay CONCLUSIONS: A simple intervention can significantly reduce antibiotic duration and antibiotic-related side effects.

Investigating the biological properties of carbohydrate derived fulvic acid (CHD-FA) as a potential novel therapy for the management of oral biofilm infections.

BACKGROUND: A number of oral diseases, including periodontitis, derive from microbial biofilms and are associated with increased antimicrobial resistance. Despite the widespread use of mouthwashes being used as adjunctive measures to control these biofilms, their prolonged use is not recommended due to various side effects. Therefore, alternative broad-spectrum antimicrobials that minimise these effects are highly sought after. Carbohydrate derived fulvic acid (CHD-FA) is an organic acid which has previously demonstrated to be microbiocidal against Candida albicans biofilms, therefore, the aims of this study were to evaluate the antibacterial activity of CHD-FA against orally derived biofilms and to investigate adjunctive biological effects. METHODS: Minimum inhibitory concentrations were evaluated for CHD-FA and chlorhexidine (CHX) against a range of oral bacteria using standardised microdilution testing for planktonic and sessile. Scanning electron microscopy was also employed to visualise changes in oral biofilms after antimicrobial treatment. Cytotoxicity of these compounds was assessed against oral epithelial cells, and the effect of CHD-FA on host inflammatory markers was assessed by measuring mRNA and protein expression. RESULTS: CHD-FA was highly active against all of the oral bacteria tested, including Porphyromonas gingivalis, with a sessile minimum inhibitory concentration of 0.5%. This concentration was shown to kill multi-species biofilms by approximately 90%, levels comparable to that of chlorhexidine (CHX). In a mammalian cell culture model, pretreatment of epithelial cells with buffered CHD-FA was shown to significantly down-regulate key inflammatory mediators, including interleukin-8 (IL-8), after stimulation with a multi-species biofilm. CONCLUSIONS: Overall, CHD-FA was shown to possess broad-spectrum antibacterial activity, with a supplementary function of being able to down-regulate inflammation. These properties offer an attractive spectrum of function from a naturally derived compound, which could be used as an alternative topical treatment strategy for oral biofilm diseases. Further studies in vitro and in vivo are required to determine the precise mechanism by which CHD-FA modulates the host immune response.