Perceptibility and acceptability of lightness difference of a single maxillary central incisor.

OBJECTIVES: The aim of this study was to assess the lightness difference perceptibility and acceptability thresholds, for a single maxillary central incisor, and to investigate possible differences in these thresholds regarding the direction (+ΔL* vs. -ΔL*), the observer group (dentists vs. laypersons), and the gender and age of the observers. MATERIALS AND METHODS: A series of images with varying lightness (L*), were created by altering the right maxillary central incisor of a male Caucasian, on a frontal view full-portrait image. Digital modification of one central incisor by 1 ΔL* unit resulted in 15 different images: one control, seven with increased and seven with decreased lightness. The images were presented in random order, on a digitally calibrated monitor, to 158 observers, grouped into 79 dentists, and 79 laypersons, who were asked to evaluate every image and answer whether they perceive a difference and if yes, whether they accept this difference. A multifactorial analysis of covariance was performed to analyze the perception and acceptance of any difference in the central incisors and to estimate the thresholds. The statistical significance level was α = 0.05. RESULTS: Overall, the magnitude of ΔL*, direction of ΔL*, observer group and age were each significant (p < 0.001), as was gender (p = 0.03). The effect of the magnitude of ΔL* interacted with its direction and the observer group (p = 0.045), and the effect of age interacted with the direction of ΔL*, and the gender and the group of the observers. Estimated 50%:50% perceptibility thresholds ranged from 0.1 to 2.7, and 50%:50% acceptability thresholds ranged from 2.3 to 4.5. Overall, dentists perceived lightness differences at lower magnitudes than laypersons; difference in lightness was perceived and accepted at lower magnitudes when the tooth become lighter instead of darker; and female observers perceived and accepted lightness differences at lower magnitudes compared to males. As age increased overall, differences of lightness were perceived and accepted at higher magnitudes. CONCLUSIONS: Perceptibility and acceptability of lightness differences of a single maxillary central incisor are affected by the magnitude and the direction of lightness change, as well as the gender, the age, and the type of the observers. CLINICAL SIGNIFICANCE: Even small changes in lightness are perceivable; however, thresholds of perception and acceptance are dependent on the magnitude and the direction of change and are also dependent on the observer, with women, dentists and younger people perceiving and accepting changes at lower magnitudes of ΔL*.

Identifying Features of a System of Practice to Inform a Contemporary Competency Framework for Paramedics in Canada.

INTRODUCTION: Paramedic practice is highly variable, occurs in diverse contexts, and involves the assessment and management of a range of presentations of varying acuity across the lifespan. As a result, attempts to define paramedic practice have been challenging and incomplete. This has led to inaccurate or under-representations of practice that can ultimately affect education, assessment, and the delivery of care. In this study, we outline our efforts to better identify, explore, and represent professional practice when developing a national competency framework for paramedics in Canada. METHODS: We used a systems-thinking approach to identify the settings, contexts, features, and influences on paramedic practice in Canada. This approach makes use of the role and influence of system features at the microsystem, mesosystem, exosystem, macrosystem, supra-macrosystem, and chronosystem levels in ways that can provide new insights. We used methods such as rich pictures, diagramming, and systems mapping to explore relationships between these contexts and features. FINDINGS: When we examine the system of practice in paramedicine, multiple layers become evident and within them we start to see details of features that ought to be considered in any future competency development work. Our exploration of the system highlights that paramedic practice considers the person receiving care, caregivers, and paramedics. It involves collaboration within co-located and dispersed teams that are composed of other health and social care professionals, public safety personnel, and others. Practice is enacted across varying geographical, cultural, social, and technical contexts and is subject to multiple levels of policy, regulatory, and legislative influence. CONCLUSION: Using a systems-thinking approach, we developed a detailed systems map of paramedic practice in Canada. This map can be used to inform the initial stages of a more representative, comprehensive, and contemporary national competency framework for paramedics in Canada.

Six-Month Pilot Testing of a Digital Health Tool to Support Effective Self-Care in People With Heart Failure: Mixed Methods Study.

BACKGROUND: Digital tools may support people to self-manage their heart failure (HF). Having previously outlined the human-centered design development of a digital tool to support self-care of HF, the next step was to pilot the tool over a period of time to establish people's acceptance of it in practice. OBJECTIVE: This study aims to conduct an observational pilot study to examine the usability, adherence, and feasibility of a digital health tool for HF within the Irish health care system. METHODS: A total of 19 participants with HF were provided with a digital tool comprising a mobile app and the Fitbit Charge 4 and Aria Air smart scales for a period of 6 months. Changes to their self-care were assessed before and after the study with the 9-item European HF Self-care Behavior Scale (EHFScBS) and the Minnesota Living with HF Questionnaire (MLwHFQ) using a Wilcoxon signed rank test. After the study, 3 usability questionnaires were implemented and descriptively analyzed: the System Usability Scale (SUS), Wearable Technology Motivation Scale (WTMS), and Comfort Rating Scale (CRS). Participants also undertook a semistructured interview regarding their experiences with the digital tool. Interviews were analyzed deductively using the Theoretical Domains Framework. RESULTS: Participants wore their devices for an average of 86.2% of the days in the 6-month testing period ranging from 40.6% to 98%. Although improvements in the EHFScBS and MLwHFQ were seen, these changes were not significant (P=.10 and P=.70, respectively, where P>.03, after a Bonferroni correction). SUS results suggest that the usability of this system was not acceptable with a median score of 58.8 (IQR 55.0-60.0; range 45.0-67.5). Participants demonstrated a strong motivation to use the system according to the WTMS (median 6.0, IQR 5.0-7.0; range 1.0-7.0), whereas the Fitbit was considered very comfortable as demonstrated by the low CRS results (median 0.0, IQR 0.0-0.0; range 0.0-2.0). According to participant interviews, the digital tool supported self-management through increased knowledge, improved awareness, decision-making, and confidence in their own data, and improving their social support through a feeling of comfort in being watched. CONCLUSIONS: The digital health tool demonstrated high levels of adherence and acceptance among participants. Although the SUS results suggest low usability, this may be explained by participants uncertainty that they were using it fully, rather than it being unusable, especially given the experiences documented in their interviews. The digital tool targeted key self-management behaviors and feelings of social support. However, a number of changes to the tool, and the health service, are required before it can be implemented at scale. A full-scale feasibility trial conducted at a wider level is required to fully determine its potential effectiveness and wider implementation needs.

Informed development of a multi-species biofilm in chronic obstructive pulmonary disease.

Recent evidence indicates that microbial biofilm aggregates inhabit the lungs of COPD patients and actively contribute towards chronic colonization and repeat infections. However, there are no contextually relevant complex biofilm models for COPD research. In this study, a meta-analysis of the lung microbiome in COPD was used to inform development of an optimized biofilm model composed of genera highly associated with COPD. Bioinformatic analysis showed that although diversity matrices of COPD microbiomes were similar to healthy controls, and internal compositions made it possible to accurately differentiate between these cohorts (AUC = 0.939). Genera that best defined these patients included Haemophilus, Moraxella and Streptococcus. Many studies fail to account for fungi; therefore, Candida albicans was included in the creation of an interkingdom biofilm model. These organisms formed a biofilm capable of tolerating high concentrations of antimicrobial therapies with no significant reductions in viability. However, combined therapies of antibiotics and an antifungal resulted in significant reductions in viable cells throughout the biofilm (p < 0.05). This biofilm model is representative of the COPD lung microbiome and results from in vitro antimicrobial challenge experiments indicate that targeting both bacteria and fungi in these interkingdom communities will be required for more positive clinical outcomes.

Nitrate reduction capacity of the oral microbiota is impaired in periodontitis: potential implications for systemic nitric oxide availability.

The reduction of nitrate to nitrite by the oral microbiota has been proposed to be important for oral health and results in nitric oxide formation that can improve cardiometabolic conditions. Studies of bacterial composition in subgingival plaque suggest that nitrate-reducing bacteria are associated with periodontal health, but the impact of periodontitis on nitrate-reducing capacity (NRC) and, therefore, nitric oxide availability has not been evaluated. The current study aimed to evaluate how periodontitis affects the NRC of the oral microbiota. First, 16S rRNA sequencing data from five different countries were analyzed, revealing that nitrate-reducing bacteria were significantly lower in subgingival plaque of periodontitis patients compared with healthy individuals (P < 0.05 in all five datasets with n = 20-82 samples per dataset). Secondly, subgingival plaque, saliva, and plasma samples were obtained from 42 periodontitis patients before and after periodontal treatment. The oral NRC was determined in vitro by incubating saliva with 8 mmol/L nitrate (a concentration found in saliva after nitrate-rich vegetable intake) and compared with the NRC of 15 healthy individuals. Salivary NRC was found to be diminished in periodontal patients before treatment (P < 0.05) but recovered to healthy levels 90 days post-treatment. Additionally, the subgingival levels of nitrate-reducing bacteria increased after treatment and correlated negatively with periodontitis-associated bacteria (P < 0.01). No significant effect of periodontal treatment on the baseline saliva and plasma nitrate and nitrite levels was found, indicating that differences in the NRC may only be revealed after nitrate intake. Our results suggest that an impaired NRC in periodontitis could limit dietary nitrate-derived nitric oxide levels, and the effect on systemic health should be explored in future studies.

Examining the acceptability and feasibility of the Compassionate Mindful Resilience (CMR) programme in adults living with chronic kidney disease: the COSMIC study findings.

BACKGROUND: Individuals with chronic kidney disease experience difficult physical and psychological symptoms, that impact quality of life, and are at increased risk of anxiety and depression. Access to specialist psychological support is limited. This study aimed to support a new service development project, in collaboration with Kidney Care UK, to implement the Compassionate Mindful Resilience (CMR) programme, developed by MindfulnessUK, which provides accessible mindfulness techniques and practices to enhance compassion and resilience, and explore its feasibility for people living with stage 4 or 5 kidney disease and transplant. METHODS: A multi-method feasibility design was utilised. Participants over 18 years, from the UK, with stage 4 or 5 kidney disease or post-transplant, and who were not currently undergoing psychotherapy, were recruited to the four-week CMR programme. Data was collected at baseline, post-intervention and three-months post to measure anxiety, depression, self-compassion, mental wellbeing, resilience, and mindfulness. The acceptability of the intervention for a kidney disease population was explored through qualitative interviews with participants, and the Mindfulness Teacher. RESULTS: In total, 75 participants were recruited to the study, with 65 completing the CMR programme. The majority were female (66.2%) and post-transplant (63.1%). Analysis of completed outcome measures at baseline and post-intervention timepoints (n = 61), and three-months post intervention (n = 45) revealed significant improvements in participant's levels of anxiety (p < .001) and depression (p < .001), self-compassion (p = .005), mental wellbeing (p < .001), resilience (p.001), and mindfulness (p < .001). Thematic analysis of interviews with participants (n = 19) and Mindfulness Teacher (n = 1) generated three themes (and nine-subthemes); experiences of the CMR programme that facilitated subjective benefit, participants lived and shared experiences, and practicalities of programme participation. All participants interviewed reported that they found programme participation to be beneficial. CONCLUSION: The findings suggest that the CMR programme has the potential to improve psychological outcomes among people with chronic kidney disease. Future randomized controlled trials are required to further test its effectiveness.

A heterogenous population of extracellular vesicles mobilize to the alveoli postinjury.

BACKGROUND: Acute lung injury and subsequent resolution following severe injury are coordinated by a complex lung microenvironment that includes extracellular vesicles (EVs). We hypothesized that there is a heterogenous population of EVs recruited to the alveoli postinjury and that we could identify specific immune-relevant mediators expressed on bronchoalveolar lavage (BAL) EVs as candidate biomarkers of injury and injury resolution. METHODS: Mice underwent 30% TBSA burn injury and BAL fluid was collected 4 hours postinjury and compared with sham. Extracellular vesicles were purified and single vesicle flow cytometry (vFC) was performed using fluorescent antibodies to quantify the expression of specific cell surface markers on individual EVs. Next, we evaluated human BAL specimens from injured patients to establish translational relevance of the mouse vFC analysis. Human BAL was collected from intubated patients following trauma or burn injury, EVs were purified, then subjected to vFC analysis. RESULTS: A diverse population of EVs were mobilized to the alveoli after burn injury in mice. Quantitative BAL vFC identified significant increases in macrophage-derived CD44+ EVs (preinjury, 10.8% vs. postinjury, 13%; p < 0.05) and decreases in IL-6 receptor alpha (CD126) EVs (preinjury, 19.3% vs. postinjury, 9.3%, p < 0.05). Bronchoalveolar lavage from injured patients also contained a heterogeneous population of EVs derived from myeloid cells, endothelium, and epithelium sources, with CD44+ EVs being highly detected. CONCLUSION: Injury causes mobilization of a heterogeneous population of EVs to the alveoli in both animal models and injured patients. Defining EV release after injury will be critical in identifying diagnostic and therapeutic targets to limit postinjury acute lung injury.

Ostomy Management for Pediatric Perianal Crohn's Disease.

INTRODUCTION: Pediatric patients with perianal Crohn's Disease (CD) suffer recalcitrant fistulas, abscesses, and strictures. Fecal diversion is a palliative last resort, but the expected clinical course and long-term management of the ostomy for this population is unclear. We sought to identify factors predictive of ostomy takedown and establish management recommendations for fistulizing and stenosing disease. METHODS: We reviewed our institutional registry for patients aged 1-18 years with CD who received perianal surgery from 2011 to 2021. We analyzed medical therapy, examinations under anesthesia (EUA), fistula and stenosis response, and rates of fecal diversion and reversal. RESULTS: There were 109 patients with fistulizing CD and 21 with stenosing CD. There were 8 diverted for fistula and 4 due to stricture [8/109 (7 %) vs 4/21 (19 %), p = 0.213]. Three patients with fistulizing disease had their ostomy reversed at an average of 1.46 years. Each demonstrated consistent CD control and with no additional perianal flares. The remainder have been diverted 3.15 ± 4.57 years with 2.1 ± 2.8 EUAs. Only one patient with stricture was durably reversed, but they still require serial anal dilation. Two were reversed but required re-diversion due to stricture progression. CONCLUSION: Reversal rates after fecal diversion for pediatric perianal CD remain disappointingly low and diversion does not obviate the possibility of future EUAs. While reversal was successful for medically responsive patients with fistulizing disease, those with stenosing disease remained dependent on anal dilations and were more likely to fail reversal. Fecal diversion does nothing to reverse an established stricture and such patients will likely need to decide between indefinite dilations or permanent ostomy. LEVEL OF EVIDENCE: IV. TYPE OF STUDY: Retrospective review.

Evaluation of Prosthetic Complications with Metal-Acrylic Resin Implant-Fixed Complete Dentures: A Medium- and Long-Term Retrospective Analysis with Up to 13 Years of Follow-up

PURPOSE: To present prosthetic complications observed in the medium and long term in patients treated with metal-acrylic resin implant-supported fixed complete dentures (MAIFCDs). MATERIALS AND METHODS: A total of 87 patients who were treated with MAIFCDs were included. Acrylic resin (denture teeth and base) fracture, screw loosening (prosthetic or abutment), screw (prosthetic or abutment), and framework fracture were analyzed for descriptive statistics. Product-limit survival estimates were used for the cumulative no-complication rate (CNCR) of prostheses. All results were assessed using α = .05. RESULTS: The average observation time was 42.9 months (range: 19 to 153). Of 597 implants, 8 mandibular (44.4%) and 10 maxillary implants (55.6%) failed. In total, 29 patients (33.3%) experienced no complications in an average of 7 years, and 58 patients (66.6%) experienced at least one complication. The average time for the first complication to occur was 23 months (range: 1 to 97 months). The average number of complications was 5.9/patient. Acrylic resin complications were the most frequent, followed by screw loosening, screw fracture, and framework fracture. Of those patients with complications, 9 (16%) had maxillary MAIFCDs with an average of 4 complications. In total, 28 patients (48%) had only mandibular MAIFCDs with an average of 5 complications, and 21 patients (36%) had both arches treated with MAIFCDs with an average of 9 complications. Mandibular MAIFCDPs in women had a higher CNCR compared to maxillary MAIFCDs of both women and men and when both arches of women were treated with MAIFCDs (P < .05). CONCLUSIONS: The CNCR of MAIFCDs differed depending on the arch treated and sex. Mandibular MAIFCDs in women had a lower complication rate than MAIFCDs in other arch-sex pairs. Acrylic resin related complications were commonly observed as well as prosthetic screw loosening.

Experiences of People with Kidney Disease Following the Implementation of the Compassionate Mindful Resilience Programme: Qualitative Findings from the COSMIC Study.

BACKGROUND: Kidney disease is a progressive, debilitating condition. Patients experience challenging physical and psychological symptoms and are at increased risk of anxiety, depression, and poor mental wellbeing. Access to specialist psychological or social support is limited, with inadequate provision of psychosocial support available across UK renal units. The COSMIC study (examining the acceptability and feasibility of the Compassionate Mindful Resilience programme for adult patients with chronic kidney disease) aimed to support a new service development project, in partnership with Kidney Care UK, by implementing the Compassionate Mindful Resilience (CMR) programme, developed by MindfulnessUK, and explore its feasibility for patients with stage 4 or 5 kidney disease and kidney transplant recipients. This paper reports on the qualitative exploratory work which examined the experiences of study participants, their adherence to practice, and the acceptability of the intervention. METHOD: Participants (n = 19) took part in semi-structured interviews, which were transcribed, coded, and thematically analysed. RESULTS: Three themes (and nine subthemes) were reported: experiences of the CMR programme that facilitated subjective benefit, participants' lived and shared experiences, and the practicalities of CMR programme participation. All participants reported that they found taking part in the CMR programme to be a beneficial experience. CONCLUSION: The CMR programme was found to be an acceptable intervention for people living with kidney disease and provided tools and techniques that support the mental health and wellbeing of this patient group. Further qualitative exploration into participant experience should be integrated within future trials of this intervention.

Positional trueness of three removable die designs with different root geometries manufactured using stereolithographic 3D printing.

STATEMENT OF PROBLEM: Three-dimensional (3D) printed casts are a suitable alternative to dental stone casts. Contemporary dental design computer programs permit designing definitive casts with removable dies with different root geometries and retention mechanisms. Studies on the positional trueness of 3D-printed removable dies with different root geometries are lacking. PURPOSE: The purpose of this in vitro study was to investigate the 3D displacements of three 3D-printed removable die designs with different root geometries. MATERIAL AND METHODS: The digital file of a dental stone alveolar cast with root-form removable dies (MOD UJ IV Fixed Prosthetics; Ivoclar AG) was used as a reference to create 3 removable die and alveolar cast designs (Root Form, RF; Conical, CON; Cylindric, CYL) with different root geometries in 2 dental design computer programs (DentalCAD 3.1 Rijeka; exocad; GmbH; InLab CAD 22.0; Dentsply Sirona). 3 equidistant Ø1-mm spheres (C, Cervical; M, Middle; O, Occlusal) were designed on the buccal surface of the coronal portion of the removable die to evaluate their displacement. A total of 45 alveolar casts with 45 removable dies were fabricated using a stereolithographic 3D printer (Form 3; Formlabs); each die group consisted of 15 specimens. After fabrication and postprocessing, the specimens were scanned, and their digital files were analyzed in a metrology-grade computer program to evaluate the displacement of the removable dies with respect to the position of the die in the master reference file. Subsequently, the data were analyzed using a 3-way analysis of variance (ANOVA) followed by step-down Bonferroni-corrected pairwise comparisons (α=.05). RESULTS: Two statistically significant 2-way interactions were detected between the independent variables, die design and direction (P<.001), and location and direction (P<.001). The post hoc analysis identified significant differences between the displacement values of RF and CYL (P<.001) and RF and the CON (P<.001) designs on the Y axis. The measured displacements were statistically different between the C and O locations on the Y axis (P=.001) and the M and O locations on the Z axis (P=.006). CONCLUSIONS: The root geometry of a 3D-printed removable die and alveolar cast can affect seating, and variable degrees of tipping of the removable die can be seen. The seating and congruence of the removable die with the interocclusal space and relationships observed intraorally should be confirmed before adjusting indirect restorations.

Cell Count and Cell Density Decrease as Age Increases in Cadaveric Pediatric Medial Menisci.

Purpose: To examine the histologic changes in terms of cellularity, cell density, and nuclear shape in medial meniscal cellularity during skeletal development using pediatric cadaver specimens. Methods: Medial menisci from 26 pediatric cadavers, 11 female and 15 male (total 36 menisci), were obtained from tissue bank. Mean age of female donors was 34 months (1-108 months) and of male donors was 52 months (1-132 months). Menisci were processed and embedded in paraffin blocks. Each tissue block containing 6 representative areas of meniscus (anterior root, anterior horn, body [n = 2], posterior horn, and posterior root) was sectioned at 4 microns and stained with hematoxylin and eosin for evaluation of chondrocyte nuclei. Each of the 6 representative areas was imaged at 10×; one image on peripheral one-third of section, the second image on central two-thirds of the section. FIJI imaging software was used to measure cell count, cell density, and nuclear morphology (1 = perfect circle). Data analysis included linear mixed models, Type II analysis of variance tests, and pairwise tests with the Tukey correction to assess statistical significance. Results: Peripheral meniscus was more cellular than central meniscus. The cell count was found to decrease by 14% per year of age. Peripheral cell count decreased at a rate similar to the cell count in the central meniscus. Meniscal cell density was 2× higher peripherally than centrally. Overall average cell density in all locations in the menisci decreased by an average of 14% per year of age. Conclusions: The results of this study reveal decreases in cell count, cell density, and circularity as age increases in cadaveric pediatric medial menisci. Clinical Relevance: To better understand the development of pediatric menisci at a cellular level and use this knowledge in the future on how to maintain the menisci in a younger, healthier state.

Cardiovascular disease behavioural risk factors in rural interventions: cross-sectional study.

This study aims to (1) assess the distribution of variables within the population and the prevalence of cardiovascular disease (CVD) behavioural risk factors in patients, (2) identify target risk factor(s) for behaviour modification intervention, and (3) develop an analytical model to define cluster(s) of risk factors which could help make any generic intervention more targeted to the local patient population. Study patients with at least one CVD behavioural risk factor living in a rural region of the Scottish Highlands. The study used the STROBE methodology for cross-sectional studies. Demographic and clinical data of patients (n = 2025) in NHS Highlands hospital were collected at the point of admission for PCI between 04.01.2016 and 31.12.2019. Collected data distributions were analysed by CVD behavioural risk factors for prevalence, associations, and direction of associations. Cluster definition was measured by assignment of a unit score each for the overall level of prevalence and significance of associations, and general logistics modelling for direction and significance of the risk. The mean (SD) age was 69.47(± 10.93) years [95% CI (68.99-69.94)]. The key risk factors were hyperlipidaemia, hypertension, and elevated body mass index (BMI). Approximately 40% of the population have multiple risk factor counts of two. Analytical measures revealed a population risk factor cluster with elevated BMI [77.5% (1570/2025)] that is mostly either hyperlipidaemic [9.43%, co-eff. (17), P = 0.007] or hypertensive [22.72%, co-eff. (17), P = 0.99] as key risk factor clusters. Carefully modelled analyses revealed clustered risk associated with elevated BMI. This information would support a strategy for targeting risk factor clusters in novel interventions to improve implementation efficiency. Exposure to and outcome of an elevated BMI is linked more to the population's socio-economic outcomes rather than to regional rurality or urbanity.

A majority of trauma-related deep venous thromboses resolve prior to discharge.

Post-traumatic DVTs present unique challenges in patient populations with specific high-risk injury patterns. Duplex ultrasound (US) can be used to assess evolution of DVTs and may guide treatment for high-risk patients. We hypothesized that many DVTs resolve during the initial admission. Weekly duplex US are ordered on all trauma inpatients regardless of prior DVT at our facility. We reviewed US and outcomes data on all patients with lower extremity DVTs at our Level I trauma center from January 2012-December 2021. 392 patients were diagnosed with lower extremity DVT by US. 261 (67%) patients received follow-up US with a mean time to repeat US of 6 days. Of these, 91 (35%) patients experienced DVT resolution prior to the first follow-up US, and 141 (54%) patients experienced resolution prior to discharge. Mean time to resolution was 10 days. Over 50% of DVTs resolve before discharge and are detected by US. Further studies and post-discharge follow-up are needed to determine if patients with resolved DVTs can be managed without therapeutic anticoagulation.

Nitrate and a nitrate-reducing Rothia aeria strain as potential prebiotic or synbiotic treatments for periodontitis.

A few studies indicate that nitrate can reduce dysbiosis from a periodontitis point of view. However, these experiments were performed on samples from healthy individuals, and it is unknown if nitrate will be effective in periodontal patients, where the presence of nitrate-reducing bacteria is clearly reduced. The aim of this study was to test the effect of nitrate and a nitrate-reducing R. aeria (Ra9) on subgingival biofilms of patients with periodontitis. For this, subgingival plaque was incubated with 5 mM nitrate for 7 h (n = 20) or 50 mM nitrate for 12 h (n = 10), achieving a ~50% of nitrate reduction in each case. Additionally, Ra9 was combined with 5 mM nitrate (n = 11), increasing the nitrate reduced and nitrite produced (both p < 0.05). The addition of nitrate to periodontitis communities decreased biofilm mass (50 mM > 5 mM, both p < 0.05). Five millimolar nitrate, 50 mM nitrate and 5 mM nitrate + Ra9 led to 3, 28 and 20 significant changes in species abundance, respectively, which were mostly decreases in periodontitis-associated species. These changes led to a respective 15%, 63% (both p < 0.05) and 6% (not significant) decrease in the dysbiosis index. Using a 10-species biofilm model, decreases in periodontitis-associated species in the presence of nitrate were confirmed by qPCR (all p < 0.05). In conclusion, nitrate metabolism can reduce dysbiosis and biofilm growth of periodontitis communities. Five millimolar nitrate (which can be found in saliva after vegetable intake) was sufficient, while increasing this concentration to 50 mM (which could be achieved by topical applications such as a periodontal gel) increased the positive effects. Ra9 increased the nitrate metabolism of periodontitis communities and should be tested in vivo.

The Physical Compatibility of Glycopyrrolate and Rocuronium.

OBJECTIVE: Scientific evidence has rarely, if at all, been reported in the literature demonstrating analytical confirmation of the physical compatibility and stability of glycopyrrolate and rocuronium combined. The purpose of this experiment was to determine if glycopyrrolate and rocuronium are physically compatible. METHODS: Glycopyrrolate and rocuronium were combined in various containers, observed over a 60-minute period, and compared against positive and negative controls. Measured metrics included color change, precipitate formation, Tyndall beam test, turbidity, and pH. Statistical analyses were used to assess significance of data trends. RESULTS: The combination of glycopyrrolate and rocuronium did not result in any color change, precipitate formation, a positive Tyndall beam test, or a significantly positive turbidity and did not result in any significant change in pH, regardless of container. CONCLUSION: Per the protocol used in this study, glycopyrrolate and rocuronium were determined to be physically compatible.

Effect of cross-polarization filters on the trueness of colors obtained with a single-lens reflex camera, macro lens, and a ring flash.

OBJECTIVE: To investigate the effect of cross-polarization filters on the colors of shade tabs obtained with a digital single-lens reflex (DSLR) camera, macrolens, and a ring flash. MATERIALS AND METHODS: Digital images of four shade tables (1M1, 3L2.5, 3R2.5, and 5M3) from the VITA Toothguide 3D-Master shade guide were taken using a DSLR camera, 100 mm macrolens, and ring flash with two different cross-polarizing filters (Polar_eyes and Filtropolar), and without (Nonpolarizer; n = 7). The CIE L*a*b* color coordinates of digital images were calculated and remeasured with a spectroradiometer (SR). The color differences (ΔE00 ) between the SR and digital images were calculated and analyzed with the two-way analysis of variance (ANOVA) and Tukey HSD test (α = 0.05). RESULTS: ΔE00 values of all test groups were higher than the clinically acceptable threshold (∆E00 > 1.80). While the ∆E00 values of Filtropolar (6.19 ± 0.44) and Polar_eyes (7.82 ± 0.23) groups were significantly higher than the Nonpolarizer (4.69 ± 0.32) for the 1M1 shade tab, ∆E00 value of Polar_eyes (6.23 ± 0.34) was significantly lower than Nonpolarizer (10.71 ± 0.48) group for 5M3 shade tab (p < 0.05). CONCLUSION: The color-matching results of tested digital photography techniques with and without cross-polarization were unacceptable, compared to a spectroradiometer. While digital photography with Polar_eyes cross-polarizing filter has closer results to the reference device for the low-in-value shade table (5M3), for the high-in-value shade table (1M1), improved results were obtained without a cross-polarizing filter. CLINICAL SIGNIFICANCE: The cross-polarization filters are increasingly used in dentistry for tooth color communication with digital photography techniques. However, the digital photography techniques with-without cross-polarization filterers should be improved to obtain clinically acceptable color-matching results.

Effect of monomer composition and filler fraction on surface microhardness and depth of cure of experimental resin composites.

This study evaluated microhardness profiles and calculated depths of cure at 80% of the surface microhardness of experimental dental resin composites having different base monomer compositions and different filler fractions. Composites were prepared using four different base monomers (bisphenol A-glycidyl methacrylate [Bis-GMA], urethane dimethacrylate [UDMA], ethoxylated bisphenol-A dimethacrylate [Bis-EMA], and Fit-852) with triethylene glycol dimethacrylate (TEGDMA) used as a co-monomer at three filler:resin matrix weight percent fractions (50:50, 60:40, and 70:30). Uncured material was placed in 3D printed molds and light cured for 40 s from the top surface only. Knoop microhardness was measured at the top of the specimen, and at every 0.5 mm up to 4 mm in depth. Microhardness at the surface increased in all experimental composites as the filler fraction increased. When comparing base monomers, microhardness was the highest in UDMA-based composites, while Bis-GMA-based composites showed the lowest values. When comparing depth of cure as a function of base monomer type, both Bis-GMA and Bis-EMA showed significantly lower values than UDMA or Fit-852. Composites having 50 wt% filler showed a significantly higher depth of cure than those with 60 and 70 wt% filler. Base monomer and filler fraction significantly influence microhardness and depth of cure in these experimental composites.

Longitudinal changes in subgingival biofilm composition following periodontal treatment.

BACKGROUND: Current periodontal treatment involves instrumentation using hand and/or ultrasonic instruments, which are used either alone or in combination based on patient and clinician preference, with comparable clinical outcomes. This study sought to investigate early and later changes in the subgingival biofilm following periodontal treatment, to identify whether these changes were associated with treatment outcomes, and to investigate whether the biofilm responded differently to hand compared with ultrasonic instruments. METHODS: This was a secondary-outcome analysis of a randomized-controlled trial. Thirty-eight periodontitis patients received full-mouth subgingival instrumentation using hand (n = 20) or ultrasonic instrumentation (n = 18). Subgingival plaque was sampled at baseline and 1, 7, and 90 days following treatment. Bacterial DNA was analyzed using 16S rRNA sequencing. Periodontal clinical parameters were evaluated before and after treatment. RESULTS: Biofilm composition was comparable in both (hand and ultrasonics) treatment groups at all time points (all genera and species; p[adjusted] > 0.05). Large-scale changes were observed within groups across time points. At days 1 and 7, taxonomic diversity and dysbiosis were reduced, with an increase in health-associated genera including Streptococcus and Rothia equating to 30% to 40% of the relative abundance. When reassessed at day 90 a subset of samples reformed a microbiome more comparable with baseline, which was independent of instrumentation choice and residual disease. CONCLUSIONS: Hand and ultrasonic instruments induced comparable impacts on the subgingival plaque microbiome. There were marked early changes in the subgingival biofilm composition, although there was limited evidence that community shifts associated with treatment outcomes.