Longevity of dental restorations in Sjogren's disease patients using electronic dental and health record data.

BACKGROUND: Decreased salivary secretion is not only a risk factor for carious lesions in Sjögren's disease (SD) but also an indicator of deterioration of teeth with every restorative replacement. This study determined the longevity of direct dental restorations placed in patients with SD using matched electronic dental record (EDR) and electronic health record (EHR) data. METHODS: We conducted a retrospective cohort study using EDR and EHR data of Indiana University School of Dentistry patients who have a SD diagnosis in their EHR. Treatment history of patients during 15 years with SD (cases) and their matched controls with at least one direct dental restoration were retrieved from the EDR. Descriptive statistics summarized the study population characteristics. Cox regression models with random effects analyzed differences between cases and controls for time to direct restoration failure. Further the model explored the effect of covariates such as age, sex, race, dental insurance, medical insurance, medical diagnosis, medication use, preventive dental visits per year, and the number of tooth surfaces on time to restoration failure. RESULTS: At least one completed direct restoration was present for 102 cases and 42 controls resulting in a cohort of 144 patients' EDR and EHR data. The cases were distributed as 21 positives, 57 negatives, and 24 uncertain cases based on clinical findings. The average age was 56, about 93% were females, 54% were White, 74% had no dental insurance, 61% had public medical insurance, < 1 preventive dental visit per year, 94% used medications and 93% had a medical diagnosis that potentially causes dry mouth within the overall study cohort. About 529 direct dental restorations were present in cases with SD and 140 restorations in corresponding controls. Hazard ratios of 2.99 (1.48-6.03; p = 0.002) and 3.30 (1.49-7.31, p-value: 0.003) showed significantly decreased time to restoration failure among cases and positive for SD cases compared to controls, respectively. Except for the number of tooth surfaces, no other covariates had a significant influence on the survival time. CONCLUSION: Considering the rapid failure of dental restorations, appropriate post-treatment assessment, management, and evaluation should be implemented while planning restorative dental procedures among cases with SD. Since survival time is decreased with an increase in the number of surfaces, guidelines for restorative procedures should be formulated specifically for patients with SD.

Fasting C-peptide values among adolescents in the National Health and Nutrition Examination Surveys.

AIM: To report fasting C-peptide values and variations across demographics in healthy non-diabetic adolescents included in the National Health and Nutrition Examination Surveys (NHANES) dataset. RESEARCH DESIGN AND METHODS: In this analysis, we used fasting C-peptide data from the 1999 to 2004 NHANES dataset for participants aged 12 to <18 years (n = 2063). RESULTS: The mean ± SE age of the participants was 14.99 ± 0.06 years. The participants included 992 girls and 1071 boys, and more than 80% of participants had a body mass index (BMI) percentile of <85%. Among boys, the most notable finding was the increase in geometric mean C-peptide level from 0.51 nmol/L at age 12, to 0.65 nmol/L at age 15 years. Among girls, levels fluctuated around a geometric mean of 0.67 nmol/L. Girls had significantly higher mean log-transformed C-peptide concentrations than boys (P < 0.0001) after adjusting for age, race and BMI percentile category. After adjusting for age and BMI percentile category, non-Hispanic Black boys and girls had significantly lower C-peptide levels than non-Hispanic White (P = 0.0026 and P = 0.0093) and Mexican American boys and girls (P < 0.0001 and P < 0.0001), respectively. Despite these findings, both insulin and homeostatic model assessment of insulin resistance were greater in non-Hispanic Black compared to non-Hispanic White participants. CONCLUSIONS: Here we describe fasting C-peptide levels in a non-diabetic adolescent population. These data provide crucial insight into evaluating racial differences in endogenous insulin release and clearance and will provide novel information which can be used in assessing residual ß-cell function and response to intervention therapy.

Whole-Spine MRI in Children With Suspected Abusive Head Trauma.

BACKGROUND. Abusive head trauma (AHT) in children has recently been associated with findings on cervical spine MRI. OBJECTIVE. The purpose of this study was to evaluate whether whole-spine MRI in children with suspected AHT shows additional abnormalities not identified on cervical spine MRI. METHODS. This retrospective study included 256 children younger than 3 years old (170 boys, 86 girls; mean age, 5.9 months) who underwent skeletal survey and head MRI for suspected child abuse from January 2019 to December 2020. Per institutional protocol, children with suspected AHT also underwent whole-spine MRI. AHT diagnoses were established by a combination of clinical information from medical record review and injuries described in reports from skeletal survey, head MRI, and head CT (if performed). Two pediatric neuroradiologists independently reviewed whole-spine MRI examinations for presence and level of intraspinal hemorrhage (classified as subarachnoid, subdural, or epidural), ligamentous injury, spinal cord edema, and vertebral fractures; subdural hematoma, epidural hematoma, ligamentous injury, and fracture unidentified by skeletal survey were considered major findings. Interobserver agreement was assessed; a third radiologist resolved discrepancies. Findings were summarized with attention to injuries isolated to the thoracolumbar spine. RESULTS. A total of 148 of 256 (57.8%) children underwent whole-spine MRI. AHT was diagnosed in 79 of 148 (53.4%) children who underwent whole-spine MRI versus in 2 of 108 (1.9%) who did not undergo whole-spine MRI (p < .001). Interobserver agreement, expressed as kappa coefficient, was 0.90 for intraspinal hemorrhage, 0.69 for ligamentous injury, 0.66 for spinal cord edema, and 0.95 for fracture. A total of 57 of 148 (38.5%) whole-spine MRI examinations showed injuries, and 34 of 148 (23.0%) showed injuries localized to the thoracolumbar spine. A total of 47 of 148 (31.8%) whole-spine MRI examinations showed major findings, of which 24 (51.1%) were localized to the thoracolumbar spine. Isolated thoracolumbar injuries included 23 of 34 spinal subdural hematomas, 2 of 3 spinal epidural hematomas, and 9 of 11 vertebral fractures, including five fractures not identified by skeletal survey. Diagnosis of AHT was more common in children with positive, versus negative, whole-spine MRI examinations (76.8% vs 39.1%; p < .001). CONCLUSION. In children with suspected AHT, whole-spine MRI commonly shows isolated thoracolumbar injuries. CLINICAL IMPACT. The results support performing whole-spine MRI rather than cervical spine MRI in children with suspected AHT.

Radiologists' Diagnostic Performance in Differentiation of Rickets and Classic Metaphyseal Lesions on Radiographs: A Multicenter Study.

BACKGROUND. Despite evidence supporting the specificity of classic metaphyseal lesions (CML) for the diagnosis of child abuse, some medicolegal practitioners claim that CML result from rickets rather than trauma. OBJECTIVE. The purpose of this study was to evaluate radiologists' diagnostic performance in differentiating rickets and CML on radiographs. METHODS. This retrospective seven-center study included children younger than 2 years who underwent knee radiography from January 2007 to December 2018 and who had either rickets (25-hydroxyvitamin D level < 20 ng/mL and abnormal knee radiographs) or knee CML and a diagnosis of child abuse from a child abuse pediatrician. Additional injuries were identified through medical record review. Radiographs were cropped and zoomed to present similar depictions of the knee. Eight radiologists independently interpreted radiographs for diagnoses of rickets or CML, rated confidence levels, and recorded associated radiographic signs. RESULTS. Seventy children (27 girls, 43 boys) had rickets; 77 children (37 girls, 40 boys) had CML. Children with CML were younger than those with rickets (mean, 3.7 vs 14.2 months, p < .001; 89.6% vs 5.7% younger than 6 months; 3.9% vs 65.7% older than 1 year). All children with CML had injuries in addition to the knee CML identified at physical examination or other imaging examinations. Radiologists had almost perfect agreement for moderate- or high-confidence interpretations of rickets (κ = 0.92) and CML (κ = 0.89). Across radiologists, estimated sensitivity, specificity, and accuracy for CML for moderate- or high-confidence interpretations were 95.1%, 97.0%, and 96.0%. Accuracy was not significantly different between pediatric and nonpediatric radiologists (p = .20) or between less experienced and more experienced radiologists (p = .57). Loss of metaphyseal zone of provisional calcification, cupping, fraying, and physeal widening were more common in rickets than CML, being detected in less than 4% of children with CML. Corner fracture, bucket-handle fracture, subphyseal lucency, deformed corner, metaphyseal irregularity, and subperiosteal new bone formation were more common in CML than rickets, being detected in less than 4% of children with rickets. CONCLUSION. Radiologists had high interobserver agreement and high diagnostic performance for differentiating rickets and CML. Recognition that CML mostly occur in children younger than 6 months and are unusual in children older than 1 year may assist interpretation. CLINICAL IMPACT. Rickets and CML have distinct radiographic signs, and radiologists can reliably differentiate these two entities.

The effects of a periodontal ligament analogue on occlusal contact forces.

BACKGROUND: Previous bench-top studies examined the details of the mechanical environment of rigidly fixed occluding teeth. It was demonstrated that during each chomp, contacting molar teeth experience in-occlusal-plane forces (Flateral ) that are highly transient in magnitude and direction. OBJECTIVES: The objectives of this study are to identify Flateral behaviours that are attributable to the presence of a visco-elastic periodontal ligament (PDL) analogue, and to assess the necessity of incorporating it into future studies. METHODS: A weighted maxillary molar denture tooth was lowered onto, and raised from, a matching mandibular molar 10 times. The latter was supported by a load cell that continuously measured Flateral . For statistical purposes, the test was repeated with 21 (n = 21) different occlusal relationships obtained with 0.05 mm incremental shifts of the lower assembly. RESULTS: Overall, the results are similar to those of rigid attachment but the details of the Flateral profiles are very different. CONCLUSION: The PDL plays a major role in the mechanical environment of occlusion, suggesting that, in general (not necessarily always), it should be integrated into studies of occlusion.

The impact of the COVID-19 pandemic on U.S. orthodontic practices in 2020.

INTRODUCTION: This study aimed to investigate the immediate impact and long-term implications of severe acute respiratory syndrome coronavirus on orthodontic practices in the United States in 2020. METHODS: A 35-item survey was developed and validated to investigate the impact of the coronavirus disease (COVID-19) pandemic on the orthodontic specialty. The survey contained 5 domains, including respondent's demographic information, COVID-19 information acquisition, practice ramifications of the COVID-19 pandemic, financial implications of the COVID-19 pandemic, and patient management strategies during the COVID-19 pandemic. This voluntary survey acquired responses from active orthodontists in the United States. Associations of demographic and practice characteristics with items related to COVID-19 were assessed using chi-square tests, with a 5% significance level. RESULTS: The survey was disseminated to 5,694 orthodontists, and 507 complete surveys were obtained (response rate of 8.9%). Respondents indicated that they obtained the most useful information regarding the COVID-19 pandemic through professional associations and internet or online news resources. However, 30% of the orthodontists believed information regarding personal financial guidelines was lacking. Most respondents identified delayed treatment progress and temporary staff layoffs as the 2 most negative ramifications of mandated office closures. Approximately 93% of practices applied for and used some sort of stimulus funding offered through the Coronavirus Aid, Relief, and Economic Security Act. Respondents indicated that the COVID-19 related office closures resulted in an average of 50% decrease in net revenue. CONCLUSIONS: The survey found that the COVID-19 pandemic had a broad and significant impact on patient care and financial aspects of U.S. orthodontic practices in 2020. Although generally accepting of the federal and state recommendations, respondents appeared to desire more guidance during the early phase of the pandemic.

Nutritional Assessment of Denture Wearers Using Matched Electronic Dental-Health Record Data.

PURPOSE: To assess the nutritional profile of denture wearers through a retrospective cohort study using nutritional biomarkers from matched electronic dental and health record (EDR-EHR) data. MATERIALS AND METHODS: The case group (denture wearers) included matched EDR-EHR data of patients who received removable partial, complete, and implant-supported prosthodontic treatments between January 1, 2010 and December 31, 2018, study time. The control (nondenture wearers) group did not have recorded denture treatments and included patient records within 1 year of the denture index date (first date of case patients' receiving complete or partial denture) of the matching cases. The qualified patients' EDR were matched with their EHR based on the availability of laboratory reports within 2 years of receiving the dentures (index date). Nutritional biomarkers were selected from laboratory reports for complete blood count, comprehensive and basic metabolic profile, lipid, and thyroid panels. Summary statistics were performed, and general linear mixed effect models were used to evaluate the rate of change over time (slope) of nutritional biomarkers before and after the index date. Likelihood ratio tests were performed to determine the differences between dentures and controls. RESULTS: The final cohort included 10,481 matched EDR-EHR data with 3,519 denture wearers and 6,962 controls that contained laboratory results within the study time. The denture wearers' mean age was 57 ±10 years and the control group was 56 ±10 years with 55% females in both groups. Pre-post analysis among denture wearers revealed decreased serum albumin (p = 0.002), calcium (p = 0.039), creatinine (p < 0.001) during the post-index time. Hemoglobin (Hb) was higher pre-index, and was decreasing during the time period but did not change post-index (p < 0.001). Among denture wearers, completely edentulous patients had a significant decrease in serum albumin, creatinine, blood urea nitrogen (BUN), but increased estimated glomerular filtration rate (eGFR). In partially edentulous patients, total cholesterol decreased (p = 0.018) and TSH (p = 0.004), BUN (p < 0.001) increased post-index. Patients edentulous in either upper or lower arch had decreased BUN and eGFR during post-index. Compared to controls, denture wearers showed decreased serum albumin and protein (p = 0.008), serum calcium (p = 0.001), and controls showed increased Hb (p = 0.035) during post-index. CONCLUSIONS: The study results indicate nutritional biomarker variations among denture wearers suggesting a risk for undernutrition and the potential of using selected nutritional biomarkers to monitor nutritional profile.

Tooth Age Impact on Dental Erosion Susceptibility and Treatment Efficacy.

This laboratory study investigated the impact of tooth age on dental erosion susceptibility and preventive treatment efficacy. Extracted human premolars were selected and had their age estimated (∼10-100 years old) using established dental forensic methods. Enamel and root dentin slabs were prepared, embedded in acrylic blocks, flattened, and polished. The specimens were randomly assigned to one of three treatments (n = 93): Sn+F (800 ppm Sn as SnCl2 and 250 ppm F as NaF, pH 4.5), NaF (250 ppm F, pH 4.5), or deionized water (DIW). Each specimen was subjected for 10 days to a daily cycling protocol consisting of six 5-min erosive challenges (0.3% citric acid, pH 2.6), six 60-min remineralization periods (artificial saliva), and three 2-min treatments with the test solutions. Surface loss (SL) was measured after 3, 5, and 10 days, using optical profilometry. Effects of tooth age, antierosive treatment, and time on SL were evaluated using linear mixed effects regression analysis. SL increased with age for all substrate-treatment-time combinations (p < 0.0001). Sn+F and NaF solutions significantly reduced SL compared to DIW, regardless of substrate, time, or age (p < 0.0001), with best results shown for Sn+F. Efficacy of Sn+F increased with tooth age on enamel, but tooth age did not affect the efficacy of NaF on enamel. For dentin, increased efficacy was observed with age after 5 (for Sn+F) and 10 days (for Sn+F and NaF). In conclusion, increase of tooth age rendered enamel and root dentin more susceptible to dental erosion. NaF preventive efficacy improved with tooth age for dentin, in advanced erosion simulation. Sn+F reduced enamel SL due to erosion regardless of tooth age.

Objective assessment of simulated non-carious cervical lesion by tridimensional digital scanning.

OBJECTIVE: To explore the use of 3D intraoral scanner/image analysis for the detection and monitoring of simulated non-carious cervical lesions (NCCLs) in vitro. MATERIALS AND METHODS: A total of 288 NCCLs of different severities and simulated using a laboratorial model associating toothbrush stiffness (soft, medium, and hard) and toothpaste abrasivity (low, medium, high, and negative control) were analyzed. Dental impressions were taken from specimens before and after 35K and 65K brushing strokes, and then scanned with a CEREC Omnicam scanner. 3D models were analyzed for volumetric tooth loss. 3D optical profilometry was considered as the gold standard. Data were analyzed using ANOVA and Fisher's PLSD tests (alpha = 0.05), and agreement between methods by using intraclass correlation coefficient. RESULTS: Toothbrushes of hard and mid stiffness caused higher tooth loss than soft when associated with the highest abrasive, at 35K and 65K strokes (p < 0.001). Variation in slurry abrasivity led to differences in tooth loss (with control < low < medium < high, p < 0.0001) after both 35K and 65K strokes, regardless of the type of toothbrush used, except at 35K, wherein control = low (p = 0.55). 35K strokes caused less tooth loss than 65K for all abrasive slurries (p < 0.0001) except controls. The intraclass correlation coefficient for agreement between the test and gold standard methods was 0.85. CONCLUSIONS: Analysis of 3D images from intraoral scanner could detect and monitor NCCL progression, although this ability was limited on incipient lesions. Overall good agreement was found between the test method and optical profilometry. CLINICAL RELEVANCE: The suggested method may be applicable to detect and monitor NCCLs clinically.

The effect of surface treatments on the color stability of CAD-CAM interim fixed dental prostheses.

STATEMENT OF PROBLEM: Additive manufacturing or 3D printing is gaining popularity in dentistry, including for interim fixed dental prostheses (IFDPs). However, evidence regarding the color stability of 3D-printed IFDPs is lacking. PURPOSE: The purpose of this in vitro study was to investigate whether different surface treatments could affect the color stability of milled and 3D-printed IFDPs after simulated physiological aging. MATERIAL AND METHODS: Forty milled IFDPs were fabricated with a 5-axis dental mill (DWX-51D; Roland DGA Corp) from polymethyl methacrylate disks (Temp Esthetic 98, A3.5, 98.5×16 mm; Harvest Dental Products, LLC). Forty 3D-printed IFDPs were fabricated with an in-office digital light processing 3D printer (MAX; Asiga) and light-polymerizing resin (NextDent Crown & Bridge A3.5; NextDent B.V). All milled and 3D-printed IFDPs were allocated into 4 different groups (n=10), according to different surface treatments: Control, Polish, Optiglaze, and Skinglaze. In the Control group, no surface treatment was applied to the IFDPs. For the Polish group, IFDPs were finished and polished with aluminum oxide finishers/polishers (Enhance PoGo Complete Kit; Dentsply Sirona). For the Optiglaze and Skinglaze groups, specimens were first finished and polished and prepared with additional light-polymerizing protective coatings (Optiglaze; GC America Inc, or New Outline Skin Glaze; anaxdent North America). Shade measurements were recorded with a digital spectrophotometer (Vita Easyshade V; VITA North America) before and after the thermocycling for the color stability comparisons. The effects of interim prosthesis type and surface treatments on ΔE∗, ΔL∗, Δa∗, and Δb∗ were examined using 2-way analysis of variance (ANOVA), and ΔE∗ was considered as the primary outcome variable. Post hoc pairwise comparisons were performed by using the Tukey honestly significant difference (HSD) method (α=.05 for all tests). RESULTS: Milled IFDPs had significantly smaller ΔE∗ than 3D-printed prostheses for the Control group only (P<.001). Within the milled IFDPs, Optiglaze group (mean ±standard deviation, 1.01 ±0.38) had significantly lower ΔE∗ than all the other surface treatments groups (Control group: 2.38 ±0.44, P<.001; Polish group: 1.83 ±0.51, P=.025; and Skinglaze group: 1.85 ±0.78, P=.021). Within the 3D-printed IFDPs, the Control group (3.83 ±0.71) had significantly larger ΔE∗ than all other surface treatments (Polish group: 2.66 ±0.89, P=.018; Skinglaze group: 1.40 ±0.73, P<.001; and Optiglaze group: 1.37 ±0.67, P<.001). The Polish group had significantly higher ΔE∗ than Skinglaze group (P=.009) and Optiglaze group (P=.007), while Skinglaze and Optiglaze groups were not significantly different from each other (P=1.000). CONCLUSIONS: For the milled IFDPs, only the nano-filled, light-polymerizing protective coating significantly lowered color changes after thermocycling simulating 6 months of intraoral physiological aging. For the 3D-printed IFDPs, surface polishing and both light-polymerizing protective coating agents all significantly reduced color changes of the prostheses after thermocycling. The protective effect of light-polymerizing coating agents was more substantial.

Susceptibility of Dental Enamel of Different Ages to Caries-Like Lesion Development.

This study investigated the impact of estimated age, anatomical location, and the presence of wear facets on the susceptibility of enamel to develop caries-like lesions. Extracted human premolars (n = 261) had their age estimated between 10 and 93 years old, using established forensic methods. Specimens of enamel (4 × 4 mm) were prepared from the middle of the buccal surfaces, preserving the outer surface layer. The central area of the block (4 × 1 mm) was protected with nail polish and used as an internal control. The specimens were demineralized for 8 days (with 0.1 M acetic acid, 1.28 mM Ca, 0.74 mM Pi, and 0.03 µg F/mL, pH 5.0), to simulate caries-like lesion development. They were then scanned individually using microtomography, and digital 2D images were used to calculate the outcomes of integrated mineral concentration loss (ΔZ in µm/g/cm3) and lesion depth (LD in µm) at 3 locations, i.e., the cervical, middle, and occlusal thirds. The presence of natural surface wear facets was considered in the analysis. Data were evaluated using a linear mixed-effects models (α = 0.05). ΔZ increased significantly as a function of estimated tooth age at all 3 locations, and this increase was greater after the age of 30 years (p < 0.001), when a higher ΔZ was found in the occlusal third than in the middle and cervical thirds (p < 0.001). LD increased only in the occlusal third before the age of 30 years (p = 0.039) and this increase was significantly greater after 30 years at all 3 locations (p < 0.01), with no differences among them (p > 0.15). The presence of wear facets significantly increased ΔZ and LD (p < 0.001 for both). Overall, we concluded that the susceptibility of enamel to developing caries-like lesions increased with estimated dental age. This effect was more pronounced after the estimated age of 30 years and in the presence of natural tooth wear facets.

The Impact of Nicotine and Cigarette Smoke Condensate on Metabolic Activity and Biofilm Formation of Candida albicans on Acrylic Denture Material.

PURPOSE: Smokers have increased denture stomatitis caused primarily by Candida albicans. The primary aim of this study was to demonstrate the impact of a wide range of nicotine and cigarette smoke condensate (CSC) concentrations on biofilm formation and metabolic activity of C. albicans on acrylic denture material. MATERIALS AND METHODS: C. albicans (ATCC strain 10231) was used. Standardized denture acrylic (PMMA) specimens (total of 135 specimens) were incubated with C. albicans and exposed to nicotine and CSC at different concentrations (0, 0.25, 0.5, 1, 2, 4, 8, 16, and 32 mg/ml) and (0, 0.25, 0.5, 1, 2, and 4 mg/ml), respectively. For each experiment, 3 samples per nicotine and CSC concentration and a total of 45 specimens (27 specimens for the nicotine and 18 specimens for the CSC-treated samples) were used and were selected randomly for each group. The control group consisted of 0 mg/ml of nicotine or CSC. The viability of C. albicans was measured using spiral plating on blood agar plates. The effect of nicotine and CSC concentrations on planktonic cells was were measured using a microplate reader. Metabolic activity of 24-hour-old established C. albicans biofilm exposed to nicotine and CSC for 24 hours in microtiter plates was determined using a 2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-carboxanilide (XTT) reduction assay. RESULTS: The viability of C. albicans increased concomitant with increasing concentrations of CSC and nicotine, particularly at 0.5 and 2 mg/ml, respectively. Concentrations of CSC and nicotine above this resulted in an inhibitory effect on C. albicans viability. CSC and nicotine at 4 and 16 mg/ml, respectively, increased C. albicans biofilm metabolic activity. CONCLUSION: Nicotine and CSC up to certain concentrations caused increases in biofilm formation, metabolic activity, viability, and planktonic cell absorbance of C. albicans. This in vitro study demonstrates the effectiveness of tobacco on promoting the growth of C. albicans and suggests their potential contributing factor in C. albicans biofilm related infections in smokers.

Regulation of articular chondrocyte catabolic genes by growth factor interaction.

Osteoarthritis is characterized by a loss of articular cartilage homeostasis in which degradation exceeds formation. Several growth factors have been shown to promote cartilage formation by augmenting articular chondrocyte anabolic activity. This study tests the hypothesis that such growth factors also play an anticatabolic role. We transferred individual or combinations of the genes encoding insulin-like growth factor-I, bone morphogenetic protein-2, bone morphogenetic protein-7, transforming growth factor-ß1, and fibroblast growth factor-2, into adult bovine articular chondrocytes and measured the expression of catabolic marker genes encoding A disintegrin and metalloproteinase with thrombospondin motifs-4 and -5, matrix metalloproteinases-3 and -13, and interleukin-6. When delivered individually, or in combination, these growth factor transgenes differentially regulated the direction, magnitude, and time course of expression of the catabolic marker genes. In concert, the growth factor transgenes regulated the marker genes in an interactive fashion that ranged from synergistic inhibition to synergistic stimulation. Synergistic stimulation prevailed over synergistic inhibition, reaching maxima of 15.2- and 2.7-fold, respectively. Neither the magnitude nor the time course of the effect of the transgene combinations could be predicted on the basis of the individual transgene effects. With few exceptions, the data contradict our hypothesis. The results demonstrate that growth factors that are traditionally viewed as chondrogenic tend also to promote catabolic gene expression. The competing actions of these potential therapeutic agents add an additional level of complexity to the selection of regulatory factors for restoring articular cartilage homeostasis or promoting repair.

Defining adenoma detection rate benchmarks in average-risk male veterans.

BACKGROUND AND AIMS: Veterans have higher prevalence of colorectal neoplasia than non-veterans; however, it is not known whether specific Veterans Affairs (VA) adenoma detection rate (ADR) benchmarks are required. We compared ADRs of a group of endoscopists for colonoscopies performed at a VA center with their ADRs at a non-VA academic medical center. METHODS: This was a retrospective review of screening colonoscopies performed by endoscopists who practice at the Indianapolis VA and Indiana University (IU). Patients were average-risk men aged 50 years or older. ADR, proximal ADR, advanced ADR, and adenomas per colonoscopy were compared between IU and the VA groups. RESULTS: Six endoscopists performed screening colonoscopies at both locations during the study period (470 at IU vs 608 at the VA). The overall ADR was not significantly different between IU and the VA (58% vs 61%; P = .21). Advanced neoplasia detection rate (13% vs 17%; P = .46), proximal ADR (46% vs 47%; P = .31), and adenomas per colonoscopy (1.59 vs 1.84; P = .24) were not significantly different. There were no significant differences in cecal intubation rate (100% vs 99%; P = .13) or withdrawal time (10.9 vs 11.1 min; P = .28). In regression analysis, there was significant correlation between the attending-specific ADRs at IU and the VA (P = .041, r2 = 0.69). CONCLUSIONS: In this study of average-risk men undergoing screening colonoscopies by the same group of endoscopists, the ADRs of VA and non-VA colonoscopies were not significantly different. This suggests that a VA-specific ADR target is not required for endoscopists with high ADRs.

SIC-8000 versus hetastarch as a submucosal injection fluid for EMR: a randomized controlled trial.

BACKGROUND AND AIMS: Viscous solutions provide a superior submucosal cushion for EMR. SIC-8000 (Eleview; Aries Pharmaceuticals, La Jolla, Calif) is a commercially available U.S. Food and Drug Administration-approved solution, but hetastarch is also advocated. We performed a randomized trial comparing SIC-8000 with hetastarch as submucosal injection agents for colorectal EMR. METHODS: This was a single-center, double-blinded, randomized controlled trial performed at a tertiary referral center. Patients were referred to our center with flat or sessile lesions measuring ≥15 mm in size. The primary outcome measures were the Sydney resection quotient (SRQ) and the rate of en bloc resections. Secondary outcomes were total volume needed for a sufficient lift, number of resected pieces, and adverse events. RESULTS: There were 158 patients with 159 adenomas (SIC-8000, 84; hetastarch, 75) and 57 serrated lesions (SIC-8000, 30; hetastarch, 27). SRQ was significantly better in the SIC-8000 group compared with hetastarch group (9.3 vs 8.1, P = .001). There was no difference in the proportion of lesions with en bloc resections. The total volume of injectate was significantly lower with SIC-8000 (14.8 mL vs 20.6 mL, P = .038). CONCLUSIONS: SIC-8000 is superior to hetastarch for use during EMR in terms of SRQ and total volume needed, although the absolute differences were small. (Clinical trial registration number: NCT03350217.).

A Comparison of Simple Analytical Methods for Determination of Fluoride in Microlitre-Volume Plasma Samples.

The aim was to compare potential methods for fluoride analysis in microlitre-volume plasma samples containing nano-gram amounts of fluoride. Methods: A group of 4 laboratories analysed a set of standardised biological samples as well as plasma to determine fluoride concentration using 3 methods. In Phase-1, fluoride analysis was carried out using the established hexamethyldisiloxane (HMDS)-diffusion method (1 mL-aliquot/analysis) to obtain preliminary measurement of agreement between the laboratories. In Phase-2, the laboratories analysed the same samples using a micro-diffusion method and known-addition technique with 200 µL-aliquot/analysis. Coefficients of Variation (CVs) and intra-class correlation coefficients (ICCs) were estimated using analysis of variance to evaluate the amount of variation within- and between-laboratories. Based on the results of the Phase-2 analysis, 20 human plasma samples were analysed and compared using the HMDS-diffusion method and known-addition technique in Phase-3. Results: Comparison of Phase-1 results showed no statistically significant difference among the laboratories for the overall data set. The mean between- and within-laboratory CVs and ICCs were < 0.13 and ≥0.99, respectively, indicating very low variability and excellent reliability. In Phase-2, the overall results for between-laboratory variability showed a poor CV (1.16) and ICC (0.44) for the micro-diffusion method, whereas with the known-addition technique the corresponding values were 0.49 and 0.83. Phase-3 results showed no statistically significant difference in fluoride concentrations of the plasma samples measured with HMDS-diffusion method and known- addition technique, with a mean (SE) difference of 0.002 (0.003) µg/mL. In conclusion, the known-addition technique could be a suitable alternative for the measurement of fluoride in plasma with microlitre-volume samples.

Polymerization pattern characterization within a resin-based composite cured using different curing units at two distances.

OBJECTIVES: To investigate the relationship of the irradiance-beam-profile areas from six different light-curing units (LCUs) with the degree of conversion (DC), microhardness (KH), and cross-link density (CLD) throughout a resin-based composite (RBC) cured at two clinically relevant distances, and to explore the correlations among them. MATERIALS AND METHODS: A mapping approach was used to measure DC using micro-Raman spectroscopy, KH using a Knoop indentor on a hardness tester, and %KH reduction after ethanol exposure, as an indicator for CLD within a nano-hybrid RBC increment (n = 3) at various depths. These sample composites were cured from two distances while maintaining the radiant exposure, using six different light-curing units: one quartz-tungsten-halogen; two single and three multiple-emission-peak light-emitting-diode units. Irradiance beam profiles were generated for each LCU at both distances, and localized irradiance values were calculated. Points across each depth were analyzed using repeated measures ANOVA. Correlations across multiple specimen locations and associations between beam uniformity corresponding with polymerization measurements were calculated using linear mixed models and Pearson correlation coefficients. RESULTS: Significant non-uniform polymerization patterns occurred within the specimens at various locations and depths. At 2-mm curing distance, the localized DC = 52.7-76.8%, KH = 39.0-66.7 kg/mm2, and %KH reduction = 26.7-57.9%. At 8-mm curing distance, the localized DC = 50.4-78.6%, KH = 40.3-73.7 kg/mm2, and %KH reduction = 28.2-56.8%. The localized irradiance values were weakly correlated with the corresponding DC, KH, and %KH reduction, with only a few significant correlations (p < 0.05). CONCLUSIONS: Although significant differences were observed at each depth within the specimens, the localized irradiance values for all LCUs did not reflect the polymerization pattern and did not seem to have a major influence on polymerization patterns within the RBC, regardless of the curing distance. CLINICAL RELEVANCE: Commonly used LCUs do not produce uniform polymerization regardless of the curing distance, which may contribute to the risk of RBC fracture.

Bleaching of simulated stained-remineralized caries lesions in vitro.

OBJECTIVE: Non-invasive esthetic treatment options for stained arrested caries lesions have not been explored. This study aimed to develop laboratory models to create stained-remineralized caries-like lesions (s-RCLs) and to test the efficacy of bleaching on their esthetic treatment. MATERIALS AND METHODS: One hundred twelve enamel/dentin specimens were prepared from human molars, embedded, and had their color measured spectrophotometrically at baseline and after demineralization. They were randomly divided into four groups (n = 14) based on the staining/remineralization protocols for a total of 5 days: G1, no staining/no remineralization; G2, no staining/remineralization in artificial saliva (AS); G3, non-metallic staining/remineralization with sodium fluoride/AS; and G4, metallic staining/remineralization with silver diamine fluoride/AS. The lesion mineral loss (ΔZ) and depth (L) were measured using transverse microradiography along with color change (ΔE). Specimens were bleached and color was re-evaluated. Data were analyzed using ANOVA models followed by Fisher's PLSD tests (α = 0.05). RESULTS: s-RCLs in G4 were significantly (p < 0.001) darker than G3, G2, and G1 regardless of substrate type and condition. s-RCLs in G2, G3, and G4 showed significantly lower ΔZ and L than G1 (all p < 0.001), confirming occurrence of remineralization. G4 exhibited significantly lower ΔZ and L compared to G2 (p < 0.001). Bleaching was more effective in non-metallic than in metallic stained lesions regardless of substrate type (p < 0.001). CONCLUSION: The proposed models created distinct s-RCLs. Non-metallic s-RCLs were lighter and more responsive to bleaching compared to metallic s-RCLs. CLINICAL RELEVANCE: The developed experimental models allow the further investigation of the efficacy and safety of different clinical strategies for the esthetic management of s-RCLs.

Interplay between toothbrush stiffness and dentifrice abrasivity on the development of non-carious cervical lesions.

OBJECTIVE: This study investigated the effect of toothbrush stiffness and dentifrice slurry abrasivity on the development and progression of simulated non-carious cervical lesions (NCCLs). MATERIALS AND METHODS: Human maxillary premolars were allocated to 12 groups generated by the association between toothbrushes, soft, medium, and hard stiffness, and simulated dentifrice slurries, lower, medium, and higher; deionized water (DI) served as negative control. Teeth were mounted on acrylic blocks, and their root surfaces partially covered with acrylic resin to simulate gingiva, leaving a 2-mm area apical to the cemento-enamel junction exposed to toothbrushing. Specimens were brushed with the test slurries for 35,000 and 65,000 double strokes. Impressions taken at baseline and after both brushing periods were scanned by a 3D optical profilometer. Dentin volume loss (mm3) was calculated by image subtraction. Data were analyzed using three-way ANOVA and Fisher's PLSD tests. RESULTS: All toothbrushes caused higher volume loss when associated to higher abrasive slurry, compared to medium- and lower-abrasive slurries. Medium caused more volume loss than lower-abrasive slurry, which led to more volume loss than DI. Hard and medium toothbrushes were not different when used with medium- or higher-abrasive slurries. There were no differences among toothbrushes when used with DI and lower-abrasive slurry. Overall, 35,000 brushing strokes resulted in significantly less volume loss than 65,000. CONCLUSIONS: Toothbrush stiffness was an important factor on NCCL development, especially when brushing with medium- and higher-abrasive slurries. CLINICAL RELEVANCE: Medium and hard toothbrushes associated with medium- and high-abrasive toothpastes can yield more severe NCCLs.

Accuracy, reproducibility, and dimensional stability of additively manufactured surgical templates.

STATEMENT OF PROBLEM: Additively manufactured surgical templates are commonly used for computer-guided implant placement. However, their accuracy, reproducibility, and dimensional stability have not been thoroughly investigated with the different 3D printers and materials used for their fabrication. PURPOSE: The purpose of this in vitro study was to evaluate the accuracy, reproducibility, and dimensional stability of additively manufactured surgical templates fabricated by using different 3D printers. MATERIAL AND METHODS: Thirty surgical templates were designed and additively manufactured from 3 different 3D printers as follows: group SLA (n=10) was fabricated by using a desktop stereolithography (SLA) 3D printer and photopolymerizing resin; group PolyJet (n=10) was fabricated by using a PolyJet 3D printer and photopolymerizing resins; and group DMP (n=10) was fabricated by using a direct metal printing (DMP) system and Co-Cr metal alloy. All surgical templates were scanned by using a laser scanner within 36 hours of production and digitalized again 1 month later. All scanned files were compared with the corresponding designed files in a surface matching software program. The mean deviation root mean square (RMS, measured in mm, representing accuracy), percentage of measurement data points within 1 standard deviation of mean RMS (in %, representing reproducibility), and dimensional changes were determined and compared. RESULTS: At the postproduction stage, group PolyJet was most accurate with the lowest RMS value of 0.10 ±0.02 mm and highest reproducibility with 93.07 ±1.54% of measurement data points within 1 standard deviation of mean RMS. After 1-month storage, group PolyJet(1month) remained the most accurate with the lowest RMS value of 0.14 ±0.03 mm and the highest reproducibility value of 92.46 ±1.50%. For dimensional stability, group SLA versus group SLA(1month) comparison showed a significant decrease in accuracy (RMS values of 0.20 ±0.08 mm versus 0.25 ±0.08 mm, P<.001) and reproducibility (88.16 ±3.66% versus 86.10 ±4.16%, P=.012). Group PolyJet versus group PolyJet(1month) comparison only showed significant changes in accuracy (RMS values of 0.10 ±0.02 mm versus 0.14 ±0.03 mm, P=.011). Group DMP versus group DMP(1month) comparison showed no significant changes in accuracy (RMS values of 0.19 ±0.03 mm versus 0.20 ±0.04 mm, P=.981) or reproducibility (89.77 ±1.61% versus 89.74 ±2.24%, P=1.000). CONCLUSIONS: Printed resin surgical templates produced by using the PolyJet 3D printer showed higher accuracy and reproducibility than those produced by using the desktop SLA 3D printer and printed Co-Cr surgical templates at both the postproduction stage and after 1-month storage. The level of accuracy and reproducibility in printed Co-Cr surgical templates was not affected by 1-month storage.