Surveillance of PFAS in sludge and biosolids at 12 water resource recovery facilities.

Per- and polyfluoroalkyl substances (PFAS) are refractory anthropogenic chemicals and current treatment processes at municipal water resource recovery facilities (WRRFs) cannot efficiently degrade them, hence, these chemicals cycle through the environment. Certain PFAS can be concentrated in biosolids from WRRFs and are commonly land applied for beneficial reuse. Given recent advances in measurement of PFAS, documentation of the range of concentrations in pre-stabilized sludge and stabilized biosolids is critical to evaluating treatment best practices and assessing potential human health and ecological risks. In this study, pre-stabilized sludge and post-stabilized biosolids samples were collected from 12 major WRRFs across the United States. PFAS were analyzed using Environmental Protection Agency (EPA) Method SW846-3500C/537.1, and Draft EPA Method 1633, by one commercial laboratory and two university research laboratories, respectively. Results comparison among laboratories demonstrated statistical differences in PFAS concentrations among split samples. For example, 5:3 FTCA (fluorotelomer carboxylic acid) concentrations in post-stabilized sludge at Lab 1 were measured at 21 ng/g (dry), while they were detected at 151 ng/g (dry) in Lab 3. Further, higher PFAS concentrations were observed in post-stabilized biosolids compared to pre-stabilized sludges, regardless of the laboratory or analysis method, even when solids destruction through solids stabilization was considered. Further research is required to refine methods for analyses of PFAS in sludge and biosolids samples from WRRFs prior to being used for development of regulatory actions as well as understanding how various treatment protocols could impact concentrations of PFAS in land-applied biosolids.

Multi-laser nanoparticle tracking analysis (NTA): A unique method to visualize dynamic (shear) and dynamic (Brownian motion) light scattering and quantify nonliving natural organic matter (NNOM) in environmental water.

Application of simultaneous multi-laser nanoparticle tracking analysis (NTA) to environmental water samples to investigate nonliving natural organic matter (NNOM) is introduced as an innovative method for observing particles directly in their native media. Multi-laser NTA results of particle visualization, particle number concentration, and particle size distribution elucidated particle dynamics in low and high total dissolved solids (TDS) aqueous environmental samples. A pond water sample and concentrate from a reverse osmosis (RO) treatment process (Stage 1) had 1.3 × 108 and 5.62 × 1019 particles/mL, respectively, (at time = 0) after filtration at 0.45 µm. Beyond the traditional applications for this instrument, this research presents novel evidence-based investigations that probe the existence of supramolecular structures in environmental waters during turbulence or quiescence. The pond water sample exhibited time-dependent aggregation as the volume distribution shifted to greater diameter during quiescence, compared to turbulence. Disaggregation (increased numbers of particles over time) was noted in the >250 nm to <600 nm region, and aggregation of >450 nm particles was also noted in the quiescent RO concentrate sample, indicative of depletion of small particles to form larger ones. Multi-laser NTA and dynamic light scattering (DLS) capabilities were compared and contrasted. DLS and NTA are different (complementary) particle sizing techniques. DLS yielded more information about the physical hydrogel in the NNOM hierarchy whereas multi-laser NTA better characterized meta-chemical and chemical hydrogel characteristics. Operationalization of innovation-moving from fundamental investigations to application-is supported by implementing novel analytical instrumentation as we address issues involving climate change, drought, and the scarcity of potable water. Multi-laser NTA can be used as a tool to study and optimize complex water and wastewater treatment processes. Questions about water treatment efficiencies, membrane fouling, assistance of pollutant transport, and carbon capture cycles affected by NNOM will benefit from insights from multi-laser NTA.

Microleakage of Silver-Modified Atraumatic Restorative Technique (SMART) Restorations Using Silver Diammine Fluoride and High-Viscosity Glass Ionomer.

Purpose: The purpose of this study was to investigate the microleakage of atraumatic glass ionomer restorations with and without silver diammine fluoride (SDF) application. Restorations with SDF are termed silver-modified atraumatic restorations (SMART). Methods: Sixty carious extracted permanent teeth were randomly allocated to two SMART groups and two control groups (n equals 15 per group) for a total of four groups. After selective caries removal, test specimens were treated with 38 percent SDF and polyacrylic acid conditioner was applied and rinsed; teeth were restored with Fuji IX GP® glass ionomer (n equals 15) or with SMART Advantage™ glass ionomer (SAGI; n equals 15). For control groups, specimens were restored with their respective GI material after selective caries removal, both without SDF. Restored teeth were placed in Dulbecco's Phosphate-Buffered Saline solution at 37 degrees Celsius for 24 hours. Teeth were thermocycled between five and 55 degrees Celsius for 1,000 cycles, stained with two percent basic fuchsin, sectioned, and visually inspected for microleakage utilizing stereomicroscopy on a four-point scale. Data were statistically analyzed using Kruskal-Wallis one-way analysis of variance on ranks using Dunn's method (P<0.05). Results: Microleakage between the two SMART restoration groups was insignificant. SAGI alone demonstrated significantly more microleakage than all other groups. There was no statistical significance between the Fuji IX GP® control group and the two SMART restoration groups. Conclusions: This in vitro study indicated that silver diammine fluoride placed before glass ionomer restoration does not increase microleakage. Polyacrylic acid may be used after SDF placement without increasing microleakage.

CT and MR Appearance of Teeth: Analysis of Anatomy and Embryology and Implications for Disease.

Abnormalities of dental development and anatomy may suggest the presence of congenital or acquired anomalies. The detection of abnormalities, therefore, is an important skill for radiologists to achieve. Knowledge of dental embryology and an understanding of the radiologic appearances of teeth at various stages of maturation are required for the appreciation of abnormal dental development. While many tooth abnormalities are well-depicted on dedicated dental radiographs, the first encounter with a dental anomaly may be by a radiologist on a computed tomographic (CT) or magnetic resonance (MR) exam performed for other reasons. This article depicts normal dental anatomy and development, describing the appearance of the neonatal dentition on CT and MRI, the modalities most often encountered by clinical radiologists. The radiology and dental literature are reviewed, and key concepts are illustrated with supplemental cases from our institution. The value of knowledge of dental development is investigated using the analysis of consecutive MR brain examinations. Finally, the anatomical principles are applied to the diagnosis of odontogenic infection on CT. Through analysis of the literature and case data, the contrast of dental pathology with normal anatomy and development facilitates the detection and characterization of both congenital and acquired dental disease.

Fate of perfluoroalkyl and polyfluoroalkyl substances (PFAS) through two full-scale wastewater sludge incinerators.

Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are an emerging issue in wastewater treatment. High-temperature thermal processes, incineration being time-tested, offer the opportunity to destroy and change the composition of PFAS. The fate of PFAS has been documented through wastewater sludge incinerators, including a multiple hearth furnace (MHF) and a fluidized bed furnace (FBF). The dewatered wastewater sludge feedstock averaged 247- and 1280-µmol targeted PFAS per sample run in MHF and FBF feed, respectively. Stack emissions (reportable for all targeted PFAS from MHF only) averaged 5% of that value with shorter alkyl chain compounds comprising the majority of the targeted PFAS. Wet scrubber water streams accumulated nonpolar fluorinated organics from the furnace exhaust with an average of 0.740- and 0.114-mol F- per sample run, for the MHF and FBF, respectively. Simple alkane PFAS measured at the stack represented 0.5%-4.5% of the total estimated facility greenhouse gas emissions. PRACTITIONER POINTS: The MHF emitted six short chain PFAS from the stack, which were shorter alkyl chain compounds compared with sludge PFAS. The FBF did not consistently emit reportable PFAS from the stack, but contamination complicated the assessment. Five percent of the MHF sludge molar PFAS load was reported in the stack. MHF and FBF wet scrubber water streams accumulated nonpolar fluorinated organics from the furnace exhaust. Ultra-short volatile alkane PFAS measured at the stack represented 0.5%-4.5% of the estimated facility greenhouse gas emissions.

Nonpharmacological Behavior Guidance for the Pediatric Dental Patient.

Purpose: To present evidence-based recommendations on nonpharmacological behavior guidance for the pediatric dental patient. Methods: The work group assessed eight systematic reviews for effectiveness of nonpharmacological behavior guidance techniques in children undergoing preventive care or a dental treatment visit. The key outcomes assessed included cooperative behavior, anxiety, and procedural pain. To formulate the recommendations, the work group used the GRADE framework to obtain consensus on domains such as priority of the problem, certainty of the evidence, balance between desirable and undesirable consequences, patients' values and preferences, acceptability, and feasibility. Results: Overall, the use of basic nonpharmacological behavior guidance techniques resulted in trivial-to-small effect on improvement in behavior or reduction in anxiety. However, for children and adolescents undergoing preventive care, mobile applications and modeling showed large effects in reduction of anxiety. For those undergoing dental treatment, strategies such as modeling, positive reinforcement, biofeedback relaxation, breathing relaxation, animal-assisted therapy, combined tell-show-do, audiovisual distraction, and cognitive behavior therapy showed large reduction in anxiety. For children and adolescents with special health care needs, audiovisual distraction and sensory-adapted dental environment showed large reduction of anxiety. Conclusions: All the formulated recommendations were conditional and were mostly based on very low certainty of evidence. Conditional recommendations imply that different choices or combinations of behavior guidance techniques may be most appropriate for different patients. Clinicians should use techniques consistent with the parent/patient values and preferences. These recommendations are based on the best available evidence to-date and are intended to aid clinical decision making.

A Structural Analysis of 3D Printed Pediatric Space Maintainers.

Purpose: To design, fabricate, and evaluate in vitro 3D printed space maintainers (SMs) and compare their retentive capabilities to tradi- tional stainless-steel (SS) space maintainers. Methods: E-Guard was selected as the printing material based on flexural strength and elastic modulus. SMs with a claw design were printed, cemented to testing blocks, and vertically loaded to determine failure strength and flexure (n equals 10). The intaglio surfaces of SM bands, printed with plain, crosshatched, or horizontal ridges, were cemented to extracted primary teeth. The force needed to dislodge the bands was compared to cemented traditional SS bands (n equals 14). Results: Flexural strength (mean±standard deviation [SD]) of E-Guide, E-Dent, and E-Guard materials was 65±12, 90±13, 134±25 MPa, respectively. Elastic modulus (mean±SD) was 1.54±0.40, 2.49±0.14, 2.65±0.89 GPa, respectively. When subjected to vertical loading, the mean failure load of 3D printed SMs (E-Guard) was 124 N and the mean deflection at fracture was 1.73 mm. Retention strengths (mean±SD) of 3D printed bands were 32±13, 43±13, 43±16 N for the plain printed, cross- hatched, and horizontal ridges designs, respectively. The retention strength of traditional SS bands was 126±27 N. Conclusions: E-Guard had superior mechanical properties among tested printing resins. Strength and deflection under the vertical load of claw-design 3D printed space maintainers may be adequate as a viable alternative to traditional SMs. Retention of 3D printed SMs was significantly lower than for traditional SS bands. Textured intaglio surfaces did not significantly improve the retention of 3D printed bands.

Nonpharmacological Behavior Guidance For Children During Dental Treatment Visits: A Systematic Review and Meta-Analysis-Part 2.

'Purpose: To assess the effectiveness of nonpharmacological behavior guidance interventions used for children undergoing dental treatment visits. METHODS: Databases: Ovid MEDLINE, PsycINFO (EBSCOhost), Embase, and Cochrane Library, were searched from 1946 to February 2022, for randomized clinical trials (RCTs) comparing effectiveness of basic and advanced nonpharmacological techniques rendered during a dental treatment visit including sealants, restorative care, dental local anesthesia, and simple surgical procedures. The primary outcome measures were reduction in anxiety, fear, pain, and improvement in cooperative behavior. Eight authors determined the included RCTs, performed data extraction, and assessed the risk of bias (ROB). Standardized Mean Difference calculation and assignment of quality of evidence by Grading of Recommenda- tions Assessment, Development and Evaluation approach were done. RESULTS: Forty articles qualified for analysis from 219 screened articles. Included studies evaluated the effectiveness of pre-visit preparation and in office strategies rendered pre-/post- or during treatment such as positive imagery, direct observation/modeling, desensitization, tell-show-do and its modifications, voice control, positive reinforcement, memory restructuring, bio- feedback and breathing relaxation, animal assisted therapy, combined therapies, and cognitive behavior therapy. The certainty of evidence ranged from Very low to high and the magnitude of effect varied from trivial to large change in the desired outcomes. CONCLUSIONS: Most of the basic non- pharmacological behavior guidance techniques showed trivial to small reduction in self-reported anxiety and/or improvement in behavior, with modeling, positive reinforcement, biofeedback relaxation, breathing relaxation, animal assisted therapy, combined tell-show-do and audiovisual distraction, and cognitive behavior therapy showing large effects in reduction of anxiety based on some scales.

Nonpharmacological Behavior Guidance for Children with Special Health Care Needs During Preventive and Treatment Dental Visits: A Systematic Review-Part 3.

PURPOSE: To assess the effectiveness of nonpharmacological behavior guidance interventions used for children and youth with special health care needs (CYSHCN) during preventive and dental treatment visits. METHODS: Databases: Ovid MEDLINE, PsycINFO (EBSCOhost), Embase, and Cochrane Library, were searched from 1946 to February 2022, for randomized clinical trials (RCTs) comparing effectiveness of basic and advanced nonpharmacological techniques rendered during a preventive visit (exam, fluoride application, radiographs, and prophylaxis) or a treat- ment visit (simple surgical treatment, sealants, restorative care with or with local anesthesia) with control or other interventions. The primary outcome measures for the studied interventions were reduction in anxiety, fear, pain, and improvement in cooperative behavior. Eight authors determined the included Randomized Controlled Trials (RCTs), performed data extraction, and assessed the risk of bias (ROB). Standardized Mean Difference calculation and assignment of quality of evidence by Grading of Recommendations Assessment, Development and Evaluation approach were done. RESULTS: Eleven articles qualified for analysis from 219 screened articles. Included studies evaluate the effectiveness of in office strategies such as modeling, audio-visual distraction, sensory adapted dental environment, and picture exchange communication system. The certainty of evidence ranged from Very low to Low and the magnitude of effect varied from trivial to large change in the desired outcomes. CONCLUSIONS: Most basic non-pharmacological behavior guidance techniques showed some trivial to small reduction in self-reported anxiety and/ or improvement in behavior, with audiovisual distraction, Sensory Adapted Dental Environment, and Picture Exchange Communication System showing large reduction in anxiety based on some rating scales. Systematic Review Registration Number: PROSPERO: CRD42022314723.

Nonpharmacological Behavior Guidance for Children During Preventive Dental Visits: A Systematic Review-Part 1.

PURPOSE: To assess the effectiveness of nonpharmacological behavior guidance interventions used for a child undergoing preventive dental visits. METHODS: Databases: Ovid MEDLINE, PsycINFO (EBSCOhost), Embase, and Cochrane Library, were searched from 1946 to February 2022, for randomized clinical trials (RCTs) comparing effectiveness of basic and advanced nonpharmacological techniques rendered during a pre- ventive visit including examination, prophylaxis, fluoride application and radiographs. Workgroup (WG) identified moderate-to-high quality system- atic reviews (SRs) published on hypnosis, audiovisual distraction, and parental presence/ absence; and decided to exclude these interventions from current SR to avoid duplication. The primary outcome measures for the studied interventions included reduction in anxiety, fear, pain, and improve- ment in cooperative behavior. Eight authors determined the included RCTs, performed data extraction, and assessed the risk of bias. Standardized Mean Difference calculation and assignment of quality of evidence by Grading of Recommendations Assessment, Development and Evaluation approach were done. RESULTS: Fifteen articles qualified for analysis from 219 screened articles. WG found studies evaluating effectiveness of pre- visit preparation and in-office strategies rendered pre- or during treatment such as positive imagery, communication, modeling, tell-show-do, magic tricks, mobile applications, positive reinforcement, and sensory adapted dental environment. The certainty of evidence ranged from Very low to Moderate and the magnitude of effect varied from trivial to a large change in the desired outcomes. CONCLUSIONS: Most basic nonpharmacological behavior guidance techniques showed trivial to small reduction in self-reported anxiety and/or improvement in behavior, with mobile application and modeling showing large effects in reduction of anxiety based on some rating scales. Systematic Review Registration Number: PROSPERO: CRD42022314723.

Transformation of organic carbon through medium pressure (polychromatic) UV disinfection of wastewater effluent during wet weather events.

An observed decrease in total organic carbon (TOC) and dissolved organic carbon (DOC) concentrations following wastewater disinfection with medium pressure (MP, polychromatic) ultraviolet (UV) irradiation during wet weather flows is investigated. When antecedent rainfall in the previous 7-days was >2 in (5 cm), TOC and DOC concentrations decreased dramatically following MP-UV disinfection. Organic carbon surrogate measurements of biological oxygen demand (BOD), TOC, DOC, turbidity, UVA - 254 nm, SUVA (specific UVA), scanning UV-Visible spectra (200-600 nm), fluorescence excitation-emission matrix (EEM) spectra, and light scattering data are presented for wastewater resource recovery facility (WRRF) influent, secondary effluent (pre-UV-disinfection), and MP-UV-disinfected (final effluent) samples. TOC and DOC in wastewater influent and secondary effluent (i.e., pre-UV disinfection) correlated with antecedent rainfall conditions. The percent TOC and DOC removal through secondary treatment (i.e., from influent to effluent pre-UV) and the percent TOC and DOC removal through MP-UV disinfection (i.e., from effluent pre-UV to effluent post-UV) were compared and the latter approached 90 % through MP-UV disinfection during high antecedent rainfall conditions. Spectroscopy (UV, visible, or fluorescence) was performed on samples after filtration through 0.45 µm filters, i.e., the operationally defined DOC fraction of aquatic carbon. Scanning UV-visible spectra indicated transformation of an unidentified wastewater component into light-scattering entities regardless of antecedent rainfall conditions. The types of organic carbon (diagenetic, biogenic, or anthropogenic) and the significance of wet weather are discussed. An organic carbon contribution via infiltration and inflow was attributed as a source-of-interest in this research.

Benefits of virtual externships with a pediatric dentistry program for potential residents.

PURPOSE: To determine if a virtual externship (VE) is beneficial to potential applicants regarding their perceived knowledge of a pediatric dentistry residency program. Secondarily, this study identified general program characteristics that influence resident ranking decisions. METHODS: All applicants who applied to a pediatric dentistry residency program in the Southeast were invited to participate in a VE. Those who participated in the externship (n = 65) were asked to voluntarily complete Pre- and Post-VE surveys. Participants were asked 22 questions about their level of knowledge of both tangible and intangible aspects of the program such as stipend, patient volume, faculty-resident interaction, and resident comradery. Participants were also asked to rank 9 general characteristics that influence ranking decisions such as geography, cost to attend, and reputation of the program and were asked to rate their satisfaction with the VE. Post-VE data were compared to pre-VE data to determine level of knowledge gained via Wilcoxin matched pairs signed rank test (significance set at p < 0.05). RESULTS: When comparing Pre- and Post-VE ratings of level of knowledge about each category, all 22 categories assessed showed statistically significant mean differences indicating perceived knowledge gain with the most knowledge gained for "resident satisfaction in the program." Of the nine program characteristics, clinical experience was the most important factor to participants. Participants (100%) were satisfied with the VE experience and indicated the VE gave them the opportunity to get to know the program. CONCLUSIONS: A virtual externship is a satisfactory option for increasing applicant knowledge of the tangible and intangible aspects of a residency program.

Application of a fluorescence EEM-PARAFAC model for direct and indirect potable water reuse monitoring: Multi-stage ozone-biofiltration without reverse osmosis at Gwinnett County, Georgia, USA.

Periods of drought coupled with increasing population growth have prompted increased interest in potable water reuse in Gwinnett County, Georgia, USA. However, such inland water recycling facilities are challenged with treatment approaches where reverse osmosis (RO) membrane concentrate disposal is a barrier to implementation of potable reuse. To evaluate alternative treatment processes, testing of two side-by-side pilot systems using multi-stage ozone and biological filtration without RO was conducted to compare indirect potable reuse (IPR) to direct potable reuse (DPR). Two water sources were investigated-influent from Lake Lanier for the IPR pilot, and a blend of 25 % reclaimed water mixed with lake water (75 %) for the DPR pilot. To assess the nature of organic matter removed during potable reuse, excitation-emission matrix (EEM) fluorescence spectroscopy/PARAllel FACtor (PARAFAC) analyses were examined as a fingerprinting tool. The objectives were to determine (a) if a DPR scenario, when preceded by advanced wastewater treatment, could achieve drinking water quality comparable to IPR and (b) if water quality monitoring using EEM/PARAFAC methods could predict results for DPR and IPR water quality, comparable to parameters obtained in a supplementary study that required more expensive, time-consuming, and complicated analytical techniques. Sample scores representing relative concentrations of fluorescing organic matter derived from the EEM-PARAFAC model decreased in the order of reclaimed water > lake water > DPR pilot > IPR pilot, demonstrating that EEM/PARAFAC could distinguish between DPR and IPR water quality. An assessment of a comprehensive list of individual organic compounds (reported separately) validated that blend ratios of 25 % reclaimed water, or higher mixed with lake water (75 %) did not meet primary and secondary drinking water standards. Likewise, in this study, EEM/PARAFAC analysis demonstrated the 25 % blend did not provide drinking water quality indicating this simple, inexpensive method could be used for potable reuse monitoring.

Dental students and recent dental graduates' perceptions of preparedness in treating pediatric patients.

PURPOSE/OBJECTIVES: To survey potential applicants applying to advanced education in pediatric dental programs and evaluate their preparedness upon graduating from an accredited dental school. METHODS: Attendees of a virtual externship of a University program were recruited to participate in a web-based survey. The survey collected demographic data, current levels of confidence with various pediatric clinical procedures, predicted confidence with those procedures, and number of procedures completed. Chi-Square and analysis of variance statistics were performed on resulting data to determine statistical significance. RESULTS: Fifty-three participants completed the survey in its entirety (n = 53). Most respondents reported adequate didactic training, mean score of 3.6 (range 0-5) and a moderate to high impact of coronavirus disease 2019 on their overall training with a mean score of 4.9 (range 0-10). Current dental students reported that they are "not confident at all" (<2.0) for 15/24 (63%) of the procedures. Graduates reported "somewhat confident" (<3.0) for 13/24 (54%) of the categories. Both students and graduates report the lowest levels of confidence for managing dental trauma, invasive treatment of young patients (<4 years of age), and patients with special healthcare needs. Dental students self-reported the expectation to feel more confident throughout their matriculation; however, their clinical experience was still reported to be limited. Students did not report reaching the level of "confident" for 75% of the procedures. CONCLUSION: Dental students and recent dental graduates alike perceive themselves to be under prepared for practice and do not feel confident in performing pediatric dental procedures. This study can provide dental schools, program directors, recent graduates, and dental students with an understanding of areas where they are under prepared and could offer areas where curricula and clinical experiences could be updated or modified.

Tooth Structure Removed in Primary Molar Prefabricated Crown Preparations of Typodont Teeth.

PURPOSE: Esthetic prefabricated pediatric crowns require more tooth reduction than stainless steel crowns due to their passive fit. The purpose of this study was to determine tooth reduction in primary molar preparations for various pediatric prefabricated crowns. METHODS: Fifty primary maxillary and fifty mandibular typodont molars were scanned with an optical scanner. The teeth were mounted in a typodont, and 10 experienced pediatric clinicians prepared them for five types of pediatric prefabricated crowns: (1) stainless steel (SS); (2) zirconia EZCrowns™ (EZ); (3) NuSmile ® ZR (NS); (4) Zirconia Kinder Krowns ® (KD); and (5) an experimental composite crown (PS). The prepared teeth were rescanned, and the pre- and postpreparation scans were precisely aligned. Mean and maximum reduction depths were calculated for occlusal and mesio- buccal surfaces. Differences in reduction among crown types were compared using one-way analysis of variance followed by the Student-Newman- Keuls post hoc test (α equals 0.05). RESULTS: Reduction depths were not significantly different among the esthetic crowns but were significantly higher than SS crowns. Maximum reduction exceeded two mm in some of the KD and NS crown preparations, with KD consistently showing the highest reduction. CONCLUSIONS: Preparations for esthetic prefabricated molar crowns were more extensive than SS crowns, especially at occlusal and mesiobuccal surfaces. Clinicians should carefully follow manufacturer preparation guidelines to avoid encroaching the mesiobucccal pulp horn.

Development of a fluorescence EEM-PARAFAC model for potable water reuse monitoring: Implications for inter-component protein-fulvic-humic interactions.

Measuring the surrogate parameters total organic carbon and dissolved organic carbon (TOC/DOC) is not adequate, alone, to reveal nuances in organic character for optimizing treatment in potable water reuse. Alternatively, analyzing each organic compound contributing to the surrogate measurement is not possible. As an additional analytical tool applied between these extremes, the use of excitation-emission matrix fluorescence spectroscopy with PARAllel FACtor (EEM-PARAFAC) analysis was investigated in this research to track categories (components) or families of organic compounds during treatment in recycled water schemes. Although not all organic molecules fluoresce, many do, and fluorescence helps track their fate through water treatment processes. The sites investigated in this research were Lake Lanier, in Gwinnett County, Georgia, USA; the F. Wayne Hill Water Resources Center (FWH WRC) advanced wastewater treatment facility; and two pilot facilities operated in parallel representing the current indirect potable reuse (IPR) scheme as well as a pilot that evaluated direct potable reuse (DPR). A four-component nonnegativity PARAFAC model-elucidating protein-like (including tyrosine- and tryptophan-like fluorescence in a single component), soluble microbial product (SMP)-like, fulvic-like, and humic-like components-was fitted to the data. Each of the four components was spectrally and mathematically separated, implying that the fluorescing SMP-like component was not comprised of protein-, fulvic-, or humic-like components. PARAFAC excitation loadings with dual (double) pairs of fluorescing regions centered at the same emission wavelengths but different excitation wavelengths oriented parallel to the excitation axis and perpendicular to the emission axis were attributed to individual PARAFAC components. Significantly, the observation of PARAFAC emission loadings with multiple peaks-where the protein-like component exhibited fluorescence in both protein and fulvic/humic regions-is proposed to signify an intermolecular energy transfer (< 10 nm). Correct identification of EEM-PARAFAC components is fundamental to understanding water treatment.

A Randomized Controlled Pilot Study Examining Effects of Animal Assisted Therapy in Children Undergoing Sealant Placement.

Purpose: The purpose of this study was to examine the effects of a companion canine on physiologic responses, discomfort level, and behavior in children undergoing sealant placement using a dental isolation system (Isodry®). Methods: Forty-seven healthy six- to 10-year-olds who needed sealants were randomly assigned to a control group (N =23) or experimental group (N =24) that utilized an emotional support canine in the child's lap. Preoperative baseline anxiety was obtained. Pulse, pulse oximetry, and behavior (measured by Frankl and Houpt scales) were recorded at various time points (beginning, at first sealant placement, switching the isolation system to the other side, second side sealant placement, and end) throughout the procedure. Participants reported a comfort level utilizing the FACES scale. Participants in the intervention group were asked, "Did you like having the dog in your lap?" The dentist rated the difficulty of and time required for the procedure. Results: Baseline anxiety was similar; no significant differences in physiologic measurements or FACES ratings were found between groups. The intervention group had significantly lower Houpt ratings for all three variables when the isolation system was repositioned (P=0.002, P=0.03, and P=0.05) and had higher Frankl scores at isolation repositioning and when completing sealants on the second side (P=0.02 and P=0.03, respectively). Both groups had similar ratings from the dentist. Conclusions: Animal-assisted therapy (AAT) should be studied more rigorously to substantiate its effectiveness in enhancing cooperative behavior in children for dental procedures. High levels of satisfaction were observed among pediatric users of AAT.

Color Stability of Prefabricated Pediatric Zirconia Crowns Following Sterilization.

Purpose: Since pediatric zirconia crowns (ZRCs) are prefabricated, they may be sterilized following try-in for re-use. Possible changes in color stability, gloss, and translucency were evaluated for four brands of prefabricated zirconia crowns following autoclave and cold sterilization. Methods: Sixteen maxillary right central incisor prefabricated ZRCs were obtained from NuSmile ®, Sprig, Cheng Crowns, and Kinder Krowns ® manufacturers and either autoclaved or cold sterilized. Gloss unit measurements were obtained with a small object Novo-Curve glossmeter. CIE-L*a*b* system values were measured with a CM-700d spectrophotometer under three different illuminants to calculate DE (quantitative representation of the perceived color). ΔE equals one was used for perceptibility threshold (PT) and ΔE equals 2.7 for acceptability threshold (AT). Results: All groups' baseline was ΔE less than one for all illuminants except Cheng Crowns to be autoclaved, indicating crowns are not identical in color from the manufacturer. For autoclaving, Cheng Crowns reached ΔE PT greater than one following the 10th sterilization cycle for all illuminants (D65 1.08±0.32 (standard deviation; P<0.001), A equals 1.07±0.32 (P<0.001), and F2 equals 1.25±0.38 (P<0.001). For cold sterilization, Sprig EZCrowns reached PT greater than one for all sterilization cycles, and Cheng Crowns reached ΔE PT greater than one for the sixth and 10th sterilization cycles. Gloss was not affected by either sterilization method. Spring EZcrowns had the highest mean translucency. Conclusions: Although each group may have a slight perceived difference, there was no clinically significant difference in color; all groups remained below the acceptability threshold of ΔE equals 2.7.