Effectiveness of population-based recovery actions for threatened southern mountain caribou.

Habitat loss is affecting many species, including the southern mountain caribou (Rangifer tarandus caribou) population in western North America. Over the last half century, this threatened caribou population's range and abundance have dramatically contracted. An integrated population model was used to analyze 51 years (1973-2023) of demographic data from 40 southern mountain caribou subpopulations to assess the effectiveness of population-based recovery actions at increasing population growth. Reducing potential limiting factors on threatened caribou populations offered a rare opportunity to identify the causes of decline and assess methods of recovery. Southern mountain caribou abundance declined by 51% between 1991 and 2023, and 37% of subpopulations were functionally extirpated. Wolf reduction was the only recovery action that consistently increased population growth when applied in isolation, and combinations of wolf reductions with maternal penning or supplemental feeding provided rapid growth but were applied to only four subpopulations. As of 2023, recovery actions have increased the abundance of southern mountain caribou by 52%, compared to a simulation with no interventions. When predation pressure was reduced, rapid population growth was observed, even under contemporary climate change and high levels of habitat loss. Unless predation is reduced, caribou subpopulations will continue to be extirpated well before habitat conservation and restoration can become effective.

Color- and strength-graded zirconia: Strength, light transmission, and composition.

STATEMENT OF PROBLEM: Natural teeth are graded in terms of translucency and strength. Graded zirconia materials are now available with a higher yttria content on the top or in the enamel zone to increase surface translucency and a lower yttria content on the bottom or in the dentin zone to increase strength. Such materials could provide multiple advantages over uniform materials and reduce the need for porcelain veneering in anterior artificial crowns; however, studies on the properties of these materials are lacking. PURPOSE: The purpose of this in vitro study was to measure and compare the biaxial flexural strength, percentage light transmission, elemental content, and phase content of zones within and among color graded zirconia blocks and color- and strength-graded zirconia blocks. MATERIAL AND METHODS: Disks of a color graded material (Katana STML) and a strength- and color-graded material (IPS e.max ZirCAD Prime) were fabricated (Zircom Furnace). Biaxial flexural strength was measured using a piston-on-3-ball test in a universal testing machine (n=10). Absolute light transmission was measured with a spectrophotometer. Elemental compositions were quantified for 3 zones in each of the 2 zirconia materials using X-ray fluorescence analysis. Zirconia phase fractions were quantified for 3 zones using X-ray diffraction analysis (XRD). Where appropriate, 2-way ANOVA, 1-way ANOVA, and Tukey multiple pairwise comparison testing were used to determine which of the 6 zones differed from one another (α=.05). RESULTS: The color-graded zirconia exhibited gradients in light transmission and differences in phase content in the 3 zones measured. The color- and strength-graded zirconia exhibited gradients in light transmission, biaxial flexural strength, elemental composition, and phase content in the 3 zones measured. The bottom, dentin, or intaglio layer of a strength graded zirconia material was substantially stronger than all other zones of either material (P<.05). The top, enamel, zones of both materials possessed high light transmissibility (P<.05). The 2 materials differed with respect to biaxial strength (P<.001), light transmission (P<.02), elemental composition, and phase composition overall, as well as in most zone-by zone comparisons (P<.05). The performance and composition of the color graded material was consistent with it being a 5Y material throughout. The performance and composition of the color and strength graded material was consistent with it having a 3Y bottom zone and a 5Y top zone. CONCLUSIONS: A strength-graded and color-graded zirconia material offers potential advantages in both strength and translucency.

Effects of aromatase inhibitor therapy on visceral adipose tissue area and cardiometabolic health in postmenopausal women with early and locally advanced breast cancer.

OBJECTIVE: Aromatase inhibitor (AI) therapy provides oncological benefits in postmenopausal women with oestrogen receptor-positive breast cancer. However, AI treatment has been associated with increased cardiovascular risk. In nonbreast cancer populations, experimentally induced low oestrogen states and natural transition to menopause have been associated with increases in visceral adipose tissue (VAT), a known surrogate marker for cardiometabolic risk. Given that AI treatment blocks oestradiol production, we hypothesized that AI treatment would increase VAT. METHODS: We conducted a prospective 12-month cohort study of 52 postmenopausal women newly initiating AI treatment (median age: 64.5 years) and 52 women with breast pathology not requiring endocrine therapy (median age: 63.5 years). VAT area and other body composition parameters were measured at baseline, 6 months and 12 months using dual X-ray absorptiometry. Other risk markers of cardiometabolic health were also assessed. RESULTS: In women initiating AI treatment, there was no statistically significant difference in VAT area after 12 months when compared to controls, with a mean adjusted difference of -5.00 cm2 (-16.9, 6.91), p = .55. Moreover, changes in total fat mass, lean mass, subcutaneous adipose tissue area, hepatic steatosis and measures in endothelial function were also not statistically different between groups after 12 months. Findings were similar after adjustments for activity levels and coronavirus disease 2019 lockdown duration. CONCLUSIONS: These data provide reassurance that over the initial 12 months of AI therapy, AI treatment is not associated with metabolically adverse changes in body composition, hepatic steatosis or vascular reactivity. The impact of extended AI therapy on cardiometabolic health requires further study.

Influence of yttria content and surface treatment on the strength of translucent zirconia materials.

STATEMENT OF PROBLEM: Newly developed translucent zirconia materials have been used for anterior monolithic complete coverage restorations. Surface treatments can improve adhesion, as well as decrease or increase the strength of ceramics. However, information on the influence of surface treatments on the strength of translucent zirconias is sparse. PURPOSE: The purpose of this in vitro study was to measure and characterize the effects of different surface treatments, including airborne-particle abrasion, on the strength of different translucent 4 mol% and 5 mol% yttria-stabilized zirconia materials. MATERIALS AND METHODS: Disks (N=160) made from 4 types of translucent yttria-stabilized zirconia materials were surface-treated in 4 ways: Control groups were hand-polished with 2000-grit silicon carbide abrasive paper; as-machined; glass bead airborne-particle abraded; and alumina airborne-particle abraded. The biaxial flexural strength was measured by using a piston-on-3-ball test in a universal testing machine. The simple main effects of material type and surface treatment and their interaction on biaxial flexural strength were evaluated with 2-way ANOVA (α=.05). A priori, 1-way ANOVA and the Tukey multiple comparisons tests were used within material and treatment types (α=.05). Surface morphology was assessed by using scanning electron microscopy. Translucency, absolute transmittance, was measured by using a spectrophotometer. RESULTS: Two-way ANOVA revealed that the effects of zirconia type, surface treatment, and their interaction all significantly affected biaxial flexural strength (P<.001). One-way ANOVA revealed that the 4Y material was stronger than all 5Y materials, regardless of surface treatment; all 5Y materials were ranked from strongest to weakest as polished; as-machined, or glass bead abraded; and alumina abraded. The 4Y material was stronger when alumina abraded than when glass bead abraded. Scanning electron microscopy showed that as-polished surfaces were smoother than all others; as-machined and glass bead abraded surfaces displayed little difference; alumina abraded was the roughest; and differences among materials were not discerned. The 1-way ANOVA and multiple comparisons testing showed that the 4Y material had less absolute transmittance, approximately 5% less, than all the 5Y materials. CONCLUSIONS: Zirconia material type and surface treatment influenced the strength of translucent zirconia materials; a 4 mol% zirconia material was stronger than 5 mol% zirconia materials for all surface treatments tested; airborne-particle abrasion using alumina had a slight strengthening effect on a 4 mol% zirconia but had a weakening effect on 5 mol% materials; airborne-particle abrasion by using alumina produced the roughest surfaces on all materials; and the 4 mol% material was slightly less translucent than the 5 mol% materials.

Symptomology following mRNA vaccination against SARS-CoV-2.

Despite demonstrated efficacy of vaccines against severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causative agent of coronavirus disease-2019 (COVID-19), widespread hesitancy to vaccination persists. Improved knowledge regarding frequency, severity, and duration of vaccine-associated symptoms may help reduce hesitancy. In this prospective observational study, we studied 1032 healthcare workers who received both doses of the Pfizer-BioNTech SARS-CoV-2 mRNA vaccine and completed post-vaccine symptom surveys both after dose 1 and after dose 2. We defined appreciable post-vaccine symptoms as those of at least moderate severity and lasting at least 2 days. We found that symptoms were more frequent following the second vaccine dose than the first (74% vs. 60%, P < 0.001), with >80% of all symptoms resolving within 2 days. The most common symptom was injection site pain, followed by fatigue and malaise. Overall, 20% of participants experienced appreciable symptoms after dose 1 and 30% after dose 2. In multivariable analyses, female sex was associated with greater odds of appreciable symptoms after both dose 1 (OR, 95% CI 1.73, 1.19-2.51) and dose 2 (1.76, 1.28-2.42). Prior COVID-19 was also associated with appreciable symptoms following dose 1, while younger age and history of hypertension were associated with appreciable symptoms after dose 2. We conclude that most post-vaccine symptoms are reportedly mild and last <2 days. Appreciable post-vaccine symptoms are associated with female sex, prior COVID-19, younger age, and hypertension. This information can aid clinicians in advising patients on the safety and expected symptomatology associated with vaccination.

Assessing pesticide, trace metal, and arsenic contamination in soils and dam sediments in a rapidly expanding horticultural area in Australia.

Industrial horticulture can release pesticides and trace metals/metalloids to terrestrial and aquatic environments. To assess long-term and more recent land contamination from an expanding horticultural region, we sampled soils from chemical mixing, crop production, and drainage areas, as well as retention reservoirs (dam) sediments, from 3 blueberry farms with varying land-use history in subtropical Australia. Soils were analysed for 97 different pesticides and trace metal/metalloid contents. The most recent farm had fungicides propiconazole and cyprodinil contents that may compromise soil invertebrate survival and/or nutrient recycling (5-125 mg kg-1). A site previously used to cultivate bananas had 6 dam sediment subsamples with arsenic contents over sediment quality guidelines (SQG); however, the soil content values were just below Australian health investigation levels (100 mg kg-1). Arsenic is suspected to originate from pesticide application during previous banana cultivation in the region. Dam sediment cores at all sites had mercury contents over the SQG likely due to fungicides or fertiliser impurities. Mean contents of mercury from dam sediments (141 ± 15.5 µg kg-1) were greater than terrestrial soils (78 ± 6.5 µg kg-1), and sediment profiles suggest mercury retention in anoxic sediments. Soils in chemical mixing areas at two sites were contaminated with copper and zinc which were above the national soil ecological investigation levels. Based on toxicity data, distribution, persistence, and mobility, we identified the fungicide cyprodinil, mercury, and phosphorus as contaminants of the greatest concern in this intensive horticulture area of Australia. Additional sampling (spatial, chemical speciation, biotic) is required to support mitigation efforts of the emerging contamination in the rapidly expanding blueberry farms of this region of Australia.

The Role of Exparel Plus Meloxicam for Postoperative Pain Management.

PURPOSE OF REVIEW: Acute postoperative pain reduction is a major target against the opioid crisis. While opioids have traditionally been the mainstay for postoperative analgesia, current practice has focused on a multimodal approach to pain control, including ultrasound-guided blocks with longer acting local anesthetic agents. RECENT FINDINGS: Non-steroidal anti-inflammatory drugs (NSAIDs), such as meloxicam, are an important class of medications utilized to manage pain in the perioperative period. An additional treatment used in perioperative or postoperative pain relief is Exparel, a bupivacaine (sodium channel blocker) liposomal injectable suspension with a 3-4-day duration of action. The long-acting mechanism and formulation of Exparel consistently has demonstrated decreased opioid use and pain scores in patients undergoing many different surgical procedures. A concern is that pH negatively alters the efficacy of bupivacaine, as in cases of inflamed tissue and acidic fluid pH. For this reason, a combination medication with both meloxicam and bupivacaine has been developed, which normalizes pH and has anti-inflammatory and anti-pain conduction properties. Clinical studies demonstrate that this combination agent can be extremely beneficial in treating postoperative pain. This manuscript summarizes the newest developments with regard to liposomal bupivacaine and the non-steroidal meloxicam, their roles in effective treatment of postoperative pain, contraindications, special considerations of using these medications, and future considerations. HTX-011 pairs up a new extended-release formulation of the local anesthetic bupivacaine with meloxicam, a well-established non-steroidal anti-inflammatory drug (NSAID).

The benefits of adding metformin to tamoxifen to protect the endometrium-A randomized placebo-controlled trial.

BACKGROUND: We investigated whether metformin prevents tamoxifen-induced endometrial changes and insulin resistance (IR) after a diagnosis of breast cancer. METHODS: This was a single-centre, randomized, double-blind, placebo-controlled, parallel group trial. Postmenopausal women with hormone receptor-positive breast cancer taking tamoxifen were randomly allocated to metformin 850 mg or identical placebo, twice daily, for 52 weeks. Outcome measures included double endometrial thickness (ET) measured by transvaginal ultrasound, fasting insulin, glucose and IR estimated by the homeostasis model of assessment (HOMA-IR). RESULTS: A total of 112 women were screened and 102 randomized. Results are presented as median (range). The 101 women who took at least one dose of medication were aged 56 (43-72) years, with 5(0.5-28) years postmenopause, and had taken tamoxifen for 28.9 (0-367.4) weeks. The baseline ET was 2.9 mm (1.4-21.9) for the placebo group (n = 52) and 2.5 mm (1.3-14.8) for the metformin group (n = 50). At 52 weeks, the median ET was statistically significantly lower for the metformin (n = 36) than for the placebo group (n = 45) (2.3 mm (1.4-7.8) vs 3.0 (1.2-11.3); P = 0.05). 13.3% allocated to placebo had an ET greater than 4 mm vs 5.7% for metformin (P = 0.26). There was no endometrial atypia or cancer. Compared with placebo, metformin resulted in significantly greater baseline-adjusted reductions in weight (P < 0.001), waist circumference (0.03) and HOMA-IR (P < 0.001). CONCLUSIONS: Metformin appears to inhibit tamoxifen-induced endometrial changes and has favourable metabolic effects. Further research into the adjuvant use of metformin after breast cancer and to prevent EH and cancer is warranted.

Culturally and linguistically diverse oncology patients' perspectives of consultation audio-recordings and question prompt lists.

OBJECTIVE: Ethnicity and migrant status result in disparities with cancer burden and survival, with communication difficulties cited as the main barrier to access. Our research team tested a communication intervention package comprising consultation audio-recordings (ARs) and question prompt lists (QPLs) for low English-speaking (LES) patients with cancer. This study explored LES patient experiences, preferences, and recommendations regarding the communication package. METHODS: Participants completed a questionnaire and qualitative interview regarding ARs and QPLs. Eligibility criteria comprised aged ≥18 years old; a consultation with an oncologist between June 1, 2015 and April 1, 2016; an Arabic, Cantonese, Greek, or Mandarin professional interpreter booked for that consultation; and randomised to receive the communication intervention. RESULTS: Eighteen patients completed the qualitative interview and 17 completed the questionnaire. Fifteen reported listening to the AR at least once. Participants reported that QPLs and ARs provide support and assistance with remembering and understanding medical information. Both resources were seen as having applicability beyond the oncology setting in regards to improving health service delivery and continuity of care. However, patients felt that individual tailoring of the resources should be considered. Patients also found it useful to share ARs with family. CONCLUSIONS: The LES participants in this study considered the ARs and QPLs useful for most, but not all contexts. Recommendations regarding delivery and use highlight that these resources should be tailored and patient-driven. Further, patients foresaw a range of additional uses for consultation ARs within the broader healthcare context.

Exploring disparities in receipt of adjuvant chemotherapy in culturally and linguistically diverse groups: an Australian centre's experience.

BACKGROUND: Globally, racial and ethnic disparities exist in treatments and outcomes for cancer patients. In Australia, there are few published data related to cancer patients from culturally and linguistically diverse (CALD) backgrounds. AIM: To explore disparities in adjuvant chemotherapy utilisation in cancer patients from CALD groups. METHODS: Retrospective analysis of patients who were recommended adjuvant chemotherapy for early stage breast cancer or early stage colorectal cancer between July 2011 and October 2014 was performed. Rates of adjuvant chemotherapy uptake were analysed between those who identified English as their first-preferred language, versus those who did not, as well as between patients who were born in a country where English is the main language (non-CALD), versus those born in a country where English is not the main language (CALD). RESULTS: Two hundred and eleven patients were identified. One hundred and forty-three (67.7%) patients had early stage breast cancer and 68 (32.2%) patients had early stage colorectal cancer. No difference was detected in the acceptance of adjuvant chemotherapy between non-CALD (80.9%) and CALD patients (81.3%, P = 0.984) or between patients who identified English as their first-preferred language (80.8%) and those who did not (81.8%, P = 0.870). There was no difference in the rate of chemotherapy completion, with 75.6% completion in the non-English-speaking group and 81.1% in the English-speaking group (P = 0.426). CONCLUSION: No difference was observed in adjuvant chemotherapy utilisation in patients who identified English as their first-preferred language compared to those who did not, as well as between non-CALD and CALD groups. This is the first study to assess these differences in Australia.

Effect of tooth substrate and porcelain thickness on porcelain veneer failure loads in vitro.

STATEMENT OF PROBLEM: Bonded porcelain veneers are widely used esthetic restorations. High success and survival rates have been reported, but failures do occur. Fractures are the commonest failure mode. Minimally invasive or thin veneers have gained popularity. Increased enamel and porcelain thickness improve the strength of veneers bonded to enamel, but less is known about dentin or mixed substrates. PURPOSE: The purpose of this in vitro study was to measure the influences of tooth substrate type (all-enamel, all-dentin, or half-dentin-half-enamel) and veneer thickness on the loads needed to cause initial and catastrophic porcelain veneer failure. MATERIAL AND METHODS: Model discoid porcelain veneer specimens of varying thicknesses were bonded to the flattened facial surfaces of incisors with different enamel and dentin tooth substrates, artificially aged, and loaded to failure with a small sphere. Initial and catastrophic fracture events were identified and analyzed statistically and fractographically. RESULTS: Fracture events included initial Hertzian cracks, intermediate radial cracks, and catastrophic gross failure. All specimens retained some porcelain after catastrophic failure. Cement failure occurred at the cement-porcelain interface not at the cement-tooth interface. Porcelain veneers bonded to enamel were substantially stronger and more damage-tolerant than those bonded to dentin or mixed substrates. Increased porcelain thickness substantially raised the loads to catastrophic failure on enamel substrates but only moderately raised the loads to catastrophic failure on dentin or mixed substrates. The veneers bonded to half-dentin-half-enamel behaved remarkably like those bonded wholly to dentin. CONCLUSIONS: Porcelain veneers bonded to enamel were substantially stronger and more damage-tolerant than those bonded to dentin or half-enamel-half dentin.

Influence of increased patient age on longitudinal outcomes of root canal treatment: a systematic review.

OBJECTIVES: To conduct a systematic review of longitudinal endodontic outcomes in elders. BACKGROUND: Negative opinions about the prognosis of non-surgical root canal treatment (NSRCT) in elders affect decisions made by patients and dentists. Patient, caregiver and dentist attitudes and behaviours may interact to decrease the provision of NSRCT. Critical examination of the available evidence through systematic review could provide objective data to assist patients, caregivers, healthcare providers and third-party payers in making decisions about the efficacy of NSRCT in elders and provide a robust foundation for the health promotion of NSRCT in elders. METHODS: Inclusion/exclusion criteria were used for defined searches in MEDLINE and Cochrane CENTRAL. Title lists were scanned, and abstracts read to determine utility; articles meeting inclusion/exclusion criteria were analysed. Data were extracted and compiled into a table of evidence. RESULTS: Defined searching produced 3605 titles; 24 articles were included, nine prospective and 15 retrospective. Overall study quality was good. Patient samples mostly represented modern populations from countries with very high human development indices. Over 17 430 teeth were included. Meta-analysis was not attempted due to heterogeneity in reporting. All 24 included papers demonstrated that increased patient age did not decrease the success or survival rates of NSRCT. CONCLUSIONS: This systematic review of longitudinal NSRCT outcomes demonstrated that increased patient age did not decrease the success of NSRCT. Patient age is not a prognostic factor for NSRCT. Age should not be considered by dentists or patients when making NSRCT decisions.

Protein Interaction between Ameloblastin and Proteasome Subunit α Type 3 Can Facilitate Redistribution of Ameloblastin Domains within Forming Enamel.

Enamel is a bioceramic tissue composed of thousands of hydroxyapatite crystallites aligned in parallel within boundaries fabricated by a single ameloblast cell. Enamel is the hardest tissue in the vertebrate body; however, it starts development as a self-organizing assembly of matrix proteins that control crystallite habit. Here, we examine ameloblastin, a protein that is initially distributed uniformly across the cell boundary but redistributes to the lateral margins of the extracellular matrix following secretion thus producing cell-defined boundaries within the matrix and the mineral phase. The yeast two-hybrid assay identified that proteasome subunit α type 3 (Psma3) interacts with ameloblastin. Confocal microscopy confirmed Psma3 co-distribution with ameloblastin at the ameloblast secretory end piece. Co-immunoprecipitation assay of mouse ameloblast cell lysates with either ameloblastin or Psma3 antibody identified each reciprocal protein partner. Protein engineering demonstrated that only the ameloblastin C terminus interacts with Psma3. We show that 20S proteasome digestion of ameloblastin in vitro generates an N-terminal cleavage fragment consistent with the in vivo pattern of ameloblastin distribution. These findings suggest a novel pathway participating in control of protein distribution within the extracellular space that serves to regulate the protein-mineral interactions essential to biomineralization.

A non-randomized dose-escalation Phase I trial of a protein-based immunotherapeutic for the treatment of breast cancer patients with HER2-overexpressing tumors.

This Phase I dose-escalation study (NCT00058526) assessed the safety and immunogenicity of an anti-cancer immunotherapeutic (recombinant HER2 protein (dHER2) combined with the immunostimulant AS15) in patients with early-stage HER2-overexpressing breast cancer (BC). Sixty-one trastuzumab-naive patients with stage II-III HER2-positive BC received the dHER2 immunotherapeutic after surgical resection and adjuvant therapy. They were allocated into four cohorts receiving different doses of dHER2 (20, 100, 500 µg) combined with a fixed AS15 dose. Safety and immunogenicity (dHER2-specific antibody responses) were assessed. After completing the immunization schedule (three or six doses over 14 weeks) and a six-month follow-up, the patients were followed for 5 years for late toxicity, long-term immunogenicity, and clinical status. The immunizations were well tolerated, and increasing doses of dHER2 had no impact on the frequency or severity of adverse events. Few late toxicities were reported, and after 5 years 45/54 patients (83.3 %) were still alive, while 28/45 (62 %) with known disease status were disease free. Regarding the immunogenicity of the compound, a positive association was found between the dHER2 dose, the immunization schedule, and the prevalence of dHER2-specific humoral responses. Among the patients receiving the most intense immunization schedule with the highest dHER2 dose, 6/8 maintained their dHER2-specific antibody response 5 years after immunization. The dHER2 immunotherapeutic had an acceptable safety profile in early HER2-positive BC patients. dHER2-specific antibody responses were induced, with the rate of responders increasing with the dHER2 dose and the number and frequency of immunizations.

Prevalence of root canal treatment and periapical radiolucency in elders: a systematic review.

INTRODUCTION: Neither the prevalence of periapical radiolucency (PARL), a surrogate for disease, nor the prevalence of non-surgical root canal treatment (NSRCT) in elders have been subjected to systematic review. The purpose of this study was to conduct systematic review and meta-analysis of the prevalence of PARL and NSRCT in elders. METHODS: Inclusion/exclusion criteria were used for defined searches in MEDLINE and Cochrane CENTRAL. Title lists were scanned and abstracts read to determine utility; articles meeting the criteria were analyzed. Weighted mean percentages were calculated for prevalence of PARL, NSRCT, and PARL in both teeth with and without NSRCT. RESULTS: Defined searching produced 3576 titles; 29 prevalence articles were included. Patient samples mostly represented modern populations from countries with very high human development indices. Meta-analyses were performed on up to 74 000 elders' teeth. For those aged 65+, the prevalence of all teeth with NSRCT was extremely high, 21%; the prevalence of all teeth with PARL was quite high, 7%; the prevalence of PARL in NSRCT teeth was high, 25%; and the prevalence of PARL in untreated teeth was surprisingly high, 4%. In elders, the prevalence of NSRCT and PARL separately increased with age; whereas, PARL in NSRCT teeth decreased with age. CONCLUSIONS: In comparison to general adult populations, elders had: a much higher prevalence of NSRCT, a higher prevalence of PARL, a lower prevalence of PARL in NSRCT teeth, and a higher prevalence of PARL in untreated teeth. Teeth saved through NSRCT were preferentially retained by elders.

Prevalence of Enamel Markings on Third Molars.

The purpose of this study was to measure the prevalence of enamel markings in routinely extracted third molars. One hundred donated third molars were examined. All had some marking(s). Caries was almost universal; white snowcapping of cusps and ridges was extremely common; pit and valley defects were very common; spots and bands were very common, most were white; horizontal grooves were common; linear enamel hypoplasia, considered to be a true developmental defect, was rare.

Compound complex curves: the authentic geometry of esthetic dentistry.

Observers are drawn to the intricate and unpredictable way light reflects off the compound complex curved surfaces seen in nature, art, and industry. Teeth are no exception, containing as they do such detail in their gross anatomy, fine anatomic detail, and surface texture. Compound complex curves are particularly important when engineered materials are used to mimic naturally occurring objects, including prosthetic teeth, and they can provide both authenticity and beauty. The purpose of this article was to describe the nature of compound complex curves, their historical context, and their importance in creating natural-looking prostheses. Classically, such curves have been described by using descriptive qualitative methods or quantitative mathematical methods; now these approaches merge. Natural tooth anatomy contains interlinked features at different levels of scale from gross to fine surface texture detail. These curves should be created appropriately for individual restorative treatments.

Effect of porcelain and enamel thickness on porcelain veneer failure loads in vitro.

STATEMENT OF PROBLEM: Bonded porcelain veneers are widely used esthetic restorations. Although high success and survival rates have been reported, failures occur. Fracture is the most common failure mode. Fractures range from incomplete cracks to the catastrophic. Minimally invasive or thin partial veneers have gained popularity. PURPOSE: The aim of this study was to measure the influences of porcelain veneer thickness and enamel substrate thickness on the loads needed to cause the initial fracture and catastrophic failure of porcelain veneers. MATERIAL AND METHODS: Model discoid porcelain veneer specimens of varying thickness were bonded to the flattened facial surfaces of incisors, artificially aged, and loaded to failure with a small sphere. Individual fracture events were identified and analyzed statistically and fractographically. RESULTS: Fracture events included initial Hertzian cracks, intermediate radial cracks, and catastrophic gross failure. Increased porcelain, enamel, and their combined thickness had like effects in substantially raising resistance to catastrophic failure but also slightly decreased resistance to initial Hertzian cracking. Fractographic and numerical data demonstrated that porcelain and tooth enamel behaved in a remarkably similar manner. As porcelain thickness, enamel thickness, and their combined thickness increased, the loads needed to produce initial fracture and catastrophic failure rose substantially. Porcelain veneers withstood considerable damage before catastrophic failure. CONCLUSIONS: Increased enamel thickness, increased porcelain thickness, and increased combined enamel and porcelain thickness all profoundly raised the failure loads necessary to cause catastrophic failure. Enamel and feldspathic porcelain behaved in a like manner. Surface contact damage occurred initially. Final catastrophic failure followed flexural radial cracking. Bonded porcelain veneers were highly damage tolerant.

Dentists' knowledge of non-surgical root canal treatment, a systematic review.

OBJECTIVES: Dental practice is based upon dentists' cognitions, knowledge being foundational. Knowledge is attained through education and perception. Although knowledge is modulated by beliefs, attitudes, preferences, and behaviors, it is essential to evidence-based practice. Cross-sectional studies uniformly demonstrate that community NSRCT is of sub-optimal quality worldwide, is lack of knowledge a problem? Our purpose was to measure dentists' knowledge of root canal treatment (NSRCT). DATA: Quantitative and qualitative data were extracted: purpose, topics assessed, authors cited knowledge sources, number of dentists studied, number of questions, authors descriptors of knowledge level,% correct answers by question, authors recommendations. SOURCES: OVID Medline, EMBASE, Web of Science, and hand-searching. STUDY SELECTION: Studies which had measured dentists' knowledge of non-surgical root canal treatment that was valuable, reliable, and had practical implications which could be implemented. A total of 51 papers from 19 countries measured the knowledge of 15,580 dentists using 445 questions on 29 root canal treatment topics. CONCLUSIONS: 'Gold standards' were from literature, external bodies, or expert consensus in 47, 31, and 2 papers respectively. Levels of knowledge by percentage correct answers among studies were poor to moderate and varied considerably. The mean, for the 50 studies where overall study percentages could be calculated, was 57 %, standard deviation 17 %, and a range of 16 % to 82 %. Authors' adjectives describing knowledge levels were generally negative. Additional education was advised in 49 papers, but without evidence that education was inadequate; 6 papers recommended increased use of protocols; only 5 papers advocated research on the cause of lack of knowledge. CLINICAL SIGNIFICANCE: Dentists' root canal treatment knowledge was found to be poor to moderate, as well variable. This may constrain quality of care. However, provision of information without attention to dentists' cognitions and motivations may not be successful. Educational strategies and goals should be re-evaluated. Evidence-based practice faces many barriers.

Soil microbial communities and degradation of pesticides in greenhouse effluent through a woodchip bioreactor.

Pesticides, including insecticides and fungicides, are major contaminants in the effluent from intensive agricultural systems, such as greenhouses. Because of their constant use and persistence, some pesticides can accumulate in soil and/or run off into adjacent waterways. Microbial communities in soil can degrade some pesticides, and bioreactors with enhanced microbial communities have the potential to facilitate decontamination before the effluent is released into the environment. In this study, we sampled the soil along a gradient from immediately below greenhouses, into, through and below a bioreactor. Multi-analyte pesticide screening was undertaken along with shotgun metagenomic sequencing, to assess microbial community taxonomic profiles and metabolic pathway responses for functional analysis. Two insecticides (imidacloprid and fipronil) and nine fungicides were identified in the soil samples, with a general decrease in most pesticides with increasing distance from the greenhouses. Diversity indexes of taxonomic profiles show changes in the microbial community along the gradient. In particular, microbial communities were significantly different in the bioreactor, with lower Shannon diversity compared to immediately below the greenhouses, in the channels leading into the bioreactor and further downstream. Metabolic pathway analysis revealed significant changes in a wide range of core housekeeping genes such as protein/amino acid synthesis and lipid/fatty acid biosynthesis among the sampling sites. The result demonstrates that the composition and potential functional pathways of the microbial community shifted towards an increased tendency for phytol and contaminant degradation in the bioreactor, facilitated by high organic matter content. This highlights the potential to use enhanced microbial communities within bioreactors to reduce contamination by some pesticides in sediment receiving run-off from greenhouses.