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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., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Certain countries including the United States remain non-endemic for particular infectious diseases such as equine piroplasmosis through import restrictions and surveillance. Endemic regions often employ premunition as the primary method to control disease, however in non-endemic countries, chemosterilization combined with methods to confirm parasite elimination are required to maintain disease-free status. The ability of imidocarb diproprionate (ID) to clear persistent Theileria equi infection from infected horses has been shown through the inability of treated horses to transmit via blood transfer. However, the common lengthy persistence of anti-T. equi antibody causes regulatory tests such as cELISA or IFA to remain positive for extended periods. Persistence of positive testing creates challenges for regulatory veterinary medicine and international trade. Concordance between nested polymerase chain reaction (nPCR) targeting the ema1 gene and immunoblotting (IB) measuring declination in anti-EMA1 and anti-EMA2 antibody were used to verify clearance of T. equi from 179 ID-treated horses. These data support the use of IB to demonstrate declining anti-EMA1 and EMA2 titers in T. equi-infected horses subsequent to successful ID treatment. Such data provide concordant support to a negative nPCR and allow for a more timely determination of effective ID clearance of T. equi. The post ID treatment results indicate that while nPCR was consistently negative by 14 days and cELISA generally remained positive after 1 year, immunoblot was on average negative after 4 months and 100% in agreement with nPCR., (Copyright © 2017 Elsevier GmbH. All rights reserved.)

Introduction: Anxiety is an emotion characterized by feelings of tension, worried thoughts, and physical changes. Dental anxiety has been associated with pain, fear, care avoidance, and more invasive treatments including nonsurgical root canal treatment (NSRCT). The very words root canal are deeply embedded in societal consciousness. Better understanding of dental anxiety may prevent treatment avoidance. The purpose of this study was to conduct a systematic review of NSRCT-associated anxiety., Methods: Inclusion/exclusion criteria defined MEDLINE, Cochrane Library, psychINFO, manual, and citation searches. Title lists and abstracts were read to determine utility; data were extracted, summarized, and compiled into an evidence table, and meta-analyses were performed., Results: Defined searching produced 835 titles; 36 articles were included, mostly representing modern populations from countries with very high human development indices. Major sources of heterogeneity included differing study aims, outcome measures, clinical settings, locations, operators, sample selection, and sample size. Meta-analysis of 18 articles including 1989 subjects gave a pretreatment anxiety rating of 39 (standard deviation, 9) on a normalized 100-point scale. Meta-analysis of 4 articles including 232 subjects gave a post-treatment anxiety rating of 27 (standard deviation, 5) on a normalized 100-point scale, representing a 30% reduction. A L'Abbe plot of 5 studies also showed that anxiety decreased after NSRCT. Limited data indicated that gender, age, and prior NSRCT experience influenced NSRCT-associated anxiety. NSRCT-associated anxiety was ranked high among dental treatments, often close to oral surgery., Conclusions: NSRCT-associated anxiety was generally moderate. Anxiety decreased after NSRCT. Limited evidence suggested that anxiety is influenced by patient and treatment factors., (Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Background and Overview: Initial root canal treatment is highly successful, appreciated by patients, and cost-effective, but failures occur. Should a tooth with unsuccessful initial root canal treatment be treated by means of other endodontic procedures or be replaced by a single-tooth implant?, Results: Results from systematic reviews of the outcomes of nonsurgical retreatment, apical surgery, replantation, and autotransplantation show high tooth survival rates. Nonsurgical retreatment generally is prioritized before surgical endodontic treatment. Microsurgical endodontic treatment is superior to traditional surgical endodontic treatment and has high survival rates. Intentional replantation remains a viable alternative to extraction. Autotransplantation has a place, particularly in growing patients with an appropriate donor tooth. Single-tooth implants have higher survival rates, but the natural state has intrinsic value., Conclusions: The first-line treatment option after failure of initial root canal treatment is nonsurgical retreatment. Endodontic surgery, intentional replantation, and autotransplantation should be considered before extraction and replacement by a single-tooth implant., Practical Implications: Comprehensive case assessment, evaluation of all endodontic options, and risk assessment for caries and periodontal disease are always necessary when choosing the optimal treatment for a patient when initial root canal treatment has failed to heal., (Copyright © 2016 American Dental Association. Published by Elsevier Inc. All rights reserved.)

Introduction: Although nonsurgical initial root canal treatment and retreatment have high success rates, periapical disease can remain. The survival rates of 2 surgical procedures, intentionally replanted (IR) teeth and implant-supported single crowns (ISCs), have yet to be compared. The purpose of this systematic review and meta-analysis was to examine the literature and quantify the survival of IR teeth and compare it with that of ISCs., Methods: Systematic searches were enriched by citation mining. Weighted survival means and 95% confidence intervals (CI) were estimated using a random-effects model and compared., Results: The quality of the IR and ISC articles was only moderate. Data for ISCs were much more plentiful than for IR teeth. Meta-analysis revealed a weighted mean survival of 88% (95% CI, 81%-94%) for IR teeth. Root resorption was reported with a mean prevalence of 11%. The weighted mean survival of ISCs was 97% (95% CI, 96%-98%). The mean survival of ISCs was significantly higher than that of IR teeth (P < .001). A recent study on IR teeth indicated that orthodontic extrusion before intentional replantation improved survival rates., Conclusions: A systematic review and meta-analysis found that the mean survival of ISCs was significantly higher than IR teeth. However, treatment decisions must be based on a wide variety of treatment and patient-specific parameters. Intentional replantation may have a role when ISC is not practicable. Studies using contemporary treatment and analytic methods should be used to identify and measure intentional replant prognostic and treatment variables., (Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: Clinicians are regularly confronted with difficult choices. Should a tooth that has not healed through nonsurgical root canal treatment be treated through endodontic microsurgery or be replaced using a single implant? Acquiring complete, unbiased information to help clinicians and their patients make these choices requires a systematic review of the literature on treatment outcomes. The purpose of this systematic review was to compare the outcomes of tooth retention through endodontic microsurgery to tooth replacement using an implant supported single crown., Methods: Searches performed in PubMed, Cochrane Library, Web of Science, and EMBASE databases were enriched by citation mining. Inclusion criteria were defined. Sentinel articles were identified and included in the final selection of studies. Weighted survival and success rates for single implants and endodontic microsurgery were calculated., Results: The quality of the articles reporting on single implants and endodontic microsurgery was moderate. Data for single implants were much more plentiful than for endodontic microsurgery, but the endodontic microsurgery studies had a slightly higher quality rating. Single implants and endodontic microsurgery were not directly compared in the literature. Outcomes criteria were often unclear. At 4-6 years, single implants had higher survival rates than teeth treated with endodontic microsurgery. Qualitatively different success criteria precluded valid comparison of success rates., Conclusions: Survival rates for single implants and endodontic microsurgery were both high (higher for single implants). Appraisal was limited by a lack of direct treatment comparisons. Long-term studies with a broad range of carefully defined outcomes criteria are needed., (Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Carious lesions exhibit a complex structural organization composed of zones of higher and lower mineralization, formed by successive periods of cyclic de- and re-mineralization. A thorough understanding of the lesion morphology is necessary for the development of suitable treatments aiming to repair rather than replace the damaged tissue. This detailed understanding includes the entire lesion down to individual crystallites and nanopores within the natural organization of the crown. A moderate lesion, with surface loss and reaching dentin, and a very early lesion were studied. Scanning small-angle X-ray scattering (SAXS) with a pixel size of 20 × 20 μm(2) was used to characterize these lesions, allowing for the identification of distinct zones with varied absorption and scattering behavior, indicative of varied porosity and pore morphology. Despite these differences, the overall orientation and anisotropy of the SAXS signal was unaltered throughout both lesions, indicating that an anisotropic scaffold is still present in the lesion. The finding that crystallite orientation is preserved throughout the lesions facilitates the identification of preventive re-mineralizing strategies with the potential to recreate the original nanostructure., (Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.)

Introduction: Cross-sectional studies describe the health status of a population and measure the prevalence of disease or treatment. Neither the prevalence of periapical radiolucency, a surrogate for disease, nor the prevalence of root canal treatment have been subjected to a systematic review, which is the highest level of clinical evidence. The purpose of this study was to conduct a systematic review and meta-analysis of the prevalence of periapical radiolucency and nonsurgical root canal treatment., Methods: Inclusion/exclusion criteria were used for defined searches in MEDLINE and EMBASE. Title lists were scanned and abstracts were read to determine utility. Articles meeting the inclusion/exclusion criteria were analyzed for heterogeneity. Weighted mean percentages were calculated for the prevalence of overall periapical radiolucency, root canal treatment, and apical radiolucency in both treated and untreated teeth., Results: Defined searching produced 11,491 titles. Thirty-three articles were included. Most patient samples represented modern populations from countries with high or very high human development indices. Meta-analysis was performed on 300,861 teeth. Of these, 5% had periapical radiolucencies, and 10% were endodontically treated. Of the 28,881 endodontically treated teeth, 36% had periapical radiolucencies; however, cross-sectional studies cannot distinguish between healing and failing cases. Of the 271,980 untreated teeth, 2% had periapical radiolucencies. The technical quality of root canal treatment was decried by most authors of the included studies., Conclusions: The prevalence of periapical radiolucency was very high, broadly equivalent to 1 radiolucency per patient. The prevalence of teeth with root canal treatment was very high, broadly equivalent to 2 treatments per patient. Billions of teeth are retained through root canal treatment., (Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

The equid hemoprotozoan parasite Theileria equi is endemic in most regions worldwide. Infection of horses is a cause of significant economic loss due to costs associated with disease and restriction of trade with non-endemic nations. The ability of certain drugs such as imidocarb dipropionate to eliminate persistent T. equi infection and transmission risk is controversial. The anti-protozoal agent ponazuril has been used successfully to treat equine Sarcosystis neurona and Toxoplasma gondii. The hypothesis that ponazuril inhibits replication of T. equi in vitro was tested. T. equi infected equine erythrocyte cultures were treated with ponazuril at multiple concentrations. Cessation of parasite replication was observed over a 5-day period and the degree of inhibition was variable between drug concentrations. Ponazuril inhibited T. equi in erythrocyte culture at all concentrations tested but parasite elimination required at least 500 μg/mL. The high dose of ponazuril required for in vitro inhibition likely limits its ability to control or clear T. equi infection in vivo, however additional research to evaluate related drugs is warranted., (Published by Elsevier B.V.)

Introduction: Anticipation and experience of root canal associated pain is a major source of fear for patients and a very important concern of dentists. Pretreatment, treatment, and posttreatment pain is anticipated, experienced, remembered, and shared by patients. The purpose was to determine the influence of root canal treatment on pain prevalence and severity and estimate the prevalence and severity of pretreatment, treatment, and posttreatment pain in patients receiving root canal treatment., Methods: Defined searching of MEDLINE, Embase, Cochrane, and PsycINFO databases identified 5,517 articles. Systematic review, including title scanning, abstract scanning, full-text review, and quality rating, provided 72 studies for meta-analysis. L'Abbe plots were used to evaluate the influence of root canal treatment on pain prevalence and severity. Pretreatment, treatment, and posttreatment pain prevalence and severity data were analyzed., Results: L'Abbe plots revealed that pain prevalence and severity decreased substantially after treatment. Mean pretreatment, 24-hour posttreatment, and 1-week posttreatment pain prevalences with associated standard deviations were 81 (28%), 40 (24%), and 11 (14%), respectively. Pretreatment, 24-hour posttreatment, and 1-week posttreatment pain severities, on a 100-point scale, were 54 (24%), 24 (12%), and 5 (5%), respectively. Supplemental injections were frequently required (60 [24%])., Conclusions: Pretreatment root canal-associated pain prevalence was high but dropped moderately within 1 day and substantially to minimal levels in 7 days. Pretreatment root canal-associated pain severity was moderate, dropped substantially within 1 day of treatment, and continued to drop to minimal levels in 7 days. Supplemental anesthesia was often required., (Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Extracellular matrix proteins control the formation of the inorganic component of hard tissues including bone, dentin, and enamel. The structural proteins expressed primarily in the enamel matrix are amelogenin, ameloblastin, enamelin, and amelotin. Other proteins, like biglycan, are also present in the enamel matrix as well as in other mineralizing and nonmineralizing tissues of mammals. In addition, the presence of sulfated enamel proteins, and "tuft" proteins has been examined and discussed in relation to enamel formation. The structural proteins of the enamel matrix must have specific protein-protein interactions to produce a matrix capable of directing the highly ordered structure of the enamel crystallites. Protein-protein interactions are also likely to occur between the secreted enamel proteins and the plasma membrane of the enamel producing cells, the ameloblasts. Such protein-protein interactions are hypothesized to influence the secretion of enamel proteins, establish short-term order of the forming matrix, and to mediate feedback signals to the transcriptional machinery of these cells. Membrane-bound proteins identified in ameloblasts, and which interact with the structural enamel proteins, include Cd63 (cluster of differentiation 63 antigen), annexin A2 (Anxa2), and lysosomal-associated glycoprotein 1 (Lamp1). These and related data help explain the molecular and cellular mechanisms responsible for the removal of the organic enamel matrix during the events of enamel mineralization, and how the enamel matrix influences its own fate through signaling initiated at the cell surface. The knowledge gained from enamel developmental studies may lead to better dental and nondental materials, or materials inspired by Nature. These data will be critical to scientists, engineers, and dentists in their pursuits to regenerate an entire tooth. For tooth regeneration to become a reality, the protein-protein interactions involving the key dental proteins must be identified and understood. The scope of this review is to discuss the current understanding of protein-protein interactions of the developing enamel matrix, and relate this knowledge to enamel biomineralization.

Maturation, or meiotic progression, of amphibian oocytes is one of the few physiologically relevant steroid-mediated processes that occurs in the complete absence of transcription from beginning to end. As such, frog oocyte maturation has served as a useful model of nongenomic steroid signaling for many years. Earlier work in Xenopus laevis demonstrated that, although several steroids promoted oocyte maturation in vitro, androgens were the most abundant and potent steroids detected in the serum and ovaries of ovulating frogs. Thus, androgens were likely the primary physiologic regulators of Xenopus oocyte maturation, mediating their actions at least in part via classical androgen receptors expressed in oocytes. The importance of androgens for Xenopus oocyte maturation and ovulation has now been confirmed, as inhibition of androgen production in vivo by blocking CYP17 activity reduced hCG-triggered oocyte maturation and delayed ovulation in female frogs. Taking advantage of the absolute transcription-independence of this androgen-mediated response, selective androgen receptor modulators (SARMs) have been characterized that specifically promote genomic versus nongenomic androgen responses. These include androstenediol and estren, which preferentially promote nongenomic signals, as well as R1881 and 19-nortestosterone, which preferentially promote genomic signaling. Interestingly, the SARMs androstenediol and R1881 signal similarly in mouse oocytes, demonstrating the conserved nature of androgen-mediated maturation in vertebrates. These results suggest that SARMs may serve as useful tools for specifically regulating nongenomic androgen signaling both in vitro and in vivo.

Enamel is a complex bioceramic tissue. In its final form, enamel is a reflection of the unique molecular and cellular activities occurring during organogenesis. From the ectodermal origins of ameloblasts, their gene activity and protein expression profiles exist for the sole purpose of producing a mineralized shell, almost entirely devoid of protein, deposited over the 'bone-like' dentine. The interface between enamel and dentine is referred to as the dentine enamel junction and it is also unique in its biology. This review article is narrow in its scope. We restrict our review to selected advances in our understanding of the genetic, molecular and structural aspects of enamel biology. We present a model of enamel formation that relates gene expression to the assembly of an extracellular protein matrix that in turn controls the structural hierarchy and mechanical aspects of enamel and the tooth organ.

This study investigated the relationship between type of luting cement for artificial crowns and microleakage through dentinal tubules. Standardized preparations were made on intact human premolars, and crowns were made in a base metal alloy using conventional techniques. The castings were randomly assigned to the following luting agent groups: zinc phosphate (ZP), polycarboxylate (PC), glass ionomer (GI), phosphate ester composite resin (GMA/PE), and a composite resin with a NPG-GMA dentin bonding agent (GMA/NPG). Then they were cemented in a standardized manner. The specimens were artificially aged, stained, sectioned, and microleakage occurred through dentinal tubules toward the pulp measured. The rank in order from least to most (best to worst) leakage was GMA/NPG, GI, GMA/PE, PC, and ZP. Material GMA/NPG recorded significantly less leakage than all other materials. Therefore, the results of this study suggest that material GMA/NPG may reduce pulpal sensitivity and pathosis.

The "balanced force" technique was introduced in 1985 and it was reported that the resistance of the dentin, as it circumferentially contacted the flutes of a file in a curved root canal, would be sufficient to override and mask any tendency of the file to straighten during rotational instrumentation. An alternative mechanism based on compressive force and file flexure is presented in this article. In a laboratory study, the apical force necessary to cause files of sizes #10 to #70 to bend and conform to an average canal curvature was determined. These measurements were then related to the apical forces applied to teeth when utilizing the Balanced Force technique in a simulated clinical setting. It was then proposed that the apically directed force necessary to prevent coronal movement of the file and to effect dentinal shearing during counterclockwise rotation placed the file in compression, flexing it to conform to the curvature of the canal. This explanation was consistent with the experimental data for the files used in this study up to size #60 for an average canal curvature and for average instrumentation forces.