Search

This study investigated the impact of coronavirus disease 2019 (COVID‐19) from the perspectives of dental residents in Wuhan, the former COVID‐19 epicenter of China. A survey form was sent to 424 residents in the School of Stomatology, Wuhan University (WHUSS) in September 2020. The form included 23 questions on demographics, study situation of residents during the COVID‐19 outbreak, effect of COVID‐19 on graduates, and status of residents who returned to clinic training. A total of 361 (85%) survey forms were collected. Over 70% of respondents felt anxious during Wuhan lockdown. Most respondents continued studying (94%) mainly through free online resources (79%). The majority reported improvement in didactic knowledge (80%), but the respondents’ perceptions of their clinical skills, especially those in Wuhan, did not change (41%) or worsened (40%) (p< 0.05). Most graduates (88%) reported having found jobs or continued study. Among the 209 responders who returned to clinical training, 52% felt no concern about COVID‐19 infection, 89% thought they were equipped with adequate personal protective equipment (PPE), and 57% indicated that they received sufficient knowledge for preventing COVID‐19 in clinic. Most respondents agreed that the way to gain the knowledge for preventing COVID‐19 in clinic was training at dental school (93%). Although online study has been appreciated by residents, concern about clinical skill learning in the COVID‐19 hardest‐hit area has arisen. Most graduates felt that the impact of COVID‐19 on their immediate postgraduation career was limited. Teaching about infection control in dental schools seemed effective to develop a positive attitude for residents after they returned to clinical training.

A virtual oral health care help line was established to provide consultation and triage for people with dental questions and concerns. Its goal during a pandemic was to keep patients from seeking unnecessary in-person care from emergency departments and urgent care clinics, especially when dental practices were closed or limited to providing essential urgent and emergency oral health care.

Rapid progress has been made in the last decade related to stem cell-mediated pulp–dentin regeneration, from characterization of dental pulp stem cells (DPSCs) to the first-ever reported clinical case in humans. However, many challenges still need to be addressed before such technology can become a common clinical practice; therefore, further rigorous research is needed. Animal study models are very important to test new ideas, concepts, and technologies. This review summarizes and discusses several key animal models that have been utilized to investigate pulp–dentin regeneration. From a tissue regeneration perspective, we categorize the animal model by the location where the regenerated pulp tissue is formed: ectopic, semiorthotopic, and orthotopic. Several animal species are discussed, including mouse, ferret, dog, and miniswine. Mouse is used for ectopic pulp–dentin regeneration in the dorsum subcutaneous space. A commonly tested approach is hydroxyapatite/tricalcium phosphate (HA-TCP) granules model used to observe ectopic pulp–dentin complex formation. The semiorthotopic model includes tooth slices or fragments with which de novopulp regeneration in a root canal space can be tested in the mouse subcutaneous space. For orthotopic pulp regeneration, the canine teeth of ferrets are large enough for such purposes. As nonprimate large animal models, dog and miniswine teeth have many aspects quite similar to those of humans, allowing researchers to perform experiments that mimic clinical conditions in humans. The protocols established and the data obtained from large animal studies may directly relate to and apply to future human studies. Complete orthotopic pulp regeneration has been demonstrated in dogs and miniswine. The use of allogeneic and subpopulations of DPSCs for pulp regeneration, and testing of the periapical disease model and aging model have been performed in miniswine or dogs. In sum, all these animal models will help address challenges that still face pulp regeneration in humans. We need to thoroughly utilize these models to test new ideas, technologies, and strategies before reliable and predictable clinical protocols can be established for human clinical trials or treatment.Impact StatementAnimal models are essential for tissue regeneration studies. This review summarizes and discusses the small and large animal models, including mouse, ferret, dog, and miniswine that have been utilized to experiment and to demonstrate stem cell-mediated dental pulp tissue regeneration. We describe the models based on the location where the tissue regeneration is tested—either ectopic, semiorthotopic, or orthotopic. Developing and utilizing optimal animal models for both mechanistic and translational studies of pulp regeneration are of critical importance to advance this field.

Newer research tools and basic science knowledge base have allowed the exploration of endodontic diseases in the pulp and periapical tissues in novel ways. The use of next generation sequencing, bioinformatics analyses, genome-wide association studies, to name just a few of these innovations, has allowed the identification of hundreds of microorganisms and of host response factors. This review addresses recent advances in endodontic microbiology and the host response and discusses the potential for future innovations in this area.

Diabetes mellitus is a chronic disease with serious health consequences. The association between diabetes and periodontal disease is well documented. However, the progression and healing of endodontic infections in diabetic patients has not been adequately studied. In this review, diabetes mellitus is explored as a potential modulating factor of endodontic pathosis. Recent data on the relationship between the clinical presentation of pulpal and periradicular disease, as well as the outcome of endodontic treatment in diabetic and nondiabetic patients, are presented. Diabetics who present for endodontic treatment, particularly those with periradicular pathosis, may have increased perioperative symptoms. Cases with preoperative periradicular lesions are less likely to be determined successful two years or longer postoperatively if the patient reports a history of diabetes. Studies examining the pathogenesis of periradicular lesions in mouse models with uncontrolled type 1 diabetes suggest that the lesion size may be increased and the animals have increased serious sequelae. Preliminary findings suggest that some bacterial species may be more prevalent in necrotic pulp of diabetic than nondiabetic patients. More studies are needed to further explore the microbiology of endodontic infections and to determine effective treatment strategies in both diabetic and nondiabetic patients.

The authors used a custom-built electronic record system to investigate endodontic diagnostic and treatment outcome data in patients with and without diabetes.

The authors used a custom-built electronic record system to investigate endodontic diagnostic and treatment outcome data in patients with and without diabetes.

Although antibiotics are frequently prescribed to treat endodontic pain patients, there is little evidence from the clinical literature to support this indication. This review focuses on the clinical evidence regarding the efficacy of antibiotics for treating postendodontic pain.

ABSTRACTPCR primers that target the bacterial 16S rRNA genes (or the tufgene for the genus Enterococcus) were used to identify 10 putative bacterial pathogens in root canals with necrotic pulp. In addition, the associations of these microorganisms with symptoms and a history of diabetes mellitus were investigated. Microbial samples from the root canals of 24 teeth with necrotic pulp were included in the study. PCR with universal bacterial primers identified bacterial DNA in 22 specimens; the remaining 2 specimens were from intact teeth that had been traumatized 6 months prior to treatment. PCR with specific primers showed that preoperative symptoms were significantly associated with the presence of Streptococcusspp. (P< 0.001 by chi-square analysis). There was also a nonsignificant trend for symptoms to be associated with Fusobacterium nucleatumand Porphyromonas gingivalis(odds ratio, >2) and for diabetes mellitus to be associated with P. gingivalisand Porphyromonas endodontalis(odds ratio, >2). Cloning and sequencing of the universal PCR product in one specimen revealed the presence of an organism related to the genus Olsenella, which has not previously been described in endodontic infections.

Objective.The aim of this study was to investigate the effects of enamel matrix derivative (EMD) on gene expression of collagen α1 (I), osteocalcin, prostaglandin G/H synthase 2 (PGHS-2), interleukin-6, and insulin-like growth factor I in primary mouse osteoblasts. Study Design.Primary osteoblasts were digested from 6- to 8-day-old mouse calvaria. Cells were divided into 4 groups and cultured for 24, 48, and 72 hours with a serum-free modified eagle medium as negative control, modified eagle medium with 25 μg/mL EMD, modified eagle medium with 100 μg/mL EMD, and modified eagle medium plus 10% fetal bovine serum as positive control. Gene expression was determined by Northern blot and reverse transcription polymerase chain reaction analysis. Result.EMD enhanced collagen I, interleukin-6, and PGHS-2 expression and did not stimulate the expression of osteocalcin and IGF-I. Conclusion.These results indicate that EMD might regulate certain gene expression during periodontal tissue regeneration. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2001;91:95-100)

What the generalist needs to know. Leading off the specialtysection is a report on what’s new in prosthodontic care followed by articles on treating a patient with palatal Kaposi’s sarcoma; combining endodontic, periodontic and restorative care; and treating xerostomia.

What the generalist needs to know. Leading off the specialtysection is a report on what’s new in prosthodontic care followed by articles on treating a patient with palatal Kaposi’s sarcoma; combining endodontic, periodontic and restorative care; and treating xerostomia.

The relationship of apical periodontitis (AP) and type 2 diabetes mellitus (T2DM) is poorly studied in large populations. The aims of this study were to determine if there is an independent association between AP and T2DM in a large hospital network after controlling for confounding variables, as well as to determine if glycated hemoglobin levels were independently associated with AP.

Theoretical simulations of temperature elevations in root dentin are performed to evaluate, how heating protocols affect the efficacy of using erbium, chromium; yttrium, scandium, gallium, garnet (Er,Cr;YSGG) pulsed lasers for bacterial disinfection during root canal treatments. The theoretical models are generated based on microcomputer tomography (microCT) scans of extracted human teeth. Heat transfer simulations are performed using the Pennes bioheat equation to determine temperature distributions in tooth roots and surrounding tissue during 500 mW pulsed Er,Cr;YSGG laser irradiation on the root canal for eradicating bacteria. The study not only determines the heat penetration within the deep dentin but also assesses potential thermal damage to the surrounding tissues. Thermal damage is assumed to occur when the tissue is subject to a temperature above at least 47 °C for a minimum duration of 10 s. Treatment protocols are identified for three representative tooth root sizes that are capable of maintaining elevated temperatures in deep dentin necessary to eradicate bacteria, while minimizing potential for collateral thermal tissue damage at the outer root surfaces. We believe that the study not only provides realistic laser heating protocols for various tooth root geometries but also demonstrates utility of theoretical simulations for designing individualized treatments in the future.