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A textile-based reaction system for new peroxidase reactions in non-native media was implemented. The epoxidation of cyclohexene by the commercial peroxidase MaxiBright® was realized with the textile-immobilized enzyme in an adapted liquid-liquid two-phase reactor. A commercially available polyester felt was used as low-price carrier and functionalized with polyvinyl amine. The covalent immobilization with glutardialdehyde lead to an enzyme loading of 0.10 g enzyme /g textile . The textile-based peroxidase shows a high activity retention in the presence of organic media. This catalyst is shown to enable the epoxidation of cyclohexene in various solvents as well as under neat conditions. A model reactor was produced by 3D printing which places the textile catalyst at the interphase between the liquid reaction phase and the product extracting solvent., Competing Interests: Declaration of Competing Interest There are no conflicts to declare., (Copyright © 2020 Elsevier Inc. All rights reserved.)

This study elucidates the role of interleukin-1 (IL-1) in developing periradicular lesions in immunocompetent and immunocompromised (human immunodeficiency virus/acquired immune deficiency syndrome) hosts. Eight cats were immunosuppressed with steroids before infection with feline immunodeficiency virus (FIV). Eight uninoculated cats served as controls. Periradicular lesions were induced around the canine teeth. At 1 and 4 wk periradicular exudate was sampled via the root canals. IL-1beta levels were measured with ELISA. Data were analyzed using the Mann-Whitney U test and the Wilcoxon signed rank test. Statistically significant differences existed in cytokine levels between the FIV and non-FIV groups (p < 0.001). Cytokines were below detectable levels in the FIV group. A significant decrease in IL-1beta levels at 4 wk compared with 1 wk occurred in the non-FIV group (p < 0.05). In conclusion decreased IL-1beta production was obtained in the FIV group. In the non-FIV group decreases in IL-1beta levels were encountered at the chronic stage of the periradicular lesion compared with the acute stage.

This study was designed to induce rapid progression of the feline immunodeficiency virus (FIV) infection in cats. Predictably inducing the FIV disease state in the cat would yield an excellent tool to study endodontic disease processes under immunosuppressed conditions. Eight cats were immunosuppressed with steroids before infection with FIV. Another eight cats, age- and sex-matched littermates, served as uninoculated seronegative controls. Complete blood counts were taken for 10 mo in the FIV group, and 10 wk in the control group, including lymphocyte subsets. ELISAs were used to detect FIV infection. Statistical analysis was performed with generalized estimating equation models. All cats were positive at one point in time. The FIV group had significantly lower peripheral blood CD4+ counts compared with the control group. Therefore the FIV model presented gives the desired outcome and simulates what occurs in human immunodeficiency virus infection.

Histological and morphometric assessment of periradicular wound healing was made after the use of a bioresorbable membrane over a buccal dehiscence. The third and fourth premolar teeth of nine dogs were resected and buccal defects created. Teeth were assigned randomly to the membrane or control group. One tooth in each quadrant received a membrane, covering both roots. The other tooth received no further treatment and served as a control. The animals were killed and specimens were assessed at two time periods: 9 wk and 27 wk. The 27-wk membrane group exhibited significantly more (p = 0.004) connective tissue height than the control group or either of the 9-wk groups. The amount of regenerated alveolar bone was significantly greater for the 27-wk membrane group than for the control (p = 0.001) and 9-wk groups. Mean junctional epithelium measurements were significantly greater (p = 0.012) for the control. The use of a bioresorbable membrane enhances bone regeneration when a buccal defect exists at the time of periradicular surgery.

Collagen protein synthesis by osteoblasts is influenced by transforming growth factor-beta (TGF-beta 1) and is essential to bone formation. The effectiveness of TGF-beta 1 depends on efficient delivery of the growth factor to target cells, adequate binding to cell surface receptors, and an optimum environment for promotion of collagen synthesis. The effects of calcium hydroxide (Ca(OH)2), TGF-beta 1, and Ca(OH)2/TGF-beta 1 co-administration on total protein, collagen protein, and noncollagen protein synthesis by early (subculture I) and late (subculture V) osteoblast cultures were tested. TGF-beta 1 significantly increased all protein synthesis in subculture I osteoblasts (p = 0.001; p < 0.001; p = 0.019). Ca(OH)2/TGF-beta 1 co-administration significantly increased total protein and collagen protein levels in subculture I osteoblasts as well (p = 0.048; p = 0.012). TGF-beta 1 increased total protein and collagen protein synthesis significantly in subculture V cells (p = 0.025; p = 0.01). These data indicate that co-administration of Ca(OH)2 and TGF-beta 1 enhances collagen synthesis by osteoblasts and may have implications for the clinical setting.

This paper explores the potential contributions to patients, the practice, the endodontist, and the dental hygienist that may be realized by the employment of one or more dental hygienists to serve as endodontic co-therapists in the delivery of endodontic treatment. An endodontic co-therapist is an individual who participates with the endodontist in the assessment, planning, implementation, and evaluation of treatment much like the periodontal co-therapist relationship that exists between periodontists and dental hygienists. Dental hygienists are ideal individuals for this role because of their education in basic, clinical, and behavioral sciences. Suggestions are provided for which services could be delegated by the endodontist to the dental hygienist during each phase of care. Advantages of this contemporary approach to the delivery of endodontic treatment are also addressed.

The effectiveness of sealer placement and its distribution in the prepared root canal system by an energized ultrasonic file was evaluated in vivo. One hundred patients had sealer placed into prepared root canals with either the master gutta-percha cone or an ultrasonic file. Before placement of sealer with the file, canals were irrigated, debrided, and flushed with water for 10 s and an energized #20 ultrasonic file at 1.0 mm from the working length. Canals were obturated with gutta-percha using lateral condensation, and evaluations were based on the presence or absence of sealer-filled accessory canals. Chi-square analysis showed that a statistically significant difference existed in the number of radiographically visible accessory canals filled when the ultrasonic file was used to place the sealer.

A survey was conducted to determine the frequency and popularity of contemporary methods used in endodontic retreatment to remove intraradicular posts. Opinions and rationales were also sought for the choice of surgical management instead of nonsurgical retreatment. A questionnaire was sent to 571 active Diplomates of the American Board of Endodontics with 324 members responding (56.7%). Hand instruments, such as hemostats or special forceps, were the most commonly used, often in conjunction with ultrasonic or sonic vibration to loosen the post or break down the cement interface. A wide range of rationales was identified for the use of surgical retreatment methods, with failure to remove the post after reasonable nonsurgical efforts being the most often cited.

The removal of an intraradicular post is frequently part of retreatment and the fabrication of a new coronal restoration. This article highlights the use of a post puller for safe and effective removal of an intraradicular post in conjunction with retreatment.