Dentists' perceptions of providing care to community-dwelling older people.

Objectives: This study explored the attitudes of New Zealand (NZ) general dental practitioners (GDPs) towards older adults living within the community and the barriers and difficulties caring for their oral health needs.

Background: Adults are living longer and retaining teeth. Their dentitions are complex and alongside their dental needs, older adults often experience age-related systemic disease or decline.

Students' experience and perceptions of undergraduate endodontic education in New Zealand.

This study investigated the clinical experience and perceptions of New Zealand graduating dental students (2019 and 2020) towards endodontic teaching and their clinical learning outcomes using an online survey and clinical scenarios. Quantitative data were analysed using SPSS software, and qualitative data were analysed thematically. Responses were similar for both cohorts (response rates 74%, 2019; 73%, 2020).

The effects of chelation on the intratubular penetration depth of mineral trioxide aggregate.

The penetration depth and extent of mineral trioxide aggregate (MTA) crystallisation into dentinal tubules at 2, 4 and 6 weeks after chelation and MTA obturation were investigated. Standardised 12 mm human root specimens (45) were prepared with NiTi rotary files using 4% NaOCl irrigation. They were randomly allocated to three irrigants (n = 15: 4% NaOCl, 15% ethylenediaminetetraacetic acid or Edgemix) and obturated with sodium fluorescein tagged ProRoot MTA.

De novo-designed transmembrane domains tune engineered receptor functions.

De novo-designed receptor transmembrane domains (TMDs) present opportunities for precise control of cellular receptor functions. We developed a de novo design strategy for generating programmed membrane proteins (proMPs): single-pass α-helical TMDs that self-assemble through computationally defined and crystallographically validated interfaces. We used these proMPs to program specific oligomeric interactions into a chimeric antigen receptor (CAR) that we expressed in mouse primary T cells and found that both in vitro CAR T cell cytokine release and in vivo antitumor activity scaled linearly with the oligomeric state encoded by the receptor TMD, from monomers up to tetramers.

T Cell Activation Machinery: Form and Function in Natural and Engineered Immune Receptors.

The impressive success of chimeric antigen receptor (CAR)-T cell therapies in treating advanced B-cell malignancies has spurred a frenzy of activity aimed at developing CAR-T therapies for other cancers, particularly solid tumors, and optimizing engineered T cells for maximum clinical benefit in many different disease contexts. A rapidly growing body of design work is examining every modular component of traditional single-chain CARs as well as expanding out into many new and innovative engineered immunoreceptor designs that depart from this template. New approaches to immune cell and receptor engineering are being reported with rapidly increasing frequency, and many recent high-quality reviews (including one in this special issue) provide comprehensive coverage of the history and current state of the art in CAR-T and related cellular immunotherapies.

Bonding strengths to porcelain: An study of ultrasonic and conventional tooth preparation and etching.

Objective: To compare the bond strength of porcelain to enamel and dentin preparations finished with either ultrasonic instruments or diamond burs, with or without acid etching.

Materials And Methods: A total of 140 extracted bovine incisor teeth were divided into two groups, enamel and dentin. A split tooth model was employed: each tooth having a randomly allocated combination of diamond burs, ultrasonic instrument, etching, and no etching treatments on their labial surface.

Lubrication during root canal treatment.

Lubrication is involved in all root canal treatment phases, from dental dam placement to canal obturation. Most often associated with instrumentation, lubrication is required to facilitate the mechanical action of hand/rotary files and to help emulsify and suspend the debris produced. Aqueous irrigation solutions such as sodium hypochlorite and ethylenediaminetetraacetic acid (EDTA) should be regarded as lubricants, but paste-type substances are marketed specifically for this purpose.

Crack Formation Following Root-End Preparation in Roots with the Butterfly Effect.

Objective: To investigate apical cracks in roots that exhibit the butterfly effect and that have undergone apical resection and ultrasonic root-end cavity preparation. The effect of the obturation material was also studied.

Methods: Forty extracted single-rooted teeth were decoronated at the cemento-enamel junction.

Eyesight: a study of the staff of a dental school.

Objectives/aims: The aim was to investigate the vision of all 90 dentally qualified staff at a dental school.

Materials And Methods: Ethical approval was obtained and a questionnaire-based survey conducted. Data were screened and analysed using Stata 13.

Sealer penetration and adaptation in root canals with the butterfly effect.

The butterfly effect is a phenomenon seen in some roots and is related to density of dentinal tubules. The aim was to investigate penetration depth and adaptation quality of root canal sealers and ProRoot MTA into bucco-lingual and mesio-distal aspects of roots with and without the effect. One hundred and twenty teeth were decoronated at the cemento-enamel junction.

Effectiveness of Disposable (Single-use) Tips for Dental Air-water Syringes.

Background: Single-use dental syringe (SUS) tips eliminate cross-infection risks. Many dental materials are moisture sensitive; therefore bonding could be affected by remaining moisture from SUS tips.

Methods: An air-water syringe was calibrated to 50 PSI and the air pressure measured.

Electronic apex locators may be better at determining endodontic working length than radiographs and could reduce patient radiation exposure.

Article Title And Bibliographic Information: Clinical efficacy of electronic apex locators: Systematic review. Martins JNR, Marques M, Mata A, Carames J.J Endod 2014;40(6):759-77.

Undergraduate endodontic teaching in New Zealand: students' experience, perceptions and self-confidence levels.

The aim was to investigate undergraduate students' experiences, perceptions of future practice and self-rated confidence levels across endodontic tasks. After ethical approval, a survey involved all fourth and fifth year students. Quantitative data were analysed in SPSS version 20.

Antibacterial properties of root canal lubricants: a comparison with commonly used irrigants.

The aim was to assess in vitro the antibacterial activity of 10 root canal lubricants. K-Y Jelly personal lubricant, RC-Prep, File-Eze, File-Rite, EndoPrep Gel, Endosure Prep Crème 15%, Prep-Rite, Glyde, SlickGel ES and Alpha Glide were selected and compared in their antimicrobial properties to seven irrigants. Serial dilutions of each agent in tryptic soy broth were inoculated with either Enterococcus faecalis or Pseudomonas aeruginosa and incubated at 37C for 24 h.

Investigation of dentin hardness in roots exhibiting the butterfly effect.

Introduction: Most vertical root fractures occur in root canal treated teeth, and they usually run in a buccolingual direction. The butterfly effect is an optical phenomenon seen in some sections of tooth roots. The aim was to investigate the microhardness of dentin in mesiodistal and buccolingual cross sections of roots exhibiting the effect.

Crack formation on resected root surfaces subjected to conventional, ultrasonic, and laser root-end cavity preparation.

Objective: The aim of this study was to evaluate cracks on root ends following resection and cavity preparation with a laser and two established techniques.

Background Data: If root canal treatment of a tooth fails, an apicoectomy operation may be indicated. Three millimeters of the root tip is resected and a cavity of similar depth with parallel walls is cut to receive a root-end filling.

Accuracy of the Dentaport ZX apex locator for working length determination when retreating molar root canals.

The aim of this study was to evaluate the accuracy of the Dentaport ZX apex locator for working length determination during root canal retreatment of mandibular molars. Fifteen extracted mandibular first molars with separate mesial canals and apical foraminae and one distal canal were selected. The mesiobuccal and distal canals were investigated; the length with the file tip at the major diameter was defined as the tooth length (TL).

Root canal treatment and prevalence of apical periodontitis in a nigerian adult subpopulation: a radiographic study.

Purpose: To evaluate the frequency, distribution and quality of root canal treatment in an adult Nigerian subpopulation and to determine the prevalence of apical periodontitis.

Materials And Methods: The periapical status and length of root fillings of 756 patients attending Obafemi Awolowo University Teaching Hospital, Ile-Ife, Nigeria for the first time were evaluated using full mouth periapical radiographs. The length of the root canal filling was considered 'adequate' if it was ≤ 2 mm from the radiographic apex, 'under-filled' if it was > 2 mm short of the apex, and 'overfilled' if filling material extended beyond the radiographic apex.

Dentists make larger holes in teeth than they need to if the teeth present a visual illusion of size.

Background: Health care depends, in part, on the ability of a practitioner to see signs of disease and to see how to treat it. Visual illusions, therefore, could affect health care. Yet there is very little prospective evidence that illusions can influence treatment.

The butterfly effect: an investigation of sectioned roots.

Introduction: The butterfly effect is an optical phenomenon seen in some sections of tooth roots. The aim of this work was to investigate the density of dentinal tubules in mesiodistal and buccolingual cross-sections of roots exhibiting the butterfly effect and to determine if the effect is featured throughout the length of roots and is age related.

Methods: Thirty extracted single-rooted teeth were allocated to the following groups according to patient age: group 1: 15-24 years, group 2: 25-44 years, and group 3: 45 years and over.

Infection of apical dentin and root-end cavity disinfection.

Introduction: The purpose of this study was to assess Enterococcus faecalis penetration into the dentin of the apical 3 mm and bacterial death after the application of either chlorhexidine or laser to root-end cavities.

Methods: Root canals of 60 single-rooted teeth were prepared. In part 1, cementum was removed semicircumferentially from 21 roots, and the smear layer was removed from 15 roots using 17% EDTA/cetrimide.

The effect of ultrasonic instruments on the quality of preparation margins and bonding to dentin.

Statement Of The Problem: Ultrasonic instruments have recently been developed for finishing crown preparations. They are successful in accessing difficult areas on the preparation margin, but their effects on the dentin surface and on bond strength are contradictory.

Purpose: The aim was to evaluate the condition of crown preparation margins finished using new ultrasonic instruments and to assess their effects on dentin bond strength.

Avulsion and replantation of a primary incisor tooth.

Avulsion of a primary tooth is a serious dental trauma, and the guidelines of the International Association of Dental Traumatology and textbooks in paediatric dentistry do not recommend replantation. Such management can result in severe damage to the supporting structures, and together with avulsion itself is commonly associated with developmental disturbances of the permanent tooth. We report the case of replantation in a 9-month-old child with a successful outcome, in a unique situation where conditions were optimal and careful long-term follow up was possible.