teeth

Abstract: Objectives: Differences in the mineral concentration (MC) level of dental enamel may represent a precursor of white spot lesions adjacent to fixed orthodontic brackets. The aim of the current in vitro study was to compare the MC level central, occlusal and cervical to orthodontic attachments. Methods and materials: A total of 16 enamel blocks were obtained from sound human premolar samples extracted for orthodontic reasons. The buccal portion of the dental enamel blocks was divided into central, occlusal, and cervical regions and then imaged and measured to calculate the level of MC using quantitative X-ray microtomography methods (XMT) at each site....

Abstract: The coronal portion of the developing upper third molar may be impacted by the developing roots of the second molar. At the relevant age – roughly from 10 to 13 years – both organs are largely soft tissues when and where they collide. It is obviously not possible to obtain tissue from both teeth whilst they are developing, but a frequent after-effect of such collisions is extraction of the third molar....

Abstract: Starting from scratch, if one wanted to correlate light microscopical (LM) and X-ray microtomographic (XMT, micro-CT) findings from the mineralized tissues - bone and calcified cartilage in the skeleton and dentine, enamel, and cementum in teeth - one could simply examine the same, resin embedded sample with at least one flat surface by confocal scanning reflection and/or fluorescence light microscopy and XMT. However, we are frequently presented with ready-made ‘ground’ sections mounted in Canada balsam or DPX on 25mm wide ~1mm thick glass slides with 0....

Abstract: Healthy connective tissues are covered and protected by an epithelium. The single unavoidable exception concerns cementum and dentine at the neck of a tooth after the epithelial attachment migrates past the enamel. Carious lesions break this barrier and microbial invasion via dentine and pulp leads to pulpitis, osteomyelitis and extraction. Similarly, tooth loss from periodontal disease may leave infected bone. Dental implants may thus be placed in prejudiced bone. In the context of this symposium, therefore, the peri-implant disease may be nucleated before the outset....

Abstract: Artificial teeth have several advantages in preclinical training. The aim of this study is to three-dimensionally (3D) print accurate artificial teeth using scans from X-ray microtomography (XMT). Extracted and artificial teeth were imaged at 90 kV and 40 kV, respectively, to create detailed high contrast scans. The dataset was visualised to produce internal and external meshes subsequently exported to 3D modelling software for modification before finally sending to a slicing program for printing....

Abstract Objectives:: The objective of this in vitro study was to quantify the amount of mineral change in demineralized dentin at pH 5.5 after the application of dental varnishes containing fluoride with casein phosphopeptide-amorphous calcium phosphate, fluoride and bioglass, or fluoride alone. Methods and materials:: A total of 12 extracted human sound mandibular premolar root samples were coated with an acid-resistant varnish, leaving a 2 × 3 mm window at the outer root surface....

Abstract: Fracture of nickel-titanium (NiTi) endodontic files is an uncommon but potentially damaging occurrence during root canal preparation. If the broken portion of the file remains inside the tooth canal it can prevent complete preparation of the root canal with consequent negative impact on treatment outcomes. Removal of file fragment from the tooth canal is currently a mechanical process, which due to the limited working space and restricted view can lead to further problems including perforation of the tooth....