627
1,206.72
1.92
648

Publication History View all

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The effects of cryopreservation on mesenchymal stem cell (MSC) phenotype are not well documented; however this process is of increasing importance for regenerative therapies. This study examined the effect of cryopreservation (10% dimethyl-sulfoxide) on the morphology, viability, gene-expression and relative proportion of MSC surface-markers on cells derived from rat adipose, bone marrow and dental pulp. Cryopreservation significantly reduced the number of viable cells in bone marrow and dental pulp cell populations but had no observable effect on adipose cells. Flow cytometry analysis demonstrated significant increases in the relative expression of MSC surface-markers, CD90 and CD29/CD90 following cryopreservation. sqRT-PCR analysis of MSC gene-expression demonstrated increases in pluripotent markers for adipose and dental pulp, together with significant tissue-specific increases in CD44, CD73 and CD105 following cryopreservation. Cells isolated from different tissue sources did not respond equally to cryopreservation with adipose tissue representing a more robust source of MSCs.
    Cryobiology 08/2014; 69(2). DOI:10.1016/j.cryobiol.2014.08.003
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Dental tissue infection and disease result in acute and chronic activation of the innate immune response, which is mediated by molecular and cellular signaling. Different cell types within the dentin-pulp complex are able to detect invading bacteria at all stages of the infection. Indeed, at relatively early disease stages, odontoblasts will respond to bacterial components, and as the disease progresses, core pulpal cells including fibroblasts, stems cells, endothelial cells, and immune cells will become involved. Pattern recognition receptors, such as Toll-like receptors expressed on these cell types, are responsible for detecting bacterial components, and their ligand binding leads to the activation of the nuclear factor-kappa B and p38 mitogen-activated protein (MAP) kinase intracellular signaling cascades. Subsequent nuclear translocation of the transcription factor subunits from these pathways will lead to proinflammatory mediator expression, including increases in cytokines and chemokines, which trigger host cellular defense mechanisms. The complex molecular signaling will result in the recruitment of immune system cells targeted at combating the invading microbes; however, the trafficking and antibacterial activity of these cells can lead to collateral tissue damage. Recent evidence suggests that if inflammation is resolved relatively low levels of proinflammatory mediators may promote tissue repair, whereas if chronic inflammation ensues repair mechanisms become inhibited. Thus, the effects of mediators are temporal context dependent. Although containment and removal of the infection are keys to enable dental tissue repair, it is feasible that the development of anti-inflammatory and immunomodulatory approaches, based on molecular, epigenetic, and photobiomodulatory technologies, may also be beneficial for future endodontic treatments.
    Journal of endodontics 04/2014; 40(4):S46–S51. DOI:10.1016/j.joen.2014.01.021
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim of this pilot study was to analyze the interfurcal bone height in relation to the possible need for subsequent sinus floor elevation in patients with advanced periodontitis and furcation involvement of first and/or second maxillary molars. Seventeen dentate patients, who received cone beam computed tomography (CBCT) for detailed preoperative diagnosis and planning of surgical interventions at periodontally involved maxillary molars (17 first and 15 second molars), were consecutively recruited for the study. The minimal bone height in the interfurcal region was measured from CBCT and related to furcation involvement, residual bone above the root tips, and the clinical probing pocket depth (PPD). The minimal interfurcal bone height measured 4.1 ± 2.6 mm on average with 75% of maxillary molars having ≤6 mm and almost 60% having only ≤4 mm bone height left below the sinus floor. A higher risk for reduced interfurcal bone height of ≤4 mm was given when residual PPD of ≥6 mm was remaining at two or more tooth sites (OR 0.10; 0.11). The majority of periodontally involved maxillary molars had a substantially reduced interfurcal bone height, particularly with at least two sites with residual PPD ≥ 6 mm. This was a predictor for a subsequent need for sinus floor elevation when tooth replacement with a dental implant is desired.
    Clinical Oral Implants Research 10/2013; DOI:10.1111/clr.12275
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objective To evaluate reinforced glass-ionomer restorations which had been placed in a general dental practice more than five years previously.Method Patients who were identified as having received reinforced one or more reinforced glass-ionomer restorations were invited to attend for an examination of their restorations using scientific evaluation criteria, by one independent examiner and the dentist who owned the practice.Results Forty-two restorations were assessed, their mean age being 7 years and 9 months, in patients of mean age 57 years: 86% achieved an A rating for anatomic form, 69% A for marginal integrity, 81% A for surface roughness and 2% A for colour match.Conclusions The restorations which were assessed were found to be performing satisfactorily at periods of over five years. However, the proportion of the total number of reinforced glass-ionomer restorations placed in the participating dental practice which this represents is not known.
    British dental journal official journal of the British Dental Association: BDJ online 09/2013; 215(6):E9. DOI:10.1038/sj.bdj.2013.880
  • [Show abstract] [Hide abstract]
    ABSTRACT: To determine whether the use of oval posts increases fracture resistance of root canal treated teeth with oval-shaped canals. Extracted mandibular premolars with similar dimensions were decoronated. After root canal treatment, standardized post space preparations were performed to simulate the presence of oval-shaped root canal morphologies. Specimens were randomly assigned to 3 groups (n = 3 × 24). In group SFP (small fiber post), circular posts with a cervical diameter of 1.5 mm were used without additional form-congruent post space preparation. In group LFP (large fiber post), a circular post space preparation was performed to adapt posts with a cervical diameter of 1.9 mm. In group OFP (oval fiber post), oval posts with a long cervical diameter of 1.9 mm and short cervical diameter of 1.3 mm were utilized without additional post space preparation. Posts were cemented with dual-cure resin. All specimens were restored with standardized direct composite crowns. After thermo-mechanical loading in a computer-controlled masticator, all specimens underwent fracture resistance testing. Means and standard deviations were calculated. Data were analyzed using the Kruskal-Wallis test (α = 0.05). The highest mean fracture load was observed in group OFP (273N ± 51), the lowest in group LFP (258N ± 72). Kruskal-Wallis indicated no significant differences in fracture resistance among the three experimental groups. Within the limitations of this laboratory study, oval posts did not reveal increased fracture resistance of root canal-treated premolars with oval-shaped root canals compared with circular posts.
    Dental Traumatology 09/2013; DOI:10.1111/edt.12060
  • [Show abstract] [Hide abstract]
    ABSTRACT: This study reported the results at five years of fixed-fixed all-ceramic bridges, constructed in a yttria oxide stabilized tetragonal zirconium oxide polycrystal (Y-TZP) substructure, placed in adult patients in UK general dental practices. Four UK general dental practitioners recruited patients who required fixed bridgework and, after obtaining informed written consent, appropriate clinical and radiographic assessments were completed. The teeth were prepared and bridges constructed in accordance with the manufacturer's instructions. Each bridge was reviewed annually within 3 months of the anniversary of its placement by a calibrated examiner, together with the clinician who had placed the restoration, using modified USPHS criteria. Of the 41 bridges originally placed, 33 bridges were examined at five-years. All Y-TZP frameworks were intact and no bridge retainers had debonded. Eight chipping fractures in the veneering ceramic were noted over the five year period. In five cases the patients were unaware of these and these cases were polished. Of the remaining three cases, in one a repair was attempted but was unsuccessful, but the bridge remained in satisfactory service. However, in the case involving a chipping fracture of the mesial-incisal angle of a central incisor, it was considered that replacement of the bridge was necessary. 97% (n=32) of the 33 Lava Y-TZP fixed-fixed bridges, evaluated in patients attending UK general dental practices, were found to be performing satisfactorily. The use of Y-TZP frameworks holds promise.
    Journal of dentistry 08/2013; 41(11). DOI:10.1016/j.jdent.2013.08.007
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The ability of single-file, reciprocating instruments to remove inorganic debris is uncertain. By using micro-computed tomography (microCT), this study compared the 3-dimensional distribution, quantity, and density of remaining inorganic debris in the mesial root of mandibular molars after instrumentation. A single reciprocating file was compared with a multifile rotary instrumentation technique. Teeth were selected for instrumentation using reciprocating or rotary instruments (n = 19). Teeth were scanned using microCT before and after instrumentation. Through shape recognition and superimposition image analysis techniques, remaining inorganic tissue debris was identified, quantified, and visualized 3-dimensionally, mapping debris to its location. The use of a density phantom enabled the debris density to be calculated, giving a measure of compactness. After single-file instrumentation, an average of 19.5% debris remained in the canal compared with 10.6% with the multifile technique (P = .01) and at an average density of 1.60 g/m(3) compared with 1.55 g/m(3) for the multifile system (P > .05). Isthmuses, protrusions, and irregularities in the canal wall were repeatedly seen at the locations of debris accumulation. In canals with a high prevalence of isthmuses and protrusions, using multifile rotary systems may be preferred over reciprocating files because it can yield cleaner canals with less debris accumulation.
    Journal of endodontics 08/2013; 39(8):1067-70. DOI:10.1016/j.joen.2013.04.003
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Introduction: The most reliable and frequently applied method for identification of fire victims is comparative dental radiography. Forensic investigators are often confronted with fragmented and isolated remains, frequently removed from their anatomical position. Whilst the heat-induced dimensional and morphological changes in bone have been previously studied, precise data for heat-induced changes of human teeth is still lacking. Objective: The aim of this study was to obtain quantitative micro-CT data to evaluate the three-dimensional shrinkage and shape preservation of human teeth to provide an improved understanding on heat-induced alterations of dental tissues. Materials & Methods: High-resolution micro-CT scans and digital radiographs were carried out on 66 freshly extracted human teeth before and after 30 minute exposure to temperatures of 400 - 1000°C. Image analysis was performed using 3D Slicer and ImageJ imaging packages. Results: The average volumetric shrinkage ranged between 4.78% (at 400°C) and 32.53% (at 1000°C). A major increase in shrinkage occurs between 700°C and 800°C, while no significant statistical difference (ANOVA post-hoc LSD, α <0.05) was found between lower temperature groups. Tooth morphology was generally well preserved even at high temperatures, in contrast to observation made for burned bone, where warping and strong deformation can occur. Conclusions: The results of this micro-CT study add relevant information on shape preservation and allow forensic investigators to account for heat-induced alterations of size, eventually facilitating the odontological identification process in cases where only isolated teeth or dental fragments are present.
    07/2013; 1(3). DOI:10.1016/j.jofri.2013.05.003
  • [Show abstract] [Hide abstract]
    ABSTRACT: OBJECTIVE: Diclofenac is an effective and well-tolerated nonsteroidal anti-inflammatory drug (NSAID) frequently used in the treatment of acute pain. Marketed formulations for parenteral administration usually contain 75 mg/3 mL of diclofenac sodium, which provide limited dosing flexibility, and are usually given intramuscularly. METHODS: We present a randomized, double-blind, active comparator- and placebo-controlled, parallel-group phase III multicenter study, investigating efficacy and tolerability of a new 1 mL-volume formulation of diclofenac sodium (25, 50 or 75 mg) containing hydroxypropyl-β-cyclodextrin (HPβCD) as a solubility enhancer. This low-volume formulation allows subcutaneous (SC), in addition to intramuscular (IM) administration. Patients developing moderate-to-severe pain (≥ 50 mm on Visual Analogue Scale) after third molar extraction under local anesthesia were randomized to one of the 4 SC injections: 25 mg diclofenac HPβCD (n = 77), 50 mg diclofenac HPβCD (n = 76), 75 mg diclofenac HPβCD (n = 78), or placebo (n = 75). RESULTS: Mean pain intensity difference at 1.5 hours postdose (primary endpoint) was higher in all diclofenac-treated groups than placebo group. The adjusted means (95% CI) were 36.5 (31.7 to 41.2) in diclofenac 25 mg group, 37.3 (32.6 to 42.1) in diclofenac 50 mg group, 37.7 (33.0 to 42.4) in diclofenac 75 mg group, and 12.3 (7.44 to 17.1) in placebo group. Both 25 and 50 mg doses of diclofenac produced significantly greater pain relief than placebo (P < 0.001 in both comparisons). CONCLUSION: Single SC doses of diclofenac HPβCD of 25 and 50 mg are effective and well tolerated for relieving pain compared with placebo.
    Pain Practice 05/2013; 14(4). DOI:10.1111/papr.12082
  • [Show abstract] [Hide abstract]
    ABSTRACT: Dental materials which are user friendly make clinicians' lives simpler by facilitating their placement in patients' teeth: accordingly, the handling of materials is of relevance to the clinician. This paper traces the history of product handling evaluations and practice-based research by the PREP Panel, a group of practice-based researchers based in the UK. Clinical Relevance: The ease of handling of dental materials is important in dental practice, given that practitioners may find that a material which is difficult to handle leads to suboptimal clinical results.
    Dental update 05/2013; 40(4):339-41.
Information provided on this web page is aggregated encyclopedic and bibliographical information relating to the named institution. Information provided is not approved by the institution itself. The institution’s logo (and/or other graphical identification, such as a coat of arms) is used only to identify the institution in a nominal way. Under certain jurisdictions it may be property of the institution.