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The Journal of Prosthetic Dentistry Oct 2023Deep margin elevation is a solution to the problem of localized subgingival margins when preparing a tooth for direct, semidirect, or indirect restorations. The...
Deep margin elevation is a solution to the problem of localized subgingival margins when preparing a tooth for direct, semidirect, or indirect restorations. The technique focuses on the local isolation of the deep margin by using a modified circumferential matrix. An evolution of the technique is presented, the matrix-in-a-matrix technique, to facilitate the isolation and fit of the subgingival matrix by adding a sectional band inside the circumferential matrix and packing Teflon tape between the 2 bands. Resective surgeries, invasive restorative procedures, and even sometimes extractions can all potentially be avoided by this modified deep margin elevation, allowing ideal conditions for scanning or impression making.
PubMed: 34961611
DOI: 10.1016/j.prosdent.2021.11.021 -
Hand Surgery & Rehabilitation Apr 2024Longitudinal melanonychia (LM) is a pigmented band extending from the matrix to the distal edge of a nail. It is caused by increased production of melanin within the...
Longitudinal melanonychia (LM) is a pigmented band extending from the matrix to the distal edge of a nail. It is caused by increased production of melanin within the matrix, and integration into the nail plate. The origin of this production is usually benign, due to activation, hyperplasia or proliferation of melanocytes normally present in the matrix. In some cases, however, LM is the manifestation of a subungual melanoma, the diagnosis of which must be made early. Biographical, clinical and dermoscopic criteria make it possible to suspect melanoma and decide whether to perform biopsy. None of these criteria, however, are specific and definitive diagnosis requires pathologic examination of a matrix biopsy. The biopsy technique should enable reliable histological study while limiting the risk of secondary nail dystrophy. Initial resection should ideally involve the entire lesion. Complete elevation of the nail plate enables the lesion to be precisely located. Lesions up to 3 mm can be removed by longitudinal resection biopsies without significant sequelae. In more extensive lesions, incision or tangential ("shave") biopsy can be performed without impairing prognosis. In clinical presentations strongly suggestive of melanoma, immediate complete resection of the entire nail unit may be proposed.
Topics: Humans; Biopsy; Melanoma; Nail Diseases; Skin Neoplasms
PubMed: 38879227
DOI: 10.1016/j.hansur.2022.12.007 -
Skin Appendage Disorders Dec 2023Transverse melanonychia, characterized by grey to black pigmented bands traversing the nail plate, can occur as a side-effect of certain medications. While no documented...
INTRODUCTION
Transverse melanonychia, characterized by grey to black pigmented bands traversing the nail plate, can occur as a side-effect of certain medications. While no documented reports specifically associate dasatinib, a tyrosine kinase inhibitor used in the treatment of chronic myeloid leukaemia (CML) and acute lymphoblastic leukaemia, with nail changes, we present a case of transverse melanonychia possibly related to dasatinib therapy.
CASE REPORT
A 54-year-old male with CML, receiving dasatinib for 1.5 years, presented with transverse pigmented lines involving all fingernails and toenails. Clinical examination revealed discrete bands of transverse melanonychia in the nails. Onychoscopy of all finger- and toenails revealed multiple longitudinal grey lines within transverse grey bands of homogeneous chromonychia. Based on clinical presentation, onychoscopic features, and temporal association with dasatinib therapy, a provisional diagnosis of dasatinib-induced transverse melanonychia was made.
DISCUSSION
The exact mechanisms underlying melanonychia are not fully understood but may involve nail matrix or toxicity, stimulation of nail-matrix melanocytes, or drug deposition within the nail plate. This case highlights the possibility of dasatinib-induced transverse melanonychia and underscores the importance of monitoring and evaluating nail changes in patients undergoing dasatinib treatment.
PubMed: 38058546
DOI: 10.1159/000531928 -
Nanotechnology Jul 2023Understanding and controlling nanoscale interface phenomena, such as band bending and secondary phase formation, is crucial for electronic device optimization. In...
Understanding and controlling nanoscale interface phenomena, such as band bending and secondary phase formation, is crucial for electronic device optimization. In granular metal (GM) studies, where metal nanoparticles are embedded in an insulating matrix, the importance of interface phenomena is frequently neglected. We demonstrate that GMs can serve as an exemplar system for evaluating the role of secondary phases at interfaces through a combination of x-ray photoemission spectroscopy (XPS) and electrical transport studies. We investigated SiNas an alternative to more commonly used oxide-insulators, as SiN-based GMs may enable high temperature applications when paired with refractory metals. Comparing Co-SiNand Mo-SiNGMs, we found that, in the tunneling-dominated insulating regime, Mo-SiNhad reduced metal-silicide formation and orders-of-magnitude lower conductivity. XPS measurements indicate that metal-silicide and metal-nitride formation are mitigatable concerns in Mo-SiN. Given the metal-oxide formation seen in other GMs, SiNis an appealing alternative for metals that readily oxidize. Furthermore, SiNprovides a path to metal-nitride nanostructures, potentially useful for various applications in plasmonics, optics, and sensing.
PubMed: 37503937
DOI: 10.1088/1361-6528/ace4d2 -
Compendium of Continuing Education in... Feb 2024Besides meticulous application of proper bonding protocols and clinical technique, the clinical success of direct resin-based restorations is dependent on the selection...
Besides meticulous application of proper bonding protocols and clinical technique, the clinical success of direct resin-based restorations is dependent on the selection of the appropriate restorative material, curing light, and, whenever certain contours of the tooth need to be rebuilt, matrix band system. All of these aspects have seen significant developments and improvements over the years, all geared toward increased clinical success and longevity. Highlighting some of these key developments, this article provides an update on resin-based composites, curing lights, and matrix bands.
Topics: Humans; Dental Care; Dental Materials
PubMed: 38289628
DOI: No ID Found