Objective: This in vitro study aimed to evaluate marginal and internal fit of single crowns produced from high-frequency ultrasound based digital impressions of teeth prepared with finish lines covered by porcine gingiva, in comparison with those obtained by optical scanners with uncovered finish lines.
Methods: Ten human teeth were prepared and forty zirconia crowns were fabricated from STL-datasets obtained from four dental scanners (n=10): extraoral CS2 (Straumann), intraoral Lava COS (3M), intraoral Trios (3Shape) and extraoral ultrasound scanner. The accuracy of the crowns was compared evaluating marginal and internal fit by means of the replica technique with measurements in four areas; P1: occlusal surface; P2: transition between occlusal and axial surfaces; P3: middle of axial wall; and P4: marginal gap. Restoration margins were classified according to their mismatch as regular, underextended or overextended. Kruskal-Wallis one-way ANOVA and Mann-Whitney U test were used to evaluate the differences between groups at p<0.05.
Results: The median value of marginal gap (P4) for Ultrasound (113.87μm) differed statistically from that of CS2 (39.74μm), Lava COS (41.98μm) and Trios (42.07μm). There were no statistical differences between ultrasound and Lava COS for internal misfit (P1-P3), however there were statistical differences when compared with the other two scanners (Trios and CS2) at P1 and P2.
Significance: The ultrasound scanner was able to make digital impressions of prepared teeth through porcine gingiva (P4), however with less accuracy of fit than that of conventional optical scanners without coverage of the finish lines. Where no gingiva was available (P1-P3), the ultrasound accuracy of fit was similar to that of at least one optical scanner (Lava COS).
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http://dx.doi.org/10.1016/j.dental.2018.08.301 | DOI Listing |
PeerJ
December 2024
The Thomas H. Gosnell School of Life Sciences, Biotechnology and Molecular Bioscience Program, College of Science, Rochester Institute of Technology, Rochester, New York, United States.
Background: A grapevine crown gall tumor strain, sp. strain Rr2-17 was previously reported to accumulate copious amounts of diverse quorum sensing signals during growth. Genome sequencing identified a single luxI homolog in strain Rr2-17, suggesting that it may encode for a AHL synthase with broad substrate range, pending functional validation.
View Article and Find Full Text PDFDent Res J (Isfahan)
November 2024
Student Research Committee, Dental School, Urmia University of Medical Sciences, Urmia, Iran.
Background: This study compared the antibacterial effects of 940 nm diode laser and sodium hypochlorite and chlorhexidine irrigations on in human permanent single-rooted teeth.
Materials And Methods: In this study, 65 extracted human single-rooted teeth were prepared using the crown-down method using rotary files. The root canals were irrigated with 5.
BMC Pregnancy Childbirth
December 2024
Academic Women's Health Unit, Bristol Medical School, University of Bristol, 5 Tyndall Avenue, Bristol, BS8 1UD, UK.
Background: Expectations of birth, and whether they are met, influence postnatal psychological wellbeing. Intrapartum interventions, for example induction of labour, are increasing due to a changing pregnant population and evolving evidence, which may contribute to a mismatch between expectations and birth experience. NICE recommends antenatal education (ANE) to prepare women for labour and birth, but there is no mandated UK National Health Service (NHS) ANE curriculum.
View Article and Find Full Text PDFJ Fungi (Basel)
December 2024
Laboratory of Helminthology, National Centre for Disciplinary Research in Animal Health and Innocuity (CENID-SAI), National Institute for Research in Forestry, Agriculture and Livestock (INIFAP-AGRICULTURA), Jiutepec 62550, Mexico.
During the isolation, identification, and assessment of nematode-trapping fungi (NTF) against nematodes, we discovered an unusual fungus in decaying wood from Morelos State, Mexico. This isolate exhibited some characteristics similar to those of the genus; however, we found that it did not match any previously reported species within this genus after conducting morphological and phylogenetic analyses using the ITS, TEF, and RPB2 regions. This new species displays conidiophores with two or three stems emerging from the same initial site and conidiophores with only a single stem and aerial thickened hyphae from which single conidiophores emerge, forming 3D adhesive nets.
View Article and Find Full Text PDFCrown ether is widely used in water purification because of its ring structure and good selective adsorption of specific heavy metals. However, its high cost and difficulty in recycling limit the purification of heavy metals in water. The anisotropic [2,4]-dibenzo-18-crown-6-modified bamboo pulp aerogel (DB18C6/PA) is successfully synthesized by microwave irradiation and directional freezing technology.
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