Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Intra-oral repair of fractured porcelain is a challenging clinical necessity, because time, economics, as well as possible trauma to teeth, often contra-indicate replacement of the original restoration. The purpose of this study was to evaluate the bond strength of seven different porcelain repair systems used in combination with Cerec Vitablocs Mark II porcelain. The systems were Scotchbond Multi-Purpose (SMP), All-Bond 2 (AB), Optibond (OB), C&B Metabond (CB), Imperva Bond (IB), Silistor (S) and Mirage Bond (MB). When Mirage Bond was used, the porcelain was either etched with 9.6 percent hydrofluoric acid for 2 min (10 specimens = MB1) or with 4 percent APF gel for 2 min (10 specimens = MB2). The shear bond strengths (SBS) of all the products were determined using an Instron. The effects of the pretreatments on the porcelain with different systems were also examined in a SEM. Data were statistically analysed (Wilcoxon Sum of Rank Test). The mean SBS (MPa) of the products were: SMP = 22.6 +/- 6.5; AB = 17.1 +/- 4.1; OB = 17.1 +/- 2.3; CB = 25.8 +/- 4.2; IB = 18.3 +/- 5.2; S = 16.4 +/- 3.7; MB1 = 13.1 +/- 3.9 and MB2 = 6 +/- 2.1. CB and SMP were significantly stronger (p < 0.05) than all other products, with MB2 statistically weaker (p < 0.01) than the other groups. Most specimens showed cohesive fractures in the porcelain, except when MB was used with 4 percent APF gel, where all samples fractured at the adhesive interface. It can be concluded that all seven systems can be used to repair Cerec Porcelain, except possibly MB when used in conjunction with 4 percent APF etchant.
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PMID:Repair of Cerec porcelain with seven different systems. 946 29

Various authors have investigated the frequency of second canals (MB2) in the mesiobuccal roots of maxillary molars, predominantly first molars. Further, it has been reported that the percentage of MB2 canals that are treated during routine endodontic therapy is much lower than the number of second canals identified in vitro. It was the purpose of this study to investigate whether the use of an operating microscope may improve the diagnosis of MB2 canals in mesiobuccal roots of maxillary molars. The canal orifices of 100 maxillary first and second molars (50 of each) were initially inspected by Examiner 1 using individually-adapted x2 magnifying loupes. Subsequently, all teeth were examined by a second investigator using an operating microscope (OPM) with x8 magnification. Finally, the mesiobuccal roots of all teeth were separated. Then, the sections were analysed histologically and by SEM. The histological investigation revealed a total number of 63 MB2 canals, 39 in first, and 24 in second molars. Only 26 (41.3%) of those canals were identified using magnifying loupes, whereas 59 (93.7%) were found by means of an operating microscope.
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PMID:Identification of second canals in the mesiobuccal root of maxillary first and second molars using magnifying loupes or an operating microscope. 1236 Jun 70