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-60-initial LiSiPress0660 Wear Resistance of PressableLithium Silicate Glass CeramicsPoster Presentation11:00 AM–12:15 PM Mar 23, 2017CC, First FloorAuthors:Authors:Tatsuya Fujimoto (Presenter)GC CorporationDaizaburoMori, GC CorporationGo Mashio, GC CorporationMasatoshi Yoshinaga, GC CorporationHayatoYokohara, GC CorporationTomohiro Hoshino, GC CorporationTakahiro Miyake, GC CorporationTakahiro Miyake, GC CorporationTOSHIHIKO AZUMA, GC CorporationTakuya Sato, GC CorporationTomohiro Kumagai, GC CorporationAbstract: Objectives: Pressablelithium silicate glass ceramics are known as useful materials clinically from the viewpoint of aesthetics and biological compatibility, and used widely now. Wear the viewpoint of aesthetics and biological compatibility, and used widely now. Wear charactaristicsis closely related to good longevity of restorations. The purpose of this study was to evaluate the wear resistance of lithium silicate based pressablematerials.Methods: The wear resistance of Initial LiSiPress (LS, GC Corp.) and IPS e.max Press (EM, IvoclarVivadent) were evaluated by two-body wear test. Specimens (Φ2.1mm) were prepared following the manufacturer’s instructions, and polished. These specimens were attached to the testing machine and specimens were contacted with Hydroxyapatite(HAp) as antagonists in water. The testing machine gave repeatedly load with sliding movement to the contact surface of the specimen at 400,000 cycles. The depth of wear was calculated from the height measurement the specimen at 400,000 cycles. The depth of wear was calculated from the height measurement of specimen before and after wear test, and one-way ANOVA was used to assess the significant difference. Wear surface was observed with laser microscope. And crystal structure of each material was observed with SEM.Results: In the evaluation of wear resistance, LS showed lower depth of wear than EM (p<0.001). And damage to antagonists was also lower in LS group. SEM observation revealed that lithium disilicatecrystal of LS were smaller than that of EM. That is, because of micronized crystal, large defects hardly happened and the depth of wear showed low value.Conclusions: Initial LiSiPress has not only superior wear resistance by HDM (High Density Conclusions: Initial LiSiPress has not only superior wear resistance by HDM (High Density Micronize) technology but also less abrasive against antagonist.Table(s):Material, codeDepth of wear / µm (n=4)Initial LiSi Press, LS11.2 ± 3.9IPS e.max Press, EM27.7 ± 4.3HAp (vs LS)19.6 ± 2.5Disclosure Statement:The submitter must disclose the names of the organizations with which any author have a relationship, the nature of the relationship, and the clinical or research area involved. The following is submitted: NONEI have read the IADR policy on licensing.Signed by TATSUYA FUJIMOTOHAp (vs LS)19.6 ± 2.5HAp (vs EM)27.7 ± 3.1Reprinted with permission from the Journal of Dental Research, J Dent Res 96 (Spec Iss A):-60-abstract number 0660, https://iadr2017.zerista.com/event/member/330645, 2017