A Comparative Three- and Bi-dimensional Research of the Marginal Fit of Pressed Lithium Disilicate Inlays

2017 ◽  
Vol 68 (6) ◽  
pp. 1316-1319
Author(s):  
Sorana Baciu ◽  
Cristian Berece ◽  
Adrian Florea ◽  
Alexandru Victor Burde ◽  
Meda Lavinia Negrutiu ◽  
...  
Keyword(s):  
Lithium Disilicate ◽  
Ceramic Materials ◽  
Micro Ct ◽  
Marginal Fit ◽  
Common Solution ◽  
Different Types ◽  
Marginal Discrepancy ◽  
2D And 3D ◽  
Posterior Area

The replacement of classical fillings, especially in the posterior area with different types of inlays has become a common solution used in order to improve all parameters which insure a long lasting treatment. Vrious ceramic materials and systems are available, but so far an ideal ceramic material suited for all clinical situations, has not been found. The range of ceramic materials as: lithium disilicate, aluminum oxide, zirconium oxide and hybrid ceramics enhance the possibilities of using ceramic inalys in various clinical situations. Marginal adaptation is one of the most important conditions for long-term success for any type of material. The marginal discrepancy of fixed restorations is one of the main factors which lead to failure of the prosthetic treatment.The purpose of the present study is to compare a 2D and 3D method for evaluating the marginal fit for pressed lithium dislicate inlays (Emax). The two used methods were: SEM- electronic microscopy and micro CT.

scholarly journals Effects of Printing Parameters on the Fit of Implant-Supported 3D Printing Resin Prosthetics

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2533 ◽  
Author(s):  
Gang-Seok Park ◽  
Seong-Kyun Kim ◽  
Seong-Joo Heo ◽  
Jai-Young Koak ◽  
Deog-Gyu Seo
Keyword(s):  
3D Printing ◽  
Layer Thickness ◽  
Micro Ct ◽  
Marginal Fit ◽  
Dental Model ◽  
Marginal Discrepancy ◽  
3D Printed ◽  
Ct Data ◽  
Internal Gap ◽  
Printing Parameters

The purpose of the study was to investigate the influence of 3D printing parameters on fit and internal gap of 3D printed resin dental prosthesis. The dental model was simulated and fabricated for three-unit prostheses with two implants. One hundred prostheses were 3D printed with two-layer thicknesses for five build orientations using a resin (NextDent C&B; 3D systems, Soesterberg, The Netherlands) and ten prostheses were manufactured with a milling resin as control. The prostheses were seated and scanned with micro-CT (computerized tomography). Internal gap volume (IGV) was calculated from 3D reconstructed micro-CT data. IGV, marginal fit, and lengths of internal gaps were measured, and the values were analyzed statistically. For the 3D printed prostheses, IGV was smaller at 45°, 60°, and 90° compared to other build orientations. The marginal fit evaluated by absolute marginal discrepancy was smaller than other build orientations at 45° and 60°. IGV was smaller at 50 µm layer thickness than at 100 µm layer thickness, but the marginal fit was smaller at 100 µm layer thickness than at 50 µm layer thickness. The 3D printed prosthesis had smaller internal gap than the milled prosthesis. The marginal fit of the 3D printed resin prosthesis was clinically acceptable, and build orientation of 45° and 60° would be recommended when considering fit and internal gap.

Three-dimensional Marginal Evaluation of Two Pressed Materials Using Micro-CT Technology

2017 ◽  
Vol 68 (3) ◽  
pp. 615-618
Author(s):  
Sorana Baciu ◽  
Cristian Berece ◽  
Adrian Florea ◽  
Alexandru Victor Burde ◽  
Anda Munteanu ◽  
...  
Keyword(s):  
Statistical Difference ◽  
Three Dimensional ◽  
Lithium Disilicate ◽  
Marginal Adaptation ◽  
Micro Ct ◽  
Thermoplastic Resin ◽  
Marginal Gap ◽  
Marginal Fit ◽  
Significant Statistical Difference ◽  
Ct Technology

The main goal of the present study is to compare the marginal fit of two different kind of pressed materials: a partially crystalline thermoplastic resin reinforced with ceramic particles (BioHPP) and lithium disilicate (EMax), through the use of the microCT technique. After extraction of four caries-free mandibular first molars, first class inlay cavities were prepared. For each tooth two inlays were manufactured- one by using BioHPP thermoplastic resin (n=4) and one by using Emax Press lithium disilicate (n=4). The marginal gap was analyzed circumferentially at the occlusal margin using a Bruker micro CT, by measuring the distance at the occlusal limit of the cavities, between the restoration and the tooth in several points for every surface of each tooth before cementing. Data were analyzed statistically using the Mann-Whitney U test and the Pearson�s correlation coefficient (a=0.05). A significant statistical difference was found between the marginal gap size obtained for BioHPP and Emax inlays (p[0.001). For the Emax inlays the marginal gap had an average of 72mm, while for BioHPP the average was 94 �m. Both types of used materials offer a good marginal adaptation. By summing up the gathered data we can conclude that the pressed ceramics shows a better marginal fit than the pressed resin, probably because of the different processing methods: sintering versus polymerizing with different shrinkage values.

scholarly journals In vitro Evaluation of the Marginal Fit and Internal Adaptation of Zirconia and Lithium Disilicate Single Crowns: Micro-CT Comparison Between Different Manufacturing Procedures

2018 ◽  
Vol 12 (1) ◽  
pp. 160-172 ◽  
Author(s):  
Francesco Riccitiello ◽  
Massimo Amato ◽  
Renato Leone ◽  
Gianrico Spagnuolo ◽  
Roberto Sorrentino
Keyword(s):  
Clinical Success ◽  
Lithium Disilicate ◽  
Resin Cement ◽  
Micro Ct ◽  
Marginal Fit ◽  
Restorative Materials ◽  
Cad Cam ◽  
Internal Adaptation ◽  
Single Crowns

Background:Prosthetic precision can be affected by several variables, such as restorative materials, manufacturing procedures, framework design, cementation techniques and aging. Marginal adaptation is critical for long-term longevity and clinical success of dental restorations. Marginal misfit may lead to cement exposure to oral fluids, resulting in microleakage and cement dissolution. As a consequence, marginal discrepancies enhance percolation of bacteria, food and oral debris, potentially causing secondary caries, endodontic inflammation and periodontal disease.Objective:The aim of the presentin vitrostudy was to evaluate the marginal and internal adaptation of zirconia and lithium disilicate single crowns, produced with different manufacturing procedures.Methods:Forty-five intact human maxillary premolars were prepared for single crowns by means of standardized preparations. All-ceramic crowns were fabricated with either CAD-CAM or heat-pressing procedures (CAD-CAM zirconia, CAD-CAM lithium disilicate, heat-pressed lithium disilicate) and cemented onto the teeth with a universal resin cement. Non-destructive micro-CT scanning was used to achieve the marginal and internal gaps in the coronal and sagittal planes; then, precision of fit measurements were calculated in a dedicated software and the results were statistically analyzed.Results:The heat-pressed lithium disilicate crowns were significantly less accurate at the prosthetic margins (p<0.05) while they performed better at the occlusal surface (p<0.05). No significant differences were noticed between CAD-CAM zirconia and lithium disilicate crowns (p>0.05); nevertheless CAD-CAM zirconia copings presented the best marginal fit among the experimental groups. As to the thickness of the cement layer, reduced amounts of luting agent were noticed at the finishing line, whereas a thicker layer was reported at the occlusal level.Conclusion:Within the limitations of the presentin vitroinvestigation, the following conclusions can be drawn: the recorded marginal gaps were within the clinical acceptability irrespective of both the restorative material and the manufacturing procedures; the CAD-CAM processing techniques for both zirconia and lithium disilicate produced more consistent marginal gaps than the heat-pressing procedures; the tested universal resin cement can be safely used with both restorative materials.

Marginal Fit Evaluation Trough Micro-CT Technology of Pressed vs Milled Ceramic Inlays

2017 ◽  
Vol 68 (8) ◽  
pp. 1919-1922
Author(s):  
Marius Manole ◽  
Cristian Berece ◽  
Adrian Florea ◽  
Alexandru Victor Burde ◽  
Cosmin Sinescu ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Statistical Significance ◽  
Lithium Disilicate ◽  
Micro Ct ◽  
Marginal Gap ◽  
Marginal Fit ◽  
Ceramic Inlays ◽  
Multiple Comparison Test ◽  
Ct Technology ◽  
One Way Anova

The goal of the present study is to compare the marginal fit using microCT of ceramic inlays obtained using two different technologies: pressing technique (lithium disilicate) and milling technique (milled leucite glass-ceramic). After extraction of four caries-free mandibular first molars, first class inlay cavities were prepared. For each tooth two inlays were manufactured- one by using pressed lithium disilicate (Emax) (n=4) and one by using milled leucite glass-ceramic (n=4). The marginal gap was analyzed circumferentially at the occlusal margin using a table-top Bruker micro CT, by measuring the distance at the occlusal limit of the cavities, between the restoration and the tooth in several points for every surface of each tooth before cementing. Data were analyzed statistically using One �way ANOVA with Tukey�s Multiple Comparison Test performed using 5.00 for Windows (GraphPad Prism 5.00 Software, San Diego, California USA). When the marginal gaps of the inlays made out of different materials on the same tooth were compared, only one result had no statistical significance. The program expressed also results by comparing the gaps of pressed vs milled restorations on different teeth. 11 out of 16 results had statistical significance. Although statistical significance between the two studied materials, we can conclude that both used materials offer a good marginal adaptation within the acceptable limits. By summing up the gathered data we can conclude that the milled ceramic shows a better marginal fit than the pressed ceramic.

The Acute Effect of Alcohol on Various Memory Processes

2010 ◽  
Vol 24 (4) ◽  
pp. 249-252 ◽  
Author(s):  
Márk Molnár ◽  
Roland Boha ◽  
Balázs Czigler ◽  
Zsófia Anna Gaál
Keyword(s):  
Low Dose ◽  
Short Term Memory ◽  
Acute Effect ◽  
Long Term Memory ◽  
Term Memory ◽  
Memory Processes ◽  
Different Types ◽  
The Brain ◽  
Legal Consequences

This review surveys relevant and recent data of the pertinent literature regarding the acute effect of alcohol on various kinds of memory processes with special emphasis on working memory. The characteristics of different types of long-term memory (LTM) and short-term memory (STM) processes are summarized with an attempt to relate these to various structures in the brain. LTM is typically impaired by chronic alcohol intake but according to some data a single dose of ethanol may have long lasting effects if administered at a critically important age. The most commonly seen deleterious acute effect of alcohol to STM appears following large doses of ethanol in conditions of “binge drinking” causing the “blackout” phenomenon. However, with the application of various techniques and well-structured behavioral paradigms it is possible to detect, albeit occasionally, subtle changes of cognitive processes even as a result of a low dose of alcohol. These data may be important for the consideration of legal consequences of low-dose ethanol intake in conditions such as driving, etc.

Effect of sleep on memory for binding different types of visual information

2020 ◽  
Author(s):  
John J Shaw ◽  
Zhisen Urgolites ◽  
Padraic Monaghan
Keyword(s):  
Visual Information ◽  
Storage Capacity ◽  
Declarative Memory ◽  
Recognition Task ◽  
Forced Choice ◽  
Long Term Memory ◽  
Term Memory ◽  
Different Types ◽  
Types Of Information

Visual long-term memory has a large and detailed storage capacity for individual scenes, objects, and actions. However, memory for combinations of actions and scenes is poorer, suggesting difficulty in binding this information together. Sleep can enhance declarative memory of information, but whether sleep can also boost memory for binding information and whether the effect is general across different types of information is not yet known. Experiments 1 to 3 tested effects of sleep on binding actions and scenes, and Experiments 4 and 5 tested binding of objects and scenes. Participants viewed composites and were tested 12-hours later after a delay consisting of sleep (9pm-9am) or wake (9am-9pm), on an alternative forced choice recognition task. For action-scene composites, memory was relatively poor with no significant effect of sleep. For object-scene composites sleep did improve memory. Sleep can promote binding in memory, depending on the type of information to be combined.

scholarly journals Influence of Silane Pretreatment and Warm Air-Drying on Long-Term Composite Adaptation to Lithium Disilicate Ceramic

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 86
Author(s):  
Pa Pa Kay Khine ◽  
Antonin Tichy ◽  
Ahmed Abdou ◽  
Keiichi Hosaka ◽  
Yasunori Sumi ◽  
...  
Keyword(s):  
Resin Composite ◽  
Lithium Disilicate ◽  
Drying Methods ◽  
Gap Formation ◽  
Universal Adhesive ◽  
Air Drying ◽  
Swept Source ◽  
Long Term Stability ◽  
Interfacial Gap

Background: Repair bonding to lithium disilicate ceramic (LDS) remains an issue. This study examined whether the adaptation of a resin composite to LDS can be improved by a silane pretreatment and warm air-drying. Methods: LDS blocks (IPS e.max CAD) with prefabricated tapered cavities were bonded using a silane-containing universal adhesive (Clearfil Universal Bond Quick ER; UBQ) or the bonding agent of a two-step self-etch adhesive (Clearfil SE Bond 2), with and without a silane pretreatment (Clearfil Ceramic Primer; CP). CP and the adhesives were air-dried with normal air (23 ± 1 °C) or warm air (60 ± 5 °C), light-cured, and the cavities were filled with a flowable composite. Interfacial gap formation was evaluated using swept-source optical coherence tomography immediately after filling, after 24 h, 5000 and 10,000 thermal cycles, and an additional 1 year of water storage. Results: Without the silane pretreatment, all specimens soon detached from the cavities. Warm air-drying significantly decreased gap formation compared to normal air-dried groups (p < 0.001) and improved long-term stability (p < 0.001). The lowest gap formation was observed with UBQ when the silane pretreatment was combined with warm air-drying. Conclusions: Composite adaptation to LDS was insufficient without silanization, but it was stable in the long term if the silane pretreatment and warm air-drying were combined.

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