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Graduate admissions committees in Europe have a challenging task of selecting students from an increasingly large pool of candidates with diverse application files. Graduate standardized testing can ease the comparison of application files. The purpose of this study was to examine whether the Graduate Record Examinations (GRE) is predictive of several dimensions of graduate success on English-taught research masters' programs in science, technology, engineering, and mathematics at a large European university. The data from 167 masters' students were collected. Hierarchical regression analyses were conducted. All GRE scales predicted Graduate Grade Point Average. Individual GRE scales predicted internship grade and supervisors' assessments of students' research performance and the content of their research report. None of the individual GRE scales predicted supervisors' assessments of students' practical skills, but the three GRE scales taken together improved the explanatory power of the model. The structure and style of students' research reports was not predicted by the GRE. All relationships were held after accounting for socioeconomic status. Overall, the GRE appeared as a reasonable predictor of graduate study success. Both the benefits and drawbacks of the implementation of the GRE in European masters' programs are discussed, as well as the legal limitations. [ABSTRACT FROM AUTHOR]

Copyright of Implantologie is the property of Quintessenz Verlags GmbH and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Introduction: The aim of this study was to measure the wear progress of three high performance polymers (HPP) materials as well as that of zirconia after artificial aging (simulated 2.5‐ and 5‐year of clinical service with thermo‐mechanical loading) and compare it with the well‐documented wear of lithium disilicate. Methods: Forty implants were used to restore a maxillary first premolar, where the abutment and the crown were manufactured as hybrid‐abutment‐crown and connected to the implant using a titanium insert. The implants were randomly divided, according to the restorative materials used, into five groups: 3Y‐TZP zirconia (Z), lithium disilicate (L), ceramic‐reinforced polyetheretherketon (P), nano‐hybrid composite resin (C) and polymer‐infiltrated ceramic‐network (E). All hybrid‐abutment‐crowns were produced using CAD/CAM technology. A design of a maxillary first premolar was created with an angle of 120° between the buccal and palatal cusps, which were designed as planes. The restorations were adhesively luted onto the titanium inserts, according to the manufacturers' recommendations for each material individually, by means of dual‐curing luting resin with the exception of group P, where the blocks were pre‐fitted (heat‐pressed) with an integrated titanium insert. The suprastructures were assembled onto the implants through titanium screws. The screw channels were sealed with Teflon tape and composite resin filling material that was polished to high‐gloss. All specimens underwent 1 200 000 thermo‐dynamic loading cycles with 49 N in a dual‐axis chewing simulator. Elastomeric impressions were made for all specimens after 600 000 and after 1 200 000 cycles. The corresponding impressions were imaged using a laser scanning microscope and then 3D‐analyzed using the software (Geomagic Wrap) to measure the volume loss of the wear area for all specimens. Statistical analysis was performed using Wilcoxon‐Test regarding the two different time measurements for each material. For the analysis of the material variable, Kruskal‐Wallis test was conducted followed by Mann–Whitney test. Results: Group Z showed statistically the lowest volume loss compared to the other test materials, both after 600 000 and 1 200 000 cycles of artificial aging, with a median value of 0.002 mm3 volume loss after 1 200 000 cycles. In contrast, group E showed the highest volume loss with median values of 0.18 and 0.3 mm3 after 600 000 and 1 200 000 cycles, respectively. Artificial aging had significantly negative effect on the volume loss for all test materials. In addition, the choice of material had statistical influence on the outcome. Conclusion: Monolithic zirconia ceramic demonstrated lower wear than that reported for enamel after simulated 5‐year of clinical service, whereas all other test materials showed higher volume loss after artificial aging. [ABSTRACT FROM AUTHOR]

Copyright of Quintessenz der Zahntechnik is the property of Quintessenz Verlags GmbH and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: This clinical study aimed to evaluate the outcomes of resin-bonded attachments (RBAs) for precision-retained removable dental prostheses (RDPs) after at least two years of clinical maintenance. Methods: Since December 1998, 205 RBAs (44 bonded to posterior teeth, 161 to anterior teeth) have been inserted in 123 patients (62 females and 61 males; mean age, 63.6 ± 9.6 years) who were recalled annually. The abutment teeth underwent a minimally invasive preparation limited to the enamel. RBAs were cast in a cobalt-chromium alloy with a minimum thickness of 0.5 mm and adhesively luted with a luting composite resin (Panavia 21 Ex or Panavia V5, Kuraray, Japan). We evaluated caries activity, plaque index, periodontal condition, and tooth vitality. The Kaplan-Meier survival curves were used to account for the reasons for failure. Results: The mean observation time of RBAs until the last recall visit was 84.5 ± 51.3 months (range, 3.6-270.6). During the observation period, 33 RBAs debonded in 27 patients (16.1%). The 10-year success rate according to the Kaplan-Meier analysis was 58.4%, which dropped to 46.2% after 15 years of observation if debonding was considered a failure. If rebonded RBAs were regarded as surviving, the 10- and 15-year survival rates would be 68.3% and 61%, respectively. Conclusions: The use of RBAs for precision-retained RDPs appears to be a promising alternative to conventionally retained RDPs. As reported in the literature, the survival rate and frequency of complications were comparable with those of conventional crown-retained attachments for RDPs. [ABSTRACT FROM AUTHOR]

Copyright of Implantologie is the property of Quintessenz Verlags GmbH and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ABSTRACT Objective Materials and Methods Results Conclusions Clinical Significance Data on the stability of soft tissues at pontic sites of resin‐bonded fixed dental protheses (RBFDP) are lacking. The purpose of this study was to evaluate soft tissue changes at pontic sites of cantilever zirconia ceramic RBFDPs with and without surgical pretreatment after different follow‐up periods in the esthetic zone.Impressions were taken after the insertion of the restorations and an intraoral scan was performed at follow‐up examinations. Dental casts were digitalized and superimposed with the follow‐up scan. Vertical and horizontal soft tissue changes were measured buccally and lingually at mucosal margin at the central cross‐section of each pontic, and for horizontal change at 1 and 2 mm below. One‐way ANOVA and Kruskal–Wallis test were performed to analyze the collected data.A total of 36 pontic sites with (n = 7) and without surgical pretreatment (n = 29) were evaluated at a follow‐up period of either > 4, > 6, or > 10 years (n = 12). The follow‐up period had no significant effect on the tissue change. Surgical pretreatment showed significantly higher tissue loss at 2 mm below the lingual mucosal margin than for sites without surgical pretreatment.Soft tissues at pontic sites remained stable with a tissue gain at the mucosal margin up to 10 years.Based on the findings of this study, cantilever resin‐bonded fixed dental protheses provide excellent functional and esthetic outcomes with preservation of soft tissues in the edentulous area of single missing incisors and a gingival sulcus‐like tissue growth at the mucosal margin forming an emergence profile at pontic sites similar to that of a natural tooth. [ABSTRACT FROM AUTHOR]

Aim: The objective of the present study was to investigate the effect of using different materials for the fabrication of implant abutments and crowns on the mechanical behavior of implant-supported single crowns after artificial aging. The materials were tested in different combinations to reveal whether using stiff or resilient materials as an abutment or a crown material might influence the fracture strength of the whole structure., Materials and Methods: A total of 40 implants (blueSKY) were restored with identical custom-made CAD/CAM abutments milled out of lithium disilicate or ceramic-reinforced polyetheretherketone (PEEK) and divided into five test groups (n = 8). Forty crowns made of three different materials (zirconia, lithium disilicate, and ceramic-reinforced PEEK) were used to restore the abutments. Specimens were subjected to mechanical loading up to 1,200,000 cycles in a chewing simulator (Kausimulator) with additional thermal cycling. The surviving specimens were subjected to quasi-static loading using a universal testing machine (Z010)., Results: The PEEK abutments with zirconia crowns showed the highest median failure load (3890.5 N) while the PEEK abutments with lithium disilicate crowns exhibited the lowest (1920 N). Fracture and deformation occurred in both the crowns and abutments., Conclusion: The failure load of the restorations was influenced by the material of the abutment and crown. Restoring PEEK abutments with zirconia crowns showed a high failure load and no screw loosening.

Purpose: The purpose of this study was to evaluate the temperature generated on the intaglio surface and efficiency when cutting different types of zirconia with different rotary instruments and rotational speeds., Methods: A conventional diamond rotary instrument (Brasseler, grit size 107 μm) and special diamond rotary instrument marketed to cut zirconia (4 ZR, Brasseler, grit size 126 μm) were tested on 3Y-TZP and 4Y-TZP zirconia with a rotation speed of 100,000 rpm and 200,000 rpm. Zirconia specimens were cut under water cooling (110 mL/min) in a custom-made holder attached to a universal testing machine. The temperature was recorded with infrared sensors pointing at the intaglio surface of the zirconia specimens., Results: A rotation speed of 200,000 rpm resulted in significantly shorter cutting times, but also in significantly higher temperatures at the intaglio surface of the zirconia specimens compared with a rotation speed of 100,000 rpm. Significantly shorter cutting times were observed for the conventional diamond rotary instrument than for the special rotary instrument marketed to cut zirconia. Using the special rotary instrument, significantly longer cutting times were recorded for 3Y-TZP than for 4Y-TZP., Conclusions: A conventional diamond rotary instrument was more efficient than a special rotary instrument. However, to avoid high temperatures when cutting zirconia clinically, a rotation speed of 100,000 rpm is recommended., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Ltd.)

Purpose: To investigate the influence of contamination and different cleaning methods on resin bonding to cobalt-chro- mium (CoCr) alloy disks., Materials and Methods: A total of 160 CoCr disks were divided into 3 groups. The first group (N = 64) was air abraded with alumina particles and contaminated with a silicone disclosing agent and saliva; the second group (N = 64) was air abraded but not contaminated; the third group (N = 32) was neither air abraded nor contaminated. The first two groups were di- vided into 4 subgroups (N = 16) according to the cleaning method: ultrasonic bath in 99% isopropanol, use of a cleaning suspension of zirconium oxide particles, use of a cleaning suspension based on 10-MDP salt, and treatment with atmo- spheric plasma. The third group was divided into 2 subgroups (N = 16): treatment with atmospheric plasma and no treat- ment. All CoCr specimens were bonded to plexiglas tubes filled with a bonding resin that contained phosphate monomer. Tensile bond strength (TBS) was examined by tensile testing after 3 and 150 days of water storage plus 37,500 thermal cy- cles (N = 8)., Results: After contamination, TBS was significantly reduced after 150 days of water storage. Groups without air abrasion showed initially low TBS and debonded spontaneously after 150 days of water storage., Conclusion: None of the cleaning methods was able to remove saliva and silicone disclosing agent on CoCr-alloy sur- faces. Surface activation by plasma treatment has no long-term effect on the bond strength.