The major drawback of cement-retained restorations is the extrusion of the excess cement into the peri-implant sulcus, with subsequent complications. Insufficient removal of the excess cement may initiate a local inflammatory process, which may lead to implant failure. This article presents a method of controlling cement flow on implant abutments, minimizing the excess cement around implant-retained restorations.
Cementation*

This study was performed to investigate the retrievability of the cementation type implant abutments. The cements used in this study were Cavitec, Tembond and Zine Phosphate Cement. The types of surface conditioning were no treatment, 50 microne sandblasting, 250 microne sandblasting, fine diamond finishing point and coarse diamond point. The retention of cast crown was measured with Instron University Testing Machine(Instron Engineering Co., U.S.A.) The results were as follows: 1. The Maximium retention was obtained by the group of Z.P.C. cementation and Coarse diamond point surface conditioning. 2. Z.P.C. shows maximum retention, and reduced in orders Tembond, Cavitec, No cement. 3. The value of retention of surface condition was highest in coarse diamond point, lowest in no tretment. 4. The similar results were obtained between fine diamond point and 50 microne sandblasting, coarse diamond point and 250 microne sandblasting. 5. The were no direct corelation between mechanical retetnion and cementation retention.
Cementation* ; Crowns ; Diamond

The aim of this study was to evaluate the marginal and internal gaps in CEREC3 CAD/CAM inlays of three different preparation designs. CEREC3 Inlays of three different preparation designs (n = 10) were fabricated according to Group I-conventional functional cusp capping/shoulder preparation, Group II-horizontal reduction of cusps and Group III-complete reduction of cusps/shoulder preparation. After cementation of inlays, the bucco-lingual cross section was performed through the center of tooth. Cross section images of 20 magnifications were obtained through the stereomicroscope. The gaps were measured using the Leica application suite software at each reference point. Statistical analysis was performed using one-way ANOVA and Tukey's test (alpha<0.05). The marginal gaps ranged from 80.0 to 97.8 microm for Group I, 42.0 to 194.8 microm for Group II, 51.0 to 80.2 microm for Group III. The internal gaps ranged from 90.5 to 304.1 microm for Group I, 80.0 to 274.8 microm for Group II, 79.7 to 296.7 microm for Group III. The gaps of each group were the smallest on the margin and the largest on the horizontal wall. For the CEREC3 CAD/CAM inlays, the simplified designs (groups II and III) did not demonstrate superior results compared to the traditional cusp capping design (group I).
Cementation ; Inlays ; Tooth

PURPOSE: To investigate the void parameters within the resin cements used for fiber post cementation by micro-CT (µCT) and regional push-out bonding strength. MATERIALS AND METHODS: Twenty-one, single and round shaped roots were enlarged with a low-speed drill following by endodontic treatment. The roots were divided into three groups (n=7) and fiber posts were cemented with Maxcem Elite, Multilink N and Superbond C&B resin cements. Specimens were scanned using µCT scanner at resolution of 13.7 µm. The number, area, and volume of voids between dentin and post were evaluated. A method of analysis based on the post segmentation was used, and coronal, middle and apical thirds considered separately. After the µCT analysis, roots were embedded in epoxy resin and sectioned into 2 mm thick slices (63 sections in total). Push-out testing was performed with universal testing device at 0.5 mm/min cross-head speed. Data were analyzed with Kruskal–Wallis and Mann–Whitney U tests (α=.05). RESULTS: Overall, significant differences between the resin cements and the post level were observed in the void number, area, and volume (P<.05). Super-Bond C&B showed the most void formation (44.86 ± 22.71). Multilink N showed the least void surface (3.51 ± 2.24 mm2) and volume (0.01 ± 0.01 mm3). Regional push-out bond strength of the cements was not different (P>.05). CONCLUSION: µCT proved to be a powerful non-destructive 3D analysis tool for visualizing the void parameters. Multilink N had the lowest void parameters. When efficiency of all cements was evaluated, direct relationship between the post region and push-out bonding strength was not observed.
Cementation* ; Dentin ; Resin Cements*

The purpose of this article is to present the clinical and laboratory procedures for single tooth restoration using "Combination Implant Crown". It is cemented on implant abutment and that abutment is screw-retained over implant body. This type of implant restorations has the advantages of cement-retained restoration while being antirotational and retrievable. And, more esthetic and functional result can be achieved by minimizing the size of access hole. The results were as follow : 1. Preparation of abutment below the cuffline should be avoided 2. Axial reduction of implant abutment should not be excessive because it may weaken the abutment 3. More esthetical and functional occlusal surface was achieved with a minimal access hole which is slightly larger than the diameter of hex driver to enable future total retrievability. 4. Combination Implant Crown has the advantages of both the cement-retained and screw-retained type implant restoration. 5. Cementation between implant crown and abutment reduces screw loosening through even force distribution.
Cementation ; Crowns* ; Tooth*

PURPOSE: The objective of this study was to determine the effect of the color of a background substructure on the overall color of a zirconia-based all-ceramic crown. MATERIALS AND METHODS: Twenty one posterior zirconia crowns were made for twenty subjects. Seven premolar crowns and six molar crowns were cemented onto abutments with metal post and core in the first and second group. In the third group, eight molar crowns were cemented onto abutments with a prefabricated post and composite core build-up. The color measurements of all-ceramic crowns were made before try-in, before and after cementation. A repeated measure ANOVA was used for a statistical analysis of a color change of all-ceramic crowns at alpha=.05. Twenty four zirconia specimens, with different core thicknesses (0.4-1 mm) were also prepared to obtain the contrast ratio of zirconia materials after veneering. RESULTS: L*, a*, and b* values of all-ceramic crowns cemented either on a metal cast post and core or on a prefabricated post did not show significant changes (P>.05). However, the slight color changes of zirconia crowns were detected and represented by DeltaE*ab values, ranging from 1.2 to 3.1. The contrast ratios of zirconia specimens were 0.92-0.95 after veneering. CONCLUSION: No significant differences were observed between the L*, a*, and b* values of zirconia crowns cemented either on a metal cast post and core or a prefabricated post and composite core. However, the color of a background substructure could affect the overall color of posterior zirconia restorations with clinically recommended core thickness according to DeltaE*ab values.
Bicuspid ; Cementation ; Crowns ; Molar ; Zirconium

The purpose of this study is to compared and analyze the shade changes(deltaE)about In-Ceram(R),IPS-Empress(R),OPC(R) by using of the spectrophotometer arising from initial status and before and after cementation of the resin cement mounted on the metal core. We used a couple of statistics such as 'One-Way ANOVA'and Multiple Range Test. We could be able to verify significantly what is being discussed here up to 95%. The results drawn from our research are as follows: 1. At the time of our experiments regarding the initial shapes of all-ceramic and mounting status of all-ceramic on the metal crown(deltaE1), and a comparison of mounting of all ceramic on the metal crown with all-ceramic cemented on the metal core(deltaE2), at the time of shade change of initial shapes and after we cemented on the metal core. (1) no significant difference among all-ceramics was found. (2) no particular difference was found regarding the In-Ceram(R) (3) a significant difference between the deltaE1 and deltaE2 regarding the IPSS-Empress(R) was found (P<0.05). (4) a significant difference between the deltaE1 and deltaE2 regarding the OPC? was found (P<0.05). 2. When we compared the shade changes (deltaE) resulted from before and after the cementation on each of the parts involved of some all-ceramic . we could be able to find shape change increase from incisal third, middle third, and cervical third in that order in In-Cream(R)(spinell), IPS Empress(R) and OPC(R) all. In addition , we could be able to find a siginificant difference between cervical third and incisal third, middle third. (P<0.05) From what we have just seen, we might conclude that there is a significant shade change difference before and after the cementation with respect to IPS-Empress(R)and OPC(R). In addition, we could also be able to find more shade change difference at the cervical third rather than incisal third and middle third depending on the parts involved.
Cementation ; Ceramics* ; Crowns* ; Resin Cements

Recently as the esthetic concerns about dental prosthesis have been increased, the nonmetallic post and core systems have been introduced clinically to improve the color and the low optical transmittance of conventional casting metal post and core systems. The purpose of this study was to compare and analyze the optical transmittance and the shade changes of all-ceramic crowns with two nonmetallic post and core systems. The experimental groups were classified as follows: Total 27 specimens(9 samples in each group) were evaluated. Group I: Natural teeth as a control group. Group II: CosmoPost and Empress(R) core (Ivoclar-Vivadent, Liechtenstein). Group III: LIGHT-POST(TM) and LIGHT-CORE(TM)(Bisco, U.S.A.). In all groups, all-ceramic crowns were fabricated with the same shade of IPS Empress(R)II(Ivoclar-Vivadent, Liechtenstein) after abutment preparation, and then two kinds of spectrophotometers, UV 3101 PC(Shimadzu,Japan) and CM 503i(Minolta Co., Ltd., Japan), were used to measure the optical transmittance and the color value. The following results were obtained: 1. The optical transmittance of each group without all-ceramic crowns, was siginificantly decreased in order of Group III, I and II(p<0.05). 2. The optical transmittance of each group with all-ceramic crowns cemented, were siginificantly decreased in order of Group I, II and III(p<0.05). 3. In comparison with the shade of all-ceramic crowns, there were no significant differences between groups regardless of the cementation. 4. In comparison with the shade changes in each group after the cementation of all-ceramic crowns, there were no significant differences between groups. From the above results, it is thought that the selection among materials used in this study doesn't influence greatly the esthetic restoration, because the differences of optical transmittance were so small that those were clinically insignificant.
Cementation ; Crowns* ; Dental Prosthesis ; Tooth

Removal of excess cement is important to prevent biological complication in cementation of implant restoration with subgingival margin. It can be difficult to completely remove excess cement. Several techniques have been introduced to minimize excess cement using abutment replica. In this case report, a simple method for making abutment replica with hot melt adhesive material in dental office was described. This technique is simple and effective because it can be used for pre-fabricated or custom abutment without additional laboratory procedure. In addition, it can minimize excess cement after cementation of implant restoration.
Adhesives* ; Cementation ; Dental Offices ; Methods

STATEMENT OF PROBLEM: Targis/Vectris restorations provide excellent esthetics. Marginal accuracy is significantly influenced by the preparation design. There were no studies to examine the effect of preparation design on the marginal discrepancy and fracture strength of Targis/Vectris crowns. PURPOSE: This study evaluated the marginal accuracy before and after cementation, and the fracture strength of FRC/Ceromer(Targis/Vectris) crowns according to different preparation design. MATERIAL AND METHOD: Three metal dies with different convergence angles(6degrees, 10degrees, 15degrees) were prepared. Total 30 (10 for each angle) Targis/Vectris crowns were made. The restorations were evaluated for adaptation of the margin before and after cementation, then were compressively loaded to failure. Fracture surfaces of the crowns were examined using a SEM. Results. The mean marginal gap was 49micrometer for 6degrees, 55micrometer for 10degreesand 70micrometer for 15degreesand in clinically acceptable level. The mean marginal gap increased significantly after cementation. The increasing amount during cementation was the largest in the 6degrees group. The crowns on 6o convergence angle had a significantly higher fracture strength than the crowns on 15degrees angle. Mean fracture strength of total crowns regardless of convergence angle was 1390 N, which was higher than all-ceramic crowns. SEM observation showed two-mode fracture pattern. CONCLUSION: From the results of this study, all of the FRC/Ceromer crowns had clinically acceptable marginal accuracy and could withstand the bite force. Moreover, less convergent angle than all-ceramic crown might be recommended for preparation procedure.
Bite Force ; Cementation ; Crowns* ; Esthetics