scholarly journals Evaluation of Internal Fit and Marginal Adaptation of Provisional Crowns Fabricated with Three Different Techniques

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 740
Author(s):  
Jie Wu ◽  
Hongjun Xie ◽  
Alireza Sadr ◽  
Kwok-Hung Chung

Different techniques have been used to construct provisional crowns to protect prepared teeth. The purpose of this in vitro study was to assess the internal fit and marginal discrepancy of provisional crowns made by different methods. A total of 48 provisional crowns were constructed and divided into three groups (n = 16) according to the fabrication methods: fabricated manually-group MAN; computer-aided design/computer aided manufacturing technology-group CAM; and 3-dimensional (3D)-printed technology-group 3DP. The same standard tessellation language (STL) file was used for both CAD/CAM and 3D-printed group. The silicone-checked method was used to measure the internal gap distance. The marginal discrepancy was measured by using the polyvinyl siloxane (PVS) replica method and swept-source optical coherence tomography (OCT) scanning technique. Data were analyzed with one-way analysis of variance (ANOVA) nonparametric Kruskal-Wallis and Tukey tests at α = 0.05. At the central pit and axial walls, the gap distance mean values of group CAM were higher than those from group MAN and 3DP. The group 3DP was statistically significantly higher in gap distance at the location of occlusion than group MAN and group CAM (p < 0.05). The total gap distances assessed by silicone-checked method revealed there were no statistically significant differences between the tested groups (p > 0.05). The total mean values of absolute and horizontal marginal discrepancy of the group 3DP obtained by using the PVS-replica method and OCT scanning technique were significantly higher than the group MAN and CAM (p < 0.05). Regression correlation results of marginal discrepancy indicated a positive correlation (r = 0.902) between PVS-replica method and OCT scanning technique. The manually fabricated provisional crowns presented better internal fit and a smaller marginal discrepancy. Between different assessment techniques for marginal adaptation, PVS-replica method and OCT scanning technique have a positive correlation.

Author(s):  
Maximiliane Amelie Schlenz ◽  
Jonas Vogler ◽  
Alexander Schmidt ◽  
Peter Rehmann ◽  
Bernd Wöstmann

To measure the internal fit of the computer-aided designed/computer-aided manufactured (CAD/CAM) crowns, a new scanner-based chairside approach was investigated in patients, and the results were compared to the established silicone replica technique and a digital laboratory replica method. Thirty full-coverage crown preparations were included. Based on a digital impression with an intraoral scanner (IOS, Trios 3), three CAD/CAM measurement copings (‘COM’, resin composite; ‘ZIR’, zirconium dioxide; ‘NPA’, non-precious alloy) were fabricated for each tooth preparation. The internal fit of the measurement copings was analyzed with three different evaluation methods: IOS-based digital approach (D-IOS), digital replica method with laboratory software (D-GOM), and conventional silicone replica technique (CV-SR). The congruence between the determined target parameter of the 80-µm cement space and the actual measured internal gap was investigated. Statistical analysis was performed by ANOVA (p-value < 0.05). No significant difference was determined between the three evaluation methods. However, significant differences were observed for the three coping materials (p-value < 0.05), the single measurement position (marginal, axial, and occlusal fit) (p-value < 0.05), and the interaction between the coping material and the measurement position (p-value < 0.05). COM revealed the smallest internal gap, followed by ZIR and NPA. Regardless of the coping material, the occlusal gap was higher than the axial and marginal gaps. Furthermore, only the internal gaps of the marginal area almost matched the target parameter of 80-µm for the cement space. D-IOS is effective for measuring internal fit of single crowns in different clinical settings.


2019 ◽  
Vol 24 (6) ◽  
pp. 1929-1938 ◽  
Author(s):  
Rinet Dauti ◽  
Bledar Lilaj ◽  
Patrick Heimel ◽  
Andreas Moritz ◽  
Andreas Schedle ◽  
...  

Abstract Objectives The study evaluates the influence of two spacer settings and three resin luting materials on the marginal and internal fit of polymer-infiltrated ceramic network (PICN) material crowns manufactured using a complete digital workflow. Methods Optical impressions of fifty identical dies were performed using the 3M scanner (software version 5.0.2). Twenty crowns were designed using Ceramill Mind (version 3.4.10.1163), from which ten with spacer setting of 50 μm (G1) and ten with 80 μm (G2). Thirty crowns (spacer setting of 50 μm) were divided into three groups corresponding to the resin materials used as follows: RelyX Unicem (RX), Variolink Esthetic (VLE), and Nexus 3 (NX3). All crowns were milled from Vita Enamic blocks. After micro-CT scanning, absolute marginal discrepancy (AMD), internal gap (IG), total cement space volume (TCV), and marginal porosities (VP) were measured. Results Significant difference was detected on the VP between the RX and NX3 group (p = 0.033). The mean values of all parameters were the following: AMD (μm): G1 182.6, G2 253.7, RX 210.8, VLE 195.5, NX3 186.6; IG (μm): G1 215.6, G2 173.1, RX 171.1, VLE 198.6, NX3 203; TCV (mm3): G1 22.9, G2 20.49, RX 17.57, VLE 17.49, NX3 20.59; VP (mm3): G1 0.26, G2 0.34, RX 0.32, VLE 0.46, NX3 0.54. Conclusions Fit of PICN material crowns was not significantly influenced by increasing the spacer settings and cementation with different resin materials. Additionally, RelyX Unicem showed significantly less porosities as compared with Nexus3. Clinical relevance Both 50 μm and 80 μm virtual spacer settings can be suggested for the manufacture of PICN crowns when Ceramill Mind (version 3.4.10.1163) is used. Furthermore, a self-adhesive system can be recommended for the cementation.


2020 ◽  
pp. 232020682097597
Author(s):  
Ece Irem Oguz ◽  
Mehmet Ali Kılıçarslan ◽  
Merve Erdog˘ Özgür ◽  
Kaan Orhan ◽  
Sohaib Shujaat

Aim: To compare the marginal adaptation of crowns fabricated by using three different resin-ceramic computer-aided design/computer-aided manufacturing (CAD/CAM) materials. Materials and Methods: Crowns fabricated from three different resin-ceramic CAD/CAM blocks, applied on a typodont premolar (#14), were tested with regard to marginal adaptation, in this in vitro study. The typodont maxillary first premolar was prepared to serve as the master die and digitized with an intraoral scanner. The same virtual crown design was used to fabricate all specimens. Forty-eight crowns were fabricated from the same virtual crown design using three different CAD/CAM resin-ceramic blocks as follows ( n = 16): Lava Ultimate (LU), GC Cerasmart (GC), Vita Enamic (VE). Master die and crowns were scanned with a laboratory scanner and three-dimensional data were transferred into three-matic software. The software calculated the mean of the marginal discrepancy (MD) for each crown in negative and positive values, representing under and over estimation of the crown margin, respectively. A marginal discrepancy index (MDI) was obtained for each group using negative and positive MDs. All data were statistically analyzed using one-way analysis of variance and Tukey’s honest significance test ( α = 0.05). Results: The analysis of variance showed no statistical differences between materials regarding the negative and positive MDs ( P > .05). The MDI for LU was lower than GC and VE ( P < .05). Conclusion: The marginal adaptation of different resin-ceramic materials was different with regard to MDI values. Nevertheless, the MD values of all groups were within the clinically acceptable range.


2015 ◽  
Vol 40 (3) ◽  
pp. E83-E91 ◽  
Author(s):  
MA Bottino ◽  
F Campos ◽  
NC Ramos ◽  
MP Rippe ◽  
LF Valandro ◽  
...  

SUMMARY The aim of this study was to evaluate the internal fit, marginal adaptation, and bond strengths of inlays made of computer-aided design/computer-aided manufacturing feldspathic ceramic and polymer-infiltrated ceramic. Twenty molars were randomly selected and prepared to receive inlays that were milled from both materials. Before cementation, internal fit was achieved using the replica technique by molding the internal surface with addition silicone and measuring the cement thicknesses of the pulpal and axial walls. Marginal adaptation was measured on the occlusal and proximal margins of the replica. The inlays were then cemented using resin cement (Panavia F2.0) and subjected to two million thermomechanical cycles in water (200 N load and 3.8-Hz frequency). The restored teeth were then cut into beams, using a lathe, for microtensile testing. The contact angles, marginal integrity, and surface patterns after etching were also observed. Statistical analysis was performed using two-way repeated measures analysis of variance (p&lt;0.05), the Tukey test for internal fit and marginal adaptation, and the Student t-test for bond strength. The failure types (adhesive or cohesive) were classified on each fractured beam. The results showed that the misfit of the pulpal walls (p=0.0002) and the marginal adaptation (p=0.0001) of the feldspathic ceramic were significantly higher when compared to those of the polymer-infiltrated ceramic, while the bond strength values of the former were higher when compared to those of the latter. The contact angle of the polymer-infiltrated ceramic was also higher. In the present study, the hybrid ceramic presented improved internal and marginal adaptation, but the bond strengths were higher for the feldspathic ceramic.


2018 ◽  
Vol 12 (01) ◽  
pp. 123-128
Author(s):  
Fabio Kricheldorf ◽  
Cleuber Rodrigo de Souza Bueno ◽  
Wilson da Silva Amaral ◽  
Joel Ferreira Santiago Junior ◽  
Hugo Nary Filho

ABSTRACT Objective: The objective of this study is to compare the marginal adaptation of feldspathic porcelain crowns using two computer-aided design/computer-aided manufacturing systems, one of them is open and the other is closed. Materials and Methods: Twenty identical titanium abutments were divided into two groups: open system (OS), where ceramic crowns were created using varied equipment and software, and closed system (CS), where ceramic crowns were created using the CEREC system. Through optical microscopy analysis, we assess the marginal adaptation of the prosthetic interfaces. The data were subjected to the distribution of normality and variance. The i-test was used for the analysis of the comparison factor between the groups, and the one-way ANOVA was used to compare the variance of crown analysis regions within the group. A significance level of 5% was considered for the analyses. Results: There was a significant difference between the systems (P = 0.007), with the CS group having the higher mean (23.75 pm ± 3.05) of marginal discrepancy when compared to the open group (17.94 pm ± 4.77). Furthermore, there were no differences in marginal discrepancy between the different points between the groups (P > 0.05). Conclusions: The studied groups presented results within the requirements set out in the literature. However, the OS used presented better results in marginal adaptation.


Folia Medica ◽  
2020 ◽  
Vol 62 (3) ◽  
pp. 546-552
Author(s):  
Aleksandra Pecheva ◽  
Kostadin Georgiev ◽  
Snezhana Tsanova ◽  
Ralitsa Raycheva

Introduction: One method to evaluate the clinical success of cemented restorations is measuring the marginal adaptation. There is a correlation between the fitting of the restoration and problems caused by clinically undetectable passage of bacteria between the tooth structure and the veneer. Aim: To evaluate in comparison the marginal adaptation of veneers produced via CAD/CAM and press technique. Materials and methods: 32 extracted incisors are divided into two equal-number groups (n=16) according to the production technique &ndash; CAD/CAM zirconium veneers and press-ceramic veneers. Cut sections are examined under a SEM magnification. Marginal accuracy is measured as the distance between the finish line of the tooth and the margin of the veneer at eight fixed locations. Results: The mean values of marginal gap of group 1 are: external adaptation &ndash; 79.88&plusmn;3.71 &micro;m; internal adaptation &ndash; 79.14&plusmn;15.70 &micro;m; cervical adaptation &ndash; 82.39&plusmn;28.55 &micro;m; incisal adaptation &ndash; 86.85&plusmn;21.72 &micro;m. The mean values of marginal gap of group 2 are: external adaptation &ndash; 100.31&plusmn;2.16 &micro;m; for internal adaptation &ndash; 101.01&plusmn;12.51 &micro;m; cervical adaptation &ndash; 91.55&plusmn;3.31 &micro;m; incisal adaptation &ndash; 93.76&plusmn;2.54 &micro;m. Conclusions: Veneers produced via CAD/CAM technology have better fit at the external and internal marginal wall. There is no statistically significant difference between the gaps at the cervical and the incisal areas.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Jae-Hong Kim ◽  
Seunghan Oh ◽  
Soo-Hyuk Uhm

The aim of this study is to quantify the effect of the crystallization process on lithium disilicate ceramic crowns fabricated using a computer-aided design/computer-aided manufacturing (CAD/CAM) system and to determine whether the effect of crystallization is clinically acceptable by comparing values of fit before and after the crystallization process. The mandibular right first molar was selected as the abutment for the experiments. Fifteen working models were prepared. Lithium disilicate crowns appropriate for each abutment were prepared using a commercial CAD/CAM system. Gaps in the marginal area and 4 internal areas of each crown were measured twice—before and after crystallization—using the silicone replica technique. The mean values of fit before and after crystallization were analyzed using a pairedt-test to examine whether the conversion that occurred during crystallization affected marginal and internal gaps (α=0.05). Gaps increased in the marginal area and decreased in the internal areas after crystallization. There were statistically significant differences in all of the investigated areas (P<0.05). None of the values for marginal and internal fit of lithium disilicate CAD/CAM crowns after crystallization exceeded 120μm, which is the clinically acceptable threshold.


2020 ◽  
Author(s):  
Hendrik Naujokat ◽  
Klaas Loger ◽  
Juliane Schulz ◽  
Yahya Açil ◽  
Jörg Wiltfang

Aim: This study aimed to evaluate two different vascularized bone flap scaffolds and the impact of two barrier membranes for the reconstruction of critical-size bone defects. Materials & methods: 3D-printed scaffolds of biodegradable calcium phosphate and bioinert titanium were loaded with rhBMP-2 bone marrow aspirate, wrapped by a collagen membrane or a periosteum transplant and implanted into the greater omentum of miniature pigs. Results: Histological evaluation demonstrated significant bone formation within the first 8 weeks in both scaffolds. The periosteum transplant led to enhanced bone formation and a homogenous distribution in the scaffolds. The omentum tissue grew out a robust vascular supply. Conclusion: Endocultivation using 3D-printed scaffolds in the greater omentum is a very promising approach in defect-specific bone tissue regeneration.


Author(s):  
Abdulrahman Alhaddad ◽  
Samar Abuzinadah ◽  
Abdullah Al-Otaibi ◽  
Abrar Alotaibi ◽  
Mohsen Alfkih ◽  
...  

Background: Zirconia-based restorations have become more popular in dentistry during the last two decades. Patients choose metal-free restorations, preferring materials with similar attributes to natural teeth and similar light scattering characteristics, resulting in a nice esthetic appearance. Restoring a root canal treated teeth is one of the hot topics today. endo crown materials can be either; feldspathic, glass-ceramic, monolithic hybrid ceramic or composite material. Considering the marginal gap of endocrown, an important cause of failure of treatment, the current study evaluated the marginal gap of CAD‐CAM concocted endo-crowns. Materials and Methods: This research is an analysis systemic review study was conducted between January 2020 and October 2021. We followed the PRISMA principles and recorded this systematic review using the PROSPERO database to find and identify published literature related to the marginal adaptation of CAD-CAM-fabricated endocrown. The search will include all relevant articles through the end of 2021. Finally, 24 papers on marginal clearance and fracture resistance in coronary arteries were reviewed. Results: The electronic database search yielded 98 studies that were relevant. After cross-referencing, further seven studies were added. After a full-text analysis and duplicate reduction, 74 of the 98 articles were eliminated. 5 clinical (prospective) studies, 19 in vitro studies were found. Conclusion: This analysis of the recent literature on the marginal seating integrity and fracture resistance of CAD/CAM made-up endo-crowns showed that the endo-crown had superior marginal seating integrity than classical full crown. CAM/CAM showed statistically significant higher mean fracture resistance than MAD/MAM.


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