scholarly journals Effect of CAD/CAM Ceramic Thickness on Shade Masking Ability of Discolored Teeth: In Vitro Study

Author(s):  
Passent Ellakany ◽  
Marwa Madi ◽  
Nourhan M. Aly ◽  
Zainb S. Al-Aql ◽  
Maher AlGhamdi ◽  
...  

Shade matching is a common challenge that dentists face during fabrication of esthetic dental restoration. Thus, the aim of the current study was to assess the masking ability of two types of CAD/CAM ceramics for gaining high esthetic prosthesis. This in vitro study used a total sample size of 66 lithium disilicate (LD) and leucite reinforced (LR) CAD/CAM ceramics sub-grouped into three thicknesses: 0.5, 1, and 1.5 mm. Nine shades of natural dentin die materials were prepared as a replica of the underlying tooth structure. The difference in color (ΔE) and translucency parameter (TP) were assessed for both tested ceramics at the three thicknesses. One-way ANOVA was performed to compare the three thicknesses of each ceramic, followed by multiple pairwise comparisons between both ceramics. LR had significantly higher ΔE than LD at all thicknesses used unlike the case in TP. Thickness of 0.5 mm exhibited the highest ΔE and TP, while 1.5 mm thickness showed the lowest ΔE and TP in both ceramics. Increase in ceramic thickness had a great impact on both color masking ability of the underlying tooth structure and its translucency. The higher the ceramic thickness, the better the masking ability and the lower the translucency was reported.

2021 ◽  
Vol 11 (5) ◽  
pp. 2339
Author(s):  
Joanna Metlerska ◽  
Till Dammaschke ◽  
Mariusz Lipski ◽  
Irini Fagogeni ◽  
Anna Machoy-Mokrzyńska ◽  
...  

The aim of the present in vitro study was to investigate the effects of 10% and 40% citric acid (CA) on the color of calcium silicate–based cements (CSCs) in comparison to the effects of common root canal irrigants. Samples of six CSCs (n = 6)—ProRoot MTA (Dentsply, Tulsa, OK, USA), Biodentine (Septodont, Saint-Maur-des-Fossés, France), MTA Plus (Avalon Biomed Inc, by Prevest Denpro Limited, Jammu, India), MTA Repair HP (Angelus, Londrina, PR, Brazil), Ortho MTA (BioMTA, Seoul, Korea), and Retro MTA (BioMTA, Seoul, Korea)—were immersed in 10% and 40% CA as well as 15% EDTA, 2% NaOCl, 2% CHX, and 0.9% NaCl for 15 min, 1 h, and 24 h. ΔE values, representing the difference between the final and baseline values of the color components, were then determined using a VITA Easyshade Compact 5.0 spectrophotometer. Naked-eye evaluation of the changes in color and structures of the materials was performed using our own scale. Upon immersion of the materials in both 10% and 40% CA, there were statistically significant differences between spectrophotometric color measurement results for all CSCs (P < 0.05). However, CA does not cause dark discoloration, observable with the naked eye, of any of the materials, such as NaOCl and CHX. Significant statistical differences were also found between all CSCs in terms of submersion duration (P < 0.05). CA, which could be an alternative to EDTA use, caused greater CSCs discoloration and changed some of their structures. Unless required by the therapeutic procedure, clinicians should pay attention to the fact that the irrigant may affect the CSCs discoloration and minimize the contact time of irrigant with CSCs.


2021 ◽  
Vol 11 (2) ◽  
pp. 857
Author(s):  
Keunbada Son ◽  
Kyu-Bok Lee

The purpose of this in vitro study was to evaluate marginal and internal fits of ceramic crowns fabricated with chairside computer-aided design and manufacturing (CAD/CAM) systems. An experimental model based on ISO 12836:2015 was digitally scanned with different intraoral scanners (Omnicam (CEREC), EZIS PO (DDS), and CS3500 (Carestream)). Ceramic crowns were fabricated using the CAD/CAM process recommended by each system (CEREC, EZIS, and Carestream systems; N = 15). The 3-dimensional (3D) marginal and internal fit of each ceramic crown was measured using a 3D inspection software (Geomagic control X). Differences among the systems and various measurements were evaluated using the Kruskal–Wallis test. Statistically significant differences were validated using pairwise comparisons (α = 0.05). Occlusal gaps in the CEREC, EZIS, and Carestream groups were 113.0, 161.3, and 438.2 µm, respectively (p < 0.001). The axial gaps were 83.4, 78.0, and 107.9 µm, respectively. The marginal gaps were 77.8, 99.3, and 60.6 µm, respectively, and the whole gaps were 85.9, 107.3, and 214.0 µm, respectively. Significant differences were observed with the EZIS system compared with the other two systems in terms of the marginal gap sizes. The CEREC system showed no significant differences among the four measured regions. However, the EZIS and Carestream systems did show a statistically significant difference (p < 0.05). All three systems were judged to be capable of fabricating clinically acceptable prostheses, because the marginal gap, which is the most important factor in the marginal fit of prostheses, was recorded to be below 100 µm in all three systems.


2021 ◽  
Vol 24 (6) ◽  
pp. 828
Author(s):  
A Robaian ◽  
A Maawadh ◽  
ZI Alghomlas ◽  
AM Alqahtani ◽  
TA Alothman ◽  
...  

2021 ◽  
pp. 66-68
Author(s):  
Rakesh Pyla ◽  
Jai Kiran Killada ◽  
V Raja Sekhar

Aim:Endodontic retreatment is a procedure that removes the lling materials from the root canals followed by their cleaning, shaping and obturation. This in-vitro study aimed to compare and evaluate the ability of various essential oils as solvents in dissolving gutta-percha, epoxy resin, and zinc oxide eugenol (ZOE) cements. Materials and methods: A total of 28 cylindrical specimens in each group ZOE, epoxy resin, 28 ISO size 40 gutta-percha cones were prepared and divided into four groups for immersion in the different solvents, i.e. lemon oil, citronella oil, lavender oil, and TCE(Tetrachloroethylene (control)) for 5 minutes. The obturating materials dissolution in the solvents were obtained by the difference between the pre-immersion original weight and the post-immersion weight on a digital analytical scale. Data were statistically analysed by a paired t-test and Analysis of Variance (ANOVA) (p < 0.05). Results: Order of efcacy of dissolution of essential oils was found to be lemon oil > Citronella oil > Lavender oil and was highly signicant (p < 0.01). In all the solvents, Gutta-percha showed maximum dissolution (Fvalue:149.56) followed by ZOE(89.07 ) and resin sealer least (23.86). Conclusion: It can be concluded that the lemon oil can be used as a solvent for dissolving obturating materials.


2018 ◽  
Vol 12 (1) ◽  
pp. 638-646 ◽  
Author(s):  
Massimo Amato ◽  
Alfredo Iandolo ◽  
Giuseppe Pantaleo ◽  
Dina Abtellatif ◽  
Michele Simeone ◽  
...  

Aim: The aim of this study was to evaluate the efficacy of the IG-file, a new instrument designed for apical diameter gauging. Materials and Methods: After shaping with F1 Universal Protaper, 60 roots were randomly divided into two groups and assigned to two operators, One Expert in Endodontics (EO) and One Unexpert (UO). In each sample, after canal curvatures have been detected, the apical diameters were measured with the IG-file and the K-NiTi. The results were compared with the reference value obtained by retrograde apical gauging. The data were statistically analyzed. Results: Among 60 samples, 10% of errors were recorded when the IG-files were used; in the K-NiTi group the incorrect measurements were 70%. In both groups (expert and unexpert) the IG-file measurements were more accurate than the K-NiTi (90 vs 33 and 90 vs 26,7). The differences were statistically significant. In curved canals, the difference between measurement rates performed with both instruments was statistically significant (85,7% IG-file vs 28,6% K-NiTi) as well as for the samples without curvatures (92,3% IG file vs 30,8% NiTi file). In root canals without curvatures overestimation errors in K-NiTi file group are more frequent than underestimation errors. This difference was statistically significant. Conclusion: A proper gauging of the apical diameter has a key role in endodontic therapy; an incorrect measurement can lead to clinical failures. This “in vitro” study highlights that IG-file improves measurement accuracy independently from clinician experience. Furthermore, in curved canals, the IG-file is more accurate than K-NiTi.


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