Marginal, Internal Fit and Microleakage of Zirconia Infrastructures: An In-Vitro Study

Abstract

This in-vitro study compared the marginal and internal fit and also the microleakage of zirconia infrastructures (Procera All-Zircon, Cercon Smart Ceramics) in contrast to heat-pressed ones (Empress 2).Thirty maxillary premolars (n=30) were divided into three groups (n=10) and prepared with individual chamfer preparations by using the silicone index method. Plaster dies of 10 individual preparations were allocated to each coping fabrication method of computer-aided design and computer-aided manufacturing (Procera), computer-aided manufacturing (Cercon) and heat pressing (Empress 2) as the control. All the specimens were kept in distilled water at room temperature for four weeks after cementation with dual-curing resin cement (Variolink II, Ivoclar-Vivadent). They were then thermocycled between 5°C to 55°C for 5000 cycles with a 20-second dwell time and immersed in 0.5% basic fuchsin for 48 hours. The cemented specimens were separated into two halves vertically in the midvestibulo-palatal direction. The specimens were examined under a computer-aided stereomicroscope to evaluate both the internal and marginal fit. Marginal and internal gap widths were measured at 100× magnification. The specimens were evaluated for microleakage under a stereomicroscope at 100 × magnification. Selected specimens from each group were also examined using a scanning electron microscope. Fitting accuracy data were analyzed statistically with the Welch test and the Post-hoc Dunnett C-test (p<0.05). The microleakage data were analyzed with the Kruskal-Wallis test. Special software (SPSS/PC+ Version 10.0, SPSS, Chicago, IL, USA) was used for statistical evaluations.Differences between the marginal and internal fitting accuracy of the tested non-veneered infrastructures were found to be statistically significant (p<0.05). However, there were no significant differences in microleakage among the groups (p=0.273).

Multifactorial analysis of the impact of different manufacturing processes on the marginal fit of zirconia copings

“…For the manual adapted copings, the mean marginal gaps varied from 54 to 59.9 μm. This is in accordance with marginal gaps reported for CAD/ CAM-generated zirconia copings in other studies, in which marginal gaps ranged from 24 to 110 μm 6,11,14,15,31) . The large variation in the reported mean values can be explained by a number of infl uencing factors, including CAD/CAM components and differences between presintered and post-sintered milling of the zirconia blank.…”

“…The large variation in the reported mean values can be explained by a number of infl uencing factors, including CAD/CAM components and differences between presintered and post-sintered milling of the zirconia blank. In in vitro studies using the same CAD/CAM system (Cercon) such as the present study, mean values for marginal openings were reported to range from 38 to 66 μm 11,27,31) . The variation in reported mean values of samples derived from the same CAD/CAM system can be explained by differences in study designs and measurement techniques, including evaluations of cemented or non-cemented crowns; various preparation designs of abutments; different types of microscope/ magnifi cations used for the measurements; and the location and quantity of single measurements 6) .…”

Evaluation of marginal fit and microleakage of monolithic zirconia crowns cemented by bio-active and glass ionomer cements: In vitro study

“…Penetration of the dye depends on molecular size of the dye, molecular polarity, surface interface and time. Both dye and ink penetration provides a similar sealing ability [33]. In the present study, no significant difference in the vertical marginal gap values were found between the two tested groups before or after thermocycling.…”

“…In order to assess microleakage, all teeth were covered with nail polish varnish apical to the margin of the restoration by 1 mm to prevent any dye penetration except at the tooth/crown interface. Then, the teeth were immersed in 0.5% basic fuchsin dye for 48 hours [33] at 37°C. By using Isomet saw (Buehler Isomet saw 4000), the crowns were sectioned vertically in a buccolingual direction with low-speed cutting saw of 0.7 mm thickness abrasive disc, at speed of 2500 rpm, under continuous watercoolant.…”

Marginal Adaptation of CAD/CAM All‐Ceramic Crowns Made by Different Impression Methods: A Literature Review

“…Based on these limited data, it can be concluded that the type of ceramic material could be effective on marginal gap, and IPS e.max ceramic material might have a smaller marginal gap as compared to zirconia; however, using a CEREC extraoral scanner, posterior restorations with shoulder preparation showed 29.98 μm and 13.15 μm marginal gap using glass‐infiltrated zirconia‐toughened alumina (In‐Ceram Zr) and tetragonal zirconia (In‐Ceram YZ), respectively . In posterior restorations using a Cercon extraoral scanner, 43 μm and 70 μm marginal gaps were reported using zirconia cores.…”