Influence of Speed Sintering Protocol on Marginal Adaptation of High Translucent Zirconia Fixed Restorations

doi:10.21608/mjd.2020.200158

Influence of Speed Sintering Protocol on Marginal Adaptation of High Translucent Zirconia Fixed Restorations

Document Type : Original Article

10.21608/mjd.2020.200158

Abstract

Statement of problem:Is the speed sintering protocol harmfully affecting the marginal adaptation of high translucent zirconia crowns, or it is save to use in addition to saving time and electrical power comparing with conventional sintering protocols!
Objective: Studying the effect of speed sintering protocol on marginal adaptation of two types of high translucent zirconia crown restorations.
Materials and methods:Twenty extracted human maxillary premolars were randomly divided into two main groups according to type of zirconia material used, each tooth was received two similar crowns, one conventionally sintered, ‎the other was speed sintered. The two main groups (n=20): group (K); teeth were restored with KATANA STML crowns, and group (Z); teeth were restored with Zolid fx white crowns.Each group were further subdivided into two subgroups according to sintering protocols (n=10): (KC); conventionally sintered KATANA STML crowns, (KS); speed sintered KATANA STML crowns, (ZC) conventionally sintered Zolid fx white crowns, (ZS); speed sintered Zolid fx white crowns.
Each tooth was centrally embedded in epoxy resin block, and Standardized prepared using dental surveyor.
CAD-CAM work follow was applied to all the specimens, including: scanning, 3D designing, and milling of crowns.
All crowns were sintered using furnace (in-Fire HTC speed, Dentsply-sirona). Four different sintering protocols were applied according manufacture instructions of each subgroup.
Evaluation of marginal adaptation using silicon replica technique,each replica was measured at 25X power of magnification under stereo microscope.
One-way ANOVA test were used to detect significant differences which judged at (0.05) level.
Results: There was significant different between different zirconia materials (K and Z) with different sintering protocols (conventional and speed), at palatal finish line. The highest value of marginal discrepancy was at palatal finish line of (KS) subgroup (70.00±19.43 µm), while the lowest value was recorded at buccal finish line of (ZS) subgroup (45.00±9.71 µm).
Conclusions:1-The marginal adaptation of speed and conventionally sintered high translucent zirconia crowns were within the clinically accepted range.
2- Speed sintering protocol did not have harmful effect on the integrity of marginal adaptation of zolid fx crowns.