الفهرس 
AbstractOnly 14 pages are availabe for public view
 |  | from | 185 |  |  |
| | | from | 185 | | |
Abstract
Objective: The aim of this study was to evaluate the impact of pre-heated two types of resin cements on the marginal and internal adaptation of lithium disilicate and zirconia restorations. Materials and methods: Eighty intact human maxillary premolars were selected for this study, prepared using computer aided design/computer aided manufacturing (CAD/CAM) for standardization of natural teeth preparation. Teeth were divided into two main groups according to the restorative materials used (n=40). group E: restored with monolithic IPS e.max Press and group Z: restored with monolithic Blu Zirkon. Each main group was subdivided into two subgroups (n=20) according to type of resin cement. group P: Panavia SA Plus self-adhesive resin cement and group L: G-CEM LinkForce adhesive resin cement. Each subgroup was divided into two equal subcategories (n=10) according to the pre-heating temperature of resin cement. group R: cement was applied at room temperature (25°C) and group H: cement was pre-heated at (54°C). Before cementation, vertical marginal discrepancies were measured at the margin of each restoration. Silicone replicas were obtained to measure marginal and internal discrepancies (µm) that was evaluated with stereomicroscope at 45X magnification. Vertical marginal discrepancies (µm) were evaluated 24 hours after final cementation and after artificial aging; 240,000 load cycles and 10,000 thermal cycles. Internal and marginal discrepancies (µm) were measured with stereomicroscope at 45X after sectioning the restorations bucco-palatally. The data were statistically analysed using Mann-Whitney U and Wilcoxon signed Rank test. Three-way ANOVA test was used for detection of combined effects on dependant outcome. Results: After cementation, significantly higher marginal discrepancies were noted in comparison with before cementation. Restorative materials and pre-heating temperature significantly affected on the marginal and internal adaptation. Resin cement types showed no significant effect on internal and marginal adaptation. Conclusions: Elevated pre-heated temperature of resin cements improved the marginal adaptation but not enhanced the internal adaptation. Resin cement type has no effect on the adaptation. Clinical Significance: To identify the influence of pre-heating resin cements and simulated oral condition on the marginal and internal adaptation of ceramic restorations.