The restoration of endodontically treated teeth (ETT) with more than one cusp missing and thin remaining walls is challenging for the general practitioner. The use of posts combined with full coverage restorations is a well-established approach, yet not following the minimal invasive principles of adhesive dentistry. Endocrowns are indirect monoblock restorations that use the pulp chamber of the ETT for retention. In this study the fabrication of 4 endocrowns and their clinical performance will be discussed. Two clinical cases include computer-aided design/computer-aided manufacturing manufactured molar endocrowns (one feldspathic ceramic and one hybrid composite-ceramic restoration) and the other two are dental laboratory manufactured resin composite premolar endocrown restorations. The modified United States Public Health Service criteria were used to assess the clinical behavior of the restorations at different follow up periods. Endocrown restorations present a satisfactory clinical alternative, either by the use of resin composite or glass ceramic and hybrid materials. Specific guidelines with minimal alterations should be followed for an endocrown restoration to be successful. Due to limited evidence regarding the long term evaluation of this restorative technique, a careful selection of cases should be applied.
Objectives:To evaluate the polymerization efficiency of bulk fill resin-based composites (RBCs) and how their composition, temperature and post-irradiation polymerization influence the results. Methods and Materials: Eight bulk fill RBCs were investigated. Five specimens for each material were prepared for Vickers hardness measurements. The measurements were performed in three depths from the top of the surface of the specimens (0, 2 or 4 mm) immediately and 24 h after polymerization and for the highly viscous bulk fill RBCs after preheating at 54 o C. Statistical analysis was performed using one-way ANOVA and Tukey post hoc tests at a=0.05. Results: As the depth increases microhardness values reduce. The Vickers hardness measurements 24 h after photo-polymerization revealed higher values compared to those obtained immediately after photo-polymerization (p<0.05). There was an increase in microhardness of the RBC materials when preheated at 54 o C in comparison with the room temperature specimens (p<0.05).Conclusions: Polymerization efficiency of bulk fill RBCs is affected by their composition and increases with temperature and post-irradiation polymerization.
This paper details a novel method to improve wear resistance of dental glass ionomer cement (GIC) restorations. The purpose of this in vitro study was to evaluate the effect of a calcium chloride (CaCl) solution treatment on surface hardness, surface roughness, compressive strength, water sorption and solubility of three conventional glass ionomer cements (GICs). Additionally, the changes of the Ca composition and morphology of the surface of the tested GICs were also investigated. The experimental groups of the study were: Group 1 (control) specimens after mixing were left in the mold to set without any treatment for 5 min; Group 2 specimens were left in the mold to set for 5 min and then each specimen was immersed in 10 ml of 42.7 wt% CaCl solution for 60 s. Statistical analysis was performed using one-way ANOVA and Tukey post hoc tests (a = 0.05). Calcium chloride solution treatment increased surface hardness of the GICs compared to control groups (P < 0.05), while surface roughness and compressive strength did not change after the treatment (P > 0.05). Reduction in water sorption and solubility was detected but not in all CaCl solution-treatment groups. No alterations were observed in surface morphology of the GICs, while surface calcium composition was increased after the treatment (P < 0.05). The use of a CaCl solution immediately after initial setting of GICs may be advantageous for some properties of the materials and possibly leads to improved prognosis and wear resistance of their restorations.
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