ABSTRACT
PURPOSE: To evaluate the fracture resistance of a newer lithium disilicate abutment material. MATERIALS AND METHODS: A premolar-shaped implant crown was designed using CAD/CAM software, and four groups of implant and crown combinations were milled: (1) lithium-disilicate hybrid-abutment crown; (2) "screwmentable" lithium-disilicate hybrid abutment/lithium-disilicate crown with screw channel; (3) lithium-disilicate hybrid abutment/lithium-disilicate crown; and (4) zirconia hybrid abutment/lithium-disilicate crown (control). The specimens were cemented to a titanium-base implant system, subjected to thermocycling and cyclic loading, and fractured in a material testing device. RESULTS: The lithium-disilicate hybrid-abutment crown had significantly greater fracture load than all the other groups, which were not significantly different from each other. CONCLUSIONS: Based on fracture load, the new lithium-disilicate hybrid-abutment material may serve as a viable alternative to the use of zirconia as a hybrid-abutment material.
Subject(s)
Crowns , Dental Implant-Abutment Design , Dental Porcelain/chemistry , Dental Prosthesis Design , Dental Restoration Failure , Titanium/chemistry , Zirconium/chemistry , Computer-Aided Design , Dental Stress Analysis , Materials TestingABSTRACT
PURPOSE: To determine the effect of new universal bonding agents on the bond strength of dual-cure resin cements to dentin. METHODS: 140 extracted human third molars were mounted in dental stone and sectioned with a saw to remove coronal tooth structure. The teeth were randomly divided into seven groups of 20, based on the use of five universal bonding agents (All-Bond Universal; FuturaBond U; Prime&Bond Elect; Scotchbond Universal; Clearfil Universal) compared to two self-etch bonding agents (Clearfil SE Bond and Clearfil SE Bond 2). Each group was further divided into two equal subgroups of 10 specimens each with each subgroup tested with either self- or light-cure activation of the dual-cure resin cement (Calibra). The bonding agent was applied per manufacturers' instructions to the dentin surface of each specimen. The specimens were placed into a jig and resin cement was inserted into the mold to a height of 3-4 mm and light cured. Specimens were stored for 24 hours in 37 degrees C distilled water and tested in shear in a universal testing machine. A mean shear bond strength value (MPa) and standard deviation was determined per group. RESULTS: Except for Clearfil Universal, the new simplified universal bonding agents resulted in significantly lower shear bond strength of the resin cement to dentin than the two-step, self-etching bonding agents Clearfil SE Bond or Clearfil SE Bond 2.
Subject(s)
Composite Resins , Dental Bonding/methods , Dentin/chemistryABSTRACT
The study evaluated the effect of salivary-contaminant removal methods on the bond strength of resin cement to hydrofluoric acid-etched ceramic. Treatment with a new cleaning paste resulted in bond strengths not significantly different from those obtained in phosphoric acid-treated, hydrofluoric acid-treated, and uncontaminated control groups; thus the paste may be considered an alternative to phosphoric acid or hydrofluoric acid for removal of salivary contaminants.
Subject(s)
Acid Etching, Dental/methods , Dental Bonding/methods , Resin Cements/therapeutic use , Ceramics/therapeutic use , Dental Porcelain/therapeutic use , Dental Stress Analysis , Humans , Saliva/metabolismABSTRACT
The application and incomplete removal of a computer-aided design/computer-aided manufacture imaging powder may affect the dentin surface prior to bonding a ceramic restoration. The purpose of this study was to compare the effect of imaging powder residue on the shear bond strength of a self-adhesive resin cement to dentin. Mounted human third molars were sectioned coronally with a diamond saw to expose the dentin, which was then prepared with a diamond bur mounted in a custom jig. The dentin surface was sprayed with 3 different imaging powders. The 3 powder groups were then divided into 3 subgroups based on the method of powder removal: no rinse, 1-second rinse, and 10-second rinse. A control group was created that had no application of imaging powder. A self-adhesive resin cement was bonded to the surfaces and loaded to failure in a universal testing machine after 24 hours of storage. Data was analyzed with Kruskal-Wallis and Mann-Whitney nonparametric tests. The bonding to dentin surfaces of the powder groups that were rinsed for 1 or 10 seconds were not significantly different from each other or the nonpowdered control. The type of imaging powder did not significantly affect the bond strength. The nonrinsed powdered dentin surface had a significant reduction in bond strength compared to both the control and the rinsed powdered surfaces.
Subject(s)
Dental Bonding , Dental Impression Technique/adverse effects , Resin Cements/metabolism , Computer-Aided Design , Dental Bonding/methods , Dental Materials/therapeutic use , Dental Restoration Failure , Dental Stress Analysis , Humans , Powders/therapeutic useABSTRACT
The esthetics and function of a tissue borne, implant retained overdenture are two of the most important factors that define a patient's acceptance of the prosthesis. In this clinical report, an existing implant overdenture, which was esthetically acceptable to the patient but which had no incorporated retentive components in the substructure framework, was retrofitted to a newly designed and fabricated implant framework. The added retentive components on the new framework increased the patient's overall masticatory function, reduced the frequency of dental visits, and allowed the patient to retain the original overdenture.
