Roya Zandparsa

Tufts University | Tufts · Department of Prosthodontics and Operative Dentistry

Purpose: To compare the marginal adaptation of 3-unit zirconia fixed dental prostheses (FDPs) obtained from intraoral digital scanners (Lava True Definition, Cadent iTero), scanning of a conventional silicone impression, and the resulting master cast with an extraoral scanner (3Shape lab scanner). Materials and methods: One reference model was f...

The purpose of this in vitro study was to evaluate and compare the effectiveness of different surface cleaning methods on the shear bond strength (SBS) of zirconia ceramic surfaces. Seventy polished and cleaned zirconia disk specimens of 8 mm in diameter and 3.4 mm in thickness were immersed in fresh saliva. They were then pressed into a freshly mi...

Statement of problem: The wear of tooth structure opposing different advanced dental ceramic systems requires investigation. Purpose: The purpose of this in vitro study was to compare the wear of advanced ceramic systems against human enamel antagonists. Material and methods: Four ceramic systems (IPS e.max Press, IPS e.max CAD, Noritake Super...

The purpose of part II of this in vitro study was to compare the fracture load of two-piece zirconia custom abutments with different thicknesses and angulations. Forty zirconia custom abutments were divided into four groups as follows: group A1: 0.7 mm thickness and 0° angulations; group A2: 0.7 mm thickness and 15° angulations; group B1: 1 mm thic...

PurposeThe purpose of this in vitro study was to evaluate the effects of four surface treatments and two resin cements on the repair bond strength of a ceramic primer.Materials and Methods Eighty-eight pairs of disks (10 and 5 mm in diameter, 3 mm thickness) were prepared from heat-pressed feldspar ceramics (GC Initial IQ). After being stored in mu...

The accuracy of chairside computer-aided design and computer-aided manufacturing (CAD/CAM) restorations is questionable, and the effect of the die spacer settings is not well stated in the literature. The purpose of the study was to evaluate the marginal and internal adaptation of E4D crowns fabricated with different spacer thicknesses and to compa...

Navigation technology is applied successfully in oral and maxillofacial surgery. Laser beams are used for caries removal. With nanodentistry, it is possible to maintain comprehensive oral health care. Nanorobots induce oral analgesia, desensitize teeth, and manipulate the tissue. They can also be used for preventive, restorative, and curative proce...

Bioceramics have been adopted in dental restorations for implants, bridges, inlays, onlays, and all-ceramic crowns. Dental bioceramics include glass ceramics, reinforced porcelains, zirconias, aluminas, fiber-reinforced ceramic composites, and multilayered ceramic structures. The process of additive manufacturing is ideally suited to dentistry. Mod...

The purpose of this in vitro study was to compare the fracture load of one-piece zirconia custom abutments with different thicknesses and angulations. Forty zirconia custom abutments were divided into four groups. Group A-1 and group B-1 simulated a clinical situation with an ideal implant position, which allows for the use of straight zirconia cus...

Fabricating implant definitive casts with CAD/CAM technology (Robocasts) from coded healing abutment impressions represents a simpler and innovative alternative to conventional implant impression techniques. However, information about the accuracy of the impressions and the resultant definitive casts is limited. The purpose of the study was to eval...

The purpose of this study was to compare the effect of variations in translucency and background on color differences (ΔE) for different shades of computer-aided design and computer-aided manufacturing (CAD/CAM) lithium disilicate glass ceramics. A pilot study suggested n = 10 as an appropriate sample size for the number of lithium disilicate glass...

The purpose of this in vitro study was to compare the shear bond strength of an airborne-particle abraded zirconia, an acid-etched zirconia (Piranha solution), an Alloy Primer treated zirconia, and a silaned zirconia to enamel, all bonded with a phosphate-methacrylate resin luting agent. Seventy extracted intact human molars were collected, cleaned...

Objective: Prostheses obtained from digital impressions are now increasingly used in dentistry, although follow-up data are limited. The aim of this study was to evaluate the four-year clinical results of the installation of 21 Zirconia fused to porcelain crowns generated by digital impressions. Method: This study followed 4 patients (a man and 3...

Purpose: This in vitro study aimed to determine the ability of three resin cements to retain zirconia copings under two clinically simulated conditions. Materials and methods: Extracted human molars (72) were collected, cleaned, and divided into two groups. All teeth were prepared with a 15° total convergence angle for group 1 and a 30° total co...

  Color-matching of the cervical area between natural teeth and different crown prostheses is a common clinical problem.   The purpose of this study was to compare the color of the cervical region of five commercially available crown systems to an extracted natural tooth and to each other.   The color of the cervical region of an extracted maxillar...

Objectives: The purpose of this in vitro study was to determine the ability of three different resin cements to retain zirconia copings under two clinically simulated conditions. Methods: Seventy-two human molars were divided into two groups. All teeth were prepared with a 15 degree total convergence angles for group one and a 30 degree total con...

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Many different surface treatments have been used to increase the bond strength of noble and base metal alloys to enamel, but only a few have been studied. The purpose of this in vitro study was to compare the tensile bond strength of a tin-plated noble alloy, an Alloy Primer-treated noble alloy, and an airborne particle-abraded base metal alloy, al...