Marginal fit of monolithic versus layered zirconia crowns assessed with 2 marginal gap methods.

Statement Of Problem: Zirconia can be used either monolithically or veneered with porcelain. However, whether veneering zirconia affects marginal fit is unclear.

Purpose: The purpose of this in vitro study was to evaluate the marginal fit of the monolithic and layered zirconia prostheses using 2 different assessment methods.

Fracture Resistance of Zirconia Restorations with Four Different Framework Designs.

This study assessed the fracture resistance of zirconia crowns with four framework designs, fabricated by computer-aided design/computer-aided manufacturing (CAD/CAM) technology. In this experimental study, a maxillary central incisor was prepared and scanned with a CAD/CAM scanner, and 40 frameworks with 4 designs (N=10) were fabricated as follows: simple core, dentine core with a design similar to dentine, 3mm trestle design collar in the lingual aspect with proximal buttresses, and monolithic or full-contour. After porcelain applying and 20h immersion in distilled water (37°C), crowns were cemented on metal dies using zinc phosphate cement.

Color match of ultra-translucency multilayer zirconia restorations with different designs and backgrounds.

Purpose: The purpose of this in vitro study was to assess the color match of ultra-translucency multilayer zirconia restorations with different designs and backgrounds.

Materials And Methods: Thirty ultra-translucency multilayer zirconia crown specimens were made in VITA classical shade B2 for a prepared maxillary central incisor. The specimens were divided into three groups based on the restoration design: veneered zirconia with a trestle design (VZT), veneered zirconia with a dentin core design (VZD), and full-contour zirconia (FCZ).

Tensile Bond Strength and Retention of Three Types of Ceramic Endocrowns.

Statement Of The Problem: By development of adhesive dentistry and noble mechanical strength of ceramics, reconstruction of posterior teeth with partial coverage restorations such as ceramic endocrowns is possible. Different ceramics may show different mechanical properties which should be investigated.

Purpose: The aim of this experimental study was to compare the tensile bond strength of endocrowns made by CAD-CAM using 3 types of ceramics.

External versus Endoscopic Dacryocystorhinostomy for Primary Acquired Nasolacrimal Duct Obstruction.

Purpose: The purpose of the study is to compare the surgical outcomes and success rates of external dacryocystorhinostomy (EX-DCR) versus endoscopic endonasal DCR (EN-DCR) for the treatment of primary acquired nasolacrimal duct obstruction (PANDO).

Methods: This retrospective nonrandomized study was conducted at Farabi Eye Hospital and Noor Eye Hospital, Iran. A review of electronic medical records of all patients with PANDO who underwent EX-DCR or EN-DCR between January 2016 and 2018 was carried out.