The clinical significance of mechanical properties in retentive posts.

When selecting dental materials for use in the permanent restoration of severely broken down teeth, clinicians must choose a material with the optimal mechanical and physical properties for that particular application, with esthetics as a secondary consideration. As the trend in dentistry shifts towards fiber-reinforced composite endodontic posts and away from metal posts, this article reviews how fiber posts differ from their metal predecessors and how they vary intrinsically from one design and composition to another. Additionally, the article examines how fiber posts actually function and interact with the tooth.

Comparison of the passivity between cast alloy and laser-welded titanium overdenture bars.

Purpose: The purpose of this study was to investigate the fit of cast alloy overdenture and laser-welded titanium-alloy bars by measuring induced strain upon tightening of the bars on a master cast as well as a function of screw tightening sequence.

Materials And Methods: Four implant analogs were secured into Type IV dental stone to simulate a mandibular edentulous patient cast, and two groups of four overdenture bars were fabricated. Group I was four cast alloy bars and Group II was four laser-welded titanium bars.

Validation of strain gauges as a method of measuring precision of fit of implant bars.

Unlabelled: Multiple articles in the literature have used strain gauges to estimate the precision of fit of implant bars. However, the accuracy of these measurements has not been fully documented. The purpose of this study was to evaluate the response of strain gauges to known amounts of misfit in an implant bar.

The effect of etching technique on the retention of adhesively cemented prefabricated dowels.

Purpose: To determine if etching technique influences the bond strength of resin cement to root canal dentin.

Materials And Methods: Fifty-five extracted teeth were endodontically treated, dowel space prepared, and divided into five groups. Each group was treated with different etchant consistencies: acid gel, semi-gel, low-viscosity gel, liquid, and a self-etching primer.

Hardness and wear resistance of two resin composites cured with equivalent radiant exposure from a low irradiance LED and QTH light-curing units.

Purpose: To measure and compare three-body wear and Vickers hardness at depths of 0 mm and 2 mm in two composite resin materials cured with either a low irradiance light emitting diode (LED) or a quartz tungsten halogen (QTH) light-curing unit (LCU) in which exposure duration with the LED was increased to deliver equivalent radiant exposure in the 450-490 nm wavelength range.

Methods: The VIP QTH and Freelight LED LCU's were obtained and the emission spectrum of each was determined using a Spectra Pro 750 spectrograph. Irradiance in the 450-490 nm range for each LCU was determined by calculating the area under the spectral curve.