Effect of various irrigant and autoclaving regimes on the fracture resistance of rubber dam clamps

Abstract

Rubber dam clamps are known to break during clinical use in endodontics. This in-vitro study examined some of the variables which may contribute to the fracture. Stainless steel rubber dam clamps were subjected to various cleaning and autoclaving regimes and exposure to various solutions of sodium hypochlorite (NaOCl). Each clamp was examined after four cycles of cleaning and exposure to NaOCl. During environmental exposure to NaOCl, the clamp was stressed over a perspex rod to simulate placement onto the crown of a tooth. Clamps were examined after each test cycle visually and microscopically, or immediately after breakage. Results suggested that the fractures were because of a stress corrosion cracking phenomenon. There was evidence of intergranular and transgranular cracking of the metal. Corrosion spots were seen on the surface of the clamps and fracture occurred mainly through these spots. A number of recommendations to reduce breakage of clamps have been suggested.

Effect of Repeated Moist Heat Sterilization on Titanium Implant–Abutment Interface—An In Vitro Study

“…Sterilization does affect the mechanical properties of the implant surface, especially the one made of titanium. Sutton and Saunders 22 asserted that sterilization in the autoclave is responsible for alterations in the mechanical properties leading to plastic deformation in steel materials when submitted to high levels of stress. They also stated that, due to the lower rate of dissolution of the titanium oxide, this metal shows a passive state and is, therefore, less prone to corrosion.…”

Effect of repeated autoclave on hardness and tensile strength of polypropylene/natural rubber developed for rubber dam clamp

“…3. The NR phase is dispersed in the PP matrix as small droplets, and the NR phase both in terms of size and quantity slightly increases with increasing NR content.…”

“…[2] Despite their established bene ts, traditional stainless steel clamps have some drawbacks, such as trauma to gingival tissues, clamp slippage, poor peripheral sealing in severely worn teeth, corrosion, and limitations in bending resistance after multiple uses. [3,4] To address these challenges, exible (non-metallic) clamps like the SoftClamp™ by Kerr Corp., Orange, CA, have been proposed to reduce patient discomfort and iatrogenic damage. [5] However, the prohibitive cost of non-metallic clamps limits their widespread use.The study focuses on exploring a new alternative for developing reusable non-metallic clamps using polypropylene (PP) and natural rubber (NR) blends.…”

In vivo fracture of a new rubber-dam clamp

“…The thickness of the coating is approximately 6.5 mm and is applied in order to enhance corrosion resistance (Jedynakiewicz et al 1985). The second group is made of martensitic stainless steel 7C27Mo (13.5 Cr, 1.0 Mo, 0.38 C, 0.55 Mn, and 0.40 Si all in wt.%) of 525 Vickers hardness (Sutton & Saunders 1996). Alternatively, the type of 420 martensitic stainless steel with minor differences in composition (12-14 Cr, 0.15 C min., 1.0 Mn, 1.0 Si, 0.04 P and 0.03 S all in wt.%) (Davis 1993) is specified by a US government document (Medical Procurement Item Description 1983).…”