Chemomechanical removal of dental caries in deciduous teeth: Further studies in vitro

Objective: To further investigate the efficacy of N-monochloro-DL-2-aminobutyrate (NMAB) and NMAB containing 2M urea (NMAB-urea) as chemomechanical caries removal reagents in deciduous teeth using standardised lesions and limited applicator pressure. Design: In vitro. Method: Carious dentine was removed from standardised lesions in deciduous teeth using NMAB, NMAB-urea or isotonic saline (control); 50 lesions were studied with each reagent. The surface of the dentine remaining in cavities where complete caries removal was achieved was examined by light and scanning electron microscopy. Main results: NMAB-urea (but not NMAB) gave significantly improved caries removal compared with saline. The dentine surfaces remaining after complete caries removal were irregular and approximately one third were bacterially contaminated. Conclusions: The improved efficacy of NMAB by the addition of urea has been confirmed. Toxicity studies are still necessary prior to clinical use of this reagent. © British Dental Journal 1999.link_to_subscribed_fulltex

Nickel-titanium alloys: a systematic review

OBJECTIVE: A systematic review on nickel-titanium wires was performed. The strategy was focused on Entrez-PubMed-OLDMEDLINE, Scopus and BioMed Central from 1963 to 2008. METHODS: Papers in English and French describing the behavior of these wires and laboratorial methods to identify crystalline transformation were considered. A total of 29 papers were selected. RESULTS: Nickel-titanium wires show exceptional features in terms of elasticity and shape memory effects. However, clinical applications request a deeper knowledge of these properties in order to allow the professional to use them in a rational manner. In addition, the necessary information regarding each alloy often does not correspond to the information given by the manufacturer. Many alloys called "superelastic" do not present this effect; they just behave as less stiff alloys, with a larger springback if compared to the stainless steel wires. CONCLUSIONS: Laboratory tests are the only means to observe the real behavior of these materials, including temperature transition range (TTR) and applied tensions. However, it is also possible to determine in which TTR these alloys change the crystalline structure