Effect of fluoride application on shear bond strength of brackets bonded with a resin-modified glass-ionomer

PURPOSE: The purpose of this study was to assess the effect of fluoride application at 3 different steps of the bonding process on the shear bond strength and bond failure site of a resin-modified glass ionomer cement. MATERIAL: Sixty stainless steel brackets were bonded to bovine incisors with Fuji Ortho LC (GC Europe, Leuven, Belgium) under 4 different enamel conditions: (1) uncontaminated enamel, (2) enamel precleaned with fluoride-containing prophylaxis paste, (3) 1.1% acidulated phosphate fluoride (APF) gel applied immediately before conditioning, and (4) 1.1% APF gel applied immediately before bonding. After bonding, all samples were stored in distilled water for 24 hours and subsequently tested in shear mode on a universal testing machine. RESULTS: No significant differences were found between groups 1 (uncontaminated enamel) and 2 (fluoride application during prophylaxis). Both groups showed significantly greater shear bond strength values than groups 3 (fluoride application before conditioning) and 4 (fluoride application before bonding). Groups 3 and 4 did not differ significantly. Moreover, no significant differences in debond locations were found among the 4 groups. CONCLUSIONS: Fluoride application during initial prophylaxis does not affect the bond strength values of Fuji Ortho LC, whereas it significantly lowers bond strength values when applied before both conditioning and bonding

Effects of blood contamination on the shear bond strengths of conventional and hydrophilic primers

The purpose of this study was to assess the effect of blood contamination on the shear bond strength and failure site of 2 orthodontic primers (Transbond XT and Transbond MIP; 3M/Unitek, Monrovia, Calif) when used with adhesive-precoated brackets (APC II brackets; 3M/Unitek). One hundred twenty bovine permanent mandibular incisors were randomly divided into 8 groups; each group contained 15 specimens. Each primer-adhesive combination was tested under a different enamel surface condition: dry, blood contamination before priming, blood contamination after priming, or blood contamination before and after priming. Stainless steel APC II brackets were bonded to the teeth. After bonding, all samples were stored in distilled water at room temperature for 24 hours and subsequently tested for shear bond strength. Noncontaminated enamel surfaces had the highest bond strengths for both conventional and hydrophilic primers; their values were almost the same. Under blood-contaminated conditions, both primers showed significantly lower shear bond strengths. For each type of primer, no significant differences were reported among the blood-contaminated groups. Significant differences in debond locations were found among the groups bonded with the 2 primers under the various enamel surface conditions. Blood contamination of enamel during the bonding procedure of conventional and hydrophilic primers significantly lowers their bond strength values and might produce a bond strength that is not clinically adequate

Les attaches orthodontiques en céramique : – analyse morphostructurale au microscope électronique ; – forces d'arrachement in vitro ; – recyclage thermo-ultrasonique

Après avoir considéré les propriétés chimiques, mécaniques et optiques des attaches en céramique, les méthodes de collage et de dépose, les indications et les contre-indications de ces attaches, les auteurs étudient leurs caractéristiques morphostructurales par l'analyse au microscope électronique. L'adhésif photopolymérisant est pour certains auteurs la méthode de choix pour les attaches en céramique. Ils proposent en outre deux protocoles de recyclage

Correcting a single-tooth anterior crossbite with lingual segmented mechanics

Some clinicians use glass ionomer splints to free the anterior teeth in cases of deep over­bites. This article demonstrates the combined use of a lingual cantilever and a glass ionomer splint for correcting a single-tooth anterior cross­bite

Lampada alogena e al plasma in ortodonzia: un confronto in vitro

Adesivi per ortodonzia e polimerizzazion

One-appointment correction of a scissor bite with 2D lingual brackets and fiber-reinforced composites

This article describes a quick and simple method to correct a scissor bite using 2D lingual brackets, a nickel titanium wire segment, and fiber-reinforced composites (FRCs) for anchorage reinforcement