PubMed · 16244422
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
David Hegarty, Ian O'Leary. 2005. Quick setup for light-cured bonding.. https://pubmed.ncbi.nlm.nih.gov/16244422/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
OBJECTIVE: To ascertain the efficacy of polymerization of self-etching dental adhesives in different solvent evaporation conditions. MATERIAL AND METHODS: Four self-etching adhesive systems were studied. Two of them are classified as mild two-step self-etching adhesives (Clearfil SE Bond, Protect Bond) and the other two are strong one-step systems (Xeno III, ADP-Prompt-L-Pop). The influence of temperature and duration of the air-drying period on photo-polymerization was followed by: gravimetry, (1)H solid-state NMR spectroscopy and stray-field MRI. The evolution of proton magnetization with irradiation time was recorded and correlated with volumetric polymerization shrinkage and extent of reaction; evaporation and hardening effects were identified. RESULTS: Main variables determining water-solvent evaporation of the tested adhesives are: (1) water/HEMA relative concentration, (2) presence of photoinitiator compounds in the primer (SEB) and (3) presence of ethanol (XENO). SEB shows the highest extent of photo-polymerization of the tested adhesives. The lowest volumetric contraction was obtained for APLP and XENO and the attempt to remove the solvents did not increase the extent of polymerization significantly. CONCLUSIONS: Temperature increase following photo-polymerization reaction is dominant towards the effect of the drying step for solvent evaporation in self-etching systems. Attempts to remove the solvents did not increase the extent of polymerization, so other problems are impairing the polymerization of one-step adhesives. CLINICAL SIGNIFICANCE: The use of tested one-step adhesives is discouraged as the attained low extent of polymerization may lead to low bond strength, high susceptibility to degradation and also will favor a continuing etching effect on the underlying dentin.
Resilon broadens the dimensions of endodontic adhesion by introducing the possibility of creating monoblocs between root canal filling materials and intraradicular dentin by using methacrylate-based sealers. The adhesive strength of Resilon to RealSeal, a methacrylate-based root canal sealer, was evaluated using a modified microshear bond testing design. Flat Resilon surfaces with different roughness were created for bonding to the sealer and compared to a composite control. The composite control exhibited mean shear strength 7.3 to 26.9 times higher than those of the Resilon groups. Shear strength differences among the Resilon groups of different surface roughness highlighted the contribution of micromechanical versus chemical coupling in sealer retention. Ultrastructural evidence of phase separation of polymeric components in Resilon suggested that the amount of dimethacrylate incorporated into this filled, thermoplastic composite may not yet be optimized for effective chemical coupling to methacrylate-based sealers.
The purpose of this study was to test the hypothesis that porcelain surface finishing, ie, low- and high-fusing porcelain, has an effect on the amount of force required to debond orthodontic brackets. A total of 20 high-fusing and 20 low-fusing porcelain specimens were prepared, polished, and bonded with standard edgewise brackets using a suggested porcelain bonding protocol. The brackets were debonded with a universal testing machine at shear mode. Resin removal was performed using two methods: a multifluted carbide bur with and without the use of Sof-Lex polishing discs. Representative specimens were studied under a scanning electron microscope before and after debonding to assess the surface morphology and potential surface damage. Statistical analysis with a t-test revealed that there was no difference between the two porcelain treatments on the force to debond values and no qualitative differences were observed on the porcelain surface between the two resin clean-up methods. From a clinical perspective, the practitioner can bond ceramic restorations without previous knowledge of the porcelain type used.