Dielectric spectroscopy of Anaerobic Adhesive cure

Abstract Dielectric spectroscopy (DS) is shown to be a most useful tool for the study of the surface initiated redox cure in model Anaerobic acrylic Adhesives. These models are deliberately designed to exhibit different levels of cure heterogeneity. The cure is initiated by the surfaces of two substrates on either side of a bondline. The heterogeneous cure situation is referred to as low cure through volume (CTV). Poor CTV is an undesirable feature that leads to mechanical weakness in an Adhesive bond. Thus, experimental techniques based on DS are developed to investigate the cure characteristics and in particular the CTV phenomenon in the model Anaerobic Adhesives.

Characterization of model Anaerobic Adhesive cure using real‐time fourier transform infrared spectroscopy and dielectric spectroscopy

A technique has been developed based on Fourier transform infrared spectroscopy (FTIR) in the attenuated total reflectance (ATR) mode, which is suitable for the investigation of the heterogeneous cure of surface-initiated redox polymerizations in thin and thick bondline situations. The results of the investigations into the surface-catalyzed and Anaerobically promoted cure of some model Adhesives using this method are reported. The systems under investigation were designed to exhibit different levels of cure heterogeneity or “cure through volume” (CTV) so that the influence of the bondline thickness and the formulation variables may be assessed. The analysis of the data provides evidence that supports our concept of the heterogeneous cure distribution existing in the form of a cure gradient. This concept of a cure gradient is developed further using dielectric spectroscopy. Here the cure gradient is characterized in terms of the parameters obtained using an empirical equation to fit the dielectric relaxation data. The results obtained using the infrared and dielectric spectroscopic methods are in satisfactory agreement and are shown to be most informative in characterizing and quantifying the CTV performance of the model Anaerobic Adhesives. © 1994 John Wiley & Sons, Inc.

characterization of model Anaerobic Adhesive cure using real time fourier transform infrared spectroscopy and dielectric spectroscopy

A technique has been developed based on Fourier transform infrared spectroscopy (FTIR) in the attenuated total reflectance (ATR) mode, which is suitable for the investigation of the heterogeneous cure of surface-initiated redox polymerizations in thin and thick bondline situations. The results of the investigations into the surface-catalyzed and Anaerobically promoted cure of some model Adhesives using this method are reported. The systems under investigation were designed to exhibit different levels of cure heterogeneity or “cure through volume” (CTV) so that the influence of the bondline thickness and the formulation variables may be assessed. The analysis of the data provides evidence that supports our concept of the heterogeneous cure distribution existing in the form of a cure gradient. This concept of a cure gradient is developed further using dielectric spectroscopy. Here the cure gradient is characterized in terms of the parameters obtained using an empirical equation to fit the dielectric relaxation data. The results obtained using the infrared and dielectric spectroscopic methods are in satisfactory agreement and are shown to be most informative in characterizing and quantifying the CTV performance of the model Anaerobic Adhesives. © 1994 John Wiley & Sons, Inc.

An investigation into the use of an Anaerobic Adhesive with two commercially available orthodontic brackets.

Summary Objectives The two objectives of this experiment were to determine the surface temperature of enamel following acid etching, rinsing and drying, and to see whether two commercially available orthodontic brackets could be bonded to enamel using an Anaerobic Adhesive. Methods Enamel surface temperature was determined in vivo using a surface temperature probe on a total of 60 patients. Stainless steel orthodontic brackets were bonded to human enamel using an Anaerobic Adhesive and a control orthodontic Adhesive. The enamel was etched prior to bonding either with a solution of 37% o-phosphoric acid or, in the case of the Anaerobic Adhesive specimens, with a solution of 37% o-phosphoric acid containing copper (II) chloride. After bench curing the specimens were shear bond tested to failure and the load at debond recorded in each case. Results The bond test results were analyzed using median force to debond (N) and 95% confidence intervals, Kaplan–Meier survival probabilities and log-rank tests. Conclusions After etching rinsing and drying the enamel surface temperature ranged from 21.54 to 24.19 °C, which is within the range suitable for Anaerobic Adhesive use. Bond testing to failure demonstrated that bracket base design affected the measured force to debond with both the Anaerobic Adhesive under test and the control Adhesive. In addition, the Anaerobic Adhesive was affected by the material composition of the bracket base and curing time. After 1 h of curing and using the Miniature Twin bracket, the measured force to debond exceeded the 10 min force to debond results of the control Adhesive. Significance It is possible to bond commercially available orthodontic brackets to teeth using an Anaerobic Adhesive.

Surfactants as part of a combined etchant and activator solution prior to the use of an Anaerobic Adhesive.

Abstract Objectives. The objectives of this experiment were to determine whether the incorporation of a surfactant into a combined etchant and activator solution would further promote the polymerization of an Anaerobic Adhesive. Method. Stainless steel attachments were bonded to human enamel using an Anaerobic Adhesive. In each case the enamel was etched and activated using a solution of 37% o-phosphoric acid containing copper (II) sulphates or chlorides with one of three surfactants also within the solution. After bench curing, the specimens were shear bond tested to failure and the load at debond recorded in each case. Results. The results were analysed using Kaplan–Meier survival probabilities and log-rank tests along with a multiple comparison test, using Bonferroni’s method. Conclusions. Under the conditions of this experiment the addition of a surfactant to a combined etchant activator solution of 37% o-phosphoric acid and either copper (II) sulphate or copper (II) chloride, prior to the use of an Anaerobic Adhesive can have a significant effect on measured force to debond. However, with copper (II) sulphate the highest force to debond was observed with the control solution without a surfactant. With copper (II) chloride the surfactant Tween 20 increased the observed force to debond but the effect was not statistically significant. Significance. Although it is possible to render the enamel surface both retentive and active towards Anaerobic Adhesives using a combined etchant and activator solution, the addition of a surfactant has little or no beneficial effect.

Phosphoric acid and various transition metal salt solutions as a combined etchant and activator prior to the use of an Anaerobic Adhesive.

Objectives. The objectives of this experiment were to determine whether various transition metal salts in 37% o-phosphoric acid could both activate and etch an enamel surface prior to the use of an Anaerobic Adhesive.

Method. Stainless steel attachments were bonded to human enamel using an Anaerobic Adhesive. In each case, the enamel was etched and activated using a solution of 37% o-phosphoric acid containing various transition metal sulfates and chlorides. After bench curing, the specimens were shear bond tested to failure and the load at debond recorded in each case.

Results. The results were analyzed using mean force to debond (N) and 95% confidence intervals. Kaplan–Meier survival probabilities and log-rank tests were also performed.

Conclusions. Under the conditions of this experiment, the sulfate and chloride of copper in acid were the most effective etching/activating solutions. There was no significant difference in the mean force to debond between the copper (II) sulfate and copper (II) chloride. The chloride in acid was, however, the only one of the two to produce a conventional etch pattern on the surface of the enamel.

Significance. It is possible to render the enamel surface both retentive and active towards Anaerobic Adhesives, such that relatively unreactive substrates can be bonded to enamel using such Adhesives.

Dielectric spectroscopy of Anaerobic Adhesive cure

Abstract Dielectric spectroscopy (DS) is shown to be a most useful tool for the study of the surface initiated redox cure in model Anaerobic acrylic Adhesives. These models are deliberately designed to exhibit different levels of cure heterogeneity. The cure is initiated by the surfaces of two substrates on either side of a bondline. The heterogeneous cure situation is referred to as low cure through volume (CTV). Poor CTV is an undesirable feature that leads to mechanical weakness in an Adhesive bond. Thus, experimental techniques based on DS are developed to investigate the cure characteristics and in particular the CTV phenomenon in the model Anaerobic Adhesives.

Characterization of model Anaerobic Adhesive cure using real‐time fourier transform infrared spectroscopy and dielectric spectroscopy

A technique has been developed based on Fourier transform infrared spectroscopy (FTIR) in the attenuated total reflectance (ATR) mode, which is suitable for the investigation of the heterogeneous cure of surface-initiated redox polymerizations in thin and thick bondline situations. The results of the investigations into the surface-catalyzed and Anaerobically promoted cure of some model Adhesives using this method are reported. The systems under investigation were designed to exhibit different levels of cure heterogeneity or “cure through volume” (CTV) so that the influence of the bondline thickness and the formulation variables may be assessed. The analysis of the data provides evidence that supports our concept of the heterogeneous cure distribution existing in the form of a cure gradient. This concept of a cure gradient is developed further using dielectric spectroscopy. Here the cure gradient is characterized in terms of the parameters obtained using an empirical equation to fit the dielectric relaxation data. The results obtained using the infrared and dielectric spectroscopic methods are in satisfactory agreement and are shown to be most informative in characterizing and quantifying the CTV performance of the model Anaerobic Adhesives. © 1994 John Wiley & Sons, Inc.

characterization of model Anaerobic Adhesive cure using real time fourier transform infrared spectroscopy and dielectric spectroscopy

A technique has been developed based on Fourier transform infrared spectroscopy (FTIR) in the attenuated total reflectance (ATR) mode, which is suitable for the investigation of the heterogeneous cure of surface-initiated redox polymerizations in thin and thick bondline situations. The results of the investigations into the surface-catalyzed and Anaerobically promoted cure of some model Adhesives using this method are reported. The systems under investigation were designed to exhibit different levels of cure heterogeneity or “cure through volume” (CTV) so that the influence of the bondline thickness and the formulation variables may be assessed. The analysis of the data provides evidence that supports our concept of the heterogeneous cure distribution existing in the form of a cure gradient. This concept of a cure gradient is developed further using dielectric spectroscopy. Here the cure gradient is characterized in terms of the parameters obtained using an empirical equation to fit the dielectric relaxation data. The results obtained using the infrared and dielectric spectroscopic methods are in satisfactory agreement and are shown to be most informative in characterizing and quantifying the CTV performance of the model Anaerobic Adhesives. © 1994 John Wiley & Sons, Inc.