Tensile Bond Strength Between Fissure Sealants and Enamel

Abstract

Acrylic buttons were attached to tooth enamel by in situ curing of three types of polymeric fissure sealants, a dental cement, and a glass ionomer cement and then were immersed in water. The polymeric materials exhibited the greatest bond strengths to enamel, but in two instances the bond strength decreased with time although the cements showed increased strength. One polymeric material exhibited an unchanged bond strength.

Etching of enamel prior to application of fissure sealants

“…The forces required to separate the buttons from the enamel surfaces of the teeth for the polymeric materials Epoxylite 9075 and Nuva Seal after 4 h are given in Table 2 and (Williams et al, 1974). ns, F>0 05. of the materials and also compare bond strengths obtained using buffered acid (7 % zinc oxide) with the unbuffered acid etchants.…”

“…The experimental technique used has been described previously (Williams et al, 1974). Clear acrylic* buttons of surface area 12-57 mm^ were cemented to teeth.…”

“…After polymerisation the tooth/button combinations were stored in tap water at 37 ± 1 °C for 4h. The test method has been reported elsewhere (Williams et al, 1974) and involved pulling the buttons from the teeth at a cross head speed of 0-2 cm/ min using an Instron Universal testing machine. The mean bond strength and standard deviation were calculated for each fissure sealant.…”

A method of determining the tensile bond strength of fissure sealant materials

“…Table 1 shows the coefficient of variation and provisional classification of the complexity of the methods reported in the past. , Swartz & Phillips, 1955Lee et al, 1969,• •> Eden et al, 1970Otsuki et al, 1973Williams et al, 1974 Complexity The exact mechanism by which sealants applied to the teeth are lost under clinical conditions is not yet established, but clinical observation indicates that it is most probably an adhesive or adhesive/cohesive break at the enamel-sealant junction. This is supported by Retief (1974) who has shown that during tensile bond strength studies, spicules of adhesive remain embedded in the etched enamel surface whilst spicules of fractured enamel are retained within the interface on the adhesive side.…”

“…Numerous methods have been described previously for measuring the tensile bond strength of dental materials to enamel (Swartz & Phillips, 1955;Bowen, 1965;Lee, Swartz & Culp, 1969;Eden, Craig & Peyton, 1970;Otsuki et al, 1973;Williams, von Fraunhofer & Winter, 1974). The accuracy achieved in adhesion tests of sealant materials to natural teeth (human or bovine) are limited by variations in the microscopic structure and composition of the enamel.…”