Comparison between bond strength of lithium disilicate with preheated composite, flowable composite and resin cement

Abstract

Objective: investigation of the microshear bond strength between lithium disilicate with preheated viscous composite, flowable composite and resin cement by comparison of their microshear bond strength.Material and method: forty-five samples were prepared and divided into three groups; preheated viscous composite, flowable composite and resin cement. Materials were injected into plastic transparent molds (2 mm height, 2 mm diameter) on the surface of lithium disilicate discs previously surface treated with ceramic etchant (hydrofluoric acid 4.5%) and ceramic primer (silane coupling agent). Microshear bond strength test was performed samples by universal testing machine.Results: highest microshear bond strength was recorded for preheated viscous composite.Conclusions: preheated viscous composite is an excellent material in cementation of lithium disilicate ceramic restorations.

Preheating of dental composite resins: A scoping review

“…25 Two studies analyzing bond strength to lithium disilicate reported similar values when preheated CR, resin cement and flowable CR were compared. 30,51 Seven out of nine studies showed high conversion degree after preheating the CR, 13,15,28,34,[46][47][48] but two studies showed that preheating did not increase the conversion degree. 23,34 In most studies, increased temperature also increased microhardness of CR.…”

“…Of six studies that assessed bond strength using preheated CR, four analyzed bonding to dentin, 22,25,38,50 and two the bonding to lithium disilicate ceramics 30,51 . In two studies, preheated CR showed higher bond strength to dentin than unheated CR, 38,50 only one study did not report significant differences 22 .…”

“…In addition, higher bond strength was reported between resin cement and indirect restoration than between heated CR and indirect restoration 25 . Two studies analyzing bond strength to lithium disilicate reported similar values when preheated CR, resin cement and flowable CR were compared 30,51 …”

“…Most studies showed that increased flowability improved marginal adaptation due to better contact with the substrate surface 23–25,27,29,37,42,43,55 . Less viscosity after preheating may also enhance the penetration of CR in micro‐retentive areas of the substrate, improving adhesion between CR, enamel, dentin, and restorative material 50,58 and bonding of indirect restorations 25,30,51 . However, a rapid reduction in temperature when the CR is removed from the heating device can immediately increase viscosity 54 .…”

“…[23][24][25]27,29,37,42,43,55 Less viscosity after preheating may also enhance the penetration of CR in micro-retentive areas of the substrate, improving adhesion between CR, enamel, dentin, and restorative material 50,58 and bonding of indirect restorations. 25,30,51 However, a rapid reduction in temperature when the CR is removed from the heating device can immediately increase viscosity. 54 A study showed that clinicians have between 10 and 15 s of working time with preheated CR before significant changes in temperature and viscosity occur.…”