Role of Liners in Restorative Dentistry

Comparative Evaluation of Shear Bond Strength of Composite to Dentin in Presence of Calcium Releasing Liners: An In-Vitro Study

“…Moreover, they reported Lime-lite as the less soluble material in water and acetic acid, among others. However, less solubility of Light Cured Calcium Hydroxide liners in water due to resin-based structure [3,37] can justify better SBS results of lime-lite compared to Dycal; however, the difference was not significant.…”

“…The higher SBS of TheraCal may also be attributed to the hydrophilic resin-based methacrylate monomers of its structure that increase chemical adhesion to dentin and forms a strong interface between TheraCal and the bonding surface [32,33]. Furthermore, Theracal has shown lower solubility than Biodentine and calcium-hydroxide-based liners [3,34,35]; thus, it seems that the contamination of the dentine surface due to the etching process, which is supposed to have a role in the bonding of composite to dentin, is less likely to occur.…”

“…Protective dental liners are applied in deep cavities to protect the pulp from different stimuli and facilitate the formation of reparative dentine [1]. These materials can seal dentinal tubules and protect the pulp from microorganisms' attacks and also have therapeutic effects and irritants as well as thermomechanical stimuli [2].Various materials have been used as cavity liners, including Resin Modified Glass Ionomer Cement, calcium silicate-based liners, calcium hydroxide liners, and bioactive glass-based cement [1,3,4] Traditionally, calcium hydroxide has been considered the gold standard of cavity lining materials for several years, in the case of direct and indirect pulp capping treatment procedure due to excellent antibacterial properties, alkaline pH, and its bioactivity in terms of formation of hard tissue barrier [5]. However, the unfavorable effects of calcium hydroxide, such as the weak physical properties, tunnel defects, high solubility, and gradual dissolution, led to a decline in its use as a liner with time [6], to overcome these undesirable drawbacks, several other materials have been introduced, light-activated calcium hydroxide lining materials were one of them which provides improved physical properties, decreased solubility in acids and water, although their bond to the substrate is weak and can shrink during polymerization.…”

“…However, the unfavorable effects of calcium hydroxide, such as the weak physical properties, tunnel defects, high solubility, and gradual dissolution, led to a decline in its use as a liner with time [6], to overcome these undesirable drawbacks, several other materials have been introduced, light-activated calcium hydroxide lining materials were one of them which provides improved physical properties, decreased solubility in acids and water, although their bond to the substrate is weak and can shrink during polymerization. [ [3,7]]. Lime-Lite is a new resin-based light-activated calcium hydroxide-based material that could be applied as a liner and base [8], according to the manufacturer: this material contains hydroxyapatite (HA) and releases hydroxyl, fluoride, and calcium [9].…”

“…For deeper restorations that are near to the pulp, without the pulp exposure, an RMGIC is one of the best choices. These materials are dimensionally very stable, release fluoride, bond to dentin and composite [3,17]. Furthermore, the adaptation of RMGIC over some liners has been advised; for instance, in order to overcome the drawbacks of calcium hydroxide liners, a protective layer of RMGI base over this liner is recommended, especially in deeper cavities.…”