Lining Materials

thermal - protect pulp from temperature damage chemical - protect pulp from chemicals released from restoration bacteria - protect pulp from bacteria due to microleakage from restoration

therapeutic - put down to reduce inflammation of pulp, stops thermal conduction of restorative material, definitive restoration can be placed on top palliative - put down in reversible pulpitis, causes pulp to regress and tertiary dentine is formed, temp restoration placed over, can then go back and do definitive restoration

low thermal conduction - reduce heat transferred to pulp to prevent pulpal injury thermal expansion - should be similar to that of dentine and enamel, prevent micro leakage, 8 or 11 mechanical strength - needs to be high to withstand pressure of placing restorative material on top low solubility - if soluble, dentinal fluid will cause it to wash away

creates an environment with a pH of 12, bacteria requires an acidic environment, therefore, kills any bacteria remaining. also irritates the dentine, causing odontoblasts to produce tertiary dentine, results mineralised layer between pulp and restoration

low mechanical strength, and highly soluble, any microleakage can result in the lining disappearing

zinc oxide and phosphoric acid, acid base reaction followed by a hydration reaction

has an initial low pH, can cause pulpal irritation, also an exothermic reaction and heat damages the pulp, doesnt bind to the tooth tissue, micro leakage is possible

both use zinc oxide but different acids

bonds to tooth in similar way to GIC, less heat released, has a low initial pH but returns to normal much faster

lower mechanical strength than zinc phosphate, high solubility, opaque

chelation reaction between zinc oxide and eugenol, produces zinc eugenolate mix, integrates unreacted zinc oxide into material

low thermal conduction, soluble - bad as break down material but good as eugenol is released which calms down the pulp, low mechanical strength - cant be used under amalgam as wouldnt withstand packing

prevents the resin from setting

addition of resin, doesnt interact with setting reaction just increases mechanical strength

ethoxybenzoic acid, quartz and alumina

increases mechanical strength by encorporating crystalline structure, reduces solubility

command set, thermal expansion similar to tooth, low thermal conductivity, binds well to tooth tissue and can then bond to composite resin, good marginal seal, has very high mechanical strength, much higher than any other liner, can be cariostatic and release fluoride

when the cavity approaches the pulp or a pulpotomy, direct or indirect pulp cap

all amalgam fillings and a large composite filling, also for crown prep or placing indirect restorations