are commonly used because of their low tensile strength and lack of adhesion which provides ease of removal. These products should not be used when resin composite is to be planned for bonding the definitive crown as eugenol is able to infiltrate and diffuse through dentine; contaminating tooth surface and compromising bonding by inhibiting polymerisation of resin. Commercially available products include RelyX Temp E (3M ESPE), Temp-Bond (Kerr) and Flow Temp (Premier Dental Products). Non-eugenol temporary luting cements Non-eugenol cements replace eugenol with several types of carboxylic acids which do not inhibit definitive cementation. These cements are compatible with temporary resin materials and definitive resin cements and have increased retention when compared to ZOE containing cements. Examples of commercially available products include RelyX Temp NE (3M ESPE) and Temp-Bond NE (Kerr). Polycarboxylate temporary luting cements This hydrophilic cement has the benefit of minimal effects on temporary resin containing agents and weak adhesion to tooth tissue which increases ease of removal. This cement is the easiest to clean out of all the provisional cement types. Examples include Ultradent and Hy-Bond (Shofu Dental). Resin temporary luting cements The advantages of these cements include superior aesthetics, greater strength, superb retention and ease of cleaning. However, amongst the drawbacks of this cement is the higher rate of discolouration, microleakage and odour experienced. Commercially available examples of temporary resins cements include Systemp.link (Ivoclar Vivadent), Temp-Bond Clear (Kerr) and ImProv (Nobel Biocare). Tooth preparation impressions Once the tooth in question has been prepared with acceptable dimensions, it is equally important to make an accurate and dimensionally stable record or impression of the preparation or dental implant, surrounding hard and soft tissues as well as the opposing dental arch so that the restoration created will conform to the required dimensions and ensure the fit is as close as possible without having to make many modifications chair-side. Impressions can be made digitally or by conventional technique. With regards to conventional impression techniques, the materials selected should have appropriate physical properties and handling characteristics to allow enough detail reproduction and durability when casting a model, including the ability to withstand effective decontamination procedures. Generally, impressions of the arch where the preparation is made are in addition silicone using the "wash impression" technique; impressions of the opposing arch are made in alginate. Digital impressions can be made using dedicated optical scanners. A review suggests that digital impressions provide the same