Clinical Pilot Study of: Astringent Retraction Paste, Imprint™ 4 VPS, Imprint 4™ Preliminary, Intra-oral Syringes, 3M ESPE New Temporary Restoration (SuPro 100 and Temporary Cement), RelyX™ Unicem™ 2 Automix Cement, Lava™ Plus Zirconia Crowns

This clinical study seeks to address four independent questions that are all part of the delivery of care associated with the provision of a single item of treatment; an indirect restoration (known as a 'crown') to restore and cover a damaged tooth. The provision of a crown requires a series of sequential clinical and laboratory stages stages:

1. Stage 1 - Preliminary impression. Taking a pre-operative impression of the tooth to be crowned. This will be used to enable the fabrication of the temporary crown after the tooth has been prepared. This is standard care and follows established clinical protocols.
2. Stage 2 - Preparation of the tooth. This involves cutting the tooth back to make space for the crown that will be fabricated to replace the missing structure.
3. Stage 3 - Taking an impression of the prepared tooth. From this a duplicate model will be made to fabricate the crown. To take the impression, the dentist will need to gently push the gums away from the tooth by fractions of a millimeter so that the margins of the preparation are clearly discernible.
4. Stage 4 - Provision of a temporary restoration that will provide satisfactory function for a limited period of time, until the definitive crown can be fitted. This temporary crown is designed to have a finite short-term durability and have an ease of manufacture and subsequent removal; hence the use of a specific cement that will enable this.
5. Stage 5 - Fitting of the definitive restoration. This is designed to be a durable restoration, with a mean life expectancy measured in years, but which is ultimately determined by a number of clinical, biological and patient specific parameters. Definitive restorations are fitted with cement designed to retain the crown in permanent manner.