There is a range of treatment options for the management of the pulp in extensively decayed teeth. These include direct and indirect pulp capping, pulpotomy or pulpectomy. If the tooth is symptomatic or if there are periapical bone changes, then endodontic treatment is required. However, if the tooth is asymptomatic but the caries is extensive, there is no consensus as to the best method of management. In addition, there has been a recent move towards using alternative materials and methods such as the direct or indirect placement of bonding agents and mineral trioxide aggregate.Most studies have investigated the management of asymptomatic carious teeth with or without an exposed dental pulp using various capping materials (e.g. calcium hydroxide, Ledermix, Triodent, Biorex, etc.). However, there is no long term data regarding the outcome of management of asymptomatic, carious teeth according to different regimens. This study aims to assess the effectiveness of techniques used to treat asymptomatic carious teeth and maintain pulp vitality. Electronic searches of the following databases were undertaken: The Cochrane Oral Health Group's Trials Register (March 2006), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2006, Issue 1), MEDLINE (1966 to week 4, February 2006), EMBASE (1974 to 13 March 2006), National Research Register (March 2006), Science Citation Index - SCISEARCH (1981 to March 2006). Detailed search strategies were developed for each database. Handsearching and screening of reference lists were undertaken. There was no restriction with regard to language of publication. Studies included were randomised controlled trials (RCTs). Asymptomatic vital permanent teeth with extensive caries were included. Studies were those which compared techniques to maintain pulp vitality. Outcome measures included clinical success and adverse events. Data were independently extracted by three review authors. Authors were contacted for details of randomisation and withdrawals and a quality assessment was carried out. The Cochrane Collaboration's statistical guidelines were followed. Only four RCTs were identified. Interventions examined included: Ledermix, glycerrhetinic acid/antibiotic mix, zinc oxide eugenol, calcium hydroxide, Cavitec, Life, Dycal, potassium nitrate, dimethyl isosorbide, and polycarboxylate cement. Only one study showed a statistically significant finding; potassium nitrate/dimethyl isosorbide/polycarboxylate cement resulted in fewer clinical symptoms than potassium nitrate/polycarboxylate cement or polycarboxylate cement alone when used as a capping material for carious pulps. It was disappointing that there were so few studies which could be considered as being suitable for inclusion in this review. The findings from this review do not suggest that there should be any significant change from accepted conventional practice procedures when the pulp of the carious tooth is considered. Further well designed RCTs are needed to investigate the potential of contemporary materials which may be suitable when used in the management of carious teeth. It is recognised that it is difficult to establish the 'ideal' clinical study when ethical approval for new materials must be sought and strict attention to case selection, study protocol and interpretation of data is considered. It is also not easy to recruit sufficient numbers of patients meeting the necessary criteria.