Activities Education - Following a pre-pilot project completed in April 1997, phase two began in July 1997 and was completed in July 1998. This:  helped to deliver tutorials as part of two existing postgraduate training programmes; developed and evaluated protocols for using videoconferencing to deliver postgraduate teaching.   Diagnosis: Begun in September 1998, phase three of the project was a two year programme to trial a three-tiered approach to providing remote treatment advice by teledentistry. This included: 1) An expert system developed by the project that filters out cases that can be treated locally by the GDP,   2)  A store and forward form of electronic referrals using electronic whiteboards containing text and images about the case and including output from the expert system.  Transmission is by FTP.   3) The use of video-conferencing to enable practitioner and specialist to discuss more complex cases.   The trial was carried out with six (and a seventh participating unofficially) dental practices based around England.