HOW WELL ARE COMPLETE DENTURES COPIED

Objective To assess how accurately the same set of complete dentures c ould be copied by 12 different laboratories. Design A prospective stud y. Settings Completed by commercial laboratories used by GDPs in Engla nd (1996). Results were analysed and controlled by a university depart ment. S ubjects (materials) and methods The master set was constructed to include a midline diastema and a bilateral posterior crossbite. Tw elve sets of silicone moulds of the master denture were prepared. GDPs selected commercial laboratories of their choice to receive the work. Main outcome measures All stages of the work were compared with the m aster dentures by returning them to a specially adapted articulator. A nalysis was completed using preset criteria. Results Only five of the returned copies were considered to have both good quality acrylic resi n work and clear details of the teeth in wax. Only four cases reproduc ed the diastema. After processing, the occlusal vertical dimension had been increased in eight of the cases and the bilateral crossbite had been eliminated in all cases. Conclusions None of the final copy dentu res were considered an accurate copy of the master dentures. There is considerable scope for further training of dental technicians in this important technique.