Trauma to the teeth, gums and dental restorations during medical procedures can be avoided by the use of a mouth protector. Three types of material are discussed and the techniques for manufacture and use are described. Two of the types are available from the manufacturer as preformed U-shaped 'shells', while the third type was manufactured especially for this study on randomly selected maxillary models of different sizes. All three types of mouth protector proved to be successful over the limited period employed in this study. Minor adjustments can be made to some of the mouth protectors for better durability and comfort. More research is needed on many more patients before the effectiveness of the different types of mouth protector can be finally assessed.