An Evaluation of Lubricants for Dental Handpieces and Contra-Angles

SINCE the advent of increased speeds of operation for the shaping of cavities, the problems associated with the care and maintenance of dental handpieces have become more significant.'4' 21 One of the most important is proper lubrication. The suggested materials and methods for the lubrication of handpieces and contra-angles are numerous and apparently many have been chosen rather empirically. Proper care of the dental handpiece and contra-angle involves (1) cleaning, (2) sterilization, (3) lubrication, and (4) adjustment. It seems, therefore, that an evaluation of the lubricating properties of a representative group of lubricants would be the first order of investigation into the general problem of care and maintenance of these instruments. The methods of cleaning and sterilization are, at least to sonme extent, dependent on the type of lubricant used, while the mechanical adjustment of the handpiece is common with, but independent of, these factors. The literature contains numerous references, but little information of value on the lubrication of dental handpieces and contra-angles, and only an empirical evaluation of the methods described.3-6 8,10,11,14,17,19, 20 Except for one of these articles,14 the lubrication described is accomplished during some form of hot fluid sterilization. Various cleaners or solvents are mentioned,6' 10, 19, 20 but no basis for their selection is reported. In this study, investigations of lubricating fluids were made in 4 areas: (1) viscosity, (2) stability of the fluids under heat, (3) practical evaluation in the straight handpiece, and (4) practical evaluation in the contra-angle.