HISTOLOGICAL TECHNIQUES TO IMPROVE TESTING OF PULPAL RESPONSE OF TEETH TO FILLING MATERIAL

Two fixation fluids, two fixation techniques and two embedding methods were investigated for their effects on the quality of sections of tee th for pulpal response to filling materials to improve evaluation of p ulpal responses. Sections from 32 baboon teeth were prepared, half wit h experimental cavities and half without, using either 10% formaldehyd e or 4% glutaraldehyde, longitudinal tooth splitting or removal of the tooth apex, and paraffin or K plast resin embedding; decalcification in a formic acid mixture was a constant throughout. Histometric analys is showed that paraffin embedding produced less shrinkage than the K P last resin embedding although the difference was not statistically sig nificant. Six parameters of separation at the pulp:dentine interface w ere studied: embedding, fixative, presence or absence of a cavity, cut ting technique and individual animal tooth type. Statistical investiga tion revealed that fixative, cutting technique, and fixative and cutti ng technique combined had significant influences on the separation art ifact. Of the combinations tested the choice of embedding method depen ds on which of the two artifacts, shrinkage or separation, is more adv erse in the opinion of the investigator. Four percent glutaraldehyde t ogether with the longitudinal split technique of fixation, processed b y either K Plast resin embedding or paraffin embedding produced satisf actory pulpal sections.