A COMPARISON OF STEREOLOGICAL AND COMPUTER-ASSISTED HISTOMORPHOMETRICANALYSIS AS TOOLS FOR HISTOLOGICAL QUANTIFICATION IN REGENERATIVE STUDIES

This study was designed to compare computer-assisted histomorphometric analysis (CAHA) and stereology (STER) as measurement tools for evalua ting the repair response during periodontal wound healing. Thirty-six histological sections derived from 4 surgically created defects in the furcation of mandibular second premolars of sheep were measured by ea ch technique to determine the furcation area and volume, and the perce ntage of new bone formation at 7 wk postoperatively. Slides were viewe d in random order with the source unknown to the examiner (JL). One se ction from each of the 4 specimens was flagged for triplicate measurem ent by each technique. Intra-examiner error was determined to be low a s the coefficient of variation in each of the 2 techniques was between 1% and 4%. A consistently higher percentage of bone was identified us ing stereology. The coefficient of agreement was plotted to determine how closely these 2 techniques were matched in their respective estima tions of bone hh in a furcation defect. This analysis revealed statist ical bias between the 2 techniques and a low degree of agreement betwe en them. This study demonstrates that the 2 techniques are not interch angeable. It also emphasizes that the reader must be cautious when com paring results from studies in which different systems of measurement and analysis have been used. Stereology was determined to be the measu rement tool of choice due to its high degree of reproducibility, ease of use and efficient use of time.