Connective Tissue Reaction to White and Gray MTA Mixed With Distilled Water or Chlorhexidine in Rats

INTRODUCTION The purpose of this study was to compare the histocompatibility of white (WMTA) and gray (GMTA) mineral trioxide aggregate mixed with 0.12% chlorhexidine (CHX) and distilled water (DW) in subcutaneous connective tissues of rats. MATERIALS AND METHODS The freshly mixed WMTA and GMTA with CHX or DW were inserted in polyethylene tubes and implanted into dorsal subcutaneous connective tissue of 50 Wistar Albino rats; tissue biopsies were collected and were then examined histologically 7, 15, 30, 60 and 90 days after the implantation procedure. The histology results were scored from 1-4; score 4 was considered as the worst finding. Data were analyzed using one-way ANOVA tests. RESULTS All experimented materials were tolerated well by the connective tissues after 90-day evaluation, except for the WMTA/CHX group that had significantly more mean inflammatory scores (P<0.001). There was a statistically significant difference in the mean inflammation grades between experimental groups in each interval (P<0.001). After 90 days, GMTA/CHX group had the lowest inflammatory score. CONCLUSION Although adding CHX to WMTA produces significantly higher inflammatory response, it seems a suitable substitute for DW in combination with GMTA. Further research is necessary to recommend this mixture for clinical use.