TIMING OF CALCIUM HYDROXIDE THERAPY IN THE TREATMENT OF ROOT RESORPTION IN REPLANTED TEETH IN DOGS

The effect of time of the onset of calcium hydroxide (CH) pulpectomy o n root resorption of 31 permanent dog incisors was investigated. CH pu lpectomy was delayed 4, 9, 14 and 18 days after the teeth were extract ed and replanted. Control teeth were replanted 1) without pulpectomy, 2) with a pulpectomy only or 3) with a pulpectomy and CH filling. All teeth were prepared for histologic evaluation 8 weeks after the teeth were replanted. Cross section were examined using a computer microscop e and linear (mum) and/or square areas (mum2) of surface (SRR), inflam matory (IRR), and replacement (RRR) root resorption were calculated. F rom this data the percentage of linear and area resorption was average d for each group. Duncan multiple range t-test (P less-than-or-equal-t o 0.05) revealed that teeth in which a pulpectomy with CH filling was done extraorally had significantly greater SRR than the rest of the gr oups; teeth in which a pulpectomy without CH filling was done extraora lly had significantly greater RRR than teeth in which CH pulpectomy wa s delayed for 18 days; there was no significant difference in SRR, IRR or RRR when CH placement was delayed 4, 9, 14 or 18 days after replan tation. Although it was not significant the overall resorption was lea st when CH pulpectomy was delayed 18 days.