A histological and quantitative histomorphometric study of apexification of nonvital permanent incisors of vervet monkeys after repeated root filling with a calcium hydroxide paste

Abstract

The purpose of this study was to compare the effect of a monthly refilling of the root canals with calcium hydroxide paste with a single packing or replacement of the paste at 3 months on the apexification of nonvital maxillary incisors of vervet monkeys. Forty-eight maxillary incisors from 12 monkeys were used following radiographic determination that root development was incomplete. The pulps were extirpated under general anesthesia and the root canals filed and cleaned. The root canals were filled with a commercial calcium hydroxide paste, Calxyl, and a temporary cavity filling placed. Twelve teeth were left without further treatment. The calcium hydroxide paste was replaced in 12 teeth after a 3-month interval, and in the remaining 24 teeth the calcium hydroxide root filling was replaced five times at monthly intervals. The monkeys were killed after 6 months, and blocks of the teeth and surrounding tissues were embedded, decalcified and 6 microns serial sections prepared and stained. The sections were studied histologically to evaluate 11 parameters. Significant differences were found in the amount of calcium hydroxide at the apices, the presence of new cementum on the roots and the degree of inflammation, all of which were better in the monthly refill group. Histomorphometric measurements to evaluate the obturation of the open apices and the volume of new primary osteocementum showed no significant difference between the three groups. It was suggested that after the initial root filling with calcium hydroxide there was nothing to be gained by repeated root filling either monthly or after 3 months, for at least 6 months.

Suggesting a new therapeutic protocol for permanent teeth with incomplete root apex and lateral luxation: A case report

“…Due to wide apical foramen diameter and the presence of exudate in the periapical region, dressing dissolution rate increases, thereby creating the need for change. 21,22 The present study agrees with the following authors when suggesting to keep intracanal dressing inside the root canal for much longer periods without periodic changes: Chosack et al, 23 Felippe et al, 28 Steiner et al, 29 Chawla et al 33 and Túrkún. 36 The study conducted by Chawla 33 found mineralized tissue formation after intracanal dressing remained in the root canal for 6 to 12 months without periodic changes.…”

Successful closure of the root apex in non-vital permanent incisors with wide open apices using single calcium hydroxide (caoh) dressing - report of 2 cases

“…Chawla (6) has suggested that the amount of CaOH in the single root canal dressing was sufficient to initiate and complete the bridge in 92.3% of the teeth in his study. Chosack et al (12) suggested that repeated root filling are not required as CaOH is only required to initiate healing process. They also reported that the CaOH has to be replaced if there are any symptoms or displacement of the medicament.…”

Treatment Options: Apexogenesis and Apexification

“…The suggested time to change the CH in the canal varies from once every 3 months, once every 6-8 months, or not at all (31)(32)(33).…”