Delayed tooth replantation after root surface treatment with sodium hypochlorite and sodium fluoride: histomorphometric analysis in rats

Abstract

In cases of delayed tooth replantation, non-vital periodontal ligament remnants have been removed with sodium hypochlorite in an attempt to control root resorption. Nevertheless, reports of its irritating potential in contact with the alveolar connective tissue have been described. Therefore, this study evaluated the healing process on delayed replantation of rat teeth, after periodontal ligament removal by different treatment modalities. Twenty-four rats, assigned to 3 groups (n=8), had their upper right incisor extracted and left on the workbench for desiccation during 60 min. Afterwards, the teeth in group I were immersed in saline for 2 min. In group II, root surfaces were scrubbed with gauze soaked in saline for 2 min; and in group III, scrubbing was done with gauze soaked in 1% sodium hypochlorite solution. Thereafter, root surfaces were etched with 37% phosphoric acid and immersed in 2% acidulate-phosphate sodium fluoride solution, at pH 5.5. Root canals were filled with a calcium hydroxide-based paste and the teeth were replanted. The animals were sacrificed 60 days postoperatively and the pieces containing the replanted teeth were processed and paraffin-embedded. Semi-serial transversally sections were obtained from the middle third of the root and stained with hematoxylin and eosin for histomorphometric analysis. Data were analyzed statistically using Kruskal-Wallis and Dunn's tests. The results showed that root structure and cementum extension were more affected by resorption in group III (p<0.05). All groups were affected by root resorption but the treatment performed in group III was the least effective for its control. The treatment accomplished in groups I and II yielded similar results to each other.

Chemical removal of necrotic periodontal ligament on delayed replanted teeth by sodium hypochlorite: morphological analysis and microhardness indentation test of cementum

“…, Sottovia et al . ); however, the optimal concentration and working time of NaOCl were not determined in these studies. The present results showed that, consistent with previous studies, the necrotic PDL‐dissolving efficacy of NaOCl solution was enhanced by increasing its concentration and extending the working time, but these changes also increased damage to the root surface and cementum.…”

“…, Sottovia et al . ). However, the proper combination of concentration and working time for NaOCl application for PDL removal and its effects on the cementum layer are unknown.…”

An experimental model for studies on delayed tooth replantation and ankylosis in rabbits

“…However, it is not known whether this necrotic tissue should be removed or not before replantation and how this should be performed. There have been suggestions for various substances for topical application on the root surface or in the root canal prior to replantation of teeth with long extra-oral periods (20)(21)(22)(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35)(36). However, current recommendations for clinical management of teeth with long extra-oral storage are still mainly based on best practice experience (16).…”

“…Dogs have been used but also have limitations in availability (25,(33)(34)(35). Mice are more accessible for in vivo experiments (22,26,27,29). However, one must be aware that with smaller animals, the tissue reactions may differ from monkeys and humans.…”

Effect of periodontal ligament removal with gauze prior to delayed replantation in rabbit incisors on rate of replacement resorption

“…These include using a scalpel blade, 22 rubber cup polishing with pumice/water slurry, 23 diamond bur and sandpaper disk 24 or chemically with sodium hypochlorite solution. 25,26 With regard to the removal of necrotic root PDL using sodium hypochlorite, the authors who employed the chemical removal with sodium hypochlorite justify its use because this technique preserves the cementum layer, 25,26 which is an important barrier against the external root resorption. However, although such measures may have an advantage after short-term healing, it has been shown that ankylosis and osseous replacement of the tooth still occur even if the cementum layer is intact.…”