Comparison among four commonly used demineralizing agents for root conditioning: a scanning electron microscopy

Dental roots that have been exposed to the oral cavity and periodontal pocketenvironment present superficial changes, which can prevent connective tissuereattachment. Demineralizing agents have been used as an adjunct to the periodontaltreatment aiming at restoring the biocompatibility of roots.

Objective

This study compared four commonly used demineralizing agents for their capacity ofremoving smear layer and opening dentin tubules.

Methods

Fifty fragments of human dental roots previously exposed to periodontal diseasewere scaled and randomly divided into the following groups of treatment: 1) CA:demineralization with citric acid for 3 min; 2) TC-HCl: demineralization withtetracycline-HCl for 3 min; 3) EDTA: demineralization with EDTA for 3 min; 4) PA:demineralization with 37% phosphoric acid for 3 min; 5)Control: rubbing of salinesolution for 3 min. Scanning electron microscopy was used to check for thepresence of residual smear layer and for measuring the number and area of exposeddentin tubules.

Results

Smear layer was present in 100% of the specimens from the groups PA and control;in 80% from EDTA group; in 33.3% from TC-HCl group and 0% from CA group. The meannumbers of exposed dentin tubules in a standardized area were: TC-HCl=43.8±25.2;CA=39.3±37; PA=12.1±16.3; EDTA=4.4±7.5 and Control=2.3±5.7. The comparison showedsignificant differences between the following pairs of groups: TC-HCl and Control;TC-HCl and EDTA; CA and Control; and CA and EDTA. The mean percentages of areaoccupied by exposed dentin tubules were: CA=0.12±0.17%; TC-HCl=0.08±0.06%;PA=0.03±0.05%; EDTA=0.01±0.01% and Control=0±0%. The CA group differedsignificantly from the others except for the TC-HCl group.

Conclusion

There was a decreasing ability for smear layer removal and dentin tubule wideningas follows: AC>TC-HCl>PA>EDTA. This information can be of value as anextra parameter for choosing one of them for root conditioning.