Analysis of the effectiveness of calcium hydroxide removal with variation of technique and solvent vehicles.
BACKGROUND
Calcium hydroxide (Ca(OH)2) paste filling is largely used as intra-canal medication and can be combined with different vehicles. Removal of that paste should be preceded by obturation, to avoid the occurrence of apical microleakage.


OBJECTIVE
To evaluate the efficiency of removal of pulp Ca(OH)2, from using different vehicles (water, propylene glycol) and removal techniques (mechanical and ultrasonic).


METHODS
Twenty-four premolars and four human incisors were prepared with step-back technique and divided into six groups according to the removal techniques and vehicles used: Group distilled water/mechanical removal, Group distilled water/ultrasonic removal, Group propylene/mechanical removal, Group propylene/ultrasonic removal, negative control group, and positive control group. The differences between groups were analyzed.


METHODS
The teeth were prepared by step-back technique. The samples were evaluated by stereomicroscopy, using a scoring system for the evaluation of residues in the canal.


METHODS
Mann-Whitney test was used to a comparison between groups with the same vehicle. For comparison between groups, regardless of the vehicle, we used the Kruskal-Wallis test, considering P < 0.05 for both tests.


RESULTS
Groups using distilled water or propylene glycol did not show statistically significant results. When the groups were compared, differences were detected between groups distilled water/propylene and mechanical removal/removal ultrasonic, with the first featuring superior performance.


CONCLUSIONS
None of the removal techniques employed in this study was able to completely remove Ca(OH)2 from the root canal. However, the use of distilled water as a vehicle and ultrasonic removal presented the best performance.
Paula Dias
PD
Lins
Barbara Catarina Lima
BC
Nogueira
Nathÿlia Carolina Fernandes
NC
Fagundes
Fernando Romualdo Bezerra
FR
Silva
Laboratory of Functional and Structural Biology, Institute of Biological Sciences, Federal University of Pará, Belém-Pará, Brazil.
Rafael Rodrigues
RR
Lima
D002126:Calcium Hydroxide / Q000737:chemistry*; D004708:Endodontics / Q000379:methods*; D006801:Humans; D012388:Root Canal Irrigants / Q000737:chemistry*; D018915:Root Canal Preparation / Q000379:methods*; D012997:Solvents
D012388:Root Canal Irrigants; D012997:Solvents; D002126:Calcium Hydroxide