Abstract
In the present in vitro study the sealing ability of root canal fillings was
evaluated on upper single-rooted praemolars with two root canals, using a dye
penetration test. It was examined, whether the sealing abilities of root canal
fillings could be improved by apicectomy or by apicectomy with additional retrograde
filling. Moreover, the influence of the different root canal configurations
on the results was investigated.
For this purpose, 102 upper single rooted praemolars with two canals of type
II (group A; n=51) and type IV (group B; n=51) configuration were selected.
The teeth were randomly divided into 6 subgroups (IA, IIA, IIIA, IB, IIB, IIIB),
consisting of 17 teeth each. The root canals of all teeth were uniformly enlarged
and subsequently filled by means of lateral condensation. The teeth of group
II and group III were apicectomized. The teeth of group III additionally received
retrograde fillings (Ketac-Fil®). Group I served as control group.
After storage in water (30 days, 37 °C) all teeth were immersed for 48 hours
(37 °C) in methylene blue. Then each root was cross-sectioned and the depth
of dye-penetration was measured. Furthermore all teeth were examined for lateral
canals, using an optical microscope. The obtained data were statistically analysed
at a=95%.
Mann-Whitney-Test revealed a significantly lower dye penetration for the root
fillings of both subgroups II compared to the root fillings of both subgroups
I and both subgroups III (p=0,000 and p=0,000, resp., for groups A; p=0,000
and p=0,000, resp., for groups B). The same test showed a significantly lower
dye penetration in both groups I compared to both groups III (p=0,024 and p=0,008,
resp.). The comparision between the two root canal configuration within the
groups I, II and III did not reveal any significant differences concerning the
sealing ability. It was observed, that teeth with lateral canals showed a deeper
dye penetration. With regard to their sealing ability against methylene blue
the apicectomized teeth (group II) showed the best results. The transfer of
results of dye penetration studies on the clinical situation must be considered
critically.
The worst results could be observed in the apicectomized teeth with additional
retrograde fillings. Concerning the apical sealing ability the application of
additional retrograde fillings appears to be problematic and should be reexamined
in future studies.
|
