Analyse der Haftkraft in Abhängigkeit von der Konizität des Wurzelkanals
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Philipps-Universität Marburg
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Abstract
2.1 Objective
Endodontics is the dental specialty concerned with the study and therapy of the
dental pulp. The aim is to prevent and treat diseases of the dental pulp and
surrounding periradicular tissues. Among a variety of treatments the root canal
therapy is one of the most common procedures which obtains to eliminate the
infection and to protect the decontaminated teeth from future microbial
invasions with an obturation of the affected root canals (16).
To allow a sufficient removal of the infected structures and to adequately insert
a point – most commonly made of gutta-percha – attached with a fixing material
the root canal dentin has to be filed and shaped with endodontic files. Referring
to this procedure there are numerous instrument systems as well as techniques
which all need to consider two major parameters at the point to operate a
proper filling: The taper and the ISO size.
A correlation among these two relevant factors and their influence on the
strength of adhesive bonding between the root canal dentin and the luting agent
has not been evidenced by studies yet.
2.2 Materials and Methods
60 extracted single-rooted secondary human teeth with a straight root curvature
were sampled out by x-ray studies. According to their complexion the 60
samples were deploied into 6 groups at 10 teeth per group. The teeth were
prepared with tapers of 2%, 4% and 6% with an overall size of ISO 40. The
working length was mathematically defined for any taper to reach a total surface
area of ~18,8 mm² for any prepared specimen.
Comparatively two different luting agents were taken into consideration. BifixSE
(VOCO) as a dual-cured universal self-adhesive resin cement and the combination
of the self-etch dual-cured bond for any type of resin cement
FuturabondU (VOCO) with the dual-cured flowable core build-up and post luting
system RebildaDC (VOCO).
Each of the 6 groups specified the used luting material, the taper and the ISO
sizing in greater detail which led to the following structuralizing:
Gr. A1 [BF2]: BifixSE / .02#40 / 11,5 mm
Gr. B1 [BF4]: BifixSE / .04#40 / 10,0 mm
Gr. C1 [BF6]: BifixSE / .06#40 / 9,0 mm
Gr. A2 [RB2]: RebildaDC / .02#40 / 11,5 mm
Gr. B2 [RB4]: RebildaDC / .04#40 / 10,0 mm
Gr. C2 [RB6]: RebildaDC / .06#40 / 9,0 mm
After that the teeth were decoronated to their particular working length and the
canals were prepared with rotary mechanical file sequences of the BioRace-
(FKG Dentaire SA) and FlexMaster- (VDW) system to their determined
parameters. Throughout this process the canals were flushed with sodium
hypochlorite (NaOCl) as the disinfecting irrigant as well as to debride the canals
from the infected tissue and dried out with paper points in the following.
Customized stainless steal spreaders used as the core material were silicated
(Rocatec, 3M Espe) and inserted with one of the objective luting agents. The
utterly chemical polymerization phase was adhered for 14 days under moist and
light excluded conditions at a temperature of 36°C. The specimens were
subjected to a Pullout test where the required amount of force to dislodge the
spreader was measured in MPa units. For this purpose the universal testing
machine Zwick 1120 (Zwick Roell) was used (41).
Finally the results were statistically analyzed with the SPSS 22.0 (IBM)
software.
2.3 Results
The median for the shear bond strength was in a range within 2,95 MPa (Gr.
A2) and 3,58 MPa (Gr. C2). With a significance level of p [α] ≥ 0,05 the Kruskall-
Wallis test pointed out that the results were not significantly differing in
considseration of neither among all groups (p = 0,32) nor among the subgroups
of the luting agents (Bifix - gr.: p = 0,95; Rebilda - Gr.: p = 0,11). The paired
comparison with the Mann-Whitney U-test allowed a statement if varying tapers
within the same luting agent group or similar tapers in comparison with a
differing luting agent were resulting in diverging values of the determined bond
strength. In the case of both perspectives the results were not significantly
higher or lower.
The analysis of the fracture modes predominantly showed a mixed fractured
mechanism of the spreader decementation. A mininmal shift in favour of an
adhesive failure between the spreader and the luting agent could be noticed for
the groups with a .02 taper (Gr. A1/A2).
2.4 Consclusion
Post canal instrumentation with files of a 2%, 4% or 6% taper neither ensure a
clinically significant increase nor a decrease. This statement could be also
confirmed by comparing different luting agents. For the shear bond strength as
a qualitative factor of a sufficient treatment it is immaterial which taper is used to
prepare the root canal before a proceeded post insertion.
From a critical perspective this conclusion has to be seen in the limitations of
this study. Higher tapers or the appraisal of further fixing materials (e.g. root
canal sealers) might cause significantly differing shear bond strength values in
between the root canal dentin and the exerted agent.
Review
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Dates
Created: 2018Issued: 2018-08-01Updated: 2018-08-01
Faculty
Medizin
Publisher
Philipps-Universität Marburg
Language
ger
Data types
DoctoralThesis
Keywords
adhesive bondingTaperWurzpullout analysisWurzelkanaldentinKonizitätRebilda DCshear bond strengthBifix SEroot canal dentintaperroot canalHaftkraftRebilda DCPulloutverfahrenWurzelkanalAdhäsive BefestigungWurzelkanalbehandlungpoBifix SEpulloutroot canal treatment
DFG-subjects
taperadhesive bondingshear bond strengthpulloutRebilda DCBifix SEroot canalroot canal dentinporoot canal treatmentpullout analysis
DDC-Numbers
610
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Dunker, Constantin: Analyse der Haftkraft in Abhängigkeit von der Konizität des Wurzelkanals. : Philipps-Universität Marburg 2018-08-01. DOI: https://doi.org/10.17192/z2018.0315.