Publications by authors named "K T Wrbas"

47 Publications

Comparison of the efficacy of different Ni-Ti instruments in the removal of gutta-percha and sealer in root canal retreatment.

Indian J Dent Res 2020 Jul-Aug;31(4):579-584

Department of Endodontics, Center for Operative Dentistry and Periodontology, University of Dental Medicine and Oral Health, Danube Private University (DPU), Krems, Austria; Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Oral and Maxillofacial Surgery, Medical Center, University of Freiburg, Freiburg i.Br., Germany.

Aims: To evaluate and compare the efficacy of four rotary instrumentation systems in root canal retreatment and to determine retreatment time.

Materials And Methods: To achieve the purpose of this study, canals of 60 distal roots in mandibular molar teeth were selected and randomly divided into four groups A, B, C and D (n = 15). Using step-back technique, the canals were prepared and filled with gutta-percha and AH Plus employing cold lateral compaction technique. The root filling material was removed with the following retreatment systems: Group A: Mtwo R, group B: D-RaCe, group C: ProTaper R and group D: R-Endo. In order to record retreatment time, a stopwatch was used. The samples were split longitudinally, examined under a stereomicroscope, photographed and assessed with AutoCAD software. Finally, the percentages of remaining filling material were calculated and the extracted data were analyzed using one-way ANOVA and Tukey HSD test.

Results: All examined groups showed traces of remaining filling material within the canals. No statistically significant difference was found among the four groups in the coronal, middle, and apical thirds. The same result was obtained with regard to retreatment time (P > 0.05). However, within each one of the groups, significant difference was observed in the three regions (P < 0.05).

Conclusions: Based on the findings of this study, none of the examined systems could completely remove root filling material from the root canals. However, they were all found to be effective in this regard. The most amount of remaining filling material was found in the apical third.
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October 2020

Guided endodontic access of a calcified mandibular central incisor using a software-based three-dimensional treatment plan.

Int J Comput Dent 2019 ;22(3):273-281

This case report describes the digital and clinical workflow of a guided endodontic access approach in a mandibular central incisor with pulp canal calcification (PCC). The access to the remaining pulp space was planned virtually using cone beam computed tomography (CBCT) and the Sicat Endo software (Sicat, Bonn, Germany). Sicat produced the corresponding Accessguide after matching a digitized cast model and the virtual treatment plan. The clinical access was prepared using a carbide bur with a diameter of 1.2 mm. After the root canal was localized successfully, it was disinfected chemomechanically, dried, and obturated using a warm vertical compaction technique.
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October 2019

Accuracy of Software-Based Three-Dimensional Root Canal Length Measurements Using Cone-Beam Computed Tomography.

Eur Endod J 2019 13;4(1):28-32. Epub 2018 Nov 13.

Department of Prosthetic Dentistry, Center for Dental Medicine, Medical Center, University of Freiburg, Freiburg, Germany.

Objective: This study aims to evaluate the accuracy of three-dimensional root canal length measurements performed by dentists with different experience levels using a special software based on cone beam com-puted tomography (CBCT).

Methods: A CBCT scan of an artificial resin maxillary molar was used to train dentists (n=65) in using the software (3D Endo, DentsplySirona, Ballaigues, Switzerland) as part of a continuing education course. At the beginning, each participant completed a questionnaire on endodontic and CBCT experiences. After com-prehensive instructions, each participant performed an entire three-dimensional treatment plan by tracing the root canal anatomy between the apical foramen and the center of the canal orifice and simulating a straight-line access. The final root canal length was indicated after the virtual rubber stop of a simulated instrument was adapted to the adjoining cusp. To evaluate the individual accuracy in terms of trueness and precision, differences between the three-dimensional planning and the actual root canal length (ARCL) were calculated, and statistically analyzed.

Results: Mean absolute differences between the measurements with the 3D Endo™ software (n=260) and the ARCL were 0.30±0.22 mm. All measurements were within a limit of ±1 mm. The accuracy of root canal length measurements was significantly influenced by the type of root canal (p<0.0001). The smallest devia-tions were observed for the palatal root canal (0.18±0.13 mm), followed by the mesiobuccal (0.26±0.22 mm), the distobuccal (0.32±0.17 mm), and the second mesiobuccal root canal (0.46±0.24 mm).

Conclusion: Within the limitations of this study, the 3D Endo software enables reproducible and accurate root canal length measurements as part of a three-dimensional endodontic treatment plan. However, mea-surements should always be clinically verified, as root canal morphology has a statistically significant influence.
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November 2018

Comparison of two cone-beam computed tomography systems in the visualization of endodontic structures.

Swiss Dent J 2017 ;127(3):221-229

Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Medical Center, University of Freiburg, Freiburg i.Br., Germany

An important part of endodontic diagnosis and treatment is the adequate visualization of root canal anatomy. The objective of the present study was to compare two different three-dimensional cone-beam computed tomography (CBCT) systems, Scanora 3D and 3D Accuitomo 170, with respect to their visualization of endodontic canal systems and potential pathological alterations. Seventy extracted human teeth were investigated with regard to the radiographic detection of number of root canals, lateral canals, root canal fillings and posts, vertical root fractures, and the occurrence of image artifacts. For each evaluation parameter under investigation the radiographic diagnoses obtained by the two different CBCT systems under investigation were similarly accurate, without statistically significant differences. The evaluation of teeth containing highdensity foreign materials was impaired for both CBCT systems because of image artifacts. However, a difference between the CBCT systems was not observed. In conclusion, both CBCT systems were found to be similarly suitable for the visualization of endodontic structures in vitro.
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September 2017

Antimicrobial influence of different root canal filling techniques in experimentally infected human root canals.

Quintessence Int 2017 ;48(4):273-280

Objective: The aim of the present study was to evaluate the antimicrobial influence of different root canal filling techniques using gutta-percha and an epoxy resin-based sealer in experimentally infected root canals of extracted human teeth.

Method And Materials: In total, 96 intact sterilized, permanent human anterior teeth and premolars with single patent root canals were prepared and infected with a clinical isolate of Enterococcus faecalis. After 72 hours, all root canals were sampled using three sterile paper points. The tooth specimens were randomly divided into three groups and a control of 24 specimens each, according to the respective obturation techniques: lateral condensation (LC group), ProTaper Thermafil (PT group), and vertical compaction technique (VC group). AH Plus was used as sealer. The control group was left untreated (without root canal filling). After 7 days root canal fillings were removed and collected. The root canals were sampled using three sterile paper points and dentin chips were obtained from the root canal walls. The samples were cultured on blood agar, and colony forming units were counted.

Results: All root canal filling techniques significantly reduced bacterial viability, eliminating more than 99.9% of E faecalis. In the LC group, three (13%) root canals were culture negative. In the PT group, 21 (88%) root canals and in the VC group 15 (54%) were culture negative.

Conclusion: All root canal filling techniques significantly reduced E faecalis in root canals. In cases where warm filling techniques can be applied, these should be preferred to cold obturation.
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October 2018