@article{SchneiderHoehneSchneideretal.2022, author = {Schneider, Sonja Jasmin Maria and H{\"o}hne, Christian and Schneider, Martin and Schmitter, Marc}, title = {Photoacoustic tomography versus cone-beam computed tomography versus micro-computed tomography: Accuracy of 3D reconstructions of human teeth}, series = {PloS One}, volume = {17}, journal = {PloS One}, number = {12}, doi = {10.1371/journal.pone.0274818}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-301437}, year = {2022}, abstract = {Objectives In this in-vitro study, teeth were imaged using photoacoustic tomography (PAT), cone-beam computed tomography (CBCT), and micro-computed tomography (μ-CT). The study had aim: to identify the best wavelength for PAT images to determine the accuracy of the three imaging methods, and to determine whether PAT images of teeth can achieve acceptable reconstruction quality. Methods Nineteen human mandibular single-rooted incisors were extracted from patients with trauma or periodontitis. To determine the best wavelength for acquiring photoacoustic images, all 19 teeth were scanned in vitro with PAT, using different laser wavelengths between 680 and 960 nm. The images were analyzed using image analysis software. To assess the accuracy of PAT and compare it with the accuracy of CBCT, each tooth was also scanned in vitro using CBCT and the reference standard technique of μ-CT. Subsequently, three different three-dimensional models, one for each imaging technique, were created for each tooth. Finally, the three different three-dimensional models acquired for the same tooth were matched and analyzed regarding volume and surface. Results The highest quality tooth images were achieved using the 680 nm wavelength, which showed the best contrast ratio. The full geometry of the dental root (μ-CT compared with PAT) could be visualized with relative standard deviations of 0.12 mm for the surface and -7.33 mm3 for the volume (n = 19). The full geometry of the dental root (μ-CT compared with CBCT) could be visualized with relative standard deviations of 0.06 mm for the surface and -14.56 mm3 for the volume (n = 19). The difference between the PAT-μ-CT group and CBCT-μ-CT group regarding the total average of the root surface area was not significant (p>0.06). Conclusion Images, which were acquired using PAT at 680nm showed the best contrast ration, enabling the identification of dentin, cementum and the dental pulp. No significant differences were found between the PAT-μ-CT group and CBCT-μ-CT group regarding the total average of the RSA and the total volume. Thus, three-dimensional reconstructions based on in-vitro PAT are already of acceptable reconstruction quality.}, language = {en} } @article{KauffmannHoehneAssafetal.2020, author = {Kauffmann, Frederic and H{\"o}hne, Christian and Assaf, Alexandre Thomas and Vollkommer, Tobias and Semmusch, Jan and Reitmeier, Aline and Stein, Jamal Michel and Heiland, Max and Smeets, Ralf and Rutkowski, Rico}, title = {The influence of local pamidronate application on alveolar dimensional preservation after tooth extraction — an animal experimental study}, series = {International Journal of Molecular Sciences}, volume = {21}, journal = {International Journal of Molecular Sciences}, number = {10}, issn = {1422-0067}, doi = {10.3390/ijms21103616}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-285173}, year = {2020}, abstract = {The aim of this randomized, controlled animal exploratory trial was to investigate the influence of local application of aminobisphosphonate pamidronate during the socket preservation procedure. Mandibular premolars were extracted in five G{\"o}ttingen minipigs. Two animals underwent socket preservation using BEGO OSS (n = 8 sockets) and three animals using BEGO OSS + Pamifos (15 mg) (n = 12 sockets). After jaw impression, cast models (baseline, eight weeks postoperative) were digitized using an inLab X5 scanner (Dentsply Sirona) and the generated STL data were superimposed and analyzed with GOM Inspect 2018 (GOM, Braunschweig). After 16 weeks, the lower jaws were prepared and examined using standard histological methods. In the test group (BEGO OSS + pamidronate), buccooral dimensional loss was significantly lower, both vestibulary (-0.80 ± 0.57 mm vs. -1.92 ± 0.63 mm; p = 0.00298) and lingually (-1.36 ± 0.58 mm vs. -2.56 ± 0.65 mm; p = 0.00104) compared with the control group (BEGO OSS). The test group showed a significant difference between vestibular and lingual dimensional loss (p = 0.04036). Histology showed cortical and cancellous bone in the alveolar sockets without signs of local inflammation. Adjuvant application of pamidronate during socket preservation reduces alveolar dimensional loss significantly. Further investigations with regard to dose-response relationships, volume effects, side effects, and a verification of the suitability in combination with other bone substitute materials (BSMs) are necessary.}, language = {en} } @article{HoehneSchwarzbauerSchmitter2020, author = {H{\"o}hne, Christian and Schwarzbauer, Raphael and Schmitter, Marc}, title = {Introduction of a new teaching concept for crown preparation with 3D printed teeth}, series = {European Journal of Dental Education}, volume = {24}, journal = {European Journal of Dental Education}, number = {3}, doi = {10.1111/eje.12532}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-218133}, pages = {526 -- 534}, year = {2020}, abstract = {Introduction For both students and teachers, it is challenging to learn and teach a correct crown preparation. The purpose of this study was the design, feasibility and evaluation of a 3D printed tooth model with internal preparation for dental education in crown preparation and to analyse the quality of the prepared printed teeth in comparison with prepared standard model teeth. Materials and methods A printable tooth was designed and printed by a stereolithographic printer. 38 fourth-year dental students in the first clinical course in prosthodontics were trained in a voluntary course using printed teeth. Different aspects of the printed tooth were evaluated by a questionnaire using German school grades (1 best to 5 worst). The quality of the preparation with the printed teeth and standard training teeth was also rated in an evaluation form done by an expert group consisting of five experienced dentists. Results The workflow was feasible and cost-effective for the production of the teeth. The overall rating of the printed tooth was {\O} 2.0 ± 0.34 in the questionnaire completed by the students. The students rated the printed tooth model ({\O} 2.1 ± 0.85) as significantly better than the standard model tooth ({\O} 3.3 ± 0.77; P = .000). The students reported great benefits in the use of this model tooth, for example valuable replacement of a standard model and real teeth, direct control of material loss. The quality of the preparation was evaluated by the expert group as significantly better with an overall mean grade of {\O} 2.6 ± 0.37 for the printed teeth compared to {\O} 2.9 ± 0.42 for the standard model teeth (P = .000). Conclusions The feasibility of this teaching concept was confirmed. The students favoured to work on the innovative 3D-teeth with internal preparation, emphasising the usefulness of this technique in dental education. The expert group confirmed also the significant training effect of this tooth model in contrast to a standard model tooth.}, language = {en} } @article{HoehneDickhautSchmitter2020, author = {H{\"o}hne, Christian and Dickhaut, Nora and Schmitter, Marc}, title = {Introduction of a new teaching concept for dentin post preparation with 3D printed teeth}, series = {European Journal of Dental Education}, volume = {24}, journal = {European Journal of Dental Education}, number = {3}, doi = {10.1111/eje.12528}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-215586}, pages = {499 -- 506}, year = {2020}, abstract = {Introduction The preparation for dentin posts is difficult and hard to learn. There are currently no reproducible simulation models to train this clinical procedure. The purpose of this study was the design, feasibility and evaluation of a three-dimensional (3D) printed tooth model for the pre-clinical teaching of students. Materials and methods A printable tooth was designed and printed by a stereolithographic printer. A total of 48 fourth-year dental students in the first clinical course in prosthodontics were trained in a voluntary hands-on course on 4 similar printed teeth. The students used standard model teeth and real-teeth models during their education. They had experience in caries removement and root canal treatment on real patients. Root perforations were counted for every attempt. The different benefits of the 3D printed tooth were evaluated by a questionnaire using German school grades from 1 (best) to 6 (worst). Results The overall rating of the printed tooth was {\O}1.9 ± 0.3. The item "suitable exercise option" was rated {\O}2.0 ± 0.8, and the teeth were "easy to use" {\O}1.9 ± 0.9. The item "realistic approach to dentin post preparation" was rated {\O}2.1 ± 0.8, and the teeth showed the "shortcomings at a root perforation" {\O}1.5 ± 0.6. The students reported to have much more motivation and enthusiasm to improve their skills with the printed teeth {\O}2.1 ± 0.9. They had a strong desire to include these teeth in their pre-clinical education before the first patient treatment {\O}1.6 ± 0.8. The success rate of the dentin post preparation was significantly better for the second 25\% (P = .047) and fourth 48\% (P = .04) attempt. Conclusions The feasibility of this teaching concept was confirmed. The students had the possibility to learn a correct dentin post preparation on a printed tooth model. The learning effect with this tooth model was rated as good to very good by the questionnaire.}, language = {en} }