@article{KrugVollandReichetal.2020,
  author    = {Krug, Ralf and Volland, Julian and Reich, Sebastian and Soliman, Sebastian and Connert, Thomas and Krastl, Gabriel},
  title     = {Guided endodontic treatment of multiple teeth with dentin dysplasia: a case report},
  series = {Head \& Face Medicine},
  volume    = {16},
  journal   = {Head \& Face Medicine},
  doi       = {10.1186/s13005-020-00240-4},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-230271},
  year      = {2020},
  abstract  = {Background To report the outcome of guided endodontic treatment (GET) of a case of dentin dysplasia with pulp canal calcification (PCC) and apical periodontitis based on the use of a 3D-printed template designed by merging cone-beam computed tomography (CBCT) and surface scan data. Case presentation A 12-year old female with radicular dentin dysplasia type I (DD-1) presented for endodontic treatment. Radiography revealed PCC in all teeth and apical radiolucency in seven teeth (12, 15, 26, 31, 32, 36 and 46). Tooth 36 had the most acute symptoms and was thus treated first by conventional access cavity preparation and root canal detection. Despite meticulous technique, the distal and mesiolingual canals were perforated. The perforations were immediately repaired with mineral trioxide aggregate, and the decision was made to switch to guided endodontic treatment for the remaining 6 teeth. CBCT and intraoral surface scans were acquired and matched using coDiagnostix planning software (Dental Wings Inc.), the respective drill positions for root canal location were determined, and templates were virtually designed and 3D-printed. The template was positioned on the respective tooth, and a customized drill was used to penetrate the calcified part of the root canal and perform minimally invasive access cavity preparation up to the apical region. All root canals were rapidly and successfully located with the templates. At 1-year follow-up, clear signs of apical healing were present in all treated teeth. Conclusions In patients with dentin dysplasia, conventional endodontic therapy is challenging. GET considerably facilitates the root canal treatment of teeth affected by dentin dysplasia.},
  language  = {en}
}
@article{KrugOrtmannReichetal.2022,
  author    = {Krug, Ralf and Ortmann, C. and Reich, S. and Hahn, B. and Krastl, G. and Soliman, S.},
  title     = {Tooth discoloration induced by apical plugs with hydraulic calcium silicate-based cements in teeth with open apices-a 2-year in vitro study},
  series = {Clinical Oral Investigations},
  volume    = {26},
  journal   = {Clinical Oral Investigations},
  number    = {1},
  issn      = {1436-3771},
  doi       = {10.1007/s00784-021-04009-0},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-268856},
  pages     = {375-383},
  year      = {2022},
  abstract  = {Objectives To assess tooth discoloration induced by different hydraulic calcium silicate-based cements (HCSCs), including effects of blood and placement method. Materials and methods Eighty bovine teeth cut to a length of 18 mm (crown 8 mm, root 10 mm) were randomly assigned to 10 groups (n = 8), receiving orthograde apical plug treatment (APT). Apical plugs were 4 mm in length and made of ProRoot MTA (Dentsply), Medcem MTA (Medcem), TotalFill BC RRM Fast Set Putty (Brasseler), or Medcem Medical Portland Cement (Medcem) plus bismuth oxide (Bi2O3) with and without bovine blood. Further, orthograde (with or without preoperative adhesive coronal dentin sealing) and retrograde APT were compared. Teeth were obturated with gutta-percha and sealer, sealed with composite and stored in distilled water. Tooth color was measured on apical plug, gutta-percha/sealer, and crown surface before treatment versus 24 h, 1, 3, 6, 12, and 24 months after treatment by spectrophotometry. Color difference (ΔE) values were calculated and analyzed by Shapiro-Wilk test, ANOVA with post hoc tests, Friedman test, t test, and post hoc tests with Bonferroni correction (α = .05). Results Tooth discoloration occurred in all groups with no significant differences between HCSCs (p > .05). After 24 months, color changes were prominent on roots but insignificant on crowns. Blood contamination induced a significantly decreased luminescence (p < .05). Blood had a stronger impact on tooth color than Bi2O3. No relevant effects of retrograde placement (p > .05) or preoperative dentin sealing (p > .05) were detected. Conclusions Apical plugs of the tested HCSCs cause discoloration of bovine roots, but not discoloration of bovine tooth crowns within a 24-month period. Clinical relevance APT should be performed carefully while avoiding direct contact with the coronal dentin, and in that case no aesthetic impairments occur.},
  language  = {en}
}
@article{HahnHaubitzKrugetal.2022,
  author    = {Hahn, Britta and Haubitz, Imme and Krug, Ralf and Krastl, Gabriel and Soliman, Sebastian},
  title     = {Influence of matrix type on marginal gap formation of deep class II bulk-fill composite restorations},
  series = {International Journal of Environmental Research and Public Health},
  volume    = {19},
  journal   = {International Journal of Environmental Research and Public Health},
  number    = {9},
  issn      = {1660-4601},
  doi       = {10.3390/ijerph19094961},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-270712},
  year      = {2022},
  abstract  = {Background: To test the hypothesis that transparent matrices result in more continuous margins of bulk-fill composite (BFC) restorations than metal matrices. Methods: Forty standardized MOD cavities in human molars with cervical margins in enamel and dentin were created and randomly assigned to four restorative treatment protocols: conventional nanohybrid composite (NANO) restoration (Tetric EvoCeram, Ivoclar Vivadent, Schaan, Liechtenstein) with a metal matrix (NANO-METAL) versus transparent matrix (NANO-TRANS), and bulk-fill composite restoration (Tetric EvoCeram Bulk Fill, Ivoclar Vivadent, Schaan, Liechtenstein) with a metal matrix (BFC-METAL) versus transparent matrix (BFC-TRANS). After artificial aging (2500 thermal cycles), marginal quality was evaluated by scanning electron microscopy using the replica technique. Statistical analyses were performed using the Mann-Whitney U-test and Wilcoxon test. The level of significance was p < 0.05. Results: Metal matrices yielded significantly (p = 0.0011) more continuous margins (46.211\%) than transparent matrices (27.073\%). Differences in continuous margins between NANO (34.482\%) and BFC (38.802\%) were not significant (p = 0.56). Matrix type did not influence marginal gap formation in BFC (p = 0.27) but did in NANO restorations (p = 0.001). Conclusion: Metal matrices positively influence the marginal quality of class II composite restorations, especially in deep cavity areas. The bulk-fill composite seems to be less sensitive to the influence of factors such as light polymerization and matrix type.},
  language  = {en}
}
@article{ReichardtKrugBornsteinetal.2021,
  author    = {Reichardt, Elisabeth and Krug, Ralf and Bornstein, Michael M. and Tomasch, J{\"u}rgen and Verna, Carlalberta and Krastl, Gabriel},
  title     = {Orthodontic forced eruption of permanent anterior teeth with subgingival fractures: a systematic review},
  series = {International Journal of Environmental Research and Public Health},
  volume    = {18},
  journal   = {International Journal of Environmental Research and Public Health},
  number    = {23},
  issn      = {1660-4601},
  doi       = {10.3390/ijerph182312580},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-250192},
  year      = {2021},
  abstract  = {(1) Background: To assess orthodontic forced eruption (OFE) as a pre-restorative procedure for non-restorable permanent teeth with subgingival dental hard tissue defects after dental trauma. (2) Methods: A systematic electronic search of three databases, namely, MEDLINE, Cochrane Library, and EMBASE, revealed a total of 2757 eligible publications. Randomized controlled clinical trials (RCT), retro- and prospective clinical studies, or case series (with a minimum of three patients) were reviewed. (3) Results: Thirteen full-text papers were included: one RCT, one prospective clinical trial, two retrospective cohort studies, and nine case series. Within case series, statistical significance between age and cause of fracture (p < 0.03) was determined. The mean extrusion rate of OFE was 1.5 mm a week within a four to six weeks treatment period followed by retention. Three OFE protocols for maxillary single teeth are available: 1. OFE without migration of gingiva and alveolar bone, 2. OFE with gingival migration and slight alveolar bone migration, and 3. OFE with migration of both gingiva and alveolar bone. (4) Conclusions: The current state of the evidence suggests that OFE is a feasible pre-treatment option for non-restorable permanent teeth. OFE can promote the migration of tooth surrounding hard and soft tissues in the esthetic zone. Root resorption does not seem to be a relevant side effect of OFE.},
  language  = {en}
}
@article{LudwigReymusWinkleretal.2023,
  author    = {Ludwig, Julia and Reymus, Marcel and Winkler, Alexander and Soliman, Sebastian and Krug, Ralf and Krastl, Gabriel},
  title     = {Root maturation of an immature dens invaginatus despite unsuccessful revitalization procedure: a case report and recommendations for educational purposes},
  series = {Dentistry Journal},
  volume    = {11},
  journal   = {Dentistry Journal},
  number    = {2},
  issn      = {2304-6767},
  doi       = {10.3390/dj11020047},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-304108},
  year      = {2023},
  abstract  = {Background: The clinical management of teeth with complex dens invaginatus (DI) malformations and apical periodontitis may be challenging due to the lack of routine. The aim of this case report is to describe the endodontic treatment of an immature tooth with DI and to discuss strategies for preclinical training for teeth with such malformations. Case report: A 9-year-old male presented with an immature maxillary incisor with DI (Oehlers Type II) and apical periodontitis which was diagnosed by cone beam computed tomography (CBCT). Revitalization was initially attempted but then abandoned after failure to generate a stable blood clot. Nevertheless, considerable increase in both root length and thickness could be detected after medication with calcium hydroxide followed by root canal filling with MTA as an apical plug. Conclusions: The endodontic management of teeth with DI requires thorough treatment planning. In immature teeth, under certain conditions, root maturation may occur even with conventional apexification procedures. From an educational perspective, different strategies including CBCT and 3D-printed transparent tooth models for visualization of the complex internal morphology and redesigned 3D-printed replica with various degrees of difficulty for endodontic training, can be used to overcome the challenges associated with endodontic treatment of such teeth.},
  language  = {en}
}