The purpose of this clinical study was to assess the feasibility of forced orthodontic extrusion with the Tissue Master Concept to retain subgingivally fractured teeth as abutments for which extraction and replacement would be equal treatment opportunities. Participants were recruited from a group of consecutive patients in need of prosthodontic rehabilitation. In total, 36 deeply destroyed teeth in 31 patients underwent forced orthodontic extrusion with forces exceeding 50 g to reestablish biologic width and ensure a 2-mm dentin-ferrule design prior to single-crown restoration. The primary endpoint was the success of the extrusion in terms of the ability to restore the respective abutment tooth. Information about overall treatment time, frequency, and reasons for failure were collected. Four patients dropped out of the treatment. For the remaining 27 participants, data were fully collected. The amount of extrusion ranged between 2 and 6 mm (3.5 ± 0.9 mm), and the mean duration until retention was 20 ± 12 days. On average, patients returned three (± 3) times for control visits after extrusion. Adhesive failure (n = 6) and orthodontic relapse (n = 2) were the most frequent complication types. Forced orthodontic extrusion may be a useful tool to restore teeth evaluated as nonrestorable.

Aim: To compare the planned implant position (PIP) with the transferred implant position (TIP) after fully guided implant placements in single-tooth gaps. Materials and methods: Dental implant placements were planned using two different implant systems (Camlog Screw-Line [C-SL] and Straumann Bone Level Tapered [S-BLT]), and two different planning software programs (SMOP and coDiagnostiX). All implants were placed according to fully guided protocols, and intraoral scans were performed intraoperatively. For the comparison of PIP and TIP, scan data were imported to Geomagic Control X (GCX) software and accuracies were evaluated. Deviations were reported in a coordinate system (x- [mesiodistal], y- [vestibulo-oral], and z- [vertical] axis) at entry points and apices. Total deviations, including angular deviations, were calculated with GCX. For statistical analysis, the level of significance was set to P < 0.05. Results: Twenty-six patients received 26 implants. Mean 3D deviation at the implant’s entry point was 0.61 mm ± 0.28 for C-SL and 0.63 mm ± 0.24 for S-BLT. For the implant’s apex, mean 3D deviation of 0.96 mm ± 0.41 was documented for C-SL and 1.04 mm ± 0.34 for S-BLT. Mean angular deviation was 2.58 degrees ± 1.40 for C-SL and 2.89 degrees ± 1.12 for S-BLT. Statistical analysis revealed no significant differences between implant systems, but showed significant deviations regarding the z-axis, both at entry point and apex (P < 0.05). Conclusions: Fully guided implant placements in single-tooth gaps provide accurate results. Due to significant vertical deviations, reevaluation of both drilling and insertion depths prior to implant installation should be considered. Maintenance of 1.5- to 2-mm safety distances to critical structures was confirmed. Keywords: dental implants, static navigation, CAD/CAM, computer-assisted, computer-assisted implant surgery, backward planning

Maintaining and restoring teeth exhibiting subgingival or even subcrestal defect extensions represent a common problem in daily practice. Such teeth are often deemed “unrestorable” due to a significant hard tissue loss and defect locations violating the biologic width. In order to achieve a sufficient 2-mm-ferrule design and reestablish the biologic width, both surgical crown lengthening and orthodontic extrusion have been suggested. However, surgical crown lengthening has a negative effect on the attachment level of adjacent teeth as well as esthetic disadvantages particularly in the esthetic zone. Therefore, orthodontic extrusion might be considered as a valid therapeutic alternative since gingival architecture is maintained. While most orthodontic appliances are too complex for daily application, forced orthodontic extrusion by means of the Tissue Master Concept might be a cost- and time-effective approach due to advances in adhesive and computer-assisted dentistry. This clinical case series illustrates the methodology of the rather straightforward Tissue Master Concept in specific clinical situations that may occur in clinical routine. Keywords:  forced eruption, orthodontic extrusion, tooth extrusion

The outcome in the treatment of furcation defects is often unsatisfactory. The reasons are morphologic and pathologic peculiarities as well as extensive changes in shape caused by resective treatment of periodontal lesions in multi-rooted teeth. Therefore, augmentative strategies are suggested to improve the prognosis. However, the success rate decreases with increasing severity of the disease. In contrast, if the affected roots are not extracted but are extruded after hemi- or trisection, this leads to a coronal displacement of the disease process and a significantly improved situation for hygiene. At the same time, the resection of inflammatory tissue of the periodontal pockets is accompanied by vertical and horizontal bone apposition. The results are predictable and stable in the long term. The burden for the patient is low. ((Quintessence Int 2022;53: 884–891; Originally published (in German) in Quintessenz Zahnmedizin 2020; 71(9): 1024–1032; doi: 10.3290/j.qi.b3418205) Keywords: extrusion, fibrotomy, furcation defects, replantation of root segments, regeneration, long-term stability

Die unmittelbare bakteriendichte koronale Versiegelung des Wurzelkanalsystems sowie die Herstellung der Kaufunktion sind nach einer adäquaten endodontischen Behandlung grundlegende Faktoren für den langfristigen Erhalt dieser Zähne. Bei der Auswahl der Restauration wird dem Faktor Substanzverlust neben den Parametern Zahntyp, Attachmentverlust und Kronen-Wurzel-Verhältnis sowie prothetische Gesamtbehandlungsplanung eine wesentliche Bedeutung beigemessen. Zusammengenommen bestimmen diese Faktoren die Entscheidung über direkte oder indirekte Restaurationen sowie über die Notwendigkeit der Verwendung eines Wurzelkanalstiftes. Die postendodontische Restauration sollte als integraler Bestandteil der endodontischen Behandlung angesehen werden und dementsprechend zeitnah erfolgen – idealerweise innerhalb von vier Monaten nach der Wurzelkanalfüllung. Keywords: Postendodontische Versorgung, wurzelkanalbehandelte Zähne, Wurzelkanalstifte, adhäsive Befestigung, forcierte Extrusion

The restoration of severely damaged teeth challenges dental practitioners because defects are often located at the subcrestal level. In these cases, surgical crown lengthening or orthodontic extrusion procedures are deemed necessary to maintain the biologic width and respect a sufficient ferrule design after preparation. Considering the negative effects of invasive surgical therapy—such as the reduction of alveolar bone support of the neighboring teeth—forced extrusion might be a valid therapeutic alternative. This clinical case report illustrates forced orthodontic extrusion with a minimally invasive appliance that is applicable in daily clinical routine.

Purpose: The aim of this ex-vivo study was to evaluate the load capacity of direct or indirect endodontically restored maxillary central incisors with Class III defects, with or without glass-fiber posts. Materials and Methods: Seventy-two extracted human maxillary central incisors were endodontically treated and bi-proximal Class III cavities were prepared. Specimens were randomly allocated to six groups (n = 12): direct restoration with composite (C); direct restoration with composite and additional glass-fiber post (CP); ceramic veneer restoration (V), ceramic veneer restoration and additional glass-fiber post (VP), ceramic crown restoration (Cr), ceramic crown restoration and additional glass-fiber post (CrP). Specimens were exposed to thermomechanical loading (TML: 1.2 million cycles, 1 to 50 N; 6000 thermal cycles between 5°C and 55°C for 1 min each), and subsequently linearly loaded until failure (Fmax [N]) at an angle of 135 degrees 3 mm below the incisal edge on the palatal side. Statistical tests were performed using the Kruskall-Wallis and Mann-Whitney U-Test. Results: During dynamic loading by TML, one early failure occurred in group C, CP, and CrP. Subsequent linear loading resulted in mean fracture load values [N] of C = 483 ± 219, CP = 536 ± 281, V = 908 ± 293, VP = 775 ± 333, Cr = 549 ± 258, CrP = 593 ± 259. The Kruskal-Wallis test showed significant differences of load capacity between groups (p 0.05). Mann-Whitney U-test revealed significantly lower maximum fracture load values of group C compared to group V (p = 0.014), after Bonferroni-Holm correction. Non-restorable root fracture was the most frequent type of failure. Conclusion: Endodontically treated maxillary central incisors with Class III defects directly restored with composite are as loadable as indirect crown restorations. Compared to full-coverage restorations, less invasive veneers appear to be more beneficial. Additional placement of glass-fiber posts shows no positive effect. Keywords: all-ceramic crown, Class III restorations, direct composite restorations, endodontically treated teeth, indirect restoration, post and core, veneers

Die Digitalisierung hält im zahnmedizinischen Alltag immer mehr Einzug und hat sich in vielen Bereichen bereits etabliert. Im Rahmen der Implantatplanung erleichtern Computerprogramme und digitale Technologien etliche Arbeitsabläufe und unterstützen den Implantologen auch während des operativen Eingriffs. Von der Industrie werden diverse Planungsprogramme zur Verfügung gestellt, welche die digital gewonnenen Daten erzeugen, zusammenführen und verarbeiten. Die Übertragung dieser virtuell ermittelten Daten auf die klinische Situation führt zu höherer Präzision, Sicherheit und Effizienz, was Behandlern und Patienten zu gleichen Teilen zugutekommt. In vielen, wenn auch nicht allen Indikationen lässt sich die digitale Planung schon implementieren. Obwohl die modernen Programme zahlreiche Prozessschritte automatisieren, bleibt die Planung an sich jedoch Sache des Implantologen und erfordert genauso viel Sorgfalt und Know-how wie zuvor. Keywords: Geführte Implantation, digitaler Workflow, virtuelle Implantatplanung, Planungssoftware, Bohrschablone