Libros

Purpose: To evaluate the fracture strength of endodontically treated molars filled with different composite resins, with or without fiber reinforcement. Materials and methods: A total of 60 intact mandibular molars were selected and endodontically treated. A standardized mesio-occlusal-distal cavity was prepared with cervical margins 1 mm above the cementoenamel junction and oral and buccal walls with 1.5-mm remaining thickness. Universal adhesive was used in all specimens in etch-and-rinse mode. Specimens were divided into four groups (n = 15 each) according to restoration technique: CSM group, adhesive overlay with hybrid ceramic (CeraSmart, GC); EXP group, direct composite restoration (Essentia U, GC) and everX Posterior (GC) as core material; ESU group, direct composite restoration (Essentia U); and EST group, direct composite restoration (Essentia U) reinforced with horizontal bidirectional glass fibers placed over the pulpal chamber floor (everStick-Net, GC). After 7 days of water storage, samples were loaded until fracture using a universal testing machine. The maximum breaking loads were recorded in Newtons (N), and statistical analysis was then conducted with two-way analysis of variance and post hoc Tukey test. Fragments were analyzed using scanning electron microscopy. Results: Mean fracture resistance was: CSM = 1,428.9 ± 316.90 N; EXP = 1,874.57 ± 299.47; ESU = 1,557.44 ± 355.65; and EST = 1,870.27 ± 145.11. CSM and EXP showed the highest strength values when compared to the other groups. The variable "fiber insertion" did not significantly alter the fracture resistance. Origins of the fractures were always located on the occlusal surface, mainly from the major contact loading area. Conclusion: The use of everX Posterior showed great improvement in fracture resistance, similar to cuspal coverage restoration. However, only short fiber-reinforced composite resins showed a favorable fracture pattern.

Aim: The aim of the present study was to demonstrate that fully digital workflows can provide predictable esthetic and functional outcomes. Materials and methods: The present clinical case report provides a step-by-step documentation of a full-mouth rehabilitation planned and performed with a fully digital approach utilizing an adhesive and no-prep method. After assessing the patient’s needs, a treatment plan was established that considered the patient’s functional and esthetic requests. The overlap of 2D images and 3D models and facial scans of the patient allowed the digital previsualization of the esthetic result by implementing the “copy-paste” approach to restore the maxillary anterior sextant. Conclusion: The final outcome was satisfactory in terms of esthetics, function, and soft tissue health. Palabras clave: tooth wear, dental occlusion, digital workflow, esthetics, digital wax-up, facial scan

In den letzten Jahren ist Zahnabnutzung zunehmend in den Fokus der Zahnmedizin gerückt, da ihre Prävalenz in der Bevölkerung immer weiter zunimmt. Gleichzeitig sind dank der Entwicklung der Adhäsivtechnik minimalinvasive Behandlungsansätze möglich geworden, mit denen sich abgenutzte Zähne langfristig erhalten und schützen lassen. Dieser Fallbericht zeigt die minimalinvasive Gesamtrehabilitation einer Patientin mit abgenutzten Zähnen. Die ästhetischen und funktionellen Ergebnisse wurden dabei mithilfe digitaler Werkzeuge, wie digitale Abformung, 3-D-Gesichtsscan, digitale Zahnformenbibliothek, transkutane elektrische Nervenstimulation (TENS), MRT und kinesiografische Analyse geplant, realisiert und im Behandlungsverlauf überwacht. Bei der Erhöhung der okklusalen Vertikaldimension kam statt der herkömmlichen Zentrikmethode ein myozentrisches Konzept zur Anwendung. Dieser Ansatz erlaubte die Beibehaltung der Klasse-I-Verzahnung, sodass eine invasivere kieferorthopädische oder kieferchirurgische Intervention vermieden wurde, was die Morbidität, Behandlungszeit und Kosten für die Patientin verringerte. Bei der 1-Jahres-Nachuntersuchung zeigte sich die Patientin gut an die neue Kieferrelation adaptiert, was belegt, dass der myozentrische Ansatz in geeigneten Fällen eine sinnvolle Alternative zur konventionellen Bestimmung der zentrischen Kondylenposition sein kann. Palabras clave: adhäsive Zahnmedizin, restaurative Zahnmedizin, myozentrische Relation, digitaler Workflow, additive Restauration, Gesamtrehabilitation

In recent years, tooth wear has been a growing concern in dentistry as it has become increasingly prevalent among the population. At the same time, the development of adhesive techniques has enabled minimally invasive treatment protocols, with the goal of preserving and protecting teeth for as long as possible. This clinical report presents the case of a full-mouth rehabilitation patient with tooth wear who was treated using minimally invasive techniques. Esthetic and functional outcomes were designed and monitored using digital tools such as digital impressions, 3D facial scans, a digital tooth library, transcutaneous electrical nerve stimulation (TENS), MRI, and kinesiographic (KS) analysis throughout the treatment. To increase the vertical dimension of occlusion, instead of using traditional centric relation (CR) methods, a myocentric relation (MCR) technique was employed. This approach allowed the clinician to maintain the occlusal Class I situation, avoiding more invasive orthodontic treatment or maxillofacial surgery and resulting in reduced morbidity, treatment time, and cost for the patient. At the 1-year follow-up, good patient adaptation was shown, suggesting that the MCR concept is a viable alternative to conventional CR methods in appropriate cases. Palabras clave: adhesive dentistry, restorative dentistry

Purpose: To evaluate the fracture strength of endodontically treated molars filled with different composite resins with vs without fiber reinforcement. Materials and Methods: A total of 60 intact mandibular molars were selected and endodontically treated. A standardized mesio-occlusal-distal cavity was prepared with cervical margins 1 mm above the cementoenamel junction and oral and buccal walls with 1.5-mm thickness. Universal adhesive was used in all specimens in etch-and-rinse mode. Specimens were divided into four groups (n = 15 each) according to restoration technique: group CSM = adhesive overlay with hybrid ceramic; group EXP = direct restoration with short fiber–reinforced composite; group ESU = direct restoration with nanohybrid composite; and group EST = direct restoration with nanohybrid composite reinforced with horizontal bidirectional glass fibers placed over the pulpal chamber floor. After 7 days of storage in water, samples were loaded until fracture using a universal testing machine. The maximum breaking loads were recorded in Newtons, and statistical analysis was then conducted with two-way ANOVA and post hoc Tukey test. Fragments were analyzed using scanning electron microscopy. Results: Mean fracture resistance values were: CSM = 1,428.91 ± 316.90 N; EXP = 1,874.57 ± 299.47 N; ESU = 1,557.44 ± 355.65 N; and EST = 1,870.27 ± 145.11 N. The CSM and EXP groups showed the highest strength values when compared to the other groups. The variable fiber insertion did not significantly alter the fracture resistance. The origin of the fracture was always located on the occlusal surface, mainly in the major contact loading area. Conclusion: The use of fiber-reinforced composite showed great improvement in fracture resistance, similar to a cuspal coverage restoration. However, only short fiber–reinforced composites showed a favorable fracture pattern. Int J Prosthodont 2023;36:603–611

Objectives: To review the dynamic analytical elements used in the functional assessment of the stomatognathic system, summarize the available scientific evidence, and consider interrelations with body posture and cognition. Method and materials: A thorough literature search was conducted using PubMed, the Cochrane Library database, and Google Scholar. Peer-reviewed articles and literature reviews provided up-to-date information addressing three topics: (a) the available knowledge and recent evidence on the relationship between the morphologic aspects of dental/craniofacial anatomy and oral function/dysfunction, (b) mandibular dynamics, considering mobility, functional activity, and existing methodologies of analysis, and (c) a possible correlation between the stomatognathic system, body posture, and cognition. Results: Modern dentistry may be regarded as a human adaptation strategy, helping to conserve healthy teeth for much longer without risking overall health. It is futile to treat patients using a mechanistic, sectorial approach that misrepresents patient behavior and requests, just as it is to affirm the absence of any structure-function relationships. However, it is also evident that there is a lack of general consensus on the precise functional assessment of the stomatognathic system, mostly due to the methodologic heterogeneity employed and the high risk of bias. Despite the abundant evidence produced with the aim of providing solid arguments to define dynamic models of functional assessment of the stomatognathic system, it is yet to become highly empirical, based as it is on operator experience in daily clinical practice. Conclusions: Further efforts from the scientific and clinical community, with the help of progress in technology, remain should this gap be filled and should substantial data on differences between pathologic and physiologic dynamic models of function be provided. Dentistry needs to employ – on a larger scale – objective, dynamic methods of analysis for the functional evaluation of the stomatognathic system, embracing concepts of “personalized medicine” and “interprofessional collaborations.” Palabras clave: cognition, kinesiography, mastication, neuroplasticity, oral function, posture

Objectives: To review the elements of static analysis in the functional assessment of the stomatognathic system, as promoted for more than a century by gnathologists, and summarize the available scientific evidence, including anthropologic observations. Method and materials: A thorough search was conducted using PubMed, the Cochrane Library database, and Google Scholar. From peer-reviewed articles and other scientific literature, up-to-date information addressing three topics was identified: (a) the anthropologic perspective with particular consideration for the role of progressive dental wear over time, (b) descriptions of gnathologic principles and evidence on their scientific validity, and (c) the methodologic inaccuracies introduced by seeking to correlate variables directly rather than allowing for causal inference. Results: For decades gnathology attempted to describe a structure-function correlation within the stomatognathic system by means of a model whose principles were static and mechanistic references. No scientific validation was ever achieved, placing clinical and research consensus out of reach. Conclusions: A historical perspective helps to place the fundamentals of gnathology into context: They were conceived to solve technical difficulties but were then assumed to be physiologic stereotypes. This misconception led to a decades-long promotion of mechanistic theories to describe oral function, but the evidence available today supports a more flexible and adaptable approach. Gnathologic arguments have been relegated to become exclusively of technical relevance in oral rehabilitation. Palabras clave: dental occlusion, gnathology, oral function, real-world data, temporomandibular disorder, tooth wear

Die Entwicklung der digitalen Technik verändert die Zahnmedizin in zunehmendem Maß. Weil die CAD/ CAM-Systeme und dentalen Werkstoffe kontinuierlich verbessert werden, sind Behandlungspläne für Rehabilitationen mittlerweile mit vollständig digitalen und nicht invasiven Ansätzen ausführbar. Digitale Ressourcen erhöhen die Genauigkeit bei der Vorhersage des ästhetischen und funktionellen Behandlungsergebnisses. Inzwischen finden sich immer mehr Patienten, die von starker Zahnabnutzung betroffen sind und von solchen Behandlungskonzepten profitieren können. Der vorliegende Beitrag bietet die Schritt- für-Schritt- Dokumentation einer Gesamtrehabilitation, die im digitalen Workflow mit additiven CAD/CAM-Restaurationen aus Komposit realisiert wurde. Zudem wird eine innovative Form der Funktionsanalyse gezeigt und diskutiert. Die Ausgangssituation wurde analysiert und mithilfe einer Snap-on-Apparatur mit der Rehabilitationsplanung verglichen. Nach der intraoralen Anpassung und Bestätigung wurde die definitive Versorgung realisiert. Die am Provisorium gewonnenen Erkenntnisse wurden hierfür digital an das Labor übermittelt.

Ein modernes Behandlungskonzept für Zahnabnutzung zielt darauf ab, die Progression frühzeitig aufzuhalten und idealerweise Präventivmaßnahmen einzuleiten. Falls es hierfür jedoch schon zu spät ist, kann mit interzeptiven Maßnahmen eingegriffen werden. Wichtig ist, die Notwendigkeit einer prothetischen Gesamtbehandlung zu vermeiden, da sie einen weiteren Hartsubstanzverlust mit entsprechenden biologischen Folgen bedingt. Da sich Anzeichen von Zahnabnutzung häufig bereits bei jungen Patienten finden, kann mithilfe der interzeptiven Behandlung mit Non-prep-Kompositrestaurationen die Progression des Hartsubstanzverlusts frühzeitig aufgehalten werden. Da die Zahnabnutzung normalerweise ein lebenslanges Problem ist, hat dieser Ansatz entscheidende zusätzliche Vorteile, da er erschwinglich und das Ergebnis relativ unproblematisch zu erhalten ist. Unter Wiederherstellungsoptionen für abgenutzte Zähne mit Komposit sind in letzter Zeit In-situ-Schablonentechniken (für Einzelzähne oder den ganzen Kiefer) wegen ihrer Effizienz und Einfachheit immer interessanter geworden. In diesem Artikel werden Modifikationen der ursprünglichen "Full-Molding-Technik" vorgestellt, mit deren Hilfe die meisten bisherigen Unzulänglichkeiten dieser Technik überwindbar sind. Dazu gehören die Verformung der Schablone, zeitraubende Überschussentfernung in den Approximalbereichen und unzureichende Präzision bei der Reproduktion der okklusalen Anatomie. Die 1- und 3-Jahres-Nachkontrollen beider hier gezeigten Fälle bestätigen die funktionelle und ästhetische Qualität der mit dieser Technik erreichten Resultate. Überlagerungen der kinesiografischen Analysen und 3-D-Abformungen der Situationen unmittelbar sowie ein Jahr nach der Behandlung für einen der beiden Fälle zeigen das Potenzial der Behandlungsmethode genauer auf.

The proliferation of digital technology is progressively changing dentistry. Thanks to continual improvements in CAD/CAM devices and dental materials, it is possible nowadays to carry out a treatment plan for oral rehabilitations with fully digital approaches and noninvasive concepts. The availability of digital resources allows clinicians to increase the predictability of enhanced esthetics and good functional results. There is an increasing number of patients today who are affected by excessive tooth wear and may benefit from these kinds of treatments. This article provides a step-by-step documentation of a full-mouth rehabilitation performed with a digital approach and additive CAD/CAM composite resin restorations. An innovative functional evaluation is also documented and discussed. The initial situation was assessed and compared with the rehabilitation project through a snap-on device. After the intraoral adjustment and validation, the final rehabilitation was performed according to the information obtained in the provisional phase and digitally transmitted to the laboratory.