Saratti, Carlo Massimo

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.

Während lange Zeit mechanische Theorien im Hinblick auf die Okklusion bestanden, stützt die verfügbare Evidenz heute eher das Modell einer dynamischen, anpassungsfähigen Okklusion. Der Beitrag beschreibt verschiedene aktuelle Konzepte, mit der Okklusion verbundene Prozesse, verschiedene Bisslagen und ihre Behandlung und anhand eines Patientenfalls die praktische Behandlung und Lösung von Funktionseinschränkungen und Kiefergelenkschmerzen. Keywords: Okklusion, Bruxismus, CMD, Parafunktion, Unterkieferkinematik

Zeitgemäße Ansätze für die Gesamtrehabilitation im abgenutzten Gebiss legen großen Wert auf die Verwendung minimalinvasiver und adhäsiver Techniken, insbesondere wenn jüngere Patienten oder interzeptive Fälle behandelt werden. Inzwischen gelten CAD/CAM-Komposite als günstige Materialoption für solche Behandlungen, da sie einen guten Ausgleich zwischen funktioneller Wiederherstellung und ästhetischer Verbesserung bieten. Sie fügen sich unauffällig in die natürliche Bezahnung ein, liefern neben ansprechenden ästhetischen Ergebnissen Restaurationen mit hoher Lebensdauer und nutzen die Vorteile der Adhäsivtechnik. Schließlich sind CAD/CAM-Komposite auch kostengünstiger als ihre keramischen Gegenstücke, was sie zu einer guten Wahl für umfangreiche Rehabilitationen macht. Der vorliegende Beitrag analysiert die Gründe für die Verwendung von CAD/CAM-Kompositen bei minimalinvasiven Gesamtrehabilitationen. Darüber hinaus werden Langzeitergebnisse bereits publizierter Fälle (8 Jahre bzw. 4 Jahre Nachbeobachtung) gezeigt und ein neuer Behandlungsfall, in dem ein volldigitaler Workflow genutzt wurde, Schritt für Schritt vorgestellt. CAD/CAM-Komposite bieten zahlreiche Vorteile, zu denen neben der effizienten und präzisen Verarbeitung auch die gute Reparierbarkeit sowie die Möglichkeit zählen, sehr dünne Schichten ohne Beeinträchtigung der Festigkeit zu fräsen. Für additive Restaurationen sind diese Komposite als Material der Wahl zu betrachten, da sie eine Präparation nahezu oder vollständig überflüssig machen. Allerdings können natürliche Unterschnitte an den abgenutzten Zähnen Probleme verursachen, weshalb die Restaurationen sorgfältig geplant werden müssen. Studiendaten belegen inzwischen, dass CAD/CAM-Komposite eine valide, leistungsfähige Option darstellen, um hervorragende funktionelle und ästhetische Resultate zu erreichen. Keywords: CAD/CAM-Komposit, digitale Zahnmedizin, restaurative Zahnmedizin, Zahnverschleiß

Modern management of the full-mouth rehabilitation of worn dentition emphasizes minimally invasive and adhesive techniques, especially in treating younger patients or interceptive cases. CAD/CAM composite resins have become valuable for such treatments due to their balance between functional restoration and esthetic enhancement. These materials blend seamlessly with the natural dentition, providing satisfactory esthetic results and enhancing restoration stability and longevity, exploiting the advantages of adhesive techniques. Moreover, CAD/CAM composite resins are more economical than their ceramic counterparts, making them a sustainable option for extensive rehabilitations. The present article analyzes the rationale for using CAD/CAM composite resin materials in full-mouth minimally invasive rehabilitations. It also presents the follow-up of two previously published cases (one up to 8 years and the other up to 4 years), and a new clinical case illustrating a step-by-step, fully digital workflow. CAD/CAM composite resins offer numerous advantages such as efficient and precise fabrication, the ability to be milled into very thin layers without compromising strength, and ease of reparability. They can be considered the elective material in additive approaches, minimizing or eliminating the need for tooth preparation. However, challenges may arise with natural undercuts in worn dentition, requiring careful planning. The results of studies on CAD/CAM composite resins nowadays show them to be a viable and effective option, offering the possibility of obtaining excellent functional and esthetic results. Keywords: CAD/CAM composite resin, digital dentistry, restorative dentistry, tooth wear

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. Keywords: 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. Keywords: 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. Keywords: 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.” Keywords: 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. Keywords: dental occlusion, gnathology, oral function, real-world data, temporomandibular disorder, tooth wear