Die restaurative Therapie endodontisch behandelter Zähne mit glasfaserverstärkten Aufbaustiften

Die Restauration endodontisch behandelter Zähne stellt eine restaurative Herausforderung. Dabei ist das Ausmaß des koronalen Zahnhartsubstanzverlustes ein kritischer prognostischer Faktor. Postendodontische Restaurationen mit Aufbaustiften und plastischen Aufbauten sind indiziert, wenn eine oder keine Kavitätenwand verblieben ist. Im Rahmen der 11-Jahres-Nachuntersuchung einer randomisierten, kontrollierten Studie wurde die Versorgung mit Titanaufbaustiften der Rekonstruktion mit Glasfaseraufbaustiften gegenübergestellt. Beide Aufbaustiftsysteme erzielten vergleichbare Überlebensraten. Die adhäsive Befestigung der Aufbaustifte und die Einhaltung des Fassreifen-Designs begründen das Ergebnis. Versagensereignisse traten in beiden Versorgungsgruppen 8 Jahre nach Eingliederung der Restauration mit deutlicher Progredienz auf. Im Verlauf der Nachbeobachtung der randomisierten, kontrollierten Studie zu Glasfaser- und Titanaufbaustiften wurden Röntgenbilder der Versorgungen an zwei verschiedenen Zeitpunkten angefertigt. Es wurde eine digitale Methode zur Vermessung der Höhe des mesialen und distalen Limbus alveolaris entwickelt, um das marginale Knochenniveau im Verlauf einer mittleren Nachbeobachtungszeit von 54 (Glasfaseraufbaustifte) und 50 (Titanaufbaustifte) Monaten zu bewerten. Es zeigte sich, dass die Rigidität des Aufbaustiftmaterials keinen Einfluss auf die Veränderung des marginalen Knochenniveaus hat. Untersucht wurde im Design einer explorativen Analyse, welche Selbstaussagekraft Patienten zum Zustand ihrer postendodontischen Versorgung im Rahmen der Langzeit-Nachbeobachtung der randomisierten klinischen Studie aufweisen. Es zeigte sich, dass die Selbstaussage unter Anwendung eines Fragebogens ein vielversprechender, weiter zu untersuchender Ansatz ist, wenn Patienten mit postendodontischen Restaurationen nicht an einer klinischen Nachuntersuchung teilnehmen können. Entwickelt wurde nachfolgend eine Serie von In-vitro-Untersuchungen, um direkte und indirekte Kompositrestaurationen unter Berücksichtigung verschiedener Zahnhartsubstanzdefekte und der Insertion glasfaserverstärkter Aufbaustifte nach thermomechanischer dynamischer und anschließender linearer Belastung zu evaluieren. Dabei zeigte sich, dass endodontisch behandelte Frontzähne mit bis zu zwei Klasse-III-Kavitäten bei Versorgung mit direkten Komposit-Restaurationen adäquate Belastbarkeitswerte zeigen. Die Verwendung von Aufbaustiften hatte dabei keinen die Belastbarkeit steigernden Effekt. Bei stark ausgedehnten Frontzahndefekten mit vollständig fehlenden Kavitätenwänden war für direkte Restaurationen eine signifikant verringerte Belastbarkeit messbar. Die Anwendung eines Aufbaustiftes hatte dabei einen deutlich belastbarkeitssteigernden Effekt. Im Vergleich mit Kronenrestaurationen erzielen bei mesialen und distalen Klasse-III-Kavitäten endodontisch behandelte Frontzähne mit direkten Kompositrestaurationen gleiche Belastbarkeitswerte. Die Kombination von Kompositfüllungen mit Veneer-Restaurationen zeigte hohe Belastbarkeitswerte und stellte sich als vielversprechendes, weiter zu untersuchendes Konzept dar

Fracture Resistance of Zirconia Oral Implants In Vitro: A Systematic Review and Meta-Analysis

Various protocols are available to preclinically assess the fracture resistance of zirconia oral implants. The objective of the present review was to determine the impact of different treatments (dynamic loading, hydrothermal aging) and implant features (e.g., material, design or manufacturing) on the fracture resistance of zirconia implants. An electronic screening of two databases (MEDLINE/Pubmed, Embase) was performed. Investigations including > 5 screw-shaped implants providing information to calculate the bending moment at the time point of static loading to fracture were considered. Data was extracted and meta-analyses were conducted using multilevel mixed-effects generalized linear models (GLMs). The Šidák method was used to correct for multiple testing. The initial search resulted in 1864 articles, and finally 19 investigations loading 731 zirconia implants to fracture were analyzed. In general, fracture resistance was affected by the implant design (1-piece > 2-piece, p = 0.004), material (alumina-toughened zirconia/ATZ > yttria-stabilized tetragonal zirconia polycrystal/Y-TZP, p = 0.002) and abutment preparation (untouched > modified/grinded, p < 0.001). In case of 2-piece implants, the amount of dynamic loading cycles prior to static loading (p < 0.001) or anatomical crown supply (p < 0.001) negatively affected the outcome. No impact was found for hydrothermal aging. Heterogeneous findings of the present review highlight the importance of thoroughly and individually evaluating the fracture resistance of every zirconia implant system prior to market release

Survival rates and complication behaviour of tooth implant-supported, fixed dental prostheses: A systematic review and meta-analysis

Objective: To assess the survival and complication rates of tooth-implant supported fixed dental prostheses (T-I FDPs). Sources: An electronic search in MEDLINE/PubMed, Cochrane Library, and Embase was conducted using MeSH terms to identify randomised controlled trials (RCTs) or prospective studies with an observation period of at least 3 years, including at least 10 participants. Study selection: Included studies were qualitatively assessed. Survival rates of T-I FDPs and implants as well as technical and biological complications were obtained. Failure and complication rates were pooled by weighting each rate in inverse proportion to its variance. Data: A total of eight studies were considered for qualitative analysis; seven studies with a minimum follow-up of five years were included for quantitative analysis. Estimated survival rates of T-I FDPs were 90.8% (95% CI: 86.4-93.8%) after five years and 82.5% (95% CI: 74.7-88.0%) after 10 years. Implant survival estimates were 94.8% (90.9-97.0%) and 89.8% (82.7-99.4%) after 5 and 10 years, respectively. From a total of 185 T-I FDPs, 21 (11.4%) minor and 23 (12.4%) major biological complications were observed, whereas 23 (12.4%) minor and three (1.6%) major technical complications occurred. Conclusions: Due to the lack of well-designed studies exceeding a 10-year follow-up, prognosis for the long -term can hardly be given. Considering the inclusion criteria of this systematic review, T-I FDP-supported fixed dental prostheses show acceptable survival rates after five and 10 years. Rigidly constructed T-I FDPs should be preferred. With regard to the available data, these conclusions are valid only for three- to four-unit T-I FDPs. Clinical significance: Tooth-implant supported fixed dental prostheses are a recommendable treatment option in partial dentition. Based on the current literature, they should be rigidly constructed with a maximum number of four units

Direct restoration of endodontically treated maxillary central incisors: post or no post at all?

ObjectivesThe aim of this ex-vivo study was to evaluate the impact of cavity size and glass-fiber post (GFP) placement on the load capability of endodontically treated maxillary incisors directly restored with resin composite.Materials and methodsNinety-six extracted human maxillary central incisors were endodontically treated and distributed to four groups (n=24): access cavity (A), access cavity and uni-proximal class III cavity (U), access cavity and bi-proximal class III cavity (B), and decoronated tooth (D). Specimens were restored with resin composite, and 12 specimen of each group received an adhesively placed glass-fiber post (P). Prior to linear loading, specimens were exposed to thermo-mechanical loading (TCML). Statistical analysis was performed using log-rank test after TCML, Kruskall-Wallis and Mann-Whitney U test to compare load capabilities (F-max).ResultsSignificantly more failures occurred in group D for specimens without GFP during TCML (p=0.001). F-max (mean (SD) in N was (A) 513 (124), (AP) 554 (201), (U) 438 (171), (UP) 537 (232) (B) 483 (219), (BP) 536 (281), D 143 (181), and DP 500 (331), and differed significantly among groups (p=0.003). Pair-wise comparison revealed lower F-max values for group D compared to all other groups (p<0.034) except group DP.ConclusionsEndodontically treated maxillary central incisors with cavity sizes up to bi-proximal class III may be successfully directly restored with resin composite. Post placement shows no additional effect except for decoronated endodontically treated incisors.Clinical relevanceEndodontically treated incisors with access cavities to class III cavities can be successfully restored with resin composite. Post placement for decoronated ETT is recommended

Long-term survival of adhesively post-endodontically restored teeth.

INTRODUCTION The objective of this prospective clinical study was to investigate survival for endodontically treated teethrestored with adhesively luted prefabricated rather dentin-like or rigid posts. METHODS Data were recorded for glass-fiber posts (GFP II) and compared to historical controls evaluating glass-fiber (GFP I) and titanium posts (TP) for 128 patients. Three groups were defined based on type of post system used: #1 GFP I (n=41), #2 GFP II (n=41) and #3 TP (n=46). Posts were adhesively luted with self-adhesive resin, adhesive composite-core build-ups were performed and all teeth were restored with full-coverage restorations. Primary endpoint was restoration survival at recall. Clinical and radiographic outcome was assessed after 6, 12, 24 and up to 178 months. Data were analysed by Kaplan-Meier log-rank test and Cox-regression analysis. RESULTS After up to 178 months of observation 26 restorations failed (GFP I: 10, GFP II: 9, TP: 7) and 49 (GFP I: 18, GFP II: 12, TP: 19) were in situ. Cumulative survival probabilities were 57.1% for GFP I, 56.5% for GFP II and 71.8% for TP. In bivariate Cox regression the factors 'tooth type' and 'grade of abrasion' were significantly associated with failure. In multivariate Cox regression, none of the investigated factors were significantly associated with failure. The post system had no significant impact on tooth survival (P > 0.05). CONCLUSIONS Comparing glass-fiber and titanium posts the post system had no impact on tooth survival after up to 15 years. This study indicates that effect size of post material on survival is low