Abstract Aim: The aim of the present systematic review of implant-supported maxillary overdentures was to assess the survival of implants, survival of maxillary overdentures and the condition of surrounding hard and soft tissues after a mean observation period of at least 1 year. Material and methods: MEDLINE (1950–August 2009), EMBASE (1966–August 2009) and CENTRAL (1800–August 2009) were searched to identify eligible studies. Two reviewers independently assessed the articles. Results: Out of 147 primarily selected articles, 31 studies fulfilled the inclusion criteria. A meta-analysis showed an implant survival rate (SR) of 98.2% per year in case of six implants and a bar anchorage. In case of four implants and a bar anchorage, the implant SR was 96.3% per person. In case of four implants and a ball anchorage, the implant SR was 95.2% per year. Conclusion: In all three treatment options, the SR of the implants is more than 95%. The studies included reveal that a maxillary overdenture supported by six dental implants, which are connected with a bar, is the most successful treatment regarding survival of both the implants and overdenture. Second in line is the treatment option with four implants and a bar. The treatment option with four or less implants and a ball attachment system is the least successful.

Objectives: Titanium implants with mean arithmetic roughnesses (Ra) of 1–2µm are associated with improved osseointegration and clinical outcome. However, the procedures used for producing a roughened surface usually change other parameters, such as spatial characteristic skewness and kurtosis, and sub-micrometre and nanoscale roughness. Studies are needed to explore the effect of different surface characteristics on osseointegration and clarify the relationship between Ra and osseointegration. This study aimed to investigate how titanium surfaces with different micrometer-scale roughnesses influenced proliferation, migration and differentiation of osteoblasts in vitro. Methods: Titanium replicas with surface roughnesses (Ra) of approximately 0µm, 1µm, 2µm and 4µm were produced. The surfaces have no significant sub-micrometre or nanoscale roughness and have similar skewness and kurtosis. MG-63 osteoblasts were cultured on the surfaces for up to 5 days and their behavior was investigated using time-lapse microscopy. The speed of cell migration was quantified using specialised software. Gene and protein expression were determined for alkaline phosphatase (ALP), osteocalcin and vascular-endothelial growth factor (VEGF). Results: Cell migration speeds were significantly lower on surfaces with Ra of about 4µm compared to those with lower Ra levels, with no differences between those with Ra in the range 0–2µm. Cell proliferation decreased gradually with increasing Ra. Gene expression of ALP, osteocalcin and VEGF was greater for the 1-µm and 2-µm Ra surfaces than the 0-µm and 4-µm surfaces. These findings were similar for protein expression. ALP and osteocalcin content in the conditioned media were significantly higher for cells grown on the 2-µm Ra surface compared to the 0-µm and 4-µm surfaces. The production of VEGF by cells on the 1-µm and 2-µm surfaces was significantly higher than that of the 0-µm surface. Cells grown on the 2-µm surface produced significantly more VEGF than those on the 4-µm surface. Conclusion: Surfaces with lower and higher roughnesses in this study seem to be suboptimal for osteoblasts. We suggest that decreased cell migration on surfaces with Ra 4µm might be associated with decreased osteoblast differentiation, probably through inhibition of cell-to-cell contact.

Morphologische Missbildungen wie zapfenförmige Seitenzähne sind häufige Anomalien, die restaurativ zu behandeln sind. Mit minimalinvasiven dentalchirurgischen Techniken, die zunehmend an Popularität in der ästhetischen Zahnmedizin gewinnen, ist eine idealästhetische Korrektur weitgehend oder gänzlich ohne Gewebsverlust möglich. Dieses Video zeigt die Rekonstruktion von zwei lateralen Schneidezähnen mit direktem Kompositaufbau gefolgt von einer sogenannten "natürlichen Beschichtung" mit Applikation von einzelnen Dentin- und Schmelzschichten, um die natürliche Zahnanatomie nachzuahmen. Alle Schritte zur Wiederherstellung des Zahns werden bis ins Detail erklärt, inklusive Farbauswahl, Anlegen des Kofferdamms, Klebeverfahren sowie Finishing und Polishing der Dentin- und Schmelzschichten. Durch die Einhaltung einer präzisen und sorgfältigen Operationstechnik erzielt man ein zuverlässiges Ergebnis mit einem völlig natürlich aussehenden Zahnersatz.