The sonic activation system EDDY performed equally as well as PUI, and both methods were significantly superior compared with manual irrigation in straight root canals with regard to debris and smear layer removal.

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Vitamin C and vitamin E are known as important cellular antioxidants and are involved in several other non-antioxidant processes. Generally vitamin C and vitamin E are not synthesized by humans and therefore have to be applied by nutrition. The absence or deficiency of the vitamins can lead to several dysfunctions and even diseases (e.g. scurvy). The main interest in this study is that vitamin C and E are known to influence bone formation, e.g. vitamin C plays the key role in the synthesis of collagen, the major component of the extracellular bone matrix.In the present study we evaluate the effect of ascorbic acid (vitamin C) and α-tocopherol (vitamin E) on the proliferation and differentiation of primary bovine osteoblasts in vitro. Starting from standard growth medium we minimized the foetal calf serum to reduce their stimulatory effect on proliferation.An improved growth and an increased synthesis of the extracellular matrix proteins collagen type I, osteonectin and osteocalcin was observed while increasing the ascorbic acid concentration up to 200 μg/ml. Furthermore the effects of α-tocopherol on cell growth and cell differentiation were examined, whereby neither improved growth nor increased synthesis of the extracellular matrix proteins collagen type I, osteonectin and osteocalcin were detected.Further investigations are necessary to target at better supportive effect of vitamins on bone regeneration, and healing.

Donnermeyer D, Urban K, B€ urklein S, Sch€ afer E.Physico-chemical investigation of endodontic sealers exposed to simulated intracanal heat application: epoxy resins and zinc oxide-eugenols.

The aim of the study was to evaluate the adhesive forces for removing iatrogenically fractured endodontic nickel-titanium instruments using a modified tube technique with various pre-treatment agents in combination with a light-curing composite. 120 Nickel-Titanium-Mtwo instruments were cut at its parallel shaft and fixed in a vise with an overlap of 2 mm. The surfaces were treated with different agents: A) GC Metalprimer; B) Prime and Bond active; C) NaOCl (3%); D) citric acid (15%); E) phosphoric acid (37%) and group (F) was not pretreated (control). One end of a matching microtube, filled with light-curing composite, was placed over the instrument and a transmitting glass fiber inserted from the opposite side guaranteed polymerization. Pull-out tests (1 mm/min) were performed and failure load was measured digitally. Data were statistically analyzed using the ANOVA and Student–Newman–Keuls tests. Interfaces were subjected to SEM analysis. Prime and Bond active created significant higher pull-out values (mean 30.5 N) compared to all other groups (p < 0.001) and Metalprimer (18.5 N) was significantly superior to the untreated (12.6 N) and NaOCl (11.7 N) group (p < 0.05). No significant differences were obtained between the other groups (p > 0.05). Thus, adhesives improved bonding to fractured NiTi instruments.

Minerals and vitamins affect bone formation, genetics, nutrition, and hormones. Studies mainly focus on the elucidation of the metabolic pathways during biomineralization to get an idea of how to promote the process of biomineralization in vivo and in vitro. One qualified approach to reach this is to investigate the influence of different substances on the proliferation and differentiation of osteoblastic cell cultures in vitro. The aim of this study was to investigate the effects of different types of single B vitamins (B 6 , B 9 , and B 12) and a vitamin B complex (B 1 , B 2 , B 3 , B 5 , B 6 , B 9 , and B 12) on proliferation and differentiation of primary bovine osteoblastic cells in vitro. The proliferation of osteoblastic cells during the experiments was evaluated by cell number analysis while cultivating. The expression of marking proteins of the osteogenic differentiation was evaluated by immunohistochemistry. Previous experiments with seven different B vitamins in different concentrations revealed a positive effect on cell proliferation with increasing concentration caused by three B vitamins: pyridoxal (B 6), folic acid (B 9), and cobalamine (B 12). The use of vitamin B 6 , B 9 , and B 12 in different concentrations resulted in a significant increase of cell proliferation (p < 0.05). But neither the B vitamins nor the B vitamin complexes stimulated the expression of the typical bone cell proteins.

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