Alginate has been used in wound dressing and tissue engineering. In this study, our designed alginate sponge was examined for use as an optimal occlusion material. Alginate powder was mixed in double-distilled water (3.0% w/v), sterilized and lyophilized to become a sponge. Sixty Wistar rats were undergone the right mandibular incisor extraction and divided into 3 groups: the first group received an alginate sponge; the second received a gelatin sponge; and the third was un-treated. The mandibles were retrieved after 1, 2, 4 and 8 weeks and subjected for bleeding measurement, radiographic and histological analyses. Alginate and Gelatin groups showed significantly shorter bleeding time until hemostasis than control. In Alginate group, as well as the other groups, bone formation was observed from 2 weeks post operation. The extraction socket receiving alginate was finally filled with osteoblasts and bone, suggesting that alginate might be considered as a candidate for not only cartilage but bone generation.
Few studies have investigated the bone healing of the tooth extraction socket in type 2 diabetes. The purpose of this study was to evaluate the process of bone healing of mandibular incisor extraction sockets after inserting a titanium alloy screw in type 2 diabetes model rats. Rats were divided into type 2 diabetes model animal and a control group. Titanium alloy (Ti-6Al-4V) screws were placed into the mandibular incisor extraction sockets. At 3, 6, 9 and 12 weeks post-operation, biomechanical and histological observations were performed. As a result, removal torque strengths as biomechanical evaluation were not significant between the two groups. These study results demonstrated that type 2 diabetes has slightly differences on bone healing after tooth extraction without surrounding environment factor.
The purpose of this study was to evaluate the effect of direct pulp capping using recombinant human BMP-2 (rhBMP-2) on dentin regeneration. RhBMP-2 (1.0 mg/ml) was dissolved in alginate-based gel (AG). Cavities with the exposed pulp area were prepared of first molars in Wister rats. All cavities were divided into two groups: The exposed pulps were covered with AG contained rhBMP-2 (BMP group), and covered with AG alone (AG group). Then they were sealed with glass ionomer cement (Fuji IILC EM). The animals were sacrificed at 3 and 8 weeks after operation. In both groups, the covered materials were observed at 3 weeks after operation, while they had disappeared and the tertiary dentin formation was observed into the prepared cavity at 8 weeks after operation. Thickness of the tertiary dentin of BMP group was significantly higher than that of AG group (P<0.05). These results suggest that AG is effective scaffold and direct pulp capping using AG contains rhBMP-2 is capable of enhancing dentin regeneration.