Treatment of infected root canals with 4-META/MMA-TBB resin

This review paper describes the various applications of 4-methacryloxyethyl trimellitate anhydride/methyl methacrylate-tri-n-butyl borane (4-META/MMA-TBB) and reviews research studies on the treatment of infected root canals using 4-META/MMA-TBB resin. 4-META/MMA-TBB resin exhibits good biocompatibility, polymerisation, and adhesiveness to dentine. As a result, it has improved the previously low success rates of root-end sealing, root canal filling, and perforation sealing in difficult cases. Root-end sealing of resected surfaces using 4-META/MMA-TBB during apicoectomy and intentional replantation prevents leakage from root canal and root resorption. 4-META/MMA-TBB can offer sealing for root canals with opened root apex in which pressure could not be applied during root canal filling. In this paper we will discuss clinical cases related to the application of this resin and the benefits of 4-META/MMA-TBB resin

Antibacterial and cytotoxic effects of photoexcited Au clusters via blue high-power or white low-power light emitting diode irradiation

The development of photosensitizers and light sources has enabled the use of antimicrobial photodynamic therapy (aPDT) in various dental therapies. In the present study, we compared the antibacterial and cytotoxic effects of Au clusters photoexcited by blue and white LED irradiation. We fabricated novel photosensitizers, captopril-protected gold (Capt-Au) clusters and lysozyme-stabilized gold (Lyz-Au) clusters, for aPDT. Au clusters were then photoexcited by two kinds of light sources, blue high-power and white low-power light-emitting diodes (LEDs). Since white LED contains a wide spectrum of light (400–750 nm), white LED would be relevant for aPDT even if using a low-power source. The turbidity and viability of Streptococcus mutans were assessed following application of Capt-Au clusters (500 μg/mL) or Lyz-Au clusters (1,000 μg/mL) photoexcited by a blue high-power LED (1,000 mW/cm2) or white low-power LED (80 mW/cm2). In addition, the cytotoxicity of Au clusters and LED irradiation was evaluated in NIH3T3 and MC3T3-E1 cells. Au clusters photoexcited by the white low-power LED equally decreased the turbidity and viability of S. mutans compared with blue high-power LED. However, Au clusters photoexcited by white LED irradiation caused decreased cytotoxicity in mammalian cells compared with those photoexcited by blue LED irradiation. In conclusion, white LEDs possess biosafe properties for aPDT using Au clusters

Bone Augmentation by Implantation of an FGF2-loaded Collagen Gel-sponge Composite Scaffold

Fibroblast growth factor-2 (FGF2) plays a critical role in osteoblastic cell proliferation. Collagen gel-sponge composite is an effective scaffold for tissue engineering. The purpose of this study was to evaluate whether addition of FGF2 to collagen gel-sponge composite promotes bone augmentation in rats.The rats were assigned to groups designated F0, F3 and F15, and received implantation of collagen gel-sponge composite containing 0, 3 and 15 µg FGF2, respectively, into a cranial bone defect. Specimens were prepared 1, 2 and 5 weeks after surgery for histologic and histomorphometric analysis.Newly formed bone area in groups F3 and F15 was significantly greater than that in group F0 at all stages. These results suggest that FGF2-loaded collagen gel-sponge composite scaffold stimulates bone augmentation and might provide a more effective bone engineering approach

Fabrication and cell behavior assessment of antibacterial micro/nano-patterned chitosan films

The surface of biomaterials with a fine micro/nano-pattern reportedly affects cell behavior. Chitosan was previously shown to exhibit antibacterial properties and thus here we evaluated the cellular response and antibacterial activity of chitosan micro/nano patterns prepared by the imprint method. We fabricated micro/nano patterns with different sizes and shapes of pillars, grooves, and holes. The chitosan pattern films exhibited antibacterial activity towards Streptococcus mutans. In addition, we observed mammalian cells adhering to and spreading on the chitosan pattern, and found that the orientation of the cells was controlled by the shape of the pattern

Ectopic Bone Induction by BMP-loaded Collagen Scaffold and Bone Marrow Stromal Cell Sheet

We combined the use of bone morphogenetic protein-2(BMP-2)-loaded collagen scaffold and cultured bone marrow stromal cell (BMSC) sheet in order for developing new bone tissue engineering.Rat BMSC sheets were generated in the presence of dexamethasone, β-glycerophosphate and ascorbic acid. Four types of the grafts were implanted in the intermuscular region of rat femurs: control group, collagen sponge; cell group, BMSC sheet in collagen sponge; BMP group, BMP-2-loaded collagen sponge; and BMP-cell group, BMSC sheet in BMP-2-loaded collagen sponge. Four weeks after surgery, histological and histomorphometric analysis were performed.The BMP-cell group demonstrated abundant new bone formation compared to all the other groups (p<0.05) and marked resorption of the implanted collagen when compared to the control and cell groups (p<0.05).The combination of BMP-2-loaded collagen sponge and BMSC sheet appeared to successfully promote an osteoinduction

The effects of collagen hydrogel implantation in buccal dehiscence defects in beagles.

Type I collagen hydrogel treated by an ascorbate-copper ion crosslinking system is highly biocompatible and highly degradable in the body. The purpose of this study was to examine the effect of collagen hydrogel on periodontal wound healing in beagles. Sixty-four periodontal dehiscence type defects were created on the buccal roots of four beagles. Subsequently, collagen hydrogel was implanted in each defect in the experimental group and sutured, and, in the control group, the defect was sutured without any application of collagen hydrogel. The percentage of the length of new bone and new cementum in the experimental group was significantly greater than that in the control group at weeks 4 (p<0.01) and 8 (p<0.05). Significantly more junctional epithelium was observed in the control group than in the experimental group at weeks 2 (p<0.01) and 4 (p<0.05). These findings thus indicate that periodontal regeneration was stimulated by collagen hydrogel implantation in beagles

Application of collagen hydrogel/sponge scaffold facilitates periodontal wound healing in class II furcation defects in beagle dogs

Background and Objective:  A three-dimensional scaffold may play an important role in periodontal tissue engineering. We prepared bio-safe collagen hydrogel, which exhibits properties similar to those of native extracellular matrix. The aim of this study was to examine the effect of implantation of collagen hydrogel/sponge scaffold on periodontal wound healing in class II furcation defects in dogs. Material and Methods:  The collagen hydrogel/sponge scaffold was prepared by injecting collagen hydrogel, cross-linked to the ascorbate-copper ion system, into a collagen sponge. Class II furcation defects (of 5 mm depth and 3 mm width) were surgically created in beagle dogs. The exposed root surface was planed and demineralized with EDTA. In the experimental group, the defect was filled with collagen hydrogel/sponge scaffold. In the control group, no implantation was performed. Histometric parameters were evaluated 2 and 4 wk after surgery. Results:  At 2 wk, the collagen hydrogel/sponge scaffold displayed high biocompatibility and biodegradability with numerous cells infiltrating the scaffold. In the experimental group, reconstruction of alveolar bone and cementum was frequently observed 4 wk after surgery. Periodontal ligament tissue was also re-established between alveolar bone and cementum. Volumes of new bone, new cementum and new periodontal ligament were significantly greater in the experimental group than in the control group. In addition, epithelial down-growth was suppressed by application of collagen hydrogel. Conclusion:  The collagen hydrogel/sponge scaffold possessed high tissue compatibility and degradability. Implantation of the scaffold facilitated periodontal wound healing in class II furcation defects in beagle dogs