Resin composites with antibacterial activity may be useful for preventing the secondary caries frequently seen around restorations. The purposes of this study were to investigate antibacterial light-activated dental resin composites incorporating each of two silver-supported antibacterial materials and evaluate their long-lasting inhibitory effect against Streptococcus mutans. Two types of silver-supported antibacterial materials, Novaron (N) and Amenitop (AM) were used. These antibacterial materials were incorporated into TEGDMA-UDMA-based light-activated resin composites, and the antibacterial activities and mechanical properties of these composites, and also the release of silver ions, were examined. Two silver-supported antibacterial materials inhibited the growth of the major oral pathogen S. mutans. The minimum inhibitory concentration in suspensions of N and AM against S. mutans was 40 microg/mL and 30 microg/mL, respectively. Composites incorporating 5 wt % (N-5) or more of Novaron and 7 wt % (AM-7) or more of Amenitop inhibited the growth of S. mutans after immersion in water for 6 months. There was no or extremely little release of silver ions from the N-5 and AM-7 composites after 1 day or after 6 months of immersion in water. No significant difference in either compressive or flexural strength was observed between the control and the N-5 composites after 1 day or after 6 months of storage in water. However, for the AM-5 composite, there was a significant difference in both strength parameters between the two immersion periods. These results indicate that a light-activated dental resin composite incorporating silver-supported antibacterial material such as Novaron may be useful clinically because of its long-lasting inhibitory effect against S. mutans and its favorable mechanical properties.

Resin composites with antibacterial activity may be useful to decrease the frequency of secondary caries around restorations. The purposes of this study were to investigate the antibacterial activity of light-activated resin composites incorporating one of three silver-containing materials and to evaluate their long-term inhibitory effect against Streptococcus mutans The three types of silver-containing materials, Novaron (N), Amenitop (AM), and AIS, were incorporated into TEGDMA-UDMA-based light-activated resin composites, and the antibacterial activities, mechanical properties and release of silver ions were examined. Minimum inhibitory concentrations in suspensions of N, AM, and AIS against S. mutans were 1.1, 1.2, and 23.0 mg/ml, respectively. Resin composites incorporating 5 wt% of Novaron (N-5) and 7 wt% of Amenitop (AM-7) inhibited the growth of S. mutans after immersion in water for 3 months, whereas the resin composite incorporating 10 wt% of AIS did not. No significant difference in either compressive or flexural strength was observed between the control and N-5 composites after 1 d and 3 months storage in water. However, for AM-5 composite, there was a significant difference in both strength parameters between the two immersion periods. There was no or extremely little release of silver ions from the N-5 and AM-5 composites after 1 d or 3 months immersion in water. These results indicated that a light-activated resin composite incorporating silver-containing materials such as Novaron may be clinically useful due to its long-term inhibitory effect against S. mutans and favorable mechanical properties.

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The solubility of resin luting cement remains unknown although the use of resin luting cement for routine cementation of restorations has increased. The purpose of this in-vitro study was to compare the solubilities of three resin cements currently in clinical use with three brands of conventional luting agents. The three resin luting cements, All-Bond C&B (AB, Bisco) Panavia 21 (P21, Kuraray), and Super-Bond C&B (SB, Sun-Medical), and the three conventional luting agents, Elite Cement 100 (EC, zinc phosphate cement, GC), HY-Bond Carbo-plus Cement (HCP, polycarboxylate cement, Shofu), and Fuji I (FI, glass-ionomer cement, GC) were used in this study. A modification of the ADA specification test was adopted to evaluate the solubilities of luting cements. The two types of media (distilled water and pH 4.0 lactic acid solution) in which specimens were stored for 30 days were prepared. The four luting cements, EC, FI, AB, and P21, were more soluble in lactic acid solution than in distilled water. Resin luting cements were markedly less soluble than conventional luting agents when placed in fresh lactic acid solution (0.001 mol/L) at pH 4.0 every 24 h over a 30-day period. The solubility rates of luting cements could be fitted to mathematical expressions which indicated that the solubilities increased linearly or logarithmically with immersion period. Fixed prosthodontic restorations cemented with resin luting cement may be capable of withstanding long-term clinical use compared with conventional luting agents.

Dental resin composites with antibacterial activity may be useful for preventing the secondary caries frequently seen around restorations. Three types of silver–supported antibacterial materials (Novaron, Amenitop and AIS) inhibited the growth of the major oral pathogen Streptococcus mutans. Minimum inhibitory amounts in suspensions of Novaron, Amenitop and AIS against S. mutans were 40, 30 and 400 μg/ml, respectively. These antibacterial materials were incorporated into TEGDMA–UDMA–based light–activated resin composite, and the antibacterial activities of these composites were examined. Composites incorporating 5 wt% (N–5) or more of Novaron and 7 wt% (AM–7) or more of Amenitop inhibited the growth of S. mutans, whereas composites incorporating up to 10 wt% of AIS did not. No significant difference in either compressive or flexural strength was observed between the control and N–5 composites after 1 day and 6 months of storage in water. However, for AM–5 composite, there was a significant difference in either strength parameter between the two immersion periods. There was no or extremely little release of silver ions from the N–5 and AM–5 composites after 1 day or 6 months of immersion in water. These results indicated that a light–activated resin composite incorporating silver–supported antibacterial material such as Novaron may be clinically useful due to its inhibitory effect against S. mutans and favorable mechanical properties.