Immunoxpression of MMPs -9, -13 and TIMP-3 after Using Etch-and-rinse Adhesive

The aim of the present study was to determine the expression of MMP-9, MMP-13 and TIMP-3 after using the XP Bond ™ (Dentsply) dentin-bonding agent on 21 human teeth. Class I deep cavities were prepared and restored. After 01, 07, 14, 21, 30, 90 and 120 days, the teeth were extracted and processed for an immunohistochemical assessment (n=3). Immunohistochemical staining was performed using the monoclonal antibody anti-MMP-9, and polyclonal antibodies anti-MMP-13 and anti-TIMP-3. The immunoreactivity of metalloproteinases 9 and 13 was considered intense and moderate in the first storage intervals, before decreasing over time. In contrast, the immunoreactivity of TIMP-3 was considered absent in dentin and weak in pulp in the first time intervals, and completely absent in the subsequent intervals. MMP-9 expression in dentin and in pulp was prevalent in the dentinal tubules and odontoblastic layer, respectively. MMP-13 expression in dentin and in pulp was predominant in the pre-dentine region and odontoblastic layer, respectively. TIMP-3 expression was absent in dentin and predominantly located in the odontoblastic layer for pulp. In conclusion, the expression patterns of MMP-9, MMP-13 and TIMP-3 altered in the different time intervals studied. The increased expression of TIMP-3 in the first time intervals could suggest a synchronous response to the increased expression of MMPs in the same periods. The results confirmed the low performance of TIMP-3 in the physiological processes of the pulp-dentin complex for the conditions and materials tested herein.

In vitro antibacterial effect of fifth generation dentin bonding agent incorporated with nisin on Streptococcus mutans

Introduction Bacterial adherence to restorative materials such as composite resin is one of the aetiology of secondary caries. This study evaluated the antibacterial efficacy of fifth generation bonding agent (BA) modified with nisin, against Streptococcus mutans based on its growth, adherence and membrane integrity. Methods Adhesive eluents of the experimental bonding agents were obtained using 250 μl Brain Heart Infusion (BHI) broth and the groups were control (BA with 0% Nisin), bonding agent with 1 wt% (NBA 1) and 5 wt% nisin (NBA 5). To this, 10 μl S. mutans culture was added and incubated at 37 °C. Bacterial growth was estimated by changes in optical density using spectrophotometer every 20 min for 2 h. The results were statistically analysed using one way ANOVA followed by Tukey Post Hoc test. For adherence and membrane integrity test, 10 μl of BHI supplemented with 1% sucrose and 50 μl of bacterial suspension were inoculated onto the cured specimens, and incubated for 4 h. After rinsing, 1 ml of Live/Dead BacLight bacterial viability stain was added and incubated in the dark for 15 min and observed under confocal laser scanning microscope (CLSM) for intact (green/live) and damaged (red/dead) bacterial membranes. Results Mean optical density was significantly higher in control group at all time intervals with maximum value at 2 h (0.83 ± 0.008), while there was a concentration dependant reduction in bacterial growth with the NBA groups (0.50 ± 0.007). Correspondingly, the NBA groups showed higher amount of dead than live bacteria, while live bacteria were predominant in the control group. Significance Addition of an antibacterial agent nisin in dentin bonding agent may render the resin dentin interface more resistant to bacterial penetration, and adherence of cariogenic bacteria like S. mutans.

Pre-application of dentin bonding agent prevents discoloration caused by mineral trioxide aggregate

Background: To evaluate tooth discoloration by newly developed calcium silicate-based materials, and to examine the pre-application of dentin bonding agent (DBA) for preventing discoloration caused by mineral trioxide aggregate (MTA).Methods: The roots of 50 premolars were randomly divided into five groups (n=10) and cavities were prepared from resected root surfaces. MTA was placed in the cavities of teeth belonging to the ProRoot MTA (MTA) and RetroMTA (RMTA) groups. For teeth belonging to the ProRoot + DBA (MTA-B) and RetroMTA + DBA (RMTA-B) groups, DBA was first applied to the cavities prior to the addition of MTA. Teeth in the control group were restored with composite resin only (i.e., without MTA). After 12 weeks, MTA was removed from the MTA and RMTA groups and bleaching agents were applied for 3 additional weeks. Color assessments were recorded at baseline, and 1, 4, and 12 weeks, as well as after bleaching. A one-way ANOVA was performed to assess the differences between the two types of MTAs and color changes following DBA pre-application in each MTA group. A p-value of < 0.05 was considered indicative of statistical significance.Results: Following 12 weeks of MTA treatment, there was a significant difference between the discoloration in the MTA and RMTA groups (p < 0.05). However, no significant difference was observed between the RMTA and RMTA-B groups (p > 0.05). Following bleaching, the color changes (ΔE values) of the MTA group were not significantly different from those of the MTA-B group (p > 0.05). The difference of ΔE between the RMTA group after internal bleaching and the RMTA-B group was also not significant (p > 0.05).Conclusions: RetroMTA caused significantly less discoloration than ProRoot MTA. Pre-application of DBA reduced discoloration caused by ProRoot MTA. MTA discoloration was improved equally well between DBA pre-application and post-bleaching.

Pre-application of dentin bonding agent prevents discoloration caused by mineral trioxide aggregate

Background: To evaluate tooth discoloration by newly developed calcium silicate-based materials, and to examine the pre-application of dentin bonding agent (DBA) for preventing discoloration caused by mineral trioxide aggregate (MTA). Methods: The roots of 50 premolars were randomly divided into five groups (n=10) and cavities were prepared from resected root surfaces. MTA was placed in the cavities of teeth belonging to the ProRoot MTA (MTA) and RetroMTA (RMTA) groups. For teeth belonging to the ProRoot + DBA (MTA-B) and RetroMTA + DBA (RMTA-B) groups, DBA was first applied to the cavities prior to the addition of MTA. Teeth in the control group were restored with composite resin only (i.e., without MTA). After 12 weeks, MTA was removed from the MTA and RMTA groups and bleaching agents were applied for 3 additional weeks. Color assessments were recorded at baseline, and 1, 4, and 12 weeks, as well as after bleaching. A one-way ANOVA was performed to assess the differences between the two types of MTAs and color changes following DBA pre-application in each MTA group. A p-value of < 0.05 was considered indicative of statistical significance. Results: Following 12 weeks of MTA treatment, there was a significant difference between the discoloration in the MTA and RMTA groups ( p < 0.05). However, no significant difference was observed between the RMTA and RMTA-B groups ( p > 0.05). Following bleaching, the color changes (ΔE values) of the MTA group were not significantly different from those of the MTA-B group ( p > 0.05). The difference of ΔE between the RMTA group after internal bleaching and the RMTA-B group was also not significant ( p > 0.05). Conclusions: RetroMTA caused significantly less discoloration than ProRoot MTA. Pre-application of DBA reduced discoloration caused by ProRoot MTA. MTA discoloration was improved equally well between DBA pre-application and post-bleaching. Clinical Relevance: Tooth discoloration by mineral trioxide aggregate (MTA) limits its use in esthetic regions. The pre-application of dentin bonding agent (DBA) and the use of newly developed RetroMTA could help to prevent the discoloration caused by MTA.

Pre-application of dentin bonding agent prevents discoloration caused by mineral trioxide aggregate

Background: To evaluate tooth discoloration by newly developed calcium silicate-based materials, and to examine the pre-application of dentin bonding agent (DBA) for preventing discoloration caused by mineral trioxide aggregate (MTA).Methods: The roots of 50 premolars were randomly divided into five groups (n=10) and cavities were prepared from resected root surfaces. MTA was placed in the cavities of teeth belonging to the ProRoot MTA (MTA) and RetroMTA (RMTA) groups. For teeth belonging to the ProRoot + DBA (MTA-B) and RetroMTA + DBA (RMTA-B) groups, DBA was first applied to the cavities prior to the addition of MTA. Teeth in the control group were restored with composite resin only (i.e., without MTA). After 12 weeks, MTA was removed from the MTA and RMTA groups and bleaching agents were applied for 3 additional weeks. Color assessments were recorded at baseline, and 1, 4, and 12 weeks, as well as after bleaching. A one-way ANOVA was performed to assess the differences between the two types of MTAs and color changes following DBA pre-application in each MTA group. A p-value of < 0.05 was considered indicative of statistical significance.Results: Following 12 weeks of MTA treatment, there was a significant difference between the discoloration in the MTA and RMTA groups (p < 0.05). However, no significant difference was observed between the RMTA and RMTA-B groups (p > 0.05). Following bleaching, the color changes (ΔE values) of the MTA group were not significantly different from those of the MTA-B group (p > 0.05). The difference of ΔE between the RMTA group after internal bleaching and the RMTA-B group was also not significant (p > 0.05).Conclusions: RetroMTA caused significantly less discoloration than ProRoot MTA. Pre-application of DBA reduced discoloration caused by ProRoot MTA. MTA discoloration was improved equally well between DBA pre-application and post-bleaching.Clinical Relevance: Tooth discoloration by mineral trioxide aggregate (MTA) limits its use in esthetic regions. The pre-application of dentin bonding agent (DBA) and the use of newly developed RetroMTA could help to prevent the discoloration caused by MTA.