Introduction: Provision of proper bond strength for tooth-colored restorations is very important in the restoration of primary teeth. The aim of this study was to compare shear bond strengths of Clearfil SE two-step self-etch, Palfique one-step self-etch and G-Premio universal BONDING agents. Materials & Methods: A total of 45 intact extracted primary canine teeth were collected for the purpose of this in vitro study and randomly divided into three groups (n = 15). The buccal surfaces of the teeth were prepared with 600-grit silicon carbide discs. The adhesive was applied by a micro-brush to the surface of the teeth according to manufacturer’ s instructions; Z350XT composite resin was placed using a plastic mold measuring 2 mm in diameter and 2. 5 mm in length and then light-cured. Finally, the shear bond strength was measured using a universal testing machine. Data were analyzed with ANOVA and Tukey test, using SPSS 21 (α = 0. 05). Results: The highest shear bond strength was recorded in G-Premio bond with a mean of 20. 60 MPa. Clearfil SE Bond ranked the second with a mean of 18. 62 MPa. Palfique Bond exhibited the lowest bond strength (14. 64 MPa). There was a significant difference between G-Premio Bond and Palfique Bond (p value < 0. 001) and between SE Bond and Palfique Bond (p value = 0. 01). However, there was no significant difference between G-Premio Bond and SE Bond (p value = 0. 29). Conclusion: Since 17 MPa has been proposed as the critical value needed to withstand polymerization shrinkage, both G-Premio Bond and Clear fil SE Bond have adequate strength for use in primary teeth. Palfique Bond exhibited lower bond strength compared to the two other BONDING agents inn primary teeth. Due to the fewer steps of G-Premio Bond in the self-etch mode, use of this BONDING agent appears to be logical for the restoration of primary teeth.

Background and Aim: The purpose of this study was to compare the shear bond strength of three BONDING agents known as Excite, Prime & bond NT and Clearjil SE Bond.Materials and Methods: Sixty premolar teeth were randomly divided into two groups. The buccal surfaces of 30 teeth in group 1 were cut by trimmer to expose the DENTIN in the coronal portion and those of the teeth in group 2 were cut to expose the DENTIN in the root portion. Mounted samples in acryl resin were randomly divided into three groups. The Excite BONDING agent was used in groups (1-1) and (2-1); Prime & bond NT in groups (1-2) and (2-2) and finally the Clearfil SE Bond in groups (1-3) and (2-3). Then, composite Z100 was used to restore all cavities.Results: In coronal sections and in comparison between groups (1-1) & (1-2) there was no significant statistical difference. In radicular sections there was significant difference between (2-1) & (2-2) groups, (2-1) & (2-3) groups and (2-3) & (2-2) groups.Conclusion: Attachment to DENTIN either in coronal or in radicular sections had more bond strength when we use self etch BONDING agent compared to total etch BONDING agent. Also the type of BONDING agent affects the bond strength in the root, but has little effect in the crown. BONDING agent with ethanol solvent has a greater effect than BONDING agent with acetone agent.

Background and Aim: An important requirement for a DENTIN BONDING agent is biological compatibility. Since DENTIN BONDING agents are placed in cavity preparations with subgingival extensions, with direct contact to gingival and mucosal tissues, tissue response to these materials must be investigated. The aim of this study was to examine the cytotoxicity of AdheSE, a self etching adhesive, on human gingival fibroblasts.Materials and Methods: In this experimental in vitro study, primary human gingival fibroblasts were exposed to different dilutions of primer & bond of AdheSE (Vivadent, Liechtenstein). The toxicity of the primer was tested in 30 seconds, 300 seconds and 24 hours. The cytotoxicity of the bond was analyzed in uncured mode after 20 seconds, 5 minutes and 24 hours. In cured mode, tested materials were analyzed after 24 and 48 hours. Cytotoxic effects were evaluated using MTT, cell counting and DNA condensation assays. Data were analyzed by two way repeated measure ANOVA with p<0.05 as the level of significance.Results: MTT Assay revealed that uncured AdheSE Bond was toxic only in 10-1 dilution and the difference with control group was significant (P<0.05). By increasing the time to 300sec. and 24h, dilutions of 10-2 and 10-4 were the most cytotoxic respectively. Cytotoxicity of uncured primer after 30 sec. and 300 sec. began from 10-2 and after 24h began from 10-2 and reached to 10-1. AdheSE in cured mode showed significant difference with control group in 1:2 (P<0.001), 1:4 & 1:6 (P<0.01) dilutions. In cell counting assay only the 1:2 dilution was significantly more toxic than control group. Apoptosis (a morphological and biochemical distinct form of cell death that regulates cell turnover) comprised in less than 5% of total death in both cured and uncured adhesives.Conclusions: Based on the results of this study, by increasing the exposure time, smaller amounts of BONDING could be cytotoxic. Cytotoxicity was related to material, dilution, time of exposure and curing. It would be necessary to identify the toxic ingredients of this adhesive and replace them by more biocompatible components.