Introduction: The aim of this study was to evaluate the effect of chlorhexidine (CHX) application on immediate and two-month bond strength of a filled adhesive system.Methods: Forty eight non-carious human third molars without enamel of occlusal surface were randomly divided into two main groups according to CHX application: control and CHX. Each main group was further subdivided into 2 subgroups depending on storage time: immediate or two-month collagenase storage. In CHX groups, 2% CHX was applied for 30 s. Filled adhesive resin (PQ1) was applied on the etched dentin surfaces and cured in all experimental groups. Composite resin (Amelogen) was placed on the dentin surfaces and shear bond strength (SBS) was evaluated immediately and after two-month storage in collagenase solution. Failure modes were determined by stereomicroscope.Results: There was no significant difference in immediate SBS between groups (P>0.05). After two-month collagenase storage, although SBS was significantly reduced in control group (P<0.05), no significant reduction was observed in CHX group (P>0.05). SBS in CHX group was significantly higher than the control group (P<0.05).Conclusion: The use of CHX had no adverse effect on immediate bond strength of filled adhesive and could preserve the bond strength.

until the completion of healing process, which has its own complications in some critical fractures. To overcome this drawbacks bone adhesives are developed for the immobilization of fractured bones. Objective: In this in-vitro study we compared the bond strength obtained by immobilization of the bone fragments using plates and screw and new adhesive containing BTDMA monomer. Materials and Methods: In this experimental in-vitro trial, bone fractures were simulated in bovine’ s mandibular bone using an electrical saw. The bone fragments were randomly allocated in different groups and were immobilized with either plate and screws and adhesive containing 0, 10, 15% BTDMA. After 24 hours tensile bond strength was calculated using universal testing machine. One-way ANOVA and Tukey post hoe test were used for statistical analysis. Results: Mean (± standard deviation) of tensile bond strength of bone fixation using adhesive containing 15% (W/W) BTDMA monomer were 176. 0 (± 18. 89) N. These values were 149. 1 (± 23. 88) N for adhesive containing 10% BTDMA; 102 (± 17. 99) N for the base adhesive and 278. 9 (± 24. 12) N for the screw and plate technique. Significant differences were found regarding bond strength of bone fixation in 4 groups using bone adhesives or plate technique (P<0. 001). The highest bond strength was recorded for the plate group and the least was related to the base adhesive. Significant differences existed between all bone adhesives as declared by paired comparison (p<0. 05). Conclusion: Despite the lower bond strength in adhesive groups in comparison with screw and plate, with regards to possible complications of screw and plate technique, it seems bone adhesives containing BTDMA monomer can be used for bone fragment fixation. However, bond strength is just one of the numerous properties that an adhesive should have and more studies must be done on these kinds of adhesives.