Massive evaluation of dental adhesives: “the battles of the bonds”

Objectives: There is a scarcity of papers dealing with large scale comparison of bond strength of dental adhesive systems (DAS). Moreover, results found in the literature show a very high discrepancy of results between studies. Our study was designed as a large scale experiment combining continuous dental education with data gathering allowing for evaluation of the use of adhesive technique amongst general practitioner (GP), Evaluation of the impact of directions for use and guidelines for handling, ranking of performance and technique sensitivity of DAS.
Methods: Each session (up to 40 attendees) is held in a specially equipped room for handling and testing of dental materials. Flat dentin surfaces obtained by polishing (Sic#800) are used to bond a composite cylinder (7mm² base surface) using a Teflon mold. Each sample is submitted to shear strength using a guillotine type device at a speed of 5mm/min. Data are submitted to various statistical analyses.
Results: 92 sessions have been held, more than 21,500 Shear Bond Strength (SBS) values obtained by more than 2,000 attendees with 100 different DAS. Mean SBS values, standard deviation for the adhesive systems tested is presented in Table 3. difference between the lowest (8.49 MPa) and highest (20.90 MPa) SBS is close to 250%!
Difference is highly significant (p<.001) between classes (Etch and Rinse and Self-etching) and their subclasses (p<.05)
Training has a significant impact (p<.05), last test SBS is 25% superior to first test SBS.
Conclusions: Battle of the bonds highlights the value of GP training in the field of DAS. Results are in good accordance with literature while providing new insights on seldom studied parameters like technique sensitivity. The results obtained could prove a valuable tool for informed choice of DAS by GP.