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Dentin specimens from 46 extracted human molar teeth were used in a matched-pair design examining the factors of temperature/humidity on shear bond strength of a dentinal adhesive to dentin. For one tooth-half, all procedures using restorative materials were accomplished in a controlled temperature and humidity chamber (humidity 95.0 +/- 2.0%, temperature 37.0 +/- 0.3 degrees C). For the other matched tooth-half all procedures were performed at ambient room conditions (humidity 52%, temperature 23.3 degrees C/74 degrees F). Oil-free air and water were used in all restorative procedures. Application of Scotchbond Multi-Purpose Adhesive System was followed by placement of Z100 Restorative Resin, and thermocycling 1000 cycles from 5 to 55 degrees C. Each matched specimen was tested 24 hours later in an Instron Testing Machine. A paired t-test was performed for comparison of bond strength set values, since they were obtained from matching halves of the same teeth. Paired t-test comparison showed that the average humidity/temperature chamber mean of 7.14 +/- 3.12 MPa was significantly less than the ambient conditions mean of 14.29 +/- 5.07 (P = 0.0000). Bond strength testing under simulated oral conditions may produce significantly different findings than customary bench-top laboratory experiments.

This study compared the shear bond strength to enamel of Scotchbond Multi-Purpose Dental Adhesive System's bonding resin following etching of enamel with 10% maleic, 1.6% oxalic, 10% phosphoric, and 35% phosphoric acids for 15, 30, and 60 seconds. Three hundred and sixty human molar teeth were used to create 12 groups of 30 enamel specimens per group (n = 30). Flattened enamel surfaces were treated with the different etchants for the time periods indicated, the surfaces primed, and adhesive resin applied according to the manufacturer's recommendations. The specimens were completed with Silux Plus resin and subjected to 1000 thermocycles (5-55 degrees C) followed by shear stress in an Instron Testing Machine to failure within a 24-hour period. A two-way ANOVA revealed significant differences for shear bond strength values by type of etchant (10% phosphoric, 35% phosphoric > 10% maleic > 1.6% oxalic acid) (P < 0.005) and by length of application time (P < 0.005). The interaction term for these two treatments was statistically significant (P < 0.005).

This study compared the microleakage characteristics of four dentinal adhesives against Scotchbond 2 as a control and discusses the results in light of recently reported bond strengths for these same materials. Dentin specimens from 100 caries-free extracted human molar teeth were used in a matched pair design. In each of the four test materials, 25 tooth sides were treated along with the matching control, subjected to 500 thermocycles (5 to 55 degrees C), followed by AGNO3 dye penetration, specimen sectioning, and evaluation by low-power stereomicroscopy. Mean microleakage values were as follows (microns): Scotchbond Multipurpose, 498.0; All-Bond 2, 530.8; Syntac, 748.0; X-R Bond, 844.9; and the Scotchbond 2 control (a composite score created by averaging four sets of 25 tooth sides), 1095.2. Paired t-tests showed that Scotchbond Multipurpose, Syntac, and All-Bond 2 had significantly lower microleakage than the control (P=0.0001); however, X-R Bond had no significant difference from the control (=0.4634).

This study compared the shear bond strengths on dentine of five dentine adhesives against Scotchbond 2 as a control. Dentine specimens from 225 extracted human permanent molar teeth were used in a matched-pair design, such that 45 tooth sides were treated along with the matching control for each of the five test materials. Shear bond strength testing was conducted 24 h after the completion of each specimen. Results showed that mean force (MPa) for the materials were: XR Bond, 17.1 +/- 5.1; Scotchbond Multi-Purpose, 15.9 +/- 6.5; Syntac, 13.5 +/- 8.6; All-Bond 2, 6.2 +/- 4.1; Scotchbond 2 (control composite score), 4.9 +/- 3.0; Denthesive, 3.4 +/- 1.7. Matched pair t-test comparisons with Scotchbond 2 control were: XR Bond, P = 0.0005; Scotchbond Multi-Purpose, P = 0.0005; Syntac, P = 0.0005; All-Bond 2, P = 0.0368; Denthesive, P = 0.005. Analysis of variance determined a statistically significant difference (P = 0.05) between the means of the bond strengths, which fell into four groups: Group A, XR Bond and Scotchbond Multi-Purpose; Group B, Syntac; Group C, All-Bond 2 and Scotchbond 2; Group D, Scotchbond 2 and Denthesive. In Group C, there was no significant difference between Scotchbond 2 and All-Bond 2. In Group D there was no significant difference between Scotchbond 2 and Denthesive, however, there was significant difference between All-Bond 2 and Denthesive. It was concluded that XR Bond and Scotchbond Multi-Purpose had significantly better shear bond strength than the other dentine adhesives.