Clinical Relevance Despite oxalate desensitizer showing a decrease in the rate of resin-dentin bond degradation over time, it compromised the baseline bond strength of etch-and-rinse adhesives to dentin. Further investigation regarding reliability of the combination of oxalate desensitizers and etch-and-rinse adhesives is required prior to implementation of this approach in the clinical routine. SUMMARY Potassium oxalate desensitizers were previously shown to effectively reduce the immediate permeability of resin-bonded dentin. The current study evaluated whether the effect of the combined application of oxalate with etch-and-rinse adhesives interferes with the durability of resin-dentin bonds when using etch-and-rinse adhesives. The bond strength of resin-bonded dentin specimens composed of two-step or three-step etch-and-rinse adhesives (Single Bond, One-Step and Scotchbond Multi-Purpose, respectively) was tested immediately (24 hours) and after 12 months of water storage. The adhesives were used either according to the manufacturers' instructions (control groups) or after treating acid-etched dentin with a potassium oxalate gel (BisBlock, BISCO, Inc). The treatment of dentin with potassium oxalate was shown to negatively affect the baseline bond strength of resin-bonded dentin specimens, regardless of the adhesive used ( p <0.05). After storage, the bond strength of the resin-bonded interfaces was significantly reduced for all the tested groups ( p <0.001). Nevertheless, the rate of decreasing bond strength was significantly lower for oxalate-treated specimens than for the controls ( p <0.05).

PURPOSE This article describes a technique that uses an occlusal index to restore teeth back to their original contour and anatomy with minimal finishing. A new type of ring-opening silorane composite reported to have less than 1% volumetric shrinkage was used in the restoration. For the silorane-based composite, there is no oxygen-inhibited layer to be polished away. The final composite layer is cured under pressure and further minimizes voids and gap formation. The technique can also be used on multiple posterior restorations under rubber dam isolation. Overall, if used properly, this technique helps the clinician produce superb anatomy and reduces time for posterior composite restorations.

SUMMARY This study evaluated the effect of 2% chlorhexidine digluconate (CHX) used as a therapeutic primer on the long-term bond strengths of two etch-and-rinse adhesives to normal (ND) and caries-affected (CAD) dentin. Forty extracted human molars with coronal carious lesions, surrounded by normal dentin, were selected for this study. The flat surfaces of two types of dentin (ND and CAD) were prepared with a water-cooled high-speed diamond disc, then acid-etched, rinsed and air-dried. In the control groups, the dentin was re-hydrated with distilled water, blot-dried and bonded with a three-step (Scotchbond Multi-Purpose-MP) or two-step (Single Bond 2-SB) etch-and-rinse adhesive. In the experimental groups, the dentin was re-hydrated with 2% CHX (60 seconds), blot-dried and bonded with the same adhesives. Resin composite build-ups were made. The specimens were prepared for microtensile bond testing in accordance with the non-trimming technique, then tested either immediately or after six-months storage in artificial saliva. The data were analyzed by ANOVA/Bonferroni tests (α=0.05). CHX did not affect the immediate bond strength to ND or CAD ( p >0.05). CHX treatment significantly lowered the loss of bond strength after six months as seen in the control bonds for ND ( p <0.05), but it did not alter the bond strength of CAD ( p >0.05). The application of MP on CHX-treated ND or CAD produced bonds that did not change over six months of storage. Clinical Relevance Attempts to use CHX adjunctively with conventional etch-and-rinse adhesives may play a clinically relevant role in the preservation of resin-dentin bonds.

Clinical Relevance Curing methods using lower irradiance levels were shown to be effective in reducing the rate of stress generation without compromising the conversion of the restorative composite. Higher C-factor was shown to enhance the stress rate and amount of stress generated. SUMMARY This study verified the influence of curing methods and light sources on contraction stress, stress rate and degree of conversion (DC) of a restorative composite at two C-factor (CF) levels. For the stress test, composite (0.84 mm thick) was applied between two glass rods 5-mm in diameter mounted in a servohydraulic testing machine. Stress rates were calculated as the change in stress vs time at each second. DC was measured by micro-FTIR. Five curing methods were tested at two C-factor levels (1.5 and 3.0): High Intensity LED (LED HI), Continuous Light (QTH CL), Medium Intensity LED (LED MI), Low Intensity LED (LED LI) and Pulse Delay (QTH PD). The results were analyzed by ANOVA and Tukey's test (α=0.05). For the stress test at CF 1.5, QTH PD presented lower values than LED HI, QTH CL and LED LI. At CF 3.0, no difference was observed among the curing methods. For all curing methods, stress values at CF 3.0 were statistically higher than those at CF 1.5. LED HI presented the highest maximum stress rate, followed by QTH CL, LED MI, LED LI and QTH PD for both C-factors. In the DC test, no difference was observed among the methods and between the C-factor levels.