"When a doctor is doing a procedure that requires bonding, time matters." - Dr. Flucke DDS

The longer is takes you to place and set the composite, the greater the chance for contamination from saliva, blood, etc. Being able to place the material in one increment, then the ability to set it with total confidence of a full cure, results in better adhesive in dentistry. The better a composite fill sets, the better outcome for the patient.