title: Postoperative sensitivity in Class V composite restorations: Comparing soft start vs. constant curing modes of LED.
abstract: BACKGROUND
  One of the major disadvantages associated with using composites is polymerization shrinkage; stresses are generated at the margins, and if these stresses exceed the bond strength, microleakage occurs at the tooth restoration interface which causes ingress of cariogenic bacteria, post-operative sensitivity, and secondary caries. LED offers several curing modes: constant cure, ramped cure, and soft start cure. It is claimed that soft start polymerization mode produces less polymerization shrinkage and consequently less postoperative sensitivity.
  
  
  OBJECTIVE
  To compare the postoperative sensitivity in Class V composite restorations using soft start and constant LED curing modes.
  
  
  METHODS
  Using the appropriate burrs cavity was prepared and filled with composite Z 100(3M-ESPE) using a incremental technique. Each increment of 2 mm was cured either with soft start or constant cure. All patients were evaluated at day 2 for postoperative sensitivity.
  
  
  CONCLUSIONS
  Out of 124 restorations that were placed, only three restorations presented with postoperative sensitivity, each one being in mild, moderate, and severe categories, respectively. No relationship was seen between the sensitivity and tooth type. There was no statistically significant difference in postoperative sensitivity in either of the treatment modalities (constant or soft start).
  
  
  CONCLUSIONS
  We conclude that restorations placed with the soft start curing technique did not show significant changes in postoperative sensitivity when compared to the constant curing technique.
authors.affiliation: The Aga Khan University Hospital, Stadium Road, Karachi, Pakistan.
authors.forename: Fahad
authors.initials: F
authors.lastname: Umer
authors.forename: Frahan Raza
authors.initials: FR
authors.lastname: Khan