Impact of different light curing mode on post-operative hypersensitivity after Class I composite restorations: A randomized clinical trial

The main challenges encountered when using direct composite resins are, polymerization shrinkage and shrinkage stress, the degree of polymerization conversion, and their limited depth of cure. To overcome these challenges soft start light curing mode is preferred nowadays. To evaluate the occurrence of post-operative hypersensitivity in Class I composite restorations comparing the soft-start with the constant light curing modes using 7 generation bonding agent. Twenty patients with each having contra lateral Class I occlusal caries lesions in molars were participated. Forty Class I cavity preparations were restored with 7th generation bonding agent 7generation bonding agent (Scotchbond Universal Adhesive (3M ESPE, St Paul, USA)) and 3M™ Filtek™ Bulk Fill Flowable Restorative (3M ESPE, St Paul, USA). For each patient, one restoration was cured with soft-start mode and the contralateral restoration was cured with constant curing modes using Light Emitting Diode (LED) curing light. POH was evaluated at day 1,2&7 post-treatment using Visual Analog Scale (VAS). Data were collected and analysed by ANOVA test. Statistically significant differences were observed between the two curing modes in occurrence of postoperative hypersensitivity (P<0.05). Statistical analysis revealed that incidence of POH were higher at day 1 and day 2 in constant light curing group as compared with soft start light curing group which were reduced at day 7 in both groups. Incidence of POH is seen less in soft start curing mode as compared with constant light curing mode. To reduce post-operative hypersensitivity soft start light curing mode should be used.