Junkyu Park1, Juhea Chang, Jack Ferracane, In Bog Lee. 1. Department of Conservative Dentistry and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, South Korea.
Abstract
OBJECTIVES: The purpose of this study was to determine the effect of different layering techniques on cuspal deflection in direct composite restorations. METHODS: Aluminum blocks were used to prepare MOD cavities divided into three groups. Each cavity was restored with composite using three different filling techniques. Group 1 was filled in bulk, group 2 was restored by a horizontal increment technique, and group 3 by an oblique increment technique. Cuspal deflection was measured with LVDT probes and compared among groups using ANOVA and Scheffe's post hoc test (alpha = 0.05). RESULTS: The cuspal deflections in groups 1-3 were 21.6+/-0.90 microm, 19.3+/-0.73 microm and 18.4+/-0.63 microm, respectively. The bulk filling technique yielded significantly more cuspal deflection than the incremental filling techniques, while there was no significant difference between the horizontal and oblique increment methods. SIGNIFICANCE: Cuspal deflection resulting from polymerization shrinkage can be reduced by incremental filling techniques to obtain optimal outcomes in clinical situations.
OBJECTIVES: The purpose of this study was to determine the effect of different layering techniques on cuspal deflection in direct composite restorations. METHODS:Aluminum blocks were used to prepare MOD cavities divided into three groups. Each cavity was restored with composite using three different filling techniques. Group 1 was filled in bulk, group 2 was restored by a horizontal increment technique, and group 3 by an oblique increment technique. Cuspal deflection was measured with LVDT probes and compared among groups using ANOVA and Scheffe's post hoc test (alpha = 0.05). RESULTS: The cuspal deflections in groups 1-3 were 21.6+/-0.90 microm, 19.3+/-0.73 microm and 18.4+/-0.63 microm, respectively. The bulk filling technique yielded significantly more cuspal deflection than the incremental filling techniques, while there was no significant difference between the horizontal and oblique increment methods. SIGNIFICANCE: Cuspal deflection resulting from polymerization shrinkage can be reduced by incremental filling techniques to obtain optimal outcomes in clinical situations.