Surface Roughness of Composite Restorations After Eight Months Functioning In-vivo

Objectives: The objective of this study was to compare surface roughness of the occlusal restorations after eight months in full function in human teeth made of Extra Low Shrinkage ® and two other composite materials.

Methods: Adhesive type occlusal cavities were prepared in six intact third molars in patients 20-25 years old, eight months before their extraction due to orthodontic indication. All teeth were in complete physiological function to the antagonists. Following total acid etch technique, three adhesive system/composite combinations were applied, each in two teeth: ELS® + James 2 (Saremco, Switzerland), TetricCeram + Excite (Vivadent, Liechtenstein), Point 4 + OptiBond SoloPlus (Kerr, Italy). Restorations were placed using “oblique incremental technique”. Each layer was light cured for 40 sec with the same curing device (Astralis 7, Vivadent, Liechtenstein). Final modeling and polishing was conducted using tungsten-carbide finishing/ polishing kit (Kerr, USA), and silicone polishers (Swiss Dental Instruments, Heerbrurgg, Switzerland). Following extraction teeth were stored in deionized water at 370C, not longer than for 7 days before optical roughness measurement was conducted. Difference between intensities of the emitted and reflected narrow range wavelength light (LED) defines the surface roughness. For each sample roughness of enamel and composite restoration was measured at 21 spots, respectively. Statistical parameters were compared for each tooth sample between enamel and restoration, and between composite materials.

Results: Mean value of the enamel surface roughness was 0.3742 (SD=0.05716), for ELS® it was 0.3484 (0.02746), and for TetricCearm 0.3586 (0.2681), with no statistical difference. One-way ANOVA showed that the roughness value of 0.4179 (0.04726) for Point 4 was significantly higher than for both tested composites and enamel.

Conclusions: After eight months of in-vivo functioning as class I restorations light reflection measuring of the surface roughness revealed better polishability and surface quality of ELS® and TetricCeram compared to Point 4.