Evaluation of 2-year Clinical Performance of Two Different Single Color Universal Composite Resin Restorative Materials: A Double-blind Prospective Randomized Controlled Trial.

Dentists have recently preferred to use composite materials and restorative techniques that allow the use of simplified clinical protocols in order to reduce the time the patient spends in the dentist's chair and minimize technical sensitivity. Color selection in the clinic is a very sensitive process and is affected by environmental factors and operator-related variables. This has led to the development of single-color universal composite resins that aim to facilitate color selection. These materials have a universal opacity and several Vita shades and are recommended by manufacturers to be used in a single color layer that can match different tooth colors. In recent years, monochromatic universal composites have been developed that are supposed to be compatible with all Vita Classic Scale shades from A1 to D4. Manufacturers report that single-color universal composites can be applied to teeth of all colors without using the layering technique using different color composites.

OMNICHROMA (Tokuyama Dental) is the first universal composite resin restorative material that is claimed to aesthetically match every tooth color from A1 to D4 in a single shade. The manufacturer declares that OMNICHROMA, with its equally sized supra-nano spherical filler (260 nm spherical silicon dioxide-Zzirconium dioxide), adapts to each of the 16 VITA classic colors thanks to Smart Chromatic Technology.

Zenchroma (President Dental) is a hybrid composite material containing an ultra-thin, radiopaque glass filler. The manufacturer declares that the filling color perfectly adapts to the tooth structure with its chameleon effect.

As we know, there is no study investigating the clinical performance of these two universal composites. The aim of this study is to compare the clinical performance of 2 different single-color universal composite resin materials (OMNICHROMA and Zenchroma) in the restoration of non-carious cervical lesions with the control group (Filtek Z250, 3M), which is a multi-color composite resin material, using modified USPHS and FDI criteria.

In this study, two different null hypotheses were established. The first null hypothesis of this study is; It is concluded that there is no difference between 2 different single color universal composite resin materials (OMNICHROMA and Zenchroma) in terms of clinical performance in restorations of non-carious cervical lesions. The second null hypothesis of the study is that universal composite resin materials are not different from the control group, multicolored composite resin (Filtek Z250, 3M), in terms of clinical performance in restorations of non-carious cervical lesions.