One challenge faced by dental professionals is that, unlike natural tooth structure, composite restorations do not lighten when exposed to bleaching agents. As a result, functional restorations may need replacement after bleaching to match the newly whitened teeth. However, replacing a composite restoration can lead to unnecessary removal of tooth structure, potentially weakening the tooth and increasing its susceptibility to further iatrogenic damage. This study will investigate the ability of Omnichroma restorations to shade-match tooth structure after bleaching.

The null hypotheses will be:

1. Single-shade RBC will not exhibit similar shade and optical behavior to conventional RBC across all anterior restorations following bleaching.
2. Patient satisfaction regarding color blending between the restoration and tooth structure will not differ according to the type of material used.
3. Dentist satisfaction regarding color blending between the restoration and tooth structure will not differ according to the type of material used.

Selecting the proper shade for a restoration is of vital importance for achieving optimal aesthetic results. However, shade selection can be time-consuming, somewhat subjective, and heavily reliant on the clinician's visual judgement.

This study will explore the ability of Omnichroma restorations to shade match tooth structure after bleaching. Patients visiting the JUST dental clinics who have at least two anterior restorations (one Omnichroma restoration and one multi-shade nanohybrid composite restoration) will be recruited for this study. The calculated sample size for the study is 240 teeth.

The shade and the L*a*b* scores will be recorded using spectrophotometer prior to bleaching and after bleaching. Two blinded, calibrated dentists will independently evaluate the resulting shade outcomes and assess the degree of color match between the restorations and the adjacent teeth after bleaching. This assessment will be categorized as either match or no match. The patient's satisfaction will also be recorded two weeks after bleaching.

Inclusion Criteria:

1. Patients who are willing to come back for follow-up appointments.
2. Patients who are willing to sign an informed consent form.
3. Patients with well documented clinical records and have at least two anterior restorations (both Omnichroma and conventional multi-shade nanohybrid composite.)
4. Patients aged 18 years or older.
5. Patients with good oral hygiene
6. Patients with vital teeth.
7. Patients who are willing to have the restorations replaced later if necessary if there is a color mismatch after bleaching treatment.

Exclusion Criteria:

1. Individuals with severe bruxism or periodontal disease.
2. Patients with non-vital teeth restored with composite fillings.
3. Patients with severe tooth discoloration.
4. Patients with fluorosis or tetracycline staining.
5. Heavy smokers.
6. Pregnant or nursing women.
7. Patients undergoing orthodontic treatment.
8. Patients with enamel or dentin deformations.

Double (Participant, Outcomes Assessor) The patients who participated in the study and the assessor of the treatment outcome do not know the type of treatment procedure received.