INBDE (Integrated National Board Dental Examination) 2026 – 400 Free Practice Questions to Pass the Exam

The 'skirt' feature is essential in a gold onlay preparation to contribute both to retention and resistance forms. A skirt is a bevelled margin that adds resistance and retention to the restoration. It increases the total occlusal convergence angle of the preparation, providing more stability and support for the restoration. Without the skirt feature, the preparation may lack retention and resistance, making it more prone to dislodgement or fracture. Option A is incorrect because the skirt feature is not for aesthetic purposes. Option B is incorrect as the skirt feature does not solely contribute to retention, but also to resistance form. Option D is incorrect as the skirt feature does have an impact on both retention and resistance forms.