Posterior overlays are commonly used in today’s dentistry. They are more conservative than crowns and offer better morphology and material options than direct restorations. There is no standard consensus for the optimal overlay design. This study aims to explore the available literature on posterior overlay preparation designs concerning thickness, preparation margins, and retention forms. A comprehensive review of the literature was conducted in the different databases from 1990 to 2024. The inclusion criteria were the peer-reviewed articles and clinical trials comparing the margin, thickness, or retention of the posterior overlay preparations. Published works that included metal overlays alone or were not published in peer-reviewed journals, and case reports, were excluded. In this review, 26 studies met the inclusion criteria. The thicknesses used in the studies ranged from 0.5 to 2mm, with common values including 1mm, 1.5mm, and 2mm across various materials. The preparation margin types, ranked from most to least frequent, included butt joint, shoulder, chamfer, and beveled. Non-retentive and retentive designs were used in a similar number of studies. Conservative anatomic preparations that are 1.5 to 2 mm in thickness are preferred for posterior overlays. This approach has the advantage of preserving tooth structure and giving less invasive as well as more long-lasting restorations. Butt joint margins were most frequently used for non-esthetic, posterior restorations. Consideration should also be given to alternative margin designs, such as chamfer, based on specific conditions and requirements, particularly when incorporating digital methods.
Type of Study:
Review article |
Subject:
So on Received: 2024/08/25 | Accepted: 2024/11/20 | Published: 2024/11/20