Marginal Discrepancy Is Not Solely a Laboratory Issue.

From tooth preparation and digital impressions to CAD design and manufacturing, every stage of the workflow influences marginal fit. In this article, we explain the most common causes of marginal discrepancy and how they can be minimized through a predictable digital workflow.

What Causes Marginal Discrepancy? Factors Affecting Marginal Fit in Dental Restorations

What Is Marginal Discrepancy?

Marginal fit is one of the most critical indicators of a successful dental restoration. The adaptation between the restoration margin and the prepared tooth directly affects esthetics, function, and long-term biological success.

However, marginal discrepancy is not caused by the laboratory alone. Every stage of the workflow—from the dental clinic to the laboratory—has a direct impact on the final marginal fit.

At Maestro Dental Lab, we view marginal fit as the outcome of a comprehensive digital and technical workflow rather than the result of a single production stage.

What Causes Marginal Discrepancy?

1.⁠ ⁠Inadequately Defined Preparation Margins

Accurate preparation is the foundation of optimal marginal fit.

When preparation margins are not clearly visible, the restoration margin cannot be designed with the required level of precision. This is particularly challenging in subgingival preparations, where soft tissue may obscure the finish line.

For this reason, it is essential that preparation margins are clearly captured in the digital impression or model provided to the laboratory.

2.⁠ ⁠Incomplete Digital Impression Data

Although digital impression systems provide exceptional accuracy, incomplete scans or insufficient capture of preparation margins can negatively affect marginal fit.

Before initiating production, we carefully evaluate every digital impression. If additional scan data is required, we request a rescanning from the clinician to ensure an accurate and predictable workflow.

3.⁠ ⁠The CAD Design Process

Marginal fit is determined not only during manufacturing but also during the design stage.

During the CAD design process, the following parameters are evaluated together:

•⁠  ⁠Preparation margins

•⁠  ⁠Cement space

•⁠  ⁠Internal adaptation

•⁠  ⁠Restoration thickness

A well-designed restoration provides the foundation for a predictable manufacturing process.

4.⁠ ⁠Manufacturing Precision

Every manufacturing stage—including milling, sintering, and characterization—must be performed within controlled tolerances.

Regularly calibrated production equipment and standardized manufacturing protocols play a critical role in maintaining accurate marginal adaptation.

5.⁠ ⁠Internal Adaptation and Seating Verification

In some cases, the restoration margin may appear accurate while minor internal contact points prevent complete seating.

For this reason, our quality control process evaluates not only the external margins but also the internal adaptation of every restoration.

6.⁠ ⁠Occlusal Contacts

Premature occlusal contacts or excessive occlusal height may prevent the restoration from seating completely.

Therefore, occlusal evaluation is also included as part of our final quality control procedure.

7.⁠ ⁠Cementation

Marginal fit is not determined solely in the laboratory.

During cementation, factors such as:

•⁠  ⁠Excess cement

•⁠  ⁠Incomplete seating of the restoration

•⁠  ⁠Cementation technique

may also influence the final marginal adaptation.

Achieving predictable results therefore requires close collaboration between the clinician and the dental laboratory.

How We Minimize Marginal Discrepancy

At Maestro Dental Lab, every restoration undergoes multiple quality control stages before and after production.

Our standard quality protocol includes:

•⁠  ⁠Digital impression verification

•⁠  ⁠Preparation margin assessment

•⁠  ⁠CAD design review

•⁠  ⁠Internal adaptation evaluation

•⁠  ⁠Marginal fit inspection

•⁠  ⁠Occlusal assessment

•⁠  ⁠Final esthetic evaluation

Our goal is not simply to manufacture restorations, but to deliver restorations that provide predictable fit and long-term clinical success.

At Maestro Dental Lab, we approach every case with this comprehensive philosophy. By combining advanced digital technologies, experienced dental technicians, and a multi-stage quality control system, we provide clinicians with reliable, precise, and predictable restorative solutions.