CAD/CAM vs. Traditional: Which Dental Framework Wins?
"A close look at marginal and internal fit in implant-supported frameworks."
For years, computer-aided design and manufacturing (CAD/CAM) systems have revolutionized dentistry, offering a seemingly faster and more precise way to create dental restorations. These systems, whether subtractive or additive, have been increasingly used for fabricating cobalt-chromium (Co-Cr) frameworks, especially for long-span restorations. However, a crucial question remains: how does the accuracy of these CAD/CAM frameworks compare to traditional methods?
Achieving a precise fit is paramount for the success and longevity of implant-supported restorations. Ill-fitting frameworks can lead to complications like screw loosening, cement washout, and even biological issues such as inflammation and bone loss. Therefore, understanding the marginal and internal fit of different manufacturing techniques is essential for clinicians.
This article delves into a recent study that compared the marginal and internal fit of implant-supported, cement-retained 5-unit Co-Cr metal frameworks. The frameworks were fabricated using three different techniques: lost wax (LW), CAD-CAM milling, and selective laser melting (SLM). By examining the findings of this research, we aim to provide clarity on which manufacturing technique offers the most accurate fit and ultimately, the best outcome for patients.
Market Growth and Forecasts
The listed market reports give different estimates of the dental CAD/CAM market’s size and growth. Growth Market Reports puts the global Dental CAD/CAM Systems market at USD 3.2 billion in 2024, while Research and Markets estimates $2.39 billion in 2025 and projects $2.67 billion in 2026, a 11.6% CAGR. For 2026–2034, Fortune Business Insights projects growth from $2.63 billion to $5.65 billion at a 10.01% CAGR, whereas Straits Research projects growth from $2.89 billion to $5.45 billion at an 8.24% CAGR. These figures are not directly interchangeable because the reports give differing estimates and forecast periods.
Marginal and Internal Fit: The Key to Long-Term Success
The study meticulously evaluated the marginal and internal fit of the frameworks. Researchers fabricated a total of 30 Co-Cr metal frameworks, designed for 5-unit implant-supported restorations. These frameworks were created using three different manufacturing techniques, ensuring a robust comparison between the methods. The chosen techniques represent a spectrum of approaches:
- Lost Wax (LW): A traditional technique involving creating a wax pattern, investing it in a mold, and then casting the metal framework.
- CAD-CAM Milling: A subtractive technique where the framework is milled from a solid block of material using computer-controlled machinery.
- Selective Laser Melting (SLM): An additive technique where the framework is built layer by layer by melting metal powder with a laser.
Reviews Examine Digital Restorative Dentistry
The listed literature covers CAD/CAM across restorative dentistry, general dentistry, and removable partial denture (RPD) framework fabrication. A review of RPD frameworks focuses on the accuracy of CAD/CAM systems compared with conventional manufacturing methods. Another review examines current evidence on clinical outcomes and performance of CAD/CAM and 3D-printed inlays, onlays, and veneers. A general dentistry review describes digital processes as contributing to more efficient, precise, and predictable treatment, while also examining their uses, benefits, and challenges.
Framework Fit Under Comparison
An in vitro study compared the marginal and internal fit of implant-supported, cement-retained five-unit Co-Cr metal frameworks made using three techniques: lost wax (LW), CAD/CAM milling, and selective laser melting (SLM). The source establishes that fit was the focus of the comparison, but its supplied summary does not report the results or identify a winning method. It therefore supports treating fit as a question for direct comparison, not a basis for claiming that one technique performed better.
The Verdict: Which Technique Offers the Best Fit?
The results of the study revealed significant differences in marginal fit between the manufacturing techniques. CAD-CAM milling techniques exhibited the widest mean marginal discrepancy values (84 µm), indicating a less accurate marginal fit compared to the other methods. In contrast, the lost wax technique demonstrated the lowest mean marginal discrepancy values (36 µm), suggesting a superior marginal fit.
Efficiency and Fit Remain Central Questions
The supplied 2016 critical review characterizes CAD/CAM as changing dental restoration processes and making them easier and more efficient for dentists, patients, and dental technicians. The article titled “CAD/CAM vs. Traditional: Which Dental Framework Wins?” frames accuracy, fit, and long-term success for implant-supported restorations as key comparison questions. The supplied material does not provide results establishing which method has better fit or long-term success, so it does not resolve the comparison.
Adoption and Attitudes Toward Digital Dentistry
One study set out to examine awareness, understanding, and attitudes toward digital technology in dentistry, with particular attention to CAD/CAM. Its supplied summary describes the shift from conventional methods to digital technology as widely discussed but does not state the study’s findings. A separate 2024 ResearchGate item describes CAD/CAM advances as driving a transformation in dental restoration, but the supplied summary gives no specific adoption data or system-wide barriers.
A Case Study of Personalized Restorations
A case study published June 28, 2024, describes the use of CAD/CAM systems and intraoral scanners to create personalized dental restorations. Its accompanying PDF highlights the Medit i700 intraoral scanner for detailed dental impression scanning. The study reports that adopting these technologies can save time, enhance patient satisfaction, and reduce costs in the long run. These points are presented as the case study’s account of potential benefits.
Interestingly, axial discrepancy values were similar for all manufacturing techniques, indicating that the techniques performed comparably in this aspect. However, the highest internal gap values were measured at the occlusal area, with the following values: LW (154 µm), CAD CAM milling (212 µm), and SLM (290 μm). These findings suggest that the internal fit at the occlusal area may be a critical factor to consider when selecting a manufacturing technique.
In conclusion, the study suggests that while CAD/CAM technology offers advantages in terms of speed and automation, it may not always provide the most accurate fit, particularly in the marginal area. The lost wax technique, despite being a more traditional method, demonstrated superior marginal fit in this study. Clinicians should carefully consider these findings when selecting a manufacturing technique for implant-supported frameworks, weighing the benefits of CAD/CAM technology against the potential for compromised fit. Further research and advancements in CAD/CAM technology are needed to improve the accuracy and predictability of these techniques.