Restorative dentistry: the journey to CAD/CAM – Mark Allen

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  Posted by: Dental Design      11th May 2018

History books are rich in information about the field of restorative dentistry in the days of the Babylonians, Assyrians, Egyptians, Etruscans and Phoenicians. They tell us of the earliest uses of cast restorations, where copper and gold were widely used, to how entire bridges were made of soldered gold bands as early as 500 BC. By the 1880s the materials in use for indirect restorations had evolved significantly thanks to various advancements, including the introduction of porcelain inlays in 1857 and the first dental cement, oxychloride of zinc, in 1860.

Soon after, changes in restorative dentistry came thick and fast with the establishment of a revolutionary technique for making gold castings by William Taggart in 1907, Van Hoy’s methods of compensation for alloy shrinkage and more recently, the use of ceramic. As a result of ongoing research and technological innovation, there are now a number of restorative materials in use across the world that have built upon the properties of first generation products to provide an aesthetic yet functional restoration for the patient.

One of the latest advancements is a computer-assisted fabrication system (CAD/CAM), which is designed to offer long-lasting, high levels of strength and increased accuracy for the fabrication of indirect restorations. Unlike the traditional pathway that requires impression taking, CAD/CAM fabrication takes a much more streamlined approach and can help to improve accuracy, speed and improve aesthetics.

Naturally, the drive behind CAD/CAM manufacturing has led to improvements in the actual restorative materials themselves, with significant changes being made to polymerisation modes, microstructures and matrix compositions in recent years. Common materials used in the production of CAD/CAM restorations are glass-ceramics, ceramics and resin composites. It can be difficult to know which way to turn, but research indicates that there are a number of benefits to the patient and practitioner in using composite CAD/CAM blocs over other materials and techniques available.

Generally, the polymerisation modes used for CAD/CAM composite blocs – with high temperature and/or with high pressure – are thought to greatly increase the degree of conversion compared to light-cured composites.[i]Alongside this, advances made in current composite blocs have allowed for the augmentation of the filler content as well as the realisation of more homogenous structures with fewer flaws – not to mention that toxicity and monomer release have been shown to be low.[ii]

With higher flexural strength and favourable elasticity modulus that is similar to dentine, thanks to the microstructure of many CAD/CAM composite blocs, masticatory forces are often softened too. This, in turn, helps to increase masticatory comfort for patients and reduces the likelihood of fractures, to provide longer-lasting results, enduring comfort and ultimate functionality. The better the CAD/CAM composite bloc, however, the better the filler ratio and lower the modulus of elasticity, which will have an impact on the abrasion qualities. That’s why for patients suffering from bruxism or looking to have an implant-supported crown, CAD/CAM composite restoration solutions can offer a more successful outcome. Because of these qualities, high-performance composite blocs have been shown to rival CAD/CAM materials made solely from glass-ceramic as bonded partial restorations and crowns on natural teeth and implants.i

What’s also good about CAD/CAM composites is that they exhibit excellent machinability qualities and can be milled in very low thicknesses.[iii]Moving forward, this might pave the way for the development of minimally invasive treatment strategies, such as ‘no prep’ treatment of worn dentition.

Out of the materials currently available on the market, COLTENE’s BRILLIANT Crios reinforced composite bloc has shown significant benefits to both patient and practitioner. Its broad application makes it ideal for everyday procedures in the dental practice, though it also provides a quality restorative treatment solution for patients with bruxism or implant-supported crowns. This is because of the material’s unrivalled shock-absorbing abilities, high flexural strength and high resistance. On top of all that, BRILLIANT Crios has a great lustre and blends in extremely well with the surrounding teeth to provide patients with a natural, aesthetically pleasing smile.

Using reliable, high-performance materials for indirect restorations will be key moving forward, with demand for long lasting, aesthetic, functional restorations from patients greater than ever before. CAD/CAM materials such as the BRILLIANT Crios will no doubt play an important role in this, especially in certain indications, as will ongoing research and technological advancements. We’ve come a long way since the techniques and materials of the Babylonians, Assyrians, Egyptians, Etruscans and Phoenicians, and innovation must remain a priority for professionals providing inlays, onlays, crowns and veneers to patients.

 

To find out more visit www.coltene.com, email info.uk@coltene.com

or call 01444 235486

 

 

 

 

[i]Mainjot AK, Dupont NM, Oudkerk JC, Dewael TY, Sadoun MJ. From Artisanal to CAD-CAM Blocks: State of the Art of Indirect Composites. J Dent Res. May 2016; 95 (5): 487-95. Accessed online 15 November 2017 at https://www.ncbi.nlm.nih.gov/pubmed/26933136

[ii]Mainjot AK. Recent advances in composite CAD/CAM blocks. The International Journal of Esthetic Dentistry. 2016; 11(2). Accessed online 15 November 2017 at http://eaed.org/wp-content/uploads/2016/08/ejed_2016_02_s0275.pdf

[iii]Ruse ND, Sadoun MJ. Resin-composite blocks for dental CAD/CAM applications. J Dent Res. December 2014; 93 (12): 1232-4. Accessed online 15 November 2017 at https://www.ncbi.nlm.nih.gov/pubmed/25344335


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