Co-existing, Compatible Biomaterials – Phillip Silver Solvay

Featured Products Promotional Features

  Posted by: Dental Design      3rd March 2019















Over the last 60 years or so, there has been considerable growth in the use of biomaterials. Whether synthetic or natural, living or lifeless, these materials are developed to interface or perform with the biological systems of the body and are used to treat, replace and even regenerate natural tissues and organs to restore normal function.[1]The health and lives of millions of people are improved or prolonged with implants, prostheses and devices used to substitute or supplement human tissue in many parts of the body. Applications vary substantially but devices such as artificial limbs, organs and joints, pacemakers, drug delivery systems as well as dental implants and dentures form a significant part of modern health care.[2]

There are a wide variety of different biocompatible materials, yet what distinguishes them from other materials is their ability to co-exist and perform a specific function in contact with human tissues and without causing harm to the body.[3]With our focus on dentistry, materials that are used in the oral cavity, whether to treat, reconstruct, replace or augment the dentition or its function should be harmless to all oral tissues including the gingiva, mucosa, pulp and bone. They should not be composed of anytoxic, leachableor diffusible substancesthat could beabsorbed into the body or contain any agents that could produce a local or systemic allergic reaction.[4]

As dental professionals are aware, the oral cavity is teeming with bacteria, plaque and saliva and the effects of these, along with the pH levels within the mouth and functional forces can make it an unfriendly environment for many materials. Equally, the materials used for dentistry are not natural tissues and are not likely to be accepted by the body in the same way. Furthermore, although dental materials are manufactured to be inert and biologically inactive, there is still the potential for some materials to shrink or distort, alter in stability, dissolve or even corrode,[5]thereby increasing the risk of immune reactivity or harm to the oral tissues.

The use of metals in dentistry is an area of particular concern, and the potential for metallic allergens has been described assizable.[6]Metal hypersensitivity is a common condition affecting 10 to 15 per cent of the general population. It has been estimated that up to 17 per cent of women and 3 per cent of men are allergic to nickel and up to 3 per cent are allergic to cobalt and chromium.[7]The prevalence of contact allergy to gold and palladium is also high[8]and even titanium, a proven biocompatible metal can cause inflammatory reactions to a small number of patients.[9]Metal-sensitive patients can experience a variety ofsymptoms, which may rangefrom oral mucosal changes and skin disease to excessive fatigue andautoimmune diseases.[10]

Metal is commonly used for orthodontic appliances, dental implants and restorations and due to its strength and durability, cobalt-chromium is frequently considered to be the most favourablematerial for removable partial denture (RPD) frameworks. The advantages of metal-based frameworks are that they are light but rigid and offer strength and stability. They can be designed to minimise the covering of gingival margins and as they conduct heat and cold effectively, they provide a relatively natural experience. However, along with concerns regarding metal hypersensitivity, metal RPDs also may present problems with oral galvanism, altered taste, adverse tissue reactions and osteolysis of abutment teeth. In addition, metal clasps can become distorted with age and stress, which may adversely affect the fit and function of the RPD. Also the visibility of metal clasps in the aesthetic zone can be a significant issue for many patients.[11]

Obviously, acrylic or flexible nylon materials can be used to fabricate RPD frames. However, acrylic is mechanically weak and prone to fracture and frames made from this material often feel bulky and unnatural as they require greater mucosal coverage to gain retention.[12]Flexible dentures are more resistant to fracture and are thinner and lighter than conventional acrylic. Furthermore, as they are fabricated from nylon, flexible RPDs can adapt to the shape and movement of the mouth,[13]they also offer good aesthetics and tend to be more comfortable to wear.

Nevertheless, with the intention of bridging the gap between flexible and metal RPDs, Solvay Dental 360®has custom-developed a biocompatible, high performance polymer specifically for the fabrication of RPD frames. Ultaire®AKP is a new generation material that offers patients a lightweight, metal-free, taste-free alternative to conventional materials. This material was designed to improve the patient experience and has bone-like properties with the elasticity and flexural strength to withstand loading, increase comfort and produce a natural feel. RPD frames fabricated from Ultaire®AKP provide superior aesthetics with strong, stable retention and fit that is not harmful to natural tissue, offering a viable option to patients that are susceptible to allergies or would prefer not have metal in the mouth.

The innovation behind the manufacture of dental devices used to replace natural tissues is without doubt advanced. However, to successfully meet the needs of each individual patient, dental professionals still need to examine the biocompatibility of dental materials in order to offer their patients a choice of suitable options.


To book a Solvay Dental 360®Professional Lunch and Learn or to find more information Ultaire®AKP and Dentivera®milling discs,
please visit




[1]Williams D.F. The Williams Dictionary of Biomaterials. Liverpool University Press. 1999. [Accessed 14thNovember 2018]

[2]Khan W. et al. Implantable Medical Devices. Chapter 2 in: Domb A., Khan W. (eds) Focal Controlled Drug Delivery. Advances in Delivery Science and Technology. Springer, Boston, MA.[Accessed 14thNovember 2018]

[3]Williams D.F. On the mechanisms of biocompatibility. Biomaterials 2008 1-13.[Accessed 14th November 2018]

[4]Yildiz O. et al. Biocompatibility of dental polmers in book: Polymer science, practical applications and educational aspects, Mendez Vilas A. et al. 89-98.[Accessed 14th November 2018]

[5]Bayramoğlu G. et al. The effect of pH on the corrosion of dental metal alloys. J Oral Rehabil. 2000 Jul; 27(7) 563-575.[Accessed 14th November 2018]

[6]Teo ZWW et al, Hypersensitivity reactions to implanted metal devices: Facts and Fictions. J Investig Allergol Clin Immunol 2016; Vol. 26(5): 279-294.[Accessed 26thJune 2017]

[7]Thyssen JP et al. Metal allergy–a review on exposures, penetration, genetics, prevalence, and clinical implications. Chem Res Toxicol. 2010 Feb 15;23(2):309-18.[Accessed 26th June 2017]

[8]Raap U et al. Investigation of contact allergy to dental metals in 206 patients. 2009. Contact Dermatitis, 60: 339–343. doi:10.1111/j.1600-0536.2009.01524.x

[Accessed 26thJune 2017]

[9]Sicilia A. et al. Titanium allergy in dental implant patients: a clinical study on 1500 consecutive patients. Clin Oral Implants Res. 2008 Aug;19(8):823-35.[Accessed 19th November 2018]

[10]Stejskal V. et al. Diagnosis and treatment of metal-induced side effects. Neuro Endocrinol Lett. 2006 Dec;27 Suppl 1:7-16.[Accessed 26th June 2017]

[11]Campbell S.D. et al. Removable partial dentures: The clinical need for innovation. Journal of Prosthetic Dentistry 2017; 118(3) 273-280.[Accessed 19th November 2018]

[12]Goodall W.A. et al. Unilateral removable partial dentures. Table 1: Advantages and disadvantages of various types of unilateral RPD. BDJ Jan 2017. 222, 79-84.[Accessed 19thNovember 2018]

[13]Sharma A. et al. A Review: Flexible Removable Partial Dentures. IOSR Journal of Dental and Medical Sciences. Dec 2014;13(12) Ver.VI. 58-62.[Accessed 20th November 2018]

No Comments

No comments yet.

Sorry, the comment form is closed at this time.