Applying the Texture Analyser to the Dental Industry in Friction, Tension, Penetration and Adhesion

According to Statista, the global dental market is projected to grow to around 37 billion dollars by 2021, and current indicators show that the market will keep moving forward, primarily driven by the implant sector. Its success is due to progress in the fields of medical technologies and implant materials. Texture Analysis has an important role in the dental industry; this article contains some examples of dental research in recent years.

A Texture Analyser is a very useful tool for the research and development associated with dental products and has the capability to perform both imitative and fundamental measurements. Dental product testing solutions from Stable Micro Systems include dental fixative adhesiveness, chewing gum hardness, stickiness and coating crispiness, toothpaste consistency and extrudability, and dental floss tensile strength, as well as many more.

Examples of how Dental Products can be Tested – Friction and Wear

Horizontal Friction System attached to a Texture Analyser

When ceramic structures are used in the mouth, there is often a risk of wear between teeth and the ceramic part. Scientists from Tufts University School of Dental Medicine in Boston have been researching this effect when different dental ceramic systems are used. Disc shaped specimens were held in resin and they used their TA.XTplus Texture Analyser along with a multiple sample vertical friction wear device to perform wear simulation. No differences were found in the linear and volumetric reduction of enamel cusps abraded against enamel disks or ceramic specimens. Read more

In orthodontics, it is often necessary to reduce tooth structure interproximally to correct for inadequate space caused by dental crowding and in restorative dentistry to trim or contour various types of restorative materials such as amalgam, composite resin or porcelain (dental veneers). Abrasive strips are widely used in modern dentistry. They are usually thin, flexible, one-sided abrasive strips and are available in various sizes and grits. They are moved back and forth between the teeth to shape their sides.

Assessment of abrasion of dental strips on a Texture Analyser

The Abrasion Test Rig (HDP/ATR) was designed at Stable Micro Systems to originally provide a method of assessing the abrasion and/or frictional properties of abrasive strips by measuring the force resulting from the sliding of these strips against a ceramic cylinder during a tensile test on a TA.XTplus Texture Analyser. Exponent software is then employed to analyse the multi-peak force profiles obtained and apply special calculations to highlight differences between different grades and manufacturers of abrasive strips.

Examples of how Dental Products can be Tested – Tension

Flossing is a simple oral hygiene procedure that, when performed daily, can ensure healthy gums and teeth that last a lifetime. Experts say it is as indispensable to a healthy mouth as brushing, yet most people find it uncomfortable and do not do it regularly. Modern dentistry and dental products have begun to address the problem of plaque build-up which causes periodontal disease. For a manufacturer of dental floss wishing to compare the breaking strength of different formulations and compare with competitive samples, a tensile test is a quick and easy method.

For a sample such as dental floss, which is difficult to grip in standard tensile grips due to its smooth surface, Self-Tightening Roller Grips (A/TGT) are ideal. They are spring loaded and cross-hatched to provide the self-tightening mechanism, ensuring the sample stays firmly in place during the test.

Scientists from Witten/Herdecke University (Germany) have been investigating the influence of luting materials on the retention of cemented implant-supported crowns. Oral implant science has numerous topics of interest and evolving thematic trends in clinical studies. Since the 2000s, the focus of dental implantological treatment has been as a biological-driven therapy that recovers and maintains the function, long-term stability and aesthetics of soft and hard peri-implant tissues.

One of the actual topics of interest in the field of biological-driven implant therapy is implant restoration, and this topic induced the development of new methods and luting materials for implant-supported prosthesis retention. After being prepared then artificially stressed, the crowns were vertically removed using a TA.HDplus Texture Analyser. The obtained data showed that sandblasting and recementation of implant-supported cobalt chromium crowns resulted in a reduction of the retention force independent of the luting material. Find out more

Researchers from Jamia Hamdard (India) have been investigating the design and in vitro / in vivo evaluations of a multiple-drug-containing gingiva disc for periodontotherapy. Periodontitis is the commonest and most challenging progressive dental ailment and exhibits a wide spectrum of symptoms such as gingival puffiness, inflammation, bleeding, and detachment of tooth bone often leading to pocket formation of 3-4mm.

Tensile test using Self Tightening Roller Grips

This study set out to develop and evaluate a gingiva disc for the simultaneous delivery of multiple drugs to abolish infection, impede inflammation, avert collagen destruction, and promote alveolar bone regeneration. They used their TA.XT2 Texture Analyser to determine in vitro bioadhesive force and tensile strength. This customised, non-invasive polymeric gingiva disc was found to be a useful tool to treat acute to moderate stages of periodontitis. Read more

Examples of how Dental Products can be Tested – Penetration

Typical penetration test on a Texture Analyser

Over in Hangzhou, researchers from Zhejiang Gongshang University have been investigating the locking up of food between posterior teeth and its influence on chewing efficiency. Food particles are intra-orally locked up between antagonistic posterior teeth during each chewing cycle, and this can affect the selection of particles for subsequent breakage, hence also affecting chewing efficiency. The two aims of this study were to determine the extent of locking up and to examine the relationship between locking up and chewing efficiency. The researchers used their TA.XTplus Texture Analyser to perform penetration tests on sheet bolus samples. Relationships between locking up and chewing efficiency were successfully found. Read more

Examples of how Dental Products can be Tested – Adhesion

Around half of all denture wearers use an adhesive to help with both comfort and confidence. In this market, it is important to uphold standards of both texture and adhesive properties. Otherwise, customers will be uncomfortable at best, or if they rely on adhesive for denture retention, face the embarrassment of dentures becoming unattached during the day should the adhesive fail. Stable Micro Systems offer a wide range of testing techniques to assess the performance of denture glues. The best way of testing any adhesive product is to replicate its conditions of use as closely as possible. In all cases, if the adhesive is too strong the consumer will find removal very uncomfortable. Conversely, a weak adhesive is redundant and will not see repeat use.

Powder based adhesives are used by shaking a thin layer of powder onto the interior of the denture and pressing it onto the gum by biting down for a few seconds. Powder adhesive is well-suited to a standard adhesive test using a flat probe onto a flat surface, pulling the probe away from the surface. In this case, the environment must be moist and a range of pressures must be tested to represent the range of biting pressures of the target consumer group, while keeping the hold time constant.If suitable materials are available, a substrate made of a softer gum-like material may be used. The maximum force while withdrawing the probe corresponds to the force necessary to pull the denture directly away from the palate. This is particularly important for consumers who eat sticky foods and find the denture is pulled away during mealtimes. 

Paste adhesives only work well if applied in a thin layer. Consequently, the expulsion of the product from the tube is of high importance. The product must extrude in a controlled way with a force high enough to prevent the paste running out freely, but low enough that an elderly customer can use the product without any help.Finally, adhesive lining strips also face the difficulty of providing an optimum holding force. These are moistened and laid down on the denture surface, again fixed in place by applying pressure in the mouth. 

The Multiple Indexing Plate by Stable Micro Systems offers an excellent testing solution for strip adhesives. This plate allows ten individual adhesive tape tests to be performed on a single sample (or ten smaller samples) using a domical probe. As with the powder test, the moisture level must be kept constant during this test as the adhesive relies on a small amount of water to adhere to the roof of the mouth.

Scientists from the University of Otago (NZ) used their TA.HDplus Texture Analyser to perform tensile testing for bond strength determination of porcelain to enamel and dentin. Traditional methods of high-speed rotary cavity preparation have been found to cause additional damage. This study aimed to investigate the effect on bonding of preparations using ultrasonic instruments, rather than rotary, looking at both the bonding strength of enamel and dentin as well as the effect of etching. Ultrasonic preparation was found to produce a greater bond strength than rotary preparation. Read more

Typical adhesive test on a Texture Analyser

The worldwide effort to push forward standards for the provision of quality oral health care drive a large research effort in both academic and industrial settings. A large component of this research is based around Texture Analysis, ensuring the products used by dentists and consumers every day are the best they can be.

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For more information on how to measure texture, please visit the Texture Analysis Properties section on our website.

The TA.XTplus texture analyser is part of a family of texture analysis instruments and equipment from Stable Micro Systems. An extensive portfolio of specialist attachments is available to measure and analyse the textural properties of a huge range of food products. Our technical experts can also custom design instrument fixtures according to individual specifications.

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