NEWS Summer 2018Issue 79

The OTA Conference Needs

YOU!

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Contents

Inside this issueNews and Features

Chairs Report 3

Tongue Piercings May Bring Harm to Teeth and Gums 4

OTA Report on the DTS 2018 8

3Shape Patent Infringed 10

2018 The First Annual Conference 11

Baby Teeth Give Clues to Autism’s Origins Detection 19

Building Business 22

Memories of an old codger 26

Thermoplastic Materials in Dental Technology 29

Meetings and Conferences

2018 OTA Conference 11

Upcoming Events 25

Continuing Professional Development

Verifiable CPD Questions 32

CPD Submission Form 33

Article submission criteria for OTA members 37

Directory of OTA officials 38

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Chair’s Report By Andrea Johnson

Hello and welcome to this special conference edition of the OTA News. As I’m sure you’re aware, over the past two years we have tried a conference format that ran alongside the BOC instead of our traditional OTA conference, this unfortunately didn’t work out, so although it was a very good experiment to try and work more closely with our clinical colleagues, it was not to be. However do not be sad! All is not lost...

We are now returning to a more independent, intimate and financially sustainable conference setting; this will be in a similar format to our traditional conferences but with a twist. This time we are opening up our conference to the whole

dental team, to our fellow technicians from other disciplines, to nurses, therapists, hygienists to clinicians and anyone else with an interest in the dental field. To achieve this we have been working closely with other groups and intend to bring even more on board next year. This year we have combined efforts and resources with the Dental Technologists Association (DTA), The Society of British Dental Nurses (SBDN) and Blueprint dentals FutureLabs event.

I am very excited about this collaboration as any who have spoken to me about it will attest. We all have friends and interests than span all aspects of the dental field and to be able to have the opportunity to come together and learn and socialise together is one not to be passed up. This event promises to be a really great event with new aspects to our programme which will be suitable and interesting for all whilst keeping the same ever popular format and social events that we all love. Friday morning we will start with workshop sessions then Friday afternoon and Saturday will be lectures. There will be a choice for you on both days so you can tailor your own programme to suit your interests.

On the Thursday for those early birds you will have the opportunity to join the OTA council and invited speakers etc for a meal in the Ye Olde Trip to Jerusalem just around the corner from the hotel. There is a small extra charge for this but it will be very well worth it. On Friday we have a welcome drinks reception and buffet dinner in the conference hotel and on Saturday we will have the Black tie conference banquet and awards dinner.

As well as good food and great company we will have a live band and photo booth for you to enjoy on your last night together. All this mixed in with some fantastic speakers from both the UK and abroad. Speakers such as Waleed Ibrahim, Julianne Kumm, Janine Doughty, John Brown, Stuart Marlow, Lesley Sharpe, Ashton Sheerkhan, Desmond Soloman, Larry Browne, Tony Knight, Matthew Hill, GP Visser and more besides. Our speakers will be covering topics such as: Gingival Characterisation for natural looking dentures, Sleep Apnoea, Intraoral scanning for Difficult Patient Groups, a History of Ceramics, Cosmetic Camou-flage, Shifting the balance: a better, fairer system of dental regulation, Homelessness and oral health: inequalities and opportunities, Digital Orthodontics. Choices, Obstacles and Limitations and Orthog-nathic surgery and much more besides.

I truly hope you can join us as I would love to see you all there. For more information and application forms go to: https://ota-uk.org/ota-conference/ or contact me or any of the OTA council directly and we will be happy to assist you.

See you soon!Andrea.OTA Chair

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Tongue Piercings May Bring Harm to Teeth and Gums

By Dennis ThompsonHealthDay Reporter

You might think a tongue piercing is sexy and cool, but these hip accessories do your oral health no good at all, researchers say.

People with a tongue piercing appear more likely to suffer from gum disease more often than those with a lip piercing, a Swiss study has concluded.

Researchers found more cases of bleeding, receding or inflamed gums among a group of 14 patients with a tongue piercing, said senior researcher Dr. Clemens Walter, deputy superintendent of the University Center for Dentistry with the University of Basel in Switzerland.

“The closer teeth were to a tongue piercing, the more affected they were,” Walter said.

On the other hand, the gum health of seven patients with a lip piercing appeared unaffected by the jewelry, according to findings presented at the just-concluded European Federation of Periodontology’s meeting in Amsterdam.

A separate study from Belgium found that two young women (ages 27 and 32) with tongue piercings suffered repeated gum damage due to the pressure of metal against their teeth.

After eight to 10 years, the women had their piercings removed after gum bleeding and infection resulted in repeated abscesses, loose teeth and movement of teeth out of their normal position, researchers said.

“For both patients, time-consuming and costly surgical treatment and antibiotics were needed, and complete regeneration of the lost tissue could not be achieved,” Dr. Bernard Loir, a dentist in Brussels, said in a prepared statement. He presented the findings at the same meeting.

Tongue piercings interfere with eating, swallowing and speaking, and cause irritation and damage by constantly rubbing and clicking against the teeth and gums, Walter and Loir said.

“Patients with a tongue piercing always play with the piercing and push the piercing to the teeth, especially the lower front teeth, causing mechanical irritation,” Walter said.

American Dental Association spokesman Dr. Tyrone Rodriguez compares tongue piercings to “little wrecking balls” inside the mouth.

“The hard structure hits against the tooth, and that constant tapping causes micro-cracks that eventually become big cracks that cause the tooth structure to fail or the tooth to become

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very, very sensitive,” said Rodriguez, a pediatric dentist in Moses Lake, Wash.

Oral piercings also increase a person’s chance of infection, given that the human mouth plays host to more than 500 known types of bacteria, fungi and viruses, Rodriguez added.

“The mouth holds its own fairly well, but we push things in favor of being complicated when we punch a hole in those protective barriers,” Rodriguez said. “A lot of the bugs we have in the mouth are considered opportunistic. Whenever we have an injury or lesion, they try to take advantage.”

Walter is steadfast that if patients care about their oral health, they will remove their tongue piercing as soon as possible.

“They have to remove it. There’s no other choice,” Walter said. “According to my data and the cases I have seen, they have to remove, and usually they do it. If you explain it to the patient, he removes the piercing.”

People who refuse to remove their tongue piercing should practice immaculate oral health, Rodriguez said.

“The best option is always not to have the piercing, but if you must have the piercing, keeping it clean is vitally important. It’s also helpful to have a piercing you can remove so you can clean it properly,” Rodriguez said.

Piercers also should refrain from vaping or smoking either tobacco or marijuana, Rodriguez added.

“If you have a piercing and you’re bombarding it with all these irritants and potential carcinogens, well, that complicates things,” he said.

Research presented at meetings is generally considered preliminary until published in a peer-reviewed journal.

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OTA Report On The DTS 2018First of all we would like to thank all of our members for visiting our stand at the DTS show, we had two extremely busy days and it was great to chat to existing and new members, we also had a good number of technicians who approached our council members interested in more information on the OTA resulting in new memberships being processed.

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Our Lecture programme was a great success as we had some interesting topics being presented, each lecture was attended to a high capacity and positive feedback was given to our council members from some of the delegates who attended.

We would like to thank all of our guest lecturers for the time and effort they put into their presentation, everyone delivered with the upmost professionalism and the council was ex-tremely pleased with their efforts.

Here are a few of the speakers in action at the OTA lecture theatre:

Snoring & sleep apnoea – mandibular advancements appliances: a role for the laboratory.

Matt Everatt kicked off the OTA seminar programme with his summary and overview of Snoring and OSA, and the treatments available.

Evolution of Light Cure and LC twin block technique.Stephen Prime talked about the evolution of light cure materials in orthodontics and its use within the laboratory.

Mandibular Repositioning Devices (MRD’S) for the treatment of snoring and obstructive sleep apnoea within the NHS hospital service.

Lucia Amato provided us with a broad overview of some of the Mandibular Repositioning devices.

We look forward to doing it all again at DTS 2019

Jennifer AlexanderSpecialist Orthodontic / Prosthetic TechnicianCrosshouse University Hospital, Kilmarnock.

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Complaint alleges 3Shape’s patented Color Recording technology infringed by the ITero Element scanner3Shape filed the complaint in the United States District Court for the District of Delaware alleging patent infringement by Align’s iTero Elements intraoral scanner. The district court complaint seeks monetary damages and injunctive relief against further infringement.

Regarding the infringement complaint, Tais Clausen, 3Shape Co-Founder and Co-CEO said, “3Shape TRIOS has been named the best intraoral scanner by the industry for five years in a row1, and the most accurate in an independent ADA study2.

We invest heavily in our innovative technologies and over a third of our employees work in R&D functions. 3Shape’s intraoral color capture technologies are unique and fundamental to the TRIOS scanner’s overall design and high ratings among doctors. Therefore, we cannot allow competitors to copy our hard-earned technology breakthroughs or infringe our patents. Normally, because we believe in cooperation and openness, we would try to settle this directly and quietly with Align.

However, recent events and aggressive actions by Align, not only towards 3Shape but also actions affecting doctors using TRIOS with Invisalign, compel us to vigorously defend our intellectual property by filing this complaint in the federal district court.”

About 3Shape

3Shape is changing dentistry together with dental professionals across the world by developing innovations that provide superior dental care for patients. Our portfolio of 3D scanners and CAD/CAM software solutions for the dental industry includes the multiple award-winning 3Shape TRIOS intraoral scanner, the upcoming 3Shape X1 CBCT scanner, and market leading scanning and design software solutions for dental labs.

Two graduate students founded 3Shape in Denmark’s capital in the year 2000. Today, 3Shape has over 1,400 employees serving customers in over 100 countries from an ever-growing number of 3Shape offices around the world. 3Shape’s products and innovations continue to challenge traditional methods, enabling dental professionals to treat more patients more effectively. www.3shape.com

SOURCE 3Shape

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Baby Teeth Give Clues to Autism’s Origins, Detection

BY STEVEN REINBERG, HealthDay Reporter

A close examination of baby teeth is giving new insight into the roots of autism - and ways to spot it early.

The research suggests that the way infants metabolize two nutrients - zinc and copper - may predict who will develop the condition.

“We have identified cycles in nutrient metabolism that are apparently critical to

healthy neurodevelopment, and are dysregulated in autism spectrum disorder,” said one of the study’s lead authors, Paul Curtin.

His team has also “developed algorithms which can predict whether a child will develop autism or not, based on measures derived from these metabolic cycles,” said Curtin. He’s assistant professor of environmental medicine at the Icahn School of Medicine at Mount Sinai in New York City.

For the study, Curtin and his colleagues used baby teeth to reconstruct fetal and infant exposures to nutrient and toxic elements, in both children with autism and those without the disorder.

As kids develop in the womb and throughout early childhood, a new tooth layer is formed every day, the researchers explained. As each of these “growth rings” form, they contain an imprint of many chemicals circulating in the body, which provides a record of exposure.

Using lasers, the researchers sampled these layers and were able to reconstruct past exposures in a process similar to using growth rings on a tree to determine the tree’s growth history.

To determine the effects of abnormal zinc and copper metabolism on developing autism, Curtin’s team focused on baby teeth collected from Swedish twins.

Comparing children with autism to their typically developing siblings, the researchers found significant differences in copper and zinc levels in the teeth.

“These ‘biochemical signatures’ exist prenatally and at birth, opening up the possibility of developing a diagnostic test that could be administered in early postnatal life, years before current clinically based diagnostic tests are possible,” Curtin said.

To be certain of their findings, the researchers replicated the findings in three other groups, including non-twin siblings in New York and two groups of unrelated children from Texas and the United Kingdom.

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This study is the first to find a marker that can predict the risk for autism with 90 percent accuracy, the research team said, and may point to a possible new way of diagnosing autism.

One expert in autism said the findings were intriguing, but still in the early stages.

“Unfortunately, there are no immediate clinical implications [from this research] for early identification of autism spectrum disorder nor its treatment,” said Dr. Andrew Adesman. He’s chief of developmental and behavioral pediatrics at Cohen Children’s Medical Center in New Hyde Park, N.Y.

Adesman said there’s one big roadblock to the tooth test being used for early diagnosis.

The “analyses themselves were done after these teeth were shed by school-age children,” he noted. “This means that these types of dental analyses, even if the findings are replicated, won’t ever allow clinicians to truly predict autism, since the diagnosis is clinically evident by the time that children start to lose their baby teeth.”

But that doesn’t mean the new insights are a diagnostic dead end, Adesman said.

“They may lead to other studies that help to identify a prenatal marker that corresponds to the dental findings reported by these researchers -- and which would allow for an earlier diagnosis,” he said.

According to the U.S. Centers for Disease Control and Prevention, 1 in every 68 children in the United States is diagnosed with autism spectrum disorder.

The researchers said they also plan to use baby teeth to study the association of brain metabolism cycles with attention deficit hyperactivity disorder (ADHD) and other conditions.

The report was published online May 30 in the journal Scientific Advances.

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Building BusinessEstablishing a dental business is only half the battle in what has become a highly competitive profession. Maintaining success in the long-term requires a lot of hard work, clever thinking and fresh ideas, so utilising opportunities to help you implement all this is crucial.

However, this is sometimes easier said than done.

It’s useful to plan ahead so as to allocate time and resource to working on the business as well as in it. Whether you decide to dedicate a morning a week or a day a month, you’ll need this time to analyse your current business performance and ensure it continues to grow in the right direction. Here are a few key things to think about:

What are your USPs?

Your unique selling points (USPs) are what set you apart from other dental labs and these will be the focus of your marketing material. It’s necessary to consider what your business is known for, what its reputation is focused on and how you can further build on this or adapt it if required. Do you offer services not available from other labs in the area? Do you employ cutting-edge technologies that produce restorations of unmatched quality? Do you go the extra mile in order to offer an outstanding service to your clients? Whatever you do differently, identifying exactly what it is and maximising on it is important.

How do you compare?

Doing your market research on a fairly regular basis is necessary to understand how you compare. This might involve checking services and prices offered by competitors, or gaining inspiration from labs in other parts of the country who might be doing something you can incorporate within your own business. Knowing where you add value to your clients relative to other dental labs will help to demonstrate where you stand and may guide changes or expansion for the future.

How efficient are you?

This is not simply about reducing costs – although this might be possible with careful selection of products, bulk ordering where appropriate or making use of special offers and equipment maintenance packages from suppliers. It is also about streamlining processes to ensure an efficient workflow without any compromise on the quality of products generated. Maybe your lab needs a gentle redesign to improve ergonomics and make it easier for the team to complete work in a more timely manner. Perhaps your delivery process could be updated in order to reduce inefficiencies or online communication platforms could be better utilised to when liaising about cases with collaborating dentists. There are always ways of improving the daily running of your lab, and sometimes it is the smallest changes that have the greatest impact.

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Is your team capable of meeting demand?

Frequently checking that your technicians have the knowledge and skills they need to consistently deliver first-rate products is vital. If new technologies or materials are introduced, for example, the team may need training or the opportunity to undertake the appropriate courses. Any support you can provide with their on-going CPD will also be appreciated and will help to ensure a happy and productive workforce. If you wish to expand your business, bringing in people with new expertise and fresh ideas is a great way of refreshing the business and broadening the service available.

How wide is your professional network?

Dental technology can be a fairly isolating profession, with most technicians and lab owners remaining within the confines of the laboratory on a daily basis. This can make it difficult to meet new people and develop professional connections. Engaging with the wider dental community can help you build relationships with professionals who can provide valuable support. Not only can this network be utilised for ideas and guidance on enhancing the business, but it can also provide a pool of potential candidates for future team members.

Get involved

Attending educational events and conferences is a great way of engaging with the dental community and enabling you to work on all of the above. The Dental Technology Showcase (DTS) remains the premier dental lab event of the year and offers the perfect opportunity to interact with professionals from across the country. You can gain a wealth of information, industry updates, regulation advice and business inspiration throughout the packed two day lecture programme. You and your entire team can also learn from some of the biggest names in the field, developing skills and discovering new technologies while gaining hours of relevant, enhanced CPD.

For every lab owner looking to build their business and ensure success well into the future, there are several easy steps to take. Once you can distinguish yourself from other laboratories, ensure efficient workflows and create an effective network, you’re business will be ready to thrive.

DTS 2019 will be held on Friday 17th and Saturday 18th May at the NEC in Birmingham, co-located with the British Dental Conference and Dentistry Show. For further details, visit www.the-dts.co.uk, call 020 7348 5270 or email dts@closerstillmedia.com

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Upcoming Events

14th - 15th September 2018 The OTA conference, Nottingham.

For regular updates and more details go to:www.ota-uk.org

Meetings and Conferences

27th - 29th September 2018 British Orthodontic ConferenceQueen Elizabeth II Conference Centre, London

For regular updates and more details go to:www.bos.org.uk

19th - 22nd September 2018 Polish Society of Orthodontic Technicians (PTTO)For regular updates and more details go to:http://ptto.com.pl/

15th - 18th November 2018 German Society for Orthodontic Technician (GK)For regular updates and more details go to:www.gk-online.org

30th November - 1st December 2018 1st International Digital Orthodontic ConferenceFor regular updates and more details go to:www.adome.org

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Memories of an Old Codger 19 - Pay & ProblemsNineteen Eighty-Nine to the millennium was for me, the best years of Central Council(CC) where we were able to make a real difference in solving problems.

The process of constant change in the health services was on going and the Whitley Councils were drastically changing with committees being amalgamated. On 29 th September 1989, a new agreement was signed and Dental technicians found themselves in a new committee, along with 17 other technical groups employed on Professional &Technical B (PTB) pay scales.

Your grade and place on the pay scale would in future be decided by your local heath authority, using guidance set out by the PTB Council. I had been part of the long negotiations for this new grading structure and we had picked over every clause, making sure that all our relevant skills would be recognised as part of our submissions for the new scales. With this new agreement I could see lots of possibilities for us, getting away from the fixed position on pay scales that we had previously worked with.

Looking at the new agreement I knew that the employing authorities would offer us pay scales equivalent to those we were at present receiving, which was a Medical Technical Officer(MTO) scale 3 for a chief technician. I thought with a fight and appeal, I might get a MTO grade 4.

Cometh the moment, cometh the man and on this occasion his name was Harry Thompson, Chief Technician at Wexham Park Hospital and chairman of Central Council at that time. At this particular meeting delegates arrived and one was boasting that he had achieved a MTO grade 4. Harry opening the meeting, informed the Council that he would not accept anything less than grade 5 at his hospital and he expected to get the maximum discretionary grade points available, which was the highest grade available for the MTO grades.

So off we all went, suitably geed up to have a good go at a grade 5. I went home and started work on a job description as part of my submissions for the new grades and I must admit I was very pleased with the result. About a week later I received a phone call from Rod Snape Chief Technician at Peterborough Hospital and he asked me how I was getting on with my submissions. Rod said he wasn’t happy with how things were going and I sent him a copy of what I had done and a short time later Rod sent me his submission, which was less list like and gave more personal examples. I took on board some of Rod’s ideas and he also sent a copy of his submissions to Harry Thompson, who sent them off without alteration as his submissions for the new grade and as Rod said, it even included the same miss spelling he had made.

Harry Thompson was a pin sharp dresser, he oozed confidence and always carried around one of the first type of mobile phones, which as you will know from old films looked like a brick with a stumpy aerial attached and weighed about as much. Harry had an excellent working relationship with his hospitals chief executive which from my later experience, was the key to success with these and most negotiations. The first grade offer and I repeat, the first offer to Harry was a MTO 5 with 2 discretionary points, which he refused and later he achieved his third discretionary point. The precedent was set and none of us there at that Central Council meeting were surprised at his success, Rod Snape eventually achieved MTO5+2 but I had a long and tortuous fight to get there.

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Joint staff consultative groups were back then a requirement for hospitals and at the time Iwas the staff side secretary, and it was my job to raise difficult issues on behalf of the staff. I was always getting into arguments about agreeing the minutes and what had been agreed at the last meeting and the hospital secretary could never see why I felt it was so important. The atmosphere between us was less than cordial and this was how it was when I made my MTO grade submissions. I eventually had to initiate a grievance procedure to get an offer, which was a MTO 3 as I remember, this led of course to an appeal and I also applied for jobs all over the country and accepted one only for us to disagree about the salary and the offer was withdrawn.

So it came to my appeal and I asked Harry to represent me and he turned up with his mobile phone and plonked it on the table in front of the hospital panel and I achieved my grade 5 with a review for discretionary points to come.

Appeals were happening all over the country and we were constantly asked for help with submissions, this was OK as I personally sent them a copy of mine which would have been all right if they had read and amended them before submitting. Unfortunately, some did not read them which made thing awkward when they were asked questions.

I sat in on one appraisal where the young man was doing a good job working alone and things were going well at his hearing until we came to his health and safety responsibilities and the panel belittled him with questions he could not answer and they tried to stop my intervention. I eventually made the point that if there was a lack of knowledge there was no lack of responsibility and it was the hospitals duty to ensure that all staff should have adequate training in safety matters.

As the results of the regrading’s came in, it was my responsibility at the CC to collate them and we accumulated every result which made us the experts in the field. I was asked to attend a regional appeal where I was called as an expert witness and the appeal was being opposed by the appellant’s consultant which always made things difficult. I was grilled by the consultant and I put on my happy friendly face for my replies, but the data was the clincher. The appeals panel were very interested in the awards that other technicians had achieved. Grade MTO 5 was awarded and this was backdated 3 years including the extra holiday entitlement.

1993 saw the European Union regulations for Medical Devices introduced, we had a few years to formally comply and we were fed information from government departments to prepare us. The information was very vague when answering specific questions such as does every device need a CE mark to be compliant? Central Council Organised a seminar in 1997 which was oversubscribed and we arranged for an expert to talk us through the procedures we would need. The meeting was a success, but personally I felt it was full of generalisations and not specific to our technology, so I went back to the directive and working my way through it.

I listed what was needed by our technology to comply with the agreement. I designed conformity sheets, wrote out the safety sheets and the working protocols. Then they were all loaded into my new computer program which made the whole process quick and easy. Conformity printouts improved the presentation and record keeping in the lab and records and specifics were readily available. All sorts of things were now possible, each device could be easily tracked and patients had a printed sheet with all the information about their devices and how to look after them.

Everywhere at this time people were struggling with implementing the directive and I took a display presentation of how I was tackling the problem to the 1998 OTA conference that year. There were at least three displays on Medical devices that year, one was by a commercial firm offering help and Chris Bridle (Chairman of OTA) had been working on his own computer based model which was attracting a lot of attention. Chris was expounding the virtues of spreadsheets and he had the sense to use a Microsoft spreadsheet to implement the program which does not become redundant when computer operating system change.

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I had a few enquiries about selling my program but I did not feel I was in a position to support the program at distant venues, although a few technicians local to me used it until they retired.

Well I was getting to the end of my time as a technician but next time I will describe the bumpy start CC had with DTETAB and some of the problems they were facing.

John Windibank FOTA

Reference: - PTB Papers, CC Minutes

Central Council cc1990 left to rightR Winchurch, Birmingham : L Hall, Guys, London(with her back to the photo)

R Jackson, Reading : C Cowling, Bristol : H Thompson, Slough : M Cook, Swansea P Butter, Northampton : I Dawning, Rhyl : Rod Snape, Peterborough.

OTA Conference 1998Part of the Table Display

Medical Devices Computer Program how it is organised

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Thermoplastic materials in dental technologyThermoplastic materials have been used in aviation and space engineering for a long time. Owing to their high mechanical strength and low modulus of elasticity, they have begun to increasingly replace metal in many manufacturing industries too, particularly in those where metal has been the dominant choice until now. Implants for intervertebral discs, as well as hip and knee joints, are made of PEEK, a thermoplastic polymer. Four million implants have been fitted during the last 15 years with outstanding success. In recent years, thermoplastic materials have also been used in dental technology. This article discusses a number of common plastic materials that have become alternatives for use in the manufacture of non-metal telescopic dentures.

About 15 years ago, the first attempts were made, not without initial problems, to produce non-metal telescopic dentures. These dentures were made by injection moulding using a polyamide (PA) in the dental laboratory. A wax mould of the framework, bar and secondary crowns is made as an integral part, embedded in plaster in a flask and the wax boiled out. The plastic material, which is available in the laboratory as granular material, is heated in the injection moulding device and injected into the mould. After a period of cooling, which should not be shorter than specified, the prosthesis is removed from the mould and finished. Special milling cutters are needed because the material tends to become viscid when cut.

Very importantly, absolutely no metal must be entrained. If the denture were to cut by a tool previously used for cutting metal, minute metal particles would be incorporated into the thermoplastic material by the milling cutter. Friction would easily be controlled by expansion plaster. The good sliding properties and the high friction of the secondary crown particularly surprised us. When inserted, the secondary crown slides along the primary crown and is retained partly by clamping and partly by suction. Our patients found the good sliding properties and the light weight comfortable. The modulus of elasticity of PA is very low, which lends flexibility to the material. This gives the patient a sensation of a readily adapting denture, rather than a foreign body, in his or her mouth (Figs. 1–3).

The low modulus of elasticity, however, turned out to be the greatest drawback of the material. The moduli of elasticity of all plastic materials used for bonding are very high and two moduli as wide apart as these cannot be bonded reliably for a long time by any means available to dental laboratory technicians. As a consequence, many dentures develop cracks and spalls in the bonds after several months. In addition, the large pores on the surface of the denture led to discoloration, particularly in patients with an altered acid–base balance.

FPMA short while after PA, the industry launched a successor material with FPM. This thermoplastic fluoro-polymer offers some flexibility, but less than that of PA, however. The modulus of elasticity is margin-ally higher than that of PA, but distinctly lower than that of metal. Consequently, similar problems as those encountered with telescopic dentures of PA occurred.

PMMAWe have obtained good results with PMMA (Polymethylmeth acrylate). This plastic material is very hard and inflexible. Finishable in different colours, it is used for complete dentures and occlusal splints, as well as for long-term temporary dentures, crowns and bridges. The material is not susceptible to plaque, and discoloration is very inconspicuous.

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The moduli of elasticity of bonding materials and PMMA are similar; thus, cracks and spalls of bonds did not occur. Patients who had previously worn a telescopic prosthesis of PA or fluoropolymer, how-ever, complained that the denture of the new material was uncomfortable to wear. PMMA’s lack of flexibility gave patients the sensation of having a foreign body in their mouth (Figs. 4–6).

Unfortunately, denture breaks were reported after some time, particularly in free-end situations. Also, dentures not lined regularly and exposed to high force tended to break. We believe one reason for that is the fairly high modulus of elasticity, which makes the material somewhat brittle. The greatest problem, however, is that thermoplastic materials cannot be repaired. There is no way of repairing cracks or fractures. The only solution is to make a new denture.

PEEKPEEK (Polyetheretherketone) was first used for telescopic dentures about six years ago. In general medicine, it has been used for hip, knee and intervertebral disc implants for almost 15 years. According to German company Evonik Industries, as many as four million implants have been fitted and not a single case of proven allergy to that material has been reported. The modulus of elasticity of PEEK is similar to that of bone, with positive consequences for integration. This is one of the reasons that PEEK merits the attention of dental lab oratory technicians. Finally, there is a material with a hardness similar to that of bone, not as soft as PA or FPM plastics and not as hard as PMMA. These very rigid materials often cause dental technicians problems, for example with all-ceramic solutions for the upper jaw, where craniomandibular problems frequently arise.

PEEK is a very light-weight material with a long history of use in space flight. Non-conductive, it has been used in semiconductor technology for a long time. This property also offers benefits for use in the oral cavity.

The pharmaceutical industry uses PEEK in production. Parts in contact with the product are made of PEEK owing to its low discoloration and high resistance to wear and corrosion. Both properties are also very useful for dental technology.

PEEK is indicated for removable, as well as conditionally removable, prostheses. Therefore, bridges, crowns, telescopic dentures and attachments, as well as screw retained superstructures, can be fabricated.

The material has very good sliding properties and patients report that it is extremely comfortable to wear.

There are two different methods of manufacture. One is injection moulding and the other is CAD/CAM milling. The minimum thickness of telescopes is 0.6 mm. The minimum thickness of frameworks and bars is distinctly higher, but varies depending on the design and the size of the telescopic prosthesis, as well as the number of available telescopes. Generally, a PEEK telescopic prosthesis will be a little thicker than a metal telescopic prosthesis. It is an absolute necessity that the primary crown be made of zirconia, as abraded metal particles would otherwise collect under the secondary crown.

The veneer bond strength was tested in a study at the University of Regensburg, Germany, in 2012. In order to pass the test, a value of 5 MPa had to be achieved. Of all the veneering systems tested, PEEK scored 10 MPa and above and passed all of the bond strength tests. In other tests, such as discoloration and shear strength, it also achieved very positive results, confirming the suitability of PEEK for use in the oral cavity. When subjected to load at fracture tests, a PEEK bridge achieved 2,354 N and was far superior to a ceramic bridge, with 1,702 N. Hence, PEEK can withstand higher loads in the oral cavity than can ceramic material, and so wide-span telescopic dentures can be made of PEEK.

It is necessary when handling telescopic dentures of PEEK to apply ceramic guidelines because the material could otherwise be weakened owing to crack propagation. In addition, the prosthetic design

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must follow certain criteria. For example, a prosthesis without a transverse bar must always include a backing plate in the secondary part to provide sufficient stability. Dental technicians required to make non-metal telescopic prostheses should therefore receive sufficient training and instruction so that the required high-quality level can be maintained. Those who work with PEEK only rarely and who therefore lack experience are advised to have telescopic prostheses of PEEK designed and cut in a specialised laboratory.

Even in our laboratory, we have come across PEEK prostheses with cracks, but these have invariably been due to manufacturing mistakes. Prostheses made correctly exhibit no cracks. Cracks and spalls of the veneering of PEEK dentures can be found about as often as in telescopic prostheses of metal—that is, rather seldom.

PEEK is extremely resistant to plaque and inert to acids and chemicals; therefore, the denture can be cleaned with a chemical dental cleaner.

Friction is one of the most critical characteristics of telescopic prostheses. The friction of PEEK is very good and can be controlled ex cellently with expansion plaster. However, most important is that friction is permanent. We made our first telescopic prostheses of PEEK about five years ago and we have not observed any loss of friction in that time (Figs. 7–13).

ConclusionOur laboratory has the experience of having made over 300 non-metal telescopic prostheses over the course of 11 years. After initial problems and several tests, PEEK has finally proven a suitable material for telescopic dentures in the long term. Non-metal telescopic prostheses are in no way inferior to metal telescopic dentures, provided they are made professionally. On the contrary, the light weight, the high wear comfort and the absence of metal, in particular, are compelling arguments for dental technicians and patients alike.

Editorial note: This article was published in CAD/CAM international magazine of digital dentistry No. 03/2016.

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Thermoplastic Materials in Dental Technology CPD Questions

1. The modulus of elasticity of polyamide is very low, what benefit is this to the patient

2. What material is used to bond PA.

3. What are the drawbacks of wearing a denture made from PMMA.

4. What is the main advantage of a denture made of PMMA as apposed one made from a thermoplastic.

5. Name four indications for use of PEEK in the dental industry.

6. What are the two methods of manufacturing PEEK, for use in dental technology.

7. When subjected to load at a fracture test, which material ceramic or PEEK achieved the higher load.

8. What is one of the most important characteristics of a telescopic prostheses.

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OTA News CPD Submission Form - Summer 2018 Part One Please PRINT your details below:

Title: Prof Dr Mr Mrs Ms Miss

First name: Surname:

Address:

Postcode:

Telephone number : E-mail:

OTA Membership number : GDC Registration number:

Part Two Write in your answers below:

Question 1

Question 2

Question 3

Question 4

Question 5

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Part Three Evaluation - we value your feedback regarding the value of OTA News to readers:

OTA Members – please print out and post to the address below or download MS Word version of the form from the OTA website and email the completed form and feedback to: otanews.cpd@gmail.com (please note that a valid email address must be supplied for issue of free CPD certificate).

Non OTA members - Please return your completed form together with a cheque payable to the Orthodontic Technicians Association to: Mrs Andrea Johnson, Montagu Hospital, Adwick Road, Mexborough, S64 0AZ.

Question 6

Question 7

Question 8

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Verifiable CPD with OTA News The questions are designed to help you make the most of OTA News by reflecting on a range of articles. Submit your answers by post or email together with your payment (if applicable) and receive a certificate of verifiable CPD.

The CPD questions are based on a range of articles in the publication covering a variety of topics. Read the articles and then answer the multiple choice questions. The pass mark is 50%; if you score less than this you will need to re-submit your answers.

Verifiable CPD

In order to meet the requirements for verifiable CPD we will list the learning aims, objectives/out-comes. Feedback is encouraged by post or email to the editor.

How much does it cost?

If you are an OTA member and agree to receive your certificate via email then it is free otherwise a charge of £5 will apply to cover admin and postal costs.

The fee for non-members is £10 (or £20 if a posted hard copy certificate is required) please note that we can only accept cheque payments.

Learning aim

The questions are designed to help dental professionals keep up to date with best practice by reading selected articles in the current edition of the newsletter (technical, personal development, business etc.) and checking that this information has been retained and understood.

Learning objectives

After completing the questions, you will have been able to confirm or reinforce your knowledge retention of the included articles.

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Keeping you informed about ECPD The enhanced CPD scheme is designed to support dental professionals to gain maximum benefit from CPD activities. The plan, do, reflect, record model encourages you to proactively think about your professional needs, field of practice and the Standards for the Dental Team before embarking on CPD activity.

In this way, the activity becomes more meaningful and applicable to areas that you have identified to maintain or build on.

Plan The personal development plan (PDP) is used to help you identify your CPD needs for your cycle. You will create a plan for maintaining and developing your skills and knowledge within your field of practice, and how this relates to the GDC’s development outcomes1.

Please refer to section five for more information on the PDP, field of practice and development outcomes. Do You will identify the verifiable CPD activity that best meets the professional needs set out in your PDP, and then complete your CPD activity consistently throughout your cycle.

You might find that your field of practice or needs change, and you will need to adjust your plan and activity accordingly. Reflect Reflection is an important process for you to evaluate the impact of your CPD activity on meeting your professional needs for maintenance and development.

Taking some time to review and reflect on your activities allows you to assess what benefits you have gained and how you have implemented your learning. After reflecting, you may find that you need to adjust your PDP and activity. Please refer to section 5.6 for more information on reflection.

Record You need to record what CPD activity you have completed. A complete CPD record includes your log of activity with development outcomes linked to each activity, your personal development plan, and the evidence you have collected from each activity. You must also submit your annual statement each year to let the GDC know you are keeping up with the requirements of the scheme.

You will be notified to make your CPD statement when you get your annual renewal notice, but you can update your statement at any point in the year on eGDC.

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The OTA welcomes any relevant/interesting articles from our members to be used in the Newsletter and if suitable our website too.

Articles submitted could be of general interest to the dental/orthodontic community or may be supplied for use as verifiable CPD such as technical walkthroughs etc, in which case you would need to also supply along with your article 10 questions to be posed on the article itself.

The word count for articles is not critical so long as it is an appropriate length for the article but some; if too long may be split into two parts and part two published in the following newsletter. This is subject to the editor’s discretion.

Font: Calibri Size 12 - subheadings boldSize 12 - main body

I hope I have provided all the information you require but if there is any other questions please do not hesitate to contact me at newsletter@ota.org

Kind Regards,Andrea.

OTA Newsletter Editorial Team

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Portfolio Name Telephone Email

President Rye Mattick 0191 2825015 president@ota-uk.org

Executive Committee:

Chair Andrea Johnson 01709 649077 chair@ota-uk.org Publicity Co-ordinator

Treasurer/Vice Chair Daniel Shaw 01246 51 2104 treasurer@ota-uk.org Acting Secretary Edward Mapley 02920 416899 website@ota-uk.org Website & VLE Editor, BSI representative, Awards, Student Sponsorship, education officer

Acting Membership Secretary Jennifer Alexander Membership@ota-uk.org& Social Media Co-ordinator

Council Members:

Conference Programme James Green 020 7829 8614 jamesgreen@nhs.net and Proceedings Editor Advertising & Sponsorship Grace Chandler chan11181@hotmail.com Co-ordinator Co-opted Council Member Neale Price 0131 657 5906 neale.price@sky.com Co-opted Council Member Simon Green 07791116059 newsletter@ota.org Newsletter Editor & Commercial Laboratory Engagement

Council Member Jinesh Patel 07545896790 Jineshpatel1088@gmail.com

Council Member Jennifer Dunnett 01312295967

Directory of OTA Officials

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Directory of OTA Officials

RYE MATTICK ANDREA JOHNSON DANIEL SHAW

JENNIFER DUNNET EDWARD MAPLEY JAMES GREEN

JINESH PATEL GRACE CHANDLER JENNIFER ALEXANDER

NEALE PRICE SIMON GREEN

News & Features

The Orthodontic Technicians Association12 Bridewell Place, London, EC4V 6AP Website: www.ota-uk.org