Combing Laser & Digital Dentistry

Cohan Rajan discusses combining restorative treatment using digital dentistry with the benefits of dental lasers 

Figure 1: Initial presentation, broken crown, isolation with Isolite for preparation and scanning 

We are lucky to live in the era of digital dentistry and the technologyavailable to us is ever expanding. One of the areas seeing the greatest advancements is that of intra oral scanners (IOS) with new machines coming to the market all the time.

Figure 2: After preparation and troughing to expose margins with Waterlase 

I have used various iterations of the Cerec system for over 15 years now and having been in the same clinic for that time, I have been pleasantly surprised with the longevity of the restorations produced by this system, so I’m a big fan of IOS and digital dentistry. 

Figure 3: Try-in to check fit and occlusion before sprue removal and crystallisation 
Figure 4: Fit with PTFE isolation of adjacent teeth


When deciding on what technology to invest in for our practices, the key deciding factors should be the benefit to our patients, the benefit of a better and more effective workflow and of course, the benefit to the bottom line. 

A good example of this is, recently, I was convinced to get an iTero scanner for the Invisalign treatments we offer. I have found that the way the iTero scanner works, and the user interface really got my team into scanning in a way that is quite remarkable; to the point that I am in the process of building a scanning room where patients will routinely be scanned as a way of taking digital study models that can then be compared with new scans at the next visit. 

The patients benefit from digital study models in real colour which is great for patient education, the hygienist can check for recession, I can check for tooth movements and wear and it is all done quickly and efficiently with minimal costs to the patient. Of course, it works seamlessly for Invisalign too with my assistants doing the scanning. By contrast, they would never use the Cerec. Get the right IOS for the 


Cohan graduated from Barts and The London School of Medicine and Dentistry in 1998 finishing his studies there with an MSc (Gerodontology) in 2000. His passion for better treatment through the application of technology lead him to set up a fully digital private squat in 2003, Dental-Spa, in the West End of London where he is still in practice. From then, Cerec and Waterlase have been his go to technologies but recently he has also integrated iTero and CBCT into practice. 


When it comes to IOS applications for restorative work, we need to consider what the ideal scenario is for the scanning. The main issues with scanning in the oral cavity are moisture contamination, either of the scanning camera head or of the area to be scanned. 

With the scanners becoming so accurate that we can use them for implant work as well, we should now consider how we can manipulate the hard and soft tissues to achieve the clinical result we aim for. The application of lasers and CBCT in relation to implants has been covered elsewhere, so I will not cover that in this article. 

For the patient, what is most important is as little as possible post-operative inflammation and pain; we have the technology to give them that outcome. This is also a great practice builder as happy patients refer their friends and family and they also love being treated with lasers. 


I have been using the Waterlase all-tissue Erbuim dental laser from Biolase for over 10 years now and my laser is still going strong. Like any dental equipment, it has to be serviced as stipulated by the manufacturer. That is an excellent return on investment by any standards and although there is a computer in it, it is not stressed and performs flawlessly every time. There was a learning curve for me and my team, but it was really not difficult, and the training support was really good. 

One of the key benefits to the tissue is that the laser does not destroy as many cells when compared to diode lasers, the scalpel and the worst offender, electrosurgery. As the depth of the cut is from only three cell layers, there is reduced histamine release with little to no post-operative inflammation and zero scar-tissue formation. This is particularly important in the aesthetic zone when we need the soft tissue to stay where we want it. The benefit of no post-op inflammation is self-evident. I use the Waterlase extensively when doing same-day smile makeovers for patients from overseas and I can be confident that the pink/ white balance will be stable and gum level is where I want it. 

This is another key benefit of the Waterlase as it can be used to trough around margins for exposure of preparation margins prior to prepping and also scanning. It does so in a bloodless manner as there is little to no bleeding when used on soft tissue but without the carbonisation of the tissues. 

The primary application of the diode laser in my practice is photo-biomodulation (PBM) where it is commonly used to aid healing and reduce inflammation post operatively and I have found it especially effective in my dental implant work


When working with the Waterlase, magnification is very important, and I use a dental microscope usually at 16x magnification. This brings with it a whole new level of detail that can help us to provide better dentistry. With IOS our tooth preparations are blown up to a whole new level of detail right in front of us on a screen, so we need to strive for fantastic margins that are also free of contaminants and blood. 

Figure 5: Removal of excess resin; excellent visualisation of margins with troughing

The case study pictures illustrate a typical digital workflow for a Cerec Emax restoration in my practice, which will be booked for two hours in the appointment book. I charge a modest fee separately for the laser treatment, but I do tend to use it for almost every prep in the posterior region as often, by the time a ceramic restoration is indicated, I usually find there will be just sub-gingival margins which will need to be exposed prior to prep and scanning. 

To deal with moisture contamination I use Isolite (now Zyris) for preparation, scanning and fit and find this system to be well tolerated by roughly 80% of patients. It also provides a field that is comparable to rubber-dam isolation in terms of moisture control. 

Figure 6: Final check for excess material. Note how troughing exposes margin but this will rebound

You can see from the pre-scan photo (Figure 2) how the Waterlase troughing leaves no bleeding and that continued through to the removal of excess luting at the resin stage, as I find that the bleeding is minimal after using it on soft tissue. This is optimal when combined with IOS. I use a radial firing tip in contact mode so troughing a tooth like this is the work of a couple of minutes. For me, the benefit of the Biolase ecosystem is the wide variety of tips available for the Waterlase which really broadens the applications of lasers in dentistry and a really enthusiastic group of peers when you go to one of their meetings. 

The onwards march of digital dentistry is something that I celebrate and enjoy using in my practice and Waterlase is really an integral part of my workflow that I use every day to help me provide the best standard of care I can for my patients. I can’t imagine practising without it and it’s such a fantastic tool that I have no hesitation recommending it to everyone using or considering an IOS. Take the leap and invest in your dentistry! 

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5 Years Dental Phobia

We understand all about dental phobia and the anxieties surrounding visiting a dentist which is why we have been proud members of the dental phobia association and this year we have reached the 5 year mark of continually providing the best support regarding patients with dental phobia.

There are many different levels of phobia and anxiety surrounding dentistry and here at Dental-Spa we are empathetic to our patients needs and will continue to do so into the future.

Dr Rajan 5 years certified dental phobia

If you struggle with dental anxiety and want to talk to us please feel free to call our team who are all well trained and here to help you get the treatment you need.

A Younger Smile For An Older Lady

Here at Dental-Spa London we love bringing people their confidence back, watch our short video on how we brought a younger smile on an older lady in just 3 hours using non invasive techniques.

If you want to bring you confidence back, why not speak to a member of our dental team today

Digital Symposium & The Role Of Minimally Invasive Dentistry

Dr Cohan Rajan was invited as a KOL (Key Opinion Leader) for this panel at the premier Digital Symposium 2017 to share his expertise and experience on the subject of the use of CEREC and Waterlase in the role of Minimally Invasive Dentistry. Check out the video below and feel free to get in touch with the clinic if you have any questions regarding this or any other cosmetic dentistry service why not speak to a member of our team today.

Invisalign vs Normal Braces

If you are considering Braces or Invisalign for yourself or family member, it can be quite difficult knowing which one to choose and you may have many questions. You want to know which is more effective, what is the price differences and which is best for long term care of your teeth. Here we will take a look at both Braces and Invisalign and compare the differences.


Braces are typically metal brackets which are glued to your teeth. They are held together by wires and special rubber bands. The wire and brackets of the brace are pressed against the teeth, they support any slight nudges or movements of the teeth. This helps enable the correct aligning and straightening of your teeth. Braces help straighten your teeth, close any gaps and fix and problems with crooked teeth. The biggest downside of traditional braces is the unsightly metal and possible stigma of wearing them. Metal braces can often make people feel very self conscious and embarrassed to smile. Another patient annoyance of metal braces is that they are unremovable once they have been fitted; up until the duration of treatment has ended. The cost of traditional braces is between £1500-£2500.

Key facts for Traditional braces:

  1. Have to brush wires and brackets
  2. More effective for complex issues
  3. Unsightly
  4. May be uncomfortable (Cause pain or sores from the wires)
  5. May have difficulty eating certain foods
  6. Unremovable
  7. Cheaper than Invisalign


Invisalign is the brand name of a clear dental aligner. Invisalign can be used for a variety of different dental treatments such as: overlapping teeth, wide gaps in teeth, cross bite, overbite, relapse after tradition braces and bite irregularities. Invisalign braces have been dubbed ‘invisible braces’ as they are not very obvious on your teeth compared to traditional braces which make you appear to have a mouth full of metal. Invisalign braces are removable and can be taken out when eating, drinking and brushing your teeth. This makes life a lot easier for many people as they no longer have to worry about food getting stuck in the braces or brushing over the wires. The downside of Invisalign as that although it can correct most teeth complications, it cannot correct all of them. Some conditions such as: changes in back tooth bite, uprighting root movements, vertical movements and rotating cylindrical teeth can only be corrected by traditional metal braces. The cost of Invisalign braces is between £2500-£4500.

Key facts for Invisalign braces:

  1. Removable
  2. More hygienic
  3. Makes you more flexible to eat certain foods
  4. Almost invisible (Cosmetically pleasing
  5. No discomfort from wires and brackets
  6. Cannot correct certain dental problems
  7. More expensive than traditional braces

There is quite a tight race between traditional braces and Invisalign but Invisalign slightly takes the lead when it comes to advantages. Both choices are great for straightening your teeth and fixing certain problems. Invisalign is perfect for teenagers and those who are likely to be self conscious, though it’s wise to remember that they are not suitable for everyone and all conditions. Your dental practitioner will advise and inform you of the best available options for your teeth.

If you are interested in looking in to Invisalign further and are in the London area, then why not check out our Invisalign page where you can get more information and feel free to book a free consultation today.

Teeth Whitening: Why it should only be done by a dentist.


There a whole range of teeth whitening products available in stores and online. The prices range from £5 to a few hundred pounds. These over the counter teeth whitening products promise you that your teeth will be several shades whiter within a few applications but this has not been proven and the products may put your oral health at risk. Some beauty salons offer a teeth whitening service but this is illegal, teeth whitening should only be done by a registered dentist or a by a regulated dental professional such as: a dental hygienist, a dental therapist or on a prescription which has been prescribed by a registered dentist.

The effects of DIY whitening kits can range from mild to severe damage to your teeth. Here are some of the side effects that over the counter whitening products can produce.

Nerve Damage

Teeth whitening products can cause damage to the nerves in your teeth. With the harsh chemicals, bleach and poorly fitted mouth guard nerves are susceptible to getting damaged or infected. For someone who has deep cavities, whether they’re aware about it or not, the bleach can have a direct route into the blood vessels, bone and root of the tooth. The bleach can cause irreversible nerve damage which will cause a very bad toothache and may require antibiotics and/or extraction of the tooth.

Upset Stomach

Many DIY bleaching kits have very high acidity. As well as damaging your teeth, the bleach can give you an upset stomach when swallowed. Many over the counter kits come with a standard sized mouth guard. The mouth guard is poorly fitted, therefore it is very easy for the bleach to be swallowed. This causes burning, discomfort and nausea, continual swallowing of the bleach if agents can irreversibly damage the lining of your stomach.

Tooth Erosion and Sensitivity

The chemicals in tooth whitening kits can be harsh on your teeth. The main ingredients are Hydrogen Peroxide and Bicarbonate, these are very abrasive. These chemicals will start to erode the enamel on your teeth The enamel is the shiny coating which covers your teeth but it is not just for cosmetic purposes. Enamel is there to protect your teeth from decay, if the enamel becomes eroded, it is more likely that tooth decay and discolouration will happen. This means tooth whitening can become harder to fix  in the long run. This can happen more quickly in some people than others. The tooth erosion can also lead to sensitive teeth which will cause you discomfort when brushing, eating and drinking certain things.

Gum Disease

Continued use of over the counter teeth whitening kits can cause extensive damage to your gums. High concentrations of Hydrogen Peroxide can make your gums become infected which can have severe consequences on your

Some Recent Before & Afters Cosmetic Treatments

As being one of the premier cosmetic dentists in London providing Invisalign services and a multitude of others, we thought we would be display to you some recent cosmetic dentistry treatments and their outcomes with you. You can really get a feel for the kind of things people want to change with their smile and their teeth and it is not always about teeth whitening or straightening teeth.

First up we have a Enlighten Teeth Whitening client with two E-Max Veneers, you can see from the pictures of the before and afters below how the veneer and colour change has transformed his smile.

teeth whitening with two veneers

The next customer was a bit unusual for us, but no less complicated. We treated a customer that wanted a tattoo removal from the gum line using the latest in waterlase techniques which meant literally no pain or discomfort. See the before and after pictures below.

Waterlase Tattoo Removal From Gum

This customer below had his smile transformed using the same day CEREC E-Max 6-unit smile makeover technique that has made us so popular in London for teeth whitening services. The transformation of all the teeth, cleaning of the stains and has brought a rejuvenated smile and air of confidence back.Teeth Whitening Same Day

This client wanted her bottom and top teeth fully whitened using the Enlighten Teeth Whitening and CEREC E-Max Bridge, as you can see she already has great teeth that are well aligned, but the teeth whitening really makes them stand out.

CEREC Teeth whitening London

This customer, you can really see the difference. He wanted to totally transform his smile so we added 12 Unit dental veneers along with a full same day smile makeover to clean them from the start. This really is a great before and after and shows you want can be achieved.

Dental Veneers London


Dental Spa BDA Good Practice Celebrating 10 Years

Sometimes words are not needed, we are happy to announce we are now Gold members with the BDA and are proud to be celebrating 10 years under the scheme. As one of the premier cosmetic dentists London has to offer, we take pride in everything we do and our patients and their welfare are so important to us. You can read more about the BDA Gold Membership and what it takes to achieve this by visiting the webpage.

Dental Spa Good Practice and Gold Member for 10 years

Why Choose A Smile Makeover?

Almost everyone has had a makeover, whether it be a hair makeover, makeup, clothing style or professional tan. So why not have a smile makeover? The first thing people notice about about you is your smile. The importance of your smile cannot be ignored, it defines who you are and can leave a lasting impression on people around you. A smile plays a key role in your appearance and builds your confidence and self esteem. Improving your smile can be one of the best long term investments you can make, it can highlight your personality and transform your appearance, for a brighter quality of life.

Which Smile makeover is right for me?

Everyone’s smile is different and everyone has different needs. We design our treatment to suit each individual client. Below is a list of treatments we provide to create your perfect smile transformation.

Teeth Whitening

If your teeth are discoloured or stained, it can leave a negative impact on your self esteem. For a brighter, cleaner smile, we can provide a professional teeth whitening service to suit your needs. We currently offer two different options for teeth whitening, Zoom! Laser Teeth Whitening and Enlighten Deep Bleaching Protocol. Both of these treatments have had outstanding success in recent years and have had excellent review in the press. Whiter teeth can improve your confidence around others and will be noticed by friends and professionals alike.


A chipped tooth, gaps or cracks can be irritating and unsightly. Veneers can help fix them problems and create a straight natural looking smile. They can also improve the shape, position and colour of your teeth. Veneers are made with a thin layer of porcelain which cover the front of your teeth, or a thicker section to replace gaps and cracks. The shades of porcelain Veneers are carefully chosen to improve your discoloured teeth (or a single tooth) You can also choose the same shade as your natural teeth to fill in gaps. Veneers are thin and held in place by a strong adhesive, this makes them look very natural and healthy.

Dental Crowns

Damaged or decayed teeth may be corrected with the use of dental crowns. A dental crown can be a last resort for badly damaged teeth before otherwise being extracted. A crown is a tooth shaped covering ‘Cap` that is placed over the tooth, it helps to restore the strength, position or shape of the tooth.

Invisible orthodontics

Teeth straightening, also known as Orthodontics or Braces, usually involve metal wires and brackets. These can be very uncomfortable and may make you very self conscious. It is not uncommon to be teased and called ‘Metal mouth` because of your unsightly metal braces. Invisible orthodontics (Invisalign) have proved to be extremely popular and are a perfect solution to those who want to straighten their teeth but don’t have to worry about the appearance of wearing metal braces. The clear braces and aligners are made of a translucent material which are almost invisible to the naked eye. Make your smile a magic trick to be proud of, Hey presto! And your invisible straight smile will impress everyone around you.

Dental Implants

Lost or damaged teeth can be devastating and make you feel a like a real part of yourself is missing. Missing teeth don’t only affect appearance, they can also impact your speech, chewing habits and the way you eat. Dental implants can replace your missing tooth and make you feel whole again. A dental implant is a fine titanium rod which is used to replace the root of the missing tooth. The implant will be create a healthy natural looking replacement to your smile and the shade will be chosen precisely to match your existing teeth

Facial rejuvenation

A beautiful smile does not only involve your teeth, your skin can also affect your appearance. With facial rejuvenation, you can revive your youth by reducing the appearance of fine lines and wrinkles around your mouth and eyes. Facial rejuvenation may sound daunting to some but rest assured, the treatment is safe and non surgical. Facial rejuvenation can be performed using different methods, Restylane (fillers) or Botox. Both treatments result in younger-looking, radiant skin; giving you that youthful smile you’ve always dreamed of.

General Dentistry

Your oral health is the most important aspect to maintaining your healthy looking smile. From oral hygiene (teeth cleaning) to fillings, we have a range of treatment to keep your teeth healthy and functional.

Whatever your reason or choice for your smile makeover, here at Dental-Spa, we have the best health and cosmetic treatments to suit your needs. We offer consultations, assessments and membership plans. Look forward to your brighter smile and brighter future.