PreViser FAQs


What is PreViser?

PreViser is an easy to use online tool that assesses the risk of oral disease, the severity of perio
disease and restorative needs and the preventive options or treatment that may be required to
secure a patient’s oral heath

What do you mean by ‘risk’?

A risk score describes the likelihood that without appropriate home and professional preventive care, a worse condition will develop at a future date.  More specifically tooth decay risk predicts tooth decay or breakdown of an existing restoration and therefore the future need for restorative need or extraction.  Gum disease risk predicts an infection of the gums or bone loss which means periodontal treatment or extraction will be needed

How do I set up PreViser?

PreViser is an online tool that is accessible from any device that can access the internet. No software download is required. Simply request your referral code to activate the single account for your practice, create a username and password and set the encryption code that will protect your patients’ identities.

What internet browser should I use?

Google Chrome or Firefox will work best as will Safari on an iPad. All versons of Internte Explorer will be slower than these other browsers and versions earlier than IE8.0 will not work at all.

How long does it take to do a PreViser assessment?

You have the choice of completing a comprehensive assessment or one of three individual assessments perio, caries and oral cancer. If you choose to do the comprehensive report, then the other reports are simultaneously generated. The non-clinical elements of the comprehensive assessment can be completed by your patient in reception before their appointment to save time and to get them thinking about their risk factors.  Once you are familiar with filling out the simple online form, a comprehensive assessment will take around 5 minutes. A perio assessment should take less time.

How often should I perform a Risk Assessment on a specific patient?

You can perform Risk Assessments on a patient as often as you wish. You might consider making it an annual part of the patient’s care routine. Also, if the patient has a change in health or some event affects their oral health, their risk score may change, so you may wish to incorporate a new Risk Assessment in connection with any oral health change or major treatment.

Is there any reason to use PreViser on all patients?

We believe so.  Our published research indicates that it is very difficult even for experts to correctly identify oral disease risk.  All patients who currently have moderate to severe periodontal disease were at one time healthy and our aim should be to identify the disease process before it becomes obvious as by that time, damage has already been done.  Additionally, when patients are exposed to PreViser scores they have information that helps them understand the value of professional dental care, and the consequences of avoiding it.

How does a hygienist or therapist use PreViser?

PreViser is ideal for use by hygienists or therapists because it provides direct personalised biofeedback for patient education and motivation. Hygienists are key to educating and motivating patients about common oral diseases and empowering patients to perform home care. PreViser builds upon these principles of empowering patients by providing validated, evidence based risk and disease scores.

What are the medico-legal ramifications of using PreViser?

In using PreViser you have evidence of having completed a comprehensive examination; your assessment of the patient’s risk and disease status, and of communicating this together with suggested preventive actions in writing to your patient. A well-informed patient is your best way of reducing medico-legal risk.

When I use PreViser, am I complying with the Data Protection Act?

PreViser is designed to be in compliance with the Data Protection Act in that all data which is transmitted has been de-identified. We have confirmation in this regard from the Information Commissioners Office. However it is clearly your responsibility to ensure that data procured with the PreViser is secure in your practice.
When you set up PreViser on your computer, you will be requested to create an encryption code that only you should know. Do not lose this encryption code because it cannot be retrieved by PreViser or OHI Ltd. This code encrypts patient identifiers before they leave your practice so that all data we receive is anonymous.

How can I save a report to my files or email it to a patient?
  • You can print directly from the web page.
  • To save the report electronically, either print and scan to your practice management software, or print to pdf
  • To print to pdf from Chrome, select Print then change the Printer Destination (second option) to Save as PDF. Press Save and you will then be asked where you wish to save the file to.
  • If you are sending the pdf to the patient, please confirm with them that they are happy for their personal data to be emailed.


Perio Risk Score

The periodontal risk score indicates the probability that the patient will develop periodontitis, or if currently diseased, will worsen over time without appropriate care. This clinically validated score (see research page)can be correlated to loss of teeth over time

How is the gum disease score calculated?

The gum disease score ranges from 1-100.  it is calculated from pocket depth, radiographic bone height and bleeding on probing for each sextant.  Five categories of the disease are defined (healthy, gingivitis, mild, moderate and severe periodontitis).

The following table indicates how the pocket depths and bone heights broadly drive the health grading by the algorithm:

Radiographic bone height distance from CEJ
<2mm 2-4mm >4mm
Pocket Depth 5mm Health or gingivitis Mild perio Moderate perio
5-7mm Mild Perio Moderate perio Severe perio
>7mm Moderate Perio Severe Perio Severe


The following table shows how the scores from 1-100 are calculated.  The algorithm is sensitive to minor changes – even small improvements on the What’s Changed graph are to be celebrated with your patient.

Categories of gum disease

Score range



No sextant has gingivitis or perio


1 or more sextants have gingivitis and none have perio
Mild periodontitis


1 or more sextants have mild perio


≥ 40% of sextants has mild perio
Moderate periodontitis


1 or more sextants has moderate perio


≥ 40% of sextants has moderate perio
Severe periodontitis


1 sextant has severe perio


≥ 20% of sextants have severe perio


≥ 40% of sextants have severe perio


≥ 50% of sextants have severe perio
Caries risk score

PreViser’s caries risk score provides a projection of the likelihood that without appropriate home and professional care, including the management of risk factors, patients will experience new carious lesions or breakdown in existing restorations. It is based on CAMBRA, ADA , AAPD risk factors, and as such, represents a “Best of Breed” approach to caries risk assessment.

Restorative Needs Score

The Restorative Needs score shows the patient what their current treatment needs are. The score is quite simple, but also very powerful. A score of 1 represents a pristine dentition without carious lesions or restorations. A score from 2 to 9 represents a restored dentition with no current lesions or defective restorations. A score from 10 to 100 indicates increasing needs as measured by untreated lesions or defective restorations.  The ten’s digit reflects an increasing percentage of teeth that need restorative treatment and the unit’s digit reflects an increasing percentage of teeth which have previously been restored.


PreViser inputs

Do I record pocket depths around implants?

No, you should not use measurements of pocket depth for implants in data entered for the perio assessment.


How is primary caries defined?

Primary caries is caries occurring in a previously un-restored tooth surface.

Should I always exclude 3rd molars?

If 7s are missing and 8s are present, count these as 2nd molars.

Do I need to measure radiographs?

The following table will give you some useful guidance on how to interpret your radiographs quite simply for PreViser. This has been shown to be more accurate than trying to actually measure bone heights on your radiographs:

Input  Visual impression of radiographs
Less than 2mm Normal bone height
2-4mm Between normal and excessive
Greater than 4mm Excessive bone loss
Are e-cigarettes considered a risk factor?

Most of the adverse effects we see in smoking are un-related to nicotine or cotinine, more to the tar particulates and other soluble factors like acrolein and thiocyanates.  

There is no current evidence that the use of these smoking cessation aids has an impact on oral cancer or perio risk.  


Do I have to take radiographs for an assessment?

No.  Follow you normal protocols.  Radiographs taken within the last couple of years should be sufficient.