Quality Resource Guide –
Periodontal Risk Assessment in a General Practice 2nd Edition
www.metdental.com
Page 2
Periodontal Risk Assessment
in General Dentistry Practice
Development of a Risk Assessment
Model for Periodontal Disease in General
Dentistry Practice:
A number of risk
assessment models for periodontal disease have
been developed over the last 15 years using data
from studies that analyzed the risk for periodontitis.
These models use 5 to 20 risk factors/indicators to
assess the risk of future disease progression.
9
Page
and colleagues (2002) developed a computer-based
risk assessment tool termed the Periodontal Risk
Calculator (PRC).
11
The PRC uses eleven factors/
indicators (age, diabetes, smoking, local factors,
various measures of existing periodontitis) to
determine a patient’s risk profile. A patient is placed
into one of five risk categories ranging from low risk
(score of 1) to high risk (score of 5). The PRC has
demonstrated an ability to predict the progression of
periodontitis.
12
The algorithms used in the PRC were modified for
use in another computer-based risk tool named
the Periodontal Assessment Tool (PAT). The PAT
provides a risk score and a proposed periodontal
treatment plan. The PAT demonstrated the ability
to reliably predict future bone loss and tooth loss
in a 15-year longitudinal study (Table 2). As data
in Table 2 illustrates, within 15 years, a patient with
a risk score of 5 is approximately 7.6 times more
likely to lose a tooth than a patient with a risk score
of 2. Because of the proven validity of the PAT in
longitudinal studies, it has become the standard to
Table 2
The Validity of the Periodontal Assessment Tool (PAT) used at Baseline to Predict
Percent Bone Loss and Percent Tooth Loss at 3 and 15 years.
Risk Score
Percent of Bone Loss
Percent of Teeth Lost
3 Years
15 Years
3 Years
15 Years
2
0.7%
3.3%
0.5%
3.1%
3
1.0%
4.0%
1.6%
8.4%
4
1.3%
5.1%
2.1%
11.1%
5
2.5%
6.9%
4.9%
23.7%
Note:
Because of the small number of subjects with a risk score of 1, no data from that group is
presented.
Data from Page, et al.
12
Risk assessment is commonly used in medicine to
determine whether a patient warrants intervention
or increased monitoring to prevent a disease,
or disease-related event, from occurring. The
cardiovascular event risk profile developed from the
Framingham Heart Study is one of the best-known
risk assessment tools used in medicine. A patient’s
age, gender, cholesterol, HDL level, blood pressure,
blood sugar, and smoking history are placed into
an algorithm that calculates an individual’s risk for
future cardiovascular disease. Although it is not
ideal, this risk assessment tool has been used to
determine whether preventive interventions should
be implemented.
Risk assessment for periodontitis uses risk factors/
indicators to predict the likelihood of a patient
experiencing active disease in the future. It differs
from diagnosis and staging of periodontitis based
solely on historic measures of periodontal destruction
such as probing depth, clinical attachment loss and
radiographic bone loss. The key to developing a
clinically useful risk assessment tool for periodontitis
is identification of a minimal number of easily
obtained risk factors/indicators that accurately
predict the future likelihood of disease progression
in a specific patient.
Risk Indicators for Periodontitis
Because of the complex nature of periodontitis,
a large number of factors/ indicators have been
associated with increased risk for periodontal
disease progression.
8
The data supporting the use
of a specific risk factor/indicator are often based
on a cross- sectional relationship of the risk factor/
indicator with the presence of periodontitis. Relatively
few longitudinal studies have been performed that
examine the ability of a risk factor/indicator to predict
future attachment loss.
8
A summary of important risk factors and indicators
are presented in Table 1. Histories of periodontitis,
smoking, and/or diabetes, and the current level of
gingival inflammation, are considered major risk
factors for, or indicators of, future progression of
periodontitis. These patient characteristics have
been used to develop tools to evaluate risk for
periodontal disease progression. Other risk factors/
indicators may be used to modify and improve a risk
assessment tool’s ability to predict active disease.
However, for a risk assessment tool to be useful
clinically, it should use a minimal number of readily
obtainable clinical data.
9-10
which other risk assessment tools are compared.
However, the use of the PAT is limited by the
proprietary nature of its algorithm, which requires a
fee per use, and by the quantity of information that
must be inputted.
Another commonly used risk assessment model,
the Periodontal Risk Assessment tool or PRA, was
developed by Lang and Tonetti in 2003.
13
It uses six
factors/indicators (percentage of sites that exhibit
bleeding on probing, number of pocket depths >5
mm, number of teeth lost, radiographic bone loss to
age ratio, systemic and/or genetic conditions, and
smoking) to determine the level of risk for progression
of periodontitis.
The PRA differs from the PAT in that
the PRA was studied in patients who are undergoing
supportive (maintenance) periodontal treatment
while the PRC was developed for use prior to
initiating periodontal therapy. PRA risk scores have
been shown to correlate with the future tooth loss
in a retrospective study of periodontitis patients.
14
Other risk assessment models modified the PRA by
altering the input factors/indicators,
15
including the
inclusion of diabetes as a separate independent risk.
The PRA uses a graphic representation of disease
probability to inform both the practitioner and the
patient about the personal risk factors. The PRA
can be accessed online at www.perio-tools.com
(University of Berne, Switzerland).
A simplified modification of the PRA, termed the
UniFE risk assessment tool, was developed by
Trombelli and colleagues in 2009.
16
The UniFE
tool (see Table 3) uses only 5 factors/indicators