Periodontal risk and risk assessment is very importnant in monitoring periodontally affected patients, this seminar will give you an idea about periodontal risk factors and how to make a periodontal risk assessment for patients.

1. Periodontal Risk and
Making a Risk
Assessment
IBRAHIM BAYRAM
BDS, MFD RCSI, MFDS RCPSG
MCLINDENT STUDENT (PROS), CARDIFF UNIVERSITY

2. Introduction
Plaque-associated periodontal diseases are chronic infections caused by mixed microbial flora,
resulting in an inflammatory process that leads to periodontal attachment loss and ultimately
tooth loss.
The role of bacteria in the initiation of periodontal disease is primary, a range of host-related
factors influence the clinical presentation and rate of progression of disease.
This means that there may be considerable variation among individuals in their risk for disease
progression.

3. Introduction
Individual variability in periodontitis progression has been documented in longitudinal studies
both in untreated and treated populations.
Risk assessment by the clinician for an individual is performed by recognizing factors associated
with periodontal disease and making a subjective judgement as to the extent to which these
factors may contribute to disease progression.
In a longitudinal study of Sri Lankan tea plantation workers, with no access to dental care and
poor oral hygiene, a large variation in individual risk for disease progression was observed. While
81% of this population were found to have moderate progression and 11% no progression of
disease, a small percentage, 8%, were described as having rapid disease progression during a 15-
year follow-up period (Löe et al. 1986).

4. Introduction
Risk can be identified in terms of risk factors, risk indicators, or risk predictors.
For clinicians, accurate prediction of patients or sites at high risk is very important.
Diagnostic tests differentiate whether or not a person has a specific disease at the time.

5. Risk factor
Factors that significantly increase the likelihood that people without disease, if exposed to these
factors, will develop the disease within a specific time interval.
Should satisfy two criteria:
1) Biologically proven as a causal agent for disease.
2) Shown to precede the development of disease in prospective clinical studies.
A risk factor may be modified by intervention, thereby reducing the likelihood that the particular
disease will occur.
Smoking is an example of a risk factor for periodontal disease, since there are a number of
biologically explanations for it as a causative agent, and prospective clinical studies have shown that
smokers are more likely to develop periodontitis than nonsmokers.

6. Risk indicator vs. Risk predictor
Risk indicators are factors that have proven to be significantly associated with the occurrence
of a specific disease but only in cross-sectional studies.
 Risk predictor is a factor that has no current biological evidence as a causative agent but has
been associated with disease on a cross-sectional or longitudinal basis.
May be either markers or other historical measures of disease.
Examples are the number of missing teeth or past evidence of periodontal disease. The number of
missing teeth is a risk predictor for disease, but has little or no biological evidence as a causative agent
for periodontitis.

7. Classification of Risk Factors
True or Putative
Systemic or Local
Modifiable or non-modifiable

8. Classification of Risk Factors
True risk factor: have a causal association, that is, when present, they increase the likelihood of
the disease developing, but when they are removed the disease improves.
Example: biofilm around the teeth.
Putative risk factors: associated with the occurrence of a disease, as observed in cross-
sectional studies however there is a lack of evidence from longitudinal studies that removal of
the risk factors will improve the disease state.
Example: nutritional factors.

9. Classification of Risk Factors
Systemic risk factors: affect the host response either directly or indirectly, they may be
environmental (stress), lifestyle (nutrition, smoking) or those relating to general health (DM,
immunodeficiency, leucocyte adhesion defects, etc..).
Local risk factors: essentially biofilm retention factors, which may be anatomical in nature (root
grooves, enamel pearls) or iatrogenic (poor restoration margins, dental appliances close to
gingival margins, etc..).

10. Classification of Risk Factors
Modifiable risk factors: can be influenced by the patient or the clinician, may be systemic
(improved diabetes control, improved diet) or environmental in nature (smoking cessation,
improved oral hygiene, correction of restoration margin, etc..).
Non-modifiable risk factors: can not be influenced by the patient and essentially relate to
genetic traits or characteristics.

11. Risk Factors
Smoking
Smoking has both topical and systemic effects which place patients at greater risk of
periodontal progression.
Smokers were found to have:
More pockets, deeper pockets, more recession, more bone loss, increased tooth loss and less
marginal bleeding that can have the effect of masking early critical signs of periodontitis.
The healing response to non-surgical and surgical periodontal therapy is poorer in smokers and
maintenance patients who smoke are twice as likely to lose teeth as non-smokers.
A dose response exists between smoking and periodontal risk.

12. Risk Factors
Pathogenic Bacteria and Microbial Tooth Deposits
Studies demonstrate a causal relationship between the accumulation of bacterial plaque and
gingival inflammation. However, a causal relationship between plaque accumulation and
periodontitis has been more difficult to establish.
Although quantity may not indicate risk, there is evidence that the composition, or quality, of the
complex plaque biofilm is important.
In terms of quality of plaque, three specific bacteria have been identified as etiologic agents for
periodontitis: Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Tannerella
forsythia.
Diabetes
Epidemiologic data demonstrate that the prevalence and severity of periodontitis are significantly
higher in patients with type 1 or type 2 diabetes mellitus than in those without diabetes and that the
level of diabetic control is an important variable in this relationship.

13. Risk Factors
Anatomic factors, such as furcations, root concavities, developmental grooves, cervical enamel
projections, enamel pearls, and bifurcation ridges, may predispose the periodontium to disease
as a result of their potential to harbor bacterial plaque and present a challenge to the clinician
during instrumentation.
The presence of subgingival and overhanging margins in restorations can result in increased
plaque accumulation, increased inflammation, and increased bone loss.
 Although not clearly defined as risk factors for periodontitis, anatomic factors and restorative
factors that influence plaque accumulation may play a role in disease susceptibility for specific
teeth.

14. Risk Determinants/Background
Characteristics
Genetic factors
Kornman and colleagues demonstrated that alterations (polymorphisms) in specific genes encoding inflammatory
cytokines such as (IL-1α) and (IL-1β) were associated with severe chronic periodontitis in nonsmoking subjects.
Aggressive periodontitis.
Genetic Disorders Associated With Periodontitis (Chédiak–Higashi syndrome, Ehlers–Danlos syndrome and Papillon–
Lefèvre syndrome).
Stress
Emotional stress may interfere with normal immune function and may result in increased levels of circulating
hormones, which can affect the periodontium.
Apparent association exists between psychosocial factors and risk behaviors such as smoking, poor oral hygiene.
Low socioeconomic level
Gingivitis and poor oral hygiene can be related to lower socioeconomic status (SES), this most likely can be attributed
to decreased dental awareness and decreased frequency of dental visits compared with more educated individuals with
higher SES.

15. Risk Determinants/Background
Characteristics
Age
Both prevalence and severity of periodontitis increase with age probably due to the cumulative effect of
prolonged exposure to true risk factors.
As people age, their immune system starts to weaken “Immunosenescence” reducing their ability to kill
pathogens and increasing the collateral tissue damage caused.
Therefore an age‐related, rather than an age-dependent, increased susceptibility to periodontitis in older
people is therefore biologically plausible.
Sex
No established, inherent difference between men and women in their susceptibility to periodontal disease.
Although men have been shown to exhibit worse periodontal conditions than women in multiple studies from
different populations, this difference has been traditionally considered to reflect the documented better oral
hygiene practices and/or increased utilization of oral health care services among women.
On the other hand, there is evidence for sexual dimorphism in elements of both the innate and the acquired
immunity that may lead to enhanced pro‐inflammatory responses in men. (Shiau & Reynolds 2010)

16. Risk Indicators
Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome
Osteopenia/osteoporosis
Reduced bone mass seen in osteoporosis may aggravate periodontal disease progression.
Irregular dental care/visits
Non or poorly compliant patients should be considered to be at higher risk for periodontal
disease progression.

17. Risk Markers/Predictors
Previous history of periodontal disease
Patients with the most severe existing loss of attachment are at the greatest risk for future loss
of attachment. Conversely, patients currently free of periodontitis have a decreased risk for
developing loss of attachment compared with those who currently have periodontitis.
Bleeding on Probing
Bleeding on probing is the best clinical indicator of gingival inflammation.
Although this indicator alone does not serve as a predictor for loss of attachment, bleeding on
probing coupled with increasing pocket depth may serve as an excellent predictor for future
loss of attachment.
Lack of bleeding on probing does appear to serve as an excellent indicator of periodontal
health.

18. Clinical Risk Assessment for Periodontal
Disease
Information concerning individual risk for developing periodontal disease is obtained through
careful evaluation of the patient’s demographic data, medical history, dental history, and clinical
examination.
Once the social, demographic, medical history, dental history, and clinical presentation data are
collected, they must be analyzed to identify whether the patient is at risk for developing
periodontal disease.
This analysis can be accomplished by the health care provider or through the use of a
computer-based risk assessment tool.
Once an at-risk patient is identified and a diagnosis is made, the treatment plan may be
modified accordingly.

19. Risk Assessment in Periodontal Therapy

20. Multifactorial Risk Assessment Models
Periodontal risk calculator (PRC)
◦ Developed a computer-based risk assessment tool for objective, quantitative assessment of risk.
◦ The calculation of risk using this model is based on mathematically derived algorithms that assign relative
weights to nine factors including patient age, smoking history, diagnosis of diabetes, history of periodontal
surgery, pocket depth, furcation involvements, restorations or calculus below the gingival margin, radiographic
bone height and vertical bone lesions.
◦ The PRC assigns the individual a level of risk on a scale from 1 (lowest risk) to 5 (highest risk).
(page et al. 2003)
Periodontal risk assessment (PRA) (hexagonal risk diagram) (Lang & Tonetti 2003)
PRA/multifactorial risk diagram (Renvert & Perrson 2004)
◦ Modification of the PRA model

21. Periodontal Risk Assessment (PRA) (Hexagonal
Risk Diagram) (Lang & Tonetti 2003)
The patient's risk assessment for recurrence of periodontitis may be evaluated on the basis of a number of
clinical conditions whereby no single parameter displays a more paramount role.
The entire spectrum of risk factors and risk indicators ought to be evaluated simultaneously.
For this purpose, a functional diagram has been constructed including the following aspects:
 1. Percentage of bleeding on probing
 2. Prevalence of residual pockets greater than 4 mm
 3. Loss of teeth from a total of 28 teeth
 4. Loss of periodontal support in relation to the patient's age
 5. Systemic and genetic conditions
 6. Environmental factors, such as cigarette smoking
Each parameter has its own scale for minor, moderate and high-risk profiles.
A comprehensive evaluation of the functional diagram will provide an individualized total risk profile and
determine the frequency and complexity of SPT visits.
Modifications may be made to the functional diagram if additional factors become important in the future.

22. Functional diagram

23. Percentage of sites with bleeding on
probing (BOP)
BOP percentages reflect a summary of the patient's ability to perform proper plaque control,
the patient's host response to the bacterial challenge and the patient's compliance, especially
when only few residual pockets remain after active periodontal therapy.
The percentage of BOP is used as the first risk factor in the functional diagram of risk
assessment.
The scale runs in a quadratic mode with 4, 9, 16, 25, 36 and > 49% being the critical values on
the vector.
Individuals with low mean BOP percentages of < 10% of the surfaces may be regarded as
patients with a low risk for recurrent disease (Lang et al, 1990), while patients with mean BOP
percentages > 25% should be considered to be at high risk for periodontal breakdown.

24. Prevalence of residual pockets ≥5 mm
(residual pocket greater than 4 mm)
Periodontal stability in a dentition would be reflected in a minimal number of residual pockets.
Presence of high frequencies of deep residual pockets and deepening of pockets during
supportive periodontal care has been associated with high risk for disease progression.
In assessing the patient's risk for disease progression, the number of residual pockets with a
probing depth of ≥5 mm is assessed as the second risk indicator for recurrent disease in the
functional diagram of risk assessment.
 The scale runs in a linear mode with 2, 4, 6, 8, 10 and ≥12% being the critical values on the
vector.
Individuals with up to 4 residual pockets may be regarded as patients with a relatively low risk,
while patients with more than 8 residual pockets as individuals with high risk for recurrent
disease.

25. Loss of teeth from a total of 28 teeth
The number of teeth lost from the dentition without the third molars (28 teeth) is counted,
irrespective of their replacement.
The scale runs also in a linear mode with 2, 4, 6, 8, 10 and 12 being the critical values on the vector.
The third risk indicator for recurrent disease in the functional diagram of risk assessment.
Individuals with up to 4 teeth lost may be regarded as patients in a low risk category, while patients
with more than 8 teeth lost may be considered as being in a high risk category.
Rationale for this stems from the significance of further tooth loss in terms of preservation of the
function of the dentition.

26. Loss of periodontal support in relation to
the patient's age
The extent and prevalence of periodontal attachment loss, as evaluated by the height of the alveolar
bone on radiographs, may represent the most obvious indicator of subject risk when related to the
patient’s age.
The estimation of the loss of alveolar bone is performed in the posterior region on either periapical
radiographs, in which the worst site affected is grossly estimated in per cent of the root length or on
bitewing radiographs in which the worst site affected is estimated in millimeter.
On bitewing radiographs, one millimeter is considered to be equal to 10% bone loss.
The percentage is then divided by the patient's age, this results in a factor.
As an example, a 40-year-old patient with 20% of bone loss at the worst affected posterior site
would score BL/Age = 0.5.
The fourth risk indicator for recurrent disease in the functional diagram of risk assessment.
The scale runs in increments of 0.25 of the factor BL/Age, with 0.5 being the critical value to
discriminate between low and moderate risk and 1.0 being the division value for moderate and high
risk.

27. Systemic and genetic aspects
The most substantiated evidence for modification of disease susceptibility and/or progression of
periodontal disease arises from studies on Type I and Type II diabetes mellitus populations. (Gusberti et al,
1983; Emrich et al, 1991; Genco and Löe, 1993)
Research on the Interleukin-1 (IL-1) polymorphisms has indicated that IL-1 genotype positive
patients show more advanced periodontitis lesions than IL-1 genotype negative patients of the same
age group. (Kornman et al, 1997) and there is a trend to higher tooth loss in the IL-1 genotype positive
subjects. (McGuire and Nunn, 1999)
The IL-1 genotype positive patients showed significantly higher BOP percentages and a higher
proportion of patients which yielded higher BOP % during a one-year recall period than the IL-1
genotype negative control patients. (Lang et al, 2000)
Systemic factors, if known, are only considered as the fifth risk indicator for recurrent disease in the
functional diagram of risk assessment.
If not known or absent, systemic factors are not taken into account for the overall evaluation of
risk.

28. Cigarette smoking
Environmental factors such as smoking must be considered as the sixth risk factor for recurrent
disease in the functional diagram of risk assessment.
While non-smokers (NS) and former smokers (FS; more than 5 years since cessation) have a
relatively low risk for recurrence of periodontitis, the heavy smokers (HS; as defined by smoking
more than one pack per day) are definitely at high risk.
Occasional smokers (OS; < 10 cigarettes a day) and moderate smokers (MS; 10-19 cigarettes a
day) may be considered at moderate risk for disease progression.

29. Calculating The Patient's Individual
Periodontal Risk Assessment (PRA)
A low PRA patient has all parameters within the low-risk categories or - at the most - one
parameter in the moderate-risk category.
A moderate PRA patient has at least two parameters in the moderate category, but at most
one parameter in the high-risk category.
A high PRA patient has at least two parameters in the high-risk category.

30. Examples

31. Examples

32. Examples

33. High-risk patient
In a high-risk patient who yields high BOP percentages and high numbers of residual pockets,
the patient's risk for disease progression may be reduced into the moderate category if further
periodontal therapy is provided.
These two parameters are easily affected by therapy, while other parameters, such as numbers
of missing teeth or systemic and genetic factors are either irreversible and cannot be reduced or
may only be affected with great additional efforts (smoking cessation).

34. In summary
The subject risk assessment may estimate the risk for susceptibility for progression of
periodontal disease.
It consists of an assessment of the level of infection (full mouth bleeding scores), the
prevalence of residual periodontal pockets, tooth loss, an estimation of the loss of periodontal
support in relation to the patient's age, an evaluation of the systemic conditions of the patient
and finally, an evaluation of environmental and behavioral factors such as smoking. All these
factors should be contemplated and evaluated together.
A functional diagram may help the clinician in determining the risk for disease progression on
the subject level.
This may be useful in customizing the frequency and content of SPT visits.

35. Thanks for listening
Ibrahim Bayram