Jan Lindhe. Clinical Periodontology

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SUPPORTIVE PERIODONTAL THERAPY (SPT) • 7

Fig. 32-2. Histograms showing (a) average percentages of tooth surfaces harboring visible plaque (above) and in-

flamed gingival units (bleeding on probing) (below), and (b) average probing depth (above) and probing attach-

ment levels (below), at initial, baseline and follow-up examinations. (Data from Axelsson & Lindhe 1981b.)

recall group (Table 32-1). In the latter patients, 55% of

the sites showed a 2-5 mm further loss of attachment

at the 6-year examination, and 20% of the pockets were

4 mm deep or more (Tables 32-1 & 32-2).

Summary

Patients susceptible to periodontal disease are at high

risk for reinfection and progression of periodontal

lesions without meticulously organized and per-

formed

SPT. Since all patients who were treated for

periodontal

diseases belong to this risk category by

virtue of their

past history, an adequate maintenance

care program is

of utmost importance for a beneficial

long-term

treatment outcome. SPT has to be aimed at the regular

removal of the subingival microbiota and

must be

supplemented by the patient's efforts for

optimal

supragingival plaque control.

Table 32-1. Percentage of sites showing various

changes in probing attachment level between base-line

examination, 2 months after completion of ac

tive

periodontal therapy and follow-up examination

6 years

later. (Adapted from Axelsson & Lindhe

1981h)

Change in attachment level

Percentage of surfaces

showing change

Recall

Non-recall

Attachment level improved

No change

Attachment level worse by

72 10

1 mm

10 34

2to5mm

Table 32-2. Percentage of various probing depths in recall and non-recall patients at the initial examination, 2

months after active periodontal treatment and at 3 and 6-year follow-up visits. (Adapted from Axelsson &

Lindhe 1981b)

Examinations

Percentage of pockets of various depths

3 mm

4-6mm

7 mm

Recall

Non-recall

Recall

Non-recall

Recall

Non-recall

Initial

35 50

58 38

Baseline

1 0 0

3 years

9 0 0

6 years

99 80 19

786 • CHAPTER 32

SPT

FOR PATIENTS WITH

GINGIVITIS

Several studies – predominantly in children – have

documented that periodic professional prophylactic

visits in conjunction with reinforcement of personal

oral hygiene are effective in controlling gingivitis

(

Badersten et al. 1975, Poulsen et al. 1976, Axelsson &

Lindhe 1981a,b, Bellini et al. 1981). This, however,

does not imply that maintenance visits in childhood

preclude the development of more severe disease later

in life. It is obvious that SPT, therefore, must be a

lifelong commitment of both the patient and the pro-

fession.

Adults whose effective oral hygiene was combined

with periodic professional prophylaxes clearly were

healthier periodontally than patients who did not

participate in such programs (Lovdal et al. 1961,

Suomi et al. 1971). One particular study of historic

significance was performed on 1428 adults from an

industrial company in Oslo, Norway (Lovdal et al.

1961). Over a 5-year observation period, the subjects

were recalled 2-4 times per year for instruction in oral

hygiene and supragingival and subgingival scaling.

Gingival conditions improved by approximately 60%

and tooth loss was reduced by about 50% of what

would be expected without these efforts.

In another study (Suomi et al. 1971) loss of peri-

odontal tissue support in young individuals with gin-

givitis or only loss of small amounts of attachment

was followed over 3 years. An experimental group

receiving scaling and instruction in oral hygiene every

3 months yielded significantly less plaque and gingi-

val inflammation than the control group in which no

special efforts had been made. The mean loss of prob

ing attachment was only 0.08 mm per surface in the

experimental as opposed to 0.3 mm in the control

group.

When adult patients with gingivitis were treated

with scaling and root planing, but did not improve

their oral hygiene procedures, the gingival condition

did not improve compared with individuals receiving

prophylaxes at 6-month intervals (Listgarten &

Schifter 1982).

Summary

The available information indicates that the preven-

tion of gingival inflammation and early loss of attach

ment in patients with gingivitis depends primarily on

the level of personal plaque control, but also on further

measures to reduce the accumulation of supragingival

and subgingival plaque.

SPT

FOR PATIENTS WITH

PERIODONTITIS

As mentioned previously, a series of longitudinal

studies on periodontal therapeutic modalities was

performed in the past 25 years, first at the University

of Michigan, later at the University of Gothenburg,

Sweden, and also at the Universities of Minnesota,

Nebraska and Loma Linda. These studies always in-

corporated the patients into a well-organized mainte-

nance care system with recall visits at regular intervals

(generally 3-4 months). Although the patients per-

formed plaque control with various degrees of effi-

cacy, the SPT resulted in excellent maintenance of

postoperative attachment levels in most patients

(

Knowles 1973, Ramfjord et al. 1982).

On average, excellent treatment results with main

tained reduced probing depths and maintained gains

of probing attachment were documented for most of

the patients in the longitudinal studies irrespective of

the treatment modality chosen (Ramfjord et al. 1975,

Lindhe & Nyman 1975, Rosling et al. 1976, Nyman et

al. 1977, Knowles et al. 1979, 1980, Badersten et al.

1981, 1987, Hill et al. 1981, Lindhe et al. 1982a,

Pihlstrom et al. 1983b, Westfelt et al. 1983a,b, 1985,

Isidor & Karring 1986).

In a study on 75 patients with extremely advanced

periodontitis, who had been successfully treated for

the disease, a result of cause-related therapy and

modified Widman flap procedures (Lindhe & Nyman

1984), recurrent infection occurred in only very few

sites during a 14-year period of effective SPT. How-

ever, it has to be realized that recurrent periodontitis

was noticed at completely unpredictable time inter-

vals, but was concentrated in about 25% of the patient

population (15 out of 61). This suggests that, in a

periodontitis-susceptible risk population, the major-

ity of patients can be "cured" provided an optimally

organized SPT is performed, while a relatively small

proportion of patients (20-25%) will suffer from occa-

sional episodes of recurrent periodontal reinfection. It

is obviously a challenge for the diagnostician to iden-

tify such patients with very high disease susceptibility

and to monitor the dentitions for recurrent periodon-

titis on a long-term basis.

As opposed to the study by Lindhe & Nyman (1984)

which involved exclusively patients with advanced

periodontitis, another study on 52 patients with gen-

eralized mild to moderate adult periodontitis ad-

dressed the efficacy of SPT 8 years following comple-

tion of cause-related periodontal therapy (Bragger et

al. 1992). Full mouth intraoral radiographs were used

to assess changes in the radiographic alveolar bone

height as a percentage of the total tooth length. As a

result of cause-related therapy, a gain in probing at-

tachment followed by a loss of 0.5-0.8 mm over the

following 8 years was observed. The radiographic loss

of alveolar bone height in the same time period was

less than 2% and thus clinically insignificant.

this

SUPPORTIVE PERIODONTAL THERAPY (SPT) • 787

patient group initially presenting with mild to mod-

erate periodontitis, the frequency of SPT rendered per

year did not affect the rate of progression of periodon-

tal desease. However, patients seeking SPT less than

once per year over 8 years lost further periodontal

attachment during the period of observation. From

these studies it is evident that patients having experi-

enced periodontitis need some kind of SPT. Obviously,

the frequency of SPT visits has to be adapted to the

risk of susceptibility for the disease. Patients with

advanced periodontitis may need SPT at a regular and

rather short time interval (3-4 months), while for mild

to moderate forms of periodontitis, one annual visit

may be enough to prevent further loss of attachment.

Sumniary

SPT is an absolute prerequisite to guarantee beneficial

treatment outcomes with maintained levels of clinical

attachment over long periods of time. While the main-

tenance of treatment results for the majority of pa-

tients has been documented up to 14 years, it has to be

realized that a small proportion of patients will expe-

rience recurrent infections with progression of peri-

odontal lesions in a few sites in a completely unpre-

dictable mode. The continuous risk assessment at sub

ject, tooth and tooth site levels, therefore, represents a

challenge for the SPT concept.

CONTINUOUS MULTILEVEL RISK

ASSESSMENT

As opposed to an initial periodontal diagnosis which

considers the sequelae of the disease process, i.e. docu

ments the net loss of periodontal attachment and the

concomitant formation of periodontal pockets and the

existence of inflammation, clinical diagnosis during

SPT has to be based on the variations of the health

status obtained following successful active periodon-

tal treatment. This, in turn, means that a new baseline

will have to be established once the treatment goals of

active periodontal therapy (i.e. phases 1-3) are reached

and periodontal health is restored (Claffey 1991). This

baseline includes the level of clinical attachment

achieved while the inflammatory parameters are sup-

posed to be under control. Under optimal circum-

stances, supportive periodontal care would maintain

clinical attachment levels obtained after active ther-

apy for the years to come. The relevant question

would, therefore, be which clinical parameters may

serve as early indicators for a new onset or recurrence

of the periodontal disease process, i.e. reinfection and

progression of periodontal breakdown of a previously

treated periodontal site.

From a clinical point of view the stability of peri-

odontal conditions reflects a dynamic equilibrium be-

tween bacterial aggression and effective host re-

sponse. As such, this homeostasis is prone to sudden

changes whenever one of the two factors prevails.

Hence, it is evident that the diagnostic process must

be based on a continuous monitoring of the multilevel

risk profile. The intervals between diagnostic assess-

ments must also be chosen based on the overall risk

profile and the expected benefit. To schedule patients

for supportive periodontal therapy on the basis of an

individual risk evaluation for recurrence of disease

has been demonstrated to be cost-effective (Axelsson

& Lindhe 1981a,b, Axelsson et al. 1991).

By virtue of their previous disease predisposition,

all patients under a periodontal maintenance program

represent a population with a moderate to high risk

for recurrent periodontal infection. As opposed to the

general population without such a history, periodon-

tal patients need to participate in a well-organized

recall system which should provide both continuous

risk assessment and adequate supportive care. With-

out this, the patients are likely to experience progres-

sive loss of periodontal attachment (Axelsson &

Lindhe 1981a, Kerr 1981, Becker et al. 1984, Cortellini

et al. 1994, 1996). On the other hand, it is important to

determine the level of risk for progression in each

individual patient in order to be able to determine the

frequency and extent of professional support neces-

sary to maintain the attachment levels obtained fol-

lowing active therapy. The determination of such risk

level would thus prevent undertreatment, and also

excessive overtreatment, during SPT (Bragger et al.

1992).

Subject risk assessment

The patient's risk assessment for recurrence of perio-

dontitis maybe evaluated on the basis of a number of

clinical conditions whereby no single parameter dis-

plays a more paramount role. The entire spectrum of

risk factors and risk indicators ought to be evaluated

simultaneously. For this purpose, a functional dia-

gram has been constructed (Fig. 32-3) (Lang & Tonetti

2003) including the following aspects:

Percentage of bleeding on probing

Prevalence of residual pockets greater than 4 mm

Loss of teeth from a total of 28 teeth

Loss of periodontal support in relation to the pa-

tient's age

Systemic and genetic conditions

Environmental factors such as cigarette smoking.

Each parameter has its own scale for minor, moderate

and high risk profiles. A comprehensive evaluation,

the functional diagram will provide an individualized

total risk profile and determine the frequency and

complexity of SPT visits. Modifications maybe made

the functional diagram if additional factors become

important from future evidence.

Compliance

with recall

system

Several investigations have indicated that only a mi-

788 • CHAPTER 32

Syst./Gen.

PD>_5mm

Tooth

loss

Envir.

Fig. 32-3a. Functional diagram to

evaluate the patient's risk for recur-

rence of periodontitis. Each vector

represents one risk factor or indicator

with an area of relatively low risk, an

area of moderate risk and an area of

high risk for disease progression. All

factors have to be evaluated together

and hence the area of relatively low

risk is found within the center circle

of the polygon, while the area of

high

risk is found outside the periph

ery

of the second ring in bold. Be

tween

the two rings in bold, there is

the area

of moderate risk.

Fig. 32-3b. Functional diagram of a

low risk maintenance patient. BOP is

15%, four residual pockets ? 5 mm

are diagnosed, two teeth have been

lost, the bone factor in relation to the

age is 0.25, no systemic factor is

known and the patient is a non-

smoker.

PD>_5mm

Tooth

loss

nority of periodontal patients comply with the pre-

scribed supportive periodontal care (Wilson et al.

1984,

Mendoza et al. 1991, Checchi et al. 1994, De

metriou

et al. 1995). Since it has been clearly establ

ished that

treated periodontal patients who comply

with regular

periodontal maintenance appointments

have a better

prognosis than patients who do not

comply (Axelsson

& Lindhe 1981a, Kent 1981, Becker

et al. 1984,

Cortellini et al. 1994, 1996), non-compliant

or poorly

compliant patients should be considered at

higher risk

for periodontal disease progression. A re-port that

investigated the personality differences of patients

participating in a regular recall program as

compared

to patients who did not, revealed that pa

tients who did

not take part in a maintenance program

following periodontal therapy had higher incidences

stressful life events and less stable personal relation

ships in their lives (Becker et al. 1988).

Oral hygiene

Since bacterial plaque is by far the most important

etiologic agent for the occurrence of periodontal dis-

eases (for review see Kornman & Loe 1993), it is evi-

dent that the full mouth assessment of the bacterial

load must have a pivotal impact in the determination

of the risk for disease recurrence. It has to be realized,

however, that regular interference with the microbial

ecosystem during periodontal maintenance will even-

tually obscure such obvious associations. In patients

treated with various surgical and non-surgical mo-

SUPPORTIVE PERIODONTAL THERAPY (SPT) •

789

Fig. 32-3c. Functional diagram of a

medium risk maintenance patient.

BOP is 9%, 6 residual pockets ? 5

mm are diagnosed, four teeth have

been lost, the bone factor in relation

to the age is 0.75, the patient is a

Type I diabetic, but a non-smoker.

Syst./Gen.

PD?5mm

Tooth

loss

Envir.

Fig. 32-3d. Functional diagram of a

high risk maintenance patient. BOP

is 32%, ten residual pockets 5 mm

are diagnosed, ten teeth had been

lost, the bone factor in relation to the

age is 1.25, no systemic factor is

known and the patient is a occa-

sional smoker.

Syst./Gen.

PD?5mm

Tooth

loss

Envir.

dalities, it has been clearly established that plaque-in-

fected dentitions will yield recurrence of periodontal

disease in multiple locations, while dentitions under

plaque control and regular supportive care maintain

periodontal stability for many years (Rosling et al.

1976, Axelsson & Lindhe 1981a,b). Studies have thus

far not identified a level of plaque infection compatible

with maintenance of periodontal health. How-

ever, in a

clinical set-up, a plaque control record of 20-40%

might be tolerable by most patients. It is im

portant to

realize that the full mouth plaque score has

to be

related to the host response of the patient, i.e.

compared to inflammatory parameters.

Percentage of sites with bleeding on probing

Bleeding

on gentle probing represents an objective inflammatory

parameter which has been incorpo

rated into index

systems for the evaluation of periodontal conditions (

Loe & Silness 1963, Miihlemann

& Son 1971) and is

also used as a parameter by itself.

In a patient's risk

assessment for recurrence of periodontitis, BOP

reflects, at least in part, the patient's

compliance and

standards of oral hygiene perform

ance. Although

there is no established acceptable level

of prevalence of

bleeding on probing in the dentition

above which a

higher risk for disease recurrence has been established,

a BOP prevalence of 25% has been the cut-off point

between patients with maintained periodontal stability

for 4 years and patients with

recurrent disease in the same time frame in a prospec-

tive study in a private practice (Joss et al. 1994) (Fig.

32-4). Further evidence of BOP percentages between

20% and 30% determining a higher risk for disease

progression originates from studies of Claffey et al.

(

1990) and Badersten et al. (1990).

In assessing the patient's risk for disease progres-

sion, BOP percentages reflect a summary of the pa-

tient's ability to perform proper plaque control, the

patient's host response to the bacterial challenge and

the patient's compliance. The percentage of BOP,

therefore, is used as the first risk factor in the func-

tional diagram of risk assessment (Fig. 32-3). The scale

runs in a quadratic mode with 4, 9, 16, 25, 36 and >

49% being the divisions on the vector.

Individuals with low mean BOP percentages (<

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 reinfection.

Prevalence of

residual pockets greater than 4 mm

The enumeration of the residual pockets with probing

depths greater than 4 mm represents — to a certain

extent — the degree of success of periodontal treatment

rendered. Although this figure

per se

does not make

much sense when considered as a sole parameter, the

evaluation in conjunction with other parameters such

as bleeding on probing and/or suppuration will re

flect

existing ecologic niches from and in which rein

fection

might occur. It is, therefore, conceivable that

periodontal stability in a dentition would be reflected

a minimal number of residual pockets. Presence of

high frequencies of deep residual pockets and deep-

ening of pockets during supportive periodontal care

has, in fact, been associated with high risk for disease

progression (Badersten et al. 1990, Claffey et al. 1990).

On the other hand, it has to be realized that an in-

creased number of residual pockets does not necessar-

ily imply an increased risk for re-infection or disease

progression, since a number of longitudinal studies

have established the fact that, depending on the indi-

vidual supportive therapy provided, even deeper

pockets may be stable without further disease pro-

gression for years (e.g. Knowles et al. 1979, Lindhe &

Nyman 1984).

Nevertheless, in assessing the patient's risk for dis-

ease 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 (Fig. 32-3). The scale runs

790 • CHAPTER

Fig. 32-4. Distribution of "looser" sites (probing depth PD ? 4 mm) due to periodontal disease progression with or

without concomitant recession, dependent on the mean bleeding on probing percentage (BOP) during an observa-

tion period of 4 years. Patients are sorted by decreasing mean BOP percentages. Patients with < 20% BOP have a

significantly lower risk for disease recurrence. (Data from Joss et al. 1994.)

SUPPORTIVE PERIODONTAL THERAPY (SPT) • 791

in a linear mode with 2, 4, 6, 8, 10 and 12% being the

divisions on the vector.

Individuals with up to four residual pockets may

be regarded as patients with a relatively low risk,

while patients with more than eight residual pockets

may be regarded as individuals with high risk for

recurrent disease.

Loss of teeth from a total of

teeth

Although the reason for tooth loss may not be known,

the number of remaining teeth in a dentition reflects

the functionality of the dentition. Mandibular stability

and individual optimal function may be assured even

with a shortened dental arch of premolar to premolar

occlusion, i.e. 20 teeth. The shortened dental arch does

not seem to predispose the individual to mandibular

dysfunction (Witter et al. 1990, 1994). However, if

more than eight teeth from a total of 28 teeth are lost,

oral function is usually impaired (Kayser 1981, 1994,

1996). Since tooth loss also represents a true end-point

outcome variable reflecting the patient's history of

oral

diseases and trauma, it is logical to incorporate

this

risk indicator as the third parameter in the func-

tional diagram of risk assessment (Fig. 32-3). 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 divisions on the vector.

Individuals with up to four teeth lost may be re-

garded as patients in low risk, while patients with

more than eight teeth lost may be considered as being

in high risk.

Loss of periodontal support in relation to the

patient's age

The extent and prevalence of periodontal attachment

loss (i.e. previous disease experience and susceptibil-

ity), as evaluated by the height of the alveolar bone on

radiographs, may represent the most obvious indica-

tor of subject risk when related to the patient's age. In

light of the present understanding of periodontal dis-

ease progression, and the evidence that both onset and

rate of progression of periodontitis might vary among

individuals and during different time frames (van der

Velden 1991), it has to be realized that previous attach

ment loss in relation to the patient's age does not rule

out the possibility of rapidly progressing lesions.

Therefore, the actual risk for further disease progres-

sion in a given individual may occasionally be under-

estimated. Hopefully, the rate of progression of dis-

ease has been positively affected by the treatment

rendered and, hence, previous attachment loss in re-

lation to patient's age may be a more accurate indica-

tor during SPT than before active periodontal treat-

ment. Given the hypothesis that a dentition may be

functional for the most likely life expectancy of the

subject in the presence of a reduced height of peri-

odontal support (i.e. 25-50% of the root length), the

risk assessment in treated periodontal patients may

represent a reliable prognostic indicator for the stabil-

ity of the overall treatment goal of keeping a func-

tional dentition for a lifetime (Papapanou et al. 1988).

The estimation of the loss of alveolar bone is per-

formed in the posterior region on either periapical

radiographs, in which the worst site affected is esti-

mated gross as a percentage of the root length, or on

bite-wing radiographs in which the worst site affected

is estimated in mm. One mm is equated with 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 posterior

site affected would be scored BL/Age = 0.5. Another

40-year-old patient with 50% bone loss at the worst

posterior site scores BL/Age = 1.25.

In assessing the patient's risk for disease progres-

sion, the extent of alveolar bone loss in relation to the

patient's age is estimated as the fourth risk indicator

for recurrent disease in the functional diagram of risk

assessment (Fig. 32-3). The scale runs in increments of

0.25 of the factor BL/Age, with 0.5 being the division

between low and moderate risk and 1.0 being the

division between moderate and high risk for disease

progression. This, in turn, means that a patient who

has lost a higher percentage of posterior alveolar bone

than his/her own age is at high risk regarding this

vector in a multifactorial assessment of risk.

Systemic conditions

The most substantiated evidence for modification of

disease susceptibility and/or progression of peri-

odontal disease arises from studies on Type I and Type

II (insulin-dependent and non-insulin-dependent)

diabetes mellitus populations (Gusberti et al. 1983,

Emrich et al. 1991, Genco & Loe 1993).

It has to be realized that the impact of diabetes on

periodontal diseases has been documented in patients

with untreated periodontal disease, while, as of today,

no clear evidence is available for treated patients. It is

reasonable, however, to assume that the influence of

the systemic conditions may also affect recurrence of

disease.

In recent years, genetic markers have become avail

able to determine various genotypes of patients re-

garding their susceptibility for periodontal diseases.

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). Also, there is a trend to higher

tooth loss in the IL-1 genotype positive subjects

(

McGuire & Nunn 1999). In a retrospective analysis of

over 300 well-maintained periodontal patients, the

IL-1 genotype positive patients showed significantly

higher BOP percentages and a higher proportion of

patients which yielded higher BOP percentages dur-

ing a 1-year recall period than the IL-1 genotype nega

tive control patients (Lang et al. 2000). Also, the latter

group had twice as many patients with improved BOP

percentages during the same maintenance period, in

dicating that IL-1 genotype positive subjects do in-

792 • CHAPTER 32

deed represent a group of hyper-reactive subjects even

if they are regularly maintained by effective SPT (Lang

et al. 2000). In a prospective study over 5 years on

Australian white collar and blue collar workers on a

University campus, the IL-1 genotype positive age

group above 50 years showed significantly deeper

probing depth than their IL-1 genotype negative coun

terparts, especially when they were non-smokers.

In assessing the patient's risk for disease progres-

sion, systemic factors are only considered, if known,

as the fifth risk indicator for recurrent disease in the

functional diagram of risk assessment (Fig. 32-3). In

this case, the area of high risk is marked for this vector.

If not known or absent, systemic factors are not taken

into account for the overall evaluation of risk.

Research on the association and/or modifying in-

fluence in susceptibility and progression of periodon-

titis of physical or psychologic stress is sparse (Cohen

Cole et al. 1981, Green et al. 1986, Freeman & Goss

1993). The hormonal changes associated with this con

dition, however, are well documented (Selye 1950).

Cigarette smoking

Consumption of

tobacco,

predominantly in the form of

smoking or chewing, affects the susceptibility and the

treatment outcome of patients with adult periodonti-

tis. Classical explanations for these observations have

included the association between smoking habits and

poor oral hygiene as well as unawareness of general

health issues (Pindborg 1949, Rivera-Hidalgo 1986).

More recent evidence, however, has established that

smoking

per se

represents not only a risk marker, but

probably a true risk factor for periodontitis (Ismail et

al. 1983, Bergstrom 1989, Bergstrom et al. 1991, Haber

et al. 1993). In a young population (19-30 years of age),

51-56% of periodontitis was associated with cigarette

smoking (Haber et al. 1993). The association of smok-

ing and period ontitis has been shown to be dose-de-

pendent (Haber et al. 1993). It has also been shown that

smoking will affect the treatment outcome after scal-

ing and root planing (Preber & Bergstrom 1985), modi

fied Widman flap surgery (Preber & Bergstrom 1990),

and regenerative periodontal therapy (Tonetti et al.

1995). Furthermore, a high proportion of so-called

refractory patients has been identified as consisting of

smokers (Bergstrom & BlomlOf 1992). The impact of

cigarette smoking on the long-term effects of peri-

odontal therapy in a population undergoing suppor-

tive periodontal care has been reported. Smokers dis-

played less favorable healing responses both at re-

evaluation and during a 6-year period of supportive

periodontal care (Baumert-Ah et al. 1994). In spite of

the paucity of evidence relating cigarette smoking to

impaired outcomes during supportive periodontal

care, it seems reasonable to incorporate heavy smok-

ers (> 20 cigarettes/day) in a higher risk group during

maintenance.

In assessing the patient's risk for disease progres-

sion, environmental factors such as smoking must be

considered as the sixth risk factor for recurrent disease

in the functional diagram of risk assessment (Fig.

32-

3). While non-smokers (NS) and former smokers

(FS)

(more than 5 years since cessation) have a rela

tively

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 (

OS; < 10 cigarettes a day) and moderate smok

ers (

MS) may be considered in moderate risk for dis

ease

progression.

Calculating the patient's individual periodontal risk

assessment (PRA)

Based on the six parameters specified above, a multi-

functional diagram is constructed for the PRA. In this

diagram, the vectors have been constructed on the

basis of the scientific evidence available. It is obvious

that ongoing validation may result in slight modifica-

tions.

A low PR patient has all parameters within the low

risk categories or at the most one parameter in the

moderate risk category (Fig. 32-3b).

A moderate PR patient has at least two parameters in

the moderate category, but at most one parameter

in the high risk category (Fig. 32-3c).

A high PR patient has at least two parameters in the

high risk category (Fig. 32-3d).

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 resid

ual

periodontal pockets, tooth loss, an estimation of

the

loss of periodontal support in relation to the pa

tient's

age, an evaluation of the systemic conditions of

the

patient, and finally, an evaluation of environ-

mental

and behavioral factors such as smoking and stress.

All these factors should be contemplated and

evaluated together. A functional diagram (Fig. 32-3)

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.

Tooth risk assessment

Tooth position

within the dental arch

Early clinical surveys have associated the prevalence

and severity of periodontal diseases with malocclu-

sion and irregularities of tooth position (Ditto & Hall

1954, Bilimoria 1963). However, many subsequent

studies using clinical evaluation methods could not

confirm these conclusions (Beagrie & James 1962, Gei

ger 1962, Gould & Picton 1966). Although a relation-

ship between crowding and increased plaque reten-

tion and gingival inflammation has been established

(

Ingervall et al. 1977, Buckley 1980, Griffith & Addy

1981, Horup et al. 1987), no significant correlation

SUPPORTIVE PERIODONTAL THERAPY (SPT) •

793

between anterior overjet and overbite (Geiger et al.

1973), crowding and spacing (Geiger et al. 1974) or

axial inclinations and tooth drifts (Geiger & Wasser-

man 1980) and periodontal destruction, i.e. attach-

ment loss subsequent to gingival inflammation, could

be established. It is evident from the literature men-

tioned that crowding of teeth might eventually affect

the amount of plaque mass formed in dentitions with

irregular oral hygiene practices, thus contributing to

the development of chronic gingivitis, but, as of today,

it remains to be demonstrated whether tooth malpo-

sition within the dental arch will lead to an increased

risk for periodontal attachment loss.

Furcation

involvement

It is evident that multirooted teeth with periodontal

lesions extending into the furcation area have been the

subject of intensive therapeutic studies for many years

(Kalkwarf & Reinhardt 1988). Retrospective analyses

of large patient populations in private periodontal

practices of periodontal specialists (Hirschfeld & Was

serman 1978, McFall 1982) have clearly established

that multirooted teeth appear to be at high risk for

tooth loss during the maintenance phase. The most

impressive long-term documentation maintained 600

patients for an average duration of 22 years, and 10%

of these patients were even maintained for more than

30 years (Hirschfeld & Wasserman 1978). While 83%

of the patients could be considered "well maintained"

and had lost only 0-3 teeth during the observation

period, a patient group of 4% (25) was identified with

an extreme risk for disease progression and had lost

between 10 and 23 teeth during a regularly scheduled

maintenance program. Irrespective of the patient

group of low, moderate, and high risk for disease

progression during maintenance, the majority of the

teeth lost were furcation-involved molars (Hirschfeld

& Wasserman 1978). Similar results were obtained in

a study on 100 treated periodontal patients main-

tained for 15 years or longer (McFall 1982).

Prospective studies on periodontal therapy in mul-

tirooted teeth have also revealed significant differ-

ences between non-molar sites and molar flat surfaces

on the one hand and molar furcation sites on the other,

when looking at the treatment outcomes evaluated as

bleeding frequency, probing depth reductions and lev

els of attachment (Nordland et al. 1987). Again, teeth

with furcation involvement and original probing

depths > 6 mm had reduced treatment outcomes.

The assumption that the prognosis for single rooted

teeth and non-furcation-involved multirooted teeth is

better than the prognosis for furcation-involved mul-

tirooted teeth has also been confirmed by Ramfjord et

al. (1987) in a prospective study over 5 years. It has to

be realized, however, that these results are not in-

tended to imply that furcation-involved teeth should

be extracted, since all the prospective studies have

documented a rather good overall prognosis for such

teeth if regular supportive care is provided by a well-

organized maintenance program.

Iatrogenic factors

Overhanging restorations and ill-fitting crown mar-

gins certainly represent an area for plaque retention,

and there is an abundance of association studies docu

menting increased prevalence of periodontal lesions

the presence of iatrogenic factors (for review see

Leon

1977). Depending on the supragingival or sub-

gingival location of such factors, their influence on the

risk for disease progression has to be considered. It has

been established that slightly subgingivally located

overhanging restorations will, indeed, change the

ecologic niche, providing more favorable conditions

for the establishment of a Gram-negative anaerobic

microbiota (Lang et al. 1983). There is no doubt that

shifts in the subgingival microflora towards a more

periodontopathic microbiota, if unaffected by treat-

ment, represent an increased risk for periodontal

breakdown.

Residual periodontal support

Although many clinicians believe that teeth with re-

duced periodontal support are unable to function

alone and should be extracted or splinted, there is

clear evidence from longitudinal studies that teeth

with severely reduced, but healthy, periodontal sup-

port can function either individually or as abutments

for many years without any further loss of attachment

(Nyman & Lindhe 1979, Nyman & Ericsson 1982,

Bragger et al. 1990). Hence, successfully periodontally

treated teeth can be maintained over decades and

function as abutments in fixed bridgework or as indi-

vidual chewing units irrespective of the amount of

residual periodontal support, provided that physi-

ologic masticatory forces do not subject such teeth to

progressive trauma which may lead to spontaneous

extraction. Obviously, by virtue of the already reduced

support, should disease progression occur in severely

compromised teeth, this may lead to spontaneous

tooth exfoliation.

Mobility

In light of the discussion of abutment teeth with se-

verely reduced but healthy periodontal support, tooth

mobility may be an indicator for progressive trau-

matic lesions, provided that the mobility is increasing

continuously (Nyman & Lang 1994). When assessing

tooth mobility, it has to be realized that two factors

may contribute to hypermobility: (1) a widening of the

periodontal ligament as a result of unidirectional or

multidirectional forces to the crown, high and fre-

quent enough to induce resorption of the alveolar

bone walls; and (2) the height of the periodontal sup-

porting tissues. If this is reduced due to prior peri-

odontal disease, but the width of the periodontal liga-

ment is unchanged, the amplitude of root mobility

within the remaining periodontium is the same as in

a tooth with normal height, but the leverage on the

tooth following application of forces to the crown is

changed. Therefore, it has to be realized that all teeth

that have lost periodontal support have increased

794 •

CHAPTER

tooth mobility as defined by crown displacement upon

application of a given force. Nevertheless, this

hypermobility should be regarded as physiologic

(

Nyman & Lindhe 1976).

Since tooth mobility is probably more frequently

affected by reduced periodontal height rather than

unidirectional or multidirectional application of

forces

onto the tooth, its significance for the evaluation

of the

periodontal conditions has to be questioned. Several

studies have indicated that tooth mobility

varies

greatly before, during and after periodontal

therapy (

Persson 1980, 1981a,b). From these studies it

can be

concluded that periodontally involved teeth

show a

decrease in mobility following non-surgical

and/or

surgical periodontal procedures. However,

following

surgical procedures, tooth mobility may

temporarily

increase during the healing phase and

may resume

decreased values later on. Provisional

splinting as an

adjunct to non-surgical or surgical

therapy does not

seem to affect the final result of tooth

mobility.

Summary

The tooth risk assessment encompasses an estimation

of the residual periodontal support, an evaluation of

tooth positioning, furcation involvements, presence of

iatrogenic factors and a determination of tooth mobil-

ity to evaluate functional stability. A risk assessment

on the tooth level may be useful in evaluating the

prognosis and function of an individual tooth and

may indicate the need for specific therapeutic meas-

ures during SPT visits.

Site risk assessment

Bleeding on probing

Absence of bleeding on probing is a reliable parameter

to indicate periodontal stability if the test procedure

for assessing bleeding on probing has been stand-

ardized (Lang et al. 1990). Presence of bleeding upon

standardized probing will indicate presence of gingi-

val inflammation. Whether or not repeated bleeding

on probing over time will predict the progression of a

lesion is, however, questionable (Lang et al. 1986,1990,

Vanooteghem et al. 1987). Nevertheless, a 30% prob-

ability for attachment loss to occur in the future may

be predicted for sites repeatedly positive for bleeding

on probing (Fig. 32-5) (Badersten et al. 1985, 1990,

Lang et al. 1986, Vanooteghem et al. 1987,1990, Claffey

et al. 1990).

Obviously, bleeding on probing is rather sensitive

to different forces applied to the tissues. An almost

linear relationship (R = 0.87) existed between the prob

ing force applied and the percentage of bleeding sites

in a study on healthy young adults (Fig. 32-6) (Lang

al. 1991). If the probing force exceeded 0.25 N (25 g),

the tissues were traumatized and bleeding was pro-

voked as a result of trauma, rather than as a result of

tissue alterations due to inflammation. To assess the

Fig. 32-5. Positive predictive values for loss of probing

attachment of ? 2 mm in 2 years in sites which bled on

probing 0, 1, 2, 3 or 4 times out of four SPT visits in a to-

tal of 48 patients following active periodontal therapy.

(

Data from Lang et al. 1986.)

"true" percentage of bleeding sites due to inflamma-

tion, a probing force of 0.25 N or less should be ap-

plied, which clinically means a light probing force.

This has also been confirmed for patients who have

experienced loss of attachment, i.e. with successfully

treated advanced periodontitis (Fig. 32-7) (Karayian-

nis et al. 1991, Lang et al. 1991).

Since absence of bleeding on probing at 0.25 N

indicated periodontal stability with a negative predic-

tive value of 98-99% (Lang et al. 1990), this clinical

parameter is the most reliable for monitoring patients

over time in daily practice. Non-bleeding sites maybe

considered periodontally stable. On the other hand,

bleeding sites seem to have an increased risk for

progression of periodontitis, especially when the

same site is bleeding at repeated evaluations over

time

(Lang et al. 1986, Claffey et al. 1990).

It is, therefore, advisable to register the sites which

bleed on probing (BOP) in a dichotomous way using

constant force of 0.25 N. This allows the calculation of

the mean BOP for the patient, and yields also the

topographic location of the bleeding site. Repeated

scores during maintenance will yield the surfaces at

higher risk for loss of attachment.

Probing

depth and

loss of attachment

Clinical probing is the most commonly used parame-

ter both to document loss of attachment and to establ-

ish a diagnosis of periodontitis. There are, however,

some sources of error inherent in this method which

contribute to the variability in the measurements.

Among these are (1) the dimension of the periodontal

probe; (2) the placement of the probe and obtaining a

reference point; (3) the crudeness of the measurement

scale; (4) the probing force; and (5) the gingival tissue

conditions.