Cost-effectiveness of varioustreatment modalities for adultchronic periodontitis

PER E. GJERMO & JOSTEIN GRYTTEN

The aim of this review was to assess the cost-effec-

tiveness of various modalities for chronic periodon-

titis in adults. We searched the literature for studies

where time consumption and monetary costs (where

available) were used as expressions of the resources

required to perform the following types of services:

providing information on the disease and oral

hygiene instruction for patients; removal of subgin-

gival calculus; access surgery; and maintenance and

prevention of recurrence of the disease. The following

outcome variables were chosen: retention of teeth, or

a surrogate variable such as change in bone level

measured on X-rays taken at the start and at the end

of a 1-year (or longer) period. The literature search

did not reveal any studies where these outcome

variables could be linked to information on resources

used in treatment. Therefore, we reviewed relevant

studies where different treatment techniques were

used but where the outcome variables were different.

This review revealed that in most cases it was difficult

to assess whether one type of treatment (or inter-

vention) is more effective than another. We conclude

that better data are needed, in particular on out-

comes, so that valid comparisons can be made be-

tween different types of treatment, for different types

of studies.

Periodontal disease is an inflammatory disease

induced by bacterial plaque adhering to the tooth

surface in contact with the gingiva. A lesion that is

contained in the gingival margin is termed gingivitis.

Gingivitis may be regarded as the result of an

immunologic reaction and as an attempt by the

organism to prevent the development of the tissue-

destructive component of periodontal disease called

periodontitis. Gingivitis will always precede perio-

dontitis, but its development into periodontitis

is rare (50). The development of gingivitis into

periodontitis is multifactorial and is believed to

occur in susceptible individuals where homeostasis

is not successfully established by the host. Perio-

dontitis is characterized by the loss of periodontal

fibers and alveolar bone, eventually leading to the

loss of teeth. The course of the disease and the rate

of progression are affected by genetic and environ-

mental factors. These comprise variation in the

amount of bacteria (oral hygiene) and their compo-

sition in plaque (63), some medical disorders

(human immunodeficiency virus, diabetes) and

drugs affecting the immune system (steroids, cal-

cium inhibitors) (34). In addition, life-style factors,

such as tooth-cleaning habits (58) and tobacco

consumption (9), seem to play an important role in

determining susceptibility to, and the rate of pro-

gression of, the disease. As a result of its chronic

character and the fact that the bacteria causing the

most common forms of periodontitis are micro-

organisms that are endogenous in the human oral

flora (and probably important for prevention of other

infections by exogenous bacteria), periodontitis has a

propensity for recurrence after treatment. In fact, the

only predictable method to eradicate periodontal

disease in a patient is to extract all teeth. However, in

spite of this as a treatment option, which would

probably be very cost-effective and one that has been

considered in special circumstances (17), it will not

be considered in this review.

Treatment of periodontitis has been directed to-

wards the changeable risk factors, first and fore-

most oral hygiene and, in the later years, smoking

habits. The professional removal of bacterial plaque

from the tooth surfaces is crucial in all forms of

periodontal treatment, and training patients in the

daily self-removal of plaque is an essential part

of prevention of disease recurrence following

269

Periodontology 2000, Vol. 51, 2009, 269275

Printed in Singapore. All rights reserved

2009 John Wiley & Sons A/S

PERIODONTOLOGY 2000

treatment (33). The effect of tobacco consumption

has become more and more evident over the last

few decades (9), particularly concerning the more

severe forms of periodontitis (22). Therefore,

counseling regarding smoking and other forms of

tobacco use has become very important in com-

bating this chronic disease. The treatment of

periodontitis thus includes changing life styles for

life, because the risk of recurrence will always fol-

low a susceptible host, thus making the treatment

approach particularly complex, involving many

psychological aspects (12, 56).

The successful treatment of periodontitis is be-

lieved to prevent further progression of the tissue-

destructive processes involved (13), not necessarily

to obtain an inflammation-free gingival margin.Regeneration of lost tissue may occur, but this is rare

and of little magnitude, and is therefore usually not a

general goal for treatment. There is, however, no

agreement on how to assess treatment success. No

further tooth loss, or retention of teeth during a

definite time span, would be parameters that are

tangible for patients (10, 26). As periodontitis devel-

ops very slowly, even without treatment (39, 40), this

is difficult to assess in clinical trials. However, a few

studies have been conducted with fairly long obser-

vation periods and adequate outcome variables,

unfortunately without cost-effectiveness aspects in-

cluded within their design (3, 20, 51). A concept

named quality-adjusted tooth-years (QATYs) has

been suggested (1), but this needs further develop-

ment and testing before it can be recommended.

Consequently, surrogate variables are used. The most

common surrogate variables are strongly related to

the degree of inflammation of the periodontal tissues,

such as bleeding on probing, probing pocket depth

and clinical attachment level. Unfortunately, the

degree of inflammation is only vaguely predictive of

future loss of supporting tissues and teeth (36, 57).

Probably, a stable bone level, as assessed on radio-

graphs, is the most valid assessment of no progres-

sion (27), but because of the slow development of the

disease in question, even studies with bone loss as

the outcome variable might require several years to

provide valid information about the effect of various

treatment approaches.

The systematic treatment of periodontitis thus

includes thorough information about the disease,

the causes and contributing factors (smoking, etc.),

and the impact of personal oral hygiene in addition

to the professional removal of supragingival and

subgingival plaque, calculus and overhangs on res-

torations and crowns (retention factors) (debride-

ment). In order to obtain access to subgingival root

surfaces, surgery may be necessary (33, 66). This

may comprise gingivectomy (removal of the gingiva

covering the root surfaces) or flap procedures where

the flaps are replaced and sutured after scaling and

root planing. Treatment with antibiotics, either

locally or systemically, is recommended in some

cases (30, 43, 45, 48, 61, 64). In addition, other

antimicrobial agents have been suggested (15, 18,

24, 31).

For mechanical debridement of the root surfaces a

number of techniques and instruments have been

developed, as well as suggestions on whether to treat

the entire oral cavity in one setting (to avoid con-

tamination from untreated sites) (52), or to divide the

mouth into either sextants or quadrants that are

treated sequentially with weeks interval between

each session. Also, the sequence of treatments have

been subject to discussions about, for instance,

whether it is necessary to obtain a certain level of oral

hygiene before treatment planning, or whether pre-

scaling before surgery should be recommended (6).

However, few studies including the economic as-

pects of the various approaches have been con-

ducted, and in those that have been carried out, the

validity is often limited to one country and its social

and economic situation, the peoples needs andrequirements, and the national system for delivering

and paying for health services; therefore, these

studies have limited general validity. Some studies

have estimated the time needed for performing var-

ious periodontal treatment procedures as an expres-

sion of resources needed. In the present review we

will regard both time consumption and monetary

costs as expression of resources required to perform

treatment modalities.

Johansen et al. (28) presented the Periodontal

Treatment Need System (PTNS) which is based on

the three basic procedures: motivation and instruc-

tion in effective oral hygiene measures; subgingival

debridement of the root surfaces of periodontally

involved teeth; and debridement facilitated by

surgery. The resources needed for each of these

therapeutic measures were calculated as time con-

sumption (7), and hypothetically applied to several

populations (8, 29). In a later study, Mubarak &

Gjermo (46) showed that the results were also

applicable to patients actually treated and with

acceptable accuracy. However, the Periodontal

Treatment Need System does not consider mainte-

nance, which is regarded as an important and inte-

gral part of periodontal treatment and crucial for

long-term success (37, 38).

270

Gjermo & Grytten

Methods

In order to approach the problem of cost-effective-

ness of treatment modalities, we decided to use, as

outcome variable, either tooth loss or retention, or as

surrogate variables, bone level measured on radio-

graphs (27) in randomized clinical trials. Variables

indicating mostly variations in the degree of inflam-

mation (bleeding on probing, probing pocket depth,

clinical attachment level) were not accepted. Thus,

we applied level 5, according to Lundgren et al. (42),

as our end point, which is a rather coarse measure

but which is tangible to people. In order to assess,

with a certain degree of confidence, that the treat-

ment had resulted in arrest of the progression of the

disease, we required an observation time of at least

1 year.

The terms cost-effectiveness, costbenefit andcostutility have recently been discussed by Bragger(10) and we chose to use his definitions. This implies

that cost-effectiveness studies could include studies

where more than one treatment modality reached the

same end-point and the costs were compared, or

where different results were obtained at the same

cost using different treatment modalities. Possible

benefits (firm teeth, chewing capacity, avoiding

prosthetic replacements) and adverse effects of a

treatment type (sensitivity, antibiotic resistance,

negative cosmetics) were disregarded.

A literature search was performed using the terms

periodontal therapy and cost-effectiveness, cost,time consumption, time factor and time, andperiodontal treatment modalities and cost-effec-tiveness, cost, time consumption, time factor andtime, in Medline (PubMed) and the CochraneLibrary. In addition, a hand search was performed in

relevant journals after 2003 with special attention

given to reference lists in review articles on related

subjects.

Results

No randomized clinical trials were found that sat-

isfied the requirements for an outcome variable that

was tangible for patients (tooth loss, tooth retention,

radiographic assessments of bone level) and of

sufficient duration to disclose further progression of

the disease after treatment (1 year). Thus, a sys-

tematic review was not possible. However, some

studies that tried to address the cost-effectiveness

aspects of periodontal treatment modalities were

identified and our further comments are based on a

narrative review of those studies and on previous

reviews of related subjects.

Results and discussion of thenarrative review (four treatmentmodalities are considered)

Information about the disease andpractical training of patients inpracticing home-based optimal oralhygiene

At a population level, regular check-ups, which

include professional plaque removal, demonstrate

positive effects upon periodontal health parameters

(47), but whether this is a cost-effective strategy to

apply to entire populations is questionable because

efforts would be spent on individuals not at risk of

periodontitis. Very few studies have been published

on providing information to, and training of, adult

periodontal patients, particularly where cost assess-

ments have been taken into consideration.

Bellini (6) performed time studies on the motiva-

tion and instruction required to reach a defined level

of plaque control in adult patients. He concluded that

he needed an average of 72 min to reach an accept-

able level of oral hygiene, and that this was not

associated with baseline oral hygiene or number of

teeth. Because of to the use of advertisements in the

mass media and the increased awareness of the need

for plaque control in the general public in western

countries (22), one would predict that lower re-

sources are now required. There are indications from

studies in adolescents that the application of extra

resources in the form of repeated group teaching

and or with parent participation programs, inaddition to individual training in oral hygiene per-

formance, displayed marginal gains only, compared

with more simplified programs (11, 25, 44). This is in

accordance with recent studies employing motiva-

tional interviewing to obtain patient compliance

(12, 56).

Some improvement in plaque control, as a result of

the use of electrical counter-rotational toothbrushes,

has been shown in controlled trials (32, 53, 54). In this

context one should mention that the cost of an

electric toothbrush has not been evaluated in relation

to the marginal gains reported over manual brushes

in reducing plaque levels. Moreover, there are indi-

cations in the literature that quit smoking programsmay be cost-effective (16).

271

Cost-effectiveness of treatments for adult chronic periodontitis

Subgingival debridement

Subgingival debridement is the cornerstone of all

periodontal treatment (33), and many studies con-

firm its effectiveness in controlling mild to moderate

periodontitis (pockets 5 mm) (41, 62), (24, 20, 35,51). For this purpose, various techniques and

instruments, both manual and machine driven, have

been developed and their effect compared (14, 19, 60,

65). The majority of studies show only marginal dif-

ferences in outcome and time consumption for per-

forming the various procedures (59, 67). One recent

review indicates that ultrasonic instrumentation of

single-rooted teeth may yield a time gain as com-

pared with manual debridement (65). However, be-

cause the equipment necessary for ultrasonic, laser

or other machine-driven instruments infers extra

costs, scaling and root planing with manual scalers

may be regarded as the most cost-effective treatment

modality for mild and moderate disease. In severe

cases of periodontitis, adjunctive antibacterial treat-

ment (systemically or locally applied) seems to

provide a small additional benefit (23, 45, 48, 64).

However, while the adjunctive use of systemically

applied antibiotics may be relatively cheap, the costs

for single tooth treatment with local drug-delivery

systems are not negligible (10). Full-mouth debride-

ment (52), used in combination with systemic anti-

biotics, has shown a small, but clinically insignificant,

advantage over the conventional approach (37, 38).

For severe periodontitis (periodontal pockets

6 mm), closed nonsurgical treatment may beinsufficient to arrest the disease, although this is

generally recommended as the first treatment ap-

proach. The result of the nonsurgical approach must

then be evaluated and surgery performed if satisfac-

tory results are not obtained (33). From a cost-

effectiveness perspective this approach will add

to the costs when surgery is necessary, compared to

the costs if surgery had been performed immediately

(6, 7).

Access surgery

In the treatment of chronic periodontitis, periodontal

surgery is performed to obtain access to affected root

surfaces for the removal of calculus and biofilm (68).

This may be obtained by gingivectomy or various flap

procedures. The type of procedure chosen does not

influence the outcome when this is assessed as no

further progression of the disease, provided that

optimal plaque control is maintained by the patient

(55). However, lack of plaque control after perio-

dontal surgery always results in failure (49), regard-

less of the surgical technique employed. This would

tend to favor gingivectomy as a result of the sim-

plicity of the method that probably renders it

the more cost-effective option. However, other as-

pects, such as unwanted side effects (sensitivity,

cosmetics), may be influenced by the technique used

and should be evaluated when the choice is made.

There are indications that prescaling before surgery

may require more time than debridement after sur-

gery (7). This would make it cost-effective to perform

surgery without prescaling if it is obvious that surgery

will be needed. It has been suggested that performing

scaling during or after surgery requires less time than

a systematic subgingival debridement (6, 7). The

difficulty is that there are no absolute criteria to

determine when surgery would be indicated.

Adjunctive systemic antibiotics have been shown

to offer some advantage to the treatment outcome in

severe periodontitis cases and in refractory perio-

dontitis (45, 64), but a recent report questions the

usefulness in combination with surgical approaches

(23). However, the increased cost of a single course of

antibiotics does not influence the total cost of treat-

ment in a way that would be decisive for the cost-

effectiveness of the treatment.

Maintenance and prevention ofrecurrence

There is widespread agreement in the literature that

patients treated for periodontitis require life-long

maintenance, with needs-related supportive care,

which includes reinforcement of oral hygiene

practices, scaling and prophylaxis (20, 37, 38). It is

disputed how often these maintenance sessions are

required, but there are indications that several times

per year is no better than once a year and the value of

routine professional removal of plaque has been

questioned when patients home care is adequate (5).Also, there are indications that the outcome of sup-

portive periodontal care is better when taken care of

by specialists, compared with general practitioners,

but at a higher cost (21). Noncompliance with a

maintenance program, however, predictably results

in the recurrence of the disease (49). Local applica-

tion of antibiotics in affected pockets during

maintenance care has been suggested (61), but at a

higher cost (10) and with an increased risk of

developing antibiotic resistance. It seems conceivable

that cost-effectiveness gains may be obtained in

maintenance programs, but thus far data are scarce

and inconclusive.

272

Gjermo & Grytten

Concluding remarks

As inflammation is variably associated with destruc-

tive disease and difficult for patients to assess, future

studies on the cost-effectiveness of periodontal

treatment modalities would benefit from focusing on

end point variables, such as tooth loss or tooth

retention, that are tangible for our patients. Because

of the slow progression of chronic periodontitis, even

in populations that do not receive treatment (39, 40),

the study period should preferably extend to several

years. The study period may be reduced if bone loss,

assessed on radiographs, is employed as a surrogate

outcome variable (27). Cost-effectiveness studies in

many other fields in medicine have the advantage of

having well-defined and distinct end points. For

example, with respect to the treatment of cancer, the

chosen end point is usually the 5-year survival rate. It

is easier to compare the costs of different types of

treatment when the expected outcome is well defined

and agreed upon, compared to when it is not.

Therefore, one challenge for periodontics is to de-

velop outcome criteria that can be generally accepted

and to which costs can be related.

The narrative review of articles that were not ac-

cepted for our systematic review indicates that the

main cost gains in periodontal therapy would be

achieved by avoiding unnecessary surgery and by

applying intervals of 1 year or more in the life-long

maintenance phase. Variation in other modalities

would probably display only minor differences in

cost.

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