Comnnmity Dent Oral Epidemiol 1995: 23: 159-64Printed in Denniart< . .411 rii^llt.',' reserved

Copyright © Muttksgaard 1995

Commumfy Dentistryand Oral Epidemiology

ISSN 0301-5661

Costs of periodontal andprosthodontie treatment andevaluation ot oral health in patientsafter treatment of advancedperiodontal diseaseKarlsson G, Teiwik A, Lundstrom A, Ravald N: Costs of periodontal andprosthodontie treatment and evaluation of oral health in patients after treatment ofadvanced periodontal disease. Community Dent Oral Epidemiol 1995; 23: 159-64.© Munksgaard, 1995

Abstract - Retrospective estimations of dental care costs of periodontal and pros-thodontie treatment and evaluation of oral health in 37 patients with advancedperiodontal disease were carried out. Measures of their subjective evaluation of oralhealth 7-10 yr after the treatment are presented as a health profile and as indices insingle numbers. The relations between oral health as an index and the dimensionsin the health profile are analyzed. Dental care costs for treatment in the mandiblewas SEK 35 550, for the tnaxilla SFK 45 380 and for both jaws SEK 74 230. Afterthe treatment oral health as well as general health were in excess of 75 on a 0 to100 scale. Chewing ability, comfort and aesthetics were the variables found to sig-nificantly affect the subjective oral health. Oral health in terms of periodontaland prosthodontie conditions was maintained over the observation period.

Goran Karlsson\ Anders Teiwik^,Asa Lundstrom^ and Nils Ravald^^Center for Medical Technology Assessment,Linkoping, University. ^Department ofPeriodontology, Public Dental Service, Linkoping,Sweden

Key words: dental care: economic evaluation:periodontal treatment

Goran Karlsson, Center for Medical TechnologyAssessment, Linkoping University, S-581 83Linkoping, Sweden

Accepted for publication 17 May 1994

In treating partially edentulous patientsdifferent alternatives are offered, such asremovable dentures, fixed bridges or den-tal implants. The effects as well as theresources needed differ between the al-ternatives but also within the alterna-tives. Due to subsidies of dental treat-ments in Sweden there will be a diver-gence between private and public costs.To assist decision-making in issues con-cerning allocation of resources, formaleconomic evaluations are helpful. In eco-nomic evaluations the costs for a treat-ment are related to the benefits. The so-cioeconomic problem is to identify pa-tients (indications) for whotn a therapyproduces benefits in excess of costs.

The therapy causes direct and indirectcosts and produces effects (benefits). The

direct costs are the value of the resourcesused in treating the patient. Indirectcosts are resources foregone due to thetreatment of the disease.

The main benefit of dental treatmentis probably a better functioning andquality of life. The measurement of thisbenefit can be performed in differentways. For an overview see JONSSON &KARLSSON (1).

Traditionally, odontologic parametersare used to describe the outcome oftreatment. Another approach is to pre-sent the patient's subjective experience ofdifferent ditnensions of health, such aschewing ability, comfort and aesthetics.Consequently both methods of analysesare of interest.

The aim of this study was to calculate

the dental care costs in patients treatedfor periodontal disease and rehabilitatedwith fixed bridges, and to evaluate thepatients" oral health.

Material and methods

The subjects included in this study werechosen from all patients referred to theDepartment of Periodontology, PublicDental Service, Linkoping, Sweden, in1977. All patients who at a 3-yr follow-up exatnination had a fixed bridge in oneor both jaws as a result of the periodon-tal treattnent were selected. Eor inclusionin the study the bridge had to includeone side and the front, and extend atleast to the canine on the opposite side.Forty-five patients fulfilled these criteria.

160 KARLSSON ET AL.

7 yH,ii cx

I nilnw up

Fig. 1. Time schedule of the treatment and ob-servation period.

Due to deaths, changes in place of livingor lack of data frotn the referral dentists,the number of patients included in thisstudy was reduced to 37, of whom 22were female and 15 male. The mean agewas 52±s.d. 10, range 31-73, at the startof the treatment. The length of educa-tion was short for 23, medium for 10,extended (academic) for two and un-known for two of the patients.

The sequence and the time schedule ofthe treatment are shown in Fig. I. Allpatients were given periodontal treat-ment at the Department of Periodontlo-gy. The prosthodontie treatment wasprovided by the referring dentist, exceptfor seven patients, three of whom re-ceived their prosthodontie treatment atthe Department of Periodontology andfour at the Department of Prosthodon-tics. All other measures, such as treat-ment of caries lesions and maintenance,have been performed by the referringdentists.

Dental status - Odontologic data werecollected for patients attending the 7-yrexamination using the periodontal re-cords at the Department of Periodontol-ogy and the case sheets from referring

dentists. The reported population thusconsists of 22 patients with a bridge inthe maxilla, six patients with a bridge inthe mandible and five patients withbridges in both jaws. Four patients failedfrom the examination 7 yr after treat-ment.

Periodontal status was measured asdescribed by LINDHI- & NYMAN (2).Probing depths exceeding 3 mm proxi-mally and 2 mm buccally and linguallywere recorded. All measurements werescored to the nearest millimeter. Plaqueindices (PI%) were recorded as percent ofsurfaces with plaque detected either bystreaking the tooth surface with a perio-dontal probe or as visible occurrence ofplaque. Recordings were made from ap-proximal, buccal and lingual surfaces.Gingival indices (GI%) were recorded aspercent of pockets with bleeding afterprobing pocket depth.

Heatth tneasure estirttations - The ba-sis for the measures of health and con-struction of a health profile was a ques-tionnaire which was sent to all 37 pa-tients. The questionnaire consisted of 44items related to problems with oral orgeneral health, to which the patientcould answer yes or no. These items wereclustered to nine health dimensions, ex-pressed as a health profile. For each di-mension the score was 0 if all items wereanswered with yes. If all itetns were an-

Chcwin^ability

swered with no, the score was 100. A highscore accordingly means a good state ofhealth. The dimensions are shown in Fig.2. The dimensions of general health arethe corresponding ditnensions of part I ofthe Nottingham Health Profile (3) but theweights were evaluated on a Swedishpopulation (4). All items within each di-mension describing the oral health areshown in Table 1. Within each dimensionall items were given the same weights. Inthe Nottingham Health Profile a highscore means poor health. However, whenhealth is described as a single index (uti-lity value) a high value means goodhealth. To avoid confusion, high scores inthis study mean good health.

Utility values have been estimated byusing the rating scale technique (5). Inmeasuring the oral health index (OHel)and the general health index (GHel) thepatients were asked to value their healthstate on a scale, where 0 stands for deepdissatisfaction and 100 for complete sat-isfaction.

Also included in the questionnairewere questions as whether or not the pa-tient was satisfied with the treatment andthe result of the treatment, whether ornot the patient would be willing toundergo the same treattnent again ifneeded, and whether or not the patientcould imagine an alternative treatment.

The relation between OHel and the di-

oRAL

IIEALTH

Comfort

Aesthetics

Flioiictics

Embarrass-ment

Fig. 2. Health profile.Subjeetively pereeivedoral and general healthin 36 patients. A highseore means goodhealth.

GENERAL

HEALTH

Energy

Emotionalreactions

Sociali.<:olation

Sleep

WiVt'i'i'i't ill Wm'iV

i^ri iyii i npii^ii^ 1̂l i II II n i l

mm II Jiumuu <• m -i.

25 50

Score

100

Econottiic evahtation of detital treattnent 161

Table 1. Dimensions and items for measurement of oral health

Dimensions/itetns Weicht

Chewittg abilityDo you have to be carelul what you are eating due to your teeth?Do you have trouble biting with your teeth?Do you have trouble chewing what you would like to, due to your bridge?Do you have trouble eating hard foods such as, for example, carrots?Do you have trouble eating meat due to your teeth?Do you have to be eareful what you are eating due to your bridge?

CotnfortHave you any pain whieh you relate to your bridge?Does your bridge move unpleasantly when you are ehewing?Does it feel unpleasant or difficult to keep your bridge clean?Do you get food under your bridge when you are eating certain things?Does it hurt when you aie eating?Do you experience your bridge as a foreign objeet in your mouth?Do you experienee your bridge as unpleasantly movable?Are you afraid that your bridge may come loose any time?

AestheticsWould you be prepared to suffer an extetisive treatment just to get your bridge neaterthan today'.'Is there anything concerning the appearance ol'your bridge whieh you are not satisfiedwith?Do you think that your appearance has changed for the worse due to your bridge?

Etnbarra.s.stnentDo you think that other people notice that you are wcaritig a bridge?Does it happen that you try to hide the bridge by, for example, putting your hand orsomething in front of your mouth?Are your relatives aware that you are wearing a bridge?When you meet other people, do you notice how their teeth look?Does the bridge make you avoid laughing when you meet other people?

100/6100/6100/6100/6100/6100/6

100.00

100/8100/8100/8100/8100/8100/8100/8100/8

100.00

100/3

100/3100/3

100.00

100/5

100/5100/5100/5100/5

100.00

ring dental team were calculated in ac-cordance with the fees of this system.The laboratory costs for the bridges werecalculated from the dental technicianbills for 18 patients. For 19 patients,where bills were unavailable, estimateswere based on the reimbursement systemfees.

The costs for specialist care were cal-culated as the average cost per dentalhour at these departtnents multiplied bythe time used for the treatment. Thesecosts include capital cost, costs for assist-ing personnel and materials. Thus, thesecosts were the actual calculated costs forthe treatment and not the cost accordingto the fees.

All costs are expressed as 1989 Swed-ish kronor and are discounted to thedate of referral with a discount rate of4"/,.

Statistical tnethod - The statisticalmethod used was the multiple regressiontechnique. The functional fortn was lin-ear multiplicative (log-log) for the healthmeasuretnents. In the selection of the in-dependent variables the starting pointhas been a general model, where allavailable variables were included, where-after the statistically significant variableshave been eliminated by a sequentialtesting procedure using F-test at the 5%level.

mensions in the health profile was statis-tically analyzed. Correspondingly, thequestion whether oral health correlatedto psychological and social reactions ornot and to what extent oral health af-fected general health were analyzed.

Cost estitnations - The cost estima-tions were retrospectively calculatedfrom case sheets from all treating clinics,including dentist, hygienist and techni-cian tneasures including prostheticmaterials. The registration of resources,limited to the jaw needing prosthodontie

Table 2. Prosthodontie status at bridge inser-tion

Mean SD

MaxiiiaNo. of bridge unitsNo. of abutments

MandibieNo. of bridge unitsNo. of abutments

127

105

±2±2

±1±1

rehabilitation, has been performed fromthe date of referral up to and includingthe 7-yr examination (Fig. 1).

All referring dental teams and techni-cians were associated with the Swedishreimbursement system, where fees arepaid in accordance with fixed prices oftreatment measures or, to a minor ex-tent, in accordance with treatment timeused. The costs with regard to the refer-

ResultsDetttal statits - The extension of thebridges is sutnmarized in Table 2. Thetime span between insertion and the 7-yrexamination was 6.6±0.9 yr. All but onebridge had the original extension at thefinal examination. Due to root fractureof one abutment and following lost re-tention and extensive caries of another,one bridge in the maxilla was reduced on

Table 3. Number of teeth, plaque scores and periodontal conditions at baseline and the 7-yrexamination

Baseline 7-yr examination

Mean Pl%Mean Gr/o

MaxillaNo. of teeth% surfaees with ppd >5 mm

MandibleNo. of teeth"Al surfaees with ppd s 5 mm

49±18

28733

11235

11±2913 ±20

1834

634

lnsuffieient registrations.

162 KARLSSON HT AI,..

one side and supplemented with a partialprosthesis. Additionally in another pa-tient one abutment tooth was lost due tocaries. Out of initially 238 abutments 235were still functioning at the 7-yr exami-nation. In one case a section of a bridgein the maxilla was remade due to lost re-tention. In another subject one abutmentin the mandible was changed to a singlecrown for the same reason.

Endodontic treatment of one abut-ment followed by a cast core was carriedout at various times alter cementation inseven patients with a bridge in the maxil-la and in one patient in the mandible.One patient needed this treatment fortwo teeth in the maxilla, thus a total ofnine abutments (4%) needed endodonticcare after the bridge was placed.

Periodontal data are summarized inTable 3. The number of teeth was heavilyreduced in connection with the perio-dontal and prosthodontie treatment butthe remaining teeth showed as a wholeimproved periodontal health during thetime of observation. Two non-abutmentteeth were lost due to further periodontalbreakdown during the observationperiod. Plaque and gingival indices werereduced after treatment and maintainedat a low level at the 7-yr examination.

Health measures - The questionnairewas answered by 36 out of the 37 pa-tients. The mean score of the oral healthindex (OHel) was 79, s.d. ±26, and of thegeneral health index (GHel) 64, s.d.±34.The health profile is presented in Fig. 2.

Thirty-four patients (92%) reportedsatisfaction with the treatment and theresult, one patient (3%) was doubtfuland two patients (6%) were not satisfied.On a multiple-choice question about thewillingness to undergo the same treat-ment once again if needed, 25 patients(67%) answered yes, eight patients (22%)

Table 4. Explanatory model of subjeetivelypereeived oral health (OHel). Log-linear func-tional Ibrm

Table 5. Explanatory model of emotional reactions and social isolation. Log-hnear form

Variable (3-values t-ratios

InterceptChewing abilityComfortAestheties

-5.220.511.460.17

-2.49**4 29****2.75***2.07**

R==0.769: Adj R-=0.747; DF=34

**** Significant at the 0.1% level.*** Significant at the 1% level.

** Significant at the 5% level.

Independentvariable

InterceptOHelEnergy

R=Adj R2DF

Emotional

P-values

3.930.040.11

0.431O..395

34

Dependent

reaction

t-ratios

28.27***1.53"-'-4.59****

variable

Social

P-values

3.520.130.11

0.4360.401

34

isolation

t-ratios

16.84****3.76****3.07***

**** Significant at the 0.1% level.*** Significant at the I'/o level,

n.s., not significant.

Table 6. Average dental care cost per patient. 1989 SEK. Diseount rate=4'V(i

Type of treatment

ExaminationsPeriodontal treatment

SurgicalNon-.surgical

Endodontie tteatmcntRestorative dentistryProsthodontie treatment''

Sum

Prosthetic tnaterial and technician time

Dental care costss.d

Mandible

kronor

6 530

3 3602 030

750860

11 610

25 140

10410

35 550(1 950)

%

19

10622

33

71

30

100

Maxill:

kronor

7 280

3 4802 1401 2101 430

16 480

32 020

13 480

45 380(11 390)

1

"A.

16

8533

37

70

30

100

Both jaws

kronor

7 720

6 4702 630I 960

73028 020

47 530

26 700

74 230(8 300)

%,

10

9431

38

64

36

100

'' Excluding materials and teehnician time.

hesitated and four patients (11%)) an-swered no. Nine patients (25%) couldimagine an alternative treatment. Ofthese, six patients preferred dental im-plants, two patients removable denturesand one patient hygienist treatmentalone.

The regression model of OHel as afunction of the oral health ditnensions inthe profile is shown in Table 4. Subjec-tively, oral health (OHel) was signifi-cantly affected by chewing ability, cotn-fort and aesthetics. The multiple regres-sion models in Table 5 show that in thisstudy oral health (OHel) significantly af-fected social isolation but not emotionalreactions. The first equation shows thatenergy, but not OHel, significantly af-fected emotional reactions. According tothe second equation, OHel as well as en-ergy positively affected social isolation.According to our data, oral health didnot significantly affect general health.

Costs - The dental care costs are pre-sented in Table 6. The dental care costsfor treatment in the mandible were35 550 SEK, in the maxilla 45 380 SEKand in both jaws 74 230 SEK. For all 37patients in this study the costs for pros-thodontie treatment, including costs formaterial and technician time, were 67%)of the dental care costs.

Discussion

The present study shows that it is pos-sible to treat and maintain advancedperiodontal disease over a 7-yr periodthrough periodontal and prosthodontietreatment. This is in agreetnent withother studies (6, 7). Also the occurrenceof failures is sitnilar to findings by LIND-HE & NYMAN (7). In this study, aftertreatment, periodontal breakdown was aminor problem compared to technicaland endodontic complications.

Ecottontic evalitatiott of dental treattnent 163

In an economic evaluation costs andbenefits of different therapies are com-pared. In this study it was not possiblefor ethical reasons to randomize patientsto different treatment modalities, sinceall preferred rehabilitation with a fixedprosthesis. Consequently, the presentstudy is not a full economic evaluationbecause alternative treatment is nottaken into account. Complete econotnicevaluations of dental therapies are so farrare (1). However, costs and benefits oftreatment with osseointegrated implantsad modum Brancmark are reported byKARLSSON (8). The implant patients hada different oral health status before treat-ment compared to the patients in thisstudy but showed a similar subjectivelyperceived oral health state after the treat-ment, calculated in a similar manner.The average dental care cost for an im-plant bridge was SEK 50 000 in the max-illa and 48 000 Ibr the mandible, in 1989prices. However, the follow-up perioddiffers between the studies.

There are several studies concerningthe cost and cost containment for theSwedish dental insurance (9-11) but toour knowledge no study takes the totaltreattnent cost into account nor analysesthe costs in relation to the patient's oralhealth in a longer time perspective. Mosteconomic evaluations of dental technol-ogies have mainly been performed forpreventive care such as fiuoridation andsealant programs (1). To our knowledgethere are no economic studies on treat-ment of patients with periodontaldisease. Recently, however, other dentaltreatments have been economically eval-uated (12, 13). These studies are basedon hypothetical treatments. Hypotheticaltreatments may not correctly take intoaccount the costs for complications andmight underestimate some other treat-tnent costs. For the decision-maker thecosts, the oral health and the patients"quality of life is of interest. Thus, the val-ue of the present study is that the actualcosts and the actual oral health of treat-ed patients are presented.

As in other retrospective studies thedata in this study are connected with un-certainty. Some of the dental care costswere not calculable from exact figuresbut are estimations based on case sheets.The estimates are, however, in our opin-ion over- rather than underestimations.

Our methods of measuring subjectiveoral health have to our knowledge not

been used before. The patients prefer-ences are important in valuing dentaltreatments. Events like losing teeth andgetting dentures are ranked high by indi-viduals in comparison with many otherlife events (14). Measures which try tocapture the patient's preferences havebeen used for long titne within healtheconomics, and the interest in tneasuringthe quality of life of dilTerent dental con-ditions has increased (15-17). Unsolvedproblems persist and the methods in thisstudy have to be considered as experi-mental. The measures do not replacecommonly used odontologic parametersbut might be considered as a comple-ment.

The use of the rating scale techniquein measuring health indexes can be ques-tioned. Health indexes used in economicevaluations should be tneasured by acardinal utility scale (18), making thestrength of the patient's preferences cor-rectly captured. Empirical evidence indi-cated that different scaling methods givedilTerent results and that the rating scaletechnique has to be corrected when usedin economic evaluations (18). However,consensus regarding scaling methods inthis matter is still not present (19). In thisstudy the correlation between oral healthand measuretnent as an index and as aprofile was good.

The results of the regression analysisdepend heavily on the functional form ofthe regression equation. The linearmultiplicative (log-log) functional formused has the property of diminishingmarginal rate of substitution. It also hasthe property that the dimensions rein-force each other. Both properties havesupport from economic theory (20).

The suggestion that oral health in-fiuences psychological and social reac-tions (21) is to some extetit supported byour data. However, the causal relation-ships are uncertain. Patients with psy-chological and social reactions mightvalue their oral state worse than others.Furthermore, we found Ihc correlationbetween the oral health index and thegeneral health index to be very weak.

Costs as well as oral health state aretime-dependent. According to our mea-sures of oral health the results of thetreatment were good. Our study periodwas on average 8 yr. Whether this is longenough is an open question. Further in-vestigations accounting both subjectiveand objective treatment results in rela-

tion to cost for alternative treatments areneeded.

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