Subjective intensity of painduring the treatment ofperiodontal lesions with theVectorTM-system

Andreas Braun, Felix Krause,Rolf Nolden, Matthias FrentzenDepartment of Operative Dentistry andPeriodontology, University of Bonn, Germany

The initial hygiene phase is funda-

mental to successful periodontal ther-

apy (1). The patient should be enabled

to optimize oral hygiene procedures

and to maintain healthy periodontal

tissues. The initial hygiene phase con-

sists of patient motivation and scaling

and root planing. Calcified hard

deposits on the teeth should be

removed completely, leaving smooth

and glass-hard surfaces (2). Using hand

instruments scaling and root planing is

a very efficient but time-consuming

procedure. For interproximal root

planing and removing overhanging

fillings oscillating systems (e.g. the

EVA system) are available (3). Sonic

and ultrasonic instruments are used to

mechanize the procedure of scaling and

root planing. Using these instruments

without efficient water cooling may

produce a considerable heat develop-

ment at the scaler’s tip. Thus, the tooth

might be exposed to temperatures ex-

ceeding its biological tolerance (4, 5).

Furthermore, the tactile sense of the

sonic or ultrasonic instruments is

restricted in comparison to hand

instruments (6).

The VectorTM-system generates

ultrasonic vibrations at a frequency of

25 kHz which are converted by a

resonating ring, so that a horizontal

vibration is deflected vertically. As a

result the instrument tip moves parallel

to the tooth surface. The liquid directed

to the VectorTM-instruments estab-

lishes indirect connection of ultrasonic

energy to the periodontal tissues. Gen-

erating an adhering film of water or

particle suspension around the instru-

ments, this principle is comparable to

ultrasonic cleaning baths or lithotriptor

systems. By avoiding vibrations applied

vertically on the root surface, the

treatment with the VectorTM-system

should be less painful than treatment

with conventional systems. A less

Braun A, Krause F, Nolden R, Frentzen M. Subjective intensity of pain during the

treatment of periodontal lesions with the VectorTM-system. J Periodont Res 2003;

38; 135–140. � Blackwell Munksgaard, 2003

The aim of this study was to measure subjective intensities of pain during the

treatment of periodontal lesions with the VectorTM-system when compared to pain

occurring during the treatment with conventional methods.

Twenty patients, each of whom had three teeth with comparable periodontal

pocket depths, were treated using three different methods: (i) scaling and root

planing with hand instruments, (ii) cleaning with a conventional ultrasonic

instrument (SirosonTMS) and (iii) cleaningwith theVectorTM-system.The subjective

intensities of pain during the treatment were measured with an intermodal intensity

comparison. A visual analog scale was used for the evaluation after the treatment.

The results of the intermodal intensity comparison during treatment showed

that the use of the VectorTM-system caused less pain than the cleaning with hand

instruments or the conventional ultrasonic system (P < 0.05). The intermodal

intensity comparisons of cleaning with hand instruments and cleaning with the

conventional ultrasonic system were not significantly different (P > 0.05). These

results could be confirmed by the visual analog scale.

Using the VectorTM-system for cleaning periodontal lesions it is possible to

reduce pain sensations compared to conventional methods. Using cleaning

methods that cause less discomfort and pain, it might be possible to increase the

patient’s compliance during non-surgical periodontal therapy and recall.

Dr Andreas BraunDepartment of Operative Dentistry andPeriodontology, University of Bonn,Welschnonnenstr. 17, D-53111 Bonn, GermanyTel: + 49 (0)228 287 2428Fax: + 49 (0)228 287 2444e-mail: a.braun@uni-bonn.de

Key words: non-surgical periodontal therapy;ultrasonic instrument; intermodal intensitycomparison; visual analog scale

Accepted for publication January 31, 2002

J Periodont Res 2003; 38; 135–140Printed in the UK. All rights reserved

Copyright � Blackwell Munksgaard Ltd

JOURNAL OF PERIODONTAL RESEARCH

ISSN 0022-3484

painful treatment might increase

patient-compliance and give a better

prognosis for periodontal therapy.

The aim of this study was to com-

pare subjective intensities of pain dur-

ing cleaning of periodontal lesions with

the VectorTM-System and conventional

methods. Both the patient’s current

sensations during the treatment and a

summarized judgment after the treat-

ment were evaluated. The patient’s

acceptance of the different methods of

periodontal treatment were classified,

as it strongly correlates with their

painfulness.

Materials and methods

Twenty patients, each of whom had

three teeth with comparable periodon-

tal pocket depths, were treated using

three different methods: scaling

and root planing (Gracey-curettes,

Hu-Friedy, Leimen, Germany), a

conventional piezo ultrasonic instru-

ment with scaler tip (SirosonTMS,

instrument N�3, Siemens, Bensheim,Germany) or the VectorTM-system

(Duerr Dental, Bietigheim-Bissingen,

Germany) (Figs 1, 2). The subjective

intensities of pain during the treatment

were measured with an intermodal

intensity comparison. The patient held

the bulb of a manometer (Speidel

and Keller, Jungingen, Germany) in

his left hand while the display was

observed with a camera (Fig. 3). The

patient was told to set the pressure of

his hand in proportion to the perceived

intensities of pain. The videotape with

the recorded display of the manometer

was evaluated in intervals of 1 s. The

subjective intensities of pain after the

treatment were measured with a visual

analog scale. Pain was assessed on an

interval scale ranging from 0, repre-

senting no pain or discomfort, to 10,

representing maximum pain and dis-

comfort. After each treatment, a new

paper-bow with the printed interval

scale was given to the patient, so that

he could not be influenced by the results

before. The sequence of the different

treatments was randomly assigned to

the patients by use of a computer

generated random number table. Teeth

with the following factors were inclu-

ded in the clinical trial: comparable

Fig. 1. VectorTM-system with suspension bag and handpiece.

Fig. 2. Handpiece of the VectorTM-system with inserted straight metal periodontal probe.

Fig. 3. Manometer used to measure subjective intensities of pain with an intermodal

intensity comparison.

136 Braun et al.

probing depth (‡ 3 mm), degree of in-flammation, recession, bone loss and

position of the teeth (front or side

teeth, upper or lower jaw).

For statistical analysis the intensities

of pain measured during each treatment

were assigned to a relative scale ranging

from 0 (beginning of the treatment) to

200 (end of the treatment). As not every

treatment was finished after 200 s, the

values used for statistical analysis were

computed, adapting the intervals

between the evaluated intensities of

pain. Normal distribution of the values

was analysed with the Shapiro–Wilk

test. To compare the effects of the dif-

ferent treatment methods on pain dur-

ing the treatment, analysis of variance

(ANOVA) with subsequent Scheffe test

(a ¼ 0.05) was used. Scores of the

Table 1. Pain scores during and after treatment with hand instruments, a conventional

ultrasonic system and the VectorTM-system

Pain scores during the treatment

(intermodal intensity comparison) [U]a

Hand instrument Ultrasonic device VectorTM-system

Mean value 30 30 5

Standard deviation 11 12 3

Number of teeth 20 20 20

Pain scores after the treatment (visual analog scale) [U]b

Hand instrument Ultrasonic device VectorTM-system

Mean value 4.2 3.7 1.1

Standard deviation 2.7 1.8 1.2

Number of teeth 20 20 20

Pain scores during the treatment were normally distributed, pain scores after the treatment

were not normally distributed (Table 2).aUnits of pain scores according to the scale of the manometer.bUnits of pain scores according to the visual analog scale.

Table 2. Statistical analysis of the pain scores correlated with hand instruments (HI), a conventional ultrasonic instrument (UI) and the

VectorTM-system

Shapiro–Wilk test (normal distribution)

Pain scores during the treatment Pain scores after the treatment

Hand instrument P < 0.05 P > 0.05

Ultrasonic device P < 0.05 P > 0.05

VectorTM-system P < 0.05 P < 0.05

Pain scores during the treatment

Analysis of variance (ANOVA)

Sum of squares Degrees of freedom Mean square F-value P-value

85869.4 2 42934.7 456.79 < 0.001

56112.8 597 93.99

Comparison of means (Scheffe test)

Comparison Significant difference Comparison Significant difference

HI:UI no

HI:VectorTM yes UI:VectorTM yes

Pain scores after the treatment

Kruskal–Wallis test

Sum of squares Degrees of freedom Mean square F-value P-value

7338.83 2 3669.41 19.79 < 0.001

10568.7 57 185.42

Comparison of mean ranks

Comparison Significant difference Comparison Significant difference

HI:UI no

HI:VectorTM yes UI:VectorTM yes

Pain scores during the treatment were normally distributed and analysed using a parametric test (a ¼ 0.05). Pain scores after the treatmentwere not normally distributed and analysed using a non-parametric test (a ¼ 0.05).

Subjective intensity of pain with VectorTM-system 137

visual analog scale were analysed using

a non-parametric test (Kruskal–Wallis

test) with subsequent comparison of

mean ranks (a ¼ 0.05), as these valueswere not normally distributed. Differ-

ences were considered as statistically

significant at P ¼ 0.05.

Results

The treatment with the VectorTM-sys-

tem was shown to be less painful than

the cleaning with hand instruments or

with the conventional piezo ultrasonic

system. The results of the intermodal

intensity comparison during the treat-

ment showed that the intensities of

pain occurring during treatment with

the VectorTM-system was signifi-

cantly lower than the intensities of

pain reported with the other sys-

tems (P < 0.05; Tables 1, 2). The

comparison of the intensities of pain

during the treatment with handinstru-

ments and conventional ultrasonic

instruments demonstrated that the

pain sensations did not occur con-

stantly (Fig. 4), but both median val-

ues and standard deviations were

similar (Fig. 5).

Treatment with the VectorTM-sys-

tem was never assessed to be as painful

as the treatment with the other meth-

ods (Fig. 4). These results could be

verified by the visual analog scale.

Scores for the VectorTM-system were

significantly lower than the scores for

hand instruments and for the conven-

tional ultrasonic system (Tables 1, 2).

Pain scores after treatment with hand

instruments and with the conventional

ultrasonic system were not statisti-

cally different, but both methods were

assessed to be more painful than the

treatment with the VectorTM-system

(Fig. 6, Table 2).

Discussion

In this study, treatment with the Vec-

torTM-system was less painful than

treatment with hand instruments or

with a conventional ultrasonic instru-

ment. The lower painful sensations

occurring during treatment with the

VectorTM-system could be the result

of the longitudinal movement of the

instrument tip.

Thus, the instrument does not move

vertically on the root surface. More-

over, the design of this instrument

ensures indirect connection of ultra-

sonic energy to the periodontal tissues.

The periodontal lesion is only treated

by cavitation or acoustic microstrea-

ming and not by the chipping action of

the tip (7, 8). Antimicrobial effects of

ultrasonication have been shown to be

species and energy dependent (9, 10).

Except for spirochetes, antimicrobial

effects of an ultrasonic scaler could not

be demonstrated for periodontopathic

hand instrumentultrasonic instrumentVectorTM-system

Pain scores [U]50

40

30

20

10

0

Fig. 4. Pain scores during treatment with hand instruments, a conventional ultrasonic

instrument and the VectorTM-system. Average representation for the 20 patients. Beginning

of the treatment at 12 o’clock position, running clockwise to the end. Lowest pain scores

during treatment with the VectorTM-system.

ultrasonic instrument

hand instrument

35

30

25

20

15

10

5

Pai

n sc

ores

[U]

VectorTM-system0

Fig. 5. Mean values and standard deviations of the pain scores during the treatment (mean

values ¼ center of the bubble; standard deviation ¼ radius of the bubble). Significant lowestpain scores during the treatment with the VectorTM-system (P < 0.05).

138 Braun et al.

bacteria (11, 12). Further studies are

needed to examine the VectorTM-sys-

tem’s efficiency in reducing subgingival

plaque and calculus.

Both objective and subjective meth-

ods for diagnosis of pain sensations in

humans were used (13). Evaluating the

VectorTM-system dental evoked po-

tentials representing objectively painful

sensations could not be recorded. The

cleaning of a periodontal lesion is not

an exact temporally defined and re-

producible peripheral stimulus, so that

characteristic dental potentials are not

distinguishable from the spontaneous

activity of the cortex. In the present

study, visual analog scales and inter-

modal intensity comparisons were

suitable to estimate the pain intensity.

Comparable to the manometer used in

this study another intermodal match-

ing technique called �finger span� wasdescribed (14). The device consisted of

two metal arms taped to the thumb

and index fingers of the subject. The

distance of the two arms was measured

with a potentiometer, whose output

voltage correlated to the subjective

intensities of pain. The finger spans

were used to measure dental pain

evoked by hydrostatic pressures or

cold stimulation to exposed dentin (15,

16). The advantage of this and similar

methods is that intensities of pain can

be recorded during the entire treat-

ment. For that purpose, the patient

was instructed to set the pressure of his

hand in proportion to the currently

perceived intensity of pain. Other

methods (e.g. the visual analog scale)

ask only for a patient’s summarized

assessment after the treatment. Using

these methods, short-term painful sen-

sations usually occurring during the

treatment of periodontal lesions can

only be recorded imprecisely. The ma-

nometer used in the present study is a

tool often used for intermodal intensity

comparisons. Stevens used a manome-

ter to set the pressure of a subject’s

hand in proportion to the intensity of

light and described the psychophysio-

logical law (17). In further studies the

intensities of heat, weight, cold, vibra-

tion and sound were evaluated using a

manometer (18). Another type of in-

termodal intensity comparison is used

frequently: rating the perception of

sensitivity by providing a mark on a

visual analog scale with units from 0 to

10 or 0 to 100 (19–21). In contrast to

the intermodal intensity comparison

with a manometer the visual analog

scale can only be used for a retrospec-

tive assessment of previous painful

sensations. Because of this, it is very

important to explain the visual analog

scale very precisely to the patient be-

fore treatment takes place. When a

patient does not know what he is to do

after the treatment and is not asked to

rate the sensations immediately, he

might not remember the painful sen-

sations exactly. Because of this in the

present study the painful sensitivity

experienced during treatment was rat-

ed on a visual analog scale immediately

after each treatment and not summa-

rized after cleaning the periodontal

lesions with all three methods. A scale

from 0 to 10 was used. The same rating

was used to assess the efficacy of

desensitizing exposed roots or of pain

reduction by local anesthesia (19, 20).

Using the VectorTM-system for

cleaning periodontal lesions it is pos-

sible to reduce painful sensations

occurring during conventional meth-

ods used to perform debridement of

subgingival lesions. Because of this,

the patient’s acceptance of this new

method is very good. Motivating

especially fearful and sensitive patients,

the VectorTM-system may enhance the

patient’s motivation and improve

the results obtained with the initial

periodontal therapy.

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