Jan Lindhe. Clinical Periodontology

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CAUSE-RELATED PERIODONTAL THERAPY • 435

Fig. 20-6. (a) Photograph illustrating the lingual aspect of the mandibular front tooth region with supragingival

plaque and calculus. (b) The same tooth region 3 weeks after supragingival scaling and institution of proper oral

hygiene. (c) Radiographs of left maxilla before and after removal of calculus and amalgam overhangs.

tion is dependent on the material and geometry of the

edge, the sharpness of the edge and the forces used

during instrumentation (Lindhe 1964). Even if sub-

gingival scaling and root planing often are regarded as

two separate procedures with different objectives (see

definition), in clinical work they cannot always be

separated from each other.

Subgingival instrumentation aims at resolving the

inflammation in the gingiva and arresting the progres

sive destruction of the attachment apparatus by re-

moving the biofilm present in the gingival pocket.

Coupled with an effective supragingival plaque con-

trol program, therefore, subgingival debridement is

the most important measure in the treatment of peri-

odontitis. As a matter of fact, in many patients who

adopt proper self-performed plaque control habits,

subgingival instrumentation results in gingival health

(

Fig. 20-7).

Prior to the start of subgingival instrumentation,

the presence and extent of gingivitis and breakdown

of the supporting apparatus in all parts of the denti-

tion must have been properly assessed (see Chapter

18). Depending on the severity of the case, and the skill

of the operator, the number of teeth that may be in-

cluded in each treatment session of subgingival scal-

ing and root planing may vary. As a general rule, in a

patient with moderate/severe periodontitis, each ses-

sion should not involve treatment of more than one

quadrant.

The subgingival instrumentation should prefer-

ably be performed under local anesthesia. The root

surface of the diseased site is first explored with a

probe to identify (1) the probing depth, (2) the anat-

omy of the root surface (irregularities, root furrows,

open furcation, etc.), and (3) the location of the calci-

fied deposits.

When all root surfaces selected for treatment in a

given session have been examined, the order in which

the various sites are to be instrumented is determined.

The curette is inserted into the first pocket. The instru

ment is held in a so-called

modified pen grasp

and with

finger rest -

fourth finger rest or third finger rest - with

the face of the blade parallel to and in light contact

with the root surface (Fig. 20-8). It is important that all

root surface instrumentation is performed with a

proper finger rest. This implies that one finger - the

third or the fourth - must act as a fulcrum for the

movement of the blade of the instrument. A proper

finger rest should (1) provide a stable fulcrum, (2)

permit optimal angulation of the blade, and (3) enable

the use of wrist-forearm motion. In addition, to opti-

mize instrumentation and to avoid undue tissue dam

age, the finger rest must be secured as close as possible

to the particular root surface selected for treatment.

After the base of the periodontal pocket has been

identified with the distal edge of the blade, the instru-

ment is turned into a proper "cutting" position (Fig.

20-9). The grasp of the instrument is tightened, the

436 • CHAPTER 20

Fig. 20-7a-d. Photographs illustrating the effect of scaling, root planing and proper self-performed plaque control

on the gingival tissues. Note gingival recession and the stippled outer surface of the gingiva after treatment (b,d)

compared to the status before treatment (a,c).

force between the cutting edge and the root surface is

increased, and the blade is moved in a firm stroke

(

working stroke) in coronal direction. Due to the struc-

tural and chemical composition of root cementum and

dentine, the cutting operation

should always be initiated

at the bottom of the pocket and be guided in coronal direc-

tion.

In this movement the edge is moved into the root

surface, and root substance with attached calculus is

removed. The working stroke is followed by a finish

ing

stroke which will produce a smooth root surface.

Working and finishing strokes must be made in differ-

Fig. 20-8. Schematic illustration demonstrating the

proper "third finger rest" using a modified pen grasp

in the molar region in the left mandible.

ent directions to cover all aspects of the root surface

(

crosswise, back and forth) but, as stated above, the

strokes should always start from an apical position

and be guided in coronal direction. After the

working

and

finishing strokes

have been made, the probe is

inserted in the pocket again and the surface of the root

surface assessed anew. The root surface is considered

properly treated when the operator, using a periodon-

tal probe, finds the surface "smooth" and "hard".

The importance of removing "diseased" cementum

during root planing was questioned by several

CAUSE-RELATED PERIODONTAL THERAPY .

437

Fig. 20-9. (a) The curette is in-

serted into the periodontal pocket.

Note the close-to-zero degree an-

gulation of the face of the curette

against the root surface to facili-

tate the accessibility of the pocket.

(b)

The bottom of the periodontal

pocket is identified with the distal

edge of the blade of the curette.

(c)

The curette is turned to a

proper cutting position for scal-

ing. (d) The blade is moved along

the root surface in a scaling stroke

to remove calculus.

authors. Nyman et al. (1986, 1988) monitored the out

come of surgical periodontal therapy at sites where

the teeth were exposed to either extensive root instru-

mentation to remove all of the cementum and some

dentin, or gentle removal of plaque to leave most of

the root cementum. The authors found that in patients

with proper self-performed plaque control, both pro-

cedures allowed for excellent soft tissue healing. This

observation was confirmed by Oberholzer et al. (1996)

who concluded – from a clinical study – that the

establishment of a smooth and hard root surface was

not a critical factor in periodontal therapy. This means

that "overinstrumentation" also during non-surgical

therapy may cause more harm than good.

In this context it must also be realized that the

complete removal of subgingival plaque and calculus

in a "non-surgical" procedure is difficult if not impos-

sible. Waerhaug (1978) first assessed the pocket depth

of periodontally involved teeth that were sub-

sequently exposed to comprehensive scaling and root

planing. Following the completion of this treatment,

which was carried out by a skilled periodontist, the

teeth were extracted and the root surfaces examined

under the microscope. It was concluded that at sites

with a pocket depth of > 5 mm, subgingival scaling

and root planing in most cases (about 90%) left depos

its of plaque and calculus behind. A similar conclusion

was reached by, for example, Rabbani et al. (1981) and

Magnusson et al. (1984), and also by Sherman et al. (

1990) who in a clinical study demonstrated that

closed" subgingival instrumentation was a proce

dure

which consistently failed to eliminate all deposits

calculus. In their study, periodontally involved

teeth

were first exposed to subgingival scaling and

root

planing. Following the completion of this treat

ment,

soft tissue flaps were elevated to expose the root

surfaces. The authors observed that small remnants of

calculus had been left behind in several locations.

The studies quoted above imply that residual

plaque and calculus may remain even after careful

and repeated subgingival instrumentation. It is there-

fore the responsibility of the clinician to monitor treat

ment outcome. If a site fails to heal properly, i.e.bleed

ing on probing persists, and if the clinical attachment

level in deep pocket sites is not improved, additional

therapy such as access flap surgery must be consid-

ered. The reason for this is that findings by, for exam

ple, Eaton et al. (1985) and Caffesse et al. (1986) have

shown that scaling during access therapy may im-

prove the efficacy of root instrumentation.

' CHAPTER 20

Fig.

20-10. A

tooth has been subjected to subgingival

scaling and root planing and extensive tooth substance

has been removed due to repeated intense instrumenta

tion (arrow a). However, the periodontal pocket was

not

properly diagnosed and calculus has been left (ar

row

b).

Fig.

20-11.

The sharpness of a curette is tested on a plas

tic stick.

chip (arrow) is easily produced by a sharp

instrument.

Fig. 20-10 shows a tooth that has been subjected to

repeated scaling and root planing. The clinician did not,

however, reach the bottom of the periodontal

pocket,

plaque and calculus were left behind, the periodontitis

lesion progressed and the tooth eventually

had to be

extracted.

Factors important for the outcome of subgingival

instrumentation

Root anatomy:

The surface of a single-rooted tooth is

often easier to reach by subgingival instrumentation

than the furcation complex of multirooted teeth. How-

ever, concavities and tooth furrows exist in booth

single and multirooted teeth. Such root irregularities

may contain small deposits of plaque and calculus

which are difficult to reach. In such sites ultrasonic

instruments with specially designed tips may facili

tate

local therapy (Kocher & Plagmarm 1997). The

technical problems inherent in subgingival instru-

mentation increase with increasing probing depth.

Specially designed instruments with a long shank

(Fig.

20-3) may be used in deep pockets.

Skill of the operator:

The outcome of the subgingival

instrumentation is "operator sensitive". Thus, the

technical skill of the dentist/dental hygienist influ-

ences the result of this procedure. Brayer et al. (1989)

demonstrated that experienced dentists were more

efficient in subgingival debridment than more inexpe-

rienced operators. The difference between the two

categories of therapists was most pronounced in the

treatment of deeper (> 6 mm) pocket sites. Also, in

surgical therapy the technical skill of the operator

remains important for the outcome of the root de-

bridement part of the treatment.

Time allowed:

The time allowed for the instrumentation

will also influence the treatment result. In a study by

Badersten et al. (1981) it was demonstrated that as

much as 6-8 minutes were required for a comprehen-

sive subgingival treatment of one single tooth when

hand instruments were used. When ultrasonic instru-

ments were used 4-6 minutes were required.

Instrument sharpening

The hand instruments must have proper cutting edges

Fig. 20-12. Schematic drawing illustrating the sharpen

ing of a curette. The original geometry of the cutting

edge must be maintained during the sharpening proce

dure.

CAUSE-RELATED PERIODONTAL THERAPY • 439

in order to make subgingival instrumentation a pre-

cise and efficient procedure. A curette with a blunt

cutting edge

must be pressed

against the root surface

with a larger force than is required when a sharp

instrument is used. Scaling with instruments with

blunt cutting edges often results in an incomplete

removal of calculus but in the establishment of a

smoothened" root surface. Remaining calculus on

such a "smoothened" root surface is difficult to detect

with a periodontal probe. The cutting edge of the hand

instrument, therefore, must be controlled repeatedly

during scaling. This can be done by planing a plastic

stick (Fig. 20-11).

The sharpening of hand instruments can be per-

formed by the use of either "rotating" (cylindrical or

cone-shaped) or "plain" stones (India or Arkansas

stones). Curettes and sickles are sharpened by grind-

ing the lateral surfaces and/or the face of the blade. It

is important that the original geometry of the instru-

ment is not changed by the sharpening procedure (Fig.

20-12).

Ultrasonic and sonic instruments

For many years ultrasonic scalers (e.g. Cavitro

, Am

dent

, Odontosonl have been used for the removal

plaque, calculus and stain. Scaling with ultrasonic

instruments often results in the establishment of an

uneven root surface. It has been suggested, therefore,

that ultrasonic scaling should be supplemented with

hand instrumentation to establish a smooth root sur-

face (Bjorn & Lindhe 1962). Clinical studies have

evaluated the effect of scaling using ultrasonic or hand

instruments (Torafson et al. 1979, Badersten et al.

1981). The authors found that debridement of 4-7 mm

pockets with ultrasonic instrumentation was as suc-

cessful for healing diseased periodontal sites as was

scaling with hand instruments (curettes). It has also

been questioned whether indeed

smooth

root surface

after treatment is important for successful healing

(

Rosenberg & Ash 1974). Waerhaug (1956) found that

junctional epithelium readapted and a normal "epi-

thelial cuff" also formed to uneven root surfaces. Prop

erly used, therefore, ultrasonic instrumentation must

be regarded as a valuable substitute for conventional

scaling with hand instruments and may even be the

best instrument for scaling at furcation areas (Leon &

Vogel 1987).

Recently a new type of instrument for tooth de-

bridement was introduced —

the sonic scaler (e.g.

Titan

Micro-Mega Air Scaler

). This instrument is air-

driven and produces vibrations in the sonic range

(

2300-6300 cycles per second). In an

in vitro

study (Lie

& Leknes 1985) and in clinical studies (Loos et al. 1987,

Baehni et al. 1992) it was shown that the sonic scaler

was as effective for calculus removal as the ultrasonic

instrument and, besides, the sonic scaler caused less

root surface roughness than the ultrasonic device.

The removal of plaque and calculus by ultrasonic

and sonic instrumentation is accomplished by (1) the

vibration of the tip of the instrument, and (2) the

Fig. 20-13. The tip of the ultrasonic instrument. Note

the spraying and cavitation of the fluid used for cool

ing.

spraying and cavitation effect of the fluid coolant. The

vibrations (amplitude ranging from 0.006-0.1 mm) in

the ultrasonic instruments are produced by a metal

core which can change its dimension in an electromag

netic field with an operating frequency between 25

000

and 42 000 cycles per second. In the sonic

instruments,

the vibrations are generated

mechanically. During the

generation of the ultrasonic

vibrations heat is pro

duced, which is why the tip

during instrumentation

always has to be irrigated

with a coolant.

Before use, the ultrasonic instrument must be ad-

justed regarding the power (tuning) and cooling ac-

cording to the manual (Fig. 20-13). The tip should be

applied to the tooth surface with very light pressure

and be moved back and forth over the surface in

sweeping movements and in such a way that its pat-

tern of vibration is orientated parallel to the tooth

surface. This will prevent damage to the root. A peri-

odontal probe should always be used to check the root

surface characteristics after instrumentation.

A novel, diamond-coated,

sonic scaler insert was

introduced by Kocher & Plagmann (1997) The authors

claimed that this type of insert facilitated scaling and

root planing in furcation areas.

Rotating instruments

Root furrows, furcation areas and root surfaces in

deep, narrow, infrabony pockets are difficult to prop-

erly debride with the use of hand instruments. At such

sites, therefore, rotating instruments such as fine-

grained diamonds (or sonic scalers with diamond-

Fig. 20-14. A fine-grained diamond for mechanical de

bridement. Magnification x 1.5.

440 • CHAPTER 20

Fig. 20-15. (a) A diamond tip inserted in a handpiece (The Profin

Directional System). Arrows indicate the direc-

tions of the movement. (b) A set of tips (Lamineer

) of different design.

Fig. 20-16. (a) A collection of the PER-IO-TOR

instrument tips for scaling and root planing. (b) A schematic illustra-

tion of the effect of the PER-IO-TOR

instrument on the root surface with deposits (left). When the root cementum is

clean and planed, no more cementum can be removed because of the design of the instrument (right).

Fig. 20-17. Amalgam restorations before (a) and after (b) the adjustment of the overhangs. The buccal restoration in

tooth 46 is prepared in order to reduce the degree of furcation involvement.

coated inserts, see above) can be used (Fig. 20-14). Care

should be taken, however, to avoid excessive removal

tooth substance with such cutting procedures.

Reciprocating instruments

The Profin

Directional System offers a specially de-

signed handpiece (a second generation of the so called

Eva

system which was introduced in 1969) with a 1.2

mm reciprocating motion of the working tips set in

self-

steering or fixed mode (Fig. 20-15). A recom

mended

engine speed of 10 000-15 000 rpm will give

20 000-30

000 tip strokes per minute. Specially de-

signed working

tips have been developed for the

Profin Directional

System (Axelsson 1993). The PER

IO-TOR

instruments

will optimize cleaning and

planing of rough root

cementum surfaces and prevent

CAUSE-RELATED PERIODONTAL THERAPY • 441

further removal of root cementum once the surface is

clean and smooth (Fig. 20-16). Mengel et al. (1994)

evaluated the PER-IO-TO

instruments in an

in vitro

study. They stated that the PER-10-TOR" instruments

have similar planing properties as manual hand in-

struments, but cause minimal removal of tooth struc

tures.

Laser instruments

Laser instruments have been used in dentistry for

cavity preparation since 1964 and for root debride-

ment in combination with periodontal surgery. In a

recent clinical study by Schwarz et al. (2001), the

Er:

YAG (erbium-doped:yttrium, aluminium and gar-net

laser) was used for "closed" subgingival scaling

and

root planing. The laser treatment was compared

conventional instrumentation with curettes. The

authors concluded that the laser method gave better

results in terms of pocket reduction at sites with deep

pockets. Further studies are needed, however, to

evaluate the laser instrument and the long-term out-

come of this kind of treatment.

Removal of plaque-retention factors

In an epidemiological study Bjorn et al. (1969, 1970)

observed that ill-fitting artificial crowns and fillings

were associated with a reduced height of the peri-

odontal bone level. Jeffcoat & Howell (1980) reported

that marginal bone loss was more pronounced around

teeth with overhanging amalgam restorations than

around teeth without restorations. Rodriguez-Ferrer

et al. (1980) concluded that "the presence of a sub-

gingival overhanging defective margin may be the

only

important clinically significant feature of an

amalgam

restoration related to the pathogenesis of

chronic

inflammatory periodontal disease". It is not

the

overhang of the restoration

per se,

however, which

causes or maintains periodontal disease. Waerhaug

(

1960) pointed out that the more advanced gingival

inflammation observed in sites with ill-fitting restora-

tions was the result of extensive plaque accumulation

and not of mechanical or chemical irritation caused by

the filling material. Thus, overhangs of restorations

must be removed to (1) facilitate the removal of plaque

and calculus, and (2) to establish an anatomy of the

tooth surface which facilitates self-performed tooth

cleaning.

Overhanging margins of dental restorations can be

removed using a flame-shaped diamond stone

mounted on a handpiece for rotator movements, or a

flat diamond stone mounted on a handpiece for hori-

zontal reciprocal movements (Eva-system'

, Profin

Directional System) (Fig. 20-15). The overhang is re-

moved and the restoration is given a proper form and

smooth surface. The triangular or V-shaped tips

(

Lamineer

) are appropriately tailored for use in nar-

row interproximal spaces and can reach 2-3 mm sub-

gingivally for the reshaping and polishing of restora-

tions (Fig. 20-15b).

The adjustment of an improperly designed filling

artificial crown is often a difficult and time-consuming

procedure. It is sometimes more convenient to

remove the improper filling (crown) and insert a new

one with a proper marginal fit. Fig. 20-17 illustrates

the effect on the periodontal tissues of the adjustment

of an amalgam overhang.

HEALING AFTER

INITIAL,

CAUSE-RELATED THERAPY

Clinical measurements

The potential of subgingival instrumentation to elimi-

nate inflammation and arrest progression of peri-

odontal disease was studied in a number of early

clinical trials, e.g. Lovdal et al. (1961), Suomi et al.

(

1971), Axelsson & Lindhe (1978, 1981), Hirschfeld &

Wasserman (1978), Morrison et al. (1980), Badersten et

al. (1984).

Lovdal et al. (1961) examined around 1500 indi-

viduals in Norway regarding their oral hygiene status,

gingival conditions, alveolar bone loss and tooth loss.

The patients were subsequently, on an individual ba-

sis, given careful oral hygiene instruction, including

Fig. 20-18. The patients were divided into three groups

after the initial examination according to their oral hy

giene, "good", "fairly good", "not good". During a 5-

year period the patients were subjected to scaling and

root planing measures two to four times per year. In all

three categories of patients there was a remarkable im

provement of gingival conditions after 5 years of re-

peated plaque control measures. Data from Lovdal et

al. 1961.

442 • CHAPTER 20

Fig. 20-19. Histogram showing the

frequency distribution of inflamed

gingival units in the test and con

trol groups at the baseline (open

bars) and re-examinations after 3

and 6 years (hatched and black

bars respectively). The individual

mean (total) figures describe unal

tered gingival conditions in the

control groups but marked im-

provements in the test groups dur

ing the trial. Data from Axelsson

& Lindhe 1981.

detailed information in the proper use of toothbrush,

toothpick, dental floss, etc. In addition, their teeth

were subjected to meticulous supra and subgingival

scaling and root planing. The oral hygiene instruction

as well as the scaling and root planing measures were

repeated two to four times per year over a 5-year

period, at the end of which the patients were re-exam

ined. The authors reported (Fig. 20-18) that "the com-

bined effect of subgingival scaling and controlled oral

hygiene definitely reduced the incidence of gingivitis

and tooth loss". The improvement was remarkable

also in patients whose home-care habits did not im-

prove during the 5 years of trial. Similar findings were

reported by Suomi et al. (1971) from a study compris-

ing about 350 subjects in California. A test group of

patients received, during a 3-year period, oral hygiene

instruction and scaling three to four times per year,

while a control group during the same period received

restorative oriented dental care. At the end of the 3

years the test group patients had significantly less

gingivitis and less attachment loss than the controls.

Axelsson & Lindhe (1978, 1981) compared the effect

of a prophylactic program including (1) oral hygiene

control and (2) scaling and root planing repeated once

every 2-3 months over a 6-year period with the effect

of traditional dental therapy, i.e. a therapy which was

directed towards the symptoms of dental disorders

rather than towards the elimination of the etiological

factors. It was observed that in the patients of the

control groups there was only a minor improvement

in oral hygiene, while in the test groups at the re-ex-

aminations after 3 and 6 years, the mean plaque scores

were consistently low (< 20%). In the control groups

there was no improvement of the gingival conditions (

Fig. 20-19), while in the test groups the gingivitis

scores had approached 0 values (meaning gingival

health) at the re-examinations. Fig. 20-20 gives the

attachment level alterations that occurred between

1972 and 1978. It can be seen that, while in the patients

of the control groups there was a substantial further

loss of attachment, in the test patients there was no

further breakdown of the attachment apparatus.

Hirschfeld & Wasserman (1978) presented a long-

term survey of tooth loss in 600 patients treated for

periodontal disease. The patients were re-examined at

an average of 23 years after the active treatment, which

included primarily subgingival scaling, and root plan-

ing followed by careful maintenance therapy. The

authors observed that "during the post-treatment pe-

riod 300 patients had lost no teeth from periodontal

disease", and "199 had lost 1-3 teeth". This means that

periodontal therapy directed towards the elimination

of the subgingival infection using a non-surgical ap-

proach can be effective in preventing tooth loss in

most patients and also in those with advanced peri-

odontal disease.

Morrison et al. (1980) studied the short-term effect

of non-surgical treatment in 90 subjects with moder-

ately advanced periodontal disease. Following an in-

itial examination the patients were given oral hygiene

instruction and the pockets were treated by subgingi-

val scaling and root planing. Re-examination per-

formed 4 weeks after active therapy revealed that (1)

the patients had improved their oral hygiene, (2) the

gingivitis scores had decreased, and (3) the initial

depth of the periodontal pockets was substantially

CAUSE-RELATED PERIODONTAL THERAPY • 443

Fig.

20-20.

Histogram illustrating the alterations in the

clinical attachment levels between the baseline

(1972)

and re-examinations

(1975, 1978)

in various test and

control groups. The attachment level remained unal-

tered in the test groups but was reduced in all the con

trol groups (below the 0-line). The average attachment

loss per year in control groups was: I: 0.13 mm, II:

23mm, III: 0.26 mm. Data from Axelsson & Lindhe

1981.

reduced (Fig. 20-21). The authors concluded that al-

ready, 1 month following cause-related periodontal

therapy, the clinical severity of periodontal disease

was

markedly reduced.

Badersten et al. (1984) studied the effect of sub-

gingival scaling and root planing in 16 patients with

moderate-advanced periodontitis. The patients re-

ceived oral hygiene instruction and all single-rooted

teeth were exposed to meticulous subgingival de-

bridement using either handscalers or an ultrasonic

device. Re-examination carried out after 2 years

Fig. 20-21. Histogram describing the reduction of prob

ing depth 4 weeks after active therapy comprising scal

ing and root planing. Data from Morrison et al.

1980.

Table 20-1. The mean probing reduction and prob-

ing attachment gain/loss (mm) that can be expected

following scaling and root planing in non-molar

sites

showed that this treatment had resulted in the establ-

ishment of healthy gingival conditions (only about

10%, of the gingival sites bled on probing) and in a

marked reduction in the overall probing depth (Fig.

20-

22; Badersten 1984). The authors concluded that

careful subgingival scaling and root planing was an

effective means to eliminate gingivitis and reduce the

probing depth even at sites with initially very deep

(> 9

mm) periodontal pockets. Similar observations

have

also been reported in later clinical studies (for

review

see Cobb 1996).

It may be concluded that in patients who adopt

proper oral hygiene measures:

• Healing after non-surgical therapy seems to be com-

plete after about 3-6 months

•

The number of sites that bleed on probing will be

markedly reduced

•

More gingival recession and gain of probing attach-

444 • CHAPTER 20

Dimensional

changes for sites with different initial

probing

depths

* Interpretation: For sites initially 8-8.5 mm deep, gingival recession amounted to about 2mm, gain of probing attachment to 1 mm

and residual probing depth to 5 mm.

Fig. 20-22. Histogram illustrating clinical results after non-surgical periodontal therapy. Data from Badersten et al

1981, 1984.

Fig. 20-23. A schematic illustration of a gingival unit (a) before and (b) after periodontal therapy. Probing depth

measurements (blue lines) before (a) and after (b) therapy. The dotted line indicates the "histologic" attachment

level. Recession = green line. Location of the gingival margin before therapy (A) and after therapy (B). ICT = infil-

trated connective tissue, NCT = non-infiltrated connective tissue.

ment will be obtained in initially deeper than more • In sites with initial pockets of < 3 mm, a probing

shallow

pocket sites. See Fig. 20-22 and Table 20-1.

attachment loss of 0.5 mm will occur.

• In sites with initial probing depths of 6-9 mm, the

residual probing depth will be 4-5 mm, and the

amount of gingival recession about 2 mm.