Jan Lindhe. Clinical Periodontology

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REGENERATIVE PERIODONTAL THERAPY • 675

Table 28-1. Clinical outcomes of GTR treatment of deep intrabony defects

Authors

Membranes

Gains in CAL ± SD (mm)

Residual PPD

SD (mm)

Becker et al. 1988 e-PTFE

4.5 ± 1.7 3.2 ± 1.0

Chung et at 1990

collagen

0.6 ± 0.6

Handelsman et at 1991

e-PTFE

4.0 ± 1.4 3.9 ± 1.4

Karsten et al. 1992

e-PTFE

1.0 ± 1.1 5.1 ± 0.9

Proestakis et al. 1992

e-PTFE

1.2 ± 1.3 3.5 ± 0.9

Quteish & Dolby 1992

collagen

3.0 ± 1.5 2.2 ± 0.4

Selvig et al. 1992

e-PTFE

0.8 ± 1.3

Becker & Becker 1993

e-PTFE

32 4.5

3.9 ± 0.3

Cortellini et al. 1993b

e-PTFE

4.1 ± 2.5 2.0 ± 0.6

Falk et al. 1993

polylactic acid

4.5 ± 1.6 3.0 ± 1.1

Cortellini & Rini-Prato 1994

rubber dam

4.0 ± 0.7 2.4 ± 0.5

Laurell et al. 1994

polylactic acid

4.9 ± 2.4 3.0 ± 1.4

Al-Arrayed et al. 1995

collagen

19 3.9

Chen et al. 1995

collagen

2.0 ± 0.4 4.2 ± 0.4

Cortellini et al. 1995c

e-PTFE

4.1 ± 1.9 2.7 ± 1.0

Cortellini et al. 1995c e-PTFE+titanium

5.3 ± 2.2 2.1 ± 0.5

Cortellini et al. 1995a

e-PTFE+FGG

5.0 ± 2.1 2.6 ± 0.9

Cortellini et al. 1995a

e-PTFE

3.7 ± 2.1 3.2 ± 1.8

Cortellini et al. 1995b

e-PTFE+fibrin

4.5 ± 3.3

Cortellini et al. 1995b

e-PTFE

3.3 ± 1.9

Mattson et al. 1995

collagen

2.5 ± 1.5 3.6 ± 0.6

Mattson et al. 1995

collagen

2.4 ± 2.1 4.0 ± 1.1

Mellado et al. 1995

e-PTFE

2.0 ± 0.9

Becker et al. 1996

polylactic acid

2.9 ± 2.0 3.6 ± 1.3

Cortellini et al. 1996c

polylactic acid

4.5 ± 0.9 3.1 ± 0.7

Cortellini et al. 1996b

e-PTFE

5.2 ± 1.4 2.9 ± 0.9

Cortellini et al. 1996b

polylactic acid

4.6 ± 1.2 3.3 ± 0.9

Gouldin et al. 1996

e-PTFE

2.2 ± 1.4 3.5 ± 1.3

Kim et al. 1996

e-PTFE

4.0 ± 2.1 3.2 ± 1.1

Murphy 1996

e-PTFE+ITM

4.7 ± 1.4 2.9 ± 0.8

Tonetti et al. 1996b

e-PTFE

5.3 ± 1.7

Banque et al. 1997

collagen

3.6 ± 2.2

3.9 ± 1.7

Caffesse et al. 1997

polylactic acid

2.3 ± 2.0 3.8 ± 1.2

Caffesse et a l . 1997

e-PTFE

3.0 ± 1 . 2 3.7 ± 1.2

Christgau et al. 1997

e-PTFE

4.3 ± 1.2 3.6 ± 1.1

Christgau et al. 1997

polyglactin

4.9 ± 1.0 3.9 ± 1.1

Falk et al. 1997

polylactic acid

203

4.8 ± 1.5

3.4±

1.6

Kilic et al. 1997

e-PTFE

3.7 ± 2.0 3.1 ± 1.4

Cortellini et al. 1998

polylactic acid

3.0 ± 1.7 3.0 ± 0.9

Eickholz et al. 1998

polylactic acid

3.4 ± 1.6 3.2 ± 0.7

Smith MacDonald et a].1998

e-PTFE

4.3 ± 2.1 3.7 ± 0.9

Smith MacDonald et al. 1998

polylactic acid

4.6 ± 1.7 3.4 ± 1.2

Parashis et al. 1998

polylactic acid

3.8 ± 1.8 3.5 ± 1.4

Tonetti et al. 1998

polylactic acid

3.0 ± 1.6 4.3 ± 1.3

Cortellini et al. 1999 polylactic acid

4.9 ± 1.8 3.6 ± 1.2

Pontoriero et al. 1999

Jiff. barriers

3.1 ± 1.8 3.3 ± 1.3

Sculean et al. 1999a

polylactic acid

3.4 ± 1.4 3.6 ± 1.3

676 • CHAPTER 28

Table

28-1

(contd)

Authors

Membranes

Gains in CAL ± SD (mm)

Residual PPD

SD (mm)

Dorfer et al. 2000

polylactic acid

4.0 ± 1.2 2.7 ± 0.7

Dorfer et al. 2000

polidiossanon

3.4 ± 1.9 3.1 ± 1.1

Eickholz et al. 2000

polylactic acid

3.9 ± 1.2 2.6 ± 1.0

Karapataki et al. 2000

polylactic acid

4.7 ± 0.7 4.2 ± 1.4

Karapataki et al. 2000

e-PTFE

3.6 ± 1.7 4.6 ± 1.3

Ratka-Kruger et al. 2000

polylactic acid

3.1 ± 2.3 4.7 ± 1.4

Zybutz et al. 2000

polylactic acid

2.4 ± 1.9

Zubutz et al. 2000

e-PTFE

2.4±

0.8

Cortellini & Tonetti 2001

diff. barriers

5.4 ± 1.2 3.3 ± 0.6

Cortellini et al. 2001 polylactic acid

3.5 ± 2.1 3.8 ± 1.5

Weighted mean

1283 3.8

1.7 3.4

1.2

FGG = Free gingival graft

ITM = Interproximal tissue maintenance

REGENERATIVE PERIODONTAL THERAPY • 677

Fig. 28-29. Intrabony defect on the mesial aspect of a left maxillary premolar treated with a bioabsorbable barrier

membrane. (a) Clinical attachment loss was 12 mm. (b) Radiograph showing the presence of a deep interproximal

intrabony defect approaching the apex of the tooth. (c) A 7 mm interproximal intrabony defect was measured after

flap elevation, defect debridement and root planing. (d) A bioabsorbable barrier membrane has been placed and su

tured to cover the defect. (e) At 1 year a 4 mm pocket depth and 5 mm clinical gain of attachment were recorded. (f)

The 1-year radiograph shows that the intrabony defect is almost resolved.

treated with GTR was 3.3 ± 1.8 mm (95% CI 2.8-3.6

mm), while the flap surgery resulted in a mean gain

2.1 ± 1.5 mm (95% Cl 1.8-2.4 mm). These clinical

results

strongly indicate that there is an added bene

ficial

effect of placing a barrier material over an in

trabony

defect in conjunction with surgery.

Factors affecting clinical outcomes of GTR in intrabony

defects

The results reported in Table 28-1 indicate that clinical

improvements beyond that of flap surgery can be

obtained by treating intrabony defects with GTR, but

they also suggest a great variability in clinical out-

comes among the different studies. In addition, it is

apparent from the results that the complete resolution

of the intrabony component of the defect is observed

only a minority of sites. A series of factors associated

with the clinical outcomes were identified using mul-

tivariate approaches (Tonetti et al. 1993a, 1995, 1996a,

Cortellini et al. 1994, Machtei et al. 1994). These studies

have evaluated three types of factors associated with

the

observed variability of the results:

patient factors

defect factors

Fig. 28-28. Intrabony defect on the mesial aspect of a right maxillary canine treated with a non-bioabsorbable bar

rier

membrane. (a) The pocket depth is 9 mm and the loss of clinical attachment 10 mm. (b) Radiograph showing the

presence of an interproximal intrabony defect. (c) After full thickness flap elevation, defect debridement, and

root

planing, a 4 mm intrabony defect is evident. (d) An e-PTFE non-bioabsorbable barrier membrane has been tai

lored,

positioned and tightly sutured around the teeth adjacent to the defect. (e) The flap has been repositioned and

sutured

to cover the membrane. Optimal preservation of the soft tissues has been accomplished with an intrasulcu

lar

incision. (f) After removal of the membrane at 5 weeks, the defect appears to be completely filled with newly

formed

tissue. (g) The treated site has been surgically re-entered after 1 year. The intrabony defect is completely

filled with

bone. (h) The 1-year radiograph confirms the complete resolution of the intrabony defect.

678 • CHAPTER 28

Table 28-2. Controlled clinical trials comparing clinical outcomes of GTR procedures with access flap proce-

dures in deep intrabony defects

CAL = Clinical attachment level

PPD = Probing pocket depth SD =

Standard deviation

3. factors associated with the GTR technique and the

healing period.

Patient factors

The level of self-performed plaque control had a para-

mount influence on the outcome of GTR. In fact, better

clinical attachment level gains were observed in pa-

tients with optimal levels of plaque control as com-

pared with those in patients with poor oral hygiene

(

Cortellini et al. 1994, Tonetti et al. 1995, 1996a). Pa-

tients with plaque on < 10% of the tooth surfaces (full

mouth plaque score, FMPS) had a gain of clinical

attachment which was 1.89 mm greater than that ob

served in patients with FMPS > 20% (Tonetti et al.

1995). The authors also demonstrated that cigarette

smoking was associated with reduced attachment

level gains. The attachment gain in subjects smoking

more than 10 cigarettes/day was 2.1 ± 1.2 mm versus

5.2 ± 1.9 mm in non-smokers (Tonetti et al. 1995).

Another important variable is the level of residual

periodontal infection in the dentition. The higher the

level of residual infection, the lower was the attach-

ment gain (Tonetti et al. 1993a, Machtei et al. 1994). It

can be concluded that patient selection is critical to the

success of GTR therapy (Fig. 28-30).

Defect factors

Defect morphology plays a major role in healing fol-

lowing GTR treatment of intrabony defects. This was

demonstrated in studies showing that the depth and

width of the intrabony component of the defect influ-

ence the amount of clinical attachment and bone

gained at 1 year. The deeper the defect, the greater was

the amount of clinical improvements, while the wider

the defect, the lower were the attachment and bone

gains (Garrett et al. 1988, Tonetti et al. 1993a, 1996a).

In a recent controlled study, however, it was dem-

onstrated that deep and shallow defects have the

same potential" for regeneration. In this study, deep

defects (deeper than 3 mm) resulted in larger linear

amounts of CAL gains than shallow defects (3.7 ± 1.7

mm versus 2.2 ± 1.3 mm), but the percentage of CAL

gains as related to baseline defect depth was similar

in deep (76.7 ± 27.7%) and in shallow (75.8 ± 45%)

Gains in CAL ± SD (mm) Residual PPD ± SD (mm)

Authors Membranes N GTR Access flap

GTR Access flap

Chung et al. 1990 collagen

0.6 ± 0.6

collagen 9 2.4 ± 2.1 4.0 ± 1.1

control

14 -0.7 ± 0.9

Proestakis et al. 1992 e-PTFE 9 1.2 ± 1.3 3.5 ± 0.9

control

9 0.6 ± 1.0 3.7 ± 3.0

Quteish & Dolby 1992 collagen

3.0 ± 1.5

2.2 ± 0.4

control

26 1.8 ± 0.9 3.4 ± 0.6

Al-Arrayed et al. 1995 collagen

19 3.9 2.5

control

14 2.7 3.5

Cortellini et al. 1995c e-PTFE

4.1 ± 1.9

2.7 ± 1.0

e-PTFE+titanium

15 5.3 ± 2.2

2.1 ± 0.5

control

15 2.5 ± 0.8

3.7 ± 1.3

Mattson et al. 1995 collagen 13 2.5 ± 1.5

3.6 ± 0.6

control 9 0.4 ± 2.1

4.5 ± 1.8

Cortellini et al. 1996b e-PTFE 12 5.2 ± 1.4

2.9 ± 0.9

polylactic acid 12 4.6 ± 1.2

3.3 ± 0.9

control

12 2.3 ± 0.8

4.2 ± 0.9

Tonetti et al. 1998 polylactic acid

3.0 ± 1.6

4.3 ± 1.3

control 67 2.2 ± 1.5

4.2 ± 1.4

Pontoriero et al. 1999 diff. barriers

3.1 ± 1.8

3.3 ± 1.3

control 30 1.8 ± 1.5

4.0 ± 0.8

Ratka-Kruger et at 2000 polylactic acid

3.1 ± 2.3

4.7 ± 1.4

control 21 3.3 ± 2.7

4.9 ± 2.1

Cortellini et al. 2001 polylactic acid 55 3.5 ± 2.1

3.8 ± 1.5

control 54 2.6 ± 1.8

4.7 ± 1.4

Weighted mean 584 3.3 ± 1.8 2.1 ± 1.5

3.5 ± 1.1 4.1 ± 1.3

REGENERATIVE PERIODONTAL THERAPY •

defects. The width of the intrabony component of the

defects is measured as the angle that the bony wall of

the defect forms with the long axis of the tooth. In a

recent study on 242 intrabony defects, Cortellini &

Tonetti (1999) demonstrated that defects with a radio-

graphic angle of 25° or less gained consistently more

attachment (1.6 mm on average) than defects of 37° or

more.

It was also shown that the number of residual bony

walls was related to the outcomes of various regenera-

tive approaches (Goldman & Cohen 1958, Schallhorn

et al. 1970). This issue as related to GTR therapy was

addressed in three investigations (Selvig et al. 1993,

Tonetti et al. 1993a, 1996a). In one study, the reported

1 year mean clinical attachment level gain was 0.8 ±

1.3 mm. This gain corresponded to the depth of the

three-wall intrabony component of the defect (Selvig

et al. 1993). In the other two investigations, on the

contrary, gains in attachment were not related to the

defect configuration in terms of one-wall, two-wall

and three-wall subcomponents (Tonetti et al. 1993a,

1996a). A total of 70 defects were examined in these

two latter studies, utilizing a multivariate approach.

The treatment resulted in mean attachment gains of

4.1 ± 2.5 mm and 5.3 ± 2.2 mm, and it was observed

that the most coronal portion of the defects which is

most susceptible to negative influences from the oral

environment were often incompletely filled with

bone.

The endodontic status of the tooth has also been

suggested as a potential relevant factor in periodontal

therapy. Emerging evidence (see Chapter 14) indicates

that root canal treated teeth may respond differently

to periodontal therapy. A clinical study on 208 con-

secutive patients with one intrabony defect each dem-

onstrated that root canal treatment does not nega-

tively affect the healing response and the long-term

stability of results of deep intrabony defects treated

with GTR (Cortellini & Tonetti 2000b). Finally, a con-

trolled clinical trial demonstrated that severe tooth

hypermobility can negatively affect the clinical out-

comes of regeneration (Cortellini et al. 2001). Based on

these results, it can be concluded that deep and narrow

intrabony defects at either vital or endodontically

treated teeth are the ones in which the most beneficial

outcomes can be achieved by GTR treatment (Fig.

28-31). Severe dental hypermobility may impair the

clinical outcomes.

Technical factors

Successful GTR requires careful flap design, correct

placement of the material, good closure of the wound

and optimal post-operative plaque control.

Membrane exposure is reported to be a major com-

plication with a prevalence in the range of 50 to 100%

(Becker et al. 1988, Cortellini et al. 1990, 1993b, Selvig

et al. 1992, 1993, Murphy 1995a, DeSanctis et al.

1996a,b, Falk et al. 1997, Trombelli et al. 1997, Mayfield

et al. 1998). Cortellini et al. (1995c,d) reported that the

prevalence of membrane exposure can be highly re-

duced with the use of access flaps, specifically de-

signed to preserve the interdental tissues (modified

papilla preservation technique) (Fig. 28-32).

Many studies have shown that the exposed mem-

branes are contaminated with bacteria (Selvig et al.

1990, 1992, Grevstad & Leknes 1992, Machtei et al.

1993, Mombelli et al. 1993, Tempro & Nalbandian

1993, Nowzari & Slots 1994, Novaes-Jr et al. 1995,

Nowzari et al. 1995, DeSanctis et al. 1996a,b). Con-

tamination of exposed non-bioabsorbable as well as

bioabsorbable membranes was associated with lower

probing attachment level gains in intrabony defects

(

Selvig et al. 1992, Nowzari & Slots 1994, Nowzari et

al. 1995, DeSanctis et al. 1996a,b). The impaired

clini-

Fig. 28-30. Diagram illustrating pa-

tient selection criteria. It can be

seen that control of local, behav-

ioral and systemic patient charac-

teristics may improve the treat-

ment outcomes. (Modified from

Cortellini & Bowers 1995).

FMPS = full mouth plaque score.

FMBS = full mouth bleeding score.

Fig. 28-32. (a) Left maxillary central incisor with a 10 mm pocket depth and 11 mm of clinical attachment loss on

the

mesial surface. A diastema is present between the two central incisors. (b) Full thickness buccal and palatal flaps

have been raised and an intrabony defect can be seen. The interdental papilla has been incised on the buccal

aspect

and elevated with the palatal flap (modified papilla preservation technique). (c) A titanium-reinforced

e-PTFE barrier

membrane has been placed and fixed close to the level of the cemento-enamel junction. (d) The membrane is

completely covered. This primary closure has been obtained by preserving the interdental papilla and

by coronal

displacement of the buccal tissue flap. (e) At 6 weeks, the membrane is completely covered with healthy tissue. (f)

After membrane removal at 6 weeks, dense newly formed tissue is evident in the defect and in the

supracrestal space

maintained by the titanium-reinforced membrane. (g) The newly formed tissue is completely

covered by the raised

and well preserved tissue flaps. (h) The photograph after 1 year shows a 4 mm residual pocket depth. A gain of

clinical attachment of 6 mm was recorded, and no recession has occurred compared to base-line. (j) 1 year

photograph showing the optimal preservation of the interdental tissues.

68o •

CHAPTER

Fig. 28-31. Diagram illustrating de-

fect selection criteria. It can be

seen that deep and narrow de-

fects, whether they are one-wall,

two-wall or three-wall defects,

have the greatest possibility to

show gain of attachment after

treatment. (Modified from Cortel-

lini & Bowers 1995.)

REGENERATIVE PERIODONTAL THERAPY • 681

Fig. 28-33. (a) At 5 weeks after treatment of an intrabony defect with a non-resorbable barrier membrane, the cover

ing tissue was largely dehiscent. After membrane removal, the flaps could not properly cover the newly formed

tissue. (b) A free gingival graft has been harvested from the palate and saddle shaped to fit the interdental space.

(c)

The free gingival graft is placed to cover the newly regenerated tissue. (d) The graft is kept in position by inter

rupted and suspended sutures. (e) Healing after 1 week. (f) Appearance of the treated site after 1 year.

cal results in some studies were associated with high

counts of bacteria and with the presence of P.

gingivalis

and A. actinomycetemcomitans

(Machtei et al. 1994,

Nowzari & Slots 1994, Nowzari et al. 1995).

Bacterial contamination of the membrane may oc-

cur during surgery, but also during the postoperative

healing phase. After placement, bacteria from the oral

cavity may colonize the coronal part of the membrane.

Frequently, this results in recession of the gingival

tissues, which allows colonization of the membrane

material further apically. In addition, "pocket" forma-

tion may occur on the outer surface of the membrane

due to apical migration of the epithelium on the inner

surface of the covering gingival tissue. This may allow

bacteria from the oral cavity to colonize the subgingi-

val area. The significance of bacterial contamination

was addressed in an investigation in monkeys (Sander

& Karring 1995). The findings of this study showed

that new attachment and bone formation occurred

consistently when bacteria were prevented from in-

vading the membrane and the wound during healing.

In order to prevent wound infection, some investi-

gators have administered systemic antibiotics to pa-

tients before and during the first weeks after mem-

brane application (Demolon et al. 1993, Nowzari &

Slots 1994). However, despite the application of sys-

temic antibiotics, occurrence of postoperative wound

infection related to implanted barrier membranes was

noticed. This indicates that either the drug adminis-

tered is not directed against the microorganisms re-

sponsible for the wound infection, or that the drug

does not reach the infected site at a concentration

sufficiently high to inhibit the target microorganisms.

An improved effect on periodontal healing after GTR

in association with local application of metronidazol

was reported by Sander et al. (1994). Twelve patients

with one pair of intrabony defects participated in the

study. Metronidazol was placed in the defects and on

the membrane prior to wound closure, while the con-

trols were treated with a membrane alone. Six months

following membrane removal the medium gain in

probing attachment level, presented as a percentage

of the initial defect depth, was 92% for test defects

versus 50% for the control defects. Other clinical pa-

rameters, like plaque index, bleeding on probing,

pocket depth reduction or recession of the gingival

margin were similar in the test and control sites. Al-

though the use of local or systemic antibiotics may

reduce the bacterial load on exposed membranes, it

seems ineffective in preventing the formation of a

microbial biofilm (Frandsen et al. 1994, Nowzari et al.

1995). Apart from the erythema and swelling related

to such infection of the wound, more severe postop-

erative complications such as suppuration, sloughing

or perforation of the flap, membrane exfoliation, and

post-operative pain have been reported (Murphy

1995a, b).

Another important issue associated with the clini-

cal results is the coverage of the regenerated tissue

after removal of a non-bioabsorbable membrane.

Many authors have reported that the frequent occur-

rence of a gingival dehiscence over the membrane is

likely to result in insufficient protection of the inter-

proximal regenerated tissue (Becker et al. 1988, Selvig

et al. 1992, Cortellini et al. 1993b, Tonetti et al. 1993a).

Exposure of the regenerated tissue to the oral environ

ment entails the risks of mechanical and infectious

insults which in turn may prevent complete matura-

tion of the regenerated tissue into a new connective

tissue attachment. In fact, incomplete coverage of the

regenerated tissue was associated with reduced at-

tachment and bone gain at 1 year (Tonetti et al. 1993a).

682 • CHAPTER 28

Fig. 28-34. (a,b) Left maxillary lateral incisor with a deep interproximal intrabony defect on the mesial surface. (c)

Flaps are raised according to the modified papilla preservation technique, and a titanium reinforced barrier mem-

brane is placed over the defect. (d) By coronal displacement of the flap and preservation of the interdental papilla,

the membrane is completely covered. (e,f) After 6 weeks of uneventful postoperative healing the membrane was re-

moved, (g) and the newly formed tissue was completely covered. (h) At 1 year, residual probing pocket depth was

mm and no buccal or interdental recession had occurred. (j) The baseline radiograph shows radiolucency ap-

proaching the apex of the tooth, but (k) after 1 year the intrabony defect is resolved and some supracrestal bone ap

position seems to have occurred (k). The radiograph taken at 6 years confirms the supracrestal bone regeneration

(

1) and the clinical image shows the integrity of the interdental papilla with optimal preservation of the esthetic ap

pearance (m).

Recently, the positioning of a saddle-shaped free gin-

gival graft over the regenerated interproximal tissue

(Fig.

28-33) was suggested (Cortellini et al. 1995a) to

offer

better coverage and protection than a dehiscent gingival

flap. In this randomized controlled study,

more gain of

attachment was observed in the 14 sites

where a free gingival graft was positioned after mem-

brane removal (5.0 ± 2.1 mm), than in the 14 sites

where a conventional protection of the regenerated

tissue

was accomplished (3.7 ± 2.1 mm).

In order to increase the space for regeneration, and

in order to achieve and maintain primary closure of

REGENERATIVE PERIODONTAL THERAPY •

683

the flap in the interdental area, the modified papilla

preservation technique (MPPT) was developed

(

Cortellini et al. 1995c,d). This approach combines

special soft tissue management with use of a self-sup-

porting titanium-reinforced membrane capable of

maintaining a supra-alveolar space for regeneration.

The MPPT allows primary closure of the interdental

space, resulting in better protection of the membrane

from the oral environment (Cortellini et al. 1995d). The

technique involves the elevation of a full thickness

palatal flap which includes the entire interdental pa-

pilla. The buccal flap is mobilized with vertical and

periosteal incisions, coronally positioned to cover the

membrane, and sutured to the palatal flap through a

horizontal internal crossed mattress suture over the

membrane. A second internal mattress suture war-

rants primary closure between the flap and the inter-

dental papilla. A representative case is shown in Fig.

28-34. In a randomized controlled clinical study on 45

patients (Cortellini et al. 1995c), significantly greater

amounts of attachment gain were obtained with the

MPPT (5.3 ± 2.2 mm), in comparison with either con-

ventional GTR (4.1 ± 1.9 mm) or flap surgery (2.5 ± 0.8

mm), demonstrating that a modified surgical ap-

proach can result in improved clinical outcomes.

In this study 100% of the sites were closed on top of

titanium-reinforced membrane and 73% remained

closed for up to 6 weeks, when the barrier membrane

was removed. The reported procedure can be success-

fully applied in sites where the interdental space width

is at least 2 mm at the most coronal portion of

the

papilla. When interdental sites are narrower, the

reported technique is difficult to apply. In order to

overcome this problem, a different papilla preservation

procedure (the simplified papilla preservation

flap) has

been proposed to apply in narrow interden

tal spaces (

Cortellini et al. 1999). This approach in

cludes an

oblique incision across the defect-associated

papilla,

starting from the buccal angle of the defect associated

tooth to reach the mid-interdental part of

the papilla at

the adjacent tooth under the contact point. In this way,

the papilla is cut into two equal parts of which the

buccal is elevated with the buccal

flap and the lingual

with the lingual flap. In the cited study, 100% of the

narrow interdental papilla could be

closed on top of

bioresorbable barriers, and 67% main

tained primary

closure over time, resulting in 4.9 ± 1.8

mm of clinical

attachment level gains. This approach

has been

successfully applied in different multicenter

randomized clinical trials designed to test the gener-

alizability of the added benefits of using barrier mem-

branes on deep intrabony defects (Tonetti et al. 1998,

Cortellini et al. 2001).

In the cited studies, GTR therapy of deep intrabony

defects performed by different clinicians on various

patient populations resulted in both greater amounts

and improved predictability of CAL gains than access

flap alone. The issue of soft tissue manipulation to

obtain a stable protection of the regeneration site has

been further explored, applying a microsurgical ap-

proach in the regenerative therapy of deep intrabony

defects (Fig. 28-35). In a patient cohort study on 26

patients with 26 intrabony defects treated with papilla

preservation techniques, primary closure on the bar-

rier was obtained in 100% of the cases and maintained

over time in 92.3% of the sites. Treatment resulted in

large amounts of CAL gains (5.4 ± 1.2 mm) and mini-

mal gingival recession (0.4 ± 0.7 mm). Thus, the im-

proved vision and better soft tissue handling im-

proved the predictability of periodontal regeneration.

Postoperative morbidity

To date, little consideration has been given to critical

elements that could contribute to the patient's assess-

ment of the cost-benefit ratio of GTR procedures.

These

include postoperative pain, discomfort, compli

cations,

and the perceived benefits from the treatment.

parallel group, randomized, multicenter and con-

trolled clinical trial designed to test the efficacy of GTR

and flap surgery alone assessed these patient issues

(

Cortellini et al. 2001). During the procedure, 30.4% of

the test and 28.6% of the controls reported moderate

pain and subjects estimated the hardship of the proce-

dure as 24 ± 25 units on a visual analog scale (VAS in

a scale from 0 to 100) in the test group and to 22 ± 23

VAS in the controls. Test surgery with membranes

required longer chair time than flap surgery (on aver-

age 20 minutes longer). Among the postoperative

complications, edema was most prevalent at week 1

and most frequently associated with the GTR treat-

ment, while postoperative pain was reported by fewer

than 50% of both test and control patients. Pain inten-

sity was described as mild and lasted on average 14.1

± 15.6 hours in the test patients and 24.7 ± 39.1 hours

in the controls. Postoperative morbidity was limited

a minority of subjects: 35.7% of the test and 32.1%

the controls reported that the procedures interfered

with daily activities for an average of 2.7 ± 2.3 days in

the test group and 2.4 ± 1.3 days in the control group.

These data indicate that GTR adds almost 30 minutes

to a flap procedure and is followed by a greater preva-

lence of post surgical edema, while no difference could

be observed between GTR and flap surgery alone in

terms of postoperative pain, discomfort and interfer-

ence with daily activities.

Furcation involvements

The invasion of the furcation area of multirooted teeth

by periodontitis represents a serious complication in

periodontal therapy. The furcation area is often inac-

cessible to adequate instrumentation, and frequently

the roots present concavities and furrows which make

proper cleaning of the area impossible (see Chapter

29)

. As long as the pathologic process is extending

only a

minor distance (< 5 mm; degree I and II involve

ments)

into the furcation area, further progress of the

disease

can usually be prevented by scaling and root

planing,

provided a proper oral hygiene program is

established

after treatment. In more advanced cases

(5-6 mm;

degree II involvements), the initial cause-re-

684. • CHAPTER 28

Fig. 28-35. (a) Right first maxillary premolar with a 7 mm pocket on the mesial surface. The interdental space (b) is

very narrow (> 2 mm), and is accessed with a simplified papilla preservation flap. The 5 mm deep intrabony defect

(

c) is covered with a bioresorbable barrier membrane (d). Primary closure of the flap over the membrane (e,f) is

maintained over time (g,h). After 1 year the interdental papilla is completely preserved and the residual pocket

depth is 3 mm (j,k). The radiograph taken at baseline (1) compared with that taken 1 year after treatment (m) shows

that the intrabony defect has healed completely.

lated treatment is frequently supplemented with sur-

gery involving contouring of the interradicular bone

(

osteoplasty) or reduction of the tooth prominence at

the furcation entrance by grinding (odontoplasty), in

order to reduce the horizontal extension of the furca-

tion involvement. In cases where the involvement is

extending deeper into the furcation area (> 5 mm;

degree II involvements), or a through and through

defect (degree III involvements) has developed, tun

nel

preparation or root resection has been advocated

the choice of treatment. However, both of these

latter

treatments involve a risk of complications on a

long-

term basis. Following tunnel preparation, caries

frequently develops in the furcation area and root

resected teeth often present complications of non-peri

odontal nature, although controversial reports exist

regarding the long-term results of these treatment

modalities (Hamp et al. 1975, Langer et al. 1981, Er-

penstein 1983, Biihler 1988, Little et al. 1995).

Considering the complexity of current techniques

for the treatment of furcation problems, and in view

of the long-term results and complications reported

following treatment of advanced furcation involve-

ments by traditionally resective therapy, predictable

regeneration of the periodontium at furcation-in-