Jan Lindhe. Clinical Periodontology

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PROCEDURES USED TO AUGMENT THE DEFICIENT ALVEOLAR RIDGE • 907

Fig. 39-29. Clinical picture of a 25-year-old woman demonstrating the presence of an edentulous ridge with ad

vanced bone loss at sites 11, 12 and 13. (b) Periapical radiograph demonstrating the bone defect and a

horizontal

root fracture at the middle of the root of tooth 14.

Fig. 39-30. A mucoperiosteal flap was raised both buc

caly and palatally. A 20 mm long titanium screw was

positioned, projecting from the bone crest.

Patient 3 - Alveolar ridge augmentation for

implant restoration of multiple adjacent

maxillary teeth

A 25-year-old woman had lost teeth 11, 12 and13 and

fractured the root of tooth 14 in a car accident. She was

a non-smoker, in good general health and required

restoration of function and esthetics in the central

maxillary tooth region.

Initial examination

The remaining dentition was in good condition. The

patient had a good oral hygiene standard and exhib-

ited no open carious lesions or periodontitis. The clini-

cal examination and the radiographs demonstrated

the

presence of an edentulous ridge with advanced

bone

loss at sites 11,12 and 13. Tooth 14 presented with

horizontal root fracture at the middle of the root (Fig.

39-

29a,b).

Treatment planning

The patient was informed about the steps included in

ridge augmentation and implant therapy. Particular

attention was paid to explaining the risks, the failure

rate and the possible outcome of a suboptimal esthetic

result.

Due to the small amount of residual bone a two-

stage approach for bone regeneration and implant

placement was considered.

Treatment

Initial treatment

A Maryland bridge was placed as a provisional resto-

ration.

Horizontal and vertical ridge augmentation

Following the placement of crestal and releasing inci-

sions, buccal and palatal mucoperiosteal flaps

were

raised. The flaps extended one tooth mesial and two

teeth distal of the defect.

The bone defect was exposed and debrided with a

chisel. The cortical bone was perforated to expose the

cancellous bone and to stimulate bleeding. A 20 mm

long titanium screw was positioned in the recipient

site, projecting from the defect (Fig. 39-30) and was

intended to support the titanium reinforced e-PTFE

membrane that was subsequently placed and an-

chored to the palatal bone. The defect was filled with

autogenous bone chips harvested from the chin, and

the membrane was anchored to the buccal bone wall

of the defect area (Figs. 39-31a,b,c). The periosteum

was released and the flaps were closed with horizontal

mattress and interrupted sutures. After one month of

healing the fractured tooth in site 14 was extracted.

Implant placement

After 6 months of healing, full thickness flaps were

elevated and the membrane was removed. Three 13

908 • CHAPTER 39

Fig. 39-31. (a) The bone defect was filled with autogenous bone chips harvested from the chin. (b) A titanium rein-

forced e-PTFE membrane was anchored buccally and palatally with the use of titanium pins. (c) Periapical radio-

graph demonstrating the bone fill immediately after the surgery.

Fig. 39-32. After 6 months of healing flaps were ele-

Fig. 39-33. A connective tissue graft harvested from the

vated and the membrane removed. Three implants, 13palatal mucosa was positioned on top of the bone crest

mm long, were placed in sites 11, 13 and 14.

to augment the thickness of the soft tissue.

Fig. 39-34. After the abutment connection was per-

Fig. 39-35. Full ceramic abutments were inserted to sup-

formed, the patient used a provisional acrylic bridge

port a (porcelain fused to metal) four-unit bridge.

for six months.

PROCEDURES USED TO AUGMENT THE DEFICIENT ALVEOLAR RIDGE •

909

mm long implants were placed in sites 11, 13 and 14

(

Fig. 39-32). Before the wound was closed, a connec-

tive tissue graft, harvested from the palatal mucosa,

was positioned on top of the bone crest to augment the

thickness of the mucosa (Fig. 39-33).

Restorative therapy

Abutment connection was performed after 4 months.

The patient used a provisional acrylic bridge for 6

months (Fig. 39-34). During this interval the emer-

gence profiles of the temporary crowns were adjusted

to the correct shape of the soft tissue margin. For the

final restoration full ceramic abutments were used to

support a four-unit bridge (Fig. 39-35).

Fig. 39-36. A 36-year-old woman presenting with a frac

tured mandible. She had lost all the lower incisors and

the buccal alveolar bone plate.

Fig. 39-37. (a) A full thickness remote flap was elevated. (b) Three 15 mm long implants, were placed in position 31,

and 42, 6-8 mm of the implants project outside the bone surface. (c) A titanium reinforced e-PTFE membrane was

adjusted to the defect. The space under the membrane was filled with autogenous bone chips collected from the

chin. (d) The membrane was anchored buccally with four titanium pins.

Patient 4 - Vertical ridge augmentation in the

anterior area of the mandible

This 36-year-old woman had been involved in a car

accident. She presented with a fractured mandible

and,

in addition, she had lost all the lower incisors

together

with the buccal alveolar bone plate in the mandibular

front tooth region. The fracture was

treated with

osteosynthesis and healed uneventfully.

The patient was a non-smoker and was in good

general health. She asked for a fixed restoration in the

lower front tooth region.

Initial examination

The remaining dentition appeared to be in reasonably

good condition. There were no signs of additional

tooth

fracture or soft tissue damage. The patient's oral

hygiene status was below optimal standard. Thus,

large amounts of supragingival plaque were observed

in most segments of the dentition. The clinical and

radiographic examination revealed the presence of a

910 •

CHAPTER

Fig. 39-38. (a) After 6 months the tissues adjacent to the membrane exhibited no signs of inflammation. (b) After

membrane removal, it was possible to assess the complete coverage of the implants with newly formed bone.

Fig. 39-39. After one further month of healing, the abut

ments were inserted.

Fig. 39-40. The final prosthetic rehabilitation was made

with porcelain-fused-to-metal crowns.

deep and wide ridge defect in the frontal region of the

mandible. The defect was covered with a non-kerati-

nized mucosa (Fig. 39-36).

Treatment planning and treatment

An implant-supported restoration was chosen as the

optimal treatment alternative. The adjacent teeth,

therefore, were not to be included in the final restora-

tion. It was further decided that a vertical ridge aug-

mentation procedure had to be performed to improve

the height of the ridge and to allow for proper implant

installation and prosthetic rehabilitation.

Implant placement and vertical ridge augmentation

After the elevation of a full thickness flap (Fig. 39-37a),

three 15 mm long implants were placed in the defect

and in positions 31, 41 and 42. The implant shoulders

were positioned 3 mm apical of the cemento-enamel

junction of the adjacent teeth; 6-8 mm of the "coronal"

portions of the implants were not invested in bone but

projected into the defect space (Fig. 39-37b). A tita-

nium reinforced e-PTFE membrane was adjusted and

anchored to the lingual wall of the defect. The im-

plants supported the membrane and prevented it

from collapsing into the defect. The space under the

membrane was filled with autogenous bone chips

collected from the chin in the same surgical site (Fig.

39-37c). The membrane was fixed buccally with four

titanium pins (Fig. 39-37d). Releasing incisions were

placed in the periosteum at the base of the buccal and

lingual flaps,. The wound was closed with horizontal

mattress and interrupted sutures.

Membrane removal and restorative therapy

The membrane was removed after six months (Fig.

39-38a,b). After one further month, healing abutments

were inserted in a second-stage surgery, and a free

gingival graft, collected from the palatal mucosa, was

placed outside the buccal aspects of the abutments

(

Fig. 39-39). The final prosthetic reconstruction in-

cluded porcelain-fused-to-metal crowns (Fig. 39-40).

Concluding remarks

This case showed how a large defect in the ridge can

be augmented using a one-step technique that in-

volved (1) implant placement, (2) the use of auto-

genous bone graft, and (3) the use of a membrane to

protect the graft.

PROCEDURES USED TO AUGMENT THE DEFICIENT ALVEOLAR RIDGE • 911

Fig. 39-41. (a) A 62-year-old woman exhibiting advanced crestal bone atrophy in the posterior regions of the

mandi

ble. (b) Orthopantomogram demonstrating the bilateral bone atrophy. The inferior alveolar nerves were

located

about 4 mm apical of the bone crest.

Fig. 39-42. A mucoperiosteal flap was elevated both buccally and lingually. Two 10 mm long mini-screws of

tita

nium were placed in the bone, projecting from the bone crest by about 7 mm.

Patient 5 - Vertical ridge augmentation to

allow implant placement in the posterior

segments of the mandible

A 62-year-old woman had been wearing a removable

partial denture in the lower jaw for about 15 years, and

expressed the desire to replace this denture with a

fixed bridge. She was in good general health and was

non-smoker.

Initial examination

The clinical examination revealed that the patient's

oral hygiene was poor. Thus, large amounts of suprag-

ingivally located accumulations of plaque and calcu

lus

were seen in all segments of the remaining denti

tion.

There were also signs of a generalized gingivitis,

but the

probing pocket depth measurements revealed

that

there were no pathologically deepened pockets.

The crown and bridge restorations that were pre-

sent in the posterior segments of the maxilla were of

acceptable quality. The following teeth were missing

the mandible: 35, 36, 37, 38 and 45, 46, 47, 48. Teeth

33, 34 and 43, 44 presented with proper root fillings,

posts and cores.

In the orthopantomogram, it was observed that the

edentulous areas of the mandible exhibited advanced

crestal bone resorption (Fig. 39-41a,b). Further, the

inferior alveolar nerve was located about 4 mm apical

of the bone crest.

Treatment planning

The natural dentition and the crown and bridge resto-

rations in the maxilla were maintainable. A cause-re-

lated periodontal therapy was required. This should

include oral hygiene instruction as well as scaling and

root planing. Implant-supported fixed bridge recon-

struction in the posterior mandible would require

vertical ridge augmentation prior to implant installa-

tion.

The patient was informed about the risks involved

in this treatment and alternative treatment options.

Treatment

Initial therapy

The cause-related periodontal therapy was performed

in order to achieve periodontal health before the in-

itiation of the ridge augmentation procedure.

Vertical ridge augmentation

In both sides of the posterior mandible a crestal inci-

sion was made in the keratinized mucosa of the ridge.

The crestal incision was extended along the natural

teeth. Two vertical releasing incisions were made at

912 • CHAPTER 39

Fig. 39-43. (a) A particulate autogenous bone graft, collected from the chin, was placed on top of the crest. (b,c) The

membrane was stabilized buccally and lingually with the use of mini-screws. (d) Ortopanthomogram demonstrat

ing the bilateral vertical ridge augmentation immediately after the surgery.

Fig. 39-44. After 6 months of uneventful healing the membrane was removed. Note the amount of new bone forma

tion.

the mesial and distal ends of the crestal incision. Buc-

cal and lingual mucoperiosteal flaps were elevated.

The

lingual flap was gently reflected beyond the mylohyoid

insertion of the omohyoid muscle. This was

done in

order to enhance the movability of the flap and

manage a subsequent coronal advancement of the

lingual flap.

Two mini-screws made of titanium and 10 mm long

were placed in the remaining bone. The screws pro-

jected from the bone crest by about 7 mm (Fig. 39-42).

A titanium reinforced e-PTFE membrane was retained

to the lingual bone wall with fixation screws. A par-

ticulated autogenous bone graft, collected from the

chin, was placed on top of the crest and the membrane

was stabilized to the buccal bone wall pins (Fig. 39-

43a,b,c). Care was taken not to sever the alveolar nerve

in particular at the region of the mental foramen. A

releasing incision was placed in the buccal pe-

riosteum. The buccal and lingual flaps were closed

with horizontal mattress and interrupted sutures.

Membrane removal and implant placement

After 6 months of healing, incisions were made, flaps

were elevated, the membranes, pins and mini-screws

were removed, and the amount of new bone that had

formed was assessed (Fig. 39-44). Four implants (10

mm long) were placed in sites 35, 36 and 45, 46 (Fig.

39-45). The sites were left to heal for 6 months.

PROCEDURES USED TO AUGMENT THE DEFICIENT ALVEOLAR RIDGE • 913

Fig. 39-45. Four implants, 10 mm long, were placed in sites 35, 36 and 45, 46 according to the standard surgical tech

nique.

Fig. 39-46. Porcelain-fused-to-metal crowns were inserted. The implant-supported crowns were left without fixed

contact with the natural teeth.

Fig. 39-47. Periapical radiographs demonstrating the implants in the regenerated bone after 3 years of function.

Restorative therapy

After abutment connection, provisional crowns were

placed and left in function for a period of 3 months.

Finally, porcelain-fused-to-metal crowns were in

serted.

The implant supported crowns were not con

nected to

the natural teeth (Fig. 39-46, 39-47).

Concluding remarks

This case illustrates how vertical ridge augmentation

including a GBR technique can be used to restore a

partially edentulous ridge and how implant installation

and crown restoration can be performed subsequently

in the augmented region.

914 • CHAPTER 39

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Localized ridge augmentation using guided bone regenera

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International Journal

Periodontics and Restorative Dentistry 13,

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Localized ridge augmentation using guided bone regenera

tion.

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1998). Vertical ridge augmentation around dental implants

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CHAPTER

Implant Placement in the

Esthetic Zone

URS BELSER, JEAN-PIERRE BERNARD AND DANIEL BUSER

Basic concepts

General esthetic principles and related guidelines

Esthetic considerations related to maxillary

anterior implant restorations

Anterior single-tooth replacement

Sites

without significant tissue deficiencies

Sites

with localized horizontal deficiencies

Sites

with extended horizontal deficiencies

Sites

with major vertical tissue loss

Multiple-unit anterior fixed implant

restorations

Sites without significant tissue deficiencies

Sites with extended horizontal deficiencies

Sites with major vertical tissue loss

Conclusions and perspectives

Scalloped implant design

Segmented fixed implant restorations in the

edentulous maxilla

BASIC CONCEPTS

The clinical replacement of lost natural teeth by

osseointegrated implants has represented one of the

most significant advances in restorative dentistry. Nu

merous studies on various clinical indications have

documented high implant survival and success rates

with respect to specific application criteria (Ekfeldt et

al. 1994, Laney et al. 1994, Andersson et al. 1995,

Branemark et al. 1995, Lewis 1995, Jemt et al. 1996,

Lindqvist et al. 1996, Buser et al. 1997, Ellegaard et al.

1997a,b, Levine et al. 1997, Andersson et al. 1998,

Bryant & Zarb 1998, Eckert & Wollan 1998, Ellen 1998,

Lindh et al. 1998, Mericske-Stern 1998, ten Brug-

genkate et al. 1998, Wyatt & Zarb 1998, Gunne et al.

1999, Lekholm et al. 1999, Van Steenberghe et al. 1999,

Wismeijer et al. 1999, Behneke et al. 2000, Hosny et al.

2000, Hultin et al. 2000, Weber et al. 2000, Boioli et al.

2001, Gomez-Roman et al. 2001, Kiener et al. 2001,

Mengel et al. 2001, Oetterli et al. 2001, Zitzmann et al.

2001, Bernard & Belser 2002, Buser et al. 2002, Haas et

al. 2002, Leonhardt et al. 2002, Romeo et al. 2002).

Several recently published studies have focused on

treatment outcome of implant therapy in partially

edentulous patients in general, and related to maxil-

lary anterior implant restorations in particular. Belser

(

1999) reviewed selected publications which appear to

have impact when it comes to the discussion of es-

thetic aspects which will be addressed in this chapter.

In a prospective longitudinal study involving a total of

94 implants (50 in the anterior maxilla) restored with

fixed partial dentures (FPDs), Zarb and Schmitt (

1993) published an average success rate of 91.5% for

an observation period up to 8 years. The respective

data concerning the maxillary implants demonstrated

success rate of 94% (100% for the prosthesis success).

It was concluded that implant therapy in anterior

partial edentulism can replicate the data established

in the literature for fully edentulous patients. The

same authors (Schmitt & Zarb 1993) published an

year implant survival rate of 97.9% for single-tooth

replacement in partially edentulous patients. These

results were confirmed by Avivi-Arber and Zarb in

1996.

Andersson et al. (1998) published similarly favor-

able prospective 5-year data on single-tooth restora-

tions, performed either in a specialist clinic or in gen-

eral practices, while Eckert and Wollan (1998) pre-

sented a retrospective evaluation up to 11 years on a

total of 1170 implants inserted in partially edentulous

patients, and found no differences in survival rates

with respect to the anatomical location of the im-

plants. A meta-analysis concerning implants placed

for the treatment of partial edentulism was carried out

by Lindh et al. (1998). The 6–7-year survival rate for

single implant crowns corresponded to 97.5%, while

the survival rate of implant-supported fixed partial

916 • CHAPTER 40

Fig. 40-1. The esthetic checklist, describing a number of

respective fundamental objective criteria as they relate

to the maxillary anterior segment (detailed description

presented in Table 40.1). (Reprinted from Magne & Bel

ser 2002, with permission.)

Table 40.1. Fundamental objective esthetic criteria

(Magne & Belser 2002)

Gingival health

Interdental closure

Tooth axis

Zenith of the gingival contour

Balance of the gingival levels

Level of the interdental contact

Relative tooth dimensions

Basic features of tooth form

Tooth characterization

10.

Surface texture

11.

Color

12.

Incisal edge configuration

13.

Lower lip line

14.

Smile symmetry

Subjective criteria (esthetic integration)

Variations in tooth form

Tooth arrangement and positioning

Relative crown length

Negative space

dentures (FPDs) was 93.6%. The influence of implant

design and surface texture was investigated by Nor-

ton

(1998) by means of a radiographic follow-up of 33

implants loaded for up to 4 years. A most favorable

maintenance of marginal bone around the conical col-

lar was revealed, with a mean marginal bone loss of 0.

32 mm mesially and 0.34 mm distally for the whole

group.

Soft tissue stability around implant restorations and

adjacent teeth is of paramount importance within

the

appearance zone (Bengazi et al. 1996, Chang et al.

1999, Ericsson et al. 2000, Grunder 2000, Choquet et al.

2001, Cooper et al. 2001, Mericske-Stern et al. 2001,

Bernard & Belser 2002, Engquist et al. 2002, Haas et

al.

2002, Krenmair et al. 2002). Scheller et al. (1998) spe-

cifically addressed this parameter in their 5-year pro-

spective multicenter study on 99 implant-supported

single-crown restorations. The authors reported over-

all cumulative success rates of 95.9% for implants and

91.1% for implant crowns. Soft tissue levels around

implant restorations and adjacent teeth remained sta-

ble over the entire evaluation period. Wyatt and Zarb

(

1998) published a longitudinal study on 77 partially

edentulous patients, involving a total of 230 implants

and 97 fixed partial dentures, with an observation

period of up to 12 years (mean 5.41 years) after load-

ing. The average implant success rate was 94%, while

the continuous stability of the prostheses (fixed partial

dentures) corresponded to 97%. This study comprised

70 anterior and 31 posterior maxillary implants. No

significant differences with respect to longevity could

detected either between anterior and posterior lo-

cations or between maxillary and mandibular implant

restorations.

Along with osseointegration and restoration of

function, the patient's subjective satisfaction is a key

element of the success of implant therapy. Especially

when the implant is located in the anterior part of the

oral cavity, an essential part of the therapy aims at

creating appropriate conditions, so that finally the

implant prosthesis cannot be distinguished from the

adjacent natural teeth. In this context, a variety of

specific procedures have been developed, including

novel bone augmentation protocols, connective tissue

grafting and reconstruction of lost papillary tissue

(

Bahat et al. 1993, Salama & Salama 1993, Bahat &

Daftary 1995, Salama et al. 1995, Price & Price 1999,

Choquet et al. 2001).

Being part of a comprehensive textbook about clini-

cal periodontology, this chapter will focus primarily

fixed implant restorations located in the esthetic

zone.

General esthetic principles and related

guidelines

The basic parameters related to dental and gingival

esthetics in general and to the maxillary anterior seg-

ment in particular are well established in the dental

literature (Goldstein 1976, Belser 1982, Scharer et al.

1982, Seibert & Lindhe 1989, Goodacre 1990, R(ifen-

acht 1990, Nathanson 1991, Magne et al. 1993a,b,

Chiche & Pinault 1994, Magne et al. 1994, Kois 1996,

Kokich 1996, Magne et al. 1996, Kokich & Spear 1997,

Jensen et al. 1999) and have been recently summarized

in the form of an updated integral check-list by Magne

& Belser (2002). When it comes to the characteristics

of the natural maxillary anterior dentition, a number

of fundamental objective criteria, including gingival

health and its normal morphology as well as dimen-

sion, form, specific structural composition, color, opal-

escence, translucency, transparency and surface tex-

ture of incisors and canines, have been identified (Ta-