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3 Soft Tissue Deficits with Dental Implants

3 Soft Tissue Deficits with Dental Implants

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98



P. R. Klokkevold



Fig. 5.3  Gingival recession on labial surface of single tooth implant replacing the right central

incisor (#8). A wide diameter implant was placed immediately at the time of extraction with intact

socket walls, including the buccal plate of the bone. It was restored about 5  months later after

integration. Gingival margins were relatively even at delivery of final restoration and remained

stable for some time but subsequently receded over the next 18–24 months due to buccal plate

remodeling



Fig. 5.4  The papilla between adjacent implants #7 and #8 is noticeably deficient as compared to

the contralateral papilla between natural teeth #9 and #10. The soft tissue between two implants is

primarily supported by the alveolar crest of the bone. There are no inserting connective tissue

fibers (around implants) to aid in the supracrestal support of soft tissues (Restorative treatment by

Dr. John Beumer, UCLA)



Proper implant position is critical to achieving and maintaining optimal soft tissue aesthetics. In general, implants placed in the anterior maxilla should be positioned slightly (~2 mm) palatal to the center of the original (ideal) tooth position.

This compensates for the existing or anticipated horizontal alveolar bone remodeling/resorption of the buccal plate and facilitates the maintenance of the bone on the

labial surface of the implant. Unless the buccal-lingual alveolar ridge dimension is

substantial, the use of wide diameter implants should be avoided in the anterior

maxilla for the same reason (i.e., preservation and maintenance of buccal bone).



5  Soft Tissue Management for Implants in the Aesthetic Zone



99



Standard, or sometimes narrow, diameter implants should be placed in the center

(mesial-distal) of the tooth position and approximately 3–4 mm apical to the desired

gingival margin to allow proper emergence of the restoration from the tissue. Again,

this assumes there is an adequate volume and location of the bone to support the

implant or there is a plan to reconstruct it. Perhaps the most critical aspect of implant

position relative to soft tissue management is the labial inclination. The position and

angulation of existing maxillary anterior alveolar bone will often require that

implants are placed with a labial inclination and a long axis that projects through the

facial aspect of a planned restoration. Fortunately, there is a moderately wide range

of labial-palatal angulations that can be managed prosthetically with angled or custom abutments, from a vertical direction that emerges through the cingulum to a

facial direction that emerges through the cervical area of the labial aspect. However,

if the long axis of the implant emerges through or apical to the desired gingival

margin, there will almost certainly be excessive soft tissue recession resulting in a

long clinical crown, regardless of prosthetic maneuvering with angled abutments

and customization. Placing implants with a facial inclination that projects apical to

the desired gingival margin must be avoided.

The other important soft tissue management principle is preservation of the interproximal papilla. It is well known that loss of bone and periodontal attachment leads

to gingival recession and loss of interdental papilla height. It has also been well

established that surgical manipulation of soft tissues, especially the interdental

papilla, will result in retraction and loss of soft tissue height—aka “black triangles”

in the proximal space. The presence of periodontitis with attachment loss and bone

loss makes this latter concern much more likely and significant. For this reason,

surgical treatment of periodontal disease is avoided in the anterior maxilla; nonsurgical therapy is preferred over surgical therapy to prevent or minimize loss of interdental soft tissue height. Even in the absence of periodontitis, surgical flap reflection

of papillae can result in black triangles. Surgical manipulation of interproximal soft

tissues should be minimized or avoided.



5.4



Periodontal Anatomy



Soft tissue contours in the natural dentition are supported coronal to the alveolar

bone crest by the normal periodontal attachment apparatus. The supracrestal periodontal anatomy consists of the gingival sulcus, the long junctional epithelial

attachment, and the connective tissue attachment. The outer oral surface of the gingiva consists of several layers of keratinized squamous epithelium extending from

the mucogingival junction up to the free gingival margin. In periodontal health, the

gingival sulcus is lined with just a few cell layers of nonkeratinized squamous epithelium. Apical to the gingival sulcus, a thin, single layer of epithelium forms an

intimately adapted, relatively weak “adhesion” attachment, via hemi-desmosomes,

to the crown and/or root surface. Apical to the long junctional epithelial attachment,

the tissue is firmly attached to the tooth with perpendicular connective tissue

(Sharpey’s) fibers that insert into the cementum. As part of the normal periodontal

attachment apparatus, a multidirectional network of dense collagen fibers intertwine



100



P. R. Klokkevold



and connect soft tissues to the teeth and bone. This periodontal attachment stabilizes

teeth and creates a soft tissue matrix that is relatively immobile. Teeth are non-­

shedding, mineralized tissues that emerge into the oral cavity through the periodontium. The periodontal attachment apparatus is a unique structure in the body that is

responsible for creating and maintaining a seal or barrier around the teeth, which are

constantly exposed to the oral microbial flora. Healthy, non-inflamed periodontal

tissues are resistant to gentle periodontal probe penetration and tissue retraction

away from teeth. When periodontal health is maintained, long-term soft tissue

attachment and stability are predictable.

The biologic dimensions of the periodontal attachment apparatus and gingival

sulcus have been described histologically by Gargiulo and co-workers [1]. While

there is a range of biologic width dimensions around teeth that vary from one individual to another, from one tooth to another, and from one tooth surface to another,

the average dimension of the facial soft tissues is estimated to be about 3 mm, and

the average interproximal “papilla” dimension has been shown to be about 4.5 mm

[1–3]. The critical “papilla” height dimension, measured from the interproximal

crest of the bone to the contact point between crowns of natural teeth, is approximately 5 mm [4]. Interproximal vertical dimensions >5 mm (bone crest to contact)

are less likely to be completely filled by papilla in the natural dentition. An important distinction of the healthy periodontal attachment apparatus, as compared to the

peri-implant soft tissues, is that teeth have a supracrestal zone (~1 mm) of connective tissue attachment with inserting fibers that provides a structural scaffold to support periodontal tissues coronal to the level of the bone, even when alveolar bone is

very thin or missing. For example, it is common in the anterior maxilla to have a

stable, intact periodontal connective tissue attachment without periodontal probing

pocket depth over a root surface with a bony dehiscence. An inserting connective

tissue attachment zone does not exist around implants. Consequently, the only

“seal” around implants is achieved by the relatively weak adhesion of long junctional epithelium. The thickness and density of circumferential collagen fibers in the

surrounding soft tissues can help to stabilize the peri-implant seal, but there are no

inserting fibers. Unsupported tissues that surround implants, especially thin mucosa,

will easily retract away from the implant/restoration.



5.5



Factors that Influence Soft Tissue Aesthetics



Periodontal soft tissue aesthetics are influenced by many factors including tooth

shape, tooth position, proximity of adjacent teeth, periodontal biotype, supporting

bone, and periodontal health. All of these factors will also influence peri-implant

soft tissue aesthetics. The primary difference being that implants do not have inserting connective tissue fibers and therefore rely almost entirely on the bone and adjacent teeth to provide structural support for soft tissues. Additionally, the implant

diameter is typically narrower than the tooth it is replacing. Consequently, periimplant tissues must be full and maintain greater volume in order to have a similar

appearance as the natural periodontium.



5  Soft Tissue Management for Implants in the Aesthetic Zone



101



Triangular



Ovoid



Square



Thin - High Scallop



Average - Medium Scallop



Thick - Flat Scallop



Fig. 5.5 (a) Triangular-shaped teeth typically present with highly scalloped gingiva and tall interproximal papilla height. (b) Ovoid-shaped teeth will present with an average gingival scallop and

an average interproximal papilla height. (c) Square-shaped teeth tend to present with a shallow

gingival scallop and short interproximal papilla height



5.5.1 Tooth Shape, Position, and Proximity

Tooth shape influences the interproximal space and the resultant interdental papilla

height. The overall gingival architecture varies from relatively flat, short papillae

between square-shaped teeth to highly scalloped, tall papillae between triangular-­

shaped teeth (Fig. 5.5). Tall, thin papillae are particularly vulnerable to loss when

manipulated and/or when teeth are lost.

Tooth position influences the soft tissue contours. Gingival margins of teeth that

are prominent (labial) in the arch will tend to be thinner, positioned more apical,

and will be more susceptible to recession. Similarly, gingival margins in patient

with a thin biotype will tend to be more susceptible to recession, whereas teeth that

are more palatal in position will tend to have thicker labial tissue, and the gingival

margins will be less susceptible to recession. Likewise, gingival margins in a

patient with a thick biotype will be more resistant to recession of the gingival

margin.

The normal approximation and contact between adjacent maxillary anterior

teeth form a pyramidal-shaped space that is occupied by interdental papilla. The

base of the pyramid is supported by the interproximal crestal bone and bordered

by the cervical contours of adjacent teeth with the papilla peak rising coronal up

to the contact point. Again, the interproximal tissues, adjacent to teeth, are supported coronal to the bone crest by connective tissue fibers inserting into the

cementum on the root surfaces. If adjacent teeth are crowded, in close approximation or possibly overlapping one another, the interproximal space may be diminished or absent causing the papilla to be blocked out. Conversely, when adjacent

teeth are separated by >2.4 mm, the papilla will be less likely to fill the interproximal space [5]. In a study evaluating the effect of interproximal distance on papilla

presence, the authors reported that the interproximal papilla was always deficient

when the interproximal distance between roots was >4.0 mm [6]. When there is a

diastema, the interproximal soft tissues will be flat (Fig. 5.6). This phenomenon



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