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3 Fine-Tuning Soft Tissue Position Through Alterations to the Emergence Profile

3 Fine-Tuning Soft Tissue Position Through Alterations to the Emergence Profile

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11  Emergence Profile of the Implant Abutment and Its Effects



241



Fig. 11.5  Here a provisional three-unit FDP on two

implants has been used to

shape the peri-­implant

tissues and pontic site. It

was left in place for at least

6 weeks (Surgery by Dr.

Joan Pi-Anfruns)



a



b



Fig. 11.6 (a) Overcontouring the facial area of the emergence will push the tissues apically. This

can be useful to elongate the appearance of a tooth. However, this emergence profile should be

avoided in the initial healing stages. (b) In the immediate implant placement and provisionalization, the facial surface should be significantly undercountoured to allow for swelling, blood supply,

and apical migration of the peri-implant tissues. This will generally provide for an excess of tissue,

which is advantageous around implants



Overcontouring is useful in two applications: to move and shape the gingival

zenith apically to match the contralateral positions and to close gingival embrasure

spaces. Around implants in the aesthetic zone, one of the most difficult challenges

continues to be deficient papilla. It is not uncommon to hear of the papilla being like

a “water balloon” that if compressed at its base will force the tip of it to move coronally. There are a few issues with this idea for our current discussion. This concept

comes from manipulation of papilla between natural teeth. As explained early in

this chapter, there is no cementum for the soft tissues to insert into to support a



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T. R. Schoenbaum and S. Alawie



a



b



c



d



Fig. 11.7 (a) This patient has had an implant and provisional restoration placed on the upper left

canine. Notice the coronal positioning of the gingival zenith due to the undercountoured emergence profile on the provisional. (b) Here the definitive restoration is being tried in. Note that it has

been purposefully designed with an overcontoured surface on the facial to push the tissues apically

and extend the visual length of the canine. The blanching occurs during the initial tightening of the

restoration and should subside over the course of the appointment. No anesthesia is required for

this procedure, but care must be taken to progress slowly. (c) On the left, we can see the undercontoured facial emergence of the provisional designed to increase tissue volumes. On the right, we

can see the overcontoured facial design of the definitive restoration, used to push tissue apically.

(d) After being in position for 15 min, the overcontoured definitive restoration was removed for

additional staining. The provisional was put back into position. Note the significant amount of tissue movement from the change in contour



11  Emergence Profile of the Implant Abutment and Its Effects



243



Fig. 11.8  When fabricating the emergence of the provisional restoration, the gingival embrasures

should be left open to allow for the papilla to migrate coronally. Every patient does not have the

same papilla length, and we must allow for their unique papillary phenotype to reveal itself. If the

embrasure is closed off prematurely, the length of the papilla will be stunted



higher position, only more titanium or zirconia. There is no long epithelial attachment on these materials, as there is on clean cementum. The compression of the

papilla adjacent to an implant may provide increased length in the very short term

(i.e., postop photos), but the increased pressure and contours are more likely to

result in decreased blood supply (blanching) and recession over the long term.

Again, a large part of where the papilla are or will be is dependent on factors outside

the realm of the prosthesis. Dr. Joe Kan has described much of the science behind

the peri-implant papilla in Chap. 9.

In the author’s opinion, peri-implant papilla are best managed by allowing space

in the gingival embrasure during the period following implant placement and provisionalization (Fig.  11.8). This allows time for the papilla to mature and migrate

coronally to the greatest extent possible given the patient genetics and the hard and

soft tissue foundation. The ultimate length of the papilla is not universal but could

be represented by a bell curve (Fig.  11.9). Some patients will have papilla that

migrate quite far, perhaps up to 7 mm from the crest of the bone, while others will

have papilla no longer than 2 or 3 mm [23, 24]. The open gingival embrasure of the

provisional restoration allows the clinician to see which part of the bell curve this

particular patient falls on. The undercontoured emergence profile maximizes the

amount of room for blood supply and postoperative swelling without traumatizing

the tissues.

Following osseointegration and maturation of the gingiva, the soft tissue positions are evaluated. This should be performed at 12–16 weeks after placement of

the implant and provisional restoration. If the papilla failed to fully fill the gingival

embrasure, the remaining space (if desired) can be filled by the definitive prosthesis and perhaps a small restoration on the adjacent teeth. At this point, the position

of the gingival margin and zenith are evaluated. If modification is desired, the

provisional is removed and composite resin added to the areas where apical movement of the gingiva is desired. This procedure is adapted from the similar procedure used with traditional gingivectomies, to hold the tissues back while they

mature. The number of times the provisional restoration is removed and modified

should be limited. Repeated removal of components at the implant level has been



244



T. R. Schoenbaum and S. Alawie



95%



Frequency



68%



–2σ



–1σ



0



3mm











10mm

Papilla height



Fig. 11.9  Like most physiologic measurements, the length of the papilla falls along a typical bell

curve. Some patients have very short papilla, no matter the surgeon, materials, emergence profiles,

etc. Some patients may have papilla of 7 or more millimeters in length. Most evidence has shown

that papilla between natural teeth are at least a 5 mm, while those around reasonably placed single

implants average about 4 mm



shown to result in additional loss of bone and soft tissue, the exact opposite effect

of what we are trying to accomplish. As such, removal and modification should not

be performed in the first 3 months following implant placement, and it should be

done at most once.

After the provisional restoration is modified and replaced, it should remain in

place, undisturbed for 6 weeks. This allows sufficient time for the peri-implant soft

tissue “O-ring” to develop and mature. It will continue to do so even after 6 weeks,

but most of the change has occurred by then. At the 6-week reevaluation, final photos and impressions are made. The use of a custom impression coping (as described

by Dr. Papaspyridakos in Chap. 10) should be used to ensure that the laboratory

technician has an exact replica of the soft tissue in the patient’s mouth.



11.4 Summary

Understanding the physiological effects of the emergence zone allows the clinician

to carefully tune the definitive positions of the peri-implant soft tissues. The emergence profile of the abutment can be overcontoured to move tissue apically or

undercontoured to allow tissue to move coronally. As described in this chapter, the

clinician must carefully employ these concepts at the right time to achieve the best

possible results. It should also be clearly understood that this technique is for “finetuning.” Serious deficiencies of bone or soft tissue must be resolved surgically or

with pink prosthetic materials.



11  Emergence Profile of the Implant Abutment and Its Effects



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References

1. Rowan M, Lee D, Pi-Anfruns J, Shiffler P, Aghaloo T, Moy PK. Mechanical versus biological

stability of immediate and delayed implant placement using resonance frequency analysis. J

Oral Maxillofac Surg. 2015;73(2):253–7.

2.De Rouck T, Collys K, Wyn I, Cosyn J.  Instant provisionalization of immediate single-­

tooth implants is essential to optimize esthetic treatment outcome. Clin Oral Implants Res.

2009;20:566–70.

3.Schoenbaum TR, Chang YY, Klokkevold PR, Snowden JS. Abutment modification for immediate implant provisional restorations. J Esthet Restor Dent. 2013;25:103–7.

4.Schoenbaum TR, Swift EJ. Abutment emergence contours for single-unit implants. J Esthet

Restor Dent. 2015;27(1):1–3.

5. Abrahamsson I, Berglundh T, Lindhe J. The mucosal barrier following abutment dis/reconnection. J Clin Periodontol. 1997;24(8):568–72.

6.Berglundh T, Lindhe J, Ericsson I, Marinello CP, Liljenberg B, Thornsen P. The soft tissue

barrier at implants and teeth. Clin Oral Implants Res. 1991;2(2):81–90.

7.Lindhe J, Berglundh T, Ericsson I, Liljenberg B, Marinello C.  Experimental breakdown of

peri-implant and periodontal tissues. A study in the beagle dog. Clin Oral Implants Res.

1992;3(1):9–16.

8.Piattelli A, Scarano A, Piattelli M, Bertolai R, Panzoni E. Histologic aspects of the bone and

soft tissues surrounding three titanium non-submerged plasma-sprayed implants retrieved at

autopsy: a case report. J Periodontol. 1997;68(7):694–700.

9.Rodríguez X, Navajas A, Vela X, Fortuño A, Jimenez J, Nevins M.  Arrangement of peri-­

implant connective tissue fibers around platform-switching implants with conical abutments

and its relationship to the underlying bone: a human histologic study. Int J Periodontics

Restorative Dent. 2016;36(4):533–40.

10.Rompen E, Raepsaet N, Domken O, Touati B, Dooren EV. Soft tissue stability at the facial

aspect of gingivally converging abutments in the esthetic zone: a pilot clinical study. J Prosthet

Dent. 2007;97:S119–25.

11.Crespi R, Capparè P, Gherlone E.  Radiographic evaluation of marginal bone levels around

platform-switched and non-platform-switched implants used in an immediate loading protocol. Int J Oral Maxillofac Implants. 2009;24(5):920–6.

12.Fickl S, Zuhr O, Stein JM, Hürzeler MB.  Peri-implant bone level around implants with

platform-­switched abutments. Int J Oral Maxillofac Implants. 2010;25(3):577.

13.Hürzeler M, Fickl S, Zuhr O, Wachtel HC.  Peri-implant bone level around implants with

platform-­switched abutments: preliminary data from a prospective study. J Oral Maxillofac

Surg. 2007;65(7):33–9.

14.Lazzara RJ, Porter SS. Platform switching: a new concept in implant dentistry for controlling

postrestorative crestal bone levels. Int J Periodontics Restorative Dent. 2006;26(1):9–17.

15. Pieri F, Aldini NN, Marchetti C, Corinaldesi G. Influence of implant-abutment interface design

on bone and soft tissue levels around immediately placed and restored single-tooth implants: a

randomized controlled clinical trial. Int J Oral Maxillofac Implants. 2011;26(1):169–78.

16.Trammell K, Geurs NC, O’Neal SJ, Liu PR, Haigh SJ, McNeal S, Kenealy JN, Reddy MS. A

prospective, randomized, controlled comparison of platform-switched and matched-abutment implants in short-span partial denture situations. Int J Periodontics Restorative Dent.

2009;29(6):599–605.

17.Canullo L, Penarrocha-Oltra D, Soldini C, Mazzocco F, Penarrocha M, Covani



U.  Microbiological assessment of the implant-abutment interface in different connections: cross-sectional study after 5 years of functional loading. Clin Oral Implants Res.

2015;26(4):426–34.

18.Cássio do Nascimento DM, Paola Kirsten Miani DM, Pedrazzi V, Gonỗalves RB, Ribeiro

RF, Faria AC. Leakage of saliva through the implant-abutment interface: in  vitro evaluation of three different implant connections under unloaded and loaded conditions. Int J Oral

Maxillofac Implants. 2012;27(3):551–60.



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19.Peñarrocha-Diago MA, Flichy-Fernández AJ, Alonso-González R, Parrocha-Oltra D,



Balaguer-Martínez J, Parrocha-Diago M.  Influence of implant neck design and implant–

abutment connection type on peri-implant health. Radiological study. Clin Oral Implants Res.

2013;24(11):1192–200.

20.Linkevicius T, Vindasiute E, Puisys A, Linkeviciene L, Maslova N, Puriene A. The influence

of the cementation margin position on the amount of undetected cement. A prospective clinical

study. Clin Oral Implants Res. 2013;24(1):71–6.

21.Linkevicius T, Vindasiute E, Puisys A, Peciuliene V. The influence of margin location on the

amount of undetected cement excess after delivery of cement-retained implant restorations.

Clin Oral Implants Res. 2011;22(12):1379–84.

22.Lops D, Chiapasco M, Rossi A, Bressan E, Romeo E.  Incidence of inter-proximal papilla

between a tooth and an adjacent immediate implant placed into a fresh extraction socket:

1-year prospective study. Clin Oral Implants Res. 2008;19:1135–40.

23.Tarnow DP, Magner AW, Fletcher P. The effect of the distance from the contact point to the

crest of bone on the presence or absence of the interproximal dental papilla. J Periodontol.

1992;63(12):995–6.

24.Tarnow DP, Elian N, Fletcher P, Froum S, Magner A, Cho SC, Salama M, Salama H, Garber

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adjacent implants. J Periodontol. 2003;74(12):1785–8.



Cemented Implant Restorations

in the Aesthetic Zone: Biological,

Functional, and Aesthetic

Considerations



12



Alireza Moshaverinia and Todd R. Schoenbaum



Abstract



Implant treatment in the aesthetic zone can be a challenging clinical situation,

which requires high level of communication between the surgeon, the technician,

and the restoring dentist. In this chapter, different abutment materials available in

the market will be discussed, and the rationale for their applications, advantages,

and disadvantages will be reviewed. Additionally, screw-retained and cement-­

retained implant-supported restorations will be briefly compared, and related

clinical considerations will be discussed. Furthermore, abutment design parameters and technician factors will be reviewed. Finally, clinical guidelines will be

provided to avoid complications and failures.



12.1 Rationale and Success Rates

Implant treatment in the aesthetic zone requires high levels of collaboration between

the surgeon, the technician, and the restoring dentist. Selection and design of the

definitive restoration/abutment is the final stage of the process. There is often much

discussion about which restoration type (screw or cement retained) is better.

Fortunately, many reviews have been performed on this topic looking at thousands

of crowns from hundreds of dentists. Looking at the data, it becomes quite clear that

either screw-retained or cement-retained single-unit crowns can be done with

A. Moshaverinia (*)

Division of Advanced Prosthodontics, School of Dentistry, University of

California, Los Angeles, Los Angeles, CA, USA

e-mail: amoshaverinia@dentistry.ucla.edu

T. R. Schoenbaum

Division of Constitutive and Regenerative Sciences, University of California,

Los Angeles, CA, USA

© Springer International Publishing AG, part of Springer Nature 2019

Todd R. Schoenbaum (ed.), Implants in the Aesthetic Zone,

https://doi.org/10.1007/978-3-319-72601-4_12



247



248



A. Moshaverinia and T. R. Schoenbaum



equivalent success rates for both biologic and technical standpoints [1–5].

Technician-­related factors (e.g., design), as well as abutment design parameters, set

by the clinician certainly affect outcomes.

There are of course certain protocols that must be followed to minimize the risk

of failure; with cemented restorations, we are particularly concerned about cement-­

induced peri-implantitis (Fig. 12.1) [6–8]. Complications will be discussed at the

end of this chapter.

There are a few scenarios where a cemented restoration will be the superior

choice (as there are also scenarios where a screw-retained option is better). With

ideal implant placement, either option can generally be viable. The most obvious

case in the aesthetic zone is when the implants are angled out through the facial

(Fig.  12.2). This scenario is a relative contraindication to screw-retained restorations due to the screw access location on the incisal edge or on the facial surface.

Some manufacturers have overcome this challenge by designing screws and drivers

that can work up to 25° off axis.

A cemented option is also indicated when adjacent crowns or veneers are being

placed. The rationale is that the technician cannot usually match a screw-retained

PFM or PFZ restoration to the materials used for crowns/veneers in the aesthetic

zone (Fig. 12.3a, b). For single-unit implant treatment in the aesthetic zone, most

technicians can better replicate natural tooth aesthetics with a cemented

restoration.

Fig. 12.1 Peri-implantitis

has multiple possible

etiologies, the most notorious

of which is cement retained

on the subgingival surface of

the abutment. This problem is

primarily caused by abutment

margins that are too deep

subgingivally



12  Cemented Implant Restorations in the Aesthetic Zone



249



Fig. 12.2  For the partially edentulous patient, cemented restorations are particularly useful when

implants have been placed with a facial angulation. There are some esoteric ways around the use

of a cemented crown (i.e., angled screw channels, lingual set screws) in such scenarios, but they

are proprietary or rarely employed. It is inevitable that restoring implants in the aesthetic zone will

require the use of cemented restorations, and it is imperative that the clinician be able to perform

this with a high level of success



a



c



b



d



Fig. 12.3 (a) Cemented restorations are particularly useful for mixed treatment cases. (b) Here a

crown, implant crown and a veneer have all been fabricated out of the same material (layered

lithium disilicate) to ensure aesthetic harmony. Such results would be extremely difficult and

unpredictable with a screw-retained implant PFM restoration. A three-unit-layered zirconia FDP

with custom-milled titanium abutments (c, d). The margins prescribed at −0.5 mm



250



a



A. Moshaverinia and T. R. Schoenbaum



b



Fig. 12.4  Tissue-level implants should primarily be restored with screw-retained restoration. This

implant design is poorly suited to use with cemented restorations or anywhere in the aesthetic

zone. The margins of the crown or prosthesis are dictated by the position of the implant, and as

such the mesial and distal margins are almost always too deep subgingival to properly manage

cement. (a, b) A tissue-level implant demonstrating the challenge of margin position and subsequent peri-implant mucositis resulting from the deep margins at the mesial and distal



But aesthetics is only one of the concerns and means little if biological and

functional risks are too great. To mitigate these concerns, the abutment selection and design are critical. Peri-implantitis has various etiologies, one of

which is cement retained in contact with the bone or tissues. This issue has

been thoroughly explored later in this chapter. Overall, risk of retained cement

decreases significantly when the margins are placed appropriately (i.e., <1 mm

deep) [2, 9, 10].

To achieve the above goal, it is imperative to use an implant system which has

custom-milled abutments as an option (Fig. 12.3c, d). It is virtually impossible to

place the margins in the correct position with stock abutments or with a tissue-level

implant designs (Fig.  12.4a, b). There are reasonable scenarios for tissue-level

implants, but the aesthetic zone is not among them.



12.2 Abutment Material Considerations

Contemporary abutment material options for the partially edentulous patient

include cast gold alloy, titanium (Fig. 12.5a), full-contour zirconia (Fig. 12.5b),

and zirconia with a titanium base (Fig. 12.5c). Other options exist (i.e., lithium

disilicate, chrome cobalt, alumina) but will not be discussed here due to their

limited use. Overall, we will see that zirconia abutments tend to give a better gingival color, though they are more prone to failure under excessive loads [11, 12].

The biocompatibility of the various materials and their effect on the peri-implant

tissues is unclear, as good data exists for both Zr and Ti. For functional strength,

we will see that titanium (or cast gold alloys) are superior but tend to discolor the

tissues more [13]. Zirconia abutments have recently been designed with a titanium base to mitigate many of the issues associated with the full-contour zirconia

abutments.



12  Cemented Implant Restorations in the Aesthetic Zone



a



251



b



c



Fig. 12.5 (a) Custom-milled titanium abutments with margins prescribed at −0.5 mm. (b) Full-­

contour zirconia abutments with margins prescribed at −0.5 mm. Note that when seated, all margins are clearly visible circumferentially. (c) Zirconia abutment mated to a titanium base. This

design is ideal (though not available for all implant manufacturers) because it brings the aesthetics

of zirconia but removes the risk for zirconia breakage inside the implant



When selecting the abutment material, there are three key considerations:

–– Biology (Is one material more biocompatible than the others?)

–– Function (Is the abutment strong enough?)

–– Aesthetics (Will the abutment gray the tissues?)

Titanium is the most biocompatible metal available. The unique property of the

titanium abutments (either commercially pure titanium (CP Ti) or titanium alloy

(Ti-6Al-4 V)) is due to the possibility of the formation of TiO2 protective film on the

surface of titanium. Therefore, it is the oxide layer, which is in contact with the tissue, and not the metal itself. Titanium has a lower density than base metal casting

alloys and possesses much lower density than noble metal casting alloys. In addition, titanium as an abutment material shows desirable mechanical properties. The

other desirable characteristics of Ti abutments are their anticorrosive properties.

Based on the presence of different elements such as iron (Fe) and oxygen (O), titanium can have four grades (I–IV), where grade IV is the strongest one and has the

highest levels of Fe and O. Strengthening of grades I–IV CP titanium is provided by

interstitial impurity atoms (C, H, O, and N), where O is the most important [14, 15].

Titanium alloy (Ti-6Al-4  V) or grade V titanium contains 6% aluminum, 4%

vanadium, 0.25% (maximum) iron, 0.2% (maximum) oxygen, and the remainder



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