Graftless Solutions for the Edentulous Patient

This book, designed to meet the needs of clinicians, clearly explains the rationale and technique for the rehabilitation of fully edentulous patients utilizing traditional graftless concepts as well as zygomatic implant strategies when posterior support cannot be achieved by the former means. Considerations relevant to treatment planning and the biomechanics of immediate loading and zygomatic implants are first discussed. The techniques for placement of traditional tilted and zygomatic implants and for immediate loading of a full arch restoration are then described step by step. Detailed information and guidance are also provided on the different materials available for full arch restorations, laboratory aspects of the definitive restoration, maintenance of restorations, and management of prosthetic and surgical complications. The book concludes with a helpful series of clinical cases. Graftless Solutions for the Edentulous Patient is designed particularly for clinicians with experience in placing and restoring dental implants. 

• Language: English
• Publisher: Springer
• Release date: Feb 21, 2018
• ISBN: 9783319658582

Book preview

© Springer International Publishing AG 2018

Saj Jivraj (ed.)Graftless Solutions for the Edentulous PatientBDJ Clinician’s Guideshttps://doi.org/10.1007/978-3-319-65858-2_1

1. Diagnosis and Treatment Planning: A Restorative Perspective

Saj Jivraj¹, ², ³   and Hooman Zarrinkelk⁴, ⁵, ⁶  

(1)

Herman Ostrow USC School of Dentistry, Los Angeles, CA, USA

(2)

Eastmann Dental Institute, London, UK

(3)

Private Practice, Oxnard, CA, USA

(4)

Diplomate, American Board of Oral and Maxillofacial Surgeons, Chicago, IL, USA

(5)

Fellow, American College of Oral and Maxillofacial Surgeons, Washington, DC, USA

(6)

Private Practice, Ventura, CA, USA

Saj Jivraj (Corresponding author)

Email: [e-mail]

Hooman Zarrinkelk

Email: [e-mail]

Abstract

Treatment of the edentulous patients with implant-supported restorations presents a significant challenge to the treating clinician. Patient expectations in regard to aesthetics, phonetics, form and function are high.

There are a myriad of factors that need to be evaluated to determine if the patient is a suitable candidate for a fixed vs. a removable implant-supported restoration. Evaluation of the edentulous patient is also complicated by the fact that patients may not only be missing clinical crown height but in addition may have experienced a combination of tooth, soft tissue and bone loss, with associated changes in facial form.

The purpose of this chapter is to evaluate the diagnostic factors that are critical in treatment planning of a patient for fixed implant-supported restorations.

The predictability of successful osseointegrated implant rehabilitation of the edentulous jaw as described by Branemark et al. [1] introduced a new era of management for the edentulous predicament.

Implant rehabilitation of the edentulous patient remains one of the most complex restorative challenges because of the number of variables that affect both the aesthetic and functional aspects of the prosthesis.

The routine treatment for edentulism has been complete dentures. Epidemiological data has reported that the adult population in need of 1 or 2 dentures would increase from 35.4 million adults in 2000 to 37.0 million adults in 2020 [2], and the researchers warn that their estimates may be significantly conservative. Clinical studies have reported that patients with dentures have shown only a marginal improvement in the quality of life when compared with implant therapy [3]. The common reasons for dissatisfaction in patients using dentures include but are not limited to pain, poor retention and stability and difficulty eating [4].

A review of the literature noted that prostheses supported by osseointegrated implants significantly improved the life of edentulous patients when compared with conventional dentures [5].

Many patients tolerate complete dentures despite the dissatisfaction.

Reasons for this could be the following:

Anatomic: They have been told that they are not implant candidates because of pneumatized sinuses and severe resorption of the posterior mandible.

Cost.

Lack of education: They have not been educated about dental implants and do not visit a dentist because they feel nothing can be done for them.

Restoration of the edentulous patients with dental implants is costly whichever method is used to restore the patient. Fixed reconstructions require more laboratory assistance and implant parts, and, thus, are a lot more costly.

Due to economic factors, many patients have been provided with implant- and mucosa-supported overdentures.

However, cost needs to be considered not only during fabrication of the prosthesis but also during maintenance. Overdentures seem to have more post-insertion maintenance than their fixed counterparts. If this is consistent, it could be questioned whether an economic indication for choosing an overdenture could be justified when there is sufficient bone to support implants for a fixed prosthesis. The patient must be made aware that maintenance costs for removable prostheses on implants will be higher than those of a fixed prosthesis. Today, clinicians are seeing an increasing number of dentate patients where the dentition is terminal. These patients would have been edentulous a long time ago if it had not been for the efforts of skilled restorative dentists. Clinical treatments have involved maintaining non-restorable teeth for as long as possible to avoid a removable appliance. Patients understand that maintaining a terminal dentition has consequences on the bone. However, the fear of edentulism forces them to ignore failing oral conditions.

In spite of the increasing numbers of edentulous or soon-to-be edentulous patients, there still appear to be many reasons why patients avoid treatment with dental implants.

These reasons could include the following:

The fear of wearing a removable appliance in the transitional phase

The notion that the proposed treatment is time consuming and unpredictable

The number of visits involved and the fear of pain

Cost

Most patients will look toward an implant rehabilitation hoping to acquire a fixed prosthesis. Treatment planning of edentulous patients with fixed restorations on dental implants has undergone a paradigm shift since the introduction of graft-less solutions, in particular the All-on-4 method™.

Today, patients have options whereby in the right indication complete rehabilitation can be accomplished by the use of four implants per arch. The major advantages of this procedure are reduced number of implants and ability to bypass extensive grafting procedures. This rehabilitation not only satisfies aesthetics and function but also considerably reduces costs for the patient. This ultimately results in increased patient acceptance and an increased number of patients treated. Very few patients today are able to afford extensive implant rehabilitations on six to eight implants and the All-on-4™ or graft-less protocol is gaining popularity as being the treatment of choice for the edentulous patient.

In a world environment where the numbers of edentulous patients are increasing, there are not enough available dentists trained in these protocols to be able to treat them. Patients are not given these options because of the dentist’s reluctance to offer them. Reasons for this are lack of education and the notion that these treatment protocols are not predictable despite there being numerous multicentre studies to the contrary.

As in all phases of dentistry, diagnosis is critical in obtaining a predictable outcome. An incomplete or erroneous diagnosis can yield unsatisfactory results for both the patient and treating clinician.

The decision-making parameters when rehabilitating patients require the clinician to make a decision as to whether a fixed or a removable prosthesis would be more suitable. Zitzmann and Marinello [6] and Jivraj et al. [7] described in detail parameters that need to be evaluated. A fixed restoration should not be promised to a patient until all diagnostic criteria are evaluated. These criteria must include quality and quantity of bone available to support implants, lip line, lip support and aesthetic demands. Implants should not be placed until a definitive treatment plan has been established as implant positions may vary depending on the type of prostheses to be delivered.

From a diagnostic perspective, several parameters need to be evaluated before deciding upon the type of prosthesis that is most appropriate for the patient. The following considerations pertain to restorative treatment planning (Fig. 1.1). Surgical considerations will be presented in a separate chapter:

1.

Positioning of the maxillary and mandibular incisal edge

2.

Restorative space

3.

Lip support

4.

Smile line and lip length

5.

Contours and emergence

6.

Tissue contact

7.

Occlusion

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Fig. 1.1

Factors that need consideration before deciding upon a fixed vs. removable implant rehabilitation

1.1 Positioning the Maxillary and the Mandibular Incisal Edge

The maxillary incisal-edge position is determined utilizing the principles of aesthetics and phonetics. Traditional guidelines tell us that when the patient makes the F sound, the incisal edge should touch the vermillion border of the lower lip. Once the incisal-edge position has been established, the length for the central incisors is determined. On average, the length of the central incisors is 10.5 mm; this can be more in elderly patients who exhibit gingival recession [8]. The axial inclination of the central incisor should be placed so as to provide adequate support for the upper lip. Once the crown length, angulation and coronal form have been determined, the distance between the cervical crown margin and residual bone must be established to determine if adequate space exists for the anticipated restoration. Often the maxillary incisal edge is overerupted and treatment planning involves repositioning the incisal edge more apically (Fig. 1.2). Putting the maxillary central in the right position may require alveolectomy to provide sufficient running room from the head of the implant fixture to the emergence profile as it exits the free gingival margin [9].

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Fig. 1.2

Repositioning the incisal edge more apically will have an impact on the implant placement. Alveolectomy will need to be performed prior to implant placement in this patient’s case

To determine if a fixed or removable restoration would be appropriate, a wax try-in is done without a flange. For a fixed restoration, the clinical crown should ideally end up at the soft-tissue level of the alveolar ridge. In this situation, minimal resorption would have occurred, interarch space will be favourable and an optimal tooth-lip relationship is present. When a large vertical distance exists between the cervical aspect of the tooth and the alveolar ridge but the tooth-lip relationship is favourable, pink ceramic or acrylic may be utilized to disguise the tooth length and a fixed restoration is still possible. When there is both a vertical and horizontal discrepancy between the ideal position of the tooth and the alveolar ridge, and the tooth-lip relationship is not optimal, this may be an indication for use of a removable prosthesis. The flange will provide adequate lip support, and the teeth can be positioned appropriately to satisfy the parameters of aesthetics.

The mandibular incisal edge is positioned for function. The clinician must provide shallow guidance, sufficient to provide posterior disclusion in both protrusive and lateral excursions. Anterior guidance must be smooth and distributed amongst as many anterior teeth as possible.

A thorough evaluation must be made of the existing mandibular incisal-edge position . When patients are missing posterior teeth and have been diagnosed as having lack of posterior support the mandibular incisal edge is often in the incorrect position. The clinician must decide whether to reshape, reposition or restore if the maxillary arch is being considered for implant-supported restorations. Conventional prosthodontic guidelines will place the mandibular incisal edge just at the level of the lower lip with 0.5–1.0 mm of the incisal edge visible. Guidelines in relation to the lower mandibular occlusal plane can also be sought from anatomical landmarks such as the retromolar pad.

If the clinician is planning a fixed implant-supported restoration for the mandible, adequate restorative space must be provided. The overeruption of teeth brings with it an excess of bone, which must be reduced prior to the implants being placed.

1.2 Restorative Space

Insufficient restorative space is the most common error when planning full-arch restorations. Inadequate space results in either premature failure of the restoration or changing the treatment plan from one restoration to another to accommodate the space requirements.

To accommodate adequate designs, different types of restorations require different dimensional tolerances [7]. Accurately mounted casts are critical in assessing prosthetic space limitations. Spatial constraints must be considered as a matter of practicality. The limiting factor in edentulous patients is the available inter-arch space.14. Adequate restorative space is critical, and guidelines exist depending upon the type of prosthesis in the treatment being planned. There must be adequate space for bulk of restorative material that also permits a prosthesis design to establish aesthetics and hygiene. If space is limited, re-establishing a patient’s vertical dimension or altering the opposing occlusion should be considered [10].

Guidelines for space requirements for ceramic-based restorations are 10–13 mm for a screw-retained ceramic-based restorations and 14–16 mm for acrylic resin/titanium-based restorations (Figs. 1.3 and 1.4) [6, 7].

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Fig. 1.3

Inadequate restorative space can result in restoration fracture

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Fig. 1.4

Resin-based restorations require 15–18 mm of restorative space

1.3 Lip Support

One of the best diagnostic tools is the patient’s existing maxillary denture. The clinician can evaluate the patient’s denture to determine what are the likes and dislikes regarding aesthetics, speech and function. Each point should be noted for improvements in the new restoration. There is always a tendency for patients to prefer fixed over removable prostheses. It is the restorative dentists’ responsibility to determine if this is feasible. Facial support is an important decision in this regard.

Assessment of the patient’s facial support with and without the denture in place, with the patient facing forward and in profile, needs to be made so the clinician can determine which type of prostheses would be more suitable (Figs. 1.5 and 1.6).

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Fig. 1.5

Looking at the profile view of the patient with the denture in and out can give the clinician an indication if the flange of the denture is required for lip support

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Fig. 1.6

This patient has an obvious lack of lip support with a concave facial profile

Facial support, if inadequate, is obtained mainly by the buccal flange of a removable restoration. Lip support is derived from the alveolar ridge shape and cervical crown contours of the anterior teeth. Resorption of the edentulous maxilla proceeds cranially and medially and this often results in a retruded position of the anterior maxilla.

When evaluating a diagnostic set-up with the anterior teeth in proper relation to the lip, the position of the anterior teeth is often anterior to the alveolar ridge (Figs. 1.7 and 1.8). Depending on the severity of the resorption, there can be a discrepancy between the ideal location of the teeth and the ridge. This, in turn, leads to a discrepancy of the anticipated position of the implants in relation to the teeth. This discrepancy must be taken into consideration to achieve a prosthesis that satisfies the parameters of adequate speech, lip support, hygiene, sufficient tongue space and patient acceptance.

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Fig. 1.7

When requesting a diagnostic denture set-up from a dental technician, a flangeless try-in should be requested

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Fig. 1.8

Patient with flangeless try-in. This patient is a candidate for a fixed implant-supported restoration

If the anticipated position of the teeth and implant results in a large horizontal discrepancy, a number of options must be considered before finalizing implant placement.

If the horizontal discrepancy is quite large, options include the following:

(a)

Bone reduction and a deeper implant placement to allow the contours of the restoration to satisfy the parameters of lip support and hygiene: Without bone reduction, undesirable contours in the restoration are developed, which make it very difficult for the patient to maintain hygiene (Fig. 1.9).

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Fig. 1.9

If a patient with inadequate lip support requests a fixed restoration the clinician must assess to see if this is possible. On occasion bone must be removed and the implant placed higher up so the emergence of the restoration can start higher up

(b)

LeFort I osteotomy: Most patients are reluctant to undergo this type of surgery.

(c)

Use of a removable flange and fabrication of an implant-supported overdenture.

1.4 Smile Line and Lip Length

The movement of the upper lip during speech and smiling should be evaluated. Tjan et al. [8] described the average smile as having the position of the upper lip such that 75–100% of the maxillary incisors and interproximal gingival are displayed. In a high smile line, additional gingival is exposed, and in a low smile line, less than 75% of the maxillary anterior teeth are displayed. Lip length should also be evaluated because it influences the position of the maxillary anterior teeth. In a patient with a short upper lip, the maxillary anterior teeth will be exposed in repose (Fig. 1.10), whereas in patients with a long upper lip, the anterior teeth will usually be covered.

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Fig. 1.10

A short lip poses a challenge. The transition zone may be visible

Dentate patients with a terminal dentition may present with excessive gingival display. Causes of excessive gingival display include but are not limited to

1.

Vertical maxillary excess

2.

Short upper lip

3.

Hyperactive upper lip

4.

Dentoalveolar extrusion

5.

Delayed passive eruption

6.

Multiple aetiologies [11]

The clinician must have an adequate diagnosis prior to embarking upon a treatment plan.

Edentulous should be asked to smile with and without the denture in place (Figs. 1.11 and 1.12). If the soft tissue of the edentulous ridge cannot be seen, the transition between an implant-supported prosthesis and the residual ridge crest will not be visible, resulting in flexibility for colour matching and the contour change of the prosthesis at the junction of the soft tissue. If the alveolar ridge crest is displayed during smiling, the aesthetics can be very challenging because the junction between the restoration and the gingival complex will be visible and bear aesthetic consequences. If the patient has minimal resorption, conventional metal ceramic restorations or zirconia-based restorations supported by implants can be planned and the existing soft tissue can be developed to enhance aesthetics. However, if an implant-supported denture (hybrid/profile prosthesis) is being planned, the alveolar ridge display will detract from the aesthetics. In situations like this, alveolectomy as part of a proactive protocol must be considered prior to implant placement. If alveolectomy is not performed, the restorative outcome will display the transition zone, which, ultimately, is very difficult to retreat. Alveolectomy must only be performed when there is an indication for it and the minimum amount of bone must be removed to satisfy the clinical objectives.

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Fig. 1.11

For an edentulous patient, the denture is removed and the patient asked to smile without the denture in place; the ridge should not be visible

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Fig. 1.12

If the ridge is visible, alveolectomy may be necessary to hide the transition zone, depending upon the type of restoration to be fabricated

1.5 Contours and Emergence

The contours of the restorations have to be planned from the outset. The emergence profile of the restorations should be straight as it exits from the gingival margin. Often this requires alveolectomy to create sufficient space. The restorative dentist requires this space to develop adequate mechanics, aesthetics and cleansability. This space creation must be communicated to the surgeon through the use of a bone reduction guide and it becomes the surgeon’s responsibility to provide this space [12]. One misconception about graft-less protocols is that they always require a significant amount of bone reduction. Bone reduction has to have a rationale and the minimum bone reduction must be done to satisfy the requirements of implant placement and fabrication of a biomechanically sound restoration [13].

Rationales for bone reduction include but are not limited to

1.

Adequate buccolingual width of bone to place implants

2.

Adequate space for hygiene

3.

Adequate space for biomechanics of the restoration

4.

Adequate space so that the patient can clean the undersurface

5.

Hide transition zone

6.

Improve emergence of the restoration (Figs. 1.13 and 1.14)

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Fig. 1.13

Haphazard bone reduction need not be done; there has to be a specific reason for alveolectomy

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Fig. 1.14

A bone reduction guide must be stable and have a reference point from which the surgeon can measure

1.6 Appropriate Tissue Contact

As in any aspect of restorative dentistry, the provisional is key to the success of the definitive restoration. From a patient perspective the communication of aesthetics and phonetics is important. From a clinician’s perspective, biomechanics, occlusion and cleansability are key areas of concern. The original hybrid prostheses were designed to provide a high water design. This was done predominantly to facilitate oral hygiene. Today patients often complain of food entrapment with these types of designs. The provisional/immediate load prosthesis must satisfy the following criteria:

(a)

Reduces food entrapment: Following 3 months of healing the acrylic provisional should be relined so that it compresses the tissue surface and creates a concave tissue surface allowing a convex restoration surface.

(b)

Provides cleansable contours by developing the tissue as outlined above.

(c)

Eliminates speech impairment: The t and d sounds relate to the palatal aspects of the maxillary prosthesis and this area can be adjusted to accommodate for that. The S sound is developed utilizing the closest speaking space and this should also be corrected in the provisional prior to proceeding to the definitive restoration.

(d)

The tissue contact should be intimate, but accessible to oral hygiene procedures.

(e)

The tissue surface should be highly polished.

1.7 Occlusion

Occlusion in this chapter pertains to the occlusion on the immediate load provisional restoration. Occlusion for the definitive prosthesis will be addressed in a subsequent chapter. In regard to occlusion there are no literature references citing the superiority of one occlusal scheme over another, one tooth form over another and patients’ preference of one occlusal scheme to another. Unfortunately there are no randomized controlled clinical trials guiding the clinician to develop the occlusal scheme on the immediate load provisional prosthesis. Most occlusal schemes are based on biomechanics and distribution of the occlusal forces over areas which are most likely able to tolerate them (Figs. 1.15, 1.16, and 1.17).

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Fig. 1.15

The undersurface of the immediate load provisional restorations must be convex and highly polished

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Fig. 1.16

The provisional restoration must be used to shape the tissue over time. When the clinician makes an impression the tissue surface should be concave so the restoration surface can be convex

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Fig. 1.17

Force distribution requirements of the immediate load transitional restoration

Clinical guidelines for developing occlusion include but are not limited to [14–17]

(a)

Good AP spread of implants

(b)

Minimum vertical overlap

(c)

Bilateral simultaneous contact

(d)

No interferences in lateral excursion

(e)

Cross-arch stabilization with a passive screw-retained acrylic prosthesis which has sufficient rigidity to withstand occlusal forces without breaking

(f)

No cantilevers

(g)

Occlusal contacts from canine to canine only with shimstock drag on the posterior teeth. The rationale for this approach is centred around bone quality and occlusal forces. The posterior implants are in the weakest bone quality. The occlusal forces are highest the further we go back in the mouth. The rationale is to protect the implants in the weakest quality bone being subjected to the highest occlusal forces. If this requires developing a ramp on the palatal aspect of the anterior teeth this should be completed with cold-cured acrylic resin. If the patient has a severe class two incisor relationship the above will not be possible in which case occlusal contacts are evenly distributed around the arch.

Achieving successful outcomes with graft-less solutions is significantly more challenging than with conventional restorations. Diagnosis and appropriate treatment planning are critical in obtaining a successful outcome. Implant concepts have undergone a significant evolution, not only in terms of designs, materials and surfaces but also in terms of clinical and technical management. Clearer understanding of both the surgical and restorative protocols enables the clinician to better plan the outcomes of implant therapy.

References

1.

Branemark PI, Hansson BO, Adell R, Breine U, Lindstrom J, Hallen O, et al. Osseointegrated implants in the treatment of the edentulous jaw. Experience from a 10-year period. Scand J Plast Reconstr Surg Suppl. 1977;16:1–132.PubMed

2.

US Bureau of the Census. Statistical abstract of the United States: 1996. 116th ed. Washington DC: US Bureau of the Census; 1996. p. 15, tables II, No. 16, p 17,table II, No. 17.

3.

Allen PF, McMillan AS. A review of the functional and psychosocial outcomes of edentulousness treated with complete replacement dentures. J Can Dent Assoc. 2003;69(10):662.PubMed

4.

Heath MR. The effect of maximum biting force and bone loss upon masticatory function and dietary selection of the elderly. Int Dent J. 1982;32:345–56.PubMed

5.

Turkyilmaz I, Company AM, McGlumphy EA. Should edentulous patients be constrained to removable complete dentures? The use of dental implants to improve the quality of life for edentulous patients. Gerodontology. 2010;27(1):3–10.Crossref

6.

Zitzmann NU, Marinello CP. Treatment plan for restoring the edentulous maxilla with implant supported restorations: removable overdenture versus fixed partial denture design. J Prosthet Dent. 1999;82(2):188–96.Crossref

7.

Jivraj S, Chee W, Corrado P. Treatment planning of the edentulous maxilla. Br Dent J. 2006;201(5):261–79.Crossref

8.

Tjan AH, Miller GD, The JG. Some aesthetic factors in asmile. J Prosthet Dent. 1984;51:24–8.Crossref

9.

Schwarz MS, Rothman SL, Rhodes ML, Chafetz N. Computed tomography: Part II. Pre-operative assessment of the maxilla for endosseous implant surgery. Int J Oral Maxillofac Implants. 1987;2:143–8.Crossref

10.

Wicks RA. A systematic approach to definitive planning for osseointegrated implant prostheses. J Prosth. 1994;3(4):237–42.Crossref

11.

Robins JW. Differential diagnosis and treatment of excess gingival display. Pract Periodontics Aesthet Dent. 1999;11(2):265–72.

12.

Bedrossian E. Implant treatment planning for the edentulous patient. St Louis: Mosby Elsevier; 2008.

13.

Balshi TJ, Wolfinger GJ, Balshi SF. Analysis of 356 pterygomaxillary implants in edentulous arches for fixed prosthesis anchorage. Int J Oral Maxillofac Implants. 1999;14(3):398–406. prosthodontics. JPD 1976 Dec;36(6):624-635PubMed

14.

Schnitman PA, Wohrle PS, Rubenstein JE, DaSilva JD, Wang NH. Ten-year results for Branemark implants immediately loaded with fixed prostheses at implant placement. Int J Oral Maxillofac Implants. 1997;12:495–503.PubMed

15.

Brunski JB. Biomechanical considerations in dental implant design. Int J Oral Implantol. 1988;5(1):31–4.PubMed

16.

Malo P, Rangert B, Nobre M. All on 4, immediate function concept with Branemark implants for completely edentulous mandible. A retrospective clinical study. Clin Implant Dent Relat Res. 2003;5(Suppl 1):2–9.Crossref

17.

Capelli M, Zuffeti F, Testori T, Del Fabbro M. Immediate rehabilitation of completely edentulous jaws with fixed prosthesis supported by upright and tilted implants. A multicenter clinical study. Int J Oral Maxillofac Implants. 2007;22:639–44.PubMed

© Springer International Publishing AG 2018

Saj Jivraj (ed.)Graftless Solutions for the Edentulous PatientBDJ Clinician’s Guideshttps://doi.org/10.1007/978-3-319-65858-2_2

2. Diagnosis and Treatment Planning: A Surgical Perspective

Hooman M. Zarrinkelk¹, ², ³   and Saj Jivraj⁴, ⁵, ⁶

(1)

Diplomate, American Board of Oral and Maxillofacial Surgeons, Chicago, IL, USA

(2)

Fellow, American College of Oral and Maxillofacial Surgeons, Washington, DC, USA

(3)

Private Practice, Ventura, CA, USA

(4)

Herman Ostrow USC School of Dentistry, Los Angeles, CA, USA

(5)

Eastman Dental Institute, London, UK

(6)

Private Practice, Oxnard, CA, USA

Hooman M. Zarrinkelk

Email: [e-mail]

Abstract

Treatment of edentulism has always been a challenge to the dental profession. Reconstruction of atrophic jaws caused by edentulism has necessitated sometimes complex grafting procedures. Grafting procedures carry significant morbidity and cost associated with them. Today, there is great interest from the public and dental professionals in the less invasive graft-less approaches to the atrophic jaw rehabilitation. Graft-less approaches to treatment involve specific manner of placement of sufficient number of dental implants in strategic positions of patients’ existing bone structures. The surgeon must understand the three absolute surgical requirements for successful treatment. Diagnostic factors to be considered by the surgeon to fulfil these absolute requirements for rehabilitation are discussed in this chapter.

According to the U.S. National Health Surveys conducted over the past five decades, rate of edentulism has been declining from 18.9% in 1957–1958 to 4.9% of the adult population in 2009–2012 (NHANES: U.S. Depart of Health and Human Services). The continuing decline will be offset partially by population growth and population aging such that the predicted number of edentulous patients will only decline from today’s more than 20 million to 12.2 million individuals in 2050 [1]. On the global scale the number of edentulous individuals is predicted to be much higher and therefore treatment of edentulism will be a daily challenge to clinicians for many years to come. Edentulous patients suffer from functional deficiencies caused by their removable appliances [2]. Today’s aging population is more active and social than the past generations and will demand a much higher quality of life. Lack of adequate bone volume for conventional implant-supported appliances and complex surgical treatments to correct the deficiencies are the major obstacles facing both patients and clinicians involved in their care. Over the past 30 years advances in bone and soft-tissue grafting procedures and materials have made the concept of tissue regeneration in the maxillofacial region routine and predictable [3–6]. Autogenous bone grafts, xenografts, allografts or alloplasts have been utilized to augment deficient areas of the maxilla and mandible for preparation of implant sites. In the case of atrophic edentulous jaws the gold standard remains autogenous bone. However, selection of the appropriate surgical technique and graft material remains difficult to ascertain from the heterogenic and often poorly designed available literature [7–9]. The financial burden on patient and community as well as pain and morbidity associated with grafting procedures are large obstacles to treatment. There will be increased pressure on the medical community to reign in the cost associated with treatments rendered. Clinicians are required to justify the rationale for more expensive and invasive procedures if less expensive and less invasive procedures are as effective. There is growing evidence that edentulous patients can be treated with fixed full-arch dental appliances while avoiding major grafting procedures with as few as four dental implants [10–12] (Fig. 2.1). It is with the above understanding that we begin to appreciate the great interest in the dental community to learn about the less invasive surgical concepts and protocols that rehabilitate the edentulous patient without bone grafts. The goal of this chapter is to provide a brief overview and introduction to the absolute surgical diagnostic and treatment planning requirements for surgeons and restorative dentists.

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Fig. 2.1

Successful, aesthetic and functional rehabilitation of patient utilizing graft-less approach to maxilla and mandible. Four implants per jaw were used in an immediate load protocol

Diagnosis and treatment planning of the edentulous patient is a complex and challenging task. Treatment planning of this often older and medically compromised patient population should always begin with a complete medical evaluation. In brief, any uncontrolled disease process that would compromise complete bone and soft-tissue healing should exclude a patient from implant therapy. Diabetes, osteoporosis, and cardiac and vascular disease may be of concern but if controlled are not absolute contraindications for implant therapy [13]. Currently the most concerning and absolute contraindication for implant therapy is intravenous bisphosphonate or other antiresorptive therapies [14].

The surgical evaluation of the patient’s oral condition should be systematic and methodical. The diagnostic criteria are ultimately used by the surgeon to determine the correct course of action to satisfy the three absolute surgical requirements:

1.

Space: Adequate inter-arch space required for the prosthesis

2.

Spread: Adequate A-P spread to support the prosthesis (Fig. 2.2)

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Fig. 2.2

The A-P spread is determined by the distance between the lines intersecting the platform of the distal implants and the most anterior implants. The A-P spread should be as large as possible to compensate for the magnified occlusal forces of the cantilever

3.

Stability: High primary stability of placed dental implants

The surgical diagnostic criteria discussed in this chapter will apply to a patient who is being treatment planned for a full-arch, fixed metal-ceramic, hybrid [15], profile [16] or fixed-removable (Marius type) [17] prosthetic appliance. The surgeon must evaluate the following anatomic factors for all restorative options listed:

1.

Magnitude of three-dimensional anatomical defect

2.

The visibility of the prosthetic transition line