Implant Placement in the Esthetic Zone

Surgical placement of dental implants in the anterior zone requires careful treatment planning, particularly in terms of fixture selection and implant positioning. Among the many clinical considerations, soft tissue contours and emergence profile outcomes are critical factors in determining esthetic results.

Due to the numerous variables that influence decision-making, general practitioners may not feel comfortable in providing this service, especially when bone and tissue volumes are less than ideal. In light of this, Decisions in Dentistry asked Scott H. Froum, DDS, of the State University of New York at Stony Brook School of Dental Medicine to share his perspectives on placing implants in the esthetic zone. The bottom line, according to Froum, is that understanding the factors that influence esthetic and functional outcomes is imperative when determining which patients a provider feels comfortable treating — and which should be referred to a specialist.

Editor’s Note: The views expressed in this interview are the author’s.

EMERGENCE PROFILE

How does the implant fixture affect the emergence profile?

One of the more important factors that can affect emergence profile is the three-dimensional (3D) placement of the implant fixture into the alveolous. If the implant is placed too coronally, there won’t be sufficient length or “running room” to create an anatomic emergence of the crown from the gingiva. In addition, the diameter of the implant platform plays an important role in creating emergence profiles. For example, it will take a lot more room to develop a molar emergence profile from a narrow-diameter platform versus a wide-diameter platform.

What elements should clinicians consider in order to ensure a proper emergence profile?

Factors such as 3D implant placement, plat­form diameter, abutment selection, crown temporization and restorative material are key considerations that will help practitioners achieve a proper emergence profile.

TISSUE CONTOURING

What is a reasonable expectation in soft tissue augmentation to achieve an esthetically pleasing emergence profile?

Having a sufficient amount of keratinized tissue around the implant will help practitioners properly contour the soft tissue envelope. By comparison, molding mucosa is a more difficult, if not impossible, task.

Please discuss preservation of the interdental papillae.

The best way to ensure papillary preservation is not to reflect or incise the papilla. There are many papilla-sparing surgical incision designs that will provide operators with adequate access to the alveolous, without the need for reflecting the papilla.

IMPLANT POSITIONING

What are your thoughts about using narrow-diameter implants and other implants designed for use in a narrow anterior ridge?

In my experience, narrow-diameter implants — those having a platform of 3.0 mm or less — are a good solution for replacing mandibular central teeth and incisors, as well as maxillary lateral incisors. In addition, they work well in mandibular atrophic ridges for implant overdentures. Narrow-diameter implants have also been used effectively as temporary implants for fixed-prosthesis cases in which conventional-diameter implant sites are healing following placement. Outside of these indications, their use is less predictable.

Please discuss the use of surgical stents, guides and similar tools.

Offered in analog and digitally fabricated versions, surgical guides play a key role in successful outcomes in anterior implant procedures. These guides also serve as an extremely valuable conduit for sharing information between the surgeon and restorative dentist. Practically speaking, they help surgeons place implants in a prosthetically driven manner.

IMPLANT SELECTION

To your way of thinking, what are the most important considerations for implant selection in the esthetic zone?

While there are many considerations when selecting an implant fixture for the esthetic zone, implant diameter is critically important, as clinicians want at least 2 to 3 mm of buccal and lingual/palatal bone surrounding the implant. Other key considerations include the abutment-implant connection, surface geometry, and the fixture design; for example, in certain case parameters, a provider might choose a tapered, rather than a straight, implant fixture.

Are ceramic implants useful in the anterior esthetic zone?

Ceramic implants can be useful in the anterior esthetic zone providing they allow the option of using custom abutments, as this will help address any angulation concerns the clinician might have. In terms of ceramic devices, another aspect to consider is that some ceramic designs are one-stage implants with insertion torque limitations.

Where do you stand on the use of screw-retained versus cemented restorations for esthetic zone implants?

To my way of thinking, anytime an implant can be screw retained, it should be. If the implant is placed properly and the screw access can be directed towards the cingulum, screw retention is the superior option because it is retrievable. Even if implant angulation is a concern, an angled, screw-retained abutment and lingual/palatal slot access can be used.

If cementation is necessary, a radiopaque cement should be used. In addition, extreme care is needed when cementing the crown restoration to avoid excess cement in the peri-implant sulcus, as residual cement has been shown to contribute to peri-implant disease and, ultimately, implant failure.

CHOICE OF ABUTMENTS

Please discuss the use of custom abutments.

As noted, custom abutments are a great option when clinicians face angulation issues, restorative space issues and/or occlusal issues. In addition, many manufacturers do not offer angled stock abutments or stock abutments that are capable of being screw retained. The drawback of custom abutments, of course, is they typically cost more than prefabricated stock components.

FINAL CONSIDERATIONS

Are there any additional considerations for treatment planning and delivery that will help ensure successful outcomes when placing anterior implants?

During the treatment planning and delivery stages, the best way to ensure long-term esthetic success is to envision what the implant and restoration will look like in 10 years. For example, we know that even after the 18- to 20-year-old age mark, craniofacial development still occurs and teeth and gingiva move, while implants do not. In addition, occlusal patterns can change over time, which affect the implant restoration. Open contacts, gingival recession, adjacent teeth extrusion and passive eruption of the gingiva can all take place, which means clinicians must plan as best they can for these possibilities.

In terms of long-term outcomes, retrievability of the restoration is important in case a repair or remake is needed. Finally, open communication is essential during treatment planning, delivery and follow-up care. Patients should be informed that the body is dynamic and the implant restoration may need to be remade in the future. Such communication helps ensure realistic expectations and may contribute to better patient cooperation in ongoing professional care.

The author has no commercial conflicts of interest to disclose.

From Decisions in Dentistry. March 2018;4(3):22,24.