Key points
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FP1 implant restorations replicate and replace the ideal tooth form.
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FP1 implant restorations are the more conservative implant reconstruction and allow room for revisions or further bone reduction in the future if necessitated.
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FP1 implant restorations require proper diagnosis, treatment planning, surgical execution, and prosthetic design to minimize complications and ensure long-term success.
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Case selection and critical analysis of both the hard and soft tissue are paramount.
Introduction
As the demand and technology available for implant dentistry grow, historical treatment philosophies for full-arch implant-supported rehabilitations continue to evolve at the same pace. Traditional treatment planning for the full-arch implant-supported prosthesis typically involved an aggressive bone reduction ( Fig. 1 A, B) to accommodate for the material thickness of the prosthesis ( Fig. 1 C) or to hide the prosthetic tissue junction. With advancements in digital technology and implant workflows, , more conservative bone reduction and precise implant placement make the maxillary FP1 prosthetic design more attainable in contemporary implant dentistry. ,
( A ) Historical bone reduction for an FP3 prosthesis to accommodate for material thickness. ( B ) Historical bone reduction for an FP3 prosthesis to accommodate a high smile line to hide the prosthetic tissue junction. ( C ) Maxillary FP3 metal resin implant prosthesis.
Misch first described the FP1, FP2, and FP3 prosthetic designs for full-arch implant rehabilitations in 1989. The FP1 design ( Fig. 2 ) replicates and replaces the natural tooth form without replacing any of the gingival tissue. The FP2 design ( Fig. 3 ) replaces both the crown and a portion of the root which then results in a longer-than-ideal clinical crown. And finally, what was historically a very common prosthetic design is the FP3 design ( Fig. 4 ) that replaces both the crown and soft tissue.
Maxillary FP1 implant prosthesis.
Maxillary FP2 implant prosthesis.
Maxillary FP2 implant prosthesis.
In patients who present with severe existing hard and soft tissue loss from the cervical margin of the ideal tooth position in the maxilla ( Fig. 5 ), the FP2 or FP3 design may be their only option. However, in dentate patients with terminal dentition who present with minimal hard and soft tissue loss from the cervical margin of the ideal tooth position in the maxilla ( Fig. 6 ), the FP1 design should be considered. The FP1 implant restoration preserves more of the existing periodontal and bony architecture by avoiding a significant vertical bone reduction. Traditional FP3 protocols with aggressive bone reduction can leave clinician with less options. Should the patient need any revision surgery or redo of their implant rehabilitation later? This may ultimately lead the surgeon to utilize extra-maxillary bone such as quad zygomatic implant placement ( Fig. 7 ).
Patient presenting with severe hard and soft tissue loss from the cervical margin of the ideal tooth position in the anterior maxilla; not a candidate for an FP1 implant prosthesis.
Patient presenting with minimal hard and soft tissue loss from the cervical margin of the ideal tooth position in the anterior maxilla; a candidate for an FP1 implant prosthesis.
Quad zygomatic implant placement completed as revision surgery of previous failing implants.
Additionally, in patients with a high smile line ( Fig. 8 ), an FP3 design with even more vertical alveolar bone reduction was often utilized to hide the prosthetic tissue junction or transition zone. Alternatively, with an FP1 design that replicates both the natural tooth form and emergence profile, clinicians do not have to accommodate for the lip mobility or smile line in the alveolar reduction.
Patient with a high smile line that would lead to an aggressive bone reduction to hide the transition zone.
With careful patient selection, planning, and execution, clinicians can offer patients a more conservative full-arch implant rehabilitation, with the maxillary FP1 implant prosthesis while ensuring predictability and long-term success.
Case selection
Diagnostic data acquisition and planning
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Comprehensive medical history, extra-oral, and intra-oral examination
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Intra-oral and extra-oral photography series
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Diagnostic intraoral scans and facial scans
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Radiographs and CBCT analysis
Decision tree
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Is the incisal edge in the correct position? If not, move it to the ideal position.
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From the correct proposed tooth position, how much bone and soft tissue loss is present?
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Is vertical augmentation needed to achieve scalloping of the papilla and the desired result?
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Is oral hygiene adequate? If not, will the patient be able to maintain adequate hygiene during the healing phase?
Indications
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From the cervical margin of the ideal proposed tooth position in the anterior maxilla:
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Minimal to moderate bone loss
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Adequate soft tissue volume to maintain a natural emergence profile
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Examples:
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Terminal dentition
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Excessive gingival display requiring apical movement of the clinical crown
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Worn dentition with compensatory eruption
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Edentulous patients who can achieve the desired result with tissue sculpting
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Favorable interarch space
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Contraindications
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From the cervical margin of the ideal proposed tooth position in the anterior maxilla:
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Severe loss of gingival and bony architecture requiring vertical augmentation
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Relative contraindication
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Inability to maintain proper hygiene during healing
Treatment planning
Diagnostic waxup
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Restorative-driven planning based upon the diagnostic waxup and proposed ideal tooth position helps determine whether an FP1 design is indicated in a patient.
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Merging of photographs and intraoral scans ( Fig. 9 A) into CAD-CAM software for a digital waxup ( Fig. 9 B, C)
Fig. 9 ( A ) Intraoral scan to serve as reference for the diagnostic waxup. ( B ) Diagnostic waxup based on idealized tooth position. ( C ) Merging of the intraoral scan and waxup to utilize in implant planning software. ( D ) Proposed implant positions based upon the diagnostic waxup. ( E ) Areas of bone reduction visualized and measured preoperatively in implant planning software based upon the diagnostic waxup and implant sites.
Digital implant planning
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Importing the diagnostic waxup and cone beam computed tomography (CBCT) data into a digital implant planning software program
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Proposed implant positions ( Fig. 9 D), abutment heights, and potential areas of bone reduction ( Fig. 9 E) are determined based on the new ideal proposed tooth position and cervical margin of the tooth
Surgical considerations
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Prosthetic-driven implant planning
Flap design
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A flapless approach ( Fig. 10 ) or reflecting a full-thickness flap ( Fig. 11 ) both allow for prosthetically guided tissue sculpting during the immediate load-healing phase.
Fig. 10 Flapless full arch implant surgery.
Fig. 11 Full-thickness flap reflected for implant surgery.
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If the tooth positioning or cervical portion of the tooth needs to move apically, a full-thickness flap is recommended to contour and slightly reduce the alveolar ridge.
Implant positioning
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Based on the diagnostic waxup, accommodating for the height of straight or angled abutments ( Fig. 12 ), lingual access holes in the anterior and centered access holes in posterior teeth ( Fig. 13 )
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Can be determined prior to surgery during digital implant planning ( Fig. 14 )
Fig. 14 Proposed implant positions allow for predetermined multiunit heights and access holes.
Fig. 12 Straight and angled multiunit abutments placed for an intraoral conversion.
Fig. 13 Lingual access holes predetermined based upon digital implant planning.
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Consider use of pterygoid implants to eliminate a distal cantilever ( Fig. 15 )
Fig. 15 Pterygoid implants utilized to eliminate a distal cantilever.
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Guided implant placement ( Fig. 16 A, B) can help promote precise implant placement based on digital implant planning
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Just as with single implant placement, a shallow implant depth can compromise the emergence profile
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