Biologically Contoured Esthetic Implant Restorations
Course Number: 684
Course Contents
Placement of a Well-contoured Provisional Restoration/Custom Healing Abutment
Traditionally, stock healing abutments are attached to the implant at the time of implant placement or second-stage surgery to promote healing of the peri-implant soft tissues.39 However, their rounded configuration creates a circular soft-tissue contour that typically does not replicate the original soft tissue architecture of the tooth being replaced. This consequently results in the fabrication of an unesthetic final restoration with contours that are difficult for the patient to maintain hygienically.39,40
Provisional restorations are widely used in the anterior esthetic zone (after implant placement or the second stage surgery ) for immediate restoration of esthetics and function.41 In the anterior regions of the mouth, the extracted tooth/crown may be modified and used as a provisional restoration to maintain the soft tissue architecture.42
Immediately placed implants in conjunction with immediate provisional restorations help maintain and preserve the soft tissue height and gingival profile established by natural teeth.36,43,44 However, when implant placement is delayed, ridge resorption leads to the loss of osseous structures, overlying mucosal tissues, and contour of the edentulous area.45 In such situations, a provisional restoration may be utilized to condition the mucosal tissues around the implant so that an ideal emergence profile can be achieved in the final restoration.46 Conditioning, or shaping, of the soft tissues is a gradual and time-consuming process necessitating multiple appointments. At these visits the transmucosal contour of the provisional restoration is modified using flowable composite resin or acrylic resin to reshape the peri-implant tissues and sculpt the desired morphology (Figures 9, 10 & 11).46-48
Figure 9. Provisional restoration placed for conditioning tissues.
Figure 10. Improvement in soft tissue contours (occlusal view) observed after removal of the provisional restoration.
Figure 11. Improvement in soft tissue contours (Facial view) observed after removal of the provisional restoration.
The contour of the provisional restoration crown also helps determine the contact-point position with the adjacent teeth. The proper positioning of the contact area is critical to positively affect the development or maintenance of the interproximal papilla.49 To maintain the interproximal papilla/facilitate its growth, the distance from the interproximal bone crest (of the adjacent tooth) to the apical extent of the contact point (established by the provisional restoration) should be less than or equal to 5 mm.49,50
A well-contoured provisional restoration not only helps the mucosal tissue grow and develop optimally but it also serves as a template for the final restoration.51 In addition, the provisional restoration helps in assessment and understanding the patient’s expectations which are also critical to the success and acceptance of the final clinical outcome.51 The disadvantages of provisional restorations include the need for extra time, materials, components, technical skill, and added financial liability.41 Further, minimal implant stability at the time of surgical implant placement is required to ensure stability for immediate provisionlization.
The placement of an overcontoured provisional restoration may result in excessive pressure on the mucosa thereby leading to transient ischemia, tissue inflammation, and/or necrosis.46 This may be clinically visible as blanching of the peri-implant tissues during seating of the provisional restoration.48 If the blanching persists for more than 10 minutes, the provisional restoration crown should be removed and its critical and subcritical contours should be evaluated and adjusted/reduced as necessary.
Placement of a Customized Healing Abutment
Immediate provisional restorations may be contraindicated in the posterior quadrants of the oral cavity (as increased masticatory forces adversely affect osseointegration of the implant during the healing phase) and in implants with suboptimal primary stability.41,47, 50 They are also avoided in patients exhibiting a deep anterior bite, signs of bruxism, and/or malocclusion.50 In such situations, a customized healing abutment may be utilized for soft tissue conditioning.50 The submucosal portion of the customized healing abutment is essentially the same as a provisional restoration, however, it lacks occlusal contact (Figures 12 & 13).50
A customized healing abutment may be placed at the time of implant placement or the second-stage surgery.53 When placed at the time of implant surgery, it conditions the soft tissues,47 contains bone graft materials,53 covers the surgical site (without the need for an invasive procedure),54 maintains the alveolar bone contour,53 prevents food lodgment,53 and eliminates the need for a second-stage surgery and placement of a provisional restoration.52,53 The custom healing abutment aims to reproduce the natural cervical contours of the extracted tooth thereby maintaining the soft tissue architecture during osseointegration and/or healing of the peri-implant mucosa (Figure 14).55 Its contours may be gradually modified until the desired soft tissue form is achieved. However, its fabrication is time-consuming and requires multiple steps both chairside and in the dental laboratory.56 Also, if the resin is incompletely polymerized it may cause soft tissue irritation in some patients.56
Figure 12. Custom healing abutment attached to the implant (occlusal view).
Figure 13. Custom healing abutment attached to the implant (buccal view).
Figure 14. Maintenance of soft tissue formed by the custom healing abutment.