The treatment dilemma of missing maxillary lateral incisors-Part II: Implant restoration.

OBJECTIVE: This second of a two-part series reviews the single dental implant as the most current treatment alternative for replacement of a missing or lost maxillary lateral incisor. Assessments of dental maturity for implant placement, implant space requirements, surgical and restorative influence on soft tissue profiles, and implant success are reviewed. OVERVIEW: Recent data indicates that implant success rates are high, and esthetics and soft tissue profiles appear to be stable for maxillary lateral incisor implants. Implant placement should be assessed by dental maturity of the specific patient as opposed to chronological age, and implant spacing should be developed and assessed by all team members. CONCLUSIONS: Implant replacement of a missing lateral incisor is a predictable treatment mode if implant placement is deferred until dental maturity and then accurately placed in a well-developed site. Treatment involves more complicated planning and execution from team members than other alternatives, but innovations in techniques and materials render it a favorable alternative for lateral incisor replacement. CLINICAL SIGNIFICANCE: Implant restoration of a missing or lost maxillary lateral incisor is surgically and restoratively more complex than space closure or a resin-bonded fixed dental prosthesis but demonstrates high success rates and high esthetic potential when team members follow strict treatment protocols.

The treatment dilemma of missing maxillary lateral incisors-Part I: Canine substitution and resin-bonded fixed dental prostheses.

OBJECTIVE: Clinicians are faced with three common treatment options for the high frequency of missing or lost maxillary lateral incisors; canine substitution, a resin-bonded fixed dental prosthesis (RBFDP), or a dental implant. A review of current data and guidelines for treatment provide new insight into making the most appropriate selection. OVERVIEW: The incidence of maxillary incisor agenesis and loss is prevalent. Both canine substitution and RBFDPs exhibit esthetic and functional advantages and disadvantages. CONCLUSIONS: Most missing lateral incisors are detected at an early age as a result of congenital absence; therefore, proper treatment of these young patients is essential. Both canine substitution and RBFDPs can provide long-term success and esthetics when carefully executed. The decision should be based on the patient's expectations, their clinical presentation, cost, and the team's ability to provide the best long-term esthetic and functional prognosis for a specific patient. CLINICAL SIGNIFICANCE: Patients regularly present for treatment of missing and lost maxillary lateral incisors. The functional and esthetic aspects of canine substitution and a RBFDP should be clearly understood relative to the clinical parameters of each patient prior to treatment.

A Current Perspective on Screw-Retained Single-Implant Restorations: A Review of Pertinent Literature.

OBJECTIVE: There is a trend toward increased use of screw-retained single-implant restorations. A comprehensive literature review was undertaken to examine the data related to screw- and cement-retention and to objectively evaluate the innovations in implant dentistry that have led to this resurgence. OVERVIEW: When comparing the two options, survival and complication rates are similar, bone and soft-tissue levels are comparable, and zirconia offers esthetic advantages for both selections. Zirconia abutments with bonded titanium inserts provide esthetic alternatives to titanium abutments for both choices. Bone- and soft-tissue responses are similar, but residual cement of cement-retained restorations is associated with significant soft- and hard-tissue complications. The potential weakness of ceramic discontinuity of screw-access openings can be lessened by the incorporation of stronger ceramic materials such as zirconia and lithium disilicate. The overriding remaining indication for cement-retained restorations is to compensate for angled implants. CONCLUSIONS: Screw-retained single-implant crowns should be reconsidered for many clinical situations for the following reasons: Predictable retention and retrievability No potential for the biologic consequences associated with residual cement As with cement-retained restorations, the choice between metal ceramics or all ceramics Only one margin, at the implant/abutment interface A single abutment/crown ceramic margin that can extend gingivally to the implant interface Nearly imperceptible blend of a composite resin in ceramic abutment access openings One component instead of two, which may simplify the restorative process CLINICAL SIGNIFICANCE: Innovations in implant and ceramic technology now give screw-retained prostheses the potential for esthetic, functional, and biologic outcomes that are comparable to those for cement-retained prostheses, while providing the advantages of predictable retrievability and avoidance of residual cement. Angled implants, however, remain a major indication for cement-retained single-implant prostheses. (J Esthet Restor Dent 29:161-171, 2017).

An Evaluation of Benchmarks for Esthetic Orientation of the Occlusal Plane.

PURPOSE: This patient study was designed to measure the validity of both the horizontal and Camper's planes, which are used as benchmarks to reestablish the sagittal orientation of the occlusal plane angles in dental rehabilitation. MATERIALS AND METHODS: Profile digital photographs were made of the first 100 consenting dentate patients as they closed on an occlusal plane analyzer while maintaining natural head posture. Using a digital screen protractor, three angles were measured: the occlusal plane angle relative to the horizontal plane, and the angle between the occlusal plane and Camper's plane from both the superior and inferior borders of the tragus of the ear. RESULTS: The angle between the occlusal plane and the horizontal reference plane for the 100 patients ranged from -8.72° to +18.08° (mean +3.25°); the angle between the occlusal plane and Camper's plane, from the superior border of the tragus to the ala of the nose demonstrated a range from -8.49° to +15.16° (mean +3.03°); and the angle between Camper's plane, from the inferior border of the tragus to the ala of the nose and the occlusal plane demonstrated a range from -15.57° to +9.15° (mean -4.09°). CONCLUSIONS: Occlusal plane angles measured in this patient population with natural dentitions demonstrated a relatively small mean deviation from both the horizontal plane and Camper's plane when using the superior border of the tragus as the distal reference point, but the range was quite broad and could result in unacceptable occlusal plane angles in many patients undergoing dental rehabilitation. CLINICAL IMPLICATIONS: Both Camper's plane and the horizontal reference plane may be acceptable initial reference planes for oral rehabilitation, but additional anatomic and esthetic parameters are required for verification of an esthetically pleasing occlusal plane angle.

Implant survival and prosthetic complications of mandibular metal-acrylic resin implant complete fixed dental prostheses.

STATEMENT OF PURPOSE: This study examined and recorded the long-term implant survival and prosthetic complications of patients treated with mandibular metal-acrylic resin implant complete fixed dental prostheses delivered in a private practice setting over a 22-year period. MATERIAL AND METHODS: Records were examined for all patients in the authors' private prosthodontic practices who between April 1988 and April 2011 had received mandibular metal-acrylic resin implant complete fixed dental prostheses supported by 4 to 8 implants and who had completed at least 1 year of follow-up after implant placement. RESULTS: Forty-five patients who had received a total of 247 implants met the inclusion criteria. In the course of the 1- to 22-year follow-up period (mean 8 years and 3 months), only 2 implants failed (0.81%) in 1 patient before definitive prosthetic reconstruction, which resulted in a cumulative implant survival rate of 97.78% ±2.2%. No screws were found to be loose or fractured. Individual denture-tooth fracture and chairside repair occurred 10 times in 5 patients. Because of wear, all the teeth had to be replaced by the laboratory 10 times in 8 patients between 5 and 12 years. Framework fractures occurred 6 times and affected 3 prostheses (twice for each of the 3 patients). CONCLUSIONS: Implant failure was rare with this traditional mode of treatment and occurred before definitive restoration. The replacement of denture teeth due to wear or fracture was the most common prosthetic complication, and cantilevered frameworks exhibited a high risk of fracture when opposed by fixed prostheses. No fractures occurred for any of the frameworks opposed by complete dentures or removable implant prostheses.

Revisiting tooth preservation in prosthodontic therapy.

Dental implants have been established as long-term supports for tooth replacements, and they have profoundly altered treatment concepts of traditional prosthodontics. The use of teeth as prosthetic abutments is revisited relative to implants as predictable support mechanisms for fixed and removable prostheses. The purpose of this review is to appraise tooth preservation in a different manner while considering implants as additional and even preferred support mechanisms for dental prostheses. Data reviewed in this article include a comparison of implants and traditional prostheses and their effects on abutment teeth, the use of periodontally and endodontically compromised teeth as abutments, and prosthetic complications potentially created by healthy remaining teeth. The evidence presented suggests that the longstanding objective of tooth preservation during prosthetic treatment be appended to include the use of dental implants for fixed/removable prostheses, and to avoid or remove teeth presenting as liabilities that diminish the overall prognosis. Patients are not well served if they are faced with biologic, economic, and psychological burdens associated with ongoing revisions of dental rehabilitations using natural teeth. Dentists must use all means available to carefully evaluate remaining teeth to determine if they benefit or impair proposed prosthetic outcomes.

An interdisciplinary approach to aesthetic single implant outcomes for young patients.

Clinicians carry a significant obligation to young patients with single missing teeth to ensure that they are prepared for a lifetime of healthy dental function and long-term aesthetic success. Adolescents and young adults in need of implant treatment embody a large and growing patient population that requires distinctly different treatment approaches than those that apply to older patient groups. The primary causes of single missing teeth in young patients are trauma and congenital absence, whereas older populations typically lose teeth due to failure of traditional dental procedures. This article provides an effective approach to meet the challenges that young patients present.

The esthetic challenge of adjacent implants.

Reformation of natural-appearing sulcular and papilla anatomy between adjacent implants in the esthetic zone presents a complex challenge for the implant team. Guidelines for implant placement of adjacent implants and soft tissue development are introduced that optimize esthetic results. The rule of 3x3x3 PIE is a mnemonic, based on biologically and prosthetically driven implant placement, which maximizes the potential for optimal esthetics between adjacent implants. The 4 interdependent principles of the 3x3x3 PIE rule are as follows: 1) the platforms of the implants should be located 3 mm apical to the zeniths of the predetermined facial-gingival margins of the planned restorations, 2) the centers of the implants should be placed at a distance at least 3 mm palatal to the anticipated facial margins, 3) interimplant spacing of 3 mm is required between adjacent implant platforms, and 4) the implants should emerge through the palatal incisal edge of the ensuing crown positions. After placement of adjacent implants by the surgeon according to the rule of 3x3x3 PIE, the restorative dentist must then develop the remaining soft tissue beginning with a provisional restoration. The reformed peri-implant gingiva is then supported by the subgingival contours of the definitive abutments and crowns. If ideal gingival esthetics are not achievable, pontics or gingival-colored porcelain can be acceptable alternatives. New technologies, including platform switching, are enhancing clinicians' abilities to deliver consistent esthetic results with adjacent implants.

Esthetic potential of single-implant provisional restorations: selection criteria of available alternatives.

UNLABELLED: Provisional implant restorations are essential tools used to optimize the esthetic outcomes for single-tooth implant restorations. This article describes three groups of available alternatives and the specific options within each group including removable prostheses (interim removable partial denture, vacuum-formed appliance), tooth-supported prostheses (bonded extracted or denture teeth, cast metal or fiber-reinforced resin-bonded fixed partial denture [FPD], wire-retained resin-bonded FPD, acrylic resin provisional FPD), and implant-supported fixed prostheses (implant-retained provisional restoration). Advantages and disadvantages as well as fabrication guidelines for each option are provided. The author proposes that the restorative dentist consider eight criteria in selecting the most appropriate type of provisional prosthesis for a specific patient situation including the esthetic potential, patient comfort, treatment time, laboratory cost, occlusal clearance, ease of removal, durability, and ease of modification. The patient's esthetic expectations are critical in determining the most suitable type of provisional restoration. Esthetically pleasing provisional restorations are part of the evolving implant continuum, making implant dentistry more appealing to practicing dentists and potential patients. CLINICAL SIGNIFICANCE: Provisional restorations for single implants have evolved from temporary expedients during osseous and soft tissue integration to critical therapeutic tools used to assess patient expectations, communicate with the laboratory, and optimize definitive implant treatment. The selection of the type of provisional restoration may significantly influence esthetics during the period of implant integration and soft tissue healing. However, it is unlikely that there is a direct correlation between the type of provisional restoration used and the esthetic outcome of the definitive prosthesis.

Virtual-designed and computer-milled implant abutments.

Computer-designed and -generated implant abutments will fundamentally change the present restorative protocols for implant dentistry. Standard implant prosthetic techniques rely on implant level impressions and costly casting technology for component fabrication. Many dentists are uncomfortable making implant level impressions and resort to time-consuming conventional techniques of intraoral abutment preparation or do not offer implants as a treatment alternative. Implant abutments generated by computer-aided design and computer-aided manufacturing (CAD/CAM) are more precise than those created using traditional casting technology. This increased accuracy has specific application to implant dentistry, where precision of components may affect implant longevity, prosthetic success, and ease of restoration. Three current CAD/CAM implant abutment systems are reviewed, including an innovative digital system which eliminates the need to make implant level impressions. After placing an encoded healing abutment, an impression is made at the healing abutment level. The resulting cast is optically scanned and, using a CAD/CAM system, a patient specific definitive abutment is created. The encoded healing abutment is not removed until delivery of the abutment and final prosthesis. The ease and precision of making implant impressions at the healing abutment level, followed by patient-specific computer-generated abutments presents several benefits: restorative dentists rely less on conventional dental techniques to restore implants, inaccuracies of casting technology are virtually eliminated, laboratory technicians are freed to concentrate on higher level activities, and ultimately dentists are more likely to embrace implants as a preferred treatment option for their patients. This cutting edge technology of computer-assisted implant impressions and computer-generated abutments will likely replace traditional implant restorative protocols and become the standard for implant dentistry in the foreseeable future.

Proximal margin modifications for all-ceramic veneers.

Conventional ceramic veneers circumvent contact areas and extend palatally in the gingival third of the tooth only. Veneers are no longer considered reversible therapy. With the objective of longevity in mind, proximal extensions beyond contact areas maximize the functional and aesthetic potential of veneers and maintain conservative tooth preparations. The clinical and laboratory advantages of proximal veneer extensions for anterior teeth significantly outweigh the disadvantage of increased tooth structure removal. This article presents a modified preparation technique for the proximal extension of ceramic veneer preparations in the anterior region.

Promoting esthetic procedures in the prosthodontic practice.

The demand for esthetic services is large and growing. Emphasis on enhancing personal appearance is demonstrated in patients' increased demands for elective esthetic procedures. The techniques that have fueled this Esthetic Cultural Revolution fall under the expertise of prosthodontists. Prosthodontists, therefore, are in a position to establish themselves as the most qualified providers of these services. Prosthodontists must leverage their technical and treatment planning strengths with effective marketing strategies to address the esthetic expectations of today's patients. Marketing techniques with specific relevance to prosthodontists and esthetic dentistry are detailed.

Predictability of soft tissue form around single-tooth implant restorations.

The objective of this study was to answer important questions about gingival responses to single-tooth implants: (1) Are papilla regeneration and sulcular recession expected results? (2) Do soft tissue profiles retain their sulcular form over an extended period? and (3) Do single-implant replacements require special restorative handling to achieve predictable soft tissue form? A retrospective, photographic examination was used to follow 55 single-implant restorations in 51 patients for a period from 1 to 9 years (mean 3.5 years). Papillae regenerated in 83.9% of implants for a mean growth of 0.65 mm mesially and 0.62 mm distally. The sulcular apex receded in 59% of patients for a mean of 0.06 mm. Complete papilla fill was noted in 75% of patients examined. Short- to long-term measurements revealed that papilla regrowth continued slightly and that sulcular recession abated. Papilla regeneration around single implants was a predictable outcome in this population; sulcular recession was not a predictable finding. Papilla levels demonstrated a tendency toward increasing height, and sulcular levels remained fairly constant over the long term. Predictable soft tissue profiles were achieved with a simplified implant prosthetic protocol, progressing directly from healing abutments to definitive crowns in most cases.