Management of the Edentulous Patient: Removable Implant Prostheses.

For an edentulous patient who does not wish to cope with mastication impairment associated with a conventional denture, either in the maxilla or mandible, function can be restored with a fixed or removable implant-supported prosthesis. This article addresses management of situations when it is preferable to restore an edentulous arch with a removable implant-supported prosthesis. The differences in treatment planning concepts as they relate to the maxillary and mandibular arches are highlighted, and advantages of a bar-retained overdenture versus unsplinted implant-supported overdentures are discussed. A logical sequential approach to case management is delineated starting with determining tooth position after casts are articulated.

Hierarchy of restorative space required for different types of dental implant prostheses.

BACKGROUND: Management of the full and partially edentulous arch requires an understanding regarding the amount of vertical and horizontal restorative space that is needed for different types of dental implant prostheses. Failure to design a prosthetic construct without considering space issues can result in a rehabilitation with diminished stability, poor esthetics, and inadequate contours. Therefore, available restorative volume must be computed before initiating therapy to ensure proper prosthesis design. TYPES OF STUDIES REVIEWED: The authors searched the dental literature for articles that addressed space requirements for different types of dental implant prostheses and found a few on this subject. RESULTS: The dental literature indicates there is a 3-dimensional hierarchy of restorative space necessary for different types of implant constructs. The minimum amount of vertical space required for implant prostheses is as follows: fixed screw-retained (implant level): 4 through 5 millimeters; fixed screw-retained (abutment level): 7.5 mm; fixed cement-retained: 7 through 8 mm; unsplinted overdenture: 7mm; bar overdenture: 11 mm; and fixed screw-retained hybrid: 15mm. These dimensions represent the minimal amount of vertical rehabilitative space that can accommodate the above implant prostheses. With respect to horizontal space, computations are needed to account for the discrepancy between an implant and tooth position. CONCLUSIONS AND PRACTICAL IMPLICATIONS: Restorative spaces for each type of prostheses are restoration specific and should be considered during treatment planning to facilitate proper case selection and enhance patient satisfaction.

The Need to Replace a Missing Second Molar With a Dental Implant Restoration: Analysis of a Controversial Issue.

Whether or not a second molar should be replaced after its removal is debatable. To assess the evidence and discuss the pros and cons of replacing a missing second molar with a dental implant restoration, the authors searched the literature for articles that evaluated the following factors: chewing efficiency, tooth loss, super-eruption, extrusion, over-eruption, and occlusal interferences. The data indicated that replacing a second molar provides some increased masticatory performance, but first-molar occlusion facilitates 90% chewing efficiency. Super-eruption of unopposed posterior teeth occurs frequently, and approximately 20% of these teeth extrude 2 mm, but the degree of over-eruption is not strongly related to the incidence of occlusal interferences. It was concluded that after a patient/dentist discussion regarding second-molar replacement, it is the patient's preference that usually dictates the decision. In this regard, if a patient perceives a chewing deficiency or dislikes having a gap in his or her dentition after the loss of a second molar, the tooth could be replaced with an implant-supported restoration. However, if the patient does not recognize any reduced masticatory efficiency, replacement of a second molar typically is unnecessary. This is due to the findings that most extrusion over time is minor and usually does not affect occlusal function; also, concerns about over-eruption can be managed in a preventive manner, and/or unopposed second molars can be monitored. Nevertheless, super-eruption of teeth can complicate restorative cases.

Open contacts adjacent to dental implant restorations: Etiology, incidence, consequences, and correction.

BACKGROUND: The aim of this investigation was to evaluate the potential causes, clinical significance, and treatment of open contacts between dental implant restorations and adjacent natural teeth. TYPES OF STUDIES REVIEWED: The authors searched the dental literature for clinical trials in humans that addressed the incidence of open contacts that develop after implant restorations are placed next to teeth. RESULTS: The authors found 5 studies in which the investigators addressed the incidence of open contacts after implant restorations are inserted next to teeth. Results from these studies indicated that an interproximal gap developed 34% to 66% of the time after an implant restoration was inserted next to a natural tooth. This event occurred as early as 3 months after prosthetic rehabilitation, usually on the mesial aspect of a restoration. CONCLUSIONS: The occurrence of an interproximal separation next to an implant restoration was greater than anticipated. It appears that force vectors cause tooth movement and an implant functions like an ankylosed tooth. PRACTICAL IMPLICATIONS: Clinicians should inform patients of the potential to develop interproximal gaps adjacent to implant restorations, which may require repair or replacement of implant crowns or rehabilitation of adjacent teeth. Furthermore, steps should be taken to check the continuity of the arch periodically. If the clinician detects an open contact, it is prudent to monitor for signs or symptoms of pathosis so that prosthetic repair of the gap can be initiated, if needed. These problems could add to treatment costs and decrease overall patient satisfaction related to implant treatment.

Dental Cone-Beam Scans: Important Anatomic Views for the Contemporary Implant Surgeon.

Intraoral cone-beam computed tomography (CBCT), otherwise known as volume imaging CT scan, provides 3-dimensional images of mandibular and maxillary structures. These images offer highly accurate and valuable diagnostic information to facilitate treatment planning for implant cases. This article serves as a primer on how to read and interpret CBCT cross sectional views. It identifies anatomic structures of interest and discusses their clinical relevance.

Nerve damage related to implant dentistry: incidence, diagnosis, and management.

Proper patient selection and treatment planning with respect to dental implant placement can preclude nerve injuries. Nevertheless, procedures associated with implant insertion can inadvertently result in damage to branches of the trigeminal nerve. Nerve damage may be transient or permanent; this finding will depend on the cause and extent of the injury. Nerve wounding may result in anesthesia, paresthesia, or dysesthesia. The type of therapy to ameliorate the condition will be dictated by clinical and radiographic assessments. Treatment may include monitoring altered sensations to see if they subside, pharmacotherapy, implant removal, reverse-torquing an implant to decompress a nerve, combinations of the previous therapies, and/or referral to a microsurgeon for nerve repair. Patients manifesting altered sensations due to various injuries require different therapies. Transection of a nerve dictates immediate referral to a microsurgeon for evaluation. If a nerve is compressed by an implant or adjacent bone, the implant should be reverse-torqued away from the nerve or removed. When an implant is not close to a nerve, but the patient is symptomatic, the patient can be monitored and treated pharmacologically as long as symptoms improve or the implant can be removed. There are diverse opinions in the literature concerning how long an injured patient should be monitored before being referred to a microsurgeon.

Utilization of d-PTFE Barriers for Post-Extraction Bone Regeneration in Preparation for Dental Implants.

Guided bone regeneration (GBR) can be used to restore a defective alveolar ridge after extractions before or in combination with implant placement. It may also be employed after extractions to reduce crestal bone resorption and maximize bone fill of sockets. Resorbable or nonresorbable barriers (eg, expanded polytetrafluoroethylene [e-PTFE]) can be used when performing GBR procedures, but they need to be completely submerged to attain optimal results. Dense polytetrafluoroethylene (d-PTFE) is a type of nonresorbable barrier that circumvents the necessity to attain primary closure after placement of bone grafts, thereby reducing patient morbidity. This article addresses topics pertaining to d-PTFE utilization, including characteristics and advantages of d-PTFE barriers, time needed for osteoid tissue to become impervious to penetration by flap connective tissue, relevant clinical studies, and limitations of available data. Clinical photographs and radiographs of successfully treated cases are presented to illustrate the efficacy of d-PTFE barriers in regenerating defective bony plates after extractions.

A simplified impression protocol for fabrication of anatomical, cement-retained CAD/CAM abutments.

The complexity and labor-intensive nature of making implant-level impressions may inhibit some clinicians from recommending dental implant treatment. This paper describes a simplified impression technique for fabricating anatomical, cement-retained abutments without removing or inserting implant components. Using digitally coded healing abutments, this protocol bridges the gap between traditional impressions and computer-aided abutment manufacturing. Basic logistic considerations are reviewed, as well as other biomechanic and esthetic advantages, that should optimize overall treatment outcomes.

Treatment of maxillary jaws with dental implants: guidelines for treatment.

Maxillary implant prosthetic treatments may be considerably more difficult to accomplish when compared to the corresponding treatments for patients with edentulous or partially edentulous jaws. The objectives of this article include descriptions of diagnostic records and their impact on treatment success, and criteria clinicians should use to determine whether fixed or removable prostheses are the treatment of choice in any given situation. Specific criteria and clinical guidelines will be identified for use in the treatment planning process. Determination of optimal tooth positions and their relationships to residual ridges or extraction sites are one of the critical factors in determining designs for maxillary implant prostheses. Prosthetic designs (fixed or removable) should be determined by clinicians prior to placing implants; removable prostheses should not be considered to be the "fall-back" treatment option if fixed treatments become unavailable secondary to loss of implants or other clinical complications. Inherent differences between fixed and removable prosthetic treatments are critical for clinicians to understand, as they often include key points for clinicians explaining the features of fixed/removable-implant prostheses to patients. Appreciation of the differences between fixed and removable prostheses is critical for patients and clinicians to make informed decisions.

Treatment options for the edentulous mandible: clinical application of the two-implant overdenture.

Edentulism is a public health concern that affects millions of individuals. While this condition has been treated for years with implant-supported hybrid prostheses, this modality does not always represent the optimal restorative solution for all patients. The two-implant mandibular overdenture provides greater retention than does a conventional mandibular denture and, due to its cost and efficacy, can significantly improve an edentulous patient's quality of life. This article reviews the nutritional and social aspects of edentulism in affected patients and its treatment with two-implant overdentures.