International Journal of Periodontics & Restorative Dentistry, 02/1992

A severely damaged edentulous ridge frequently obviates the placement of dental implants or results in placing them at an angle that compromises the prosthetic restoration. This paper demonstrates the repair of severely resorbed edentulous ridges by a combination of bone allografting and the placement of a barrier membrane. The damaged edentulous ridge is treated first in this two-stage process. The implants are then installed at a second surgery.

In this study, four impression procedures were assessed for accuracy in a laboratory model that simulated clinical practice. The accuracy of stone casts with brass implant analogs was measured against a standard framework. The fit of the framework on the casts was tested by manual and visual judgment and by microscopic measurement. The measurements supported the clinical judgments. When acrylic resin was used to splint transfer copings in an impression, all casts were acceptable and were more accurate than the best of the two other procedures, which did not use an acrylic resin splint. When an impression material was used to orient the transfer copings, the accuracy was better if undercut copings remained in the impression. When impressions were made by removing an impression from smooth transfer copings and replacing the copings in the impression, the majority of casts were unacceptable.

Guided tissue regeneration procedures are intended to selectively favor healing by the periodontal ligament tissues. However, in most studies of the efficacy of guided tissue regeneration, nonresorbable barriers and membranes have been used, necessitating their surgical removal after a time. The present study employed a resorbable collagen barrier to treat Class II function invasions. The results of this treatment were compared with the results of conventional therapy. For most clinical parameters, there was no statistically significant difference in the results of treatment with or without collagen membranes. Sites treated with a collagen barrier did exhibit statistically significant improvement in probing depth and horizontal osseous support; however, these findings cannot be attributed entirely to the placement of the collagen membrane.

To rebuild the damaged periodontium to its original form, it would be ideal not only to cover the denuded root surfaces with soft tissue, but also to reconstruct the cortical plate. This paper presents four cases in which osseous grafts and guided tissue regeneration, along with root surface conditioning, were used to encourage growth of new facial bone. Some degree of success was achieved in each case.

Historically, periodontal treatment has been aimed more at the preservation and restoration of health to the periodontium than at the esthetic outcome of treatment. However, recent advances have enhanced the periodontist's ability to address esthetic concerns. To date, treatment of lost or collapsed interdental papilla has been largely unsuccessful. A case report is presented to demonstrate a technique by which a collapsed interdental papilla can be surgically reconstructed. The technique combines principles of Abram's roll technique for ridge augmentation with Evian's papilla preservation technique.

This article describes two new abutments that are intended to enhance the esthetics and function of the implant prosthesis while keeping it in harmony with the periodontium. Part 1 discusses the EsthetiCone, designed for use with multiple-unit restorations, which allows subgingival placement of porcelain for maximal esthetics. Unlike traditional abutments, the EsthetiCone is placed 4 to 6 weeks after the fixture is uncovered. Therefore, the size and type of abutment are chosen by the restorative dentist, rather than by the surgeon. Guidelines for abutment selection and placement are provided in this paper.