International Journal of Periodontics & Restorative Dentistry, 02/2004

Esthetic rehabilitations are characterized by a sequence of well-structured clinical and laboratory steps, during which different kinds of impressions are required. This review presents a survey of the most clinically relevant physical properties that characterize final impression materials and their interactions with the products they are commonly in contact with. The principal steps of an esthetic rehabilitation involving a diagnostic phase, together with a rational step-by-step approach to final impressions, are described. The one-step/double-mix impression using polyvinyl siloxane materials associated with a "double cord" gingival displacement is explained.

Human cultured gingival epithelial sheets were used as an autologous grafting material for regenerating gingival tissue in the maxillary left and mandibular right quadrants of a patient with chronic desquamative gingivitis. Six months postsurgery in both treated areas, there were gains in keratinized gingiva and no signs of gingival inflammation compared to presurgery. In the maxillary left quadrant, preoperative histopathologic findings revealed the epithelium was separated from the connective tissue and inflammatory cells were extensive. After grafting with the gingival epithelial sheets, inflammatory cells were decreased and separation between epithelium and connective tissue was not observed. The human cultured gingival epithelial sheets fabricated using tissue engineering technology showed significant promise for gingival augmentation in periodontal therapy.

This study evaluated an anorganic bovine-derived xenograft (Bio-Oss Collagen) in the treatment of human periodontal defects. Four patients with intrabony defects on teeth that were treatment planned for extraction were enrolled in the study. Presurgical measurements of probing depth, attachment level, and recession were recorded. The surgical procedure consisted of flap reflection, debridement of the osseous defects and root surface, placement of a notch through calculus into the root surface, topical application of a tetracycline paste to the root surface, grafting with Bio-Oss Collagen, and flap closure. Three of the eight defects examined received a resorbable collagen barrier (Bio-Gide) in addition to the bone graft. Patients were seen every 2 weeks for plaque control and review of oral hygiene measures. Six months postsurgery, clinical parameters were rerecorded prior to en bloc resection of teeth and adjacent graft sites. The majority of sites showed a favorable clinical response with respect to probing depth reduction and clinical attachment gain. Histologic analysis demonstrated new bone, cementum, and periodontal ligament coronal to the reference notch in two of the eight specimens. Two sites demonstrated new attachment, and four showed a long junctional epithelium. Periodontal regeneration is possible following a bone-replacement graft of Bio-Oss Collagen.

The goal of periodontal treatments is to eliminate bacteria and their products without damaging cementum surfaces. Nonsurgical treatments are often limited by the inability of curettes to access the most apical zone of the pocket. While ultrasonic mini-inserts have been used for nearly 10 years now, their effect on dental tissues has not been tested. The purpose of the present study was to compare a new series of mini-inserts to Gracey curettes, which are the reference in nonsurgical treatments. Two experienced periodontists conducted root treatments on teeth destined for extraction using regular clinical criteria. One face of each root was instrumented using a Gracey curette, and the opposite face was instrumented using an ultrasonic mini-insert. After the instrumentation procedure, the teeth were prepared for examination by secondary electron (topographic features) and backscattered electron (organic and mineral composition) microscopy. Differences in surface composition between teeth treated by the two periodontists were noted and were related to the lateral pressure exerted. Calculus removal was less effective when strong lateral pressure was exerted using the ultrasonic mini-inserts, while more cementum was removed and more scratching occurred with both manual and ultrasonic instruments. In all cases, the ultrasonic mini-inserts allowed greater apical access. The new ultrasonic mini-inserts were as effective as manual curettes in eliminating plaque and calculus. The shape of the mini-inserts made them more effective in apical zones. The amount of damage to the cementum depended on the lateral pressure exerted by the periodontist.

Exposed metal crown margins in the porcelain-fused-to-metal technique might be an esthetic problem. Therefore, all-ceramic crown systems are used for restoring teeth and dental implants. In addition, the gray color of a titanium implant might hamper the esthetic appearance of the entire reconstruction in cases of thin peri-implant soft tissue or tissue retraction. To further improve the esthetic aspect of dental implants, efforts are undertaken to develop implant systems fabricated out of tooth-colored materials that are biocompatible and able to withstand masticatory forces. One such material may be zirconia. The present article presents a case in which an all-ceramic custom-made zirconia implant-crown system was used for the replacement of a single tooth.

Treatment planning for the placement of an implant in a site with a thin crestal ridge should address the probability that a buccal dehiscence will result. The aim of the present investigation was to perform guided bone regeneration (GBR) around implants with buccal dehiscences and evaluate the outcomes of using autogenous bone grafts harvested from three different intraoral sites. Forty-six Osseotite implants, 4 mm in diameter, were placed in thin crestal ridges, resulting in an uncovered implant surface from the buccal aspect. The lengths of the buccal dehiscences ranged from 3 to 7 mm as measured from the implant cervix to the most apical extent of the uncovered threads. A standard GBR technique was carried out to augment the bone defect around the buccal implant surface immediately after implant placement. The cases were divided into three groups according to receipt of an autogenous bone graft from the ramus, tuberosity, or mandibular symphysis. In all cases, e-PTFE membranes were used to cover the grafted areas. Grafted sites were exposed after 6 months, membranes were removed, and residual distance between the implant cervix and most uncovered thread was recorded. All grafting materials were able to produce a certain degree of bone regeneration. In terms of bone change level, the three groups were not equal. The mandibular symphysis group exhibited the highest mean bone growth level, followed by the ramus group. The tuberosity produced the poorest result. Mandibular and ramus autogenous bone grafts represent the best choice in materials for GBR procedures around implants, while tuberosity bone grafts can be used as an alternative.

Current procedures in periodontal plastic surgery probe the limits of the copious blood supply available to the periodontal tissues. None reaches for these limits more consistently and meets with less forgiveness than soft tissue grafting for the interdental papilla and root coverage in esthetically sensitive areas. Gingiva contains the only soft tissue naturally created to survive and function interproximally and facially over avascular root surfaces. Preliminary results suggest that the supracrestal gingiva, used as a free graft for the above purposes, may have an uncommon capacity for perfusion and survival. More investigation is necessary to confirm the validity of this concept. The gingival unit transfer is introduced through three case reports that describe its use for root coverage and replacement of intact but pathologically involved or esthetically compromised papillae.

Rapid crestal bone resorption following maxillary tooth loss is further accentuated in the posterior regions because of pneumatization and enlargement of the maxillary sinuses. A treatment rationale that allows preservation and/or augmentation of vertical available bone at the time of posterior maxillary tooth extraction may offer numerous therapeutic benefits. The present study comprised 14 patients in whom 18 posterior maxillary teeth with no evident bone between the tooth apex and sinus floor, as estimated through preoperative radiographic analysis, were carefully extracted using a palatal approach. The empty alveolus was thoroughly debrided and incrementally filled with tricalcium phosphate. The graft material was gently pushed beyond the empty alveolus to elevate the sinus membrane using an osteotome. Primary soft tissue closure over the grafted sites was achieved by a rotated palatal flap. The distance between bone crest and sinus floor was radiographically estimated 6 to 7 months after the first procedure. Another procedure was then carried out to place the 10- to 14-mm implants, together with a bone-added osteotome sinus floor elevation. At uncovering, all implants were clinically stable, with no signs of infection. The presented surgical procedure performed at the time of extraction of posterior maxillary teeth in close proximity to the sinus floor allowed placement of implants of proper length and width, together with a bone-added osteotome sinus floor elevation during a second procedure.

This study evaluated the efficacy of Emdogain enamel matrix proteins as a regenerative material in interproximal vertical defects both clinically and radiographically. Patients aged 18 to 45 years and diagnosed with chronic or aggressive periodontitis were included. Sixteen intrabony defects in eight patients were surgically treated using a split-mouth design. Emdogain placement was done at experimental sites. Since both chronic and aggressive periodontitis patients were included, an attempt was made to interpret results between the two types of cases. Postsurgical measurements at 9 months revealed no significant difference in mean pocket depth reduction, clinical attachment level gain, amount of defect fill, or defect resolution between control and experimental groups. Mean pocket depth reduction and amount of defect fill were significant in both groups. The results were interpreted separately for chronic and aggressive periodontitis cases. This study demonstrated no added advantage of using Emdogain compared to surgical debridement alone. Further long-term and large-sample-size evaluation is required to prove Emdogain's consistent efficacy.