International Journal of Periodontics & Restorative Dentistry, 03/2005

Densely sintered alumina- and zirconia-based restorations were introduced to dentistry in the early 1990s and became a popular treatment modality, especially in situations requiring complete-coverage restorations. The use of industrial technologies for the fabrication of the restoration, simple clinical management, and pleasing esthetic outcome have made these restorations an attractive treatment alternative. This article reviews the nature of the materials used and the technologies involved and provides indications for clinical case selection and tooth preparation.

During a period of 12 months, 139 patients with 164 intraoral pathologic lesions were treated with a CO2 laser. Intra- and postoperative complications and the method of pain control during and after surgery were recorded. The diagnostic evaluability of the 133 soft tissue biopsy specimens sent for histopathologic analysis was examined, and the clinical and histopathologic diagnoses were compared. Nine intra- and six postoperative complications occurred. Pain control during CO2 laser surgery could be performed with a topical anesthetic in almost one third of the lesions; in the other 111 lesions, a local anesthetic had to be applied. For pain relief after the operation, 101 patients (72.7%) used only an adhesive wound paste, without any additional oral analgesic. The thermal damage from the CO2 laser on the borders of the biopsy specimens never interfered with the pathologist's establishment of a firm diagnosis. The CO2 laser is an appropriate instrument for excisional biopsies of oral soft tissue lesions. Intra- and postoperative complications were minimal, pain relief during and after surgery could be achieved in many cases through topical anesthetics, and incisional or excisional biospsies caused no diagnostic problems because of collateral thermal damage of the specimen from the laser.

The objective of this study was to quantify new bone formation from biopsies of demineralized freeze-dried bone allograft (DFDBA) and freeze-dried bone allograft (FDBA) following ridge and sinus augmentations. Ninety-three patients who received maxillary sinus or ridge augmentation grafts agreed to core biopsies of their grafts when the implants were placed. Samples ranged from 6 to 36 months postgrafting. These samples were sectioned, stained, and examined histomorphometrically. Seventy-two FDBA and 21 DFDBA samples were examined, and the mean percentages of new bone formed were 41.89% and 41.74%, respectively. There was no statistical difference, irrespective of graft site.

This case report describes the use of orthodontic traction to recover soft tissue lost a round a maxillary right central incisor with major external root resorption associated with severe gingival recession. Traction of the residual root for 1 month produced a gingival appearance in harmony with the adjacent teeth. After the placement of an implant, a correct emergence profile was obtained, giving an optimal esthetic outcome. After a 3-year follow-up, complete regeneration of soft tissue persisted around the implant-supported crown.

The aim of this study was to investigate postsurgical periodontal probe penetration by using clinical information and histometric data. Thirty-eight three-walled defects were created in four dogs, then maintained for 3 months. Subsequently, 26 defects were subjected to periodontal surgery (surgical group), while 12 defects served as controls. The dogs were sacrificed at 4, 8, 12, and 16 weeks. Immediately before sacrifice, endodontic silver points were placed in the gingival crevices as substitutes for periodontal probes and fixed on the teeth. Following block sections, histologic and histomorphometric evaluations were undertaken: location of the probe tip in relation to the apical termination of the junctional epithelium, length of new junctional epithelium in relation to the apical junctional epithelium, and mean length of connective tissue adhesion in relation to the apical junctional epithelium. Probe tips were located -1.37 ± 1.73 mm and -0.20 ± 0.15 mm apical to the apical junctional epithelium for the surgical and control groups, respectively, at 4 weeks, while the probe tip was located 0.58 ± 0.31 mm and 0.40 ± 0.20 mm coronal to the apical junctional epithelium, respectively, at 16 weeks. Length of new junctional epithelium in relation to apical junctional epithelium was significantly less for the surgical than the control group at 4 weeks (0.73 ± 0.60 mm vs 1.19 ± 0.02 mm) and 8 weeks (1.77 ± 0.52 mm vs 2.15 ± 0.00 mm). There were no significant differences between the groups in regard to connective tissue relationship to the apical junctional epithelium. Periodontal probing is not recommended for at least 2 months after surgical procedures; before this stage, probing forces may damage the soft tissue-tooth interrelationship.

This case report describes a simple method for augmenting tissue at prospective palatal connective tissue donor sites. The patient was referred for treatment of facial marginal tissue recession on the maxillary left canine. Clinical examination indicated that the palatal mucosa was thin and did not provide an adequate volume of soft tissue for donor harvesting, precluding the use of a palatal connective tissue graft for treatment of the recession defect. Sterile lyophilized bovine collagen sponge was therefore surgically inserted between a full-thickness palatal flap and bone at the prospective donor site. Eight weeks postoperative, the augmented palatal donor area showed a significant clinical increase in thickness and volume and served as a connective tissue donor source in the treatment of the facial marginal tissue recession. Histologic analysis of the donor tissue demonstrated normal structure, fibrous connective tissue, and abundant collagen. Clinical examination 6 months following surgery showed complete root coverage, with tissue texture, volume, and color similar to those of the adjacent soft tissue. Healing of the donor site was uneventful. This case report demonstrates that sterile lyophilized collagen sponge material may be used to augment palatal donor connective tissue and can subsequently be used as a donor source for soft tissue grafting.

This study compared the natures of various guided tissue regeneration (GTR) membranes impregnated with amoxicillin or tetracycline. Whether the antibiotics-loaded membranes enhance the attachment of the periodontal ligament cells in the presence of oral pathogens was further analyzed. S mutans and A actinomycetemcomitans diminished the attachment of periodontal ligament cells onto the membranes as evaluated by SEM analysis. These bacterial effects on cellular attachment could be reversed using the antibiotics-loaded membranes. The information obtained in this study is valuable for the future application of antibiotics-loaded membranes during GTR therapy.

The effects of citric acid and acidulated phosphate fluoride on the surface roughness of autoglazed and overglazed all-ceramic IPS Empress materials were analyzed. Atomic force microscopy was used to measure the roughness. Citric acid solution (2.00%) was applied for 8 hours, simulating 2 years of exposure. Acidulated phosphate fluoride gel (1.23%) was applied for 32 minutes, simulating 2 years of fluoride therapy. Acidulated phosphate fluoride caused a significant roughening effect on both autoglazed and overglazed specimens.

Human histologic evidence of periodontal regeneration following treatment of intrabony defects with enamel matrix derivative has yielded inconsistent results in recent case reports. A 46-year-old woman presenting one deep intrabony defect at the distal root of a mandibular first molar scheduled for extraction was selected for enamel matrix derivative therapy. During surgery, a notch was placed at the most apical level of calculus on the experimental root. Nine months postsurgery, a block section including the distal root and surrounding periodontal tissues was obtained and processed in a mesiodistal plane. Histologic analysis demonstrated two different patterns of healing along the proximal and furcal surfaces. Regeneration with new cellular cementum, bone, and periodontal ligament with functional fiber orientation was observed on the distal aspect of the root, whereas the furcal surface healed through ankylosis. This report underlines the biologic variability in wound healing following enamel matrix derivative therapy in periodontal intrabony defects and within the same defect. Host-specific intrinsic and/or extrinsic factors accounting for this variability remain to be investigated.

From April 22 to 24, 2004, the Osteology 2004 Symposium took place in Lucerne, Switzerland, where practitioners convened with researchers to address emerging solutions for hard and soft tissue challenges encountered when treating implant and periodontal deformities. Esthetics emerged as a topic of particular interest, as contemporary clinicians are increasingly encountering patients seeking improvement in their appearance. The Scientific Chair of the congress, Dr Daniel Buser, emphasized that, "Continued education is the key to achieving high-quality results in practice." More than 2,000 participants from 51 countries were eager to discover new treatment regimens for augmenting jawbone and soft tissues. The sessions were an example of the progress that ensues when practitioners, clinical researchers, and industry work in union toward a common goal. Osteology 2004 was organized by the Geistlich Foundation, which was established in August 2003 by ten scientists representing seven countries. This was the first of many activities that will promote application-oriented research relating to tissue regeneration. Since this high level of continuing education was not available to all of our readership, it has been decided to publish the following abstracts (only the principal author is listed). We anticipate that they will provide meaningful information.