Quintessence International, 10/1998

Guided tissue regeneration procedures have been used successfully to reestablish periodontal attachment. However, this new attachment reportedly differs from the original attachment in strength and continuity. Enamel matrix proteins secreted by Hertwig's epithelial sheath play an important role in cementogenesis on roots and in the d evelopment of the periodontal attachment apparatus. Enamel matrix protein harvested from developing porcine teeth, or enamel matrix derivative (Emdogain), is reported to induce true periodontal regeneration (the attachment of new, acellular cementum to the underlying dentin surface). The results of experimental and clinical trials of Emdogain are reviewed, and the procedure for application of the material is described.

Objective: This study evaluated the predictability of periodontal treatment as measured by tooth loss in 114 patients. Method and materials: The patients were selected for the study if they had been treated for moderate-to-advanced periodontitis and had received continuous periodontal maintenance every 3 to 6 months for 5 years or longer. The patients averaged 53 years of age, were equally divided by gender, and were maintained an average of 12.5 years. Patients were retrospectively assigned, according to the number of teeth lost following active periodontal treatment, to the well-maintained group (96 patients, 0 to 3 teeth lost), downhill group (15 patients, 4 to 9 teeth lost), or extreme downhill (three patients, 10 to 23 teeth lost) group. Teeth were retrospectively assigned a questionable or hopeless prognosis. Results: Of the 2,899 teeth present during maintenance care, 378 had a questionable prognosis because of furcation involvement, and 63 (16.7%) of these teeth were lost. Of the 529 nonfurcated teeth that had a questionable prognosis, 68 (12.9%) were lost during the maintenance phase of treatment. Ninety-dix teeth were given a hopeless prognosis, and 32 (33.3%) of these teeth were lost. Surgical treatment of teeth with questionable or hopeless prognosis did not improve the retention of these teeth in the downhill and extreme downhill groups. Conclusion: The prognosis of a periodontally compromised tooth in individual patients is difficult to predict accurately. A hopeless prognosis is more accurate than a questionable prognosis in predicting tooth loss in these patients.

Objective: Marginal leakage of amalgam restorations may lead to secondary caries and pulpal damage. The purpose of this study was to determine the effect various cavity liners might have on microleakage. Method and materials: Mesio-occlusodistal amalgam restorations with margina on enamel and entin were treated with different liner materials (an adhesive system, a topical fluoride gel, a cavity varnish, and a glass-ionomer cement) in vitro. Following restoration, the teeth were submitted to thermocycling in a stained solution and sectioned to allow assessment of microleakage. Results: On enamel, the control group (no liner) and the glass-ionomer-lined group had equivalent leakage scores and were superior to every other group. On dentin, only the glass-ionomer specimens had superior performance. The cavity varnish and fluoride-lined specimens exhibited the highext leakage scores. Conclusion: The use of liners does not reduce microleakage on amalgam restorations when the cavity margins remain on enamel. On dentin margins, a glass-ionomer liner can reduce microleakage.

Objective: The purpose of this study was to evaluate the effectiveness of bleaching a nonvital tooth with an open pulp chamber while simultaneously bleaching the other vital teeth with 10% carbamide peroxide. Method and materials: Ten discolored nonvital teeth were treated. Each nonvital tooth was prepared as in the conventional walking bleaching fashion, so that the gutta-percha was sealed from the pulp chamber. The 10% carbamide peroxide was injected into the chamber of the nonvital tooth and loaded into the custom-fitted tray for all teeth. The nonvital teeth were bleached from both the inside and the otuside. The patient closed the orifice with a cotton pellet during the day and changed the cotton pellet after meals. The patient applied fresh solution nightly. Results: All teeth were successfully lightened. The time required to lighten the nonvital tooth was related to the duration of the discoloration. Conclusion: With proper patient selection and education, this technique can provide an effective way to lighten nonvital and vital teeth simultaneously, especially where extended treatment time may be required for difficult discolorations.

Electrosurgery has been used in dentistry for several decades, but the technique is not widely practiced. This article briefly explains the principles of electrosurgery and attempts to clear up some misunderstandings about the healing of electrosurgical wounds. Clinical application of electrosurgery for the management of some common oral conditions is also described.

Trauma to a primary mandibular central incisor in a rare case of dilaceration and duplication of crown with hypercementosis of the root in the permanent successor. This tooth was extracted. This article highlights the consequences of trauma to a primary tooth for a developing permanent successor.