Quintessence International, 06/1998

Because of their unique radicular anatomy, mandibular molars require careful treatment planning for post-and core fabrication. Indications for post-and-core fabrication for endodotiticaliy treated mandibular molars are discussed, and immediate and cast post-and-core techniques are reviewed. An alternative design for a cast post and core is also presented. (Quintessence Ini 1998:29:351-355)

Objective: Microleakage of tooth-colored restorative systems was tested in preparaiions with and without beveled gingival margins. Method and materials: A resin composite, Z-100, and two componter restoratives, Dyract and Geristor, with their accompanying adhesive systems, were placed in nonretentive cervical cavity preparations (at the cementoenamel junction), with and without a beveled gingival margin (dentin or cementum) and beveled occlusal (enamel) margins in extracted bovine teeth. Microleakage was assessed as the ratio of the extent of meihylene blue dye penetration a! the tooth-restoration interface to the length of the wall. Results; Z-100 restorations, without a gingival bevel, exhibited significantly less microleakage along the gingival wall and less microleakage overall than did ihe other materials. Dyract restorations without a gingival bevel and placed wilhoul a surface conditioner displayed greater microteakage overall than did the other groups. Conclusion: With all materials. Class V restorations with gingival bevels displayed greater microleakage than did nonbeveled margins. (Quintessence Int I998;29:356-36I) Keywords: Class V restoration, gingival margin, mltroleakage, tooth-colored restorative material

Objective: The purpose of this in vitro study was to evaluate some forms of preventing or avoiding demineralization within enamel cavity walls adjacent to amalgam restorations. Method and materials: Third molar teeth were sectioned to obtain 72 specimens, divided into one control and five experimental groups: amalgam only; varnish plus amalgam; acidulated phosphate fluoride plus amalgam; adhesive amalgam; glass-ionomer cement plus amalgam; control (amalgam only, no sujbected to a demineralization challenge). The experimental groups were subjected to pH and thermal cycling and then submitted to enamel hardness determinations. Results: Significant differences between the treatment groups revealed that the bonded amalgam technique offered the best resistance to demineralization. The use of cavity varnish resulted in greater mineral loss than amalgam placed alone. Conclusion: The use of an adhesive system, glass-ionomer cement, or acidulated phosphate fluoride under amalgam restorations may interfere with development of secondary caries.

Clinical applications of the principles of guided bone regeneration

Objective: A saliva substitute based on polyglycerylmethacrylate, lactoperoxidase, and glucose oxidase (Oral Balance) has been developed. The aim of this study was to evaluate the effect of Oral Balance on the dryness-related oral complaints in patients suffering from irradiation-induced xerostomia. Method and materials: The efficacy of Oral Balance on the dryness-related complaints of 28 patients was assessed by means of self-administered questionnaires. Each patient completed an initial questionnaire about dryness-related symptoms and then was given the moistening gel. The patients were instructed to apply the gel as often as desired. After 2 weeks and 3 months, the patients were asked to complete a progress questionnaire. The severity of xerostomia was measured with a saliva absorption method. Results: All patients suffered from moderate-to-severe xerostomia, the severity of which did not change during the experimental period. Three patients did not complete the study. In the other 25 patients, the application of Oral Balance tended to diminish the sensation of oral dryness and improve oral functioning. Statistically significant reduction of the dryness-related complaints was observed only in the patients suffering from severe xerostomia. Conclusion: Use of Oral Balance is of potential benefit in patients suffering from severe xerostomia.

Objective: The importance of occlusal balance to the control of complete dentures during function was assessed. Method and materials: The complete dentures of five patients who were having difficulty controlling their prostheses were accurately duplicated. The artificial teeth were replaced with occlusally balanced teeth. No other changes were made. Patients were asked to report their experiences with the new dentures after 1 week, 3 weeks, and 6 weeks. Results: By the end of 6 weeks, improvements in denture stability and eating comfort were reported by all patients. Conclusion: Improvements occurred when the occlusion was balanced, despite existing jaw relationship errors, fitting inaccuracies, and peripheral extension errors.

Six young adults were found to have transmigrated mandibular canines. One patient presented with two transmigrated canines. Of the seven impacted teeth, the left mandibular canine was involved In five Instances and the right ill two. In all patients, the primary canine was present in the dental arch. A supernumerary tooth was disclosed on the panoramic radiograph of two patients. Five patients underwent surgical removal of the transmigrated tooth from an iiitraoral approach. One patient experienced transient postoperative paresthesia in the zone innervated by the mental nerve. When the transmigrated canine ii accessible, and especially if it is .tymptomatic. removal of the unerupted tooth is recommended. Otherwise, it should be lefi alone and kept under observation. (Quintessence Int 1998:29:395-398)

Six young adults were found to have transmigrated mandibular canines. One patient presented with two transmigrated canines. Of the seven impacted teeth, the left mandibular canine was involved in five Instances and the right in two. In all patients, the primary canine was present in the dental arch. A supernumerary tooth was disclosed on the panoramic radiograph of two patients. Five patients underwent surgical removal of the transmigrated tooth from an intraoral approach. One patient experienced transient postoperative paresthesia in the zone innervated by the mental nerve. When the transmigrated canine is accessible, and especially if it is symptomatic. removal of the unerupted tooth is recommended. Otherwise, it should be left alone and kept under observation. (Quintessence Int 1998:29:395-398)