Quintessence International, 03/2006

The aim of this article is to describe a simplified layering technique based on a biomimetic approach for large anterior Class 4 restorations. The proposed layering technique is based on a modified layering technique where palatal enamel and dentin masses are replaced with the same quantity of a microhybrid enamel and dentin shade composites, respectively, while for the thin buccal enamel layer a microfilled resin composite is used. Transparencies and, whenever necessary, white spot characterizations, are created by interposing blue and white effect masses between dentin mamelons, under buccal enamel. The combination of a microfilled composite with a microhybrid composite substituting the same quantity of lost enamel and dentin better mimics the physical and optical characteristics of the natural tooth. The biomimetic composite restoration may be considered an interesting alternative to ceramics, minimizing invasiveness, chair time, and costs for patients. Keywords: biomimetic approach, composite restorations, layering technique

A 25-year-old male patient with skin lesions of Langerhans' cell histiocytosis (LCH) was referred for periodontal treatment because of bilateral severely inflamed ulcerative periodontal lesions at the mandibular second premolar and first molar. On the left side, significant bone loss was revealed. Anti-infectious and surgical periodontal therapy resulted in significant probing pocket depth reduction and clinical attachment gains that were maintained for up to 24 months after surgery. Biopsies were taken during periodontal surgery. Immunohistochemical staining revealed that the periodontal lesions were uncommon periodontal manifestations of LCH. Reports of oral manifestation of LCH and treatment methods are reviewed. Keywords: eosinophilic granuloma, histiocytosis X, Langerhans' cell histiocytosis, periodontal disease, periodontal manifestation of systemic disease

Objective: The object of this study was to establish the 3 variables used in polishing by measuring the range of loads, speeds, and times used by practitioners when finishing and polishing samples of amalgam, resin composite, and glass-ionomer cement. These parameters could then be used to establish clinically relevant values that might optimize clinical finishing techniques. Methods and materials: Samples of the 3 materials were attached to the load cell of a universal testing machine that was attached to an X-Y plotter. Practitioners were asked to finish the samples using 4 grades of a polishing disk system. Prior to using each grade of disk, the practitioner selected a speed. The sample was finished using one grade of disk until the practitioner was satisfied with the finish achieved. The process was then repeated with the next grade of disk. From the tracings for each disk the load and time were calculated. Results: There was a wide variation in the loads, speeds, and times used by the practitioners to finish the 3 materials, and it was not possible to find any relationship among the 3 variables. It appeared that practitioners finished the materials in an arbitrary manner. Conclusion: No clear evidence was obtained to determine optimal combinations of load, speed, and time for finishing of amalgam, resin composite, or glass-ionomer cement. However, the results of this study indicate a range of values commonly used for each parameter in clinical practice, which could be useful for manufacturers in providing finishing instructions for their products. Keywords: amalgam, finishing, glass-ionomer cement, load, polishing, resin composite, speed, time

Objective: This study was conducted to compare vertical and horizontal periodontal measurements of posterior teeth on standardized panoramic and intraoral radiographs. Methods and materials: Standardized panoramic and periapical radiographs were made of 16 human skulls using ball bearings placed on the maxillary first molars to allow adjustment for horizontal and vertical magnification. Results: At 14 of 19 measurement sites there was no significant difference between measurements on the 2 radiographic film types. At 4 sites vertical measurements on panoramic radiographs were significantly larger than on periapical radiographs (0.80 to 1.37 mm). At one site horizontal measurements were significantly greater on periapical radiographs (0.88 mm). Conclusions: If there is adjustment of the raw data for magnification as suggested in this study, panoramic radiographs may be used for measurement studies in the posterior region once the patients are positioned appropriately within the focal trough of the machines and the magnification range for the posterior focal trough is used for adjustment of data. Keywords: panoramic radiograph, periapical radiograph, posterior teeth

Objective: The objective was to evaluate the influence of rubber dam isolation on the response of human pulps capped with calcium hydroxide and an adhesive system. Methods and materials: Direct pulp capping was performed in 40 caries-free human premolars scheduled for extraction as part of orthodontic treatment. The teeth were randomly divided into 8 groups (n = 5) according to the combination of treatment factors: capping agent (adhesive resin or calcium hydroxide), isolation (rubber dam or cotton pellets only), and period of evaluation (30 or 60 days). Class 2 cavities were prepared, and pulp exposures were created on the occlusal floor. After capping, all teeth were restored with Z-100 placed incrementally. After 30 or 60 days, patients were asked about their symptoms, teeth were extracted, and serial sections were evaluated. The data were subjected to a nonparametric test. Results: Overall, the histologic features showed that the pulp response was worse for groups capped with adhesive. For adhesive-capped groups, the pulp response varied from pulp necrosis to acute inflammatory cell infiltrate, and most of the pulps capped without rubber dam isolation showed severe inflammatory cell infiltrate involving the coronal pulp with chronic abscesses. For the calcium hydroxide groups, all specimens showed dentin bridge formation, regardless of the type of isolation used. Conclusion: Calcium hydroxide should be used as the material of choice for pulp capping with or without rubber dam isolation. The use of adhesive systems in vital pulp capping is contraindicated, especially if rubber dam isolation is not implemented. Keywords: adhesive system, biocompatibility, calcium hydroxide, cytotoxicity, primer, pulp therapy, resin monomer, rubber dam

A case of 2 pregnancy tumors in the same individual and at the same site within 2 years, during 2 consecutive pregnancies, despite complete eradication of the first lesion, is described. A 27-year-old woman at 32 weeks gestation was referred for gingival swelling. Gingival enlargement was pronounced on her maxillary right side, and a hemangioma was present on the lip adjacent to this mass. Despite preventive periodontal treatment the lesion continued to grow, interfering with speech and mastication, and became painful; it was therefore removed surgically. Sixteen months later, during a subsequent pregnancy, the woman returned at 20 weeks gestation for treatment of a recurrent lesion at the same site, and the lesion was excised. The roles of female sex hormones, multiplicity of vascularity, and local irritants in the development of pregnancy tumors are examined. Keywords: excision, gingival overgrowth, histopathologic analysis, immunohistochemical staining, pregnancy tumor, pyogenic granuloma

Objective: Primary teeth severely affected by amelogenesis imperfecta (AI) often show an extensive loss of enamel. Such defects are difficult to restore with resin composites, since neither the correct anatomic form nor the marginal fit can be guaranteed. Methods and materials: After clinical and scanning electron microscopic examinations were performed on replica models of 5 patients with primary teeth affected by AI, impressions were made without previous preparation by rotary instruments. Composite crowns and veneers were manufactured and luted adhesively using the total bonding technique and low-viscosity resin composite. Results: The pre-restorative scanning electron microscopic analysis showed that the dentinal tubules were exposed and that the border of the residual enamel was in the process of splitting. The preoperative oral examination had revealed tooth discoloration, masticatory disturbances, hypersensitivity, and speech problems. After placement of the restorations, patients reported improvements in tooth sensitivity, articulation, and mastication. Conclusions: A new protocol for restoration of primary teeth with an extensive loss of enamel is offered. It is quick and easy to perform, highly esthetic, and can be applied in children younger than 4 years old. Keywords: amelogenesis imperfecta, composite crown, composite veneer, total bonding

Objective: This study evaluated the clinical efficacy of 2 flowable resin composites used to restore occlusal carious lesions. Tetric Flow (Vivadent) and Esthet-X Flow (Dentsply/Caulk) are resin composites with decreased filler loading and lower viscosity compared to conventional resin composites. Method and materials: Sixty occlusal restorations (30 of each material) were placed. After tooth preparation and caries removal, each material was inserted with rubber dam isolation. Prime & Bond NT (Dentsply/Caulk) was used to bond both flowable composites, which were incrementally placed and light-cured for 20 seconds. Each restoration was evaluated at baseline (1 week after restoration placement), 3 months, 6 months, and 1 year for marginal discoloration, secondary caries, anatomic form, retention, polishability, marginal adaptation, and color match. Groups were compared at 1 year and the data analyzed statistically with a .05 level of significance. Results: A marginally significant difference in color match was observed at 1 year (favoring Esthet-X Flow). No other differences were observed between materials. Marginal discoloration significantly worsened for all restorations at 6 months and 1 year, and marginal adaptation significantly worsened at 1 year for all restorations. A positive association between preparation size and sensitivity was detected at 3 months; no association was found at 6 months and 1 year. At 1 year, restoration size was positively associated with marginal adaptation. Despite some changes from baseline, all restorations were clinically acceptable at 1 year. Conclusion: Although flowable resin composites are advocated for occlusal restorations, it is recommended that they be limited to small and moderate-sized restorations. Keywords: clinical, flowable resin composites, marginal adaptation, marginal discoloration, occlusal, retention