Quintessence International, 02/2010

Non-Hodgkin lymphomas (NHLs) in the head and neck region are malignant lymphoid neoplasms that usually originate from B-lymphocytic cell lines. Primary extranodal manifestations of this hematolymphoid tumor in the oral cavity are rare and involve the maxillary jaw including the palatal soft tissues, the mandible, and gingival tissues in patients between 60 and 70 years of age without sex predilection. This case report of an extranodal NHL in the palate of a 75-year-old patient emphasizes the importance of accurate clinical, radiographic, and histologic diagnostic procedures to avoid delayed diagnosis or inappropriate treatment strategies. Chemotherapy, radiotherapy, or a combination of the two with a regular clinical and hemic follow-up is recommended. Keywords: differential diagnosis, extranodal manifestation, hematolymphoid tumor, non-Hodgkin lymphoma, palate

Hereditary gingival fibromatosis is characterized by a slow, progressive increase in the gingival tissue that develops as either an isolated disorder or as part of the clinical characteristics of diverse syndromes. The present case report describes a Brazilian family with individuals from three generations affected. The proposed treatment was maxillary and mandibular gingivectomy with 12 months of monitoring. Keywords: collagen disorder, gingival enlargement, hereditary gingival fibromatosis

Dens evaginatus is a developmental malformation characterized by the presence of an extra cusp that takes the form of a tubercle arising from the occlusal or the lingual surface of the tooth. It is also referred to as talon cusp in the anterior teeth and Leong premolar in the premolars. Dens invaginatus is a deep surface invagination of the crown or the root lined by enamel, dentin, and pulp. Though many case reports of dens evaginatus and dens invaginatus have been found in the literature, an association of both is a rare anomaly. Only two cases of concomitance of dens invaginatus and dens evaginatus have been reported. This article is a case report of dens evaginatus and dens invaginatus involving all four maxillary incisors in a 25-year-old patient. Keywords: dens evaginatus, dens invaginatus

Location of the crown margin, marginal fit, crown material, and crown contour all impact periodontal tissues. This literature review evaluated available data on their relationship with the periodontium and also examines whether any changes in established knowledge and/or perspectives have been published during the past 30 years. Electronic and manual searches conducted for in vivo investigations in the English and German literature for 1953 to 2009 provided 64 studies. Findings indicate that the supragingival location remains the most advantageous from the periodontal point of view; esthetic demands, however, dictated an intracrevicular location of the margin in the anterior zone. Metalceramic and all-ceramic crowns show a clinically acceptable marginal fit. Ceramic materials have the lowest plaque-retaining capacity, and a normal crown contour guarantees satisfactory periodontal health and esthetics. The accompanying data confirm the results reported in the literature, revealing that nothing has substantially changed, thereby supporting current approaches. Keywords: crown contour, crown material, crowns, location of the crown margin, marginal fit, periodontium

Objective: To evaluate a comparison of open-flap debridement (OFD) with or without the use of enamel matrix proteins (EMP) for the treatment of infrabony defects. Method and Materials: Ten volunteers (38 infrabony defects) were randomized to receive OFD + EMP (test site) and OFD (control site). Clinical outcomes included mean changes in Plaque Index, Gingival Index, probing pocket depth (PPD), relative attachment level (RAL), gingival recession, width of keratinized tissue, and dental mobility at baseline and at 24 months. Results: A significant reduction of 4.21 ± 0.97 mm was observed in PPD for the OFD + EMP group (from 6.30 ± 0.99 mm to 2.09 ± 0.97 mm) and of 3.28 ± 1.23 mm for the OFD group (from 6.13 ± 0.88 mm to 2.85 ± 1.42 mm) (P .001). The reduction in PPD was statistically significantly greater for OFD + EMP compared to OFD (P = .03). The mean RAL decreased from 13.26 ± 1.88 mm to 7.57 ± 2.05 mm for the OFD + EMP group (a gain of 5.69 ± 1.96 mm) and from 13.37 ± 1.71 mm to 8.13 ± 1.34 mm (P .001) for the OFD group (a gain of 5.24 ± 1.55 mm). Gingival recession was higher in the OFD + EMP group than in the OFD group. The mean keratinized tissue significantly decreased from 4.41 ± 1.39 mm to 3.63 ± 1.54 mm for OFD flap group (P .01). Conclusion: Both treatment modalities were efficient in improving RAL and PPD. Within groups, there was a significant reduction in keratinized tissue for OFD and a significant postoperative recession for the OFD + EMP group. Infrabony defects treated with OFD + EMP showed significantly more PPD reduction when compared to OFD. Keywords: enamel matrix proteins, infrabony defects, periodontal diseases, periodontal therapy, randomized clinical trials, regenerative periodontal therapy

Objective: To evaluate whether post materials affect the color of roots, composite cores, and all-ceramic crowns. Method and Materials: Forty extracted human incisors were divided into four groups. White posts made of zirconia (Zi) or glass fiber (Gf) and gray posts made of titanium (Ti) or carbon fiber (Cf) were randomly assigned to the roots. Composite cores and glass-ceramic crowns were made. The color of the roots, cores, and crowns was captured (Spectroshade). The mean color difference (mΔE) among the groups was calculated for the following comparisons: A-root: empty root versus post and core; B-root: post and core with and without cement; C-core: white versus gray posts and cores; D-lower third of crown versus original ceramic ingot; E-center of crown versus ingot. Statistical analysis was performed by ANOVA, Kruskal-Wallis, and Sheffé tests. Results: White, as well as gray posts, induced little changes of the root color (A, B). Gray posts led to a significant discoloration of the cores (C: mΔEZi 2.0 ± 0.7, mΔEGf 1.5 ± 0.6, mΔETi 12.9 ± 5.9, mΔECf 11.2 ± 5.3; P .0001, Kruskal-Wallis) resulting in a grayish discoloration of the crowns' lower thirds (D: mΔEZi 5.7 ± 0.8, mΔEGf 6.0 ± 1.2, mΔETi 3.5 ± 1.1, mΔECf 3.9 ± 0.9; P .0001, Kruskal-Wallis). In the center of the crowns, all posts and cores induced a similar color difference (E). Conclusion: A grayish gingival shadowing cannot be reduced with white posts. In combination with glass-ceramic crowns, white posts and cores are esthetically beneficial. Keywords: glass fiber, post, post and core, titanium, zirconia

Objectives: To determine in vitro the effect of prophylaxis before tooth whitening and to evaluate a paint-on home whitening product using two methods of color analysis. Method and Materials: Ninety extracted human maxillary anterior teeth were randomly separated into a prophylaxis group or nonprophylaxis group of 45 teeth. The prophylaxis group received debridement and polishing before whitening. The two groups were randomly separated into three subgroups of 15 teeth each: placebo group, test group (Easy White, Dental Kosmetik), and positive control group (Colgate Simply White, Colgate-Palmolive). The 2-week whitening treatment consisted of applying one of the three gels twice daily according to the manufacturers' instructions. In vitro measurements included tooth color assessment using digital imaging analysis and evaluation of tooth shade by a colorimeter. Measurements were taken at baseline, after prophylaxis, and after whitening. Results: While whitening was effective with or without prophylaxis, prior prophylaxis contributed to improved posttreatment outcomes. Both test gel and positive control gel resulted in greater shade reductions and tooth color improvements compared to placebo gel (P .05). The positive control gel was not superior to test gel. Conclusions: Prophylaxis is highly recommended before use of paint-on home whitening gels. Colorimetric measurements and digital imaging analysis with a gray card are options to record the efficacy of whitening products. Digital imaging analysis has advantages: Numeric data can be evaluated, and an image of the outcome of the whitening procedure is available. Keywords: colorimeter, color measurement, digital imaging analysis, extrinsic stain, gray card, prophylaxis, tooth color, tooth whitening

Objectives: To evaluate the wear resistance of artificial denture teeth and their human enamel antagonists in a dual-axis chewing simulator. Method and Materials: Four artificial denture teeth-feldspathic ceramic, nanofilled composite resin, experimental acrylic resin with UDMA/PMMA, and interpenetrating polymer networks (IPN) acrylic resin teeth- were tested in this study. Human enamel cusps were used as antagonists. Wear resistance was analyzed by measuring the vertical substance loss and the volume loss of the denture teeth using a laser scanner after 300,000 chewing cycles. In addition, the vertical substance loss of the antagonists was evaluated using an optical macroscope. Data were statistically analyzed using ANOVA. For qualitative analysis of the wear areas, the teeth were sputter coated with gold and evaluated at magnifications of 50X and 1,000X using SEM. Results: The composite resin teeth exhibited wear that was significantly higher than that of feldspathic ceramic but lower than that of acrylic resin teeth (P .05). Acrylic resin teeth caused no measurable wear on the enamel antagonists. The wear patterns of the feldspathic ceramic and composite resin teeth can be described as attritional, while a fatigue type of wear was observed in the acrylic resin teeth. Conclusion: The lowest total vertical substance loss was found for the combination composite resin-enamel. Based on the results of this study, composite resin teeth seem to be more suitable for dentures opposing natural teeth than ceramic or acrylic resin teeth in terms of wear resistance. Keywords: ceramic teeth, human enamel, laser scanner, nanofilled composite teeth, resin teeth, SEM, two-body wear, Vickers hardness

Objectives: Recent literature has demonstrated that local proteolytic enzymes participate in periodontitis and peri-implantitis. The aim of the present study was to evaluate whether the serine proteases urokinase-type plasminogen activator (uPA) and its plasminogen activator inhibitor type 1 (PAI-1) show elevated amounts in inflamed periodontal tissues as compared to healthy oral mucosa to determine if these proteins are involved in the process of periodontal breakdown. Method and Materials: Fifty-eight patients with severe periodontitis were included in this study. Periodontal therapy was performed by means of modified Widman flaps. During surgery, samples of healthy oral mucosa and inflamed tissues were taken. Highly sensitive ELISAs allowed for determination of uPA and PAI-1 content in inflamed periodontal tissues and healthy oral mucosa. Results: The amount of uPA and PAI-1 in diseased periodontal tissue was significantly higher than in the clinically healthy oral mucosa (P = .002). However, no statistically significant correlation with the sex or age of the patients or attachment loss of the teeth was seen. Conclusion: Serine proteases uPA and its inhibitor PAI-1 participate in periodontitis. Keywords: PAI-1, periodontitis, plasminogen activator inhibitor, serine proteases, uPA, urokinase-type plasminogen activator, Widman flaps

Objectives: Several studies reported superior healing results for ProRoot mineral trioxide aggregate (MTA; Dentsply Tulsa) cement in direct pulp capping when compared to calcium hydroxide. However, this could not be confirmed by other authors. The aim of this study was to compare the reaction of MTA-treated rat pulp tissue to calcium hydroxide [Ca(OH)2]-treated rat pulp tissue in direct pulp capping after 1 to 70 days. Method and Materials: Seventy-two caries-free, maxillary right and left first molars of 36 Wistar rats were prepared with an occlusal cavity. The pulp chambers were then perforated with a sharp probe. For each of four time periods, MTA was placed on the exposed pulp of 10 molars according to the manufacturer's instructions, and Ca(OH)2 was placed on 8 molars. All cavities were then filled with dentin adhesive and flowable composite. The animals were sacrificed 1, 3, 7, and 70 days after pulp capping. The pulps were histologically analyzed (light and transmission electron microscopic) for bacterial infection, inflammatory cells, necrosis, and reparative dentin and classified according to occurrence in scores from 1 to 4. To ensure that the coronal restorations did not leak, occlusal cavities were prepared in four maxillary molars of one rat. The coronal cavity was then sealed with resin. After 70 days, the rat was sacrificed, and the molars were immersed in new fuchsin. Data were statistically evaluated with the Kruskal-Wallis test (P .05). Results: The MTA group showed statistically significantly lower signs of necrosis 1 and 3 days after pulp capping when compared with the Ca(OH)2 group (P .05). No other statistically significant differences were found (P > .05). After 70 days, all pulps displayed healthy tissue. In the leakage test no specimens revealed any dye penetration. Conclusion: MTA showed equally good results as Ca(OH)2 and can be recommended clinically for direct pulp capping. Keywords: calcium hydroxide, direct pulp capping, histology, mineral trioxide aggregate, rat, tissue reactions

Objective: To evaluate the influence of loading forces on the vertical discrepancies caused by interocclusal recording materials. Method and Materials: A custom-made apparatus was used to simulate the maxilla and mandible. Eight interocclusal records were made in each of the following groups: G1- Aluwax (aluminum wax; Aluwax), G2-Beauty Pink wax (hydrocarbon wax compound; Miltex), G3-Futar D, G4-Futar D Fast, G5-Futar Scan (polyvinyl siloxanes; Kettenbach), and G6-Ramitec (polyether; 3M ESPE). The vertical discrepancies were measured by an inductive displacement transducer connected to a carrier frequency amplifier after storage of the records for 1 hour at room temperature. Different compressive loading forces up to 1 kg were applied onto the upper part of the apparatus to evaluate the influence on the vertical discrepancies of the records. Two-way ANOVA was used for statistical analysis. Results: The compressive loading force had a statistically significant influence on the vertical discrepancies (P .01) (ie, higher forces reduced the vertical discrepancies). When a compressive force of 1 kg was applied to the upper part of the apparatus, the mean vertical discrepancies for G1 (11 ± 3 µm) and G2 (12 ± 3 µm) were statistically significantly higher than in groups G3 (1 ± 1 µm), G4 (2 ± 1 µm), G5 (0 ± 1 µm), and G6 (-2 ± 2 µm). Conclusion: A compressive force of 1 kg could be used to stabilize the cast during mounting procedures in an articulator using an interocclusal record made of polyvinyl siloxane without vertically changing the interocclusal relationships. Keywords: aluminum wax, compressive force, dental material, hydrocarbon wax compound, interocclusal record, polyether, polyvinyl siloxane