Quintessence International, 05/2008

Subgingival crown-root fractures often present clinical problems when a restorative coverage of the fracture line conflicts with the biological width. Accepted treatment options include the extrusion of the remaining root with a conventional orthodontic appliance, surgical crown lengthening of the root, or root extraction with prosthetic tooth replacement. After considering esthetics and function, orthodontic extrusion with magnets might also be a viable alternative. In this report, a simplified method of orthodontic extrusion with magnets is presented. Keywords: appliance, crown, fracture, magnet, orthodontic, therapy, tooth

Objective: The aim of this study was to compare the influence of topical metronidazole gel application and scaling and root planing on gingival crevicular fluid variables. Method and Materials: In a split-mouth study, 39 volunteers with chronic periodontitis were treated by metronidazole gel or scaling and root planing. Clinical attachment level and probing depth were recorded, and aspartate aminotransferase (AST) and total/transformed Alpha2-macroglobulin were determined in the gingival crevicular fluid at baseline, as well as after 3 and 6 months. Results: Both treatment procedures resulted in a gain of clinical attachment-0.67 mm for metronidazole and 0.50 mm for scaling and root planing (P .001)-at the end of the study. The median probing depth was significantly reduced by 0.66 mm for metronidazole and 1.00 mm for scaling and root planing (P .001) after 6 months. No change of AST was found. Alpha2-macroglobulin was significantly reduced for scaling and root planing and metronidazole after 3 and 6 months (P .001). No significant difference was found between the 2 procedures at any variable. Conclusions: These data suggest that Alpha2-macroglobulin reflects clinical changes better than AST and that metronidazole and scaling and root planing have the same influence on clinical outcome and biochemical variables in the gingival crevicular fluid. Keywords: alpha2-macroglobulin, aspartate aminotransferase, metronidazole gel, periodontal disease

Objective: To evaluate the effect of external bleaching on the color and luminosity of fluorotic stains and adjacent, normally mineralized enamel areas by means of CIE L*a*b* colorimetry. Method and Materials: Eighteen adolescents with mild to moderate fluorotic stains were randomly assigned to either bleaching group A (n = 9) or control group B. Eligibility criteria were fluorotic stained maxillary incisors or canines and the informed consent of the participants and their guardians. Using a colorimeter, CIE L*a*b* values of maxillary incisors and canines were assessed at baseline (T1) in the center of the fluorotic stained area (F1) and at adjacent, normally mineralized enamel areas (F2). Then, external bleaching with Illuminé office (30% hydrogen peroxide, Dentsply DeTrey) was performed for 60 minutes, followed by color reassessment (T2). After 14 days (T3), a 2-week home bleaching period with a daily bleaching time of 1 hour with Illuminé home (15% carbamide peroxide, Dentsply DeTrey) was conducted with subsequent color determination (T4). Results: After completion of bleaching therapy, 96.0% of all fluorotic areas (F1) and 100% of normal enamel areas (F2) showed a significant change within group A, compared to 29.4% in control group B. Comparing the collective DE (L*, a*, b*) of F1 and F2, 60.0% of all areas showed significant differences after completion of bleaching therapy, compared to 88.0% initially. Of group B sites, 82.4% showed color differences in the beginning (T1) and 88.2% at the end (T4). Conclusion: Whereas a single 1-hour session of in-office bleaching with 30% hydrogen peroxide does not significantly affect the color and luminosity of fluorotic teeth, a 14-day period of home bleaching leads to an assimilation of the color of the fluorotic stain with the color of surrounding enamel areas due to different responses of sound and fluorotic enamel to the bleaching regime. Keywords: CIE L*a*b* colorimetry, external bleaching, fluorotic stains

Bone grafts are used for bone augmentation to ensure optimal implant placement. However, this procedure may sometimes cause sinusitis. The case of a 44-year-old woman with the diagnosis of recurrent and chronic sinusitis of her right maxillary sinus with a history of dental implant surgery is presented. After several attempts with normal standard sinusitis therapy, unrecognized bone substitute was removed from the sinus cavity, which finally led to resolution of the sinusitis. This case reiterates the importance of a careful examination, consultation, and second opinion for the selection of optimal treatment. Keywords: dental implants, foreign body, sinusitis

Objective: The clinical performance of IPS Empress (Ivoclar Vivadent) inlays and onlays was evaluated at 6 years. Method and Materials: Sixty-four porcelain inlays and onlays were placed in 29 patients, aged 21 to 70 years, by a single operator using the same clinical procedure. The restorations were examined for fracture rate; esthetics; patient acceptance; and marginal integrity, including caries, marginal discoloration, and gingival tolerance. All restorations were evaluated at the time of placement and at 1, 2, 4, and 6 years after placement. Results: At 6 years, 93.7% of the restorations were judged clinically acceptable. The fracture rate was very low (3.1%), patient satisfaction was encouraging, and the maintenance of esthetics was superior. However, marginal discoloration and integrity appeared to deteriorate with time, because of loss of marginal seal and dissolution of the luting agent. Conclusion: IPS Empress ceramic inlays and onlays are clinically acceptable. However, a disadvantage is the dissolution of the resin matrix of composite resins in oral fluids. Keywords: ceramic inlay, ceramic onlay, clinical performance, esthetics, IPS Empress system, marginal discoloration

Objective: Control of microleakage represents a challenge for posterior composite restorations. The technique for composite placement may reduce microleakage. The null hypothesis of this in vitro study was that centripetal incremental insertion of composite resin would result in less microleakage than that obtained with the oblique incremental technique or bulk technique. Method and Materials: Standardized Class 2 preparations were made in 60 caries-free extracted third molars and randomly assigned to 3 groups (n = 20): (1) oblique incremental insertion technique (control), (2) centripetal incremental insertion technique, and (3) bulk insertion. The teeth were restored with a total-etch adhesive and microhybrid composite resin. The specimens were isolated with nail varnish except for a 2-mmwide area around the restoration and then thermocycled (1,000 thermal cycles, 5°C/55°C; 30-second dwell time). The specimens were immersed in an aqueous solution of 50% silver nitrate for 24 hours, followed by 8 hours of immersion in a photo-developing solution and subsequently evaluated for leakage. The microleakage scores (0 to 4) obtained from the occlusal and cervical walls were analyzed with median nonparametric tests (P .05). Results: The null hypothesis was rejected. All techniques attained statistically similar dentin microleakage scores (P = .15). The centripetal insertion technique displayed significantly less microleakage than the oblique technique at the enamel margins (P = .04). Conclusion: None of the techniques eliminated marginal microleakage in Class 2 preparations. However, in occlusal areas, the centripetal technique performed significantly better than the other techniques. Keywords: bulk, centripetal placement, Class 2 composite resin, dentin, enamel, marginal adaptation, oblique placement

This clinical report describes the rehabilitation of an edentulous mandible with an implantsupported fixed prosthesis using an all-ceramic framework fabricated from zirconium oxide. Four interforaminal implants were inserted and allowed to heal submerged. The implant-supported fixed prosthesis was then fabricated using CAD/CAM and electroforming technology. No clinical complications were observed at the 6-month follow-up examination, and the patient was highly satisfied with function and esthetics. All-ceramic frameworks provide a high standard of esthetics; reduce the number of metals used in the oral cavity; and have a lower density compared to metals, which reduces weight in the case of large frameworks. Keywords: all-ceramic framework, CAD/CAM, edentulous mandible, electroforming, implant-supported prosthesis, rehabilitation, zirconium oxide

Objective: To evaluate the resin-dentin interfacial morphology and shear bond strength of several new dentin bonding systems on deep dentin of primary teeth after a 1-year storage period. Method and Materials: Test specimens were prepared using 5 adhesive systems (Syntac Single-Component [Ivoclar Vivadent], Prime & Bond NT [Dentsply DeTrey], Adper Prompt L-Pop [3M ESPE], Gluma One Bond [Heraeus Kulzer], and iBond [Heraeus Kulzer]) on primary deep dentin. The shear bond strength data were evaluated with Kruskal-Wallis and Mann-Whitney U tests. Debonding surfaces were examined with stereomicroscope and scanning electron microscopy (SEM). Results: The 1-day shear bond strength test values were, respectively, Adper Prompt L-Pop > iBond > Prime & Bond NT > Gluma One Bond > Syntac Single-Component, with the differences between Prompt LPop and Syntac (U = 10, P = .006), Prompt L-Pop and Gluma (U = 7, P = .002), and Adper Prompt L-Pop and iBond (U = 16, P = .03) being statistically significant. The 365-day shear bond strength values were, respectively, Adper Prompt L-Pop > Prime & Bond NT > iBond > Syntac Single-Component > Gluma One Bond, with the differences between Adper Prompt L-Pop and Syntac (U = 0, P = .000), Adper Prompt L-Pop and Gluma (U = 1, P = .000), and Adper Prompt L-Pop and iBond (U = 13, P = .01) being statistically significant. The differences between the 1-day and 365-day subgroup values of Syntac (U = 18; P = .05) and Gluma (U = 1, P = .000) were statistically significant. Almost all specimens showed adhesive failure at stereoptical examination (P > .05), with the presence of resin remnants and tags on dentin and dentinlike remnants on resin surfaces at SEM. Conclusion: Syntac and Gluma group values decreased with aging. The best values were obtained with both Adper Prompt L-Pop groups. Keywords: adhesive resin, primary dentin, shear bond strength, storage

Osteosarcoma is the most common second neoplasm in patients with retinoblastoma. The risk of occurrence of second neoplasm after retinoblastoma increases after radiotherapy and chemotherapy. A case is presented of an 11-year-old girl who had painless swelling on the left side of her face for 8 days. The patient was asymptomatic before the onset of the swelling. Biopsy of the lesion revealed tumor cells forming trabeculae of osteoid and woven bone interspersed with myxoid and cartilaginous areas. The tumor cells showed pleomorphism and hyperchromatism with increased and abnormal mitotic figures consistent with the diagnosis of osteosarcoma. Further investigations revealed no history of retinoblastoma in the family. (This case was considered hereditary, however, because of the occurence of the second neoplasm.) To the best of our knowledge, this is the first case of mandibular osteosarcoma occurring after unilateral retinoblastoma treated with chemotherapy. Keywords: chemotherapy, mandible, osteosarcoma, RB 1 gene, retinoblastoma, second neoplasm