Quintessence International, 08/2010

Benefits of cone beam computed tomography (CBCT) over traditional panoramic radiography for diagnosis and treatment planning have been reported. This article presents a case where CBCT was used to identify the potential route of caries infection from the oral cavity to an impacted mandibular second molar. Keywords: caries lesion, cone beam computed tomography, impacted molar

Objectives: To evaluate fixed dental prostheses (FDPs) and single crowns made of zirconia substructures veneered with new fluorapatite veneering porcelain. Method and Materials: Thirty-eight patients received 18 FDPs and 50 single crowns. Zirconia substructures were fabricated by a CAD/CAM system and veneered using the powder buildup technique. All restorations were cemented with glass ionomer. Baseline evaluation was performed 2 weeks after cementation with recall examinations at 12, 24, and 36 months by calibrated investigators. SEM was performed on replicas of all restorations. Survival probabilities according to Kaplan-Meier were calculated. Results: The mean service time was 35 (± 14) months. After 3 years of clinical service, three biologic and five technical failures were recorded. All failures occurred in the FDP group. One FDP was removed after biologic failure of one abutment tooth. The Kaplan-Meier survival probability was 88.2% after 35 months for all types of failures and 98.5% concerning restorations in service. The type of restoration showed significant influence on the survival probability (P .001, log-rank test). No influence on gingival parameters from the restorations was observed compared to control teeth. Conclusions: Zirconia substructures veneered with fluorapatite veneering porcelain seem to be a reliable treatment option. More research has to be conducted to investigate differences between single crowns and FDPs. Keywords: CAD/CAM, fixed dental prosthesis, fluorapatite veneering porcelain, porcelain chipping, single crown, zirconia

Objectives: To date, there have been no studies on the outcome of osseointegration of alveolar bone around dental implants inserted with piezoelectric osteotomy versus conventional osteotomy. The aim of this study was to compare the radiographic differences, through evaluation of peri-implant bone density, between implant insertion using traditional surgical technique and piezoelectric technique. Method and Materials: Forty patients were selected whose treatment consisted of a minimum of two implants placed in nonpathologic native bone. A single type of implant surface (SLA) was chosen. The implants were placed following the manufacturer protocol for traditional surgical technique and piezoelectric technique. Radiographs were taken following surgery and 30, 60, and 90 days after surgery. The bone density was studied with the densitometry application. Results and Conclusion: All patients completed the study period with success. Despite a limited number of treated patients, the results of this pilot study demonstrated that (1) piezoelectric implant site preparation promotes better bone density and osteogenesis, and (2) the piezoelectric technique is predictable, with a 100% success rate in this study. Keywords: bone density, implants, osseointegration, surgery, ultrasound

Objective: To present bismuth subgallate as a simplified and efficient method for promoting hemostasis at palatal donor sites, as evaluated by measuring hemostasis time and delayed bleeding. Method and Materials: Ten patients received the bismuth subgallate paste as a topical hemostatic agent, while another 10 patients received moistened gauze pressure. The time to obtain complete hemostasis, defined as no visual bleeding, was recorded for each subject. Results: Bismuth subgallate paste was found to decrease hemostasis time, when compared with moistened gauze pressure. The mean hemostasis time for the bismuth subgallate group was significantly shorter (2.6 ± 0.7 minutes) when compared to the moistened gauze group (7.2 ± 1.4 minutes). While delayed bleeding was observed in the moistened gauze group, no statistically significant difference was found between the groups (P = .10). Conclusion: The use of bismuth subgallate as a topical hemostatic for palatal wounds may be an option when performing free soft tissue grafts. Keywords: bismuth subgallate, hemostatic agent, palatal donor sites

Objective: The aim of this prospective study was to evaluate the concept of intraoral welding as a suitable technique for the placement of a final restoration in the edentulous patient on the same day as surgery. Method and Materials: Any patient with a completely edentulous arch who was considered eligible received a fixed restoration supported by an intraorally welded titanium bar. Definitive abutments were connected to the implants and then welded to a titanium bar using an intraoral welding unit. This framework was used to support the definitive acrylic restoration, which was fitted on the same day as implant placement. Restoration and implant success, mean marginal bone loss, pocket probing depth, and bleeding on probing were assessed over a 36-month follow-up period. Results: Twenty-six patients with an edentulous maxilla and 34 patients with an edentulous mandible, with a mean age of 57.1 years (SD = 17.9, n = 60), were consecutively treated with 324 immediately loaded implants. No fractures or radiographically detectable alteration of the welded framework was evident. A total of 321 (99.1%) implants osseointegrated and were clinically stable at the 6-month follow-up. At the 36-month follow-up, the accumulated mean marginal bone loss was, respectively, 0.967 mm (SD = 0.361) for the maxillary cases and 1.016 mm (SD = 0.413) for the mandibular cases. Conclusions: It is possible on the same day of surgery to successfully rehabilitate the edentulous patient with a fixed definitive prosthesis supported by an intraorally welded titanium framework. Keywords: implant dentistry, osseointegration, prosthodontics

Intraoral presentation of follicular lymphoma is rare, and only three cases in the palate have been reported to date. The present case report describes an uncommon case of follicular lymphoma affecting the palate. The clinical aspect was similar to salivary gland neoplasm, and an incisional biopsy was important to establish the correct diagnosis and consequently to plan the treatment. Also discussed is the differential diagnosis among follicular lymphoma, mucosa-associated lymphoid tissue lymphoma, and follicular lymphoid hyperplasia with regard to the histopathologic and immunohistochemical features. Keywords: differential diagnosis, follicular lymphoid hyperplasia, follicular lymphoma, immunohistochemistry, lymphoma, palate tumors

Objectives: Guided bone regeneration with alloplastic bone graft substitutes has a high impact in surgical dentistry nowadays. In the future, the orthodontist will inevitably be confronted with patients with such a medical history. A review of the literature was performed to investigate present materials used, indications, and concerns and problems in interdisciplinary treatment of patients with nonautogenous bone grafts. Method and Materials: An electronic key word search in the literature database PubMed of the US National Library of Medicine and The Cochrane Library (CENTRAL) of the Cochrane Collaboration was performed. Numerous journals were searched manually, and the reference lists of all identified papers related to the topic were reviewed to warrant completeness. All abstracts of the identified publications were screened in duplicate by two autonomous reviewers. Inclusion criteria were the use of a nonautogenous bone graft followed by orthodontic tooth movement or a tooth eruption through the grafting material. Results: The total number of identified publications was 37. It was possible to divide these into two major topics, orthodontic tooth movement in bone graft and tooth eruption through bone graft. Besides experimental setups, indications were periodontal defects, cystic lesions, and alveolar clefts. Here, different types of bone graft were used. The following tooth movement was partially uneventful and sometimes attended by serious adverse effects. The resulting articles presented a low level of evidence and showed diversity in question, methodology, and type of publication. For this reason, it was not possible to perform a quantifying review. Therefore, the articles are discussed in a descriptive manner with regard to the topic in question. Conclusion: Both orthodontic tooth movement and tooth eruption through grafted bone are not only possible but also might provide promising results. However, more research on this interdisciplinary treatment is necessary to avoid risks and achieve more safety in orthodontic treatment of these patients. Keywords: bone defect, bone graft substitutes, guided bone regeneration, orthodontics, tooth eruption, tooth movement

Objective: To investigate the effect of audiovisual distraction (AVD) with video eyeglasses on the behavior of children undergoing dental restorative treatment and the satisfaction with this treatment as reported by children, parents, dental students, and experienced pediatric dentists. Method and Materials: During restorative dental treatment, 61 children wore wireless audiovisual eyeglasses with earphones, and 59 received dental treatment under nitrous oxide sedation. A Frankl behavior rating score was assigned to each child. After each treatment, a Houpt behavior rating score was recorded by an independent observer. A visual analogue scale (VAS) score was obtained from children who wore AVD eyeglasses, their parents, and the clinician. Results: General behavior during the AVD sessions, as rated by the Houpt scales, was excellent (rating 6) for 70% of the children, very good (rating 5) for 19%, good (rating 4) for 6%, and fair, poor, or aborted for only 5%. VAS scores showed 85% of the children, including those with poor Frankl ratings, to be satisfied with the AVD eyeglasses. Satisfaction of parents and clinicians was also high. Conclusion: Audiovisual eyeglasses offer an effective distraction tool for the alleviation of the unpleasantness and distress that arises during dental restorative procedures. Keywords: audiovisual distraction, behavior management, pediatric dentistry, video eyeglasses

Objectives: To analyze the diagnostic value of the clinical and radiographic investigation of the interface of two-piece implant systems under the variables crevice size of the microgap, clinical experience, radiograph exposure time, prosthesis design, and type of evaluation. Method and Materials: A simulated mandibular cast with five screw-retained implants (Straumann) providing three different prosthesis designs displayed artificially created proximal, visually inaccessible microgaps of unequal sizes or junctions without any measurable gap formation. Three groups of 15 investigators each with a different degree of clinical experience evaluated the implant-abutment interfaces of the cast clinically and radiographically. The investigation was conducted on the basis of a scoring form adapted from the receiver operating characteristic (ROC) 5-choice method. Radiographs were prepared in two exposure times (0.1 second, 0.2 second) for each junction. Radiographs of the initial situation without any measurable gap formation were shown as a control and to detect false-positive scores for each gap size. A 10-point SEM measurement of the junctions served for standardization purposes. Statistical methods included ROC analysis, kappa analysis, and a regression analysis (α = .05). Results: Gaps greater than 150.9 µm (P .001) were detected 227% more frequently and gaps greater than 189.7 µm 292% more frequently via radiographic examination. Kappa values were adequate for the radiographic examination and unsatisfactory for clinical examination. Prosthetic superstructure and exposure time did not adversely affect the diagnosis. Clinical experience improved the detection of microgaps significantly. Conclusion: A relationship between the size of microgaps and the examiners' ability to detect them can be established. Whereas tactile examination alone is not accurate enough, radiographic analysis affiliated with a certain degree of clinical experience possesses features for an adequate clinical management of restoration defects. Keywords: abutment, clinical investigation, exposure time, implant, microgap, prosthetic superstructure, radiographic examination

Paraneoplastic pemphigus is a rare autoimmune disease characterized by polymorphous mucocutaneous lesions in association with underlying neoplasia. We report two Chinese patients, one with chronic lymphocytic leukemia and the other with thymoma. Both of them initially presented with severe oral erosion with lichenoid features that resisted all the regular therapy. The routine histology was not typical in both patients, with features of liquefaction degeneration of the basal cell layer and subbasilar lymphocytic infiltration. Important differential diagnoses for the two cases include lichenoid eruption secondary to chemotherapy, pemphigus, and pemphigoid. Immunohistologic testing played an essential role in the diagnoses. Direct immunofluorescence shows both intercellular and basement membrane deposition of immunoreactants. Indirect immunofluorescence using rat bladder as the substrate has been shown to be an inexpensive and reliable diagnostic tool. Our patients' clinical and immunopathologic features were consistent with a diagnosis of paraneoplastic pemphigus, a special subset of pemphigus. Patients' conditions were improved after high-dose systemic corticosteroid therapy after underlying malignancies were treated. Keywords: diagnosis, direct immunofluorescence, indirect immunofluorescence, oral presentation, paraneoplastic pemphigus

Objective: To evaluate the color stability of composite resin types designed for esthetic anterior restorations when continuously exposed to various staining agents. Method and Materials: Thirty-six disk-shaped specimens were made of each of 12 composite materials (1 microfilled and 11 hybrid composites). After dry storage at 37°C for 24 hours in an incubator (INP-500, Memmert), the initial color of each specimen was assessed by a calibrated reflectance spectrophotometer (SpectroShade). Specimens were immersed in five staining solutions or dry stored (control). All specimens were kept in an incubator at 37°C for 99 days. Test solutions were changed every 14th day to avoid bacteria or yeast contamination. After 99 days of storage, spectrophotometric measurements were again performed and L*a*b* scores once more recorded to determine the color changes. Results: Wine proved to have the highest staining potential followed by coffee, tea, orange juice, and cola, which had the lowest staining potential. The highest color change measured against a white background was observed for Durafill (Heraeus Kulzer) in wine (ΔE = 62.3), while the least staining was found for Enamel HFO (Micerium) in cola (ΔE = 3.5). The highest color change measured against a black background was observed for EsthetX (Dentsply) in wine (ΔE = 46.0), while the least staining was observed for Enamel HFO in cola (ΔE = 2.5). Conclusion: Composite staining susceptibility proved to vary among composite structure and brands. Potential discoloration might be limited by dietary restriction based on such in vitro evaluation. Keywords: composite resins, esthetics, staining

Objective: To measure directly the thickness of the palatal mucosa using sharp cannulas and to evaluate potential correlations with gender and body mass index (BMI). Method and Materials: Thirty-three participants (19 women) 23 to 41 years of age (27.8 ± 4.1) were examined. Mucosal thickness from maxillary left canine to left second molar was measured at defined sites under local anesthesia using singleuse cannulas with silicone stops. The cannulas were evaluated on video images. Results: The mean thickness of the palatal mucosa was lowest in the first molar areas (4.39 ± 1.05 mm), increased considerably in the canine/premolar regions, and was highest in the second molar areas (5.75 ± 1.78 mm). Women exhibited higher mucosal thickness values than men in all tooth regions (P .05 for the canine and the molar regions). Multivariate analysis revealed a relation of palatal mucosal thickness to gender and BMI. Conclusion: The thickness of the palatal mucosa is characterized by variations that correlate with tooth regions, gender, and BMI. Direct measurements with sharp cannulas provide higher thickness values than measurements with blunt periodontal probes or ultrasonographic measurements. This finding is important particularly with regard to the hard palate as a donor site for connective tissue grafts.

Objective: Since little is known about the effects of carbamide peroxide (CP) containing fluoride (F) or calcium (Ca), this study evaluated the effects of experimental and commercially available bleaching agents, with or without F and Ca, on enamel. Method and Materials: Sound enamel slabs were randomly divided into six groups (n = 10): placebo gel (PLA); Whiteness (WHI-10% CP; FGM); Opalescence F (OPA-10% CP+F; Ultradent); Pola Night F (PN-10% CP+F; SDI); and experimental gels: 10% CP + F (CPF) and 10% CP + Ca (CPCa). The samples were submitted to 6-hour gel applications daily for 14 days and stored in remineralizing solution after treatment. Enamel microhardness measurements were performed at baseline and after bleaching. In addition, the analytical concentrations of F and Ca and the pH of the water used to rinse the bleached surface were analyzed by means of ion-selective electrode, atomic absorption spectroscopy, and pH meter, respectively. Results: Enamel surface microhardness significantly decreased after bleaching with nonenhanced 10% CP (WHI). The chemical analyses suggest F uptake promoted by high-concentrate F bleaching gels (CPF, OPA, and PN) and a F loss with nonenhanced 10% CP bleaching gels (PLA, WHI). CP agent enhanced with Ca (CPCa) also caused Ca enamel uptake. Conclusion: Enamel was susceptible to mineral changes during bleaching treatment, but mineral loss was minimized by the addition of F and Ca to bleaching agents.