Quintessence International, 08/2008

Objective: To evaluate the optical integration of 4 contemporary composite resin materials used for incisoproximal restorations and the natural layering concept. Method and Materials: Miris 2 (M2; Coltene Whaledent), Gradia Direct (GD; GC), Enamel Plus HFO (HFO; Micerium), and Filtek Supreme Plus (FSP; 3M ESPE) composite resins were used to consecutively restore 6 extracted incisors with incisoproximal restorations using the natural layering concept, mimicking the natural anatomy of the tooth with only 2 composite resin masses (dentin and enamel). Following each restoration, the specimen was allowed to rehydrate for 2 weeks and was then photographed under standardized conditions (direct, indirect, and fluorescent lights). Six independent evaluators scored each light condition using an optical integration score on a scale from 1 to 4 (1 = worst optical integration, restoration can be easily distinguished from remaining tissues; 4 = optimal optical integration, restoration "invisible"). Mean optical integration scores (from the 6 evaluators) were analyzed with a 2-way analysis of variance (ANOVA) (composite resin brand and light condition). Pooled data of M2 and HFO (single-hue systems) and GD and FSP (multiplehue systems) were also analyzed with a 2-way ANOVA (shade system and light condition). Results: M2 obtained the highest optical integration scores (P < .03), followed by GD and HFO (not significantly different, P = .99). FSP showed the least favorable optical behavior (P < .0001), which is explained in part by the lack of fluorescence and possible inappropriateness for use with the natural layering technique. Single-hue systems (M2 and HFO) achieved better optical integration (P < .02) compared to multihue systems (GD and FSP). Conclusions: For M2, the simplified natural layering concept produced incisoproximal restorations with excellent optical integration. GD and HFO are also suitable for this technique. FSP failed to produce acceptable optical integration in the present study. Keywords: composite resin, dental esthetics, natural layering technique, optical integration

Depending on etiology, the esthetic treatment of dyschromia may involve vital tooth- bleaching techniques. Hydrogen peroxide is the active molecule used for such procedures; however, its action mechanism is not clearly understood. Moreover, a variety of contradictory studies make difficult the evaluation of the safety of bleaching techniques. The purpose of this article is therefore to review the available literature (1) to describe the physicochemical properties of hydrogen peroxide and (2) to assess the safety of its use as a vital tooth-bleaching agent. Indeed, based on hydrogen peroxide's capacity to generate free radicals that diffuse throughout the dental hard tissues, concerns have been addressed regarding the adverse effects that bleaching products can induce on the enamel and dentin structures, pulp, and bonding to a composite resin system. Moreover, during self-application of home bleaching products, hydrogen peroxide is released into the oral cavity and ingested. Some questions have therefore arisen concerning its toxicity and its possible carcinogenicity. Keywords: adverse effects, bleaching, cancer, carbamide peroxide, enamel, hydrogen peroxide, tooth, toxicity

Objective: To determine if the use of panoramic radiographs is a reliable method of predicting maxillary sinus membrane exposure or perforation during extraction of maxillary teeth. Method and Materials: The radiographs of 72 patients were evaluated before extraction of maxillary teeth, and a prediction was made whether exposure or perforation of the sinus membrane was likely. This decision was based on the proximity of the root tip to the radiographic floor of the maxillary sinus. The extraction site was then evaluated to determine if the sinus membrane was visible or if a perforation had occurred. Results: Possible exposure or perforation of the maxillary sinus was predicted in 27 patients. In this subset of patients, it actually occurred 4 times (14.8%). However, it also occurred 5 times when not predicted (11.0%). Conclusion: Use of panoramic radiographs is not a reliable method to predict the likelihood of sinus involvement following the extraction of posterior maxillary teeth. Keywords: extraction, maxillary sinus, panoramic radiography, sinus perforation

Objective: The incorporation of dental implants into removable partial dentures is a common clinical practice, but it is poorly documented in the dental literature. The purpose of this retrospective case series study was to evaluate the survival of endosseous dental implants used in restoring partially edentulous patients with implant-supported removable partial dentures (ISRPDs) of different configurations, based on up to 10 years of follow-up. Method and Materials: The sample consisted of 23 consecutively treated partially edentulous patients, who, between 1996 and 2005, had a total of 44 implants placed in different arch sites and who were treated with ISRPDs. The mean age was 44.2 ± 7.5 years at inclusion. Mean follow-up time from implant placement was 31.5 months (range, 9 to 120 months). Smoking status, arch configuration before and after implant placement, follow-up time from implant placement, implant location, implant dimensions, implant and abutment survival, and overall satisfaction (assessed by questionnaire) with the restoration are presented. Results: The overall implant survival rate was 95.5%; 2 implants failed. Kennedy Class I in the maxilla (6 patients) followed by Kennedy Class II in the mandible (4 patients) were the most prevalent arch configurations before implant placement. Arch configuration was modified by implant placement in 6 patients (26.1%). During follow-up, 1 abutment tooth was lost 2 years after prosthesis delivery. All patients were satisfied with their prosthesis. Conclusions: Implant-supported removable partial dentures could serve as a longterm predictable treatment modality. Careful patient selection, with an appropriate maintenance and recall system, is recommended to obtain satisfactory results. Keywords: denture satisfaction, implant-supported removable partial denture, implant survival

Objective: Nonmyeloablative stem cell transplantation (NST) is a relatively new type of hematopoietic stem cell transplantation (HSCT) that has gained wider use in the last decade. Oral effects of NST have not been described. The goal of the study was to evaluate the oral mucosal effects, including oral acute graft versus host disease (aGVHD), in patients undergoing NST in comparison to patients undergoing myeloablative HSCT. Method and Materials: This prospective, longitudinal pilot study included 34 consecutive patients undergoing HSCT. Demographic data were collected. Patients were evaluated every 2 weeks between baseline and day 100 posttransplantation. Statistical methods included univariate and multivariable regression analyses (level of significance, P < .05). Results: Patients undergoing NST had significantly less oral aGVHD (P = .032, OR = 0.11, CI: 0.02-0.83). Systemic aGVHD-related lesions were common in all patients. The prevalence of opportunistic oral infections was not statistically different between the NST and ablative groups (P = .94). Conclusions: In this pilot study, cancer patients treated with NST had a lower incidence of oral aGVHD than those receiving myeloablative HSCT. The incidence of other oral soft tissue lesions, including opportunistic infections, was not affected by the type of HSCT. Keywords: GVHD, hematopoietic stem cell transplantation, infection, myeloablative, oral

A case is presented of a 14-year-old boy with aneurysmal bone cyst of the tuberculum articulare of the temporomandibular joint (TMJ). This disease rarely involves the skull, and involvement of temporal bone is even more rare. To our knowledge, only 22 cases have been reported in the literature. This is the first case of aneurysmal bone cyst of the tuberculum articulare of the TMJ described in the literature. Keywords: aneurysmal bone cyst, temporal bone, temporomandibular joint, tuberculum articulare

Objectives: To evaluate (1) the apical seal of root-end cavities using mineral trioxide aggregate (MTA) and glass-ionomer cement in teeth with and without cracks after ultrasonic root-end preparation and (2) the obturation efficiency of the materials in the root-end cavities. Method and Materials: Sixty teeth with root-end cavities were divided into 3 groups: teeth without cracks (-) (group A) and teeth with cracks (+) (group B). The third group (4 teeth) served as a control. Groups A and B were each divided into 2 subgroups: Groups 1A and 1B were filled with Fuji IX capsules (GC) after treatment with cavity conditioner; groups 2A and 2B were filled with white MTA (Dentsply). The teeth were immersed in india ink and cleared. Apical leakage was measured from the resection surface to the maximal point of ink infiltration. Obturation efficiency was scored as good (acceptable), irregular (acceptable), or poor (unacceptable). Statistical analysis was performed using nonparametric and Fisher exact tests. Results: Apical leakage could be arranged in the following order: Fuji IX+ > MTA+ > Fuji IX- > MTA-. Significant differences between Fuji IX- and Fuji IX+ (P < .001) and between MTA- and MTA+ (P < .001) were demonstrated. Fuji IX showed significantly more unacceptable fillings than did MTA (P < .005). No correlation between obturation efficiency and apical leakage was demonstrated (P > .05). Conclusion: The presence of cracks originating from the root canal negatively influences the seal of root-end filling materials and is probably of major clinical importance. MTA and Fuji IX showed equal sealing capacity, but MTA showed better obturation efficiency in the root-end cavity than Fuji IX. Keywords: crack, Fuji IX, glass-ionomer cement, leakage, MTA, obturation, periradicular surgery, root-end filling, seal

The adenomatoid odontogenic tumor is an unusual lesion that usually presents in the anterior maxilla. In contrast, the odontoma is the most common odontogenic tumor. The concurrent occurrence of these tumors in a single lesion is extremely rare. Such a lesion occurred in the mandibular canine region of a 13-year-old boy. While the hard tissue component of the lesion consisted of irregularly organized enamel and dentin matrix, the soft tissue component was composed of loosely arranged spindle cells and whorled masses of cells. Ductlike structures were observed around eosinophilic matrix. The histopathologic findings were consistent with concurrent occurrence of an odontoma and adenomatoid odontogenic tumor. Keywords: adenomatoid odontogenic tumor, ectomesenchyme, odontogenic epithelium, odontoma

The accidental displacement of foreign bodies into the maxillary sinus is not an unusual complication in dental clinical practice. However, dental materials, and, in particular, dental impression materials, introduced into the sinus several weeks to months after a maxillary tooth extraction or dentoalveolar surgery through either a small, long-standing oroantral fistula or an insufficiently healed extraction wound is uncommon. In the case reported, 3 months after a maxillary molar extraction, the material used for maxillary impression was pushed into the antrum through a small, almost invisible, oroantral fistula that was unseen by the specialists the patient had been visiting, worsening the patient's existing sinusitis. Keywords: foreign body, impression material, maxillary sinus

Objective: Endodontically treated maxillary first premolars present a restorative challenge. The objective of the present study was to assess the resistance to fracture of crowned endodontically treated maxillary first premolars under simulated occlusal load, while preserving various degrees of remaining coronal structure. Methods and Materials: The study consisted of 50 intact maxillary first premolars with bifurcated roots and similar root diameter and length, randomly divided into 5 equal experimental groups. All dowels were luted with Flexi-Flow titanium-reinforced composite resin cement. TiCore titanium-reinforced composite resin was used to fabricate the core. Complete cast crowns were fabricated and cemented with zinc phosphate cement. Forces at fracture and mode of failure were recorded. Results: Statistically significant differences (P < .05) were found among mean failure forces for all tested groups in their resistance to fracture under load with the Kruskal-Wallias test and among all combinations of the 5 groups (Z = -1.56/ -2.34; P > .05) with the Mann-Whitney test. This indicates that crowned maxillary first premolars with varying degrees of remaining coronal structure differ significantly in their resistance to fracture under occlusal load. There was increased protection against fracture under occlusal loads with more remaining tooth structure. Conclusions: Within the limitations of this study, remaining coronal structure influenced the fracture resistance of crowned endodontically treated maxillary first premolars. Preservation of tooth structure is important for its protection against fracture under occlusal loads and may influence the tooth prognosis. Keywords: maxillary first premolar, resistance to fracture

Objective: To examine the influence of a reduced post length sealed with a titanium-reinforced composite luting agent on the fracture resistance of crowned endodontically treated teeth with a 2-mm ferrule on healthy tooth structure. Method and Materials: The study consisted of 60 intact single-rooted premolars with similar root diameters and lengths. Teeth were endodontically treated and randomly divided into 6 experimental groups (n = 10) with various post lengths (5, 8, and 10 mm) and types (ParaPost and Dentatus) of equal diameter. Posts were luted with a titanium-reinforced composite resin luting agent. Titanium-reinforced composite resin cores were constructed, and cast crowns with a 2-mm ferrule on healthy tooth structure were cemented. Specimens were mounted in a jig that allowed loading of the buccal cusp in the axio-occlusal line at a 30-degree angle to the long tooth axis. A continuous compressive force at a crosshead speed of 2 mm/min was applied by an Instron testing machine. Forces at fracture (in newtons) and mode of failure were recorded. One-way analysis of variance (ANOVA) and the Scheffé test were used to statistically compare the differences among groups at a significance of 5%. Results: ANOVA showed no statistically significant differences among the mean failure forces for the tested groups in their resistance to fracture under load. The Scheffé contrast test showed no statistically significant differences among all combinations of the 6 tested groups (F [5.59] = 0.032; P > .05). Conclusion: Within the limitations of this study, post length did not influence the fracture resistance of crowned endodontically treated teeth with a 2-mm ferrule on healthy tooth structure. For tooth resistance, prosthesis design is more important than post characteristics. Keywords: post length, resistance to fracture