The aesthetic composite anterior single crown restoration

Achieving natural aesthetics by harmoniously matching the shape and color of a single anterior crown is perhaps one of the greatest challenges in restorative dentistry. The clinician must often rely on the artistic skills of a laboratory technician who has no direct access to the patient. The shade selection process is, therefore, impaired, and the final result may be a restoration which does not emulate the aesthetics of the adjacent natural dentition. The learning objective of this article is to present an innovative technique which utilizes the qualities of high strength laboratory processing in association with the application of light curing and freehand bonding of composite resins. This combination allows the clinician to predictably achieve aesthetic results with single anterior crowns. The direct, indirect, and indirect/direct restorations are discussed, and the laboratory and clinical procedures are reviewed.     

The restoration of destroyed crowns of the anterior teeth with combined inlays]

An original design of a microdenture insert is suggested, as are methods of preparing it to restore the frontal teeth after an injury not involving the pulp. The insert consists of two elements permitting disposition of the parapulpar pins at an almost right angle, providing a reliable fixation of the insert on the tooth. Clinical follow-up of 25 patients with 27 inserts for up to 3 years demonstrated the efficacy of such treatment.     

Trans-surgical restoration of extensive Class IV defects in the anterior dentition

Direct bonding is the most commonly utilized treatment for conservative aesthetic restoration of the anterior dentition. Class IV defects require special attention due to their high incidence, particularly in young patients. One of the major challenges for the clinician in treating defects in this category is selecting the appropriate restorative composite resin material that emulates the physical and optical characteristics of dentin and enamel and conceal the fracture line at the tooth/composite interface. Class IV defects with margins violating the biologic width present another concern, since this violation often impedes the attainment of the correct anatomic contours. The learning objective of this article is to describe a technique for achieving a correct integration of the periodontium, the tooth structure, and the restorative composite resin material to achieve a high level of aesthetic excellence.     

A review of esthetic alternatives for the restoration of anterior teeth

Helicobacter pylori infection is an important cause of peptic ulcer disease and chronic gastritis. Infection with this bacterium stimulates the production of immunoglobulin (Ig) G antibody. Salivary IgG antibody tests to detect H pylori infection offer a convenient and noninvasive method of diagnosis. To evaluate an IgG salivary antibody kit, saliva was collected from 157 out-patients with dyspepsia referred for endoscopy to a tertiary centre. A salivary IgG ELISA antibody assay was performed using the Helisal Helicobacter pylori (IgG) assay kit, and at least four gastric biopsies were obtained. H pylori infection was confirmed by demonstration of the organism on Warthin-Starry silver stain (sensitivity 85%, specificity 55%). The prevalence of infection with H pylori was 30%. When the analysis was redone, excluding those treated with eradication therapy, the results were similar (sensitivity 86%, specificity 58%). The positive predictive value of the assay was 45% and the negative predictive value was 90%. Despite the ease of sampling, the assay used has limited diagnostic utility, lacking the predictive value to indicate which patients referred with dyspeptic symptoms to a tertiary care setting are infected with H pylori.     

The use of resin-bonded porcelain crowns for primary molars in infra-occlusion

Infra-occluded primary molars without permanent successors may require restorative treatment to maintain occlusal stability and periodontal health in addition to creating an aesthetic result. This paper describes the use of two resin-bonded porcelain crowns to provide a simple, minimally invasive technique using a material with good wear resistance and high strength to create an aesthetic and functional occlusion.     

Tooth fragment reattachment: an alternative for restoration of fractured anterior teeth

The development of advanced adhesive systems has made it possible to bond various substrates, e.g., composite resin and vital or nonvital tooth structures. The management of coronal and coronoradicular fractures in the maxillary region with these adhesive materials is easier, safer, and more efficacious than the use of traditional treatment alternatives that involve the use of posts and cores and/or other mechanical devices to obtain retention. Ability to bond the dislocated segment of the fractured tooth constitutes a significant step forward in the management of this clinical condition.     

A method for preparing the abutment teeth for resin-bonded bridge dentures and resin-bonded facings (veneers) and its anatomical validation

This article describes a relatively new modality of tooth preparation techniques used in Maryland bridges and veneers. Tooth preparation based on enamel thickness data is routinely recommended.     

Marginal adaptation of resin-bonded light-cured glass ionomers in dentin cavities

PURPOSE: To investigate the marginal adaptation of resin-modified glass ionomer cements in dentin cavities placed with or without additional application of resin bonding systems. MATERIALS AND METHODS: Three resin-modified materials (Fuji II LC, Photac-Fil, Vitremer), one compomer (Dyract) and as reference an adhesively bonded resin composite system (Gluma CPS-Pekafill) were used. Flat peripheral dentin surfaces on human molar teeth were produced by wet grinding on SiC paper. Cylindrical cavities, 3.5 mm wide, were prepared in these dentin areas and restored with the individual materials. Sixty cavities were pretreated and restored as requested by the respective manufacturers. Following water storage of the specimens for 15 minutes or 24 hours, excess was gently removed by wet grinding for microscopic inspection of the marginal area. Additionally, in 30 cavities an experimental one-component adhesive resin system, a proprietary dimethacrylate and HEMA mixture dissolved in acetone, was combined with each of the restoratives for evaluation after 15-minutes water storage. Finally, in six cavities each, Dyract was combined with Prime and Bond 2.0, and Vitremer with Scotchbond Multi-Purpose Plus for assessment after 15 minutes. Maximum marginal gap widths (MGW) were measured. One-way ANOVA by ranks (Kruskal-Wallis-Test) followed by Wilcoxon's Two-Sample test were used to study the statistical difference of MGW among the treatment groups at a rejection level P = 0.05. RESULTS: Neither the conventionally placed material systems nor the restorations in combination with adhesives showed consistently gap-free margins after 15-minute water storage. After 24-hour storage with Vitremer 4 of the 6 restorations were gap-free, whereas with all other materials only perfect margins were registered. There was, however, no significant difference between the groups. Application of the experimental and/or the specific resin bonding agents had no effect on early MGW except for the Photac-Fil group, which was significantly reduced.     

A laboratory evaluation of the construction of resin-bonded cast restorations

OBJECTIVE: To compare the effect of two construction techniques and two pattern materials on the fit of resin-bonded cast restorations. DESIGN: In-vitro study carried out by one operator. SETTING: Postgraduate university hospital. SUBJECTS AND METHODS: 65 nickel-chrome castings were constructed using refractory die and lift-off techniques with wax and acrylic resin pattern material. They were cemented onto master silver dies, embedded in self-curing acrylic resin and sectioned along their long axes. Interfacial distance between the master silver die and casting was measured. RESULTS: A significant different between the range of figures in each group (Mann-Whitney Test, P < 0.01) was found. Construction techniques can be ranked in order of fit of castings: 1. Refractory die, wax patterns: 42.6 microns (SD 12.03). 2. Refractory die, acrylic resin patterns: 53.7 microns (SD.16.06).3. Conventional technique, acrylic resin patterns: 85.5 microns (SD 31.62). 4. Lift-off technique, wax patterns: 139 microns (SD 53.15).5. Lift-off technique, acrylic patterns: 172.8 microns (SD 74.04). CONCLUSIONS: Castings constructed using refractory die technique and subsequently cemented resulted in a more accurate and less variable fit than those produced with the lift-off technique. Wax patterns lead to more accurate castings than acrylic resin and locating indentations may interfere with the cementation of castings when lift-off techniques are used.     

The traumatic anterior overbite

The position of the anterior teeth and skeletal base relationship establish many of our facial characteristics, yet these same tooth positions can result in a range of dental problems that are often specific for a particular incisal relationship. Excessive loss of tooth tissue on various surfaces may result in trauma to the soft tissue and temporomandibular joint dysfunction. A range of treatment options may be required and can often be conveniently classified by the form of incisal relationship.     

The falling anterior labrum

Two cases of a falling anterior glenoid labrum are presented. The anterior labrum appears normal on supine double contrast computed tomographic arthrography (DCCTA). However, on prone DCCTA the anterior labrum falls away from the glenoid. The addition of prone DCCTA in these two cases reveals a labral tear, occult on routine supine DCCTA.     

高炉树脂结合硬质压入修补料的研究

对改性树脂结合的高炉硬质压入修补料的组成、性能进行了研究,探讨了不同组成对性能的影响关系,研制的新型压入修补料高温下流动性好,粘结强度高,使用性能良好.     

修复热处理方法及技术内涵分析

具体分析了修复热处理的技术内涵及应用途径．并对修复热处理的目的及内容进行了概述;重点讨论了材料失效机理和作为修复热处理基本原理的材料自愈合和自修复机理,并对修复热处理的基本方法和应用进行了简单介绍。     

The normal anterior commissure of the glottis

OBJECTIVE: We characterized the normal width of the anterior commissure of the glottis by measuring its dimensions on CT scans obtained in patients who had no laryngeal disorders. SUBJECTS AND METHODS: CT scans of patients referred for cervical CT myelography were prospectively reviewed by a single board-certified radiologist. Axial images through the anterior commissure (localized by vocal process of the arytenoid cartilage, the vocal muscle, or both) were magnified on the viewing console of the CT scanner. Window and level were chosen to simulate our routine settings for CT scans of the neck. Anteroposterior width of the anterior commissure was measured using an electronic ruler with 1-mm marks. RESULTS: Sixty-five patients were prospectively evaluated. Nine patients were excluded because of substantial motion artifact, and another 18 were excluded because CT images did not include the entire larynx. Thus, the final study group included 38 patients. The average width of the anterior commissure was 1.02 +/- 0.56 mm. The width was less than or equal to 1.1 mm in 22 (58%) of 38 patients. The width was less than or equal to 1.7 mm in 35 (92%) of 38 patients. Forty-two percent (16 of 38 patients) had anterior commissures wider than 1.0 mm. The maximum width of 2.2 mm was seen in only one patient. CONCLUSION: The mean width of the anterior commissure was approximately 1.0 mm. However, 42% of patients had anterior commissures wider than 1.0 mm. In our series, using an upper limit of 1.6 mm as a normal measurement for the anterior commissure would have included 92% of patients, and an upper limit of 2.1 mm would have encompassed the mean plus two SDs.     

The full coverage restoration in relation to the gingival sulcus

The full coverage restoration (FCR) and its effect on the periodontium have been the subject of much controversy over the last half century. The conflict relates to whether the margin of the FCR should be placed at or above the gingival crest, or into the gingival crevice. Clinicians and researchers alike have focused their attention primarily on the mechanistic aspects of fixed prosthetic design (i.e., marginal configuration and fit). Although marginal quality and form are factors in the fabrication of the FCR, they alone will not determine periodontal health and restorative success. What determines the success of the FCR is its ability to restore form and function to the masticatory system without adversely affecting its biology. Each technical phase of treatment (i.e., tooth preparation, impression-taking, the provisional restoration, and the final restoration) must be performed within the limits of biologic adaptation. This literature review discusses the scientific evidence regarding FCR margin placement and periodontal health.     

The implant-supported single-tooth restoration. Preoperative evaluation and clinical procedure

The implant-supported restoration is a relatively new and promising treatment modality. The CeraOne system offers a complete set of easy-to-use prosthetic components plus the all-ceramic and ceramometal restorative alternatives. No clinical signs of loosening have been reported since the adjunct of a torque controller that provides a tightening force of 32 Ncm to the abutment gold fixation screw. Even with these developments, however, a meticulous presurgical evaluation of the periodontium and careful fixture placement are still imperative for a successful esthetic and functional result.