Vertical mammaplasty as secondary surgery after other techniques

The effect of ultrasonic insertion on the filler content and the gap width for two brands of composite resin luting agents, intended for luting with the ultrasonic insertion technique, were studied after MOD ceramic inlays (Cerec) had been placed. In addition, the internal and marginal gap widths were determined after MOD ceramic inlays (Celay) bad been luted on extracted premolars with this technique. No statistically significant differences (P > 0.05) were observed for either brand between the filler content obtained from the internal surfaces, from the excess luting agent, or from the luting agent as delivered. There were no statistically significant differences (P > 0.05) between the final internal and marginal gap widths when the two brands of luting agent were compared with each other. Except for the final occlusal and internal gap widths obtained for the inlays luted with the Sono-Cem luting agent, no statistically significant differences (P > 0.05) were observed between the gap widths at the different locations determined. Thus, the ultrasonic insertion technique used did not significantly influence the filler ratio of the hybrid luting agents studied. Judged by the findings in this study, the properties of luting agents seem to greatly influence the final marginal and internal gap widths.     

Histological changes induced by CO2 laser microprobe specially designed for root canal sterilization: in vivo study

Sixty-six class-II CAD/CAM-manufactured ceramic inlays (Cerec) were placed in 27 patients. Each patient received at least one inlay luted with a dual-cured resin composite and one inlay luted with a chemically cured resin composite. The inlays were examined 5 years after luting using the California Dental Association (CDA) criteria. Eighty-nine percent of the 66 inlays were rated 'satisfactory'. During the follow-up period replacement was required for 3 inlays because of inlay fractures (4.5%) and 1 inlay because of fracture of the tooth substance (1.5%). All those inlays were luted with the dual-cured resin composite luting agent. Of the remaining 62 inlays the CDA rating 'excellent' was given to 84% for color, 97% for surface, and 81% for anatomic form. 'Excellent' margin integrity was seen in 52% of the dual-cured resin composite luted inlays and in 61% of the chemically cured resin composite luted inlays. No statistically significant (P> 0.05) difference was observed between the two luting agents.     

Resin-modified glass ionomers for luting posterior ceramic restorations

OBJECTIVES: Until recently, esthetic inlay restorations in posterior teeth have been limited to cavities surrounded by enamel. Dentin adhesive systems in combination with luting composites and light-cured resin-modified glass ionomer cements offer a possibility for bonding ceramic inlays to cavities when the cervical margin is in dentin. This study was designed to compare in vitro marginal integrity of ceramic inlays bonded to dentin to restorations placed in cavities with margins located entirely in the enamel. METHODS: In the present in vitro study, the sealing abilities of a dentin bonding agent/luting composite combination (Syntac/Dual Cement, Vivadent) and resin-modified glass ionomers (Photac Fil, Photac Bond, ESPE; Dyract, De Trey Dentsply; Fuji II LC, GC Dental Industrial Corp.; and Vitremer, 3M Dental Products) used as luting agents in cavities extending beyond the cemento-enamel junction, were compared to the sealing abilities of a conventional luting composite (Vita Cerec Duo Cement, Vita) in cavities within sound enamel. SEM analysis and dye penetration were performed to evaluate marginal integrity at the cervical cavity margins. RESULTS: The dentin bonding agent/luting composite combination (Syntac/Dual Cement) rendered a marginal seal within the dentin similar to the quality obtained with the conventional luting procedures within sound enamel. When three out of the five resin-modified glass ionomers were used as luting agents (Dyract, Fuji II LC and Vitremer), the results were comparable to those reported for the dentin bonding agents and the conventional method. SIGNIFICANCE: Light-cured resin-modified glass ionomer cements may be considered as an alternative to dentin bonding agents when the cavity margins of ceramic inlay restorations are within the dentin. However, further studies, e.g., wear resistance, must be performed.     

Comparison of marginal fit and microleakage of ceramic and composite inlays: an in vitro study

The purpose of this in vitro study was to evaluate the marginal fit and microleakage of four types of ceramic or resin composite inlays. Sixty extracted human third molar teeth were randomly assigned into four groups. MOD cavities without bevels were prepared. The mesiogingival margin was cut in enamel, whereas the distogingival margin was placed below the amelocemental junction. The preparations and inlays were made according to the manufacturers' instructions. After acid-etching and treatment with a dentine bonding agent the inlays were cemented with dual curing CEREC resin composite luting material. After placement and polishing 10 teeth of each group were thermocycled 2500 times between 14 degrees C and 62 degrees C. Each tooth was bisectioned and from each part, one occlusal and three proximal sections of 75-100 microns thickness were cut and ground (EXAKT Cutting and Grinding system). The marginal discrepancy and the thickness of the luting cement were measured microscopically at each section and an average for each tooth was calculated. Considerable variation of marginal fit was seen, within inlays, and among different types of inlays. In general, the Vita Dur N inlays showed the best fit, e.g. the thickness of the luting cement for Vita Dur N was 114 microns occlusally and 119 microns mesiogingivally compared to 199 microns occlusally for CEREC and 219 microns mesiogingivally for Estilux. At enamel margins, a tendency of less microleakage was seen for ceramic inlays compared to composite inlays.     

Long term clinical evaluation of three luting materials

A last critical step in the completion of a cast restoration is permanent cementation. With the development of new luting agents the practitioner has to be aware of the physical and biological properties as well as the long term clinical performance of these materials. In this study three commonly used luting agents were evaluated over a four year period. The three cements, a zinc phosphate, a glass ionomer and a resin cement were tested for their reaction to periodontal tissues, pulpal response and other clinical parameters. In twenty six patients, 61 crowns, onlays or bridge abutments were cemented. Evaluations were made at 0 hour, after 7 days, 6 and 12 months and 4 years. In general the cements performed satisfactorily. Health of periodontal tissues adjacent to the crowns improved considerably after 7 days. Postcementation hypersensitivity appeared to be a negligible problem, which was attributed to the time span between preparation and cementation, which exceeded in most instances four weeks. The choice of a final luting agent should be based on anticipated postoperative pulpal reactions, rather than exclusive reliance on physical properties.     

Wear resistance of four luting agents as a function of marginal gap distance, cement type, and restorative material

This study investigated the effect of marginal gap width, luting cement, and restorative material on the wear resistance of the luting cement in areas where no occlusal contact is present. Three types of resin luting cement and one resin-modified glass-ionomer cement were used with two inlay systems, a resin composite, and an all-ceramic system. Bovine enamel represented tooth structure. Toothbrush abrasion was the wear modality. Three predetermined gap widths were selected: 240 +/- 30 microns, 150 +/- 30 microns, and 60 +/- 30 microns. All specimens were thermocycled. Regardless of the luting cement or the restorative material, there was a significant difference (P < 0.05) in wear resistance of the cement among the three gap distances at both the enamel and restoration interface. Vertical wear of the luting cement at the enamel interface increased linearly with marginal gap distance when all four cements were considered together (r2 > 0.51), regardless of type of restorative material used. The resin-modified glass-ionomer cement showed the least amount of wear for all variables considered. Significant differences in wear were found between the four luting cements at wide gap distances (240 microns) at the enamel interface, regardless of type of restorative material used. No significant differences were found between the two restorative materials at the enamel interface at the three gap distances.     

Indirect composite restorations in the anterior region: a predictable technique for complex cases

The indirect composite inlay technique demonstrates excellent aesthetic results in the posterior regions, achieved by reproducing the shape, color, and contour of the natural tooth on a cast model rather than using the free-hand composite restorative modality. The utilization of the indirect technique can be adapted for the anterior regions as well, and it offers a valid treatment alternative that is predictable with optimal restorative results. The evaluation, planning, and accuracy of implementation of the various phases of this methodology allow a more precise achievement of the result; any potential error in the restoration can be corrected prior to final cementation. This technique increases the quality of composite restorations that have always been considered unpredictable and extensively dependent upon the skills of the operator. The learning objective of this article is to familiarize the reader with the clinical and laboratory phases of this indirect treatment modality of the anterior dentition.     

Use of 2-isocyanatoethyl methacrylate and iron (II) perchlorate for bonding tri-n-butylborane-initiated luting agents to dentin

The present study investigated the effect of 2-isocyanatoethyl methacrylate (IEM) and iron (II) perchlorate on dentin adhesion. Four primers were evaluated, consisting of aqueous 2-hydroxyethyl methacrylate (HEMA) solutions containing 5, 10, 20 or 50 micromol/g iron (II) perchlorate. Five luting agents were prepared with methyl methacrylate (MMA), poly(methyl methacrylate) (PMMA), tri-n-butylborane (TBB) initiator and IEM. The concentrations of IEM in the luting agents were 0.2, 0.4, 0.8, 2.0 and 4.0 wt%. Extracted bovine teeth were ground to expose the dentin, etched with an aqueous solution of 10 wt% phosphoric acid, primed, and then bonded with stainless-steel rods; tensile bond strengths were determined after 1 d immersion in water. The highest bond strength (20.7 MPa) was recorded for the group using 10 micromol/g iron (II) perchlorate and 2.0 wt% IEM. The use of IEM was effective in decreasing the optimal concentration of iron (II) perchlorate, and this may contribute to the color stability of iron-containing pretreatment agents.     

Retentive properties of a threaded split post with attachment sleeves cemented with various luting agents

This study determined the retention, in pounds, of Nos. 1 through 3 stainless steel attachment sleeves for the threaded split post system cemented with various cements. Post heads and matching sleeves were also sandblasted and compared with attachments not sandblasted. Four luting agents were selected, zinc oxyphosphate cement (ZOP), and three brands of composite resin cement (CRC). The experiment was divided into two parts; in part 1, samples were not treated, and in part 2, samples were sandblasted. Retentive values were recorded with a universal testing machine. A 2 x 3 x 4 factorial three-way analysis of variance was used to compute the effects sandblasting, sleeve and post type, and the luting agent. No statistical differences were recorded for sleeves not sandblasted, Nos. 1 and 2, regardless of the luting agent. The nonsandblasted No. 3 sleeve cemented with Panavia CRC had significantly greater retention than All-Bond CRC or ZOP. There were no statistical differences in retention of sandblasted sleeves for the No. 1 sleeve despite the type of luting agent. For sandblasted sleeves Nos. 2 and 3, ZOP and Panavia CRC recorded significantly greater retention than All-Bond CRC. However, there was no difference between sandblasting and not sandblasting for the No. 1 sleeve. Mean loads for Nos. 2 and 3 sleeves were substantially greater for sandblasted compared with attachments not sandblasted.     

Evaluating interfacial gaps for esthetic inlays

Because of some inadequacies associated with the direct fill posterior composite resin, the inlay/onlay form of the same material or ceramic agents has been introduced. This clinical investigation measured the wear rate of several types of luting agents with both resin and ceramic restorative systems and identified several factors related to wear of the cementing agent.     

Stability of radicals in cured composite materials

During the radical polymerization of dental composites, the monomers polymerize to form a three-dimensional network containing remaining double bonds and free radicals. At 37 degrees C, these radicals decompose logarithmically with a half-life of 2-5 d. In this study, the half-life of radicals in a light-cured inlay composite was determined at different temperatures, and the influence of different fillers and filler amounts on the stability of these radicals in light-cured experimental composites was investigated. There is a strong logarithmic relationship between the half-life of the radicals and temperature. At a constant temperature, the half-life of radicals depends on the type of filler, the filler fraction, and the filler surface treatment. The stability of radicals determines to a great extend the adhesion of one composite to another, such as the adhesion of a luting cement to an inlay material.     

Corrected master cast procedure for intraoral luted implant frameworks

Large cast frameworks rarely fit multiple implant abutments passively without time-consuming labor-intensive adjustment procedures. Intraoral luting of components has been suggested to achieve a passive fit and eliminate most adjustment procedures. When the intraoral luted framework is returned to the master cast, the implant analogs may not be properly aligned to framework abutments. To complete the restoration, master cast modification or replacement may be required. The procedure described in this article produces a corrected master cast that fits the final framework and preserves the tissue topography of the original master cast.     

Adhesive crowns and fixed partial dentures fabricated of ceromer/FRC: clinical and laboratory procedures

Ceramic optimized polymer and fiber-reinforced composite materials represent a significant development in prosthetic dentistry. When utilized in conjunction with adhesive luting techniques, exceptionally conservative crown and bridge restorations may be achieved. This article discusses utilization of these materials in inlay and onlay restorations, as well as clinical and laboratory procedures for fabrication, preparation, and seating of adhesive crown and bridge restorations. The initial results of restorations utilizing these innovative materials are presented.     

An investigation of hot corrosion morphology by color X-ray distribution imaging

The structure of corrosion layers on nickel-base alloys resulting from reaction with sulfur dioxide and sodium sulfate at elevated temperatures (hot corrosion) has been studied by the method of color X-ray distribution imaging. This technique involves the preparation of color composite prints by superimposing primary color images of the individual element X-ray distributions on a single sheet of color film. By a proper choise of primary tints, the distribution of reaction products and other features of thé corrosion morphology can be clearly defined as a result of color mixing in the composite micrograph. The distribution of corrosion products in the surface layers of Ni-Cr and Ni-Al alloys and an IN 738 specimen following sulfidation was investigated using this technique.     

An investigation of hot corrosion morphology by color X-ray distribution imaging

The structure of corrosion layers on nickel-base alloys resulting from reaction with sulfur dioxide and sodium sulfate at elevated temperatures (hot corrosion) has been studied by the method of color X-ray distribution imaging. This technique involves the preparation of color composite prints by superimposing primary color images of the individual element X-ray distributions on a single sheet of color film. By a proper choise of primary tints, the distribution of reaction products and other features of thé corrosion morphology can be clearly defined as a result of color mixing in the composite micrograph. The distribution of corrosion products in the surface layers of Ni-Cr and Ni-Al alloys and an IN 738 specimen following sulfidation was investigated using this technique.     

A new approach in restorative treatment of external root resorption. A case report

This case report describes the treatment of an external root resorption with extensive loss of tooth structure and bone at the labial surface of an upper left central incisor. The area of bone loss and root resorption was surgically exposed and an impression was taken using curing silicone. An individual ceramic insert was fabricated, allowing endodontic retreatment through an artificial root canal. The insert was incorporated using a dentin bonding system and a dual curing luting composite. Following endodontic retreatment and internal bleaching, a ceramic veneer was bonded to the tooth to obtain good esthetics and to improve stability. Twenty months after surgical treatment no further root resorption could be detected radiographically. A shallow residual pocket but no bleeding on probing was found.     

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.     

Masking severely tetracycline-stained teeth with ceramic laminate veneers

When the primary restorative objective is the reinstatement of vital natural tooth color, dark tetracycline-stained teeth still represent the ultimate challenge for ceramic laminate veneers. Masking severe stain with opaquing composite resins is a significant advancement; however, the procedure requires additional chairtime, is technique sensitive (to avoid excessive opacity), and involves removal of additional tooth structure. The learning objective of this article is to describe and compare two different methods for masking tetracycline-stained teeth. The article illustrates the natural tooth color derived from ceramic laminate veneers when bonded to opaque composite resins in the maxillary arch, and compares it to a new ceramic veneer formulation in the mandibular arch, which masks the stain, eliminates the need for subopaquing with composite resins, and resembles the qualities of natural tooth color.     

Current status of luting agents for fixed prosthodontics

STATEMENT OF THE PROBLEM: The long-term clinical outcome of fixed prosthodontic treatment depends, in part, on the use of adhesives that can provide an impervious seal between the restoration and the tooth. There are several types of available luting agents, each possessing unique properties and handling characteristics. No one product is ideal for every type of restoration. PURPOSE: The purpose of this article is to review available dental luting agents, discuss improvements and drawbacks in newly formulated adhesives, and present the indications for their use. RESULTS: Each cement type is physically and chemically unique. A single adhesive will not suffice in modern day clinical practice.     

The effect of adhesive luting agent-dentinal surface interactions on compressive strength of two types of all-ceramic crowns

This research compared the compressive strength of two types of all-ceramic crown (Hi-Ceram and Duceram) as affected by selected luting cements (Zn phosphate, glass ionomer and composite resin cement). Thirty crowns of similar size and shape were constructed (15 crowns of each tested material) to fit a standard posterior tooth preparation. Five crowns from each material were cemented by one of the tested cements. The cemented crowns were loaded until catastrophic failure. A two-way analysis of variance was performed and showed that the type of utilized cement had a significant effect on the compressive strength being that Panevia Ex. resin cement the most effective one followed by glass ionomer and then finally zn phosphate cement. Statistical analysis also showed that Hi-Ceram crowns were more resistant to occlusal load than Duceram.