Despite all--do we have an appropriate substitute for amalgam?

The ultimate success or failure of a restored tooth is largely dependent on clinical management. Clinicians may choose from a number of restorative materials, different clinical techniques and cavity preparation procedures. Composite resin has been used for nearly 50 years as a restorative material in dentistry. The use of this material has recently increased as a result of patients' demands for esthetic restorations. Failure of dental restorations is a major concern in dental practice. Replacement of failed restorations constitutes the majority of operative work. Clinicians should be aware of the longevity of, and likely reasons for the failure of, direct posterior restorations. Higher failure rates were observed in resin-based composite restorations as compares amalgam restorations. Secondary caries was the main reason for failure. Posterior interproximal resin-based composite restorations should be considered with caution, and their limited long-term performance should be kept in mind. Patients should be informed about the potential longevity of restorative treatment for posterior teeth as they make decisions about treatment for their oral restorative needs.     

Sorting out the confusing array of resin-based composites in dentistry

Several categories of useful restorative resin-based composites have evolved over the past 40 years. Some of them are indispensable; others are clearly not as necessary. It is possible that dental practitioners could practice successfully with only one type of resin-based composite: hybrid. But each type added to a clinical armamentarium provides possibilities for better esthetic results, easier and better clinical placement, or better long-term function. Undoubtedly, even more categories of restorative resin-based composite will evolve in the future. Dentists are advised to observe them carefully before buying to see if they satisfy any additional needs.     

Ceramic inlays and onlays: clinical procedures for predictable results

The use of ceramics as restorative materials has increased substantially in the past two decades. This trend can be attributed to the greater interest of patients and dentists in this esthetic and long-lasting material, and to the ability to effectively bond metal-free ceramic restorations to tooth structure using acid-etch techniques and adhesive cements. The purpose of this article is to review the pertinent literature on ceramic systems, direct internal buildup materials, and adhesive cements. Current clinical procedures for the planning, preparation, impression, and bonding of ceramic inlays and onlays are also briefly reviewed. A representative clinical case is presented, illustrating the technique.
CLINICAL SIGNIFICANCE
When posterior teeth are weakened owing to the need for wide cavity preparations, the success of direct resin-based composites is compromised. In these clinical situations, ceramic inlays/onlays can be used to achieve esthetic, durable, and biologically compatible posterior restorations.     

Combined amalgam and composite restorations

All indirect restorative techniques involving cast metals, ceramics or resin-based materials are expensive compared to directly placed restorations. A restorative technique is presented that combines the esthetic properties of directly bonded resin-based composite material and the wide range of indications for dental amalgam in stress-bearing areas.     

The use of dental amalgam in pediatric dentistry: review of the literature

Dental amalgam is widely used as a restorative material even though it is not esthetic and there has been extensive anti-amalgam rhetoric. Although other materials have improved greatly, amalgam has the proven safety record and best cost-to-benefit ratio. Clinical evidence indicates that, in the posterior permanent dentition--where esthetics is not a primary concern--the small, minimally prepared, amalgam restoration, with its margins and any caries-susceptible fissures sealed with resin fissure sealant, is the restoration with the best survival. Amalgam also remains the best direct restorative option when larger restorations are required. In the primary dentition, the data indicates that resin-based composite and resin-modified glass-ionomer serve very well.     

The physical properties of packable and conventional posterior resin-based composites: a comparison

BACKGROUND: The authors compared the physical properties of three packable hybrid resin-based composites with those of a conventional hybrid and a microfill composite material advocated for use as posterior restorative materials. They evaluated diametral tensile strength, or DTS; compressive strength, or CS; flexural strength, or FS; and depth of cure, or DC. METHODS: The authors studied the following resin-based restorative materials: three packable composites, Alert Condensable Composite (Jeneric Pentron), SureFil High Density Posterior Restorative (Dentsply Caulk) and Solitaire (Heraeus Kulzer); one conventional hybrid composite, TPH Spectrum (Dentsply Caulk); and one microfill, Heliomolar Radiopaque (Ivoclar-Vivadent). The authors evaluated DTS, CS, FS and DC, according to American National Standards Institute criteria. They made scanning electron micrographs of the packable resin-based composites. RESULTS: Results demonstrated that the conventional hybrid, TPH Spectrum, had significantly greater DTS and FS than other resin-based composites. Alert and SureFil had comparable DTS and FS, which were significantly greater than Heliomolar's DTS and FS. Solitaire had significantly lower DTS and FS than all other resin-based composites. SureFil had the highest CS, followed by TPH Spectrum, Solitaire and Alert, which were comparable and had significantly greater CS than Heliomolar. TPH Spectrum and Alert had significantly greater DC than all other resin-based composites, followed in decreasing order by SureFil, Solitaire and Heliomolar. CONCLUSION: While the packable composites tested in this study had physical properties superior to those of the microfill composite, they were no better suited for use as a posterior restorative material than was the conventional hybrid resin-based composite. CLINICAL IMPLICATIONS: Packable composites may be easier for clinicians to handle than conventional resin-based composites; however, their physical properties were not superior to those of the conventional small-particle hybrid resin-based composite. In addition, these materials may have the clinical drawback of increased wear and surface roughness that was seen with early, large-particle composite restorative materials.     

An alternative method to reduce polymerization shrinkage in direct posterior composite restorations

BACKGROUND: Polymerization shrinkage is one of dental clinicians' main concerns when placing direct, posterior, resin-based composite restorations. Evolving improvements associated with resin-based composite materials, dental adhesives, filling techniques and light curing have improved their predictability, but shrinkage problems remain. METHODS: The authors propose restoring enamel and dentin as two different substrates and describe new techniques for placing direct, posterior, resin-based composite restorations. These techniques use flowable and microhybrid resin-based composites that are polymerized with a progressive curing technique to restore dentin, as well as a microhybrid composite polymerized with a pulse-curing technique to restore enamel. Combined with an oblique, successive cusp buildup method, these techniques can minimize polymerization shrinkage greatly. CONCLUSIONS: Selection and appropriate use of materials, better placement techniques and control polymerization shrinkage may result in more predictable and esthetic Class II resin-based composite restorations. CLINICAL IMPLICATIONS: By using the techniques discussed by the authors, clinicians can reduce enamel microcracks and substantially improve the adaptation of resin-based composite to deep dentin. As a consequence, marginal discoloration, recurrent caries and postoperative sensitivity can be reduced, and longevity of these restorations potentially can be improved.     

Using packable composites for direct posterior placement

BACKGROUND: Although dentists have been using resin-based composites successfully to restore posterior teeth in Class II situations for several years, creating a functional, anatomical proximal contact remains a clinical challenge for many clinicians. OVERVIEW: This article presents a step by-step technique for creating a predictable proximal contact using a packable resin-based composite as the restorative material. Using a technique that is similar to that for amalgam will enable the dentist to make a successful transition to using composite as an alternative to amalgam in some posterior teeth. PRACTICE IMPLICATIONS: More patients today are well-informed about dental care and are seeking tooth-colored restorative alternatives. Excellent materials and proven techniques are making the transition from traditional metallic restorations easier and more predictable. With this article, the authors aim to help dentists gain confidence in their technique and enable them to provide this service for their patients.     

Longevity of posterior tooth dental restorations

Several forms of restorative techniques are used for posterior teeth. They vary significantly in cost and longevity. The following restorative concepts are the most commonly used: amalgam, resin-based composite, PFM, cast gold alloy restorations and all-ceramic restorations. I suggest that patients be informed about the potential longevity of restorative treatment for posterior teeth as they make decisions about treatment for their oral restorative needs.     

Indirect posterior restorations using a new chairside microhybrid resin composite system

A plethora of choices is available as potential tooth-colored restoratives for the posterior dentition. Advances in adhesive technology and esthetic chairside microhybrid composite resins have permitted clinicians to perform inlay/onlay restorations. The use of adhesive indirect procedures offers advantages such as better control of polymerization shrinkage and anatomical form, when compared to conventional, direct restorative techniques. This article describes the use of a new chairside microhybrid composite system as an indirect restorative material, using semidirect and indirect techniques that can be accomplished within the realm of a dental operatory.     

Scientifically Based Rationale and Protocol for Use of Modern Indirect Resin Inlays and Onlays

The desire to place esthetically pleasing, conservative, functionally stable, posterior restorative materials has steadily increased over the past 20 years. The creation of successful dentin bonding adhesives and appropriate resin luting cements has paved the way for the development of a myriad of indirect resin-based restorative materials. These materials have been specifically designed to overcome the negative attributes of their porcelain counterparts, and to simplify fabrication, insertion, and post-delivery adjustments. Possibly like no other product before, these restorative materials have met with instant clinical acceptance by many practitioners, and concern exists that these materials have not been sufficiently studied to warrant such widespread acceptance. This article presents an overview of the history and development of resin-based, esthetic, indirect systems, and offers the clinician a review of the literature supporting their role in posterior restorative dentistry. Additionally, a scientifically based protocol for preparation, impressing, provisionalization, and subsequent cementation and adjustment of indirect laboratory-processed resin inlays and onlays is presented.
CLINICAL SIGNIFICANCE
This article reviews the history of indirect laboratory-processed resin restorations, reviews available literature supporting their use, and presents a scientifically based protocol for their placement and use as a viable alternative for conservative reconstruction of posterior teeth.     

Considerations About Esthetics of Composite Resin Restorations

There is a tendency to use composite resins as a universal restorative material because of the esthetics of the finished restoration. The author discusses the meaning of "esthetics" in restorative dentistry and details the clinical procedures to improve the esthetic performance of the materials. Indications for the materials are set for initial, isolated lesions in the dentition of patients who are well motivated to good standards of oral hygiene. Only then can composite resin materials be accepted as universal restorative esthetic materials, both in the front and lateral segments of the mouth.     

Complete restoration with resin-bonded porcelain inlays

The use of porcelain inlays, instead of composite resin, as a restorative material for posterior teeth has greatly improved the standards of esthetic dentistry. The development of compatible materials enables the fabrication of all-ceramic restorations on refractory investment material without expensive technical equipment. Special care in and knowledge of this new technique by the dentist and the technician are necessary to obtain restorations with excellent marginal adaptation and a highly esthetic appearance.     

Indirect composite restorations: alternative or replacement for ceramic?

In esthetic restorative dentistry, many new materials have been developed in recent years. These materials are often promoted with little clinical research and dentists use these materials on the recommendations of their peers or simply because they are new. It is the author's opinion that supportive clinical research should be examined before any material can be used with absolute confidence. In the absence of supportive research, there must be sufficient justification for trying new materials. It is the purpose of this article to examine the possible uses of indirect composite in esthetic restorative dentistry and to evaluate whether or not their use is advantageous over the use of ceramic materials.     

Alternative crown systems. Is the metal-ceramic crown always the restoration of choice?

The metal-ceramic crown system still is selected the most frequently because of its strength and versatility. The ability to select metals for color or strength for single units or fixed partial dentures gives great flexibility, but when esthetics of the anterior region are a prime concern, the all-ceramic crown is still an excellent choice. Choice of which all-ceramic system to use is dependent on the strength demands, esthetic needs, amount of tooth structure that can be preserved, and laboratory support available. Where good tooth structure remains but some color, contour, or incisal length changes are desired, the porcelain laminate veneer is an outstanding esthetic and restorative choice. When good labial tooth structure remains but lingual structure is inadequate, a partial veneer gold crown can be an excellent esthetic choice. If moderate tooth structure is lost or moderate staining is present, the Dicor crown is a superb choice. In those instances in which heavy staining is present, a foil or core system should be considered to completely block out the background colors. As the occlusal forces become more of a factor, selection of a restorative system will depend more on strength than esthetic demands. The aluminous porcelain jacket crown still offers great strength and esthetics at a reasonable price. When most of the color is on the surface of the teeth, or when there is a high translucency to the teeth, Dicor can provide very esthetic results, and the Dicor Plus crown offers the opportunity to develop intrinsic shading. When greater strength is required, selection of a foil and core system is suggested, as might be a system that provides a stronger core material, like Alceram or Inceram. These stronger core materials will render improved flexural and compressive strengths, but some increases in brightness may occur with the increased alumina content of the cores. The future in ceramic restorative dentistry may be in the computer-generated crown if ways to develop internal coloring and layered building can be developed and cost can be controlled. Ceramic crowns are best limited to the anterior region of the mouth where occlusal forces normally are less than those found in the posterior region. In selected cases, in which there is no evidence of parafunctional habits, and when the dentist and technician are well versed in functional occlusion and have maximum restorative control of the occlusion, posterior ceramic restorations will be successful. It is important to remember in these cases that porcelain is harder than enamel and very strong in compression.(ABSTRACT TRUNCATED AT 400 WORDS)     

The use of resin-based composite in children

Resin-based composites are an integral component of contemporary pediatric restorative dentistry. They can be utilized effectively for preventive resin restorations, moderate Class II restorations, Class III restorations, Class IV restorations, Class V restorations and strip crowns. Tooth isolation to prevent contamination is a critical factor, and high-risk children may not be ideal candidates for resin-based composite restorations. Important factors to consider during composite placement are isolation, polymerization shrinkage and extent of restoration. When utilized correctly, resin-based composites can provide excellent restorations in the primary and permanent dentition.     

Light curing--an update

Light-cured, resin-based composite is an integral part of esthetic and restorative dentistry. This article reviews the performance and limitations of 4 types of curing lights and predicts that curing lights of the future will use light-emitting diode (LED). Currently, LED curing lights are not as powerful as plasma arc curing (PAC) or quartz tungsten halogen (QTH) lights. For the present, QTH curing lights dominate, but PAC lights cure increments of composite resin more efficiently. This article discusses different curing lights: QTH lights, PAC lights, laser curing units, and LED curing lights. The support for different curing modes (soft, exponential, and pulse delay) to improve marginal integrity and reduce marginal leakage is examined.     

Effect of prophylactic polishing protocols on the surface roughness of esthetic restorative materials

Many polishing protocols have been evaluated in vitro for their effect on the surface roughness of restorative materials. These results have been useful in establishing protocols for in vivo application. However, limited research has focused on the subsequent care and maintenance of esthetic restorations following their placement. This investigation evaluated the effect of five polishing protocols that could be implemented at recall on the surface roughness of five direct esthetic restorative materials. Specimens (n=25) measuring 8 mm diameter x 3 mm thick were fabricated in an acrylic mold using five light-cured resin-based materials (hybrid composite, microfilled composite, packable composite, compomer and resin-modified glass ionomer). After photopolymerization, all specimens were polished with Sof-Lex Disks to produce an initial (baseline) surface finish. All specimens were then polished with one of five prophylactic protocols (Butler medium paste, Butler coarse paste, OneGloss, SuperBuff or OneGloss & SuperBuff). The average surface roughness of each treated specimen was determined from three measurements with a profilometer (Surface 1). Next, all specimens were brushed 60,000 times at 1.5 Hz using a brush-head force of 2 N on a Manly V-8 cross-brushing machine in a 50:50 (w/w) slurry of toothpaste and water. The surface roughness of each specimen was measured after brushing (Surface 2) followed by re-polishing with one of five protocols, then final surface roughness values were determined (Surface 3). The data were analyzed using repeated measures ANOVA. Significant differences (p=0.05) in surface roughness were observed among restorative materials and polishing protocols. The microfilled and hybrid resin composite yielded significantly rougher surfaces than the other three materials following tooth brushing. Prophylactic polishing protocols can be used to restore a smooth surface on resin-based esthetic restorative materials following simulated tooth brushing.     

Restorations of eroded areas

Class V erosion lesions must be restored to reinstate esthetic appearance, overcome sensitivity, or prevent further loss of tooth structure. Restoration has been a problem, but, with the advent of adhesive techniques, it is far less traumatic. The most widely advocated method currently uses composite resin as the primary restorative material with dentin bonding agents. Type III glass ionomer lining cements are also suggested to provide bonding to the dentin. This paper details the requirements for clinical success in the restoration of the Class V erosion lesion using Type II restorative esthetic glass ionomer cements as the primary restorative material with the possible addition of composite resin as a final veneer only if circumstances warrant it.     

Scientifically based rationale and protocol for use of modern indirect resin inlays and onlays

The desire to place esthetically pleasing, conservative, functionally stable, posterior restorative materials has steadily increased over the past 20 years. The creation of successful dentin bonding adhesives and appropriate resin luting cements has paved the way for the development of a myriad of indirect resin-based restorative materials. These materials have been specifically designed to overcome the negative attributes of their porcelain counterparts, and to simplify fabrication, insertion, and post-delivery adjustments. Possibly like no other product before, these restorative materials have met with instant clinical acceptance by many practitioners, and concern exists that these materials have not been sufficiently studied to warrant such widespread acceptance. This article presents an overview of the history and development of resin-based, esthetic, indirect systems, and offers the clinician a review of the literature supporting their role in posterior restorative dentistry. Additionally, a scientifically based protocol for preparation, impressing, provisionalization, and subsequent cementation and adjustment of indirect laboratory-processed resin inlays and onlays is presented.