Operative Dentistry 

About: Operative Dentistry is an academic journal published by Indiana University School of Dentistry. The journal publishes majorly in the area(s): Dentin & Bond strength. It has an ISSN identifier of 0361-7734. Over the lifetime, 2800 publications have been published receiving 92283 citations.

Buonocore memorial lecture, adhesion to enamel and dentin: current status and future challenges

Abstract: Bonding to tooth tissue can be achieved through an "etch&rinse," "self-etch" or "glass-ionomer" approach. In this paper, the basic bonding mechanism to enamel and dentin of these three approaches is demonstrated by means of ultramorphological and chemical characterization of tooth-biomaterial interfacial interactions. Furthermore, bond-strength testing and measurement of marginal-sealing effectiveness (the two most commonly employed methodologies to determine "bonding effectiveness" in the laboratory) are evaluated upon their value and relevance in predicting clinical performance. A new dynamic methodology to test biomaterial-tooth bonds in a fatigue mode is introduced with a recently developed micro-rotary fatigue-testing device. Eventually, today's adhesives will be critically weighted upon their performance in diverse laboratory studies and clinical trials. Special attention has been given to the benefits/drawbacks of an etch&rinse versus a self-etch approach and the long-term performance of these adhesives. Correlating data gathered in the laboratory with clinical results clearly showed that laboratory research CAN predict clinical effectiveness. Although there is a tendency to simplify bonding procedures, the data presented confirm that conventional three-step etch&rinse adhesives still perform most favorably and are most reliable in the long-term. Nevertheless, a self-etch approach may have the best future perspective. Clinically, when adhesives no longer require an "etch&rinse" step, the application time, and probably more importantly, the technique-sensitivity are substantially reduced. Especially "mild," two-step self-etch adhesives that bond through a combined micromechanical and chemical interaction with tooth tissue closely approach conventional three-step systems in bonding performance.

Buonocore Memorial Lecture. Review of the clinical survival of direct and indirect restorations in posterior teeth of the permanent dentition.

Abstract: This review provides a survey on the longevity of restorations in stress-bearing posterior cavities and assesses possible reasons for clinical failure. The dental literature, predominantly since 1990, was reviewed for longitudinal, controlled clinical studies and retrospective cross-sectional studies of posterior restorations. Only studies investigating the clinical performance of restorations in permanent teeth were included. Longevity and annual failure rates of amalgam, direct composite restorations, compomers, glass ionomers and derivative products, composite and ceramic inlays and cast gold restorations were determined for Class I and II cavities. Mean (SD) annual failure rates in posterior stress-bearing cavities are: 3.0% (1.9) for amalgam restorations, 2.2% (2.0) for direct composites, 3.6% (4.2) for direct composites with inserts, 1.1% (1.2) for compomer restorations, 7.2% (5.6) for regular glass ionomer restorations, 7.1% (2.8) for tunnel glass ionomers, 6.0% (4.6) for ART glass ionomers, 2.9% (2.6) for composite inlays, 1.9% (1.8) for ceramic restorations, 1.7% (1.6) for CAD/CAM ceramic restorations and 1.4% (1.4) for cast gold inlays and onlays. Publications from 1990 forward showed better results. Indirect restorations exhibited a significantly lower mean annual failure rate than direct techniques (p=0.0031). Longevity of dental restorations is dependent upon many different factors, including material, patient- and dentist-related. Principal reasons for failure were secondary caries, fracture, marginal deficiencies, wear and postoperative sensitivity. We need to learn to distinguish between reasons that cause early failures and those that are responsible for restoration loss after several years of service.

Tooth regeneration in operative dentistry.

Abstract: For many years, operative dentistry has been using regenerative approaches to treat dental disease. The use of calcium hydroxide to stimulate reparative or reactionary dentin is clearly an example of such a therapeutic strategy. The advent of tissue engineering is allowing dentistry to move forward in the use of regeneration as an underlying principle for the treatment of dental disease. Tissue engineering is a multi-disciplinary science that brings together biology, engineering and clinical sciences with developing new tissues and organs. It is based on fundamental principles that involve the identification of appropriate cells, the development of conducive scaffolds and an understanding of the morphogenic signals required to induce cells to regenerate the tissues that were lost. This review is focused on the presentation and discussion of existing literature that covers the engineering of enamel, dentin and pulp, as well on the engineering of entire teeth. There are clearly major road-blocks to overcome before such strategies move to the clinic and are used regularly to treat patients. However, existing evidence strongly suggests that the engineering of new dental structures to replace tissues lost during the process of caries or trauma will have a place in the future of operative dentistry.

Nanoleakage: leakage within the hybrid layer.

Abstract: Most microleakage studies involve quantitating the magnitude of movement of a tracer molecule through a gap between restorative materials and the wall of cavity preparations. The present microscopic study examined the migration of silver nitrate into the interface between dentin and five different dentin bonding agents used to restore class 5 cavities, in the absence of gap formation. Several different leakage patterns were seen, but they all indicated leakage within the hybrid layer when viewed by SEM. The ranking of microleakage from most to least was: All-Bond 2 > Suberbond C&B > Scotchbond Multi-Purpose > Clearfil Liner Bond System > Kuraray Experimental System, KB-200. To distinguish this special type of microleakage within the basal, porous region of the hybrid layer in the absence of gap formation, we propose the term nanoleakage.

Effect of light intensity and exposure duration on cure of resin composite.

Abstract: Of the many factors under their control, clinicians can manipulate light-exposure duration but must deal with a set intensity of light emitted from the dental curing unit. This research investigates the interdependence of exposure duration and source intensity on resin cure at various depths within a simulated light-cured resin composite restoration. This wafers of composite were obtained from a simulated cylindrical restoration such that the wafer could be removed from the top or from a distance of 1, 2, and 3 mm beneath the surface. The composites used in this study were a microfill and hybrid of Universal and Gray shades. All the data concerning filler type and shade were pooled so that generalized statements could be made regarding curing of light-activated composite in general. Specimens were cured using various source intensities and for different durations at each level within the cured cylinder. The cure of the specimens resulting from the different treatments was determined using infrared spectroscopy. The results indicate a dramatic effect of depth on the cure of composite. At depths greater than 2 mm, poor cure results, and polymerization is very susceptible to changes in light intensity and exposure duration. From these results, routine exposure times of 60 seconds are recommended using light-source intensities of at least 400 mW/cm2 as measured with a commercial dental light intensity meter. Incremental layer thickness should not exceed 2 mm, with 1 mm being ideal. Sources with intensity values less than 233 mW/cm2 should not be used because of their poor cure characteristics.