Current opinion in dentistry最新文献

Recent studies have suggested the use of drugs to modulate host response as a new approach in periodontal therapy. In this regard, the tetracycline antibiotics have been found to inhibit host-derived collagenases and other matrix metalloproteinases by a mechanism independent of the antimicrobial activity of these drugs; this effect may suppress connective tissue breakdown during periodontal disease and during a variety of medical disorders including (but not limited to) noninfected corneal ulcers, serious (sometimes life-threatening) skin-blistering diseases, rheumatoid arthritis and osteoarthritis, systemically--as well as locally--induced bone loss, and perhaps even tumor-induced angiogenesis. Two therapeutic strategies based on the host-modulating properties of tetracyclines are currently being developed: 1) the use of low-dose doxycycline (the most potent anticollagenase of commercially available tetracyclines) formulations, which do not appear to result in tetracycline side effects such as the emergence of antibiotic-resistant microorganisms; and 2) the production of a family of chemically modified tetracyclines that have lost their antimicrobial activity, but have retained their anticollagenase activity. A description of several of these compounds and a discussion of their efficacy in inhibiting collagenases in vitro and reducing tissue destruction in several animal models of periodontal and medical diseases is presented.

Clinical lasers are of two types: "soft" and "hard" lasers. Soft lasers are claimed to aid healing and to reduce inflammation and pain. However, few rigorous studies are available to support their use. Surgical hard lasers can cut both hard and soft tissues, and newer varieties can transmit their energy via flexible fiberoptic cables. Many procedures can be performed without local analgesia, and because lasers sterilize as they cut, in spite of current controversies, they promise to find uses in all disciplines of dentistry, including periodontics.

Recent studies show that the bacterial flora in adult periodontitis and peri-implantitis are identical, but there could be a more pathogenic flora (gram-negative bacteria, spirochetes) in the partially edentulous implant case than in the fully edentulous implant case. These data indicate a possible seeding mechanism from the natural tooth pocket to the implant crevice and may place the implant in the partially edentulous case more at risk. Also, understanding of the importance of loading in a progressive sense to prevent retrograde peri-implantitis involving the dental implant has increased; the density of bone must be evaluated more fully to determine the time frame necessary to gain a compact bone capable of withstanding occlusal forces at the bone-implant interface.

A high level of interest in the development of diagnostic tests capable of detecting factors associated with progressing ("active") periodontal disease has continued in the past year. Notable advances and refinements have occurred in subtraction radiographic techniques and in the development of computer-linked, controlled-force periodontal probes. Development and evaluation of new diagnostic tests have also proceeded at a rapid pace. Particular emphasis has been placed on rapid tests for putative periodontal pathogens and detection in gingival crevicular fluid of host-derived enzymes. An intense effort must be made to determine the clinical value of diagnostic tests in longitudinal studies that use state-of-the-art assessments of disease progression.

Glass ionomer cements are recognized for their properties of reliable adhesion to tooth structure and fluoride release. The introduction of light-cured base and liner glass ionomer cements has overcome some of the disadvantages of self-cured materials. During the review period, most papers deal with either fluoride release, microleakage, or adhesion. There were few clinical studies.

The use of aesthetic restorative materials such as cast ceramic, porcelain, and composite resin for the restoration of posterior teeth has increased in recent years, but amalgam remains the most frequently used material. Although stories in the media recently renewed the debate over amalgam safety, amalgam has remained in the armamentarium of the average clinician in large part because of its long positive clinical history, beneficial physical properties, and forgiving handling characteristics.

Management of dental caries patients is taking on a new look. Caries is the clinical manifestation of an oral infection. The primary organisms involved are Streptococcus mutans. The infective nature of the disease has been well researched and reported. Treatment of this infection with antibacterial measures is becoming routine in developed countries. In the United States, the overall caries rate is decreasing. However, the distribution of caries is now skewed. Twenty percent of the population has 60% of the caries. These individuals have a significant level of infection or a major lack of resistance to the organisms and their by-products. Major strategies are being developed to control these infections and limit their recurrence. This review focuses on the developments in prevalence studies, diagnosis, and treatment of the caries infection.

Periodontal disease results in the gradual loss of supporting periodontal tissues, and ultimately, the teeth. Although conventional periodontal therapy can arrest the progression of the disease and allow healing, the resulting tissue is unlike that of the normal, healthy periodontium. Cellular and molecular biologic techniques may facilitate our understanding of the regeneration of the periodontium. This review discusses recent findings in cellular and molecular biology relevant to the biology of periodontal tissue regeneration.

The introduction of bonding agents in restorative dentistry has made it possible to adhere restorative materials to tooth structure. Since bonded restorations were introduced by Buonocore in 1955, extensive research has been conducted to develop systems that bond equally effectively to enamel and dentin. Researchers have identified a micromechanical retention mechanism for the attachment of hydrophobic resin restorative materials to both enamel and dentin that works if appropriate conditioning or priming steps are applied. At the dentin site, the modes of action of current adhesive systems converge to create a resin-dentin interdiffusion zone between the deep dentin structures and the filling material. To incorporate or remove the smear layer in this interdiffusion zone, different adhesion strategies are followed to obtain a resin-dentin bond. In the clinical situation, these modern dentin-bonding systems are more technique sensitive; the thickness of the interface, its elastic capacity, the polymerization efficiency and initiation of the bonding agent, and, finally, the application technique used for the restorative material play an important role in the final result.