Current opinion in dentistry最新文献

During this annual review period, the literature reflected the great interest in magnetic resonance imaging as a diagnostic tool for assessing the various types of disk displacement and for postoperative imaging, due to its exceptional visualization of the normal and abnormal temporomandibular joint compared with other imaging modalities. None of the authors doubt the potential of magnetic resonance imaging and the interest shown in defining both the normal range of disk position and the pitfalls in the interpretation is a sound development. Arthrography still has its advantages and seems to be the only competitive imaging modality for the assessment of internal derangement; it also has been shown to detect mediolateral disk displacements. Further improvements may be obtained by double-contrast and digital subtraction techniques. In chronic arthritic diseases such as rheumatoid arthritis, the literature has focused on bone abnormalities depicted with tomography and computed tomography. The potential of magnetic resonance imaging to show other inflammatory changes also has been indicated.

Matrix metalloproteinases are produced by both defense and structural cells of the periodontium. They are capable of a wide range of interstitial tissue degradation activities. Complex regulating mechanisms include cytokine regulation of genetic transcription, secretion in latent form, which requires activation once produced, and inhibition by specific inhibitors. It appears that these proteinases and their inhibitors, regulating molecules, and associated genetic material are all potential diagnostic markers of periodontal disease. In addition, they can be measured from gingival crevicular fluid or whole saliva. Generally, high inhibitor levels indicate health, and high levels of metalloproteinase indicate disease. Metalloproteinases can also be inhibited by the tetracycline family of drugs to produce clinical benefits. The diagnostic and therapeutic potential of matrix metalloproteinases and their central role in the pathogenesis of periodontal disease serve to emphasize their importance to periodontologists.

International surveys demonstrate that the prevalence of pocketing of 6 mm or more is between 5% and 20% for much of the world's population. A recently completed national survey of employed adults found the prevalence of gingival bleeding was 44%, the prevalence of pocketing of 4 mm or more was 14%, and the prevalence of attachment loss of 3 mm or more was 44%. Risk indicators for a higher prevalence of periodontal disease include increasing age, poor education, lack of professional dental care, previous periodontal destruction, tobacco use, and diabetes. African-Americans show a higher prevalence of juvenile periodontitis and adult periodontitis than whites. The female-to-male ratio in juvenile periodontitis may be close to 1:1. Another report during the review period suggests that periodontal disease in adults may have a strong genetic component. A doctoral dissertation demonstrated that the sensitivities of methods used in a national survey to detect pocketing and attachment loss range from 0.24 to 0.87 in a high-prevalence population.

Synthetic bone replacement materials continue to be much discussed in the current periodontal literature. Numerous reports have shown their clinical use in the treatment of intraosseous defects. Periodontal treatment aims also include regeneration of a new functional attachment. Although histologic studies have shown that most of the synthetic bone substitutes can enhance bone formation, they are not able to promote new attachment of periodontal tissues to the root surface previously exposed. Future studies are needed to assess whether these materials could be of use together with growth factors in composite grafts or in conjunction with guided tissue regeneration techniques.

Following advances in periodontal disease etiology and pathogenesis, treatment strategies have evolved to eliminate specific pathogens or suppress the destructive host response. Research indicates that chemotherapeutic agents such as antimicrobials and antimetabolites can alter disease progression; consequently, three delivery systems have been investigated: systemic, topical, and controlled release. Using polymers to control drug administration, controlled-release delivery systems theoretically produce concentration profiles that are more constant and longer lasting than those of other systems. Furthermore, patient compliance can be maximized, and systemic complications avoided. During the past two decades, numerous investigations have been conducted to evaluate the potential role of controlled delivery in periodontal treatment. These investigations fall into two distinct categories: those documenting release kinetics, and those documenting clinical effects. Accordingly, pharmacologic agents can be released from drug polymers at therapeutic levels within the periodontal pocket. Many researchers have demonstrated that controlled delivery of antimicrobial agents such as tetracycline, metronidazole, and chlorhexidine can be effective in reducing the signs of periodontitis. In addition, controlled release of antimicrobial agents can alter the periodontal flora with a decrease in total bacterial mass and pathogenic species. Although the majority of these studies are proof-of-principle trials, many agents have been evaluated with undefined hypotheses, ill-suited outcome variables, unrepresentative patient populations, poor controls, and less-than-ideal therapy applications. The true test of controlled delivery will be the demonstration of its slowing disease progression. While future research will concentrate on developing more ideal polymers and introducing new agents, controlled delivery offers clinicians a potential adjunct or alternative to traditional treatment modalities.

Clinicians are occasionally frustrated in arresting the progress of periodontal destruction. The refractory lesion is a problem with a complex and incompletely articulated cause that results in ill-defined and often misdirected treatment. This paper discusses whether refractory periodontitis is a specific entity or whether other periodontal conditions can become refractory.

Periodontal disease activity is defined clinically by progressive loss of probing attachment and radiographically by progressive loss of alveolar bone. The natural history of periodontal disease was originally considered to be nearly continuous and slowly progressive. Clinical research conducted in the last decade suggests that periodontal disease demonstrates periods of exacerbation and remission. Using sensitive automated probes, studies published during the past year have demonstrated that different patterns of disease activity can exist, and that these patterns may be dependent on the disease threshold. Subtraction radiography continues to be refined, but cost and methodology prevent this diagnostic tool from having widespread clinical application. A variety of clinical, microbiologic, and host-response parameters have been studied for their relationship to periodontal disease activity. Many research groups are attempting to develop a diagnostic test that identifies the risk for development of active disease. A relatively simple test based on the presence of a microbial virulence factor, or the host inflammatory or immune response to the subgingival microflora, may be a practical means for clinicians to detect the active phases of periodontal disease.

Although tooth bleaching has been known to the dental profession for over 100 years, new knowledge is continually surfacing. This review discusses the 1990 to 1991 literature on two nonvital bleaching techniques (thermocatalytic and walking) and three classes of vital bleaching techniques (in-office; dentist-prescribed, home-applied; and over-the-counter kits). The choice for nonvital bleaching is the walking bleach technique, with the use of sodium perborate alone having less potential for cervical resorption. The choices for vital bleaching techniques are either the dentist-prescribed, home-applied technique, the in-office technique, or a combination of the two. Bonding should be delayed 2 weeks after bleaching. Microabrasion is a possible second choice for certain discolorations. These chosen bleaching techniques, when used in a professionally appropriate manner, seem as safe as other commonly used dental treatments.

This article reviews recent reports of interest to practitioners concerned with the damaging effects of drugs and exogenous substances on the oral mucosa. Major topics include the incidence of the use of dentally important drugs in selected populations, lichenoid reactions in oral mucosa, diagnosis and management of mucositis related to cancer therapy, and issues relating to the diagnosis of oral foreign body reactions.