Occlusion for fixed prosthodontics: A historical perspective of the gnathological influence

Occlusion for fixed prosthodontics: A historical perspective of the gnathological influence

Paul H. Pokorny, DDS, MSD,a Jonathan P. Wiens, DDS, MSD,b and Harold Litvak, DMD, MSDc University of Detroit Mercy School of Dentistry, Detroit, Mich; New York University College of Dentistry, New York, NY

Abstract:

This article addresses the historical perspective of the gnathological influence upon the concepts of occlusion for fixed prosthodontics. A critical assessment and subsequent scientific validation of occlusal theories require an un- derstanding of their evolution in the formative years and the subsequent development of effective models for clinical practice. While gnathological concepts offer a structured methodology for prosthodontic procedures, further research is needed to corroborate current occlusal treatment approaches. This review focuses on the “classic” fixed prosth- odontic literature and the currently available scientific literature involving fixed prosthodontic dentate occlusion and gnathology. A MEDLINE search was performed to identify English-language peer-reviewed publications spanning the last 56 years, along with an extensive hand search for years prior. Electronic searches of the literature were performed in MEDLINE using the key words: case series, clinical trials, cohort studies, fixed partial denture occlusion, dental oc- clusion, dental occlusion research, centric relation, incisal guidance, maximal intercuspation, occlusal vertical dimen- sion, and occlusion, in various combinations to obtain potential references for review. A total of 10,382 English-lan- guage nonduplicate titles were obtained for 1950-2006 for the key words “dental occlusion.” Other key word searches produced smaller numbers of articles, many of which were duplicates due to multiple searches and were subsequently eliminated. Manual hand searching of the MEDLINE reference list and other journals of interest was performed to identify any articles missed in the original search. Articles were included for review if they contained emerging occlusal theories, new technologies, or occlusal studies that included multiple subjects in contrast to case reports. (J Prosthet Dent 2008;99:299-313)

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Tooth preparations for complete crowns: An art form based on scientific principles

Tooth preparations for complete crowns: An art form based on scientific principles

Charles J. Goodacre, DDS, MSD,a Wayne V. Campagni, DMD,b and Steven A. Aquilino, DDS, MSc School of Dentistry, Loma Linda University, Loma Linda, Calif., and College of Dentistry, University of Iowa, Iowa City, Iowa

Abstract:

Statement of the problem. No recent literature has reviewed the current scientific knowledge on complete coverage tooth preparations.

Purpose. This article traces the historic evolution of complete coverage tooth preparations and identifies guidelines for scientific tooth preparations.

Material and methods. Literature covering 250 years of clinical practice was reviewed with emphasis on scientific data acquired during the last 50 years. Both a MEDLINE search and an extensive manual search were used to locate relevant articles written in English in the last 50 years.

Results. Teeth should be prepared so that they exhibit the following characteristics: 10 to 20 degrees of total occlusal convergence, a minimal occlusocervical dimension of 4 mm for molars and 3 mm for other teeth, and an occlusocervical-to-faciolingual dimension ratio of 0.4 or greater. Facioproximal and linguo- proximal line angles should be preserved whenever possible. When the above features are missing, the teeth should be modified with auxiliary resistance features such as axial grooves or boxes, preferably on proximal surfaces. Finish line selection should be based on the type of crown/retainer, esthetic require- ments, ease of formation, and personal experience. Expectations of enhanced marginal fit with certain finish lines could not be validated by recent research. Esthetic requirements and tooth conditions deter- mine finish line locations relative to the gingiva, with a supragingival location being more acceptable. Line angles should be rounded, and a reasonable degree of surface smoothness is desired.

Conclusion. Nine scientific principles have been developed that ensure mechanical, biologic, and esthet- ic success for tooth preparation of complete coverage restorations. (J Prosthet Dent 2001;85:363-76.)

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Oral Cancer: Enduring Characteristics and Emerging Trends

Oral Cancer: Enduring Characteristics and Emerging Trends

Molly S. Rosebush, D.D.S., M.S., Shailaja Kishan Rao, Ph.D, Sandeep Samant M.D., Weikuan Gu, Ph.D, A Charles R. Handorf M.D., Ph.D, Lawrence M. Pfeffer, Ph.D, Christopher A. Nosrat, D.D.S., Ph.D

Abstract:

Oral cancer is arguably the most serious condition that dental providers may encounter in their practice. The relatively poor prognosis associated with oral cancer highlights the importance of the dental team’s awareness of the disease. While many characteristics of oral cancer have endured over time, new research is revealing trends that are changing the way we approach its screening, diagnosis and treatment. In this report, we provide a translational overview of oral cancer, including risk factors, signs and symptoms, clinical management, as well as our recent findings on the role of chronic inflammation in the development of the disease. In addition, our recent genetic profiling approach in both cancer cell lines and in patients has identified potential biomarkers, molecular pathways and therapeutic drugs (Velcade® and Aspirin®) for oral squamous cell carcinomas. This comprehensive review should be of interest to all dental professionals.

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