Science is the fuel for the engine of technology! Science is the fuel for progress in the clinical fields of dentistry, medicine, pharmacy, and nursing! Oral health practice has now entered the era of "evidence-based dentistry," characterized by an increasing societal belief in many nations around the world that clinical practice should be based on scientific information rather than intuition or personal opinion. Scientific inquiry coupled with advances in technology have made enormous progress in the last 100 years - air conditioning, personal hygiene, education, antibiotics, immunization, water purification as well as fluoridation. These and complementary advances have changed the average human life span from 45 years in 1900, to 80 years by 2000 throughout the industrial nations of the world. Science has made a profound difference in the quality of life for billions of people. These benefits coupled to scientific advances are especially evident in modern dentistry and medicine.

Molecular dentistry, the human genome project, transcriptomes and proteomes, have recently opened vast opportunities for the translation of basic science discoveries to oral health care at the chairside and bedside through the intermediary process of clinical and health services research. Although the importance of curiosity and innovations through research have been known and appreciated for thousands of years, education and training of the oral health professional community about the process of discovery, from basic discovery through clinical applications influencing and improving standards of oral health care, has not received sufficient emphasis until recently.

What are some of the highlights? At the end of the 17th century, Antonj van Leeuwenhoek invented the light microscope and he provided excellent descriptions of microbes in dental plaque growing on the surfaces of his teeth. Thereafter, the "cell theory" led to histology and pathology and a variety of microscopes designed to visualize the elements of life even better - scanning and electron microscopy, atomic force microscopy, and confocal microscopy, Through these incredible "ways of seeing and knowing," more than 500 species of bacteria have been identified within the biofilms located upon tooth and oral mucosal surfaces. We now appreciate that these oral microorganisms can become virulent and challenge systemic health through low birth weight, pre-maturity as well as periodontal, pulmonary and cardiovascular diseases.

In the 19th century Gregor Mendel advanced his principles of genetics. In the 20th century international teams of scientists and clinicians defined modern human genetics and their efforts led to the completion of the international Human Genome Project by April 2003; all of the human genes were identified and mapped to their respective locations on chromosomes as well as to mitochondria. A new era of gene-based diagnostics and therapeutics began. Thousands of human genetic diseases can now be identified. Tens of thousands of new therapeutics have and are being developed to provide clinical efficacy, specificity and minimal toxicity in oral health care.

Pharmacogenomics and pharmacogenetics provide new insights into how human genetics variations influence individual drug absorption and utilization during therapy - viral, bacterial and yeast oral and systemic infection therapy; the management of oral lesions (e.g. Herpes, squamous cell carcinoma); the management of bone resorption (e.g. periodontal diseases, osteoporosis, osteopetrosis, osteoarthritis); the management of chronic oral and facial pain (e.g. trigeminal neuralgia); the management of autoimmune disorders (e.g. Sjogren's syndrome with xerostomia; possibly fibromyalgia); and the management of temporomandibular joint diseases and disorders.

Biomimetics ("to mimic biology") describes the new scientific opportunities based upon the recently discovered rules of biology. Today, international teams of scientists and clinicians have the ability and capacity to design and fabricate tissues and organs. Using genetics and stem cell biology methods, biomimetic cartilage, bone, muscle and nerve tissues have been "engineered" and applied to clinical problems. Imagine, this new biomimetic strategy applied through molecular dentistry to improve soft and hard tissue engineering and towards tooth and salivary gland organ regeneration.

Another remarkable advance has been made in "how we clinically visualize diseases and disorders." From Roentgen's discovery of x-radiation and the derivative dental x-rays we now "see" using ultrasound imagining, digital radiography, computer-assisted tomography and many innovations in magnetic resonance imaging (MRI) with biomarker reporter molecules. Recently, a new quantitative laser fluorescence technology has been successfully applied to the visualization of early dental caries in human teeth, heralding yet another opportunity to enhance sensitivity while reducing or eliminating radiation dosage to patients. In tandem, a new threedimensional imaging technology enables 360 degrees of "slices" or craniofacial-oral-dental images to be acquired within 74 seconds using computer-assisted technology and a radiation dosage less than routine x-ray bitewing radiographs. Using non-invasive visualization technologies (CT-Scan, Ultrasound, functional "real-time" macro- and micro- MRI) we see better, we see more, and we "see" with profoundly improved resolution (from centimeter to nanometer).

Oral fluids have become "informative fluids" that can be used for diagnostics, the management of drug therapy, and a number of forensic applications. The science and technology of miniaturization (nanotechnology) now enables a full clinical laboratory to be compressed upon a miniature chip and this "lab-on-a-chip" technology is being applied to rapid and sensitive analyses using saliva as a diagnostic fluid for oral as well as systemic diseases and disorders. These and hundreds of other "scientific and technological highlights" reflect a "tipping point": or that time in human history when scientific discoveries are rapidly translated into improved oral health care for people around the world.

Oral health care is nested within a much larger context that blends social, economic and political processes but it takes much more than scientific discovery and translation to application. In the United States, we have fragmented or segmented health care with profound correlations to SES (social and economic status). For example, the Surgeon's General Report Oral Health in America, released by Surgeon General David Satcher in May 2000, indicated that 110 million Americans do not have dental insurance and that almost one-third of the population does not have access to oral health care. Oral health disparities are very significant in America with particular impact upon children born into poverty, the poor and working poor adult populations, and the poor elderly. Further, we have tensions between dental and medical "enhancements" versus disease- and disorder- directed diagnostics, treatments and therapeutics. We have confusion between conditions versus diseases as recently indicated with respect to obesity versus diabetes or hypertension. Globally, the World Health Organization (WHO) proposed a shift in definition form health being equal to the absence of disease, to health being part of quality of life and a sense of wellness. These major forces of change must be acknowledged. Oral health care is related to education and social values, culture, health values, economics and macro- as well as micro- trends that impact the individual, family, community and population. The emerging opportunities for oral health are enormous!

Suggested Readings

U.S. Department of Health and Human Services. Surgeon General's Report Oral Health in America. U.S. Department of Health and Human Services 2000; Washington D.C.

2. Cohen DW, Slavkin HC. Periodontal disease and systemic disease. In: Periodontal Medicine, Eds. Rose LF, Genco RJ, Cohen DW, Mealey BL, B.C. Decker Inc., Hamiltion, Canada 2000; 1-10

3. International Human Genome Sequencing Consortium. Initial sequencing and analysis of the human genome. Nature 2001; 409:860-921.

4. Venter JC et al. The sequence of the human genome. Science 2001; 291:1304-1351.

5. Evans WE, Relling MV. Pharmacogenomics: translating functional genomics into rational therapeutics. Science 1999; 286: 487-491.

6. Peltonen L, McKusic VA. Dissecting human diseases in the postgenomic era. Science 2001; 291: 1224-1229.

7. Syvanen AC. Accessing genetic variation: genotyping single nucleotide polymorphisms. Nature Reviews: Genetics 2001; 2:930-942.

8. Slavkin HC. Toward molecular based diagnostics for the oral cavity. J. Am Dent Assoc 1998; 129:1138-1143.

9. Slavkin HC. The Surgeon General's Report and special needs patients: a framework for action for children and their caregivers. Special Care Dentist 2001; 21(3):88-94.

10. Slavkin HC. Expanding the Boundaries: Enhancing Dentistry's Contribution to Overall Health and Wellbeing. J. Dental Education 2001; 65:1323-1334

11. Slavkin HC. The Human Genome, Implications for Oral Health and Diseases, and Dental Education. J. Dental Education. 2001; 65:463-479.

12. Genco RJ, Scannapieco FA, and Slavkin HC. Oral Reports. The Sciences 2000; 25-30.

13. Slavkin HC, Baum BJ. Relationship of Dental and Oral Pathology to Systemic Illness. J of Amer. Med. Assoc. 2000; 84: 1215-1217.

14. Eichelbaum M, Evert B. Influence of pharmacogenetics on drug disposition and response. Clin Exp Pharm Physiol 1996; 23: 983-985.

15. Slavkin HC. Applications of pharmacogenomics in general dental practice. Pharmacogenomics. 2003; 4:163-170.

16. Chai Y, Slavkin HC. Prospects for tooth regeneration in the 21st century. Microscopy Research & Technique. 2003; 60-469-479.

Dr. Harold C. Slavkin is Dean of the University of Southern California School of Dentistry and past director of the National Institute of Dental and Crainofacial Research. He will also be presenting the Keynote Address at the 2004 AADC Spring Workshop in Fort Myers, FL.

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