FUTURE OFDENTISTRYu There will be an expanded phase of functional
genomic analyses following an extended period of
rapid advances in genetics and genome-based
research; and
u There will be a greater emphasis on applied
research, including domestic and international collab-
orative, translational, and clinical research;
epidemiology; oral health promotion; and health
services research.
Barriers to entering a career in research included a
lack of candidates with an expressed interest in
research, a relative lack of workforce diversity, student
debt, and misconceptions about the rewards of a career
in research. Lack of a diverse pool of mentors also dis-
courages the consideration of research as a career.
Of great importance to the future of dentistry is the
need to promote the clinician scientist who will be
able to work in an interdisciplinary environment, to
transfer basic findings to the clinical setting (transla-
tional research), to design clinical trials, and
to undertake health promotion research. All such
dental clinician scientists should receive formal train-
ing to become a member of a clinical research team.
While this strong emphasis on training may
appear to contradict the recent National Research
Council report that did not call for expansion of
Ph.D. training in the biomedical sciences, this does
not apply to dental and craniofacial research. The
NIDCR report calls for targeted training.
This chapter includes a discussion of dental bio-
materials and summaries of the current status of
research for nine selected diseases and conditions:
u Dental Caries/Dental Biomaterials;
u Periodontal Diseases;
u Systemic Diseases;
u Cleft Lip, Cleft Palate and Craniofacial Develop-
ment Disorders;
u Malocclusion and Tooth Agenesis;
u Oral and Pharyngeal Cancers;
u Oral Mucosal and Autoimmune Diseases and
Other Infections;
u Salivary Gland Diseases; and,u Temporomandibular Disorders.The following sections provide examples of the
many disease-specific research areas and provide a
flavor of the breadth of research contributions and
needs.DENTAL CARIES/DENTAL BIOMATERIALSDespite a remarkable decline in prevalence dur-
ing the past 20 years, dental caries continues to be a
major problem in the United States for adults and
children (Kaste et al, 1996; and Winn et al, 1996).
Ninety-four percent (94%) of dentate adults have
evidence of treated or untreated carious lesions, and
23% have carious lesions on their root surfaces.
Furthermore, although 25% of 5-17 year olds have
80% of carious lesions, by age 17, 40% of the pop-
ulation has 80% of carious lesions. Dental caries
remains the most prevalent disease of childhood.
The decline in the prevalence of carious lesions
has been a result of water fluoridation and fluoride-
containing products, such as fluoride dentifrice, var-
nishes and restorative materials (Burt and Fejerskov,
1996; and Jenkins, 1985). Where one or both of
these measures are in place, the prevalence of cari-
ous lesions has generally been stabilized.Dental Caries as an Infectious DiseaseThe initiation and progression of dental caries are
attributable primarily to cariogenic bacteria, espe-
cially Streptococcus mutansand recently identified
lactobacilli. Root caries are initiated by the same
bacteria as enamel caries and are manifested by loss
of mineral in the same way as coronal caries. After
the mineral loss, enzymes of bacterial origin degrade
proteins on the root surface. Older persons with
gingival recession are especially at risk.
As an infectious disease, dental caries is a dynam-
ic multifactorial process that involves one or more
tooth tissues (substrate), microorganisms capable of
converting dietary components to demineralizing
acids, deposits of these microorganisms on the teeth
(dental plaque), a sufficient supply and frequency of
dietary nutrients (sugars) to shift the chemical equilib-
rium between the plaque fluid and the tooth to a state
of demineralization, and adequate time for significant
mineral loss (calcium and phosphate) to occur.Dental and Craniofacial Research