Acknowledgements - UCSF School of Dentistry - University of ...

in treating such defects, but the mechanisms are not well understood. Recently, we identified that 45S5 bioglass enhanced collagen
type I and osteocalcin expression in hPDLFs. Several ions were identified as being released by the bioglass, with Silicon ion being
most prominent.
Objectives: The purpose of this study was to determine the effects of silicon ion on hPDLFs, in comparison to whole extracts of
45S5 Bioglass.
Methods: Glass conditioned medium (GCM) was prepared by soaking 45S5 glass powders in DMEM for 3 days to make 45S5 ion
extracts. Silicon medium was prepared by dissolving sodium metasillicate in DMEM. All media was sterile-filtered and supplemented
with 10% FBS, 1% pen-strep, and 1% fungizone. Human periodontal ligament fibroblasts were cultured in either control media,
silicon media, or GCM, and the medium was changed every 2 days for up to 16 days. All experiments were carried out in triplicate.
At days 2, 4, 8 and 16, cultures were stopped and submitted for gene analysis. At day 16, cultures were also submitted for protein
analysis.
Results/ Conclusions: The results of this work are currently in progress, and may provide new tools for understanding how silicon
ions regulate osteogenesis.
Support: American Association of Dental Research (AADR) Student Research Fellowship and The Department of Orofacial
Sciences
II. GRADUATE CATEGORY
#29 Title: Odontoblasts of Immature Rat Molars Lack Expression of TRPV1
J J EMRICK (1) and D J JULIUS (2)
(1) UCSF Department of Preventive and Restorative Dental Sciences, (2) Department of Physiology
Introduction:Thermal changes in the oral cavity are a common trigger of dental pain (Pashley, 1996). Members of the transient
receptor potential (TRP) family of ion channels are responsible for initiating the cellular mechanisms of thermal sensation and
nociception. Specifically, TRPV1 is responsible for detecting noxious heat (Caterina et al., 1997), and is functionally expressed in
mouse and human odontoblasts (Son et al., 2009; El Karim et al., 2010). Recent evidence in adult rats suggests that TRPV1
expression in odontoblasts may be limited to immature teeth without fused apices (Yeon et al., 2009).
Objective: We studied rat odontoblast expression of TRPV1 in molars prior to maturation of the apices using microfluorometry.
Methods: Odontoblasts were prepared as previously described in Guo, et al., 1999. Briefly, maxillary and mandibular first and
second molars were extracted from 4 week old Sprague-Dawley rats following CO2 euthanasia and cervical dislocation. Apices
were visibly open in all molars. Molar crowns were isolated from roots above the level of the cementoenamel junction (CEJ) then
fractured. Crown segments and associated pulpal tissue containing odontoblasts were enzymatically digested in collagenase IA and
protease I then triturated using a series of Pasteur pipettes. Odontoblasts were plated onto a Matrigel and poly-D-Lysine substrate;
loaded with ratiometric calcium indicating dye, Fura-2-acetoxymethyl ester (Fura-2 AM); then subsequently stimulated with selective
TRPV1 agonist, capsaicin (20 µM). Cell vitality was confirmed by trypan blue staining.
Results:Odontoblasts were identified principally on the basis of phenotype and successful loading with Fura-2 AM. Capsaicin did
not elicit a response from odontoblasts. Trypan blue stain confirmed odontoblasts’ vitality.
Conclusion:The lack of TRPV1 expression in rat molar odontoblasts is consistent with recent studies (Yeon et al., 2009). The
absence of rat odontoblasts’ expression of TRPV1 in mature or immature teeth may represent a key difference from human or
mouse odontoblasts.
Support: COHORT,T32:DE0073060-16
#30 Title: Acceptability, feasibility and utilization of two automated formats for phone-based oral health education
K S HOEFT (1), M J GONZALEZ-VARGAS (1), Z ROMAN (1), C KAVANAGH (1), J MURRAY (1), B HECKMAN (1), D
SCHILLINGER (2), M HANDLEY (3), J C BARKER (1), S A GANSKY (1), M M WALSH (1)
(1) Center to Address Disparities in Children's Oral Health (CAN DO), UCSF Department of Preventive and Restorative Dental
Sciences, (2) Department of Medicine; (3) Department of Epidemiology and Biostatistics
Objectives: To assess the acceptability, feasibility and utilization of two automated formats of a phone-based oral health (ECC)
education program among a convenience sample of low-income English and Spanish-speaking parents of children aged 1-3 years.
Methods: Qualitative interviews ranging 30 to 90 minutes were conducted with parents to assess the acceptability of passive (tollfree
number on a brochure) versus proactive (automatically generated call plus brochure) phone education formats. Qualitative data
were transcribed and thematically analyzed by trained researchers. Sampling for acceptability, feasibility and utilization data was
conducted at two WIC and two community health clinic sites. Quantitative phone call data was collected via the automated phone
system and statistical analyses were done with STATA software.
Results: Thirty one (17 English, 14 Spanish) qualitative interviews were conducted. Both formats were acceptable to parents of
both languages. Thirteen of 56 parents (23%) who agreed to be contacted for the automated phone education answered the call
and stayed on the line to hear the information. Spanish-speaking parents had four times the odds of completing such educational
calls compared to English-speaking parents (adjusted odds ratio of 4.34 (95% CI: 1.03, 18.3). Only 2 parents called the toll-free
number for education.
School of Dentistry Research and Clinical Excellence Day 2011 Program 14