MAJOR AREAS 

• Biomedical engineering of polymer matrix composites and implantable biomedical devices
• Numerical modeling and biophysical measurement of stress and strain resulting from polymerization shrinkage of polymer matrix composites
• Numerical modeling and prediction of physical properties of polymer matrix composites using micromechanics algorithms
• Numerical modeling of materials testing devices and implantable cardiovascular devices
• Implementation and utilization of digital and Internet resources for education and research
   

PREVIOUS POSITIONS 

July 1984 - July 1994
Associate Professor (Research Associate 1984-1986, Assistant Professor 1986-1992)
Minnesota Dental Research Center for Biomaterials and Biomechanics
Unversity of Minnesota School of Dentistry
Minneapolis, Minnesota

July 1980 - July 1982
Assistant Professor of Surgery
Chicago College of Osteopathic Medicine
Chicago, Illinois
 

EDUCATION 

• University of Greenwich, London, England

  Doctor of Philosophy, Biophysical and Numerical Analysis, 1988
  Dissertation:  A Biophysical Analysis of Occlusal Wear of Dental Materials
   

• University of Minnesota, Minneapolis, MN

  Master of Science, Dentistry (Prosthodontics), 1984
  Minor Field of Study: Electrical Engineering
  Thesis: Acoustic Analysis of Temporomandibular Joint Function
   

• Northwestern University Dental School

  Doctor of Dental Surgery, 1980
   

• University of California Los Angeles

   Bachelor of Science, Cybernetics (biomedical engineering), 1976
   

RESEARCH INTERESTS 

Numerical simulations are important in establishing fundamental knowledge about biological processes and insights into the performance of biomedical product designs. We are applying numerical simulation technology in two major areas: polymerization contraction of polymer matrix composites and functional evaluation of intravascular stents dental implants. Our integrated experimental and numerical approach uses servohydraulic testing equipment, dynamic thermomechanical analysis, strain gauges, and other displacement instrumentation to determine material properties and boundary conditions. Graphics workstations and supercomputers are used to solve the massive system of equations for the analysis.

This integrated experimental and computational approach provides insights into the biomechanics of materials and prostheses. By incorporating the effects of the micromechanical properites of composite shrinkage on the investing tissues, various handling methods have been simulated to develop a technique that reduces the effect of polymerization contraction. Numerical simulation assists in the interpretation of clinical observations and provides mechanisms for solution of clinical problems.
 

SELECTED RECENT PUBLICATIONS 

Sakaguchi RL, Wiltbank BD, Murchison CF. Contraction force rate of
polymer composites is linearly correlated with irradiance. Dent Mater.
2004 May;20(4):402-7.

Sakaguchi RL, Wiltbank BD, Murchison CF. Prediction of composite
elastic modulus and polymerization shrinkage by computational
micromechanics. Dent Mater. 2004 May;20(4):397-401.

Sakaguchi RL, Wiltbank BD, Shah NC. Critical configuration analysis of
four methods for measuring polymerization shrinkage strain of
composites. Dent Mater. 2004 May;20(4):388-96.

Lee JK, Choi JY, Lim BS, Lee YK, Sakaguchi RL. Change of properties
during storage of a UDMA/TEGDMA dental resin. J Biomed Mater Res. 2004
Feb 15;68B(2):216-21.

Vandewalle KS, Ferracane JL, Hilton TJ, Erickson RL, Sakaguchi RL.
Effect of energy density on properties and marginal integrity of
posterior resin composite restorations. Dent Mater. 2004
Jan;20(1):96-106.

Sakaguchi RL, Shah NC, Lim BS, Ferracane JL, Borgersen SE. Dynamic
mechanical analysis of storage modulus development in light-activated
polymer matrix composites. Dent Mater. 2002 May;18(3):197-202.

Lim BS, Ferracane JL, Sakaguchi RL, Condon JR. Reduction of
polymerization contraction stress for dental composites by two-step
light-activation. Dent Mater. 2002 Sep;18(6):436-44.

Sakaguchi RL, Ferracane JL. Effect of light power density on
development of elastic modulus of a model light-activated composite
during polymerization. J Esthet Restor Dent. 2001;13(2):121-30.

Sakaguchi RL and Ferracane JL. Effect of light power density on
development of elastic modulus of a model light-activated composite
during polymerization. J Esthet Restor Dent 2001;13(2):121-30

Sakaguchi RL. A review of the curing mechanics of composites and their
significance in dental applications. Compend Contin Educ Dent Suppl.
1999 Nov;(25):S16-23; quiz S73. Review.

Sakaguchi RL and Berge XH. Reduced light energy density decreases
post-gel contraction while maintaining degree of conversion in
composites. Journal of Dentistry 1998; 26:695-700.

Sakaguchi RL and Ferracane JL. Stress transfer from polymerization
shrinkage of a chemical-cured composite bonded to a pre-cast composite
substrate. Dental Materials 1998; 14:106-111.

Sakaguchi RL, Versluis A, Douglas WH. Analysis of strain gage method
for measurement of post-gel shrinkage in composite resins. Dental
Materials 1997; 13:233-239.

Versluis A, Douglas WH, Cross M, Sakaguchi RL. Does an incremental
filling technique reduce polymerization shrinkage stresses? Journal
of Dental Research, 1996; 75(3):871-878.

Versluis A, Douglas WH, Sakaguchi RL. Determination of the linear
thermal expansion coefficient using strain gages. Dental Materials
1996; 12:290-294.

Maeda Y, Nishida K, Sakaguchi RL. Screw mechanics in dental implants
and their clinical implications. Quintessence Dental Implantology 1996;
3:2, 34-39.

Sakaguchi RL, Borgersen SE. Biomechanics of Screw-Retained Implant
Prosthesis. Quintessence Dental Implantology 1996; 3:1, 29-38.

Drummond JL, Sakaguchi RL, Racean DC, Wozny J, Steinberg AD. Testing
mode and surface treatment effects on dentin bonding. Journal of
Biomedical Materials Research 1996; 32:533-541.

Sakaguchi, R.L. and Borgersen, SE. Nonlinear contact analysis of
preload in dental implant screws. Int. J. Oral Maxillofac. Implants
1995; 10:295-302.

Sakaguchi RL. Simulation and Visualization Methods in Biomedical
Research. J Artificial Intelligence in Dentistry 1995; 5(1):16-18