Center for Dental Biomaterials
The Center for Dental Biomaterials concentrates on maintaining and restoring oral health for patients through materials science study and interactions. Dental biomaterials include the natural tissues and biocompatible synthetic materials that are used to restore decayed, damaged or fractured teeth. Natural dental tissues include enamel, dentin, cementum, bone, and other intraoral tissues. Biocompatible synthetic dental material groups include metals, ceramics, polymers and composite structures.
The center was established by Dr. Kenneth J. Anusavice in 1996. Dr. Anusavice has contributed to the materials science knowledge as an editor for multiple editions of Phillip’s Science of Dental Materials book that has wide international use.
Current research includes:
- Fractography of brittle materials including all-ceramic, metal-ceramics and restorative composites
- Resin-based composite wear and polymerization shrinkage
- Fatigue behavior of restorative dental materials
- Effective light curing for polymerization of resin based composite materials
- Adhesion of resin based composites to restorative dental materials and tooth hard tissues
The center is responsible for conducting research with an interdisciplinary and interdepartmental approach transferring basic and applied science and technology of biomaterials to students, graduate students, and faculty, as well as practicing dentists. The main educational goal of the center is to provide an advanced knowledge of research and methodology for materials applications.
- Knowledge of the compositional and microstructural features of preventive and restorative dental materials
- Concepts of biocompatibility
- Definitions and applications of the mechanical and physical properties of dental biomaterials
- Principles of materials science as relate to dentistry
- Education for the proper manipulation and application of dental materials
- Analysis of material and structural defects relevant to clinical failure of dental restorations and prostheses
- Criteria for selecting materials for patient-centered clinical practice
Dr. Jose A Rodrigues is a researcher from the Dental Research and Graduate Studies Division, Department of Restorative Dentistry, Guarulhos University, Guarulhos, SP, Brazil. His research with Dr. Jean-Francois Roulet aims to evaluate the bond and ultimate tensile strengths of a flowable bulk-fill resin composite in MOD cavities using human dental teeth. The factorial design of the study includes one conventional composite resin as a control and the bulk-fill flowable will be tested, comparing the traditional incremental filling technique with the bulk-fill technique in proximal boxes with 4mm or 6mm depth. Additionally, the study uses human teeth to obtain a response closer to clinical conditions, and after the restorations the teeth will be challenged in the newly acquired Chewing Simulator Mechatronik CS-4.8. The chewing simulator will simultaneously change the water temperature from 5 °C to 55 °C every two minutes and apply a 5kg load over the restoration surface each
Eveline Soares is a Ph.D. graduate visitor from Piracicaba School of Dentistry, State University of Campinas, UNICAMP, Sao Paulo, Brazil. She graduated in 2010 from the same dental school and was granted with a scholarship from CAPES, a federal organization from Brazil, to develop part of her thesis project here in the college until April. In her project, she is going to evaluate strategies based on biomimetic analogs that will prevent water degradation of resin-dentin interfaces. She will use mechanical, i.e., microtensile test, and morphological (TEM) laboratorial evaluations. Please, welcome Dr. Soares if you meet her.
The center is assisting guest scientist Kenya Dutra, D.D.S., in finishing her research project, “Microtensile bond strength of composite resin to sound dentin following application of chemical collagen crosslinkers and an antimicrobial agent. She is a second year post-graduate operative dentistry resident resident and a master’s student at Nova Southeastern University’s College of Dental Medicine. Dutra spent two weeks in the center laboratories to learn how to manufacture samples for microtensile testing and to operate the Microtensile OMT-100 machine using the patented Geraldeli Device which is being designed by Odeme Dental Research. She had the privilege being instructed by the inventor, Dr. Saulo Geraldeli.
Patricia Matias, a courtesy scholar in the Department of Restorative Dental Science’s Division of Operative Dentistry, is working with the Center for Dental Biomaterials with the newly acquired Chewing Simulator Mechatronik CS-4.8. Matias is a dental student from the University of Brasilia, Brazil, and will spend 2014 in center’s laboratories. She has learned sample preparation and is now conducting a wear study of four microhybrid composites by submitting them to thermomechanical stress. The mechanical component simulates chewing movements by sliding an enstatite sphere for 0.7 mm under 5kg load over a composite surface repetitively. She plans to subject the samples to 12,000 chewing cycles. The chewing simulator has eight chambers and can simultaneously change the water temperature from 5 °C to 55 °C every two minutes.
Dr. Nader Farhan Abdulhameeed is a research scholar visitor from the University of Baghdad, Iraq. He is working on his master’s, conducting research within the center until September 2014. His research with Dr. Jean-Francois Roulet involves the internal and marginal fit of all ceramic crowns made out of Lithium Disilicate Ceramic and Zirconium Oxide Ceramic as a function of material selection and manufacturing techniques. In an in-vitro study using a factorial design he will fabricate crowns, cement them on dies, embed them with epoxy resin and section them in two different plains using the Isomet 100 precision diamond saw. The evaluation will be done using the Keyence VHX1000 digital microscope which allows convenient measurements of selective parts within the viewed images. The outcome of his research will help formulate recommendations for the practicing dentist about material and manufacturing techniques to optimize the fit of all ceramic crowns.
Residents of the prosthodontics graduate program fulfilled their research requirement in the center
Nicholas E. Goetz ran a project, “Energy Requirements of Light Activating Resin Cements as a Function of CAD/CAM Material Properties: A tested Mathematical Model.” He used the recently acquired MARC Resin Calibrator (Blue Light Analytics) to first determine the light absorption as a function of material thickness and shade of two different materials used for indirect chair side restorations. Then, using the same equipment, he irradiated 1mm thick samples of two different resin cements and by determining the micro hardness of the cured cement was able to calculate the required energy dose to fully cure the cements. Based on the data he calculated the required irradiation time as a function of the restorative materials thickness and cured cement samples of varying thicknesses with the required time. Using micro harness he experimentally verified his calculations. His data will be used to calculate precise curing instructions for the cementation of indirect restorations.
Luiz Henrique Gonzaga wanted to find a solution for a clinical problem, “Crown Decontamination After Try In: Bonding Strength Changes.” Using zirconium oxide and lithium disilicate ceramics, he contaminated samples with saliva and tested different ways of removing the contaminations, which occur clinically in the try-in phase. Then he bonded zirconium oxide cylinders with 50 μm pegs to his samples using a resin cement. The approach enabled him to standardize the thickness of the cement layer. After polymerization of the cement he measured the shear bond strength of the adhesive bond between the cement and the contaminated surfaces using the Ultradent Micro shear bond device. Furthermore he did a fracture analysis using a light microscope. Based on his results he concluded that the best way to solve the problem is to do the surface-conditioning for bonding after the try-in of the restorations.
For a listing of publications and for other biographical information, please refer to the individual websites of specific faculty or staff members.