Development of Artificial Carious Dentin for Dental Education Purposes Grant uri icon

abstract

  • Hypothesis, specific aims, and overall goals for the project: Surgical removal of carious tooth tissues is an essential hand skill learning for dental students to master. Current training of DDS or DMD students in operative dentistry procedures are heavily taught in plastic teeth with very few exercises on existing simulated carious teeth are practiced in dental schools. Moreover, the existing caries simulated teeth can present up to 70% of manufacturing defects that resulted in caries overextension resulting in negative summative assessment on practical examinations. There is a need of a realistic educational model for preclinical surgical removal of carious affected dental tissues that improved students' tactile hand-skill dexterity prior to delivering dental care in outpatient dental clinics. The objective of this study is to develop a process that creates artificial-like carious dentin tissues. Here we will test the research hypothesis that a hydroxyapatite-gelatin (HA-GEL) composite scaffold can be strategically mineralized via automated alternated soaking process (ASP) (Strange &; Oyen, 2011, Fig. 1) to mimicry the mechanical properties of natural carious lesions (Fig 2). This hypothesis will be tested in pursuit of the objective through the following specific aims: a) to evaluate the ultra-morphology of the mineralized HA-GEL composite with scanning electron microscopy, b) to test the hardness behavior of the mineralized HA-GEL composite. Our long-term overall goal for this research project is to develop a reliable hand skill model for training of dental students with removal of carious tissues. To achieve these specific aims, calcium (Ca+) solution is prepared by dissolving calcium chloride dihydrate (CaCl22H2O, Sigma-Aldrich) in 10 times diluted 1M trizma hydrochloride pH 7.4 buffer solution (Tris - HCL). The phosphate (PO43-) solution is prepared by dissolving 120 mM of sodium phosphate dibasic (Na2HPO4, Sigma-Aldrich) in deionized water. The pH of the phosphate solution is adjusted to 7.4 using 1M hydrochloric acid (HCL, Fisher Scientific). Gelatin (180 bloom, Sigma-Aldrich) is added at 25 g per 225 mL of each of the Ca+ and PO43- solutions and stirred at least ten minutes at 70�C. The solutions are placed in a heated water bath and allowed to equilibrate to 50 �C, alongside 2 beakers containing 250 ml of deionized water. The solutions were kept at a temperature of 50 �C throughout the experiment, to ensure that the gelatin remained molten (the melting point of gelatin is approximately 35 �C), and to maintain a high rate of reaction. The substrate is submerged in cycles in the [calcium solution, water, phosphate solution, water] sequence for 20-200 cycles (refreshing solutions after every 30 cycles) depending on the thickness of material required. The process is automated with a Lego Mindstorms robotic crane (Figure 1). Upon process completion, the samples are dried for 24-72 hours in a desiccator prior to evaluation. Following known processing methods, sample of the mineralized hydroxyapatite-gelatin (HA-GEL) composite scaffold are ultra-morphologically evaluated with a scanning electron microscope (EVO 10, Zeiss) and FTIR (Lumos II, Bruker), and mechanically tested with a nanoindentor (eNano, KLA). Whenever necessary, appropriate statistical analysis shall be used to analyze the data. If success is achieved, we will pursue translation into a 3D printed carious tooth for dental education.

date/time interval

  • March 2020