Introduction: The hard tissue of the teeth is resistant to heat and acid,  so that the teeth have an important role as a material consideration of forensic dentistry. The humans have the same shape of the teeth around one in two billion. The stimuli of burn with high temperature and sour can be change the picture of macroscopic and microscopic tooth. This is the subject of an interesting comparison in the interests of justice and identification of dentistry. Methods: This research was a quasi experiment to know a change of microscopic teeth on the hard cases tooth-burning and the case hard acid treatment. The sample used were seven teeth, with details of one normal as a comparison, three teeth burned and three teeth soaked in a solution of water of accu. Observations were made using the microscope at 40x enlarged on each tooth. The tooth was documented by means of a photographed and compared with healthy teeth. Results: The results of this study was obtained by observing and comparing the microscopic structure and the obtained differences in the teeth and treated with the picture of normal teeth. Conclusion: Conclusion of this research is on the tooth are burned was visible loss of enamel at the cement-enamel junction as a result of the process of carbonization heat exposure so as to cause a breach of micro on the outer layer of the tooth enamel and thinning of dentin tubules, while the teeth are in the soak water accu (strong acid) seen change in color of enamel, micro cracks due to defective enamel and depletion of tubulus dentine and loss of boundary between the cementum and dentine.

This study aims to synthesize a porous scaffold based on hydroxyapatite and silica using the polymer sponge replication method. In bone tissue engineering technology, the development of porous scaffolds is a topic that is intensively studied because it is expected to be a solution to various problems of conventional bone therapy. In addition to proposing a porous scaffold synthesis method, we also utilize natural waste-based materials such as cockle shells and tin tailings as raw materials in this research. Investigation through x-ray diffraction (XRD) pattern with the goodness of fit coefficient, X 2 = 0.09 shows that the coprecipitation method is effective for the synthesis of hydroxyapatite. Analysis of XRD pattern of tin tailings sand with a value of X 2 = 0.008 showed that the diffraction pattern was related to silica with space group P 41 21 2. The polymer sponge replication method with polyurethane template succeeded in obtaining scaffolds with macropores above 300 μm. Based on the diffraction pattern of the three porous scaffolds prepared with different percentages of HA, it is known that all porous scaffolds have peaks related to HA and silica. It indicates that the decomposition temperature of polymer does not provide sufficient energy for the HA and silica to transform or react chemically.