When the pour doesn’t go smoothly, the model may have voids, broken teeth, or chalky spots owing to oversaturation of the surfactant/debubblizer, or it may break as it is being separated from the impression. The assistant then places the impression on a vibrator and fills it slowly with stone to eliminate all bubbles ( FIGURE 1). Mixing the stone is as important as taking a good impression, so water is added to the stone to achieve the right consistency. Once an impression arrives at the lab, it will be sprayed with a debubblizer rinse or water prior to pouring because most assistants like me think that a slightly wet impression helps the stone flow through it better. Pouring accurate models is extremely important because inaccurate ones affect subsequent phases of a case. How many times have your staff poured models full of voids? Patients must then return for another impression, and there goes your chair time and product. Padjadjaran Journal of Dentistry is licensed under Creative Commons Attribution 4.WHAT IS ONE OF THE BIGGEST challenges dental assistants face? I would say it’s pouring bubble-free impressions. & amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp lt div class="statcounter"& amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp gt & amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp lt a title="Web Analytics" href="" target="_blank"& amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp gt & amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp lt img class="statcounter" src="" alt="Web Analytics"& amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp gt & amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp lt /a& amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp gt & amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp lt /div& amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp amp gt Visitor Stat There was a significant difference in the direction of the dimensional changes on both the top areas, but not in the base areas and height. As compared to using non-perforated ring trays, the percentage of dimensional changes that occurred were (-) 0.49☐.49 on top area, (-) 8.76☓.95 on base area and (+) 1.19☐.71 in height, respectively. The results showed that the percentage of dimensional changes that occurred by using perforated ring tray were (+) 0.56☐.40 on the top area, (-) 3.54☒.92 on base area and (+) 1.54☐.83 in height, respectively. The dimensional change was determined by comparing the dimension of the dental stone die and its metal master die. Alginate impressions were made on the frustum of cone metal master die with a 7.08 mm base diameter, 7.03 mm top diameter and 9.23 mm height using perforated and non-perforated ring trays with 9.40 mm in diameter and 14.17 mm in height. The objective of this research was to investigate the role of the perforation on the ring trays in producing dimensional changes in the impression by using perforated and non-perforated ring trays. ![]() ![]() The exact causal factor is still unknown and the dimensional change mechanism is still poorly understood. Several causal factors have been proposed such as friction between the impression material and the teeth, the bulk of the impression material, the type of impression materials used, the impression technique, the pouring time and many others. It produces a difference in the dimensions of the object and the model, which leads to the restoration being ill-fitted. Dimensional changes are a common occurrence in impressions, either during or after impression taking.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |