Ten Key Elements of Clinical Examination of Silicone Rubber Impression Defects
After making the silicone rubber model in the patient's mouth, it is believed that under normal circumstances, dentists will check the impression making to see if the surface is intact. Are there any shortcomings? What are the defects that need to be reproduced and what are the defects that can be sent directly?
No tray
The occurrence rate of such defects is not high and clinicians are easy to check. As long as there is silicone rubber in such cases, please do not send it out and take the model again.
Separation of impression material from pallet
If the demoulding position is not in the tooth, and the area is small, it can be sent after glue retention. If it appears in the teeth or has a large demoulding area, it is necessary to retrieve the silica gel and send it out.
Impression-free coverage of dentition
Because of the characteristics of the first impression material, it is difficult to ensure the clear and accurate shape of the teeth after removing the impression. If the shape of the teeth is not clear, especially when the marginal line of the gingiva is blurred, it is also necessary to re-take the impression.
Incomplete molar extraction
Such defects occur frequently, and clinicians can evaluate whether such defects need to be retrieved in conjunction with repair schemes. If the molar relationship is maintained and the last crown is taken 1/2, no re-extraction is required. If the molar needs to be designed to move without taking all the teeth, please re-take the model. At the same time, when such defects occur, doctors are asked to indicate whether the relationship between molars is maintained in the commissioned processing sheet or the mid-term feedback form, so as to avoid the unknown plan when acceptance of silica gel and provide defect instructions for feedback to clinical practice.
Layering and folding appeared at the initial and final impressions
Initial and final impressions are usually two kinds of color materials. When clinical examination of silica gel, if some parts have obvious color separation, probe can be used to check whether the edge transition is smooth. If it is found that the two materials can not be well combined or there are steps, please take the model again.
Dental morphology shortage
Sometimes due to the lack of depth of impression bite or the inadequate amount of impression, it will cause the shortage of dental morphology. When the clinician examines, he can evaluate whether to retrieve the defect according to the condition of gingival margin line. The defect below 1/3 of a single tooth can be repaired later, but not retrieved.
Bubble, cavity and impression biting phenomenon
These three defects are also common problems, which can be judged by the position of the defect teeth. Generally, as long as it does not occur at the incisor angle and the cusp, the smaller area can be repaired later, and it does not need to be reclaimed.
Deformation of dental impression
If there is obvious deformity on the surface, it should be retrieved clinically. If there is any discrepancy with the normal tooth anatomy, it can be confirmed by referring to the actual shape of the patient's mouth. If the patient has deformity teeth, at the same time, it should be noted in the commissioned processing sheet or provided in the oral photograph to ensure that the tooth position is clearly photographed and tested with silica gel. The receiving company should refer to the relevant information to determine whether it is defective.
Imperfect solidification of impression
When there is uneven color mixing on the impression surface, the hardness of the impression should be examined with a probe. If incomplete curing is found, the silica gel should be retrieved.
Removable denture not removed
Ask the clinician to remove the removable denture before removing the model. It is also necessary to recapture the silica gel.
Finally, if the defective half-mouth silica gel does not need to be corrected and can be sent without affecting occlusion, please indicate only maxillary/mandibular correction in the commissioned processing sheet or the mid-term feedback form. The defect can be assessed with reference to this information when the silica gel is accepted. At the same time, clinicians are also asked to wash the teeth of patients, and then take the silica gel model, so that the late appliances can better fit the teeth.