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ePaper created 2016-04-13, 09:49:10 | version 1.38.0
2016 Pakistan Edition DENTAL TRIBUNE 7CLINICAL PRACTICE January Cast mounting using MaxAlign: The clinical component Continued from page 06 the treatment modality, the records obtained with Max provided valuable information for the clinician, the patient and third-party insurance. If treatment is to proceed, important information on occlusion, guidance and aesthetic determinants will be accurately conveyed to the laboratory. Utilisation of the clinical component of Max provided a very simple approach to capturing the clinical data. The process was straightforward, the anatomical guides proved very useful and the record of occlusion provided additional crucial information that is often omitted. There were no software glitches or errors during operation. The patient also found the process extremely quick and comfortable. Max has several safeguards to guarantee optimisation. There is a sensor to ensure it is prop erly positioned when taking the photograph of the patient. If it is not properly positioned, image capture will not occur. Calibration may be required in order to ensure that the sensor is correctly set. This is achieved by positioning the tablet vertically in the stand and then pressing the “calibrate sensor” button. The sensitivity of the positioning sensor may also be adjusted with the “adjust sensitivity” button. If the clinician has become frustrated and must take the image immediately, there is a “force capture” button that will override the sensor and take an image. Future development may consider the option of saving the image in STL format. This would enable various output options and use with other digital image and design software. Conclusion Max provides a novel and innovative approach to the mounting of casts using a tablet, reinforcing the anatomical and aesthetic considerations when establishing a simulated patient case. The accurately mounted tangible casts provide substantial information for diagnostic and treatment planning, beneficial to dental students, new graduates and experienced clinicians. Compared with traditional approaches, such as facebow transfer, Max provides an easy, efficient and accurate method for clinical information acquisition that has benefits for both the clinician and patient. Its ease of use would perhaps encourage clinicians to consider uti - lising Max as a vehicle for obtaining crucial clinical data. This would enable greater overall communication, improved success in prosthesis fabrication, and a more satisfying experience for the patient and clinician. Click here! Digital impression margination made easy ne of the primary reasons I embraced CAD/CAM dentistry 20 years ago was the promise that the chairside digital workflow offered in exercising more control over every aspect of the restorative process. Even today, the idea of creating quality dental restorations in one visit for my patients is quite appealing. I have found, however, that in order to cause the vision to crystalize into a beautiful IPS e.max CAD restoration for a patient, I need more than just the furnace required to crystalize the restoration. I need a clinical technique that is precise, repeatable and efficient. While the CAD/CAM workflow is composed of many steps, each essential in their own respect, this “quick tip” will focus on establishing clear, clean and dry preparation margins in support of the digital impression and restoration bonding processes. Preparation before preparation Before we spin up the turbine on the handpiece, two steps will lay the foundation for success. The first is to evaluate the patient’s periodontal status and consider any treatment required to achieve periodontal stability, because we know that excessive bleeding during the procedure will place the outcome at risk. The second is to consider whether the preparation margins are to be subgingival and, if so, place a length of dry, knitted retraction cord (Knit-Pak, Premier Dental Products, Plymouth Meeting, Pa.). As a guide for what size cord to use, determine the minimum probing depth in the region of the sulcus that will adjoin a subgingival margin and then subtract that number by “1” to arrive at the cord size. So, for instance, if the minimum probing depths for the facial and interproximals for the teeth to be veneered was 2 mm, then the #1 cord was placed. It is important to place the required cord prior to beginning the preps as they will provide some protection against soft-tissue trauma imparted by the bur during preparation. Another hedge against insulting the gingiva during preparation is to use a finishing grit diamond bur (round-end taper 782.8F, Premier Dental Products) to finalize the position of subgingival margins. Even with these hemorrhage prevention measures, some bleeding may occur and/or the tissues may become edematous during the preparation process. If nothing is done to mitigate the bleeding or edema, the quality of the digital impression and, later in the procedure, the adhesive bond will both be compromised. The next line of defense against these clinical complications is application of a hemostatic retraction paste for two minutes (Traxodent, Premier Dental Products). This is followed by copious rinsing and thorough drying. When drying the area, care should be taken to thoroughly dry each sulcus as the cord in place acts as a wick for moisture, and it will require more time to dry than the teeth themselves. It is also helpful during the procedure to use a soft-tissue retraction device to gain better access and to prevent the retraction paste from being displaced during the two-minute material action period (Comfort-View, Premier Dental Products). After rinsing and drying, one should inspect the margins carefully and expect to clearly see them from the occlusal and/or facial aspect. At this point, the digital impression may proceed with ease. In the case pictured, the veneer preparation impression was captured using the Planmeca PlanScan scanner (Planmeca USA, Roselle, Ill.). During live scanning, the margins are clear and visible on the screen, just as they were in the mouth. A quality digital impression will carry over to a higher degree of confidence in subsequent steps, such as marking the margins on the virtual model. Preparation is critical to achieving the final result for a patient. While the design process is not shown here, you can see the precision of this patient’s restoration, milled with Planmeca PlanMill40. Re-application of Traxodent (Premier Dental Products) prior to bonding, using the same technique previously described, will help to ensure that the marginal areas of the teeth are dry and exposed. The combined use of a general soft-tissue retractor (Comfort View), dry cord (Knit-Pak) and hemostatic retraction paste (Traxodent), described herein, have the combined effect of supporting an ideal treatment outcome as illustrated in the post-treatment appearance of these veneers. While this clinical workflow was presented in the context of chairside digital CAD/CAM dentistry using the Planmeca FIT system (Planmeca USA), one should appreciate its application for all types of digital or physical fixed restorative impressions as well as adhesive bonding procedures. By Alex Touchstone, DDS O In this case, the veneer preparation impression is captured using the Planmeca PlanScan scanner (Planmeca USA, Roselle, Ill.). During live scanning, the margins are clear and visible on the screen, just as they are in the mouth.