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Fabricating a simple closure guide for the dual-arch impression technique
Fabricating a simple closure guide for the dual-arch impression technique Stephen M. Keesee, DDS,a Stephen M. Cameron, DDS,b and Thomas B. Lefler, DMDc US Army Dental Activity, Fort Gordon, Ga.
Dual-arch impressions have been shown to be more accurate than complete-arch impressions when prepared properly.1,2 One of the major pitfalls of making a dual-arch impression is the failure of the patient to properly close into the maximum intercuspation position (MIP).3,4 Moreover, determining whether MIP has been achieved can be a challenge for the operator. For example, if the patient has no posterior occlusion on the side opposite the impression, it may be extremely difficult for the operator to know when maximum intercuspation has occurred. A simple, inexpensive acrylic resin guide can be fabricated to both guide the patient into MIP and allow the operator to verify that the patient has reached MIP.
PROCEDURE Mix autopolymerizing acrylic resin, and allow it to reach a doughy consistency. Mold it around the teeth on the side opposite of where the impression will be made, where it will be readily visible during the impression procedure. Instruct the patient to close into MIP. As the material is setting, instruct the patient to open and close, being careful not to distort the acrylic and making sure that the resin material can be removed from around the teeth. After the material has set, remove it from the teeth and trim it. It should be checked with articulating film to make sure it does not impede closure (Fig. 1) and should “lock” the patient at MIP (Fig. 2). Eccentric movements should be difficult for the patient and recognizable to the operator. The dual-arch impression then can be made successfully on the first attempt.
Fig. 1. Completed occlusal guide shown in position on canine on side opposite of where dual-arch impression will be made. Notice occlusal contact marks on lingual surface of anterior teeth after adjustment of guide to ensure complete closure in MIP.
REFERENCES 1. Douglass GD. The cast restoration—why is it high? J Prosthet Dent 1975;34:491-5. 2. Davis RD, Schwartz RS. Dual-arch and custom tray impression accuracy. Am J Dent 1991;4:89-92. 3. Parker MH, Cameron SM, Hughbanks JC, Reid DE. Comparison of occlusal contacts in maximum intercuspation for two impression techniques. J Prosthet Dent 1997;78:255-9. 4. Wilson EG, Werrin SR. Double arch impressions for simplified restorative dentistry. J Prosthet Dent 1983;49:198-202.
The views and opinions expressed are those of the authors and do not reflect those of the United States Army or the Department of Defense. aResident, Prosthodontic Residency Program. bDirector, Prosthodontic Residency Program. cAssistant Director, Prosthodontic Residency Program. J Prosthet Dent 2001;85:418. 418 THE JOURNAL OF PROSTHETIC DENTISTRY
Fig. 2. Teeth in occlusion are “locked” in position. MIP can be verified visually.
Reprint requests to: DR STEPHEN M. KEESEE TINGAY DENTAL CLINIC US ARMY DENTAL ACTIVITY FORT GORDON, GA 30905-6500 FAX: (706)787-5519 E-MAIL: [email protected] 10/4/114274
doi:10.1067/mpr.2001.114274
VOLUME 85 NUMBER 4
Dual-arch impressions have been shown to be more accurate than complete-arch impressions when prepared properly.1,2 One of the major pitfalls of making a dual-arch impression is the failure of the patient to properly close into the maximum intercuspation position (MIP).3,4 Moreover, determining whether MIP has been achieved can be a challenge for the operator. For example, if the patient has no posterior occlusion on the side opposite the impression, it may be extremely difficult for the operator to know when maximum intercuspation has occurred. A simple, inexpensive acrylic resin guide can be fabricated to both guide the patient into MIP and allow the operator to verify that the patient has reached MIP.
PROCEDURE Mix autopolymerizing acrylic resin, and allow it to reach a doughy consistency. Mold it around the teeth on the side opposite of where the impression will be made, where it will be readily visible during the impression procedure. Instruct the patient to close into MIP. As the material is setting, instruct the patient to open and close, being careful not to distort the acrylic and making sure that the resin material can be removed from around the teeth. After the material has set, remove it from the teeth and trim it. It should be checked with articulating film to make sure it does not impede closure (Fig. 1) and should “lock” the patient at MIP (Fig. 2). Eccentric movements should be difficult for the patient and recognizable to the operator. The dual-arch impression then can be made successfully on the first attempt.
Fig. 1. Completed occlusal guide shown in position on canine on side opposite of where dual-arch impression will be made. Notice occlusal contact marks on lingual surface of anterior teeth after adjustment of guide to ensure complete closure in MIP.
REFERENCES 1. Douglass GD. The cast restoration—why is it high? J Prosthet Dent 1975;34:491-5. 2. Davis RD, Schwartz RS. Dual-arch and custom tray impression accuracy. Am J Dent 1991;4:89-92. 3. Parker MH, Cameron SM, Hughbanks JC, Reid DE. Comparison of occlusal contacts in maximum intercuspation for two impression techniques. J Prosthet Dent 1997;78:255-9. 4. Wilson EG, Werrin SR. Double arch impressions for simplified restorative dentistry. J Prosthet Dent 1983;49:198-202.
The views and opinions expressed are those of the authors and do not reflect those of the United States Army or the Department of Defense. aResident, Prosthodontic Residency Program. bDirector, Prosthodontic Residency Program. cAssistant Director, Prosthodontic Residency Program. J Prosthet Dent 2001;85:418. 418 THE JOURNAL OF PROSTHETIC DENTISTRY
Fig. 2. Teeth in occlusion are “locked” in position. MIP can be verified visually.
Reprint requests to: DR STEPHEN M. KEESEE TINGAY DENTAL CLINIC US ARMY DENTAL ACTIVITY FORT GORDON, GA 30905-6500 FAX: (706)787-5519 E-MAIL: [email protected] 10/4/114274
doi:10.1067/mpr.2001.114274
VOLUME 85 NUMBER 4