A threaded ball for the survey of mounted casts

THE

JOURNAL

OF PROSTHETIC

TOTH

DENTISTRY

Fig. 1. Preoperative view of multiple pin-retained cement core.

Fig.

The pin is engagedlaterally, with the tip of the scalerrotating anticlockwise. Removal times are generally no more than 20 seconds;however, I have had experience with somethat required up to 4 minutes. Removal of a sectioned pin is possible by rotating the ultrasonic scaler on the sectioned face of the pin. Generally the resultant hole may receive another pin. Preliminary experiments reveal that a larger pin is usually required to engagethe original hole.

A threaded Richard

W. Toth,

ball for the survey DDS,

MS,a

and

FIEBIGER

2. Postoperative removal of pins with ultrason.ics.

This method is recommendedfor pin removal with low force and flexibility of accessto the pin. Reprint

requests

to:

DR. PETER R. WILSON SCHOOL OF DENTAL SCIENCE UNIVERSITY OF MELBOURNE 711 ELIZABETH ST. MELBOURNE VIC 3000 AUSTRALIA

of mounted

Guy E. Fiebiger,

AND

casts

DMDb

Naval Dental Center, Norfolk, Va., and School of Dentistry, Collegeof Georgia, Augusta, Ga. Surveying and machining restorations on mounted casts with a standard survey table is awkward. Mounted casts attached to a modified survey table are stable,t but may not fit vertically to the surveyor becauseof the spacetaken up by the cast mounting and the surveyor table. The needfor

The opinionsexpressed hereinarethoseof the authorsandarenot to be construedasofficialor asreflectingthe viewsof the Departmentof the Navy, the Departmentof the Defense,or the U.S. Government. %ommander,Dental Corps,U.S. Navy; Director, Area Dental Laboratory. bAssociate Professor,ProsthodonticDepartment,Retired. J PROSTHET DENT 1993;69:542-3. 10/4/44470 542

Fig.

1. Surveyor ball machined to fit the mounting ring.

VOLUME

69

NUMBER

6

GARDNER.

PARR,

AND

GOLDMAN

a surveyor table can be eliminated by a new ball machined and threaded to fit the mounting ring (Fig. 1). The gain of vertical space makes it easier to do the work, especially when attachments are being used (Fig. 2). Any competent machine shop can make this part if supplied with a regular ball and mounting ring. Because the threads in mounting rings are not standardized, a threaded ball is required for each type of ring used. REFERENCE 1.

Schmitt SM, Huff TL, Trehilcock CF. A nlodihed survey table mounted casts.J PROSTHEYDENT 1983:49:8fil.

Reprint

requests

fw

to:

CDRR.W.TOTH,DC,USN DIRECTOR,AREADENTAL LABORATORY NAVAL DENTAL CENTER NORFOLK, VA 23511.6295

Fig. 2. Mounted cast on the surveyor.

Vinyl

polysiloxane

flasking

of an ocular

L. Kirk Gardner, DDS,* Gregory R. Parr, DDS,b and Barry Medical College of Georgia, School of Dentistry, Augusta, Ga. The frontal surface of an ocular prosthesis may be flasked with the use of vinylpolysiloxane (VPS) putty to reduce work during the laboratory phase of ocular prosthesis construction.l The following technique is suggested. 1. Prepare the wax ocular blank with the iris button positioned ready for flasking. Place VPS putty on the frontal surface of the wax-up (with intentional undercuts placed into the putty), and allow it to set (Fig. 1). 2. Half-flask the prosthesisand putty in stone. After setting, apply separating medium (Coe-Sep, Coe Laboratories, Chicago, Ill.). 3. Pour the secondportion of the flask and allow it to set. 4. Separate the flask, remove the wax, and coat the VPS with a separating medium (Coe-Sep). 5. Mix, pack, and processheat polymerized acrylic resin (White Sclera Resin, EsschemCo., Essington, Pa.). 6. Remove the prosthesisfrom the flask. Relieve the frontal surface and characterize the scleral section (Fig. 2).

aAssociate Professor, Department of Prosthodontics. bProfessor, Department of Prosthodontics. J P~o~~~~~D~~~1993;69:543-4. 0022-3913/93/$1.00+.10. 1014/26178

MAY

1993

prosthesis

M. Goldman, DDSb

7. After characterization, partially fill the frontal portion of the mold with clear heat-polymerized acrylic resin (Clear Acrylic Resin, EsschemCo.) and trial pack with the ocular prosthesisin place.Without the VPS section,

Fig. 1. Vinylpolysiloxane putty adapted to frontal surface of ocular prosthesis.Undercuts are placed into putty. 543