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Dental Acrylic Implant for Use in Evisceration or Enucleation of the Eyeball
NOTES, CASES, INSTRUMENTS DENTAL ACRYLIC IMPLANT FOR USE IN EVISCERATION OR ENUCLEATION O F T H E EYEBALL SQUADRON LEADER M. W.
NUGENT*
Winnipeg, Manitoba, Canada
Dental acrylic is an easily obtainable and inexpensive eye implant that can be used after eviscerations or enucleations of the eyeball where an implant is desirable. In recent years it has become increasingly difficult to obtain satisfactory implants, with the result that many eye sockets are not receiving the cosmetic benefit which an implant affords.
2), by the use of dental stone, only two fifths of each implant being embedded. When the dental stone has set, the exposed wax surfaces are covered with tinfoil one one thousandth of an inch in thickness. All wrinkles must be carefully ironed out. This foil is shown in figure 11, and is
METHOD
In making spherical eye implants from dental acrylic (methylmethacrylate res-
Figs. 1-3 (Nugent). Sizes of implants and embedding in denture flask.
in), the implants are first formed from dental base plate wax in the desired range of sizes as shown in figure 1. An adequate size range includes those varying in diameter from 8 to 20 mm., in 2-mm. differences; namely 8, 10, 12, 14, 16, 18, and 20. These are then invested in the bottom half of a denture flask (fig. * Consultant Ophthalmologist, No. 2 R.M.B., Deer Lodge Military Hospital.
Figs. 4-12 (Nugent). Equipment for making implant.
identical with that used in processing acrylic dentures. The exposed stone surface is now painted with a separating medium, and the top half of the denture flask filled with dental stone. Formation of air bubbles is avoided by carefully vibrating the flask. When this has set, the denture flask is placed in boiling water for 10 minutes. The flask is then opened, and the wax boiled out, after which the flask is allowed to cool and the acrylic is packed. To prepare the acrylic, 9 c.c. of monomer (liquid), as shown in figure 6, is poured into a mixing jar such as that seen in figure 7. A powder measure is used to add four portions of polymer (powder, fig. 5) to the monomer. If a powder measure is not available add polymer (powder) slightly in excess of the amount required to absorb the 9 c.c. of monomer (liquid). The mixing jar is covered and allowed to stand for five minutes, after which the contents are thoroughly mixed
462
NOTES, CASES, INSTRUMENTS
with a stainless steel spatula (fig. 12) until the color is incorporated. The cover is again placed on the mixing jar, and it is allowed to stand until the mixture can be removed as a "putty-like" mass. This will require about 20 minutes, depending on the temperature of the room and the mixture. This mixture (dental acrylic) is sufficient to make a set of seven eye implants ranging in diameter from 8 to 20 mm., in 2-mm. differences. The acrylic is now packed firmly into the top half of the denture flask, which represents three fifths of each implant. The acrylic is piled up sufficiently so that it will fill the bottom half of the denture flask, which represents two fifths of each implant. A sheet of wet cellophane (fig. 10) is placed over the acrylic and the two halves of the denture flask are brought together. Slow and even pressure is then applied to the packed denture flask by means of a pressure clamp or dental press. This allows any excess acrylic to escape. When the flask is completely closed it is removed from the press and opened. The cellophane is stripped off and the surplus acrylic cut away. Fresh acrylic is now added to each implant, the wet cellophane again placed in position, and the pressing procedure repeated. This is necessary in order to expel any air bubbles that may have been trapped in the acrylic and not entirely expelled by the first press. The flask is again removed from the press and opened, the cellophane stripped off, and the surplus acrylic cut away. The next step is to line the implant impressions in the bottom half of the flask with tinfoil, close it, and return it to the press. It is now ready for curing. The method herein outlined can be used in making implants from clear or pink acrylic. A simpler method exists if implants of pink acrylic only are desired. In this instance solutions of waterglass may
be used in place of the tinfoil and cellophane. When the wax is boiled out and while the case is still hot, both halves of the implant impressions are coated liberally with waterglass solution number one (fig. 4 ) , which consists of one part waterglass to six parts of water. This is allowed to stand for two to three minutes, then the excess is wiped away and waterglass solution number two (fig. 4 ) , which is made up of two parts of waterglass to one part of water is applied. When the flask is cold and ready to pack with pink acrylic, the waterglass will be dry and glazed. It is a matter of individual choice whether clear or pink acrylic implants are used, as one has no advantage over the other. However, because of the simpler and quicker method that can be employed in making implants of pink acrylic, this has become the writer's choice. The final two steps are those of curing and finishing. The curing of the acrylic must be done by the slow method. To do this the flask is completely covered in water of room temperature, placed over a slow heat, and one hour allowed to bring it to 162°F. It is then held at that temperature for four hours, following which the flask is removed from the bath and bench cooled for approximately one hour. The implants are then dug out and finished off. The finishing is done by first removing the ring of surplus acrylic with a fine emery band on an arbor chuck and then polishing with a soft cotton buff and fine pumice, followed by a clean buff and whiting. DISCUSSION
Almost all eviscerations or enucleations of the eyeball should be followed by some form of implant within the sclera or Tenon's capsule, as the case may be. The only real contraindication to such a procedure is the presence of infection, mak-
NOTES, CASES, INSTRUMENTS ing adequate open drainage a surgical necessity. Because of the difficulty in obtaining satisfactory implants many eyes are being removed and no implant used. This is a decided disadvantage to a good cosmetic result, for it permits more sinking-in of the periorbital and peribulbar tissues. Another factor in favor of the use of an implant is that it gives a better bed on which the artificial eye can rotate and to a greater extent helps lessen the stariness of an artificial eye that rotates too little or not at all. Bone, cartilage, or fat implants can be discarded as inadequate. Gold, platinum, tantalum, or vitalium implants, although excellent, are both expensive and, for the past few years, almost impossible to obtain. Mules's spheres are hollow, occasionally break in situ, and are also difficult to obtain. The solid glass ball is not to be recommended because of its weight, which increases the possibility of postoperative extrusion. Implants made of dental acrylic (methylmethacrylate resin) have no apparent disadvantages in that they are inexpensive, easily obtainable, light in weight, and well tolerated by the soft tissues of the orbit. To date the writer has had no extrusions or allergies with this type of implant. In conjunction with the use of dental acrylic implants, accepted surgical mediods were used. In enucleations, Tenon's capsule and the extraocular muscles were overlapped in front of the implant, 00chromic catgut being used, and the conjunctival layer closed separately with 00-plain catgut. In eviscerations, the scleral tissue was overlapped in front of the implant, again with the use of 00chromic catgut, and Tenon's capsule and conjunctiva were closed separately with 00-plain catgut. Following these clo-
463
sures 5-percent sodium sulfathiazole ointment was applied, and a pressure bandage placed in all cases. The pressure bandage was not disturbed for seven days, but reinforced when indicated. All implants of dental acrylic used were spherical in shape. Bizarre shapes were not considered, since it has been shown that the spherical shape is adequate. The size of the dental acrylic sphere to be used in each case is important. The largest spherical implant that Tenon's capsule, or the sclera, will hold without tension and allowing for adequate overlapping of tissues should be used in all cases. For this purpose sizes ranging in diameter from 8 to 20 mm., in 2-mm. differences, should be kept at hand. SUMMARY AND CONCLUSIONS
1. The method of making eye implants from dental acrylic has been outlined. This is only a variation in the everyday work of a dental technician and is not necessarily original. 2. They can be obtained easily and inexpensively from any dental laboratory. 3. They replace adequately all other types of implants. 4. To date, no contraindications of their use have arisen. 5. The size of dental acrylic implant to be used is important, and the use of a pressure bandage is to be stressed. Acknowledgment. The author wishes to thank Warrant Officer W. J. Mitchell of the Canadian Dental Corps, for carrying out the details of technique in the making of these implants, and for keeping our supply adequate during the past two years. 1930 WUshire Boulevard Los Angeles 5
NUGENT*
Winnipeg, Manitoba, Canada
Dental acrylic is an easily obtainable and inexpensive eye implant that can be used after eviscerations or enucleations of the eyeball where an implant is desirable. In recent years it has become increasingly difficult to obtain satisfactory implants, with the result that many eye sockets are not receiving the cosmetic benefit which an implant affords.
2), by the use of dental stone, only two fifths of each implant being embedded. When the dental stone has set, the exposed wax surfaces are covered with tinfoil one one thousandth of an inch in thickness. All wrinkles must be carefully ironed out. This foil is shown in figure 11, and is
METHOD
In making spherical eye implants from dental acrylic (methylmethacrylate res-
Figs. 1-3 (Nugent). Sizes of implants and embedding in denture flask.
in), the implants are first formed from dental base plate wax in the desired range of sizes as shown in figure 1. An adequate size range includes those varying in diameter from 8 to 20 mm., in 2-mm. differences; namely 8, 10, 12, 14, 16, 18, and 20. These are then invested in the bottom half of a denture flask (fig. * Consultant Ophthalmologist, No. 2 R.M.B., Deer Lodge Military Hospital.
Figs. 4-12 (Nugent). Equipment for making implant.
identical with that used in processing acrylic dentures. The exposed stone surface is now painted with a separating medium, and the top half of the denture flask filled with dental stone. Formation of air bubbles is avoided by carefully vibrating the flask. When this has set, the denture flask is placed in boiling water for 10 minutes. The flask is then opened, and the wax boiled out, after which the flask is allowed to cool and the acrylic is packed. To prepare the acrylic, 9 c.c. of monomer (liquid), as shown in figure 6, is poured into a mixing jar such as that seen in figure 7. A powder measure is used to add four portions of polymer (powder, fig. 5) to the monomer. If a powder measure is not available add polymer (powder) slightly in excess of the amount required to absorb the 9 c.c. of monomer (liquid). The mixing jar is covered and allowed to stand for five minutes, after which the contents are thoroughly mixed
462
NOTES, CASES, INSTRUMENTS
with a stainless steel spatula (fig. 12) until the color is incorporated. The cover is again placed on the mixing jar, and it is allowed to stand until the mixture can be removed as a "putty-like" mass. This will require about 20 minutes, depending on the temperature of the room and the mixture. This mixture (dental acrylic) is sufficient to make a set of seven eye implants ranging in diameter from 8 to 20 mm., in 2-mm. differences. The acrylic is now packed firmly into the top half of the denture flask, which represents three fifths of each implant. The acrylic is piled up sufficiently so that it will fill the bottom half of the denture flask, which represents two fifths of each implant. A sheet of wet cellophane (fig. 10) is placed over the acrylic and the two halves of the denture flask are brought together. Slow and even pressure is then applied to the packed denture flask by means of a pressure clamp or dental press. This allows any excess acrylic to escape. When the flask is completely closed it is removed from the press and opened. The cellophane is stripped off and the surplus acrylic cut away. Fresh acrylic is now added to each implant, the wet cellophane again placed in position, and the pressing procedure repeated. This is necessary in order to expel any air bubbles that may have been trapped in the acrylic and not entirely expelled by the first press. The flask is again removed from the press and opened, the cellophane stripped off, and the surplus acrylic cut away. The next step is to line the implant impressions in the bottom half of the flask with tinfoil, close it, and return it to the press. It is now ready for curing. The method herein outlined can be used in making implants from clear or pink acrylic. A simpler method exists if implants of pink acrylic only are desired. In this instance solutions of waterglass may
be used in place of the tinfoil and cellophane. When the wax is boiled out and while the case is still hot, both halves of the implant impressions are coated liberally with waterglass solution number one (fig. 4 ) , which consists of one part waterglass to six parts of water. This is allowed to stand for two to three minutes, then the excess is wiped away and waterglass solution number two (fig. 4 ) , which is made up of two parts of waterglass to one part of water is applied. When the flask is cold and ready to pack with pink acrylic, the waterglass will be dry and glazed. It is a matter of individual choice whether clear or pink acrylic implants are used, as one has no advantage over the other. However, because of the simpler and quicker method that can be employed in making implants of pink acrylic, this has become the writer's choice. The final two steps are those of curing and finishing. The curing of the acrylic must be done by the slow method. To do this the flask is completely covered in water of room temperature, placed over a slow heat, and one hour allowed to bring it to 162°F. It is then held at that temperature for four hours, following which the flask is removed from the bath and bench cooled for approximately one hour. The implants are then dug out and finished off. The finishing is done by first removing the ring of surplus acrylic with a fine emery band on an arbor chuck and then polishing with a soft cotton buff and fine pumice, followed by a clean buff and whiting. DISCUSSION
Almost all eviscerations or enucleations of the eyeball should be followed by some form of implant within the sclera or Tenon's capsule, as the case may be. The only real contraindication to such a procedure is the presence of infection, mak-
NOTES, CASES, INSTRUMENTS ing adequate open drainage a surgical necessity. Because of the difficulty in obtaining satisfactory implants many eyes are being removed and no implant used. This is a decided disadvantage to a good cosmetic result, for it permits more sinking-in of the periorbital and peribulbar tissues. Another factor in favor of the use of an implant is that it gives a better bed on which the artificial eye can rotate and to a greater extent helps lessen the stariness of an artificial eye that rotates too little or not at all. Bone, cartilage, or fat implants can be discarded as inadequate. Gold, platinum, tantalum, or vitalium implants, although excellent, are both expensive and, for the past few years, almost impossible to obtain. Mules's spheres are hollow, occasionally break in situ, and are also difficult to obtain. The solid glass ball is not to be recommended because of its weight, which increases the possibility of postoperative extrusion. Implants made of dental acrylic (methylmethacrylate resin) have no apparent disadvantages in that they are inexpensive, easily obtainable, light in weight, and well tolerated by the soft tissues of the orbit. To date the writer has had no extrusions or allergies with this type of implant. In conjunction with the use of dental acrylic implants, accepted surgical mediods were used. In enucleations, Tenon's capsule and the extraocular muscles were overlapped in front of the implant, 00chromic catgut being used, and the conjunctival layer closed separately with 00-plain catgut. In eviscerations, the scleral tissue was overlapped in front of the implant, again with the use of 00chromic catgut, and Tenon's capsule and conjunctiva were closed separately with 00-plain catgut. Following these clo-
463
sures 5-percent sodium sulfathiazole ointment was applied, and a pressure bandage placed in all cases. The pressure bandage was not disturbed for seven days, but reinforced when indicated. All implants of dental acrylic used were spherical in shape. Bizarre shapes were not considered, since it has been shown that the spherical shape is adequate. The size of the dental acrylic sphere to be used in each case is important. The largest spherical implant that Tenon's capsule, or the sclera, will hold without tension and allowing for adequate overlapping of tissues should be used in all cases. For this purpose sizes ranging in diameter from 8 to 20 mm., in 2-mm. differences, should be kept at hand. SUMMARY AND CONCLUSIONS
1. The method of making eye implants from dental acrylic has been outlined. This is only a variation in the everyday work of a dental technician and is not necessarily original. 2. They can be obtained easily and inexpensively from any dental laboratory. 3. They replace adequately all other types of implants. 4. To date, no contraindications of their use have arisen. 5. The size of dental acrylic implant to be used is important, and the use of a pressure bandage is to be stressed. Acknowledgment. The author wishes to thank Warrant Officer W. J. Mitchell of the Canadian Dental Corps, for carrying out the details of technique in the making of these implants, and for keeping our supply adequate during the past two years. 1930 WUshire Boulevard Los Angeles 5