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Refining hollow obturator base using light-activated resin
Refining hollow obturator base using light-activated resin Russell R. Wang, DDS, M S D , a and Robert F. Hirsch, D D S b
School of Dentistry, CaseWestern Reserve University, Cleveland, Ohio The disadvantages of an open-type hollow obturator include difficulty in polishing and cleaning of the internal surface, food accumulation in the hollow obturator and inability to obtain support from the superior aspect in the defect area. This article describes an easy time-saving procedure that uses visible light-activated denture base materials as a reline material to close an open type interim obturator. This procedure can be used successfully for both late stage interim obturators and/or for correcting leakage problems for patients who wear definitive obturators. (J Prosthet Dent 1997;78:327-9.)
The use o f visible light-cured (VLC) denture base materials provides innovative methods o f denture relining and easy fabrication o f maxillofacial prostheses.l-8 Effective obturation o f maxillary defects produces sufficient separation o f the oral and nasal cavity to improve the quality and intelligibility o f speech. Effective obturation will also enhance mastication and deglutition. The weight o f a maxillary obturator prosthesis is often a factor in retention, so it is desirable to design an obturator prosthesis in the form o f a hollow extension. An interim obturator prosthesis needs to be relined or modified periodically after ablative surgery because o f the continuous remodeling, fibrosis, and scar formation during the healing process. Soft tissue and teeth on the remaining maxillary arch serve as important indexes for the obturator base relining. An open-type hollow obturator base is a c o m m o n design for an interim prosthesis, and it is easy to add reline material to its base and remove excess material from its lateral wall. The disadvantages of an open-type hollow obturator include difficulty in polishing and cleaning the internal surface, saliva, mucous crusts, food accumulation in the hollow obturator, and the inability to obtain support from the superior aspect in the defect area. The following procedure describes a simple m e t h o d to reline and close an open-type interim obturator in the surgical defect area should the interim obmrator need to be converted into a definitive obturator prosthesis.
Fig. 1. Stone cast with interim obturator relined with soft reline material.
5. 6.
PROCEDURE
1. Reline the tissue side o f the interim obturator base with chairside soft reline material, which will act as an impression material. 2. Lubricate the remainder of the acrylic resin base o f the obturator with a thin layer o f petroleum jelly. 3. Box the relined obturator with a 2% inch in height adhesive paper (Nacs Corp., Oberlin, Ohio). 4. Pour the cast for the tissue surface o f the obturator ~Assistant Professor, Department of Restorative Dentistry. bAssistantProfessorand Director, Undergraduate Preceptor Program. SEPTEMBER 1997
7.
8.
with fast set stone mixed with plaster at 1 to 1 ratio (Fig. 1). Separate the obturator carefully fi'om the worldng cast. Remove soft reline material from the obturator prosthesis and lubricate the obturator base and the stone cast with petroleum jelly (Fig. 2). Place a thin layer o f denture reline VLC resin (Triad, Dentsply International Inc., York, Pa.) in the surgical defect area on the stone cast where the soft reline material used to be. VLC resin stops right at the edge o f the defect area on the stone cast. Trim a thin layer o f the acrylic resin, in the area adjacent to the obturator base of the original prosthesis to make r o o m for new reline junction. Coat the prosthesis with a water soluble liquid form of separator (Liqui-Foil, American Dental Supply Inc., Easton, Pa.). THE JOURNAL OF PROSTHETIC DENTISTRY
327
THE JOURNAL OF PROSTHETIC DENTISTRY
WANG A N D HIRSCH
Fig. 2. Interim obturator separated from working cast and re-
line material removed. Fig. 4. Adjustment between obturator base and old prosthesis. Original prosthesis seats completely on stone cast in unrefined area.
Fig. 3. New obturator base cured on cast. One third of cast in posterior area was cut off for ease of obturator base removal.
Fig. 5. Completion of refined and sealed obturator base. 9. Place the prosthesis back on the cast that has the uncured VLC resin. Seat the prosthesis until it meets the stone model in the nonrelining area. Trim away any excess uncured VLC resin that might have been expressed during seating in the relieved denture area. [This untouched area acts as an index during this repositioning onto the stone model. ] i0. Remove the obturator prosthesis from the stone cast leaving the uncured VLC material on the cast. 11. Cure the VLC resin on the stone cast in the lightcuring unit for 8 minutes. 12. Cut one third o f the stone in the surgical defect area to ensure the cured VLC resin can be removed from the cast. Reassemble the obturator VLC cured base and the stone cast (Fig. 3). 13. Put the obturator back on the stone cast and slightly adjust the obturator base to completely seat original prosthesis on the stone cast in the unrefined area (Fig. 4). 14. Pick up the VLC resin obturator base with the origi328
nal prosthesis using a few drops o f acrylic adhesive (Sanford Corp., Bcllwood, Ill.) placed in the areas where they interface each other. 15. Fill the gaps between the original prosthesis and the new obturator base with a thin layer o f VLC denture reline resin diluted with chemically cured acrylic resin monomcr. The junctional areas, which were luted to thc new base with acrylic resin adhesive, arc also covered by a thin and diluted layer o f VLC resin to ensure against microleakage in those areas. Place the new assembly in a light-curing unit for 8 minutes. 16. Finish and polish the hollow obturator according to conventional methods (Fig. 5). SUMMARY An easy and time-saving procedure to reline and to close an open-type interim obturator using VLC resin has been described. This procedure can be used for both VOLUME 78 NUMBER 3
WANG AND HIRSCH
THE JOURNAL OF PROSTHETIC DENTISTRY
a late stage interim obturator a n d / o r to correct leaking problems for patients who wear definitive obturators.
7. CaputoTL, Ryan JE.An easy, fast technique for making immediate surgical obturators. J Prosthet Dent 1989;61:473-5. 8. Benington [C. Light-cured hollow obturators. J Prosthet Dent 1989;62:3225.
REFERENCES 1. Fellman S.Visible light-cured denture base resin used in making dentures with conventional teeth. J Prosthet Dent 1989;62:356-9. 2. ShilmanA. Clinical applications of visible light-cured resin in maxillofacial prosthetics. Part I: denture base and reline material J Prosthet Dent 1990;64:578-82. 3. Knudson RC, Williams EO. Radiographical[y detectable intraoral radiation stent. J Prosthet Dent 1989;61:1-3. 4. Khan Z. Soft palate obturator prosthesis made with visible light-cured resin. J Prosthet Dent 1989;62:671-3. 5. Fischman B.The use of light-cured material for immediate hollow obturator prosthesis. J Prosthet Dent 1989;61:215-6. 6. MeyerJB Jr, Knudson RC, Myers KM. Light-cured interim palatal augmentation prosthesis.A clinical report. J Prosthet Dent 1990;63:1-3.
N o t e w o r t h y Abstracts of the Current Literature
Reprint requests to: DR. RUSSELLWANG CAEEWESTERN RESERVEUNIVERSITY SCHOOLOF DENTISTRY DEPARTMENTOF RESTORATWEDENTISTRY 10900 EUCLIDAVE. CLEVELAND, OH 44106
Copyright © 1997 by The Editorial Council of The journal of Prosthetic Dentistry. 0022-3913/97/$5.00 + O. 10/1/83935
Bonding to intact dentin Nakabayashi N, Saimi Y. JDent Res 1996;75:1706-15.
Purpose. It has been reported that dentin bonding may be adversely affected by the presence of a smear layer. Removal of this layer by an acid demineralizing solution before bonding has resulted in higher bond strengths. There is concern that dentinal etching may result in collapse of exposed collagen fibers. This study examined the possibility of bonding to non-demineralized, smear layer-free dentin by use of a self-etching primer. Different priming times were also examined for the development of hybrid layers in the experimental dentin surfaces. Material and Methods. Dentin surfaces were prepared on extracted bovine teeth. These surfaces were then polished for 30 seconds with hydroxyapatite paste, washed, and finally placed in 10 ° C deionized water in an ultrasonic cleaner for 30 minutes. The exposed dentin of the specimens was primed with a solution of 20% 2-methacryloyloxyethyl phenyl phosphoric acid and 30% 2hydroxyethyl methacrylate (20P-30G) for either O, 30, or 60 seconds. The 0 second specimens comprised the control group. These specimens received only photopolymerizing bonding agent without application of primer. The 30- and 60-second primed specimens were subjected to primer application followed by the application of bonding agent. A composite was placed onto the applied bonding agent and then irradiated for 1 minute. Completed specimens were stored in room temperature air for 30 minutes, and were then placed in a 37 ° C water bath for 24 hours. Five specimens from each group were subjected to tensile testing. The gathered data were analyzed with a one-way Neuman-Keuls test ("alpha" = 0.05). Three specimens from each treatment time were cross-sectioned and examined under a scanning electron microscope (SEM). In addition, three specimens from each group were cross sectioned, not embedded in epoxy, and subsequently examined under a transmission electron microscope (TEM). Results. Tensile bond strength (TBS) increased with increased priming times. The mean TBS of the 30-second specimens was similar to that of the 60-second specimens. However, significant difference was found between the 0-second group and the other groups. A significant difference existed among the groups for hybrid layer thicl~ess (0-second specimens exhibited the thinnest and 60-second specimens exhibited the thickest). SEM of the dentin sides after tensile failure showed mostly adhesive failures of the 0-second specimens. Cohesive failures within the composite wcre noted in the other two groups. Specimens in 30- and 60-second groups resisted HC1 demineralization and collagen decomposition by NaOC1. Conclusions. Treating dentin, topically, with 20P-30H effectively creates diffusion channels surrounding collagen channels in preparcd and "polished" bovine dentin. The hybrid layer created in this dentin was not defective and stable bonding was promoted. 53 references.--DL Dixon
SEPTEMBER 1997
329
School of Dentistry, CaseWestern Reserve University, Cleveland, Ohio The disadvantages of an open-type hollow obturator include difficulty in polishing and cleaning of the internal surface, food accumulation in the hollow obturator and inability to obtain support from the superior aspect in the defect area. This article describes an easy time-saving procedure that uses visible light-activated denture base materials as a reline material to close an open type interim obturator. This procedure can be used successfully for both late stage interim obturators and/or for correcting leakage problems for patients who wear definitive obturators. (J Prosthet Dent 1997;78:327-9.)
The use o f visible light-cured (VLC) denture base materials provides innovative methods o f denture relining and easy fabrication o f maxillofacial prostheses.l-8 Effective obturation o f maxillary defects produces sufficient separation o f the oral and nasal cavity to improve the quality and intelligibility o f speech. Effective obturation will also enhance mastication and deglutition. The weight o f a maxillary obturator prosthesis is often a factor in retention, so it is desirable to design an obturator prosthesis in the form o f a hollow extension. An interim obturator prosthesis needs to be relined or modified periodically after ablative surgery because o f the continuous remodeling, fibrosis, and scar formation during the healing process. Soft tissue and teeth on the remaining maxillary arch serve as important indexes for the obturator base relining. An open-type hollow obturator base is a c o m m o n design for an interim prosthesis, and it is easy to add reline material to its base and remove excess material from its lateral wall. The disadvantages of an open-type hollow obturator include difficulty in polishing and cleaning the internal surface, saliva, mucous crusts, food accumulation in the hollow obturator, and the inability to obtain support from the superior aspect in the defect area. The following procedure describes a simple m e t h o d to reline and close an open-type interim obturator in the surgical defect area should the interim obmrator need to be converted into a definitive obturator prosthesis.
Fig. 1. Stone cast with interim obturator relined with soft reline material.
5. 6.
PROCEDURE
1. Reline the tissue side o f the interim obturator base with chairside soft reline material, which will act as an impression material. 2. Lubricate the remainder of the acrylic resin base o f the obturator with a thin layer o f petroleum jelly. 3. Box the relined obturator with a 2% inch in height adhesive paper (Nacs Corp., Oberlin, Ohio). 4. Pour the cast for the tissue surface o f the obturator ~Assistant Professor, Department of Restorative Dentistry. bAssistantProfessorand Director, Undergraduate Preceptor Program. SEPTEMBER 1997
7.
8.
with fast set stone mixed with plaster at 1 to 1 ratio (Fig. 1). Separate the obturator carefully fi'om the worldng cast. Remove soft reline material from the obturator prosthesis and lubricate the obturator base and the stone cast with petroleum jelly (Fig. 2). Place a thin layer o f denture reline VLC resin (Triad, Dentsply International Inc., York, Pa.) in the surgical defect area on the stone cast where the soft reline material used to be. VLC resin stops right at the edge o f the defect area on the stone cast. Trim a thin layer o f the acrylic resin, in the area adjacent to the obturator base of the original prosthesis to make r o o m for new reline junction. Coat the prosthesis with a water soluble liquid form of separator (Liqui-Foil, American Dental Supply Inc., Easton, Pa.). THE JOURNAL OF PROSTHETIC DENTISTRY
327
THE JOURNAL OF PROSTHETIC DENTISTRY
WANG A N D HIRSCH
Fig. 2. Interim obturator separated from working cast and re-
line material removed. Fig. 4. Adjustment between obturator base and old prosthesis. Original prosthesis seats completely on stone cast in unrefined area.
Fig. 3. New obturator base cured on cast. One third of cast in posterior area was cut off for ease of obturator base removal.
Fig. 5. Completion of refined and sealed obturator base. 9. Place the prosthesis back on the cast that has the uncured VLC resin. Seat the prosthesis until it meets the stone model in the nonrelining area. Trim away any excess uncured VLC resin that might have been expressed during seating in the relieved denture area. [This untouched area acts as an index during this repositioning onto the stone model. ] i0. Remove the obturator prosthesis from the stone cast leaving the uncured VLC material on the cast. 11. Cure the VLC resin on the stone cast in the lightcuring unit for 8 minutes. 12. Cut one third o f the stone in the surgical defect area to ensure the cured VLC resin can be removed from the cast. Reassemble the obturator VLC cured base and the stone cast (Fig. 3). 13. Put the obturator back on the stone cast and slightly adjust the obturator base to completely seat original prosthesis on the stone cast in the unrefined area (Fig. 4). 14. Pick up the VLC resin obturator base with the origi328
nal prosthesis using a few drops o f acrylic adhesive (Sanford Corp., Bcllwood, Ill.) placed in the areas where they interface each other. 15. Fill the gaps between the original prosthesis and the new obturator base with a thin layer o f VLC denture reline resin diluted with chemically cured acrylic resin monomcr. The junctional areas, which were luted to thc new base with acrylic resin adhesive, arc also covered by a thin and diluted layer o f VLC resin to ensure against microleakage in those areas. Place the new assembly in a light-curing unit for 8 minutes. 16. Finish and polish the hollow obturator according to conventional methods (Fig. 5). SUMMARY An easy and time-saving procedure to reline and to close an open-type interim obturator using VLC resin has been described. This procedure can be used for both VOLUME 78 NUMBER 3
WANG AND HIRSCH
THE JOURNAL OF PROSTHETIC DENTISTRY
a late stage interim obturator a n d / o r to correct leaking problems for patients who wear definitive obturators.
7. CaputoTL, Ryan JE.An easy, fast technique for making immediate surgical obturators. J Prosthet Dent 1989;61:473-5. 8. Benington [C. Light-cured hollow obturators. J Prosthet Dent 1989;62:3225.
REFERENCES 1. Fellman S.Visible light-cured denture base resin used in making dentures with conventional teeth. J Prosthet Dent 1989;62:356-9. 2. ShilmanA. Clinical applications of visible light-cured resin in maxillofacial prosthetics. Part I: denture base and reline material J Prosthet Dent 1990;64:578-82. 3. Knudson RC, Williams EO. Radiographical[y detectable intraoral radiation stent. J Prosthet Dent 1989;61:1-3. 4. Khan Z. Soft palate obturator prosthesis made with visible light-cured resin. J Prosthet Dent 1989;62:671-3. 5. Fischman B.The use of light-cured material for immediate hollow obturator prosthesis. J Prosthet Dent 1989;61:215-6. 6. MeyerJB Jr, Knudson RC, Myers KM. Light-cured interim palatal augmentation prosthesis.A clinical report. J Prosthet Dent 1990;63:1-3.
N o t e w o r t h y Abstracts of the Current Literature
Reprint requests to: DR. RUSSELLWANG CAEEWESTERN RESERVEUNIVERSITY SCHOOLOF DENTISTRY DEPARTMENTOF RESTORATWEDENTISTRY 10900 EUCLIDAVE. CLEVELAND, OH 44106
Copyright © 1997 by The Editorial Council of The journal of Prosthetic Dentistry. 0022-3913/97/$5.00 + O. 10/1/83935
Bonding to intact dentin Nakabayashi N, Saimi Y. JDent Res 1996;75:1706-15.
Purpose. It has been reported that dentin bonding may be adversely affected by the presence of a smear layer. Removal of this layer by an acid demineralizing solution before bonding has resulted in higher bond strengths. There is concern that dentinal etching may result in collapse of exposed collagen fibers. This study examined the possibility of bonding to non-demineralized, smear layer-free dentin by use of a self-etching primer. Different priming times were also examined for the development of hybrid layers in the experimental dentin surfaces. Material and Methods. Dentin surfaces were prepared on extracted bovine teeth. These surfaces were then polished for 30 seconds with hydroxyapatite paste, washed, and finally placed in 10 ° C deionized water in an ultrasonic cleaner for 30 minutes. The exposed dentin of the specimens was primed with a solution of 20% 2-methacryloyloxyethyl phenyl phosphoric acid and 30% 2hydroxyethyl methacrylate (20P-30G) for either O, 30, or 60 seconds. The 0 second specimens comprised the control group. These specimens received only photopolymerizing bonding agent without application of primer. The 30- and 60-second primed specimens were subjected to primer application followed by the application of bonding agent. A composite was placed onto the applied bonding agent and then irradiated for 1 minute. Completed specimens were stored in room temperature air for 30 minutes, and were then placed in a 37 ° C water bath for 24 hours. Five specimens from each group were subjected to tensile testing. The gathered data were analyzed with a one-way Neuman-Keuls test ("alpha" = 0.05). Three specimens from each treatment time were cross-sectioned and examined under a scanning electron microscope (SEM). In addition, three specimens from each group were cross sectioned, not embedded in epoxy, and subsequently examined under a transmission electron microscope (TEM). Results. Tensile bond strength (TBS) increased with increased priming times. The mean TBS of the 30-second specimens was similar to that of the 60-second specimens. However, significant difference was found between the 0-second group and the other groups. A significant difference existed among the groups for hybrid layer thicl~ess (0-second specimens exhibited the thinnest and 60-second specimens exhibited the thickest). SEM of the dentin sides after tensile failure showed mostly adhesive failures of the 0-second specimens. Cohesive failures within the composite wcre noted in the other two groups. Specimens in 30- and 60-second groups resisted HC1 demineralization and collagen decomposition by NaOC1. Conclusions. Treating dentin, topically, with 20P-30H effectively creates diffusion channels surrounding collagen channels in preparcd and "polished" bovine dentin. The hybrid layer created in this dentin was not defective and stable bonding was promoted. 53 references.--DL Dixon
SEPTEMBER 1997
329