INTERNALESCAPECHANNELONCERAMICCROWNS
strength of the castable ceramic crown. This suggested that an internal escape channel was indicated for posterior Dicar castable ceramic crowns.
10. Tjan AHL, Sarkissian R. Internal escape channel: an alternative to venting complete crowns. J PROSTHET DENT 19&1;52:50-6. 11. Dicer Research Report. ~012. issue 1. February 1986. Dentsply International Inc., York, Pa. 12. Malament KA, Grossman DG. The cast glass-ceramic restoration. J PROSTIXEF DENT 1987;57:674-83.
REFERENCES 1. Phillips RW. Skinner’s science of dental materials. 8th ed. Philadelphia: WB Saunders Co, 1981:463-4,510-X 2. Eames WB, O’Neal SJ, Monteiro J, Miller C, Roan JD Jr, Cohen KS. Techniques to improve the seating of castings. J Am Dent Assoc 1978;96:432-7.
3. Cooper TM, Christensen GJ, Laswell HR, Baster R. Effect of venting on cast gold full crowns. J PROSTHET DENT 1971;26:621-6. 4. Meyers GE. DOSand don’ts for three dental luting cements. J Am Dent Assoc 1978;97:502-4. 5. Tjan AHL, Sarkissian R. Comparison of internal escape channels with die spacing and occlusal venting. J PROSTHET DENT 1985;53:613-7. 6. Tjan AHL, Sarkissian R, Miller GD. Internal escapechannel to improve the seating of full crowns with various marginal configurations: a follow-up study. J PROSTHJST DENT 1985;53:759-62. 7. Webb EL, Murray HV, Holland GA, Taylor DF. Effects of preparation relief and flow channels on seating full coverage castings during cementation. J PROSTHET DENT 1983;49:777-80. 8. Phillips RW. Skinner’s science of dental materials. 8th ed. Philadelphia: WB Saunders Co, 1981:404. 9. Phillips RW. Skinner’s science of dental materials. 8th ed. Philadelphia: WB Saunders Co, 1981:38.
Profilometer, SEM, and visual polishing methods Gary R. Goldstein, D.D.S.,* Bruce R. Barnhard, Bapanaiah Penugonda, D.D.S., M.S.*** New York University,
13. Miller GD, Tjan AHL. The internal escape channel; a solution to incomplete seating of full cast crowns. J Am Dent Assoc 1982;104: 322-4. 14. Rosenstiel SF, Gegauff AG. Improving the cementation of complete cast crowns: a comparison of static and dynamic seating methods. J Am Dent Assoc 1988;117:845-8. 15. Vermilyea SG, Kuffler MJ, Huget EF. The effects of die relief agent on the retention of full coverage castings. J PROSTHET DENT 1983;50:20710.
16. Burkl CE, Ocampo BS. Compressive strengths of a new foil and porcelain-fused-to-metal CIOWIIS. J PROSTHET DENT 1987;57:404-10. 17. Gibbs CH, Mahan PE, Lundeen HC, Brehnan K, Walsh EF, Holbrook WB. Occlusal forces during chewing and swallowing as measured by sound transmission. J PROSTHETDENT 1981;46:443-9. 18. Brukl CE, Philp GK. The fit of molded all-ceramic, twin foil, and conventional ceramic crowns. J PROSTHET DENT 1987;58:408-13. Reprint requests to: DR. KENNETH M. HARRISON 768 SOOTHLEAFDR. VIRGINIA BEACH, VA 23462
assessment
of porcelain
D.D.S.,** and
Kriser Dental Center, New York, N.Y.
Research has indicated that polishing ground porcelain is essential to control the wear of opposing occlusal surfaces and reduce the inflammation of contacted soft tissue. Five popular methods for polishing porcelain were evaluated by use of a profilometer, SEM, and normal vision. Seventy disks, 36 Biobond disks and 36 Ceramco disks, were roughened with a green stone and polished with one of the methods according to the manufacturers’ directions. Brasseler, Dedeco, Dentsply, and Shofu porcelain polishing systems were suitable for restoring ground porcelain. However, clinical evaluations correlated to the profilometer and SEM readings revealed that the Brasseler system was superior for polishing Ceramco porcelain whereas the Den-Mat system was unacceptable. (J PROSTEET DENT 1991;66$27-34.)
T
he use of porcelain as a restorative material has created numerous concerns for the clinician. Unglazed porcelain has been shown to cause unfavorable connective Presented at the Greater New York Academy of Prosthodontics meeting, New York, N.Y. *Professor, Department of Prosthodontics and Occlusion. **Consulting Medical StafF for Prosthodontics, Kessler Institute for Rehabilitation, New York, N.Y. ***Assistant Professor, Department of Comprehensive Care and Applied Practice Administration. 10/l/27941.
THEJOURNAL
OF PROSTHETIC DENTISTRY
tissue responsesl” and increase the potential for wear of opposing occlusal surfaces.4 Whereas the glazed surface is considered the ideal, the realities of the clinical environment dictate that minor alterations to the porcelain be corrected by polishing instead of reglazing. We conducted a survey of the faculty of the Department of Prosthodontics and Occlusion at New York University. Of the 53 responding clinicians, all except one polish minor adjustmenta to the porcelain surface rather than reglaze. The Shofu Porcelain adjustment kit (Shofu Dental Corp., Menlo Park, Calif.) was used by 3’7 members of the faculty,
GOLDSTEIN,
Fig.
Table
BARNHARD,
AND
PENUGONDA
1. SEM of glazed Ceramcoporcelain. (Original magnification X100.)
I. Products used in study
Table
II.
Surface roughnessanalysis of biobond
porcelain Product
Biobondporcelain Ceramcoporcelain DedecoSuperPolish rubberwheels ShofuPorcelain adjustmentkit Den-Mat Diamond/ Porcelainpolishingpaste Brasseler Truluster polishingsystem DentsplyPorcelain finishingkit
DentsplyInternational York, Pa. J & J Dental ProductsCo. EastWindsor,N.J. DedecoInternationalInc. LongEddy, N.Y. ShofuDentalCorp. Menlo Park, Calif. Den-Mat Corp. SantaMaria, Calif BrasselerUSA, Inc. Savannah,Ga. DentsplyInternational
with the remaining 16 divided among numerous other manufacturers. All but four of the responders used the samesystem for porcelain denture teeth. An SEM evaluation of a specific technique for repolishing an adjusted porcelain surface concluded that it appeared similar to the glazed surface.5Schlisselet al.‘j compared 11 techniques for adjusting porcelain denture teeth visually and by scanning electron microscope @EM) to discover that three approacheswere acceptable.An examination of the surface texture of porcelain with SEM after reduction and natural glazing confirmed that prepolishing wasnecessarybefore reglazing.’ Klausner et aLscompared
628
Mean
SD
1
Dedeco Dentsply Brasseler Shofu Den-Mat Brackets enclose Tukey tests.
Ra (pm)
Casts
205.6071 247.3214 264.1071
92.0778 95.0411 85.4866
28 28 28
382.0000]
61.6856
454.60711
84.3513
28 28
statistically
similar
groups
ee determined
by Scheffe
and
four techniques with both SEM and surface analyzer for porcelain polishing versusglazed porcelain without detecting a difference. Bessingand Wiktorssong compared two different porcelain polishing systems by both SEM and profilometer. They reported that the average roughness value (Ras) for the polished surfaceswaslessthan the Ras for the autoglazedsurfaces,but the SEM evaluations demonstrated the opposite result. This study compared the efficacy of five current porcelain polishingprocedureson two different dental porcelains visually, quantitatively with a profilometer, and qualitatively with an SEM.
MATERIAL
AND
METHODS
Thirty-five quarter-sized disks of Biobond (Dentaply International, York, Pa.) and Ceramco (J and J Dental Products, East Windsor, N.J.) porcelain were baked to a medium glaze by the respective manufacturer. One half of
MAY
1991
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66
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PORCELAIN
POLISHING
METHODS
Fig. 2. SEM of Ceramco porcelain finished with Brasseler Truluster (Original magnification X100.)
Table
III.
Surface roughness analysis of Ceramco
Table
porcelain Product
Brasseler Dentsply Dedeco Shofu Den-Mat
Porcelain Mean
Ra (pm)
1
181.9643 222.0714 307.6249 345.5000 500.53577
Brackets enclose statistically Tukey tests.
similar
1
SD 97.4905 111.0619 100.9265 76.6466 120.1692
groups as determined
Casts
28 28 28 28 28 by Sheffe and
each disk was abraded with a No. 120 green stone (Dedeco International Inc., Long Eddy, N.Y.) to simulate a clinical adjustment. The samples, seven per group, were then polished with the products listed in Table I, according to the manufacturers’ recommendations. After they were polished, the samples were cleaned for 10 minutes in a cleaning solution (Healthco International, Boston, Mass.) in an ultrasonic bath (T-14, L & R Mfg. Co., Kearny, N. J.). Surface roughness was recorded at four representative sites on each disk with a Mitutoyo Surftest(Mitutoyo Mfg. Co. Ltd., Tokyo, Japan) profilometer with a cutoff of 0.25 mm and a transverse length of 1.5 mm. Visual evaluations were performed by prosthodontists or dental technicians and the scanning electron micrographs (IS1 Super III A, International Scientific Instruments, Inc., Santa Clara, Calif.) were analyzed.
THE
JOURNAL
IV.
OF PROSTHETIC
DENTISTRY
polishing system.
Clinical evaluations and system
Biobond porcelain (Ranked by 8 evaluators) Shofu Dentsply Brasseler Dedeco Den-Mat*
Ceramco porcelain (Ranked by 7 evaluators) Brasseler Dedecot Dentsply Shofu Den-Mat*
Rank
order
First
place
21 21 19 9 0
4 2 2
35 18 8 1 0
7
votes
*Only Den-Mat was considered clinically unacceptable. tDedeco had a “dirty” looking darkened surface after polishing that could not be removed in ultrasonic bath, all clinicians tended to downgrade it as a result.
The tests performed by the evaluators were designed as a blind study. RESULTS The means of the profilometer tests were presented in Tables II and III. Clinical evaluations are displayed in Table IV, with the polished disks ranked from smoothest to
GOLDSTEIN,
BARNHARD,
AND
PENUGONDA
Fig. 3. SEM of Ceramco porcelain finished with Densply porcelain polishing kit. (Original magnification X100.)
Fig. 4. SEM of Ceramco porcelain finished with Shofu porcelain polishing kit. (Original magnification X100.)
roughest. The evaluators judged shine and smoothness and were also asked tc note any clinically unacceptable samplea. Five points were assigned for first place, three points for second place, one point for third place, and no point for fourth and fifth place. Eight clinical evaluators judged the 630
Shofu system best for Biobond porcelain with 21 points and four first place votes; the Dentaply system ranked next with 21 points and two first place votes, and the Brasseler systern collected 19 points and two first place votes, the Dedeco system received nine points and the Den-Mat system MAY
1901
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PORCELAIN
POLISHING
METHODS
Fig. 5. SEM of glazed Biobond porcelain. (Original magnification
Fig. 6. SEM of Biobond porcelain finished with Brasseler Truluster (Original magnification X100.)
was last without points. For the Ceramco porcelain, seven clinical evaluators rated the Brasseler system superior with 35 points and all seven evaluators awarding a first place vote, the Dedco system with 18 points, the Dentsply system with eight points, and the Shofu systems with one point. THE
JOURNAL
OF PROSTHETIC
DENTISTRY
X100.)
polishing system.
The SEMs (Figs. 1 through 8) were evaluated and ranked as follows: for the Biobond porcelain, the Brasseler systern was considered equal to or better than glazed, followed by the Dedeco, Dentsply, Shofu, and Den-Mat systems. The Ceramco porcelain was ranked: Brasseler, Dentsply, 631
GOLDSTEIN,
BARNHARD,
AND
PENVGONDA
Fig. 7. SEM of Biobond porcelain finished with Dentsply porcelain polishing kit. (Original magnification X100.)
Table
V. Source
Analysis of variance for Biobond porcelain of variation
Main effects Brand Explained Residual Total
Table
VI. Source
Sum
of squares
1204705.543 1204705.543 1204705.543 964962.143 2169667.686
DF
4 4 4 135 139
Mean
square
301176.386 301176.386 301176.386 7147.868 15609.120
F
Significance
42.135 42.135 42.135
of F
0.000 0.000 0.000
Analysis of variance for Ceramco porcelain of variation
Main effects Brand Explained Residual Total
Sum
of squares
1727105.529 1727105.529 1727105.529 1413197.214 3140302.743
DF
4 4 4 135 139
and Dedcosystemswith all three systemssimilar to or better than glazed, followed by the Shofu and Den-Mat systems.
Statistics A one-way analysis of variance revealed a statistically significant difference between brands in both porcelain groups (TablesV and VI) whereastestsfor homogeneity of variances were positive for both porcelain groups. Least
Mean
square
431776.382 431776.382 431776.382 10468.128 22592.106
F
Significance
41.247 41.247 41.247
of F
0.000 0.000 0.000
significant difference (LSD) and Scheffe tests at the 0.050 level and Tukey tests disclosedthat for the Biobond porcelain, the Dedco and Dentsply systemswere similar and the Dentsply and Brasselersystemswere similar, followed by the Shofu systemin subsetthree and Den-Mat system in subset four (Table
II). For the Ceramco
porcelain,
the
Brasselerand Dentsply systemswere similar, the Dedeco and Shofu systems also resembled each other, ,and the Den-Mat system was in the third subset (Table III).
MAY
1991
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PORCELAIN
POLISHING
METHODS
8. SEM of Biobond porcelain finished with Den-Mat diamond porcelain polishing paste. (Original magnification X100.) Fig.
Table
VII. Surface
Combined evaluations rank ordered roughness
Ceramco porcelain 1 Brasseler 2 Dentsply 3 Dedeco 4 Shofu 5 Den-Mat Biobond porcelain 1 Dedeco 2 Dentsply 3 Brasseler 4 Shofu 5 Den-Mat
SEM
Prepolished surface roughnessanalysis (pm) Ceramco
Brand
Brasseler Dentsply Dedeco Shofu Den-Mat
Brasseler Dedeco Dentsply Shofu Den-Mat
Brasseler Dedeco Dentsply Shofu Den-Mat
Shofu Dentsply Brasseler Dedeco Den-Mat
Three separatemethods were used to evaluate the polishing of five commercially available products (Table VII). All testing wasperformed blind; the disks could be identified only by a number on the inferior surface known only by the investigator who did the polishing. Clinical evaluation correlated with the profilometer and SEM readings verified unanimously that the Brasselersystem wassuperior in polishing the Ceramcoporcelain and that the DenMat system was unacceptable for both porcelains. The investigators believedthat the lack of a rubber wheel to blend the surface irregularities causedby the high-speed diamond before use of the polishing compound compro-
OF PROSTHETIC
VIII.
Clinical
DISCUSSION
THE JOURNAL
Table
DENTISTRY
Dedeco Shofu Den-Mat Brasseler Dentsply Total
Mean
249.1429 202.8095 219.5714 235.2857 214.3333 224.2263
porcelain SD
74.5260 40.2723 58.6563 65.5165 79.5609 65.9638
Biobond Mean
262.9524 217.2381 266.2857 259.1429 245.3333 250.1905
porcelain SD
77.3905 57.6098 90.5727 68.2505 76.4332 75.5777
misedthe Den-Mat system. The Shofu systemwas highly rated clinically for the Biobond porcelain becauseof the resultant sheen. This finding was inconsistent with the SEM and profilometer readingswhere it ranked fourth. Becausethe Dedeco system developed a darkened surface on the Ceramcoporcelain that could not be removed in the ultrasonic bath, it wasdowngradedby the evaluators. Only the dental technician used digital pressureacross the porcelain surface to rank the surfaces. Although there wereslight differencesin the particle size of the filler materials, the pretest means (Table VIII) for the Biobond and the Ceramcoporcelainswere not statistically different.
CONCLUSIONS This experiment confirmed that the Brasseler,Dedeco, Dentsply, and Shofu porcelain polishing systems were
633
GOLDSTEIN,BARNHABD,ANDPENUGONDA
clinically acceptable for finishing ground porcelain. However, the Brasseler system was superior with Ceramco porcelain and the Den-Mat system was considered unacceptable.
Monasky GE, Taylor DF. Studies on the wear of porcelain, enamel, and gold. J PROSTHET DENT 1971;25:299-308. Sulik WD, Plekovitch EJ. Surface finishing of dental porcelain. J PROSTHET DENT
PROSTHET
We thank the statistics, the products
1. Podshadley A, Harrison JD. Rat connective tissue response to pontic materials. J PROSTHET DENT 196&l&110-8. 2. Henry PJ, Johnston JF, Mitchell DF. Tissue changes beneath fixed partial dentures. J PROSTHET DENT 1966;16:937-47. 3. Stein RS. Pontic residual ridge relationship: a research report. J PROS-
J. D. Brewer, D. A. Garlapo, State
University
analysis
D.D.S., M.S.,* D.D.S.*** of New
York
J. S. Glennon,
at Buffalo,
School
1980;43:258-65.
Reprint requests to: DR. GARY R. GOLDSTEIN KRWER DENTAL CENTER NEW YORK UNIVEFSITY 345 EAST 24TH ST. NEW YORK, NY 10010
1966$6:251-85.
Spectrophotometric porcelain
DENT
Zalkind M, Lauer S, Stern N. Porcelain surface texture after reduction and natural glazing. J PROSTHET DENT 1986;55:30-3. Klausner LH, Cartwright B, Charbeneau GT. Polishing versus autoglazed porcelain surfaces. J PROSTHET DENT 1982;47:157-62. Bessing C, Wiktorsson A. Comparison of two different methods of polishing porcelain. Stand J Dent Res 1983;91:482-‘7.
Dr. Gene Hittleman for his invaluable assistance with and the manufacturers listed in Table I for donating used in the study.
REFERENCES
THET DENT
1981;46:217-21.
Schlissel ER, Newitter DA, Renner RR, Gwinett AJ. An evaluation of postadjustment polishing techniques for porcelain denture teeth. J
of a nongreening, D.D.S.,**
of Dental
Medicine,
metal-fusing
and Buffalo,
N.Y.
Spectrometric analysis has been used previously to examine color differences among various porcelains and metal ceramic systems. This study determined whether nongreening porcelain of a single shade fused to high-gold and palladiumsilver alloys results in the same final color. Both conventional (VMK-68) and nongreening (VMK-68N) porcelains were fused to metal coupons of high gold (Will-Ceram Y) and palladium-silver (Will-Ceram W-l) to make up four groups. CIELAB calorimetric data were collected at each of seven fabrication steps to define color differences between steps for each alloy-porcelain group as well as between groups at each step. For the shade tested, perceptible color differences between high-gold/conventional porcelain and palladium-silverlnongreening porcelain coupons did not support manufacturers’ claims. (J PROSTHET DENT 1991;65:634-41.)
M
atching the color of dental materials and natural teeth is challenging and can be frustrating. The number and availability of esthetic restorative materials is expanding rapidly, and dentists must be familiar not only with the behaviorsof individual products but alsowith the effects of interactions between the materials. The acceptance of alternative ceramic alloys, for example, hasintro-
Presented at the Academy of Denture Prosthetics meeting, Corpus Christi, Texas. *Assistant Professor, Department of Fixed Prosthodontics. **Postdoctoral Student in Prosthodontics. ***Professor and Chairman, Department of Fixed Prosthodontics.
10/1/27236 634
duced inconsistenciesin the color of metal ceramic restorations produced with various alloy-porcelain systems. Brewer et al.’ examinedand quantified color differences for three alloys combined with a single porcelain. Color differenceswere found betweenthe palladium-silver based and high-gold basedsamples.Barghi and Richardson2had previously reported that final color wasnot influenced by various high-gold content alloys, The effects of other manipulative variables on the color of metal ceramic restorations has been examined by several investigators,3-6but most recently by Rosenthiel and Johnston.’ Current accepted instrumental calorimetry, which was usedin their investigation, had previously beenapplied by Seghi et ah8to define color differencesfound between different brands of porcelain of the samenominal shade in both opaqueand layered porcelain samples.Shaffner and MAY
1991
VOLUME
66
NUMBER
6
strength of the castable ceramic crown. This suggested that an internal escape channel was indicated for posterior Dicar castable ceramic crowns.
10. Tjan AHL, Sarkissian R. Internal escape channel: an alternative to venting complete crowns. J PROSTHET DENT 19&1;52:50-6. 11. Dicer Research Report. ~012. issue 1. February 1986. Dentsply International Inc., York, Pa. 12. Malament KA, Grossman DG. The cast glass-ceramic restoration. J PROSTIXEF DENT 1987;57:674-83.
REFERENCES 1. Phillips RW. Skinner’s science of dental materials. 8th ed. Philadelphia: WB Saunders Co, 1981:463-4,510-X 2. Eames WB, O’Neal SJ, Monteiro J, Miller C, Roan JD Jr, Cohen KS. Techniques to improve the seating of castings. J Am Dent Assoc 1978;96:432-7.
3. Cooper TM, Christensen GJ, Laswell HR, Baster R. Effect of venting on cast gold full crowns. J PROSTHET DENT 1971;26:621-6. 4. Meyers GE. DOSand don’ts for three dental luting cements. J Am Dent Assoc 1978;97:502-4. 5. Tjan AHL, Sarkissian R. Comparison of internal escape channels with die spacing and occlusal venting. J PROSTHET DENT 1985;53:613-7. 6. Tjan AHL, Sarkissian R, Miller GD. Internal escapechannel to improve the seating of full crowns with various marginal configurations: a follow-up study. J PROSTHJST DENT 1985;53:759-62. 7. Webb EL, Murray HV, Holland GA, Taylor DF. Effects of preparation relief and flow channels on seating full coverage castings during cementation. J PROSTHET DENT 1983;49:777-80. 8. Phillips RW. Skinner’s science of dental materials. 8th ed. Philadelphia: WB Saunders Co, 1981:404. 9. Phillips RW. Skinner’s science of dental materials. 8th ed. Philadelphia: WB Saunders Co, 1981:38.
Profilometer, SEM, and visual polishing methods Gary R. Goldstein, D.D.S.,* Bruce R. Barnhard, Bapanaiah Penugonda, D.D.S., M.S.*** New York University,
13. Miller GD, Tjan AHL. The internal escape channel; a solution to incomplete seating of full cast crowns. J Am Dent Assoc 1982;104: 322-4. 14. Rosenstiel SF, Gegauff AG. Improving the cementation of complete cast crowns: a comparison of static and dynamic seating methods. J Am Dent Assoc 1988;117:845-8. 15. Vermilyea SG, Kuffler MJ, Huget EF. The effects of die relief agent on the retention of full coverage castings. J PROSTHET DENT 1983;50:20710.
16. Burkl CE, Ocampo BS. Compressive strengths of a new foil and porcelain-fused-to-metal CIOWIIS. J PROSTHET DENT 1987;57:404-10. 17. Gibbs CH, Mahan PE, Lundeen HC, Brehnan K, Walsh EF, Holbrook WB. Occlusal forces during chewing and swallowing as measured by sound transmission. J PROSTHETDENT 1981;46:443-9. 18. Brukl CE, Philp GK. The fit of molded all-ceramic, twin foil, and conventional ceramic crowns. J PROSTHET DENT 1987;58:408-13. Reprint requests to: DR. KENNETH M. HARRISON 768 SOOTHLEAFDR. VIRGINIA BEACH, VA 23462
assessment
of porcelain
D.D.S.,** and
Kriser Dental Center, New York, N.Y.
Research has indicated that polishing ground porcelain is essential to control the wear of opposing occlusal surfaces and reduce the inflammation of contacted soft tissue. Five popular methods for polishing porcelain were evaluated by use of a profilometer, SEM, and normal vision. Seventy disks, 36 Biobond disks and 36 Ceramco disks, were roughened with a green stone and polished with one of the methods according to the manufacturers’ directions. Brasseler, Dedeco, Dentsply, and Shofu porcelain polishing systems were suitable for restoring ground porcelain. However, clinical evaluations correlated to the profilometer and SEM readings revealed that the Brasseler system was superior for polishing Ceramco porcelain whereas the Den-Mat system was unacceptable. (J PROSTEET DENT 1991;66$27-34.)
T
he use of porcelain as a restorative material has created numerous concerns for the clinician. Unglazed porcelain has been shown to cause unfavorable connective Presented at the Greater New York Academy of Prosthodontics meeting, New York, N.Y. *Professor, Department of Prosthodontics and Occlusion. **Consulting Medical StafF for Prosthodontics, Kessler Institute for Rehabilitation, New York, N.Y. ***Assistant Professor, Department of Comprehensive Care and Applied Practice Administration. 10/l/27941.
THEJOURNAL
OF PROSTHETIC DENTISTRY
tissue responsesl” and increase the potential for wear of opposing occlusal surfaces.4 Whereas the glazed surface is considered the ideal, the realities of the clinical environment dictate that minor alterations to the porcelain be corrected by polishing instead of reglazing. We conducted a survey of the faculty of the Department of Prosthodontics and Occlusion at New York University. Of the 53 responding clinicians, all except one polish minor adjustmenta to the porcelain surface rather than reglaze. The Shofu Porcelain adjustment kit (Shofu Dental Corp., Menlo Park, Calif.) was used by 3’7 members of the faculty,
GOLDSTEIN,
Fig.
Table
BARNHARD,
AND
PENUGONDA
1. SEM of glazed Ceramcoporcelain. (Original magnification X100.)
I. Products used in study
Table
II.
Surface roughnessanalysis of biobond
porcelain Product
Biobondporcelain Ceramcoporcelain DedecoSuperPolish rubberwheels ShofuPorcelain adjustmentkit Den-Mat Diamond/ Porcelainpolishingpaste Brasseler Truluster polishingsystem DentsplyPorcelain finishingkit
DentsplyInternational York, Pa. J & J Dental ProductsCo. EastWindsor,N.J. DedecoInternationalInc. LongEddy, N.Y. ShofuDentalCorp. Menlo Park, Calif. Den-Mat Corp. SantaMaria, Calif BrasselerUSA, Inc. Savannah,Ga. DentsplyInternational
with the remaining 16 divided among numerous other manufacturers. All but four of the responders used the samesystem for porcelain denture teeth. An SEM evaluation of a specific technique for repolishing an adjusted porcelain surface concluded that it appeared similar to the glazed surface.5Schlisselet al.‘j compared 11 techniques for adjusting porcelain denture teeth visually and by scanning electron microscope @EM) to discover that three approacheswere acceptable.An examination of the surface texture of porcelain with SEM after reduction and natural glazing confirmed that prepolishing wasnecessarybefore reglazing.’ Klausner et aLscompared
628
Mean
SD
1
Dedeco Dentsply Brasseler Shofu Den-Mat Brackets enclose Tukey tests.
Ra (pm)
Casts
205.6071 247.3214 264.1071
92.0778 95.0411 85.4866
28 28 28
382.0000]
61.6856
454.60711
84.3513
28 28
statistically
similar
groups
ee determined
by Scheffe
and
four techniques with both SEM and surface analyzer for porcelain polishing versusglazed porcelain without detecting a difference. Bessingand Wiktorssong compared two different porcelain polishing systems by both SEM and profilometer. They reported that the average roughness value (Ras) for the polished surfaceswaslessthan the Ras for the autoglazedsurfaces,but the SEM evaluations demonstrated the opposite result. This study compared the efficacy of five current porcelain polishingprocedureson two different dental porcelains visually, quantitatively with a profilometer, and qualitatively with an SEM.
MATERIAL
AND
METHODS
Thirty-five quarter-sized disks of Biobond (Dentaply International, York, Pa.) and Ceramco (J and J Dental Products, East Windsor, N.J.) porcelain were baked to a medium glaze by the respective manufacturer. One half of
MAY
1991
VOLUME
66
NUMBER
5
PORCELAIN
POLISHING
METHODS
Fig. 2. SEM of Ceramco porcelain finished with Brasseler Truluster (Original magnification X100.)
Table
III.
Surface roughness analysis of Ceramco
Table
porcelain Product
Brasseler Dentsply Dedeco Shofu Den-Mat
Porcelain Mean
Ra (pm)
1
181.9643 222.0714 307.6249 345.5000 500.53577
Brackets enclose statistically Tukey tests.
similar
1
SD 97.4905 111.0619 100.9265 76.6466 120.1692
groups as determined
Casts
28 28 28 28 28 by Sheffe and
each disk was abraded with a No. 120 green stone (Dedeco International Inc., Long Eddy, N.Y.) to simulate a clinical adjustment. The samples, seven per group, were then polished with the products listed in Table I, according to the manufacturers’ recommendations. After they were polished, the samples were cleaned for 10 minutes in a cleaning solution (Healthco International, Boston, Mass.) in an ultrasonic bath (T-14, L & R Mfg. Co., Kearny, N. J.). Surface roughness was recorded at four representative sites on each disk with a Mitutoyo Surftest(Mitutoyo Mfg. Co. Ltd., Tokyo, Japan) profilometer with a cutoff of 0.25 mm and a transverse length of 1.5 mm. Visual evaluations were performed by prosthodontists or dental technicians and the scanning electron micrographs (IS1 Super III A, International Scientific Instruments, Inc., Santa Clara, Calif.) were analyzed.
THE
JOURNAL
IV.
OF PROSTHETIC
DENTISTRY
polishing system.
Clinical evaluations and system
Biobond porcelain (Ranked by 8 evaluators) Shofu Dentsply Brasseler Dedeco Den-Mat*
Ceramco porcelain (Ranked by 7 evaluators) Brasseler Dedecot Dentsply Shofu Den-Mat*
Rank
order
First
place
21 21 19 9 0
4 2 2
35 18 8 1 0
7
votes
*Only Den-Mat was considered clinically unacceptable. tDedeco had a “dirty” looking darkened surface after polishing that could not be removed in ultrasonic bath, all clinicians tended to downgrade it as a result.
The tests performed by the evaluators were designed as a blind study. RESULTS The means of the profilometer tests were presented in Tables II and III. Clinical evaluations are displayed in Table IV, with the polished disks ranked from smoothest to
GOLDSTEIN,
BARNHARD,
AND
PENUGONDA
Fig. 3. SEM of Ceramco porcelain finished with Densply porcelain polishing kit. (Original magnification X100.)
Fig. 4. SEM of Ceramco porcelain finished with Shofu porcelain polishing kit. (Original magnification X100.)
roughest. The evaluators judged shine and smoothness and were also asked tc note any clinically unacceptable samplea. Five points were assigned for first place, three points for second place, one point for third place, and no point for fourth and fifth place. Eight clinical evaluators judged the 630
Shofu system best for Biobond porcelain with 21 points and four first place votes; the Dentaply system ranked next with 21 points and two first place votes, and the Brasseler systern collected 19 points and two first place votes, the Dedeco system received nine points and the Den-Mat system MAY
1901
VOLUME
65
NUMBER
5
PORCELAIN
POLISHING
METHODS
Fig. 5. SEM of glazed Biobond porcelain. (Original magnification
Fig. 6. SEM of Biobond porcelain finished with Brasseler Truluster (Original magnification X100.)
was last without points. For the Ceramco porcelain, seven clinical evaluators rated the Brasseler system superior with 35 points and all seven evaluators awarding a first place vote, the Dedco system with 18 points, the Dentsply system with eight points, and the Shofu systems with one point. THE
JOURNAL
OF PROSTHETIC
DENTISTRY
X100.)
polishing system.
The SEMs (Figs. 1 through 8) were evaluated and ranked as follows: for the Biobond porcelain, the Brasseler systern was considered equal to or better than glazed, followed by the Dedeco, Dentsply, Shofu, and Den-Mat systems. The Ceramco porcelain was ranked: Brasseler, Dentsply, 631
GOLDSTEIN,
BARNHARD,
AND
PENVGONDA
Fig. 7. SEM of Biobond porcelain finished with Dentsply porcelain polishing kit. (Original magnification X100.)
Table
V. Source
Analysis of variance for Biobond porcelain of variation
Main effects Brand Explained Residual Total
Table
VI. Source
Sum
of squares
1204705.543 1204705.543 1204705.543 964962.143 2169667.686
DF
4 4 4 135 139
Mean
square
301176.386 301176.386 301176.386 7147.868 15609.120
F
Significance
42.135 42.135 42.135
of F
0.000 0.000 0.000
Analysis of variance for Ceramco porcelain of variation
Main effects Brand Explained Residual Total
Sum
of squares
1727105.529 1727105.529 1727105.529 1413197.214 3140302.743
DF
4 4 4 135 139
and Dedcosystemswith all three systemssimilar to or better than glazed, followed by the Shofu and Den-Mat systems.
Statistics A one-way analysis of variance revealed a statistically significant difference between brands in both porcelain groups (TablesV and VI) whereastestsfor homogeneity of variances were positive for both porcelain groups. Least
Mean
square
431776.382 431776.382 431776.382 10468.128 22592.106
F
Significance
41.247 41.247 41.247
of F
0.000 0.000 0.000
significant difference (LSD) and Scheffe tests at the 0.050 level and Tukey tests disclosedthat for the Biobond porcelain, the Dedco and Dentsply systemswere similar and the Dentsply and Brasselersystemswere similar, followed by the Shofu systemin subsetthree and Den-Mat system in subset four (Table
II). For the Ceramco
porcelain,
the
Brasselerand Dentsply systemswere similar, the Dedeco and Shofu systems also resembled each other, ,and the Den-Mat system was in the third subset (Table III).
MAY
1991
VOLUME
65
NUMBER
5
PORCELAIN
POLISHING
METHODS
8. SEM of Biobond porcelain finished with Den-Mat diamond porcelain polishing paste. (Original magnification X100.) Fig.
Table
VII. Surface
Combined evaluations rank ordered roughness
Ceramco porcelain 1 Brasseler 2 Dentsply 3 Dedeco 4 Shofu 5 Den-Mat Biobond porcelain 1 Dedeco 2 Dentsply 3 Brasseler 4 Shofu 5 Den-Mat
SEM
Prepolished surface roughnessanalysis (pm) Ceramco
Brand
Brasseler Dentsply Dedeco Shofu Den-Mat
Brasseler Dedeco Dentsply Shofu Den-Mat
Brasseler Dedeco Dentsply Shofu Den-Mat
Shofu Dentsply Brasseler Dedeco Den-Mat
Three separatemethods were used to evaluate the polishing of five commercially available products (Table VII). All testing wasperformed blind; the disks could be identified only by a number on the inferior surface known only by the investigator who did the polishing. Clinical evaluation correlated with the profilometer and SEM readings verified unanimously that the Brasselersystem wassuperior in polishing the Ceramcoporcelain and that the DenMat system was unacceptable for both porcelains. The investigators believedthat the lack of a rubber wheel to blend the surface irregularities causedby the high-speed diamond before use of the polishing compound compro-
OF PROSTHETIC
VIII.
Clinical
DISCUSSION
THE JOURNAL
Table
DENTISTRY
Dedeco Shofu Den-Mat Brasseler Dentsply Total
Mean
249.1429 202.8095 219.5714 235.2857 214.3333 224.2263
porcelain SD
74.5260 40.2723 58.6563 65.5165 79.5609 65.9638
Biobond Mean
262.9524 217.2381 266.2857 259.1429 245.3333 250.1905
porcelain SD
77.3905 57.6098 90.5727 68.2505 76.4332 75.5777
misedthe Den-Mat system. The Shofu systemwas highly rated clinically for the Biobond porcelain becauseof the resultant sheen. This finding was inconsistent with the SEM and profilometer readingswhere it ranked fourth. Becausethe Dedeco system developed a darkened surface on the Ceramcoporcelain that could not be removed in the ultrasonic bath, it wasdowngradedby the evaluators. Only the dental technician used digital pressureacross the porcelain surface to rank the surfaces. Although there wereslight differencesin the particle size of the filler materials, the pretest means (Table VIII) for the Biobond and the Ceramcoporcelainswere not statistically different.
CONCLUSIONS This experiment confirmed that the Brasseler,Dedeco, Dentsply, and Shofu porcelain polishing systems were
633
GOLDSTEIN,BARNHABD,ANDPENUGONDA
clinically acceptable for finishing ground porcelain. However, the Brasseler system was superior with Ceramco porcelain and the Den-Mat system was considered unacceptable.
Monasky GE, Taylor DF. Studies on the wear of porcelain, enamel, and gold. J PROSTHET DENT 1971;25:299-308. Sulik WD, Plekovitch EJ. Surface finishing of dental porcelain. J PROSTHET DENT
PROSTHET
We thank the statistics, the products
1. Podshadley A, Harrison JD. Rat connective tissue response to pontic materials. J PROSTHET DENT 196&l&110-8. 2. Henry PJ, Johnston JF, Mitchell DF. Tissue changes beneath fixed partial dentures. J PROSTHET DENT 1966;16:937-47. 3. Stein RS. Pontic residual ridge relationship: a research report. J PROS-
J. D. Brewer, D. A. Garlapo, State
University
analysis
D.D.S., M.S.,* D.D.S.*** of New
York
J. S. Glennon,
at Buffalo,
School
1980;43:258-65.
Reprint requests to: DR. GARY R. GOLDSTEIN KRWER DENTAL CENTER NEW YORK UNIVEFSITY 345 EAST 24TH ST. NEW YORK, NY 10010
1966$6:251-85.
Spectrophotometric porcelain
DENT
Zalkind M, Lauer S, Stern N. Porcelain surface texture after reduction and natural glazing. J PROSTHET DENT 1986;55:30-3. Klausner LH, Cartwright B, Charbeneau GT. Polishing versus autoglazed porcelain surfaces. J PROSTHET DENT 1982;47:157-62. Bessing C, Wiktorsson A. Comparison of two different methods of polishing porcelain. Stand J Dent Res 1983;91:482-‘7.
Dr. Gene Hittleman for his invaluable assistance with and the manufacturers listed in Table I for donating used in the study.
REFERENCES
THET DENT
1981;46:217-21.
Schlissel ER, Newitter DA, Renner RR, Gwinett AJ. An evaluation of postadjustment polishing techniques for porcelain denture teeth. J
of a nongreening, D.D.S.,**
of Dental
Medicine,
metal-fusing
and Buffalo,
N.Y.
Spectrometric analysis has been used previously to examine color differences among various porcelains and metal ceramic systems. This study determined whether nongreening porcelain of a single shade fused to high-gold and palladiumsilver alloys results in the same final color. Both conventional (VMK-68) and nongreening (VMK-68N) porcelains were fused to metal coupons of high gold (Will-Ceram Y) and palladium-silver (Will-Ceram W-l) to make up four groups. CIELAB calorimetric data were collected at each of seven fabrication steps to define color differences between steps for each alloy-porcelain group as well as between groups at each step. For the shade tested, perceptible color differences between high-gold/conventional porcelain and palladium-silverlnongreening porcelain coupons did not support manufacturers’ claims. (J PROSTHET DENT 1991;65:634-41.)
M
atching the color of dental materials and natural teeth is challenging and can be frustrating. The number and availability of esthetic restorative materials is expanding rapidly, and dentists must be familiar not only with the behaviorsof individual products but alsowith the effects of interactions between the materials. The acceptance of alternative ceramic alloys, for example, hasintro-
Presented at the Academy of Denture Prosthetics meeting, Corpus Christi, Texas. *Assistant Professor, Department of Fixed Prosthodontics. **Postdoctoral Student in Prosthodontics. ***Professor and Chairman, Department of Fixed Prosthodontics.
10/1/27236 634
duced inconsistenciesin the color of metal ceramic restorations produced with various alloy-porcelain systems. Brewer et al.’ examinedand quantified color differences for three alloys combined with a single porcelain. Color differenceswere found betweenthe palladium-silver based and high-gold basedsamples.Barghi and Richardson2had previously reported that final color wasnot influenced by various high-gold content alloys, The effects of other manipulative variables on the color of metal ceramic restorations has been examined by several investigators,3-6but most recently by Rosenthiel and Johnston.’ Current accepted instrumental calorimetry, which was usedin their investigation, had previously beenapplied by Seghi et ah8to define color differencesfound between different brands of porcelain of the samenominal shade in both opaqueand layered porcelain samples.Shaffner and MAY
1991
VOLUME
66
NUMBER
6
