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Pulp response to Enamelite restorations in teeth of rhesus monkeys
Pulp rhesus
response
to Enam&e
reatardiatis
in teeth
of
monkeys
Edward M. Amet, D.D.S., University of Missouri-Kansas
M.S.,* and Fayez S. Sayegh, D.D.S., Ph.D.** City, School of Dentistry, Kansas City, MO.
I
n the last few years, much attention has been focused on developing a new anterior restorative material with properties superior to those of the previously used silicate cement and acrylic resin.* The problem has been one of developing a material that is esthetically pleasing, easy to manipulate, and nontoxic to the pulp.* Historically, anterior teeth with carious lesions have been treated with silicate cement or acrylic resin3, 4 In an attempt to develop a better material, recent research has been directed toward testing composite resins both in vitro and in vivo.5y fi These types of tests were done to find a material with more ideal properties. The purpose of this study was to evaluate the pulp response to Enamelite,? a composite resin. Histologic evaluation of the acute and chronic pulp responses was done according to Stanley7! * with modifications as detailed by Sayegh and Reed.g METHOD Three 8 to 15 pound adult rhesus (Macaca mulatta) monkeys provided 20 teeth each for the experiment. Two animals were used for the 1 week acute phase, and the third was used for the 6 week chronic phase. Deep Class V facial cavity preparations were made on anterior and premolar teeth. An attempt was made to reduce the dentin to 1 mm. or less by removing enamel and dentin until a slight pink color became evident. In each of the three animals, 10 teeth were restored with Enamelite after etching the enamel. Ten contralateral teeth in each animal were restored with zinc oxide/eugenol (ZOE) cement after etchant had been applied. The etchant, a tinted jelly-like substance of 50 per cent phosphoric acid, was applied with a cotton pellet to the enamel only for 2 minutes. The acid was removed with water. The cavities were prepared with air-driven angle handpieces with No. 35 carbide From a thesis submitted by Dr. Amet in partial fulfillment degree Master of Science at the University of Missouri at Kansas *Private practice, Kansas **Professor and Chairman, +Lee
42
Pharmaceuticals,
City, MO. Histology
South
El Monte,
Department. Calif.
of the City.
requirements
for
the
Volume Number
37 1
Pulp
response
to Enamelite
restorations
43
Fig. 1. A photomicrograph of a histologic section of a ZOE (1 week) specimen showing no reparative dentin formation. A slight cellular displacement and superficial response can be seen. T, dentinal tubules; 0, odontoblastic layer; and P, pulp. (Original magnification ~1,000.)
Table
I. Summary
of results for specimens ZOE Catepories
Number of teeth Average R.D. thickness (mm.) Average degree of cellular displacement (O-3) Average degree of superficial response (O-3) Average degree of deep response (O-3) Presence or absence of reparative dentin (+ or -) Presence or absence of hemorrhage (+ or -)
Enamelite
I week
6 weeks
I week
6 weeks
20 0.71 0.86 0.82 0.09 +
10 0.71 0.02 0.60 0.00 + +
15 0.61 1.40 I.20 0.27 +
8 0.80 0.00 0.62 0.00 + +
burs under an air/water coolant. Drying was accomplished with cotton pellets. No bases or liners were used to insulate or seal the cut dentin prior to insertion of the Enamelite. All teeth with clinical exposures were eliminated from the study. The teeth were extracted to provide 4-0, 1 week and 20, 6 week specimens, and these were processed by routine histologic methods. All of the sections of each tooth were studied to find those that had the least remaining dentin between the axial wall and the odontoblastic layer. Measurements of the remaining dentin were determined by use of a calibrated ocular grid attached to a microscope. RESULTS The
The results for both materials, ZOE and Enamelite, value for the remaining dentin (R.D.) thickness
are summarized in Table I. varied from 0.2 to 1.0 mm.
44
Amet and Sayegh
.I. Prosthet. January.
Dent. 197:
Fig. 2. A photomicrograph of a histologic section of an Enamelite (1 week) specimen showing no reparative dentin formation. A superficial and deep response can be seen as well as the cellular displacement. T, dentinal tubules; 0, odontoblastic layer; and P, pulp. (Original magnification x1,000.)
Only those teeth with a remaining dentin of 1.0 mm. or less were included in this study. ZOE and Enamelite (I week). Twenty teeth were considered acceptable out of 20 treated with ZOE, having an average R.D. of 0.71 mm. The Enamelite group had 15 acceptable teeth out of 20, with an average R.D. of 0.61 mm. The R.D. thicknesses for both materials were comparable. The cellular displacement, superficial responses, and deep responses were less for specimens restored with ZOE than for the Enamelite specimens at the 1 week postoperative period. Fig. 1 is representative for the ZOE during this time period, as Fig. 2 is for the Enamelite. Teeth restored with Enamelite in the 1 week postoperative group contributed the only specimens that showed substantial inflammatory responses. In this group of 15 teeth, three abscesses were found when the remaining dentin was 0.3 mm. or less (Fig. 3). The average cellular displacement was 0.86 for the ZOE group and 1.40 for the Enamelite group, indicating a greater pulpal response to the Enamelite. The superficial response for the ZOE was 0.82, while the response for Enamelite at the same time interval was 1.20, again showing a greater pulpal response to the Enamelite. The average degree of deep response was 0.09 for the ZOE and 0.27 for the Enamelite. No reparative dentin formed for either material at 1 week. Hemorrhage was comparable for both materials. ZOE and Enamelite (6 weeks). Ten teeth were considered acceptable out of 10 trea.ted with ZOE, having an R.D. of 0.71 mm. The Enamelite group had eight teeth that were considered acceptable out of 10 treated, with an average R.D. of 0.80 mm. The R.D. thicknesses of both materials at this time interval again were comparable. Fig. 4 is representative of the ZOE during this time period, as is Fig. 5 for Enamelite. The average degree of cellular displacement was 0.02 for the ZOE and 0.0 for
Volume Number
37 1
3. A photomicrograph of a histologic ess formation. C, cavity preparation; catic m x250.) Fig.
Fig. tive
Pulp
section
response
to Enamelite
of an Enamelite (1 week) dentin; and P, pulp.
R, remaining
restorations
specimen (Original
45
showing magnifi-
4. A photomicrograph of a histologic section of a ZOE (6 week) specimen showin g reparaand a lack of a deep inflammatory response. A slight superficial r( 5sponse is de mtin formed en1t. R, reparative dentin; P, pulp; and D, primary dentin. (Original magnificatic m x250.)
46
Amet and SaysgIl
Fig. 5. A photomicrograph a very mild superficial is present. D, primary x250.)
of a histologic section of an Enamelite (6 week) specimen showing response and lack of a deep response. Well formed secondary dentin dentin; R, reparative dentin; and P, pulp. (Original magnification
the Enamelite. The average degrees of superficial response were comparable, with 0.60 for the ZOE and 0.62 for the Enamelite. None of the ZOE specimens showed deep inflammatory responses at the 6 week postoperative period (Fig. 4). This was also true for the .6 week postoperative Enamelite specimens (Fig. 6). Reparative dentin formation was good for both materials at the 6 week period (Figs. 4 and 6). Hemorrhage was comparable for both materials. DISCUSSION When the literature related to the biologic effects of restorative materials is critically reviewed, the great variability among the findings of investigators is SO noticeable that it is not surprising that diverse conclusions have been reached. HOWever, the essential points of these experiments should not be overlooked when interpreting the validity of the conclusions. Different experimental methods are a partial cause of this diversity, and they make it difficult to compare results of various investigators and to decide whether any particular work has been adequately confirmed. The remaining dentin thickness is considered to be a crucial factor when investigating pulp response.“. (i According to Stanley,7, s 2 mm. of dentin thickness will provide an adequate insulating barrier against toxic elements. Langeland and Langelandlo found that a thick layer of dentin does not necessarily protect the pulp, and severe reactions may occur even if cavities are shallow. In their study of composite materials, Langeland and associates” found moderate and severe pathologic reactions in spite of thicknesses of up to 2.1 mm. However, Sayegh and Reed”. I1 have shown that the remaining dentin in rhesus monkeys should be less than that in human beings if the results of these two types of studies are to be correlated. Thus, in the present
Pulp response to Enamelzte restorations
47
Fig. 6. A photomicrograph of a histologic section of an Enamelite (6 week) specimen showing a lack of a deep inflammatory response. Well formed secondary dentin is present. P, puIp; 0, odontoblastic layer; R, reparative dentin; and D, primary dentin. (Original magnification x1,000.)
study, the recommendations of Stanley’, 8 were modified so that only sections of remaining dentin of 1 mm. or less were used in all categories. The remaining dentin thicknesses of all teeth in this study ranged from 0.20 to 1.35 mm. Those teeth with histologic exposure, as determined during the initial microscopic screening, were considered unacceptable. Also teeth with a remaining dentin thicker than 1.0 mm. were similarly eliminated from the study. The remaining dentin was calculated from measurements obtained from all the sections made of each tooth, with the number of sections in some teeth reaching 85. The Enamelite produced three abscesses in the I week period when the remainthat are ing dentin was 0.3 mm. or less. Th is indicates the presence of ingredients toxic to the pulp if there is little remaining dentin to protect the pulp tissue or if the material is placed directly over an exposure. The degree of the inflammatory response in this investigation for the 6 week Enamelite group was milder than that reported with other composite resins.“, ‘. ” The fact that no significant reactions were observed in this group does not mean that composite resins should be used without a liner, as recommended for Addent 3513, 14; they should be used with a liner. The possibility of an undetected pulp exposure when preparing a deep cavity must not be overlooked.” This situation could account for the three abscesses in the 1 week specimens. Therefore, it is recommended that every deep cavity preparation be treated as a potential pulp exposure by placing a protective barrier that will seal the .involved dentinal tubules. This agrees with the recommendation of StanleyI” that until other liners have been studied more extensively, a calcium hydroxide liner is the best protection under composite restorations.
48
Amet
and Sayegh
.J. 1’1oathct. Dent. January, 1917
Finally, poor adaptation represents a serious threat to the pulp, causing more irritation than the actual material. I2 So far as microleakage is concerned, most composite resins are not superior to the conventional resins.17 However, it has been shown that simple acid etching of enamel can increase the adhesion of the acrylic resin filling material and decrease the microleakage.l* The physical properties of the Enamelite material are such that it can easily flow into cavity preparations and take advantage of acid-etched enamel for bonding, as was done in this study to decrease microleakage and resultant pulpal injury. SUMMARY
AND
CONCLUSIONS
The average magnitudes of cellular displacements, superficial responses, and deep responses were less for specimens restored with ZOE than for Enamelite specimens at the 1 week postoperative period, Of 20 teeth treated, three abscesses were found in the 1 week Enamelite postoperative period when the remaining dentin was 0.3 mm, or less. This indicates the presence of ingredients that are toxic to the pulp when there is little remaining dentin or when the material is placed directly over an exposure. Teeth restored with Enamelite in the 6 week group had values comparable to the ZOE teeth for the same time period. References 1. Chang, R. W. H., Dahlman, K. E., and Ruth, J. T.: Properties of Glass-Reinforced Polymeric Material for Dental Filling, Int. Assoc. Dent. Res. Abst. No. 182, July, 1965. 2. Langeland, I,. K., Guttuso, J., Jerome, D. R., and Langeland, K.: Histologic and Clinical Comparison of Addent With Silicate Cements and Cold Curing Materials, J. Am. Dent. ASSOC. 72: m-m, 1966. 3. Fillerbrown, F. G. : Plastic Fillings, Dent. Items Int. 12: 312, 1890. 4. Shroff, F. R.: Effects of Filling Materials on the Dental Pulp. A Critical Review, J. Dent. Educ. 16: 246-259, 1952. 5. MrCurdy, C. R., Swartz, M. I,.. Phillips, R. W., and Rhodes, B. F.: A Comparison of 111 Vivo and in Vitro Microleakage of Dental Restorations, J. Am. Dent. Assoc. 88: 592-60’2, 1974. 6. Stanley, lI. R., Swerdlow, li., and Buonocore, M. G.: Pulp Reactions to .4nterior Re$torative Materials, J. Am. Dent. .4ssoc. 75: 132-141, 1967. 7. Stanley, H. R.: Design for a Human Pulp Study. Part I, Oral Surg. 25: 633-647, 1968a. 8. Stanley, H. R.: Design for a Human Pulp Study. Part II, Oral Surg. 25: 756-764, 1968b. 9. Sayegh, F. S., and Reed, A. J.: Analysis of Histologic Criteria Commonly Used in Pulp Studies, Oral Surg. 37: 457-462, 1974. 10. Langeland, K., and Langeland, 1~. K.: Pulp Reactions to Crown Preparation, Impression, Temporary Crown Fixation and Permanent Cementation, J. PROSTHET. DENT. 15: I29143, 1965. 11. Sayegh, F. S., and Reed, A. J.: Critique and Comparison of Pulp Responses in Monkey and Human Teeth, Int. Assoc. Dent. Res. Abst. No. 525, March, 1970. Pulpal Reaction to Composite Resin Restorations, J. 12. Brsnnsttim, M., and Nyhorg, H.: PROSTHET. DENT. 27: 181-189, 1972. 13. Russell, J. R., Grove, D. M., and Cotton, W. R.: Pulp Response in Rat Molars to a New Restorative Material, Oral Surg. 24: 253-262, 1967. of the Human Pulp to a New Restorative 14. Baume, I.. J., and Fiore-Donno, G.: Response Material, J. Am. Dent. Assoc. 76: 1016-1022, 1968. 15. Hassan, E. H., Van Huysen, G., and Gilmore, H. W.: Deep Cavity Preparation and the Tooth Pulp, J. PROSTHET. DENT. 16: 751-755, 1966.
$3hm&
;1
”
16. 17. 18.
Pulp
response
to Enamelite
restorations
49
Stanley, H. R.: Pulpal Response to Dental Techniques and Materials, Dent. Clin. North Am. 15: 115-126, 1971. Phillips, R. W.: Report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry, J. PROSTHET. DENT. 23: 665-690, 1970. Buonocore, M. G., Matsui, A., and Gwinnett, A. J.: Penetration of Resin Dental Materials Into Enamel Surfaces With Reference to Bonding, Arch. Oral Biol. 13: 61-70, 1968. DR. AMET 911 MAIN ST. COMMERCE TOWER KANSAS CITY, MO.
BLDG. 64105
DR. SAYECH UNIVERSITY OF MISSOURI-KANSAS SCHOOL OF DENTISTRY KANSAS CITY, MO. 64108
ARTICLES
CITY
TO APPEAR IN FUTURE
A new semiadjustable articulator. capability of the Hanau XP-51 Israel
M.
Finger,
B.D.S.,
M.Sc.,
Acid-etch/composite Anna
B. Fuks,
Vinyl
chloride
Oscar
N. Guerra,
Edward
A temporary resin David
Kochavi,
Outline Keki
M.S.P.H.,
Shapira,
space D.M.D.,
B.D.S.,
P. Lubovich,
Tanaka,
D.D.S.,
of fractured
of the
M.Sc.
anterior
teeth
D.M.D.
in maxillofacial
D.D.S.,
of canine Kahn,
Bond strength ceramic-metal Ronald
and Joseph
of standards
R. Kotwal,
and Hisatoshi
concentrations
The importance Arthur
Part III. An investigation articulator
resin restoration
C.D.,
ISSUES
prosthetics
and Kenneth
and anterior
laboratories
J. Kronoveter,
tooth
M.S.
positions
in occlusion
D.D.S.
maintainer Noah
using
Stern,
D.M.D.,
for evaluating D.M.D.,
acrylic
M.S.,
patients
resin
M.S.D.,
and
MS.,
and
and
Rafael
a composite
Grajower,
for overdentures
F.A.C.P.
studies of precious, semiprecious, alloys with two porcelains D.D.S.,
teeth
Richard
J. Goodkind,
and
nonprecious D.M.D.,
M.S.
Ph.D.
response
to Enam&e
reatardiatis
in teeth
of
monkeys
Edward M. Amet, D.D.S., University of Missouri-Kansas
M.S.,* and Fayez S. Sayegh, D.D.S., Ph.D.** City, School of Dentistry, Kansas City, MO.
I
n the last few years, much attention has been focused on developing a new anterior restorative material with properties superior to those of the previously used silicate cement and acrylic resin.* The problem has been one of developing a material that is esthetically pleasing, easy to manipulate, and nontoxic to the pulp.* Historically, anterior teeth with carious lesions have been treated with silicate cement or acrylic resin3, 4 In an attempt to develop a better material, recent research has been directed toward testing composite resins both in vitro and in vivo.5y fi These types of tests were done to find a material with more ideal properties. The purpose of this study was to evaluate the pulp response to Enamelite,? a composite resin. Histologic evaluation of the acute and chronic pulp responses was done according to Stanley7! * with modifications as detailed by Sayegh and Reed.g METHOD Three 8 to 15 pound adult rhesus (Macaca mulatta) monkeys provided 20 teeth each for the experiment. Two animals were used for the 1 week acute phase, and the third was used for the 6 week chronic phase. Deep Class V facial cavity preparations were made on anterior and premolar teeth. An attempt was made to reduce the dentin to 1 mm. or less by removing enamel and dentin until a slight pink color became evident. In each of the three animals, 10 teeth were restored with Enamelite after etching the enamel. Ten contralateral teeth in each animal were restored with zinc oxide/eugenol (ZOE) cement after etchant had been applied. The etchant, a tinted jelly-like substance of 50 per cent phosphoric acid, was applied with a cotton pellet to the enamel only for 2 minutes. The acid was removed with water. The cavities were prepared with air-driven angle handpieces with No. 35 carbide From a thesis submitted by Dr. Amet in partial fulfillment degree Master of Science at the University of Missouri at Kansas *Private practice, Kansas **Professor and Chairman, +Lee
42
Pharmaceuticals,
City, MO. Histology
South
El Monte,
Department. Calif.
of the City.
requirements
for
the
Volume Number
37 1
Pulp
response
to Enamelite
restorations
43
Fig. 1. A photomicrograph of a histologic section of a ZOE (1 week) specimen showing no reparative dentin formation. A slight cellular displacement and superficial response can be seen. T, dentinal tubules; 0, odontoblastic layer; and P, pulp. (Original magnification ~1,000.)
Table
I. Summary
of results for specimens ZOE Catepories
Number of teeth Average R.D. thickness (mm.) Average degree of cellular displacement (O-3) Average degree of superficial response (O-3) Average degree of deep response (O-3) Presence or absence of reparative dentin (+ or -) Presence or absence of hemorrhage (+ or -)
Enamelite
I week
6 weeks
I week
6 weeks
20 0.71 0.86 0.82 0.09 +
10 0.71 0.02 0.60 0.00 + +
15 0.61 1.40 I.20 0.27 +
8 0.80 0.00 0.62 0.00 + +
burs under an air/water coolant. Drying was accomplished with cotton pellets. No bases or liners were used to insulate or seal the cut dentin prior to insertion of the Enamelite. All teeth with clinical exposures were eliminated from the study. The teeth were extracted to provide 4-0, 1 week and 20, 6 week specimens, and these were processed by routine histologic methods. All of the sections of each tooth were studied to find those that had the least remaining dentin between the axial wall and the odontoblastic layer. Measurements of the remaining dentin were determined by use of a calibrated ocular grid attached to a microscope. RESULTS The
The results for both materials, ZOE and Enamelite, value for the remaining dentin (R.D.) thickness
are summarized in Table I. varied from 0.2 to 1.0 mm.
44
Amet and Sayegh
.I. Prosthet. January.
Dent. 197:
Fig. 2. A photomicrograph of a histologic section of an Enamelite (1 week) specimen showing no reparative dentin formation. A superficial and deep response can be seen as well as the cellular displacement. T, dentinal tubules; 0, odontoblastic layer; and P, pulp. (Original magnification x1,000.)
Only those teeth with a remaining dentin of 1.0 mm. or less were included in this study. ZOE and Enamelite (I week). Twenty teeth were considered acceptable out of 20 treated with ZOE, having an average R.D. of 0.71 mm. The Enamelite group had 15 acceptable teeth out of 20, with an average R.D. of 0.61 mm. The R.D. thicknesses for both materials were comparable. The cellular displacement, superficial responses, and deep responses were less for specimens restored with ZOE than for the Enamelite specimens at the 1 week postoperative period. Fig. 1 is representative for the ZOE during this time period, as Fig. 2 is for the Enamelite. Teeth restored with Enamelite in the 1 week postoperative group contributed the only specimens that showed substantial inflammatory responses. In this group of 15 teeth, three abscesses were found when the remaining dentin was 0.3 mm. or less (Fig. 3). The average cellular displacement was 0.86 for the ZOE group and 1.40 for the Enamelite group, indicating a greater pulpal response to the Enamelite. The superficial response for the ZOE was 0.82, while the response for Enamelite at the same time interval was 1.20, again showing a greater pulpal response to the Enamelite. The average degree of deep response was 0.09 for the ZOE and 0.27 for the Enamelite. No reparative dentin formed for either material at 1 week. Hemorrhage was comparable for both materials. ZOE and Enamelite (6 weeks). Ten teeth were considered acceptable out of 10 trea.ted with ZOE, having an R.D. of 0.71 mm. The Enamelite group had eight teeth that were considered acceptable out of 10 treated, with an average R.D. of 0.80 mm. The R.D. thicknesses of both materials at this time interval again were comparable. Fig. 4 is representative of the ZOE during this time period, as is Fig. 5 for Enamelite. The average degree of cellular displacement was 0.02 for the ZOE and 0.0 for
Volume Number
37 1
3. A photomicrograph of a histologic ess formation. C, cavity preparation; catic m x250.) Fig.
Fig. tive
Pulp
section
response
to Enamelite
of an Enamelite (1 week) dentin; and P, pulp.
R, remaining
restorations
specimen (Original
45
showing magnifi-
4. A photomicrograph of a histologic section of a ZOE (6 week) specimen showin g reparaand a lack of a deep inflammatory response. A slight superficial r( 5sponse is de mtin formed en1t. R, reparative dentin; P, pulp; and D, primary dentin. (Original magnificatic m x250.)
46
Amet and SaysgIl
Fig. 5. A photomicrograph a very mild superficial is present. D, primary x250.)
of a histologic section of an Enamelite (6 week) specimen showing response and lack of a deep response. Well formed secondary dentin dentin; R, reparative dentin; and P, pulp. (Original magnification
the Enamelite. The average degrees of superficial response were comparable, with 0.60 for the ZOE and 0.62 for the Enamelite. None of the ZOE specimens showed deep inflammatory responses at the 6 week postoperative period (Fig. 4). This was also true for the .6 week postoperative Enamelite specimens (Fig. 6). Reparative dentin formation was good for both materials at the 6 week period (Figs. 4 and 6). Hemorrhage was comparable for both materials. DISCUSSION When the literature related to the biologic effects of restorative materials is critically reviewed, the great variability among the findings of investigators is SO noticeable that it is not surprising that diverse conclusions have been reached. HOWever, the essential points of these experiments should not be overlooked when interpreting the validity of the conclusions. Different experimental methods are a partial cause of this diversity, and they make it difficult to compare results of various investigators and to decide whether any particular work has been adequately confirmed. The remaining dentin thickness is considered to be a crucial factor when investigating pulp response.“. (i According to Stanley,7, s 2 mm. of dentin thickness will provide an adequate insulating barrier against toxic elements. Langeland and Langelandlo found that a thick layer of dentin does not necessarily protect the pulp, and severe reactions may occur even if cavities are shallow. In their study of composite materials, Langeland and associates” found moderate and severe pathologic reactions in spite of thicknesses of up to 2.1 mm. However, Sayegh and Reed”. I1 have shown that the remaining dentin in rhesus monkeys should be less than that in human beings if the results of these two types of studies are to be correlated. Thus, in the present
Pulp response to Enamelzte restorations
47
Fig. 6. A photomicrograph of a histologic section of an Enamelite (6 week) specimen showing a lack of a deep inflammatory response. Well formed secondary dentin is present. P, puIp; 0, odontoblastic layer; R, reparative dentin; and D, primary dentin. (Original magnification x1,000.)
study, the recommendations of Stanley’, 8 were modified so that only sections of remaining dentin of 1 mm. or less were used in all categories. The remaining dentin thicknesses of all teeth in this study ranged from 0.20 to 1.35 mm. Those teeth with histologic exposure, as determined during the initial microscopic screening, were considered unacceptable. Also teeth with a remaining dentin thicker than 1.0 mm. were similarly eliminated from the study. The remaining dentin was calculated from measurements obtained from all the sections made of each tooth, with the number of sections in some teeth reaching 85. The Enamelite produced three abscesses in the I week period when the remainthat are ing dentin was 0.3 mm. or less. Th is indicates the presence of ingredients toxic to the pulp if there is little remaining dentin to protect the pulp tissue or if the material is placed directly over an exposure. The degree of the inflammatory response in this investigation for the 6 week Enamelite group was milder than that reported with other composite resins.“, ‘. ” The fact that no significant reactions were observed in this group does not mean that composite resins should be used without a liner, as recommended for Addent 3513, 14; they should be used with a liner. The possibility of an undetected pulp exposure when preparing a deep cavity must not be overlooked.” This situation could account for the three abscesses in the 1 week specimens. Therefore, it is recommended that every deep cavity preparation be treated as a potential pulp exposure by placing a protective barrier that will seal the .involved dentinal tubules. This agrees with the recommendation of StanleyI” that until other liners have been studied more extensively, a calcium hydroxide liner is the best protection under composite restorations.
48
Amet
and Sayegh
.J. 1’1oathct. Dent. January, 1917
Finally, poor adaptation represents a serious threat to the pulp, causing more irritation than the actual material. I2 So far as microleakage is concerned, most composite resins are not superior to the conventional resins.17 However, it has been shown that simple acid etching of enamel can increase the adhesion of the acrylic resin filling material and decrease the microleakage.l* The physical properties of the Enamelite material are such that it can easily flow into cavity preparations and take advantage of acid-etched enamel for bonding, as was done in this study to decrease microleakage and resultant pulpal injury. SUMMARY
AND
CONCLUSIONS
The average magnitudes of cellular displacements, superficial responses, and deep responses were less for specimens restored with ZOE than for Enamelite specimens at the 1 week postoperative period, Of 20 teeth treated, three abscesses were found in the 1 week Enamelite postoperative period when the remaining dentin was 0.3 mm, or less. This indicates the presence of ingredients that are toxic to the pulp when there is little remaining dentin or when the material is placed directly over an exposure. Teeth restored with Enamelite in the 6 week group had values comparable to the ZOE teeth for the same time period. References 1. Chang, R. W. H., Dahlman, K. E., and Ruth, J. T.: Properties of Glass-Reinforced Polymeric Material for Dental Filling, Int. Assoc. Dent. Res. Abst. No. 182, July, 1965. 2. Langeland, I,. K., Guttuso, J., Jerome, D. R., and Langeland, K.: Histologic and Clinical Comparison of Addent With Silicate Cements and Cold Curing Materials, J. Am. Dent. ASSOC. 72: m-m, 1966. 3. Fillerbrown, F. G. : Plastic Fillings, Dent. Items Int. 12: 312, 1890. 4. Shroff, F. R.: Effects of Filling Materials on the Dental Pulp. A Critical Review, J. Dent. Educ. 16: 246-259, 1952. 5. MrCurdy, C. R., Swartz, M. I,.. Phillips, R. W., and Rhodes, B. F.: A Comparison of 111 Vivo and in Vitro Microleakage of Dental Restorations, J. Am. Dent. Assoc. 88: 592-60’2, 1974. 6. Stanley, lI. R., Swerdlow, li., and Buonocore, M. G.: Pulp Reactions to .4nterior Re$torative Materials, J. Am. Dent. .4ssoc. 75: 132-141, 1967. 7. Stanley, H. R.: Design for a Human Pulp Study. Part I, Oral Surg. 25: 633-647, 1968a. 8. Stanley, H. R.: Design for a Human Pulp Study. Part II, Oral Surg. 25: 756-764, 1968b. 9. Sayegh, F. S., and Reed, A. J.: Analysis of Histologic Criteria Commonly Used in Pulp Studies, Oral Surg. 37: 457-462, 1974. 10. Langeland, K., and Langeland, 1~. K.: Pulp Reactions to Crown Preparation, Impression, Temporary Crown Fixation and Permanent Cementation, J. PROSTHET. DENT. 15: I29143, 1965. 11. Sayegh, F. S., and Reed, A. J.: Critique and Comparison of Pulp Responses in Monkey and Human Teeth, Int. Assoc. Dent. Res. Abst. No. 525, March, 1970. Pulpal Reaction to Composite Resin Restorations, J. 12. Brsnnsttim, M., and Nyhorg, H.: PROSTHET. DENT. 27: 181-189, 1972. 13. Russell, J. R., Grove, D. M., and Cotton, W. R.: Pulp Response in Rat Molars to a New Restorative Material, Oral Surg. 24: 253-262, 1967. of the Human Pulp to a New Restorative 14. Baume, I.. J., and Fiore-Donno, G.: Response Material, J. Am. Dent. Assoc. 76: 1016-1022, 1968. 15. Hassan, E. H., Van Huysen, G., and Gilmore, H. W.: Deep Cavity Preparation and the Tooth Pulp, J. PROSTHET. DENT. 16: 751-755, 1966.
$3hm&
;1
”
16. 17. 18.
Pulp
response
to Enamelite
restorations
49
Stanley, H. R.: Pulpal Response to Dental Techniques and Materials, Dent. Clin. North Am. 15: 115-126, 1971. Phillips, R. W.: Report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry, J. PROSTHET. DENT. 23: 665-690, 1970. Buonocore, M. G., Matsui, A., and Gwinnett, A. J.: Penetration of Resin Dental Materials Into Enamel Surfaces With Reference to Bonding, Arch. Oral Biol. 13: 61-70, 1968. DR. AMET 911 MAIN ST. COMMERCE TOWER KANSAS CITY, MO.
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DR. SAYECH UNIVERSITY OF MISSOURI-KANSAS SCHOOL OF DENTISTRY KANSAS CITY, MO. 64108
ARTICLES
CITY
TO APPEAR IN FUTURE
A new semiadjustable articulator. capability of the Hanau XP-51 Israel
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