A versatile restorative material for occlusal cavities

Operative dentistry

A versatile Newell

0.

restorative

Feeley,

material

for occhsal

cavities

D.D.S.

Topeka, Kan.

S

hortly after World War II, the U. S. Armed Services released captured German documents of scientific interest. Among them, the formula for the first autopolymerizing (cold-curing) resins created much interest within the dental profession. In the late 1940’s, industry introduced an autopolymerizing acrylic resin for dental restorations in anterior teeth. Dentists received the new resin with hopeful enthusiasm as a replacement for silicate cement. Initially pleasing in appearance, the new plastic lacked color stability. The first published experimental studies in 1949 were quickly followed by other more critical evaluations that revealed the thermal coefficient of expansion of acrylic resins to be seven times that of tooth enamel12 2 Marginal leakage and percolation, due to the high level of expansion and contraction of the restoration, resulted in pulpal irritation and failure.3 Industry knew how to solve the problem of excessive thermal expansion. All resins contained fillers and coloring materials. The rate of thermal expansion could be controlled by increasing the quantity of filler in the resin. Unfortunately, the amount of filler required to correct the thermal expansion impaired the color value of the restorative material. The autopolymerizing resins lost favor for use in anterior teeth. Paffenbarger and co-workers,4 in 1953, suggested that the direct-filling resins would not serve as adequate replacements for metals and alloys in operative dentistry. Since that time, numerous attempts have been made to incorporate glass fibers or beads as fillers. None of these products had properties that approached the physical properties of silver amalgam.5 Recently introduced as a restorative material for posterior teeth, Addent 12* (for Class I and II cavities) has revived interest in a composite resin restorative material suitable for use in molars and bicuspids. The material is physically stable, and the esthetic value is higha COMPOSITION Addent a “binder.” *Dental

OF ADDENT

12

12 is a cold-curing resin that contains a resinous portion, referred to as The resinous portion constitutes 28 per cent of the material and is a Restorative

System, 3M Dental

Products,

St. Paul, Minn

489

\. alrd water absorption. ‘I’h<> rr~~nainirlg 72 pc’ c(‘nt of t tI(a rcastorati\.r n~att~rial i< cl powcirrc~l ctSramic This powdered ceramic has been \vittl a lo\v coc*fficicnt of th(%rmaI cspansion. (\irlyI-silanc” / which allows the treated \\itlr a \\;rt~r.-r.t,pc~lIrrrt couplinp ayrrlt filler’s surface to c-ht~micaIl~~ react smith the or,canir hindt*r during setting to form a strorii_: rnoist~rI.~‘-resistarit bond. One ~ror~p of irr\.estigators repol,ttd that the rnat~rial had good color value and of acquired only surface stain. ‘I’hrs margins of the restorations and the adaptation t tie material to the pulpal fall were satisfactory.’ The filler and binder, rrrixcbd to a doughy consistency. are packaged in individual portions. Each portion requires only one uniform drop of catalyst from the dropper bottle to activa.tc the self-pol~rrrerizirrg r&n.

complex

PHYSICAL PROPERTIES OF ADDENT

12 AND AMALGAM

Since this report is limited to Class I restorations, the comparison of the properties of Addcnt 12 \vith arnal‘gam is confined to the Class 1 restoration. Solubilit). Both materials arc insoluhlc in saliva. (.‘or~LJJrmii’f~ nncl trmilcs T~YI~JI,@~,Both rnaterials poswss sufficient strength 10 resist ordinary occlusion stresses. Amalgam is stronger.’ Linc,ar c.oc$%%~rf (,I I/!~rrnnl /X/JC&O?/. Addent I ‘1 i has a lower coefficient of therrnal expansion than amalgam.” Flout. Amalgam tends to flow unclc~~ stress ; 3 to 5 per cent 1 creating marginal irregularities. Addent 12 showy less flow undtar stress ( 1 per cent’). Thermal and c,lrctrical ioudurtirit~~, None in Addent 12. CLINICAL COMPARISON

OF ADDENT

12 AND AMALGAM

Addent 12 offtbrs many clinical advantages to the dentist. The material is quickl) and easily inserted into the tooth cavity; it hardens rapidly: it may be finished immediately; a.nd its tooth color is pleasing to patients. Compared with amalgam. Addent 12 offers sctveral aclvantagcas. 1:‘a.w of manipulation aud inrt~rtiou. Arnalgarn must be carefully condensed against the \valls of calities and plashy portions must be removed. Addent 12 may be inserted in bulk into the cavity: condensation is unnecessary. Essth&c. Amalgam, affected by chemical and galvanic reactions, corrodes, causing unsightly discoloration of dentin and enamel. Addent 12 (a tooth-colored material) does not discolor dentin and t~narrrrl. The rnaterial may be stained to achieve greater color harmony, Rnpid initial Tc~t. In t to IO minutes. Addent 12 attains sufficient strength to minimize the danger of material fracture under occlusal stresses : amalgam requires many hours to achie\,tl strength equal to it. The quick-setting factor is a si,gnificant advantage where rapid insertion is imperatik V.

Volume 19 Number 5

Restorative

material

for

occlusal

cavities

491

Abrasion resistance. Addent 12, under certain abrasion tests, has greater resistance to occlusal abrasion than ama1gam.l” Finishing. Compared to amalgam or restorative materials which contain a low percentage of inorganic filler, Addent 12 cannot be made to reflect a high polish. It can be finished immediately following insertion, and the occlusal margins can be dressed to form a smooth butt joint with the cavosurface margin. The dull appearance of the dry restoration is due to the physical nature of the ceramic filler which lacks surface reflectance. MAINTAINING

DRYNESS

Addent 12 may be inserted in a variety of ways, permitting the dentist to select a method suitable to the needs of the tooth. Burlew Dryfoil” is routinely used to exclude moisture. This material is a dead pack adhesive tinfoil that, for many years, has served to exclude moisture from restorations or from treatments. When used with Addent 12, Burlew Dryfoil will adhere to the tooth and filling, exclude moisture while the filling sets, and provide a finished occlusal surface requiring minimal adjustment. METHODS

OF INSERTION

This report offers two methods of inserting Addent 12 into a Class I cavity. manufacturer’s instructions describe other methods. The dentist must insert Addent 12 in bulk and retain the restoration in field under pressure. Since the material must polymerize before the pressure moved, the techniques should include restoring the anatomy of the tooth and mal finishing operations. THE MODELING

PLASTIC

The a dry is remini-

MATRIX

The dentist should prepare the matrix before commencing the preparation of the filling material. The matrix, made of red stick modeling plastic, may be reinforced with pieces of a tongue blade. Reinforced lengths of modeling plastic varyinq from s/a to lyz inches may be prepared in advance, Pointing or rounding one end of the wooden reinforcement, which is directed anteriorly, will make for quick orientation when applying the matrix to the tooth. Where the occlusal cavity has acceptable anatomy, the modeling plastic should be softened without causing tackiness, and the softened matrix is then seated over the tooth to be restored and also over the adjacent teeth. The pointed or rounded end of the reinforcement should be directed anteriorly, and pressed firmly to secure a precise impression (Fig. 1) . Th e matrix is removed and the excess trimmed. Burlew Dryfoil is adapted to the matrix by finger pressure, with the adhesive side toward the modeling plastic. The matrix is replaced on the tooth and pressed in place to complete the adaptation of the foil (Fig. 2). In teeth with large carious voids, or missing parts, the tooth’s anatomy should be restored before making the matrix. The voids may be filled with gutta percha or DuraSeal Plastic Stopping.? DuraSeal may be contoured and smoothed with a slowly *Burlew +Reliance

Dryfoil Dental

(regular),

J. F. Jelenko

Mfg. Company,

& Company,

Chicago,

111.

Inc., New York, N. Y.

Fig.

Fig. 1. Before prepariqp

tli~ c,a\.ity.

ihv rvinforcrd

plastic

i< sk~frrnrd

and pressed 0vpr th(

teeth to form a matrix.

Fig. 2. The modrling face of the tooth.

plastic matrix. l)rytoil has lwcn roughly adapted over the oc~lusal surand the matrix has I)~cw returned to the tooth to complete the adaptatirjn.

rcvolvirig round bur- (Fiff. 3 j ‘l‘he matrix is made after restoring the anatomy of thC tooth. The surface irregularities in ttw matrix arr corwctcd with a spoon excavator or c‘arvcr. The matrix is completed hv adapting the Rurl~~w Dryfoil. PLACEMENT

OF ADDENT

12

The instruruents and the foil-cowwcl rnatris should be readily available. A large stellite or stainless stwl spatula is best for mixing Addcnt 12, and a flat-bladed plastic instrumr:nt is necdrd for insrrtion of the* rcstorativc material into tht= cavity. An intermediate base i< inserted if necessary. Zinc oxide and eugenol should not be uwd becauw cugenol ath~c~rsc~lyaff‘cctb .4ddcnt 12. A calcium hydroxide base such or Pulpdtwtt may tw ~wtl. 1)11t .4ddcnt cavity liner tnust be used over as Hydrcs” the intcrmediatc baste Addent 12 is mixed acc‘orclirlg to t 11~manufacturer’s dirwtions. and inserted in bulk to fill the cavity i Fig. I I. *Hydrrx tPulpdent

C:alrium

IHydroxide

Pastrr-Ca!

t’rcparatioll.

OH) 1, Pulpdent

Kerr Mfg. Compa~~y. Drtroit, C:orp. of America,

Boston, Mass.

Mictl.

Volume 19 Number 5

Restorative

material

for

occlusal

cavities

493

B

Fig. 3. Large carious voids or missing parts of teeth may be temporarily restored before the matrix is made. The temporary restorations may be made of’ (A) gutta percha, which is difficult to smooth, or (B) DuraSeal, which may be easily contoured with a round bur and removed with a warm instrument.

Fig. 4. Addent

12 is inserted in bulk into the cavity

with a small spatula

The foil-lined matrix is quickly placed in position sure is applied until the material sets, usually in 3 to usually sufficient, but a cooperative patient may be matrix in place (Fig. 5). The matrix may be removed as soon as the initial adheres to the tooth and may be left in place for an assure adequate curing time (Fig. 6). The restoration to finish. THE FINGER

on the tooth, and mild pres6 minutes. Finger pressure is asked to close and hold the set occurs. The foil usually additional 2 or 3 minutes to is now complete and ready

MATRIX

A preformed matrix is not always indicated, particularly in teeth where the cavity is small or narrow, such as in bicuspids, deciduous molars, or molar pits and fissures. In such instances, the fleshy pad of the finger or thumb pressed over a layer

;ig. 6

,ddj Fig. 5. toot hc *ve r it Fig. 6. 7 ‘1)c thr tot 1th an

ted On thr ,te

that

of Dryfoil adapts readily to the anatom) of the tooth to form a most adequate matrix for the confinement and adaptation of an Addent 12 restoration during thr setting period. Since this method readily permits the restoration of two or more cavities with a single mix of Addent 12, the slower setting one-drop mix should be employed. The material is placed in bulk into thr ca\+ty, covered with an oversized piece of Dryfoil, and with a rapid and firm rolling pressure of the pad of the finger, the material is quickly distributed, and the excess is pushtld aside (Fig. 7 I. In the event of deep tooth anatomy and a narrow cavity, a small piedget of cotton placed over the Dryfoil will aid in shaping the occlusal surface of the restoration. Fig. 8 shows two approximating maxillary bicuspid teeth restored with Addent 12. Part of the Dryfoil has been rerno\.ecl to dthmonstrate thr excess flash lvhich lnay be quickly and easil) snappcad off. Fit. 9 shows how a small cotton roll was used to maintain occlusal pressure on upper and lower teeth after using fin,qer pressure on both teeth.

Volume 19 Number 5

Restorative

material

for

occlusal

cavities

495

Fig. 7

Fig. 8

Fig. 9

Fig. 7. The finger matrix. Finger pressure may be applied over a layer of Dryfoil Addent 12 throughout the cavity and serve as a moisture barrier. Fig. 8. The finger adjacent

matrix is used to distribute a single mix of Addent teeth. Note the flash of the excess restorative material.

Fig. 9. Four upper and lower bicuspid mix of resin and a finger matrix.

to distribute

12 in cavities

teeth with Class I cavities were restored A cotton roll was used to maintain pressure.

with

of two a single

FINISHING THE RESTORATION A polished dental restoration usually exhibits a high degree of luster, which results from the reduction of surface imperfections. Addent 12 is a heavily loaded composite consisting of microscopic islands of hard ceramic filler (the interstitial spaces occupied by softer epoxy-acrylic resin binder). This composite cannot be finished to a metallic luster or the glossy shine of a softer acrylic resin, but Addent

496

Fwlq

Fig. 10. Instruments used for finishing Addent 12 (left to right) : ( 1 ) Thompkir the thin Aash of restorative material: (2) discoid-cleoid amalg for removing (3) prophylaxis brush for use with abrasive pastes; (4) scra ping or planing: and ! 61 rubber snap-on cone for use ston e: (5) bur lor occlusal adjustment: past es for the final finishing.

i scaler, useful m carv er fol mall m( ,unted with at )rasivr

Fig. 11

Fig.

Fig. 11. A round amalgam carver is being used to scrape margins of an Addrnt Fig. 12. An abrasive pastr is used for the final smoothing of the restoration.

2 rest01 .ation.

Restorative

material

for occlusal

cavities

497

12 can be finished to a satisfactorily smooth surface that will remain clean and stain resistant7 Attempts to polish Addent 12 have emphasized the need for instruments and materials specifically designed to finish the occlusal surfaces of restorations in bicuspids and molar teeth. The following are suggested: ( 1) A scraper or carver designed for planing the margins of the restoration should be made of a hard steel such as carbide, because the abrasiveness of the ceramic filler quickly dulls ordinary amalgam carvers. A sturdier design than those now available would be desirable. (2) Rotating plastic points that would carry abrasive pastes of various grits for smoothing the occlusal surfaces of restorations could be made interchangeable with snap-on or screw-on prophylaxis polishing cups. (3) Abrasive pastes of sufficient grit to reduce remaining surface irregularities and to smooth the restoration could be used. FINISHING

TECHNIQUE

If the compound matrix or finger matrix technique has been used, the thin flash of excess restorative material is removed with a sharp instrument, such as a Tompkins scaler or a gold knife. A small stone or plug finishing bur running at slow should be speed is used to adjust the occlusion. The margins of the restoration avoided in this procedure. If the material has been placed in bulk into the cavity without a matrix, the anatomy of the restoration is carved with a small stone or finishing bur. Slow rotational speed is used, and the margins of the restoration are avoided (Fig. 10). The stones and burs should be lubricated with Addent wax. The margins of the restoration are scraped to the tooth level with a hand instrument such as a discoid-cleoid amalgam carver (Fig. 11). The jagged end of a broken angle instrument or a B scaler are effective in the removal of flash from small areas such as auxiliary grooves. There is no indication of any tendency of the material to fracture below the cavity margin during the scraping process. Cavity margins present a satisfactory butt joint between the tooth and the restorative material. A polishing cone or brush and a suitable abrasive plate will complete the restoration (Fig. 12) . Fig. 13 shows two Class I molar restorations 13 months after insertion. DISCUSSION When first introduced, the setting time of Addent 12 presented a problem. Recently, the manufacturer perfected a catalyst dropper-tip bottle which minimizes the problem. Changes in the concentration of the catalyst and the dropper-tip design permit a smaller drop of catalyst to a packet of Addent 12 to be used for a longer working time. Two drops of catalyst hasten the reaction. Control of the curing time permits the necessary accommodation for climatic changes. Addent 12 is a versatile restorative material. As such, it lends itself to the various needs in dentistry. The material is effective in prophylactic odontotomyll (Fig. 14). Prophylactic odontotomy may be readily accomplished with the finger pressure technique. Addent 12 merits consideration for difficult situations. Amalgam requires meticulous cavity preparation and condensation; both are time-consuming. For the

498

I 1’10s. Dent. May, i!%S

Feeley

Fig. 13. ‘Two molar modeling

rrstor;ltions plastic matrix,

made front

;L single

mix

of .4ddrnt

12 with

the aid 01 ,I

Fig. 14. A cross section of a bicuspid tooth with a reinforced modeling plastic matrix Note thr distribution of thr resin in the cavity and the thinness of thr flash.

in place.

mentally or physicallv handicapped. the small child. or the patient who gags, hddent 12 offers advantages. Cax.ity preparation may he minimal, and the quick insertion and rapid set are advantageous. For the aged, who still have a few sharp-edged teeth and for whom prosthetic service is contraindicated. the teeth ma]; he restored and rounded off to a comfortable smoothness. Addent 12 is new. ‘l‘imc and trial will justify its use, SUMMARY

AND

CONCLUSIONS

Addent 12 is a versatile rrstorati\,e material for use in selected operative situations. This report describes two techniques for its USC in CXass I cavities. In restorations in Class II cavities. it shows promise: but further observations and testing are needed to determine its acceptability.

Restorative

material

for occlusal

cavities

499

Emphasis has been placed on the use of a matrix system as a means of confining the plastic mix during the setting period and, at the same time, forming the occlusal anatomy of the restorations. Burlew Dryfoil establishes a reliable moisture barrier for the material and becomes a useful aid in forming the restoration. The feasibility of making a finished restoration in one sitting has advantages to dentists in situations where the patient may not be seen again. References 1. Lefkowitz, W., Seelig, A., and Zachinsky, L.: Pulp Response to Self-Curing Acrylic Filling Material, New York D. J. 15: 376386, 1949. 2. Coy, H. D.: Direct Resin Fillings, J. A. D. A. 42: 532-537, 1953. 3. Nygaard-Ostby, B.: Pulp Reactions to Direct Filling Resins, J. A. D. A. 50: 7-13, 1955. 4. Paffenbarger, G. C., Nelsen, R. J., and Sweeney, W. T.: Direct and Indirect Filling Resins; A Review of Some Physical and Chemical Properties, J. A. D. A. 47: 516-524, 1953. 5. Peterson, E. A., Phillips, R. W., and Swartz, M. L.: Comparison of the Physical Properties of Four Restorative Resins, J. A. D. A. 73: 1324-1336, 1966. 6. Phillips, R. W.: Recent Improvements in Dental Materials That the Operative Dentist Should Know, J. A. D. A. 73: 84-90, 1966. K.: Histological and 7. Langeland, L. K., Guttuso, J., Jerome, D. R., and Langeland, Clinical Comparison of Addent With Silicate Cements and Cold-Curing Materials, J. A. D. A. 72: 373-385, 1966. 8. Hollenback, G. M., Villanyi, A. A., and Shell, J. S.: A Report on the Physical Properties of a New Restorative Material (Addent), J. Southern California D. A. 34: 250-255, 1966. 9. Going, R. E., and Sawinski, V. J.: Microleakage of a New Restorative Material, J. A. D. A. 73: 107-115, 1966. 10. Shell, J. S., Hollenback, G. M., and Villanyi, G. M.: Comparative Abrasion Rates on Restorative Materials, J. Southern California D. A. 42: 521-524, 1966. 11. Hyatt, T. P.: Prophylactic Odontotomy, an Operative Procedure for the Prevention of Decay, D. Cosmos 65: 234-241, 1923. 4125 GAGE CENTER DR. TOPEKA, KAN. 66604