The use of a direct bonded microfilled composite resin veneer

The use of a direct bonded microfilled composite resin veneer

C L I N I C A L T E C H N I Q U E S The use of a direct bonded microfilled composite resin veneer T h o m a s D . L arson , D D S , M SD C raig B. ...

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C L I N I C A L

T E C H N I Q U E S

The use of a direct bonded microfilled composite resin veneer

T h o m a s D . L arson , D D S , M SD C raig B. P h air, D D S, M S

e fo re 1974, th e o n ly m e th o d s available to im prove the app ear­ ance of discolored anterior teeth were tem porary acrylic jackets, porcelain jack et crow ns, an d porcelain-fused-tom etal restorations. T h e developm ent of the acid-etched enamel technique by Buono c o re 1 a n d th e B IS /G M A -based c o m ­ posite resin by Bowen2 m ade possible the d ir e c t b o n d in g o f c o m p o s ite r e s in veneers3,4 to the facial surface of stained teeth, p ro d u cin g an esthetic appearance. S u b s e q u e n tly , in d ir e c t la b o ra to ry m ethods were developed using acrylic5,6 or porcelain veneers.7 Direct m ethods for b o n d in g o f v e n e e rs h a v e im p r o v e d th ro u g h etch in g the enam el, interm ediate bo nding, and the developm ent of m icro­ fille d , v is ib le lig h t-c u re d c o m p o s ite resins, opaquers, and tints. In their survey of dental p atien t a tti­ tudes, G o ld stein an d L an caster8 found that 41% of respondents w ould like to change th eir smile. O f those respondents h aving teeth bonded w ith com posite m a­ terials, 97% said they were satisfied to e x tre m e ly s a tis f ie d w ith th e r e s u lt. Patients surveyed chose bond in g of com ­ p o site m a te ria ls because they believed b o n d in g was a m ore conservative, less drastic, an d less expensive procedure than u sin g p o rcelain crowns. C hristensen9 has

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in d ic a te d th a t o n e -a p p o in tm e n t m icro­ filled resin veneers are favored by the clinicians he surveyed. Also he reported that u sin g total opaquers w ith a m icro­ fille d re sin veneer are o p tim a l w hen covering a m etallic surface. Jo rd an and o th e rs 10 investigated u sin g lab ial com ­ posite resin veneers to alter the enamel shade but found a distinct problem with the technique. A pparently, the translucent m icrofilled resin veneer allow ed “shineth ro u g h ” of un d erly in g tooth discolora­ tion or opaq u ed teeth. A clinical tech­ n iq u e w ith o u t these draw backs th at cre­ ates a veneer w ith a lifelike color and appearance is explained in this report.

Methods and materials The repeatable veneer

Direct bonded, composite resin veneer ap p li­ cations should be relatively sim ple, co n ­ sistent, and predictably replicable. If the results of the procedure are predictable, the c lin ic ia n can discuss the pro b ab le outcom e of the procedure w ith the p a­ tient. T h e procedure m ust be sim ilarly repeatable because often two central and two lateral incisors an d two canines are involved in the color change. T h e central

incisors m ust ap p ear sim ilar to each other to look n atu ral after veneering. T h e final shade of the veneer sh o u ld m atch the com plex d istrib u tio n of color found in a n atu ra l to o th as seen from a distance. In ad d itio n , the procedure sh o u ld be com ­ pleted w ith in a reasonable tim e (w ithin 30 m in u te s). T h e p referre d te c h n iq u e allow s the clin ician a variety of o p tio n s in re sto rin g teeth, from severe d isc o l­ o ra tio n to m ild ly h y p o p la s tic enam el. V isible light-cured com posite resins are preferred for this technique because they are less porous, m ore color stable, an d m ore adaptable to different clinical situ a­ tions, a n d can be layered to achieve the desired n atu ra l ap p earan ce.11 T o restore the facial surface of an an terio r to o th a n d to replicate the surface texture, reflectivity, and, o p tim ally , the o p tical properties of the enam el it covers or replaces, m icrofilled com posite resin is preferred. D epending on how the m a n u ­ facturer has loaded the m icrofilled com ­ p o s ite re s in w ith fille r p a rtic le s , the m a te ria l w ill vary in tran slu ce n cy ac­ c o rd in g to its th ic k n e s s .12 M ic ro filled com posite resins are p o lish ab le a n d can closely rep licate th e surface te x tu re of en am el.11,13 T h e clin ician m atch in g the color of the a d ja c e n t teeth w ith th e veneer sh o u ld JADA, Vol. 115, September 1987 ■ 449

CLINI CAL

T E C H N I Q U E S

view the incisal th ird contralateral tooth for m odeling the enam el co lo r.11 T here is little d en tin here, an d m ostly enam el to m atch. T h e shade chosen for the veneer sh o u ld be equal or h ig h er value than the d esirab le color of the n a tu ra l tooth. S q u in tin g can h elp w hile choosing the color. T h e shade tab sh o u ld be held behind

rather th an lifelike and vital. T h is dead appearance of the tooth color occurs be­ cause the op aq u e m aterial either absorbs o r reflects the w avelengths of lig h t rather th a n ju s t tra n sm its th e lig h t as does n a tu ra l to o th stru ctu re . A lifelik e a p ­ pearance is achieved by u sin g tints to m odify the w avelength of lig h t as it is transm itted th ro u g h the m icrofilled com-

D ire c t bonded, composite resin veneer applications should be relatively simple, consistent, and predictably replicable.

the to o th to be m atched so the viewer can see if the colors blend together. In this respect, m atching shades for com posite resin s is d ifferent from m a tc h in g p o r­ celain shades to teeth. W hen m atching porcelain shades, the viewer is looking at a shade tab th at is polychrom atic, as is th e to o th . W hen m a tc h in g co m p o site shades, the viewer is lo o k in g a t a m ono­ chro m atic shade tab and a polychrom atic tooth. T herefore, w hen m atching com ­ posite shades the clinician should look for a blend of colors rather th an an exact m atch. After the hue of the shade is de­ term ined, the viewer should identify the difference in chrom a between the shade tab an d the tooth. T h e clinician should analyze w hich shade has m ore yellow. T h e color w ith h ig h er value is identified by s q u i n t i n g to see w h ic h c o lo r is b rig h ter an d w hiter. T h e shade chosen sh o u ld be of equal or h ig h er value. After the deviation of the color m atch of the com posite resin from the tooth is iden­ tified, tints can be used to m odify the color of the com posite resin .11 At this p o in t, the p ractitioner should consider u sin g an opaquer. O paque com ­ posite resins block the transm ission of lig h t w av e len g th s. T h is p re v e n ts th e co lo r beneath the o p aq u e m aterial from being visible. As w ith com posite resin overlays, the color of the o p aq u e m aterial sh o u ld m atch the h u e of the tooth to be created. T h e op aq u er creates the necessary b ack g ro u n d color, a n d acts m uch like a c a n v a s fo r a p a in tin g . It allo w s the c lin ic ia n to create d e n tin a n d enam el color effects w ith tints rath e r than w ith th e o p a q u e r . O p a q u e r used a lo n e to create d en tin or enam el color will make the tooth color app ear nonvital or “dead” 450 ■ JADA, Vol. 115, September 1987

p o site resin c re a tin g the illu sio n of a depth of color. For difficult color m atch in g or when six o r m ore veneers are to be placed, a color m ockup can be applied, allow ing the p atien t to approve the shade choice. T h e m ockup is done w ith o u t acid etching a n d by a p p ly in g th e m a te ria ls in se­ quence to create veneer color. T h is p ro ­ cedure also allow s the clin ician to verify a p p r o p r ia te tin t a n d o p a q u e choices. T h is m ockup veneer is easily pried from the tooth. T h e app ro p riate color choices for the p a tie n t sh o u ld be recorded in the p a ­

ara tio n to h alf of the thickness of the enam el. T h e y believe th a t to o th p re p ­ a r a tio n e n h a n c e s th e r e te n tio n a n d m a rg in a l s tre n g th of th e re s to ra tio n . W ith o u t q u e s tio n , enam el p re p a ra tio n helps to reduce possible excessive co n ­ to u rs of th e re sto ra tio n w h ich can be dam aging to gingival health. C hristensen9 reported that, in m any cases, rem oval of tooth stru ctu re may n o t be required. T h e direct-bonded veneer in m ost cases w ill be 0.5 to 1.0 m m in thickness. T h e thickness w ill vary according to w hether an o p aq u e m aterial is added. If either the dentist or the p a tie n t objects to the ad d itio n al b u lk , the tooth sh o u ld be prepared. If a p rep ­ aratio n is done, a diam o n d b u r is recom ­ m ended to provide a cham fer fin ish in g m argin. T h is m arg in should be prepared to extend to the level of the gingival crest an d ju s t facial to the p ro x im al contacts areas. Veneer placem ent requires a dry field for p ro p er etching, bonding, an d resin placem ent. T h e heavy rubber dam has been recom m ended by C hristensen9 an d Jo rd an and o th ers10 as a time-effective te c h n iq u e for is o la tio n . G in g iv a l re ­ traction w ith this m ethod is achieved by u sin g a no. 212 clam p, an d gingival re­ traction cords are also suggested. Both of these te ch n iq u e s expose the field ade­ q u ately an d usually m a in tain the desired dryness. In some patients, however, these p ro ce d u re s can re q u ire an an e sth e tic . B e lv e d e re a n d L a m b e r t 14 s u g g e s t a

W ithout question, enamel preparation helps to reduce possible excessive contours of the restoration which can be damaging to gingival health.

tie n t’s chart so th a t the procedure may be repeated at a later date if necessary.

Tooth preparation T h e placem ent of the gingival m argin of the restoration, the type an d color of the disc o lo ratio n b ein g covered, the a lig n ­ m ent in the arch, the in clin atio n of the tooth, an d the use of an o p aq u er should be considered w hen deciding w hether the tooth should be prepared. W hen enamel r e d u c tio n is n e c e s s a ry , J o r d a n a n d o thers10 recom m end that the enam el be prepared w ith a cham fer shoulder p rep ­

V ivadent C o n to u r Strip to isolate a single to o th to re fle c t th e g in g iv a l tis su e , m a in ta in a d ry field , a n d p ro v id e a finished subgingival m argin. T h is a p ­ p roach can save the clinician tim e in isolation procedures an d in fin ish in g the gingival m argin. P atients seem to prefer contour strips as they are less intrusive and m ore com fortable th an the rubber dam or placem ent of gingival retraction cords. Also, they require no anesthetic. If the tooth was n o t prepared w ith a d ia m o n d b u r, th e e n a m e l s h o u ld be c le a n e d w ith f l o u r o f p u m ic e a n d w ater.9,10 T h e pum ice should not contain

CL INICAL

flu o rid e . T h e e n a m e l of m o st te e th should be etched for 60 seconds and in ­ c re a se d by 3 0 -se c o n d in c re m e n ts in fluoresced teeth. A 30% to 40% p h osphoric acid liq u id or gel-type etchant is often used. Gel etchants are difficult to remove from the surface b u t m ust be thoroughly rinsed from the tooth (45 seconds) as no residual acid can rem ain w hich w ould interfere w ith the qu ality of the bond to the enamel. T h e etched enam el surface

m aterial contacts the strip, a m eniscus is formed, allo w in g the o p aq u e r to extend to th e surface of the veneer. T o look realistic, the o p aq u e r m ust be entirely covered by th e m ic ro fille d co m p o site resin. T h e o paq u er should be thoroughly lig h t cured, leaving a layer of u n p o ly ­ merized resin—the air-in h ib ited layer. If this air-in h ib ited layer is disturbed, for exam ple, by the need to remove some of the o paquer, the cu t resin surface should

I

he subtle developmental depressions and convexities found in natural teeth should be imitated in the veneer to make the result appear normal.

m u st th en be m e ticu lo u sly d ried w ith o ilfree air. A frosty-w hite o p a q u e a p ­ p e a ra n c e o f th e e n a m e l is a g e n e ra l g u id e lin e to signify ad eq u ately etched enam el. Interm ediate bonding com posite resins are carefully placed on the etched enam el. Many of these are BIS/G M A com posite resins w ith a dilu en t added to adjust the viscosity and allow the com posite resin to flow easily. After the resin is placed, all the excess bond in g resin is blow n from the enam el surface w ith dry air to m in ­ im ize the thickness of the m aterial. Many m a n u fa c tu re rs recom m ended th a t the b o n d in g com posite resin be first lightcured before ad d in g a d d itio n a l resin. However, Mowery and others15 found no sig n ifican t difference in the shear bond strength between sim ultaneous an d inde­ p en d en t polym erization of the b o n d in g agent an d the com posite resin. If the decision was m ade to use an o p a q u e r, it sh o u ld be a p p lie d a t th is time. An advantage to having the opaq u er m atched to the same hue as the dentin color is realized as fewer tints are re­ q u ir e d , s u b s e q u e n tly , a n d less c o lo r ad ju stin g is necessary. T h e greater the n u m b e r of d iffe ren t tin ts re q u ire d to m im ic the tooth color, the greater the risk of low ering the value of the color too m u ch . A p a tie n t can u su a lly id en tify value differences of colors easily. T h e o p aq u e m aterial should be applied as thinly as possible over the entire facial surface to block the transm ission of the u n d erly in g color of the tooth structure. T h is ap p lication of opaq u er m ust not contact the m atrix strip or rubber dam used to isolate the tooth. If the opaque

be cleaned w ith an etchant an d a thin coat of com posite resin should be added to im p ro v e th e b o n d s tre n g th to the subsequent layers.16,17 At this stage, tints are used to adjust the chrom a of the dentin hu e an d to deter­ m ine the value of the enam el shade. T in ts can also be used to create m averick color, such as in te rp ro x im a l sta in in g , h y p o ­ plastic spots, and craze lines. Generally yellow, pink, an d orange tints increase the chrom a of the d en tin h u e —th a t is, the color in the gingival h alf of the tooth. If a n a d d itio n a l s a tu ra tio n o f y ellow is necessary, the yellow tin t is used. Pink tin t over a yellow background increases the orange chrom a slightly. O range tint creates an increased orange chrom a over th at achieved w ith the p in k tint. T h is tint is especially useful on canines. W hite, blue, an d gray tints can adjust the value of the color an d create ap p aren t

T E C H N I Q U E S

in c isa l tran slu ce n cy , h y p o p la sia , an d opacity w here needed. Use of the w hite tin t in m oderation can slightly raise the value of the color. Increasing the chrom a of the b ackground color may be more useful in increasing the value, as the ad d itio n of w hite also increases opacity. L ow ering the value of the color is ac­ com plished w ith the use of blue and gray. B lue is th e c o m p le m e n ta ry co lo r to orange, as used in dentistry. If orange is in the background color, blue w ill lower its value because it is the com plem entary color. A violet tin t can be created by m ix in g the blue an d red tin ts together. T h is violet tin t can be used to low er the v alu e w hen th e b a c k g ro u n d co lo r is yellow because violet is the com plem en­ tary color to yellow. H ow ever, this w ill dram atically low er the value. G ray can be used in its place, b u t m u st be used care­ fully because gray tin t w ill dram atically affect the value of the ap p a ren t color. C hrom a of all the tin ts can be adjusted by m ixing the tin t w ith clear com posite resin b o n d in g m aterial. Brow n tin t recreates stains an d check lines an d recreates root color in older individuals. W hen the ap p ro p riate tints have been added, they should be lig h t cured to avoid sm earing. T in ts need be placed only in a th in se c tio n to be effectiv e. P la c in g thicker ap p licatio n s of the tin t w ill affect the chrom a an d value m ore dram atically.

Placement of the microfilled resin T h e m icrofilled com posite resin m im ­ ick in g the enam el shade is placed o n the facial surface. As an advantage of using the V ivadent C o n to u r Strip, it perm its c o n d e n s a tio n o f th e c o m p o s ite re sin alo n g the gingival m argin d u rin g place­ m ent, p rev en tin g the en tra p m en t of air

F ig 1 ■ T h e p reoperative p h o to g ra p h of th is 25-

F ig 2 ■ T h e left central incisor h as been prepared

year-old p a tie n t dem onstrates the e x tent an d p a r­

w ith a 799.MF /im fin ish in g diam o n d bu r. T h e

ticu larly th e low er value of the disco lo ratio n

p re p a ra tio n is extended from the crest of the

e x ten d in g to the crest of the gingival tissue.

g in gival tissue to the incisal edge an d from the m esial p ro x im al c ontact to the d istal p ro x im al contact.

L arson-Phair : USE OF COM POSITE RESIN VENEER ■ 451

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T EC H N I Q U E S

bubbles at the m argin. T h is m ethod of is o la tio n also m inim izes th e need for subgingival finishing. T h e m aterial con­ densed against the facial surface should be w ith o u t air bubbles and should p ro ­ vide adequate thickness (0.5 m m or more) to recreate the enam el and provide the desired contour to the tooth. T h e m aterial is next th oroughly light cured. Because the com posite resin colors are layered rather than mixed, the ability to replicate the final appearance is easier. O nce rec o rd e d in th e p a t ie n t’s c h a rt, la y e rin g of th e v ario u s resin s can be readily duplicated as needed. T h e o riginal enam el texture should be recreated d u rin g the fin ish in g process to create a reflectivity sim ilar to the adjacent n a tu r a l en a m e l. T h e su b tle d e v e lo p ­ m ental depressions and convexities found in n atu ra l teeth should be im itated in the veneer to make the result appear norm al. R o u let an d o th e rs18 recom m end use of d iam o n d burs w ith an abrasive particle size of 15 to 40 mm to reduce m arginal discrepancies and produce an acceptable surface roughness. T h is type of diam ond b u r is used to contour the facial surface of the restoration, b u t w ithout the luster of the enam el surface. Therefore, polishing m aterials m ust be used after d iam ond b u r fin ish in g to add the desirable reflective surface w ith o u t flattening the surface of the resin. H achiya and o thers19 com pared various finishing agents in relation to the discolor­

F ig 3 ■ T h e c o n to u r s trip h as been a p p lie d ,

by an opaquer and subsequently ligh t cured. T he

a tta ch m e n t; the enam el has been etched for 60

meniscus of material at the strip interface has

seconds, rinsed, and dried.

been removed before curing.

produces an extremely bitter taste to the patient. T h e finished an d final veneer should have m argins undetectable to floss or an explorer. T h e surface should em ulate the enam el reflectivity, an d the veneer should have the depth of color m im ick in g the natural teeth.

Report of case A 25-year-old m ale w ith a discolored m ax­ illary left central incisor was exam ined. T h e p atien t had received a blow to the m outh 10 years earlier. T h e tooth tested vital w ith an electrical an d ice test w ith no sign of periapical pathosis on the radio­ graph. T he tooth was correctly aligned

The surface should emulate the enamel reflectivity, and the veneer should have the depth of color mimicking the natural teeth.

atio n of com posite m aterials. T hey found th a t com posite resins finished w ith S ili­ cone P oints, Sof-Lex Discs, and emery papers used w ith a w ater coolant h ad the least discoloration. An enam el luster a p ­ p e a ra n c e c a n be c re a te d u s in g th e m edium , fine, an d superfine grits of the Sof-Lex Discs in order, w ith slow speed. Sof-Lex Discs are best used on a w et sur­ face for a slow er polish and less heat on the surface of the com posite resin because overheating the resin may cause prem a­ ture discoloration. F in ish in g on a wet surface also contains the inevitable dust. F in ish in g dust should be avoided as it 452 m JADA, Vol. 115, September 1987

Fig 4 ■ B onding resin has been applied, followed

e x p o sin g the enam el to the level of the gingival

w ith the adjacent teeth b u t the discol­ oration (a low -value purple) extended to the crest of the gingival tissue (Fig 1). T h e p atient preferred the conservative a p ­ p ro ac h of p la c in g a veneer in stead of p lacing a porcelain crown. C onsidering the alignm en t of the tooth and the extent of the discoloration, a p rep aratio n ex­ tending from the incisal edge to the crest of the gingival m argin was prepared to remove half of the enamel thickness (Fig 2). A b u lle t-n o se d d ia m o n d b u r, th e 799.MF3 /xm finishing diam ond, was used to p re p a re the en am el, w ith o u t a n e s­ thesia. T h e tooth was isolated w ith cotton

rolls an d a co n to u r strip isolated the an terio r to o th surface, ex ten d in g to the gingival attachm ent. T h e co n to u r strip m ust be ap p lied against the enam el su r­ face and stabilized, by p lacin g wedges interproxim ally an d using b o n d in g resin between the gingival tissue an d o n the outside of the facial surface of the strip. Placem ent of the wedges may cause g in ­ gival bleeding, b u t this is n ot significant as the co n to u r strip isolates the tooth, p re v e n tin g tissue ex u d ate an d h e m o r­ rh a g e fro m c o n ta c tin g th e to o th . T o m ain tain adequate isolation d u rin g the c o n d e n s a tio n of th e m ic ro fille d c o m ­ posite resin, the strip m ust be supported. T h e field is rinsed an d dried an d the etchant is ap plied for the required time. After the acid is washed from the surface, the enam el appears a frosty-w hite o p aq u e (Fig 3). A b o n d in g com posite resin was ap p lied to the enam el surface and all the excess resin was removed from the enam el w ith an a ir sy rin g e. T h e o p a q u e m a te ria l m a sk ed th e c o lo r o f th e u n d e r ly in g enam el. T h is was ap p lied w ith an ex­ p lorer as th in as possible and necessary to block the u n derlying color (Fig 4). G en ­ erally, w ith the opaquer, approxim ately 0.3 to 0.5 mm of thickness is required to block lig h t transm ission. Any meniscus of resin between the strip an d the enam el m ust be removed w ith the tine of the explorer before curing. T h e resin should be polym erized an d lig h t cured for 60 seconds. T in ts can recreate the chrom a of the d en tin hu e and the value of the enam el. C om m and U ltrafine Colors were the tints used. For the p a tie n t’s central incisor, a line of décalcification was necessary at the level of the gingival tissue to recreate the décalcification seen on the adjacent teeth. T h is was sim ulated by u sin g a w hite tint.

CLINICAL

T E C H N I Q U E S

re c o rd in g th e d ifferen t layers of co lo r used in their sequence of placem ent. ----------------------- J f i O A ----------------------I n f o r m a tio n a b o u t th e m a n u f a c tu r e r s o f th e pro d u cts m entioned in this article m ay be available from the au th o rs. N either the a u th o rs n o r the A m er­ ican D ental A ssociation has any com m ercial interests in the products m entioned.

* » &

Dr. L arson is associate professor, a n d Dr. P h a ir is assistan t professor, d e partm ent of operative dentistry, U niversity of M innesota School of D entistry, 8-450 M oos H e alth Sciences T ow er, 515 D elaw are St, SE, M inneapolis, 55455. Address requests for re p rin ts to Dr. Larson. Fig 5 ■ A n excess of S ilu x “ L ” shade has been

F ig 7 ■ T h e com pleted veneer on the m axillary

ap p lie d to th e entire facial surface a n d cured.

left central in ciso r 1 week after co m p letio n . T h e s lig h t change in color is caused by the so rp tio n of w ater com pared w ith Figure 6.

Fig 6 ■ T h e com pleted veneer on the m axillary

F ig 8 ■ T h e com pleted veneer o n the m axillary

left central incisor a t the co m p letio n of the p ro ­

left c entral incisor 30 m o n th s after p lacem ent.

cedure. N otice the s im u la tio n of cervical décal­ cification sim ila r to th a t seen o n the m axillary lateral incisors.

After lig h t c u rin g the w hite tin t, a pin k tin t was added to increase the orange chrom a in the gingival third of the crown. P ink, used sparingly and placed over the yellow b ackground of the op aq u e m ate­ rial, slightly increases the orange chrom a. Yellow tint was placed in the m iddle third to increase the yellow chrom a an d create the effect of fluorescence in certain lig h t­ in g conditions. Blue tin t was used at the in cisal edge to create the illu sio n of translucency. All these tints were then lig h t cured. T h e m icrofilled com posite resin used in this case was Silux shade “ L .” T h is shade of com posite resin m ost closely re­ sembled the color of the incisal third of the m axillary rig h t central incisor. As this shade did not provide an adequate range of chrom a, tints were used to im prove the c h ro m a m a tc h a n d re c re a te d e n tin a l color. T h e m aterial w as pressure c o n ­ densed ag ain st the m atrix strip to prevent th e in c lu s io n o f a ir b u b b le s a t th e m argins and to increase the adhesion of the resin to the tooth (Fig 5). T h e resin was polym erized sequentially in 20-sec­ ond increm ents over the surface of the m aterial for 80 seconds. T h e excess b u lk of th e m ic ro fille d

com posite resin was removed, u sin g the 135.MF3 |um fin ish in g diam o n d bur. No. 3 burs were used w ith air and w ater cool­ a n t to provide the final details, an d subtle labial anatom y such as developm ental de­ pressions. P o lish in g was acco m p lish ed on a wet surface, using the Sof-Lex Discs at slow speeds. T h e m edium g rit was used first, follow ed by the fine an d superfine grits. Figure 6 shows the appearance of the finished veneer on the day of place­ m ent. Figure 7 shows the veneer 1 week after placem ent. T h e gingival ad ap tatio n to the com pleted veneer is satisfactory. T h e color of the veneer also appears less bright. T h is loss of brightness, alth o u g h slight, is noticeable and occurs because th e m ic ro fille d c o m p o s ite re s in w ill absorb m oisture, w hich affects the per­ ception of the color. F igure 8 shows the veneer 30 m onths after placement.

Summary T h is technique creates a direct bonded m icrofilled com posite resin veneer that replicates the com plex color d istrib u tio n an d surface texture of the n atu ra l tooth structure. D u plicatin g the com plexity of natu ral tooth color can be repeated by

1. B uonocore, M .G. A sim ple m e th o d of increasing the adhesion of acrylic fillin g m aterials to enam el surfaces. J D ent Res 34:849-853, 1955. 2. B ow en, R. P ro p ertie s of a silic a-re in fo rc e d polym er for dental restorations. JAD A 66(l):57-64, 1963. 3. P fortm iller, N. T h e e v aluation of an o p a q u ed system w ith ultrav io let lig h t polym erized com posite resin veneers for tetracycline an d o th e r stained teeth. T hesis, N orthw estern U niversity, 1974. 4. Cooley, R .O . D ilem m a of the discolored tooth due to tetracycline staining. In G o ldm an, H .M ., and others, eds. C u rre n t therapy in dentistry, vol. 5. St. L ouis, C. V. Mosby Co, 1974, p p 587-593. 5. F aunce, F.R ., a n d Meyers, D .R. L a m in a te veneer resto ratio n of p erm a n e n t incisors. JADA 93(4):790792, 1976. 6. C ouncil o n D ental M aterials, Instrum ents, an d E q u ip m en t. S tatus re p o rt o n enam el b o n d in g of com posite, preform ed lam in ate, a n d laboratory fa b ri­ cated resin veneers. JA D A 109(5):762-764, 1984. 7. C a la m ia , J .R . E tch e d p o rc e la in veneers: the cu rre n t state of the art. Q uintessence In t 16(1 ):5-12, 1985. 8. G oldstein, R.E., an d L ancaster, J.S. Survey of p a tie n t attitu d es tow ard current esthetic procedures. J P rosthet D ent 52(6):775-780, 1984. 9. C hristensen, G .T . V eneering of teeth. D ent C lin N orth A m 29(2):373-391, 1985. 10. J o rd a n , R .E.; Suzuki, M.; a n d G w in n e tt, A.J. C o n s e r v a tiv e a p p l i c a t i o n o f a c i d e tc h r e s in techniques. D ent C lin N o rth Am 25(2):307-345, 1981. 11. L arson, T .D . T ech n iq u es for achieving realistic c o lo r d is trib u tio n in large c o m p o site resto ratio n s. JADA 112(5):669-672, 1986. 12. M iyagaw a, Y., an d Pow ers, J.M . P rediction of c olor of an esthetic restorative m aterial. J D ent Res 62(5):581-584, 1983. 13. R oulet, J.F.; H irt, T .; an d Lutz, F. Surface roughness an d m a rg in a l behaviour of experim ental a n d com m ercial com posites: a n in vitro study. J O ral R ehabil 11:499-509, 1984. 14. Belvedere, P.C., a n d L am bert, D.L. A polyester m a trix system for a p e riodontally sound, acid-etched bonded veneer. N orthw est D ent 63(3): 14-16, 1984. 15. M ow ery, A.S.; K lockow ski, R .J.; a n d D avis, E .L . S im u lta n e o u s versus in d e p e n d e n t p o ly m e ri­ zation of a b o n d in g ag en t a n d com posite resin. O per D ent ll(2):69-73, 1986. 16. M iranda, F.J.; D uncanson, M .G., Jr.; and D ilts, W .W . I n te r f a c ia l b o n d in g s tr e n g th s o f p a ir e d com posite systems. J Prosthet D ent 51(l):29-32, 1984. 17. Boyer, D.B.; C han, K.C.; and R einhardt, J.W . B u ild -u p an d re p a ir of light-cured com posites: bond strength. J D ent Res 63(10):1241-1244, 1984. 18. R oulet, J.F.; H irt, T .; an d Lutz, F. Surface roughness a n d m arginal behaviour of experim ental a n d com m ercial com posites: a n in vitro study. J O ral R ehabil 11:499-509, 1984. 19. H achiya, Y., and others. R elatio n of finish to d isco lo ra tio n of com posite resins. J P rosthet D ent 52(6):811-814, 1984.

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