T h e e ffe c ts on p u lp s o f a p o ly ca rh o xy la te ce m e n t a n d a z in c p h o sp h a te c em en t a lo n e a n d o v e r a p ro tectiv e lin e r w e re tested in a study o f inlays. T h e p u lp a l re s p o n s e to th ree cavity p rep a ra tio n c le a n e rs was d eterm in ed . T eeth tre a te d with z in c o x id e a n d e u g e n o l w ere u s e d as controls; u n trea ted teeth w ere also u se d f o r com parison. R esults w ere c h e c k e d a fter 4 8 ho u rs a n d a fte r 4 5 days.

Pulpal response in rhesus monkeys to cementation agents and cleaners W ilm er B. E am es, DDS Kitsie H en d rix, BA H. C h arles M ohler, DDS, A tlanta

r\

u , „

V j l i n i c i a n s h a v e r e a d c o n f lic tin g r e p o r ts th a t z in c p h o s p h a t e 1 a n d p o ly c a r h o x y la te c e m e n t2 p r o d u c e v a r io u s le v e ls o f p a i n a n d in f la m m a to r y r e s p o n s e s in p u lp s . In o n e o f o u r e a r lie r , u n p u b li s h e d s tu d ie s o n p r i ­ m a te s , te s ts w e r e c o n d u c te d as a b a s e lin e to d e te r ­ m in e p u l p a l r e s p o n s e to z in c p h o s p h a te c e m e n t th a t w a s m ix e d to lu tin g c o n s is te n c y a n d a p p li e d w i t h ­ o u t f o rc e to c a v itie s . A s th e r e w a s n o h y d r a u lic fo rc e , a s th e r e is in c a s tin g c e m e n ta tio n , th e r e s p o n s e w a s m ild a fte r 4 8 h o u r s , c o n tr a r y to th e e m p ir ic a l b e lie f t h a t th in m ix e s o f z in c p h o s p h a te c e m e n t a r e i r r it a t­ in g b e c a u s e o f its e x tr e m e ly lo w p H . A fte r 4 5 d a y s , t h e p u lp a l r e s p o n s e w a s s till m ild . It w a s a ls o b e e n r e p o r te d 3 th a t th e r e a re n o d if f e r ­ e n c e s b e tw e e n z i n c p h o s p h a te a n d p o ly c a r h o x y la te c e m e n ts in th e c o m b in e d d a ta o f 4 8 - h o u r a n d 4 5 -d a y s tu d ie s o f p u lp s . In t h e s a m e s tu d y , le a d p lu g s w e r e u s e d to s im u la te in la y s t h a t w e r e f a b r ic a te d b e fo re th e c a v ity p r e p a r a tio n s w e r e m a d e a n d th a t w e r e a d ju s t e d to f it t h e p r e p a r a tio n s . T h is p r o c e d u r e c o u ld n o t b e c o n s id e r e d c lin ic a l, a n d w o u ld n o t, in fa c t, p r o d u c e th e h y d r a u lic fo rc e th a t h a s o fte n b e e n d e s c r ib e d a s a c h a r a c te r is ti c p h e n o m e n o n th a t o c ­

40 ■ JADA, Vol. 98, January 1979

cu rs during cem entation of p recisio n castin gs. T he pu rp ose of this study w as to exam in e the pulpal responses to cem en tation agents w hen h y­ d rau lic force is used to insert p recision inlays and to exam in e the response of the pulp to certain cavity cleaners.

M a t e r ia ls a n d m e th o d s In the study, pulpal responses to F le c k ’s* luting zinc phosphate cem en t used alone and over a protective lin er (H y d roxy lin et) and to D u relo n i (a polycarb oxylate cem ent) w ere exam in ed. Also con sid ered w as the h yd rau lic force p rodu ced during the seating of p recision inlays. Pulpal respon ses w ere check ed after 4 8 hours and after 4 5 days. Th e results w ere com p ared w ith zinc oxid e and eugenol (ZOE) co n ­ trols and w ith u n treated teeth. U sing a sim ilar tech n iq u e, pulps w ere exam in ed for inflam m ation 4 8 hours and 4 5 days after use of three cav ity preparation clean ers, C avilax,}: w ater, and p oly acry lic acid (Durelon liquid). C avilax is com p osed of 5 0 % m ethyl-ethyl ketone and 5 0 % ethylaceton e and is used to rem ove residual eugenol

after a tem p orary dressing is rem oved. D urelon liq­ u id is an en am el etch an t and m ay be an effective clean er (Dr. Robert Purrm an n , w ritten co m m u n ica ­ tion , A pril 1 9 7 5 ). The inflam m ation in the pulps w as co m p ared w ith th at in un treated pulps and in pu lp s treated w ith ZO E, w h ich w ere controls. In both the studies on the inlays and on the cle a n ­ ers, tw o ad u lt rhesu s m onkeys w ere the exp eri­ m ental an im als. T hese m onkeys w ere given 0 .2 to 0 .3 5 m l d iazep am (Valium ) and 0.7 to 1.3 ml ketam ine (K etaject) in tram u scu larly and then w ere an esth etized w ith 2 .0 to 2 .5 m m sodium p en to ­ barbital given in tram u scu larly both initially and during th e p roced u re. In the study on inlays, tw o m ale m onkeys, each 8 to 9 years old and w eighing 9 .5 5 kg for the 4 8 -h o u r study and 7 .7 0 kg for the 4 5 -d a y stu d y, w ere u sed. In the study on clean ers, tw o fem ale m onkeys, 10 to 12 years old and w eig h ­ ing 5.5 kg (48-h o u r) and 5.1 kg (45-d ay ), w ere used. C loverleaf-shaped Class V preparations, de­ signed to key the inlays in the teeth, w ere cu t coron ally to th e gin giva in all but the third m olars, w h ich w ere left u n treated . O val C lass V p rep aration s w ere cu t co ro n ally to the gingiva in all but the third m o­ lars for the study on cleaners. A ll p reparations w ere cu t w ith ligh t, in term ittent strokes using no. 5 56 carbid e burs (a new bur w as used for each quadrant) on a M idw est§ ultrah igh -sp eed h an d p iece set at m axim u m speed at all tim es and using 30 lb air p ressure w ith 15 m l/m in w ater. It has been su ggested th at th ere should be a rem aining dentin (RD) of less than 1.0 m m in pulpal studies on rhesus m onkeys to co rrelate w ith h u m an tooth resp o n se.4 In our investigation , w e m easured the shortest dis­ tan ce betw een the deep est p ortion of the cav ity p re­ p aration and the n earest pulp in line w ith the d enti­ nal tubules, w h ich is better than m easurin g the cu rv ed length of the dentinal tu b u les.5 A problem w ith previous pulpal studies has been in determ in in g the RD as the preparations are c u t.6,7 To determ in e the co rrect depth, three sets of teeth from rh esu s m onkeys of sim ilar age and size w ere ground m esio d istally w ith a carboru n du m w heel. B y record in g the d istance to the pulp from the enam el su rface at the level above the gingiva and subtracting the ideal RD (0.7 m m ) for each tooth, the ideal av erage depth for the cav ity p rep aration w as calcu lated for each tooth. A Foxll p eriodontal probe w as used to ch eck the depth as the p rep arations w ere cut. E ach p rep ara­ tion w as w iped w ith a co tto n pledget, w h ich w as w et w ith sterile saline solution, and dried w ith five squeezes of a bulb syringe. Care w as taken n ot to d essicate the freshly cu t dentinal tubules, w h ich

w ou ld aspirate odontoblasts. M onkeys in both 4 8 -h o u r and 4 5 -d a y stu d ies w ere treated sim ilarly. E ach of three quadrants receiv ed a test m aterial, and the fourth quadrant w as the co n ­ trol.

Study on inlays In the inlay study, Im p re g u m t (a p oly eth er elastom eric im p ression m aterial) im p ression s w ere m ade, and dies w ere poured w ith V e l-M ix ** gyp ­ sum stone. A m algam of sp h erical a llo y ,+ t at a 1:1 alloy/m ercu ry ratio, w as h a n d -con d en sed into the stone die p rep aration and rem oved after 24 hou rs by ch ip p in g aw ay the stone. This p rovid ed p recise and w ell-ad ap ted inlays. During the 2 4 -h o u r interval b e­ tw een cutting the p rep aration and seating the inlay, the prep aration s w ere sealed w ith ZO E. ZO E w as in corp orated into pledgets of co tto n to facilitate re­ m oval. W hen the tem p orary restoration s w ere re ­ m oved , all p rep aration s w ere w ip ed clean w ith sterile saline solution and w ere ag ain air-dried. Som e can in es w ere elim in ated from the study b e­ cau se they h ad been en d od o n tically treated in other exp erim en ts. The rem ain in g n u m ber of sam ples w as adequate for a statistical an aly sis.8 T eeth lost b e­ cau se of exp osu re and h isto lo g ic tech n iq u e w ere elim in ated . The n u m ber of sam ples for each test m aterial is show n in the Table. F le c k ’s zin c phosphate cem en t w as m ix e d for 90 secon d s using a pow der/liquid ratio of 2 gm :m l. This ratio m eets A D A film -th ick ness sp ecification s and is of the co n sisten cy selected by the E m o ry faculty as the optim um co n sisten cy for luting ce m e n t.9 C em ented am algam inlays w ere held for three m in ­ utes in each tooth tested in the right m axillary quad­ rant. In the right m andibular q u adrant, the den tin of each p rep aration w as lined w ith a thin co a t of Hyd roxylin e and w as allow ed to dry for tw o m inutes. Inlays cem en ted w ith zin c p h osp hate w ere p laced as p reviou sly described. D urelon ce m e n t w as m ixed acco rd in g to the m an u factu rer’s d irectio n s for ap ­ p ro xim ately 4 5 secon d s, and inlays w ere seated in the left m andibular quadrant. ZO E, as th e co n trol, w as p laced in preparations of the left m axillary quadrant, and am algam w as laterally con d en sed w ith light force over this base.

Study of cavity cleaners In the study of clean ers, p o ly a cry lic acid w as p laced in p reparations in the left m axillary q u adrant for tw o m inutes, irrigated w ith sterile saline w ater, dried as Eames-others : PULPAL RESPONSE IN RHESUS MONJKEYS ■ 41

Table ■ Materials and responses in 48-hour and 45-day inlay and cleaner studies. Material

No. of samples

ZnPOj ZnPOi and Hydroxyline Durelon Z0E control Untreated

5 6 3 3 4

ZnPOi ZnPOi and Hydroxyline Durelon ZOE control Untreated

5 5 6 6 4

Polyacrylic Cavilax Water ZOE control Untreated

6 7 6 7 4

Polyacrylic Cavilax Water ZOE control Untreated

7 6 7 7 4

RD*

CDt

SR*

48 hr inlay study 1.12 0.00 2.00 0.57 0.00 1.33 0.70 0.00 0.67 1.20 0.00 1.00 0.00 0.00 0.25 45 days inlay study 0.60 0.66 0.00 0.82 1.20 0.00 1.17 0.75 0.00 0.17 1.18 0.67 0.00 0.00 0.25 48 hr cleaner study 0.17 0.63 0.50 0.57 0.77 0.43 0.00 1.00 0.33 1.54 0.50 0.07 0.00 0.00 0.00 45 days cleaner study 0.57 0.00 0.71 0.58 0.00 0.33 0.47 0.00 0.21 0.87 0.00 0.14 0.00 0.00 0.00

drs

1.00 1.33 0.00 0.67 0.00 0.80 1.00 0.67 0.50 0.50 0.00 0.21 0.33 0.00 0.00 0.57 0.33 0.14 0.00 0.00

*RD—Remaining dentin. |CD—Cellular displacement. |SR—Superficial response. »DR—Deep response.

before, and veneered w ith a p lastic m ix of am algam , w h ich is inert and is suitable as a con trol m aterial w hen p laced w ithout trau m a.10 In the p rep aration s of the left m an dibular quadrant, C avilax w as applied w ith sm all co tto n pledgets, allow ed to dry for two m in utes, and veneered w ith am algam . Sterile saline solution w as u sed to w ash the p rep aration s in the righ t m andibular quadrant; they w ere air-dried as before and restored w ith am algam . The controlq u adrant (right m axillary) w as the sam e as d e­ scribed in the study of inlays. A ll am algam veneers w ere ligh tly carved to the cavosu rface m argin and left un polish ed. T eeth w ere extracted after 4 8 hours and after 4 5 d ays, representing short-term and long-term pulpal reaction s, respectiv ely . It is im p ortan t th at the e x ­ tractio n s be done quickly and as atrau m atically to the pulp as possible. The m onkeys w ere killed. W ithin five m inutes after death, the com p lete m axilla and m andible w ere extracted , using the m ethod of S tan ley .11 The root ap ices w ere rem oved w ith a S tr y k e rii orthop edic saw ; a new blade w as used for each m onkey. The ap ices w ere ch eck ed to ensure that th e pulp tissues w ere not plu gged w ith d ebris12; they w ere then im m ersed im m ediately into a F orm alin solution. W hole m andibles and m axillas w ere fixed in this solution on a shaker table for five to seven days. A fter d écalcificatio n , the teeth w ere sep arated , u sing a B ard-P ark er§§ knife, p laced in ind ivid u al p lastic cassettes, and cod ed . The teeth w ere d ecalcified for 14 days, using the shaker table w ith a d aily ch an g e of a solution co m p o sed of 50% form ic acid and 50% sodium citrate. 42 ■ JADA, Vol. 98, January 1979

The teeth w ere em bedded in paraffin using an A utotechnicon,1lf set in b lock s, cod ed , section ed on a m icrotom e in 7-fx. thickn esses, stained w ith h em atoxy lin and eosin, co v ered , and studied. The criteria for judging pulp al response w ere based on the scale used by Sw erdlow and Stanley4,13,14 (Fig 1). B lind read in g s of th ree zones w ere exam in ed for ch an g es, each graded on a 0 to 3 scale. C ellular d isp lacem en t (CD) w as judged on the n um ber of odontoblasts asp irated into the dentinal tubules. Superficial respon se (SR) w as exam in ed in the odontoblastic layer, the cell-free zone, or the zone of W eil, and the cell-rich zone w as ch eck ed for the num ber of inflam m atory leukocytes. Deep re­ sponse (DR) w as exam in ed in the zone m edial to the cell-rich zone. The t test w as used to co m p are differences be­ tw een the test m aterials and the con trols.

R e s u lt s T h e average RD for the study of inlays w as 0.91 m m ; it w as 0 .7 2 m m for the study of clean ers (Table). The CD, SR, and DR w ere all less than 1 for all test m aterials in the study of clean ers, for both the 4 8 h ou r and 4 5 -day studies (Table). In the study of inlays, z in c p h osp hate cem ent, after 4 8 hours, p ro d u ced a h igh degree of superficial response of 2 .0 , w hereas D urelon, zin c phosphate over H yd roxylin e, and the con trols h ad m ild su p er­ ficial respon ses of 0 .6 7 , 1 .3 3 , and 1 .0 , respectively, as seen in the Table. A ll deep respon ses w ere m ild and w ere 1 .33 or less. In the 4 5 -d a y sam ples, all

Fig 1 ■ A, representative Cavilax-treated sample (48 hours) showing degree 1 superficial response, degree 1 deep response, and degree 3 cellular displacement. B, representative zinc phosphate-treated sample (45 days) showing degree 2 superficial response, degree 3 deep response, and degree 0 cellular displacement. C, representative sample treated with zinc phosphate cement and Hydroxyline (48 hour) showing degree 3 superficial response, degree 2 deep response, and degree 0 cellular displacement. D, representative Durelon-treated sample (48 hours) showing degree 1 to 2 superficial response, degree 1 to 2 deep response, and degree 0 cellular response.

s u p e r f ic ia l a n d d e e p r e s p o n s e s w e r e m ild a n d w e r e a s s e s s e d a s 1 .2 o r le s s . In b o th s tu d ie s , u n tr e a te d te e th h a d le s s s u p e r f i­ c ia l a n d d e e p in f la m m a tio n t h a n th e c o n tr o ls o r te s te d te e th (F ig 2 , 3). M o re s e c o n d a r y d e n t i n w a s s e e n a f te r 4 5 d a y s in th e s tu d y o f in la y s th a n in th e s tu d y o f c le a n e r s . O n e a b s c e s s e a c h w a s s e e n in a to o th tr e a t e d w ith u n l i n e d z i n c p h o s p h a t e c e m e n t ( 4 8 - h o u r s tu d y ) a n d in a to o th tr e a t e d w ith z in c p h o s p h a t e c e m e n t w it h H y d r o x y lin e ( 4 8 - h o u r s tu d y ) . S ta tis tic a l a n a ly s is , u s in g a t te s t m o d if ie d to c o m p a r e to 0 , s h o w e d a s ig n if ic a n t d if fe re n c e b e ­ tw e e n th e te e th tr e a t e d w ith z in c p h o s p h a t e a f te r 4 8 h o u r s a n d te e th tr e a t e d w i t h D u r e lo n a f te r 4 8 h o u r s . P u lp s in t e e th tr e a t e d w i t h D u r e lo n w e r e le s s i n ­ f la m e d .

D is c u s s io n

R e s u lts o f th e s tu d ie s , s e e n in th e T a b le , in d ic a te th a t th e r e is a d if f e r e n c e in th e in f la m m a to r y r e ­ s p o n s e s a f te r 4 8 h o u r s b e tw e e n z in c p h o s p h a te a n d D u r e lo n c e m e n ts . I n itia lly , D u r e lo n is le s s in ju r io u s to th e p u l p t h a n z in c p h o s p h a te c e m e n t. T h e d if fe r ­ e n c e m a y b e d u e to th e r a p id p e n e tr a tio n o f p h o s ­ p h o r ic a c id in to th e tu b u le s f ro m th e h y d r a u lic f o rc e d u r in g c e m e n ta tio n , a s p h o s p h o r ic a c id is a n in o r ­ g a n ic a c id o f s m a ll m o le c u la r w e ig h t. D u r e lo n liq ­ u id ( p o ly a c r y lic a c id ) h a s a la r g e r m o le c u la r s tr u c ­ tu r e a n d m a y n o t p e n e tr a te a s r e a d ily ; its a b ility to c o m p le x w ith p r o te in s r e s u lts in a lim ita tio n o f d if ­ f u s io n th r o u g h th e d e n ti n a l t u b u l e s .15 T h is p o s s ib il­ ity is r e in f o r c e d b y th e r e d u c e d a c u te in f la m m a tio n s e e n w ith z in c p h o s p h a te c e m e n t w h e n H y Eames—others : PULPAL RESPONSE IN RHESUS MONKEYS ■ 43

C e llu la r D is p la c e m e n t ■ S u p e r f ic ia l R e s p o n s e □ Deep R esponse £3 A v e ra g e R e m a in in g D e n tin 0 .7 2 m m

ÍlLL

J~b

LU

•5

re O

co ­

X

o

TJ

LU

‘5

0

-2 —

N

S2

>

o= ©

§ .?

(0

ü

c

2

C h ro n ic - 45 d a y s

A c u te - 4 8 H o u rs

Fig 2 ■ Primate pulpal inflammatory response to cavity cleaning ma­ terials.

C e llu la r D is p la c e m e n t ■ S u p e rfic ia l R e s p o n s e □ Deep Response S A ve ra g e R e m a in in g D e n tin

0.91 m m

-TL £

A cu te - 4 8 Hours

£

O

d roxylin e is used to seal the dentinal tubules. Both cem en t m aterials, h ow ever, yield ed the sam e pulpal respon se in the 4 5 -d a y study. T h e degree of inflam m ation in d u ced in the 4 5 -d a y study is co m p a ­ rable to th at of zin c p h osp hate cem ent w ith H y­ d roxyline lin er and to the ZO E con trol. A ll levels of inflam m atory respon ses, alth ough greater than in u n treated teeth , are w ith in a range th at can be re ­ solved by the rep arative ability of the pulp. T he degree of inflam m ation in d u ced w ith in the first 4 8 hou rs w ith use of zin c p h osphate cem en t w ith ou t an effective liner and u n d er the h yd rau lic force of a castin g cem en tatio n probably cau ses h yp ersen sitivity to the patient. U se of an effective liner, su ch as H ydroxylin e, ap p arently resolves this problem . A ll clean ers studied resulted in m ild pulpal re ­ b

JADA, Vol. 98, January 1979

Su m m ary Th e purp ose of these studies w as to com p are pulpal inflam m atory respon ses in d u ced by cem entation of p recision am algam inlays w ith zin c phosp hate c e ­ m ent, w ith and w ith ou t a H yd roxylin e liner, D ure­ lon cem en t, and ZO E co n trols. H ydraulic force was ind u ced by the inlay insertion procedure. C avilax, w ater, and p o ly acry lic acid w ere co m ­ pared w ith ZO E con trols. B oth studies also used un treated teeth for com p arison . The use of zinc p h osp hate luting cem en t in the 48 -h o u r inlay study w as th e only con d ition p rovok­ ing m od erate to severe respon ses. Z in c phosphate cem en t o ver H yd roxylin e lin er and D urelon cem en t in the stu d y of inlays and C avilax clean er, w ater, and p oly acry lic acid in the stu d y of clean ers show ed m ild respon ses com p arab le to the ZO E con trol in the 4 8 -h o u r and in the 4 5 -d a y periods.

C hronic - 4 5 Days

Fig 3 ■ Primate pulpal inflammatory response to effect of luting ce­ ments under hydraulic force of inlays.

44

sponse in the 4 8 -h o u r and 4 5 -d a y studies. W hen con sid ering m aterials that are m oderate to m ild in their effects on the pulp, it is equally im portant to co n sid er d e siccatio n in d rying, pressure applied on the h an d p iece, interm itten t cu ttin g strokes w ith the h an d p iece in co m p ariso n w ith a con stan t load, am ou nt of w ater used, heat p ro d u ced , and the e x ­ tractio n p ro ced u res. A n y of these con d ition s are p o­ tentially respon sib le for ad verse pulpal responses. Effort w as m ad e in the study to elim inate these v ari­ ables.

*Mizzy, Inc., Clifton Forge, Va. tGeorge Taub Products, Jersey City, NJ 07307. ^Premier Dental Products Co., Norristown, Pa 19401. §Midwest American, Melrose Park, 111 60160. UStar Manufacturing Co., Philadelphia, Pa. **Kerr Manufacturing Co., Romulus, Mich 48174. f+L. D. Caulk Co., Milford, Del 19963. ++Stryker Corporation, Kalamazoo, Mich. §§Bard-Parker, Division of Becton, Dickinson and Co., Rutherford, NJ 07070. WTechnicon Corp., Ardsley, NY.

This study was supported in part by the National Institutes of Health, National Institute of Dental Research, research grant no. 5 RO 1 DE 03504-08, and by the Fifth District Dental Society of Atlanta.

1. Skinner, E.W., and Phillips, R.W. Science of dental materials, ed 6. Philadelphia, W. B. Saunders Co., 1967, p 468. 2. Beardsley, S.H.; Auvenshine, R.C.; and Eames, W.B. Pulpal response to composite resin and polycarboxylate cement. J Dent Res 52(special issue):68, abstract no. 37, Feb 1973. 3. Brannstrom, M., and Nyborg, H. Pulpal reaction to polycarboxylate and zinc phosphate cements used with inlays in deep preparations. JADA 94(2}:308-310, 1977. 4. Sayegh, F.S., and Reed, A.J. Analysis of histologic criteria commonly used in pulp studies. Oral Surg 37(3J:457-462, 1974.

5. Stanley, H.R. Human pulp responses to operative dental procedures. Gainesville, Fla, Shorter Printing Co., 1976. 6. Stanley, H.R.; Conti, A.J.; and Graham, C. Conservation of human research teeth by controlling cavity depth. Oral Surg 39(1):151-156,1975. 7. Edwall, L. Methods of measuring dentinal, pulpal, and periapical reactions to dental materials. Int Dent J 24(2):251-257, 1974. 8. Stanley, H.R. Design for human pulp study. Oral Surg 25(4):633-647, 1968. 9. Eames, W.B., and others. Proportioning and mixing of cements: a comparison of working times. Op Dent 2(3):97-104, 1977. 10. Auvenshine, R.C., and Eames, W.B. Pulpal response of monkeys to modifications of a bisphenol A composite resin and cement. J Dent Res

51(4):1062-1066, 1972. 11. Eames, W.B.; Hendrix, K.; and Cleveland, D. Pulpal protection of liners against zinc phosphate and 50% phosphoric acid: a primate study. Ga J Autumn 1978. 12. Van Hassel, H.J. Physiology of the human dental pulp. Oral Surg 32(1):126-134, 1971. 13. Swerdlow, H., and Stanley, H.R. Response of the human dental pulp to amalgam restorations. Oral Surg 15(4):499-508, 1962. 14. Stanley, H.R. Design for a human pulp study. Oral Surg 25(5):756764,1968. 15. Smith, D.C. Dental cements. Dent Clin North Am 15(1):3-31, 1971.

THE AUTHORS

Dr. Eames is professor of operative dentistry and director of applied dental materials, School of Dentistry, Emory Uni­ versity, Atlanta, Ga 30322. Ms. Hendrix is in the School of Dentistry, class of 1979. Dr. Mohler is in practice in Johnson City, Tenn. Address requests for reprints to Dr. Eames. EAMES

HENDRIX

MOHLER

Eames-others : PULPAL RESPONSE IN RHESUS MONKEYS ■ 45