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Management of Pulp Exposure in the Mixed Dentition
THE J O U R N A L of the
AMERICAN DENTAL ASSOCIATION V ol. 30
F E B R U A R Y 1, 1943
N o. 3
MANAGEMENT OF PULP EXPOSURE IN THE MIXED DENTITION* By K
en n eth
A. E
a s l ic k .
A .M ., D .D . S ., A n n A rbor, M ich .
W O recent reports in d icate th a t of the spaces created by prem ature loss o f the deciduous m olars, from 61 to 36s p er cent of the first deciduous m olar spaces and from 401 to 6a2 per cent of the second deciduous m olar spaces close to such a degree that m alo c clusion m ay develop. T h e frequent sequelae to the early loss o f deciduous m olars— extrusion o f unopposed molars, lingual d riftin g o f incisors, closure of the vertical ja w dim ension (Fig. 1), m alalinem ent or im paction o f bicuspids and loss o f m asticatory fu n ction — bestir the children’s dentist to d evelop a simple, econom ical and safe technic for handling exposed v ital pulps in the deciduous den tition. Sim ilarly, a study b y S alzm ann3 in d i cates that a general disturbance of occlu sion developed in the you n g perm anent dentition o f a group o f 500 N ew Y o rk
T
Read before the Section on Children’s Dentistry at the Seventy-Eighth Annual Mid winter Meeting of the Chicago Dental So ciety, February 24, 1942. *Associate Professor of operative dentistry, University of Michigan, School of Dentistry.
Jour. A.D.A., Vol. 30, February 1, 1943
children from 5 to 19 years o f age w ho h ad lost from one to fo u r perm anent m o lars. C o n tra ry to the conclusion reached by a n um ber of dentists, the second m olars o f these children did not m igrate forw ard to occu py the spaces th at had been m ade by the extraction o f the first molars. Y ears o f clin ical observation by children’s dentists has tau gh t that, as a rule, im m ed iately upon th e rem oval o f a youn g first perm anent m olar, the child patien t starts on the w ay tow ard an early cripp led perm anent dentition. (Fig. 2.) T h is observation has led to the de velopm ent of experim ental technics to preserve y o u n g teeth even w hen a cavity reaches the p u lp cham ber b efore the roots h ave com pleted calcification. (Fig. 3.) Perhaps experim ental procedures m ay be condoned if they preserve youn g perm anent m olars and you n g fractu red incisors until root form ation progresses to com pletion. T h e ob ject o f this paper, a t any rate, is to present some o f the technics w hich appear to h a ve a w ide application to those teeth o f the m ixed dentition that had exposed v ital pulps. 179
i8 o
a
T h e J o u r n a l o f t h e A m e r ic a n D e n t a l A s s o c ia t io n
d e v it a l iz a t io n
-p u l p o t o m y t e c h n ic
f o r d e c id u o u s t e e t h
A com bined devitalization and pulpotom y techn ic has been em ployed since 1930 in the C h ild ren ’s C lin ic o f the U n i versity o f M ich iga n , School o f D entistry, to treat the v ita l exposed pulps of d e ciduous teeth. C onsiderable effort has been devoted to the preparation of a paste th a t w ould devitalize prom p tly w ith the m inim um of pain and danger to p a rap ica l tissues. T h e form u la o f the paraform ald ehyd e paste best ad ap ted to this task is as fo llo w s :
P araform aldehyde Procaine base V aselin Powdered asbestos C arm ine
1.00 0.30 1.25 0.50 0.02
W hen it is determ ined that caries has
if a toothach e ensues and to rep eat the dose an hou r later if the p ain has not ceased. Y o u n g ’s rule is em ployed to de term ine dosages for youn g children. T h e child is dismissed fo r a tw o-w eek period to give the slow ly a ctin g p ara form aldehyde an op portu n ity to d ev ita l ize com pletely the coronal p ortion o f the pulp. Should the pu lp tissue exh ib it sen sation w hen tested b y an exp lo rer a t the second appointm ent, new paste m a y be sealed in the cavity fo r another w eek. A t the second appointm ent, th e tooth is isolated and sterilized w ith tin cture of m ercresin, and sterile instrum ents are em ployed to operate on it. I f the operator finds it difficult to m ain tain a dry, u n contam inated field, h e m a y p u n ch one hole in a rubber dam and c la m p the tooth to be operated upon. T h e ivory
Fig. 1.— Prem ature loss of m an dibu lar prim ary m olars in bo y aged 8. T h e m an dibu lar perm a n en t incisors w ere b itin g again st the p a lata l mucosa.
penetrated to the pulp, a sedative, such as oil o f cloves or chloretone-eugenol, is applied on cotton fo r a few m om ents at the depth o f the cavity. T h e cavity is d ried w ith cotton and an am ount o f the paste th a t can be taken on the tip of a plastic instrum ent is p laced over the exposed p u lp and is sealed in the c av ity w ith out pressure under a thin m ix o f zinc phosphate cem ent. T h e set cem ent filling is trim m ed out o f occlusion before the p atien t is dismissed. Since som e patients react u n favo ra b ly to the form alin th at is slowly liberated from the devitalizing paste, the child patien t is supplied w ith an envelope th a t contains tw o doses of acetylsalicylic acid. T h e envelope is in scribed w ith directions to take one dose
N o. 2A , rubber-dam clam p has been fou n d suitable fo r the deciduous m olars. U su ally, dryness has been m ain tained successfully in the low er teeth, w ith a m ilder problem o f b eh avior m anagem ent, by the use of tw o N o. 3 cotton rolls, one N o. 2 cotton roll, an old-style, ch ild ’s size cotton roll retainer and a saliva ejector th a t w ill not irritate the m ucous m em brane or take m uch room in a preschool child ’ s m outh. T w o cotton rolls, a N o. 2 below and a N o. 3 above, are placed a lo n g the side and beneath the tongue on the side to be treated. F igures 4 and 5 illustrate a suitable equipm en t an d its use. T h e pu lp cham ber is opened w id e w ith a fissure bar, the pu lp tissue tested w ith
E a s lic k — P u lp E x p o s u re
an explorer (there should b e n o sensa tion or bleeding) an d a large round b u r revolved about the p u lp cham ber floor to am putate the desensitized tissue a t the level o f the openings to the root canals. (F ig. 6.) T h e p u lp ch am b er is cleaned w ith sterile cotton pellets and a paste is sealed perm anently over the stum ps of p u lp tissue that rem ain in the root canals. T h e form ulas fo r the prep aration o f the p ow d er and liquid are :
Powder Zinc oxide T hym ol iodide W hite rosin (pow dered) P araform aldehyde
181
a plu n ger to push the paste to place. T h e w arm burnisher serves to burnish the gu tta-p erch a over the paste. A cem ent base can be p laced a t once, a m atrix adjusted and a silver am algam filling inserted im m ediately. Som e effort has been m ade to evalu ate this pulpotom y tech n ic from the stan d point o f safety to health, since its relative ease o f perform ance and the fa c t th at it
14.8 2.0 3.0 0.3
F ig. 2.— A n exploratory roentgenogram of 14-year-old bo y show ing effect on occlusion of early loss of perm anent teeth.
Fig. 4.— Equipm ent suggested to secure dryness for operations on m an dibular prim ary molars during deciduous or m ixed dentition.
Fig. 3.— R o ot ends o f fou r you n g perm anent te e th ; show ing effect o f early exposure of pulps.
G lycerite of Iodine L iquid Iodine (crystals) 0.3 G lycerin 15.0 To prepare, heat ingredients on a hot w ater bath un til solution occurs.
Fig. 5.— Equipm en t adjusted to isolate de ciduous m andibular molars.
O n e drop of the liqu id is m ixed w ith sufficient pow d er to secure a paste that has the consistency o f w h ipp ed cream . E nough of the paste is carried to the pu lp cham ber to cover the floor. Since the paste is oily and hen ce d ifficult to place, a piece o f baseplate gu tta-p erch a the size o f the p u lp cham b er m a y be taken on a smooth hot burnisher and used as
takes little of the operator’s tim e m ake it a practical technic in p rivate p ra c tice. A large n um ber o f treated teeth have been observed fo r v a ryin g periods of tim e b y periodic roentgenographic check-ups. A series o f check-up roen tgen ogram s o f one treated m olar can be studied in F igure 7. T h e m olar shown was
T h e J o u r n a l o f t h e A m e r ic a n D e n t a l A s s o c ia t io n
m aintained for a total period o f six years. Its com plete root resorption u p to the gu tta-p erch a base (right side) w ill be noted in F igu re 8, a ph otograph taken im m ediately after exfoliation . T w en ty -fo u r patients w ith tw entyseven treated teeth h ave returned to the children ’s clin ic fo r a check-up during the first semester o f the present school year. F ro m the roen tgenographic and clin ical appearan ce alone, nineteen of these treated teeth, w h ich have been ob-
Fig. 6.— C oron al pulp rem oved revolutions of large round bur.
by
few
dentition. C ultures taken w ith a sterile cotton pellet by w ip in g ou t the pu lp cham ber floor im m ediately a fte r the pu lp am putation have disclosed th e presence of bacteria in some teeth and the absence of bacteria in oth er teeth. S im ilar find ings h ave been noted in recalled patients w hen the pu lp cham bers h a ve been re opened and cultured. Som etim es a posi tive or a negative cu ltu re has been ob tained w hen the initial cond ition was the reverse bacteriologically. T h e or ganism s most frequently recovered w ere Streptococcus viridans and an h em olytic streptococci. T h e only positive correla tion discernible betw een the presence of bacteria and the clinical ap p eara n ce in the sm all group of teeth studied b ac teriologically has been positive cultures from the teeth ju d ged to be definite fa il ures clinically. I t m ay be of interest at this po in t to
F ig. 7.— Series of check-up roentgenogram s of deciduous m olar th at was retain ed a fter treat m ent b y p ulpotom y, for six years. T h e roentgenogram s (left to rig h t), above, w ere taken M arch 6, 1931 ; A p ril 2, 1932 ; below , F ebru ary 3, 1934, and F ebru ary 1, 1936.
served fo r periods varyin g from seven m onths to five years, can be ju d g ed as successful— a 70 p e r cen t success fo r the periods o f observation. T h e only true criterion o f success in any treated p ulp -in vo lved tooth is the absence o f h arm ful bacteria. Such an evaluation is difficult in patients o f p re school age or the age o f early m ixed
note roentgenographic evalu ation o f the success o f the pulpotom y technics em ployed in the dental clin ic o f the E ast m an Institute of Stockholm .4 A n average o f m ore than three roen tgenograp hic e x am inations w ere m ade o f 1,055 pulpotom ized deciduous m olars in the m ouths o f 480 children. T h e treatm ents w ere perform ed by fifty-one d ifferen t op era
E a s l ic k — P u l p E x p o s u r e
tors, w ho used arsenic trioxide in m ost o f the teeth as a d evitalizin g agent. S at isfactory results w ere obtained in 57.6 per cent of the teeth studied. a
v it a l
pu lpo tom y
t e c h n ic
fo r
D EC ID U O U S AND Y O U N G PER M AN E N T T E E T H
For approxim ately ten years, exp e rience has been accu m u latin g to show
Fig. 8.— E xfoliated crow n from case shown in Figure 7, Jan uary 7, 1937. A t the right, the pulpal floor of the tooth h ad resorbed u n til it exposed the baseplate gu tta-p erch a that was used to push the pulp-ch am ber paste to place.
Fig. 9.— D eciduous m olar, anesthetized and treated b y v ita l p u lp oto m y technic. T h e case w as follow ed roen tgenographically for four years. T h e roentgenogram s are arran ged chron ologically from le ft to righ t and up per to lower.
the rationality o f the vital pu lp otom y technic for youn g perm anent teeth. T h e choice betw een the v ita l pulpotom y te ch nic or the d evitalization -pulpotom y tech
18 3
nic fo r prim ary teeth appears to rest w ith the operator. B y the use of the v ital technic, the pu lp otom y and entire filling can be com pleted fo r a deciduous tooth, frequently in one appointm ent, if the operator is dexterous in the use o f local anesthesia fo r y o u n g patients. C opiou s hem orrhage into the p u lp cham b er is one of the com plications that som etim es arise w ith the use o f the vital pu lp otom y technic. U sually, such hem orrhage can be m anaged readily by the topical
F ig. 10.— Six-year check-up of perm anent m olar treated b y vital pulpotom y techn ic (roentgenogram s taken chron ologically from left to right and upper to lo w e r). A t twoyear intervals, the filling w as rem oved and the v ita lity of the p u lp stumps determ ined.
Fig. 1 1 .— Secon dary dentin ro of deposited over all three root canals in period of ten m onths, in 2 1 -year-old college student. L e ft, condition previous to pulpotom y. R ig h t, a p pearance at ten-m onth check-up.
application o f adrenalin hydrochloride, 1 :1000, or neosynephrin hydrochloride, 1 per cent. D eep anesthesia is im perative if a m anagem ent problem is to be avoid ed during a pulpotom y on ch ildren ’s vital teeth, deeper anesthesia, in fact, than is required for the extraction o f these teeth.
18 4
T h e J o u r n a l o f t h e A m e r ic a n D e n t a l A s s o c ia t io n
A n in ferior dental b lock anesthesia is used routinely for the low er m olars o f all children, includ ing th e preschool group, the in jection b eing m ade as n ea rly as possible a t the point w here the inferior den tal n erve enters its foram en in the m andible. T h is injection can b e rein forced b y parodontal infiltration into the socket o f each r o o t ; and if a rubber dam clam p is to be p laced , b y a lon g b u ccin a tor nerve block. F o r th e u pp er teeth, sub periosteal infiltration is used both b u cca lly and lingually. Som e slight exp e rience w ith n asopalatine block anes thesia5 seems to in d icate th a t it is the anesthesia o f choice fo r the am putation o f pulps in the fou r m axillary incisors. Anesthesia has appeared to be m ore p ro foun d a fter oil o f cloves or choretone-
T h e p u lp cham ber is w ashed w ith a sterile saline solution and dried w ith sterile cotton pellets. Previously, th e use o f the paste alread y suggested fo r the devitalization technic in the p u lp cham ber, follow ed the vital pulpotom ies. A paste of calciu m hyd roxid e and sterile distilled w ater has been used as the p u lp ch am b er paste, how ever, ever since the reports published by T eu sch er6 an d
F ig. 12.— L e ft lateral incisor in 9-year-old b o y w h ich , alth o ugh knocked loose in a cci dent, regained v ita lity three weeks later.
eugenol has been sealed in the cavity over the exposed pulp fo r at least tw enty-four hours prior to the p u lp am putation. T h e am putation o f the anesthetized pu lp is carried out b y the sam e steps th a t are taken fo r th e am pu tation o f the devitalized p u lp tissue o f deciduous teeth. T h e am putation is m ade a t the level o f the p u lp cham ber floor in m olars and a t h a lf the len gth o f the a vailab le root in anterior teeth. A ru bber dam is em ployed for all perm anent m olars, exposing on ly the m olar to b e treated. Iv o ry clam ps N o. 14 and N o. 5 h a ve proved successful in the retention o f the rubber dam on m olars the clin ical crowns o f w h ich are not entirely erupted.
F ig. 13.— F ractured and abscessed cen tral incisor in bo y aged 6 1 . T h re e bacteriolo gic a lly n egative cultures w ere ob tained , and the root can al was filled to the level o f the v ita l tissue. In a seven-m onth p eriod , the root-end v irtu ally com pleted its form ation. ( L e ft colum n dow nw ard, condition M a rch 3 1, A p ril 8, M a y 13, 1 9 4 1 ; rig h t colum n dow nw ard, condition June 16 and O cto b er 4, 19 4 1, and Jan uary 21, 1942.)
E a s l ic k — P u l p E x p o s u r e
Z a n d e r7 on the rap id calcification of dentin roofs over the vital am putated stum ps o f root-canal tissue a fter treat m ent b y a preparation consisting essen tially o f calciu m hydroxide. F igu re 9 shows a fou r-year check-up o f a vital p ulpotom y perform ed on a second p ri m ary m olar in w h ich the previous paste was used. F igu re 10 shows a six-year check-up o f a m axillary first perm anent m olar that was am putated a t t h e . age o f 11 years. T h ree times d u rin g this sixy ear period, the filling was rem oved and the vitality o f the pu lp stum ps d eter m ined w ith fine, sharp instrum ents. F igu re 11 shows the roentgenogram s of a 2 1 -year-old college student a t the tim e a vital pulpotom y was perform ed on the second m olar and a t th e recall period ten m onths later. C alciu m h yd ro xid e paste w as used in the p u lp cham ber. A t the
185
lateral incisor, w h ich since the accid en t h ad consistently given no reaction to v i tality tests. T h e series o f roentgenographic ch eck ups in F igu re 13 tells the story o f the treatm ent o f an abscessed fractu red in cisor in a b o y years o f age. T h e abscess w as drained by a labial incision through the periosteum . T h e follow in g day, the tooth was opened through the lingu al surface, flushed out w ith a syringeful o f trichlor, and cam phorated param onochlorphenol w as sealed, u nder zinc phosphate cem ent. T h e form u la for the prep aration o f the cam phorated param onochlorphenol fo llo w s :
Gum camphor 14 Param onochlorphenol 6 M ix and perm it to liquefy for fortyeight hours. D u rin g an eight-day period, this treat-
Fig. 14.— Interdental roentgenogram s of deciduous m olar of girl aged 9 I at tim e of pulp cap p in g (left) and seven weeks la te r (rig h t).
tim e o f the second roentgenogram , the filling was rem oved. A carefu l exp lo ra tion w ith fine, sharp instrum ents by two operators failed to detect th e entrance to any of the three root canals, so com pletely had they been calcified near the level o f the p u lp cham ber floor. T h e pulps o f you n g perm anent teeth frequently exhibit rem arkable recu p era tive powers. In a football gam e, th e left deciduous m axillary cuspid o f a 9-yearold boy (Fig. 12) was knocked out. T h e perm anent lateral incisor was shifted laterally the distance o f its ow n diam eter and the central incisor was forced into linguoversion w ith its opponent. T h ree weeks after these teeth w ere realined and w ired to position, vitality retu rned to the
m ent was repeated daily and cultures w ere taken. T h e last three cultures w ere n e g a tiv e ; hence, the root can al w as filled w ith a thick m ix o f paste as fa r as the point a t w h ich sensation was experienced by the patient. T h e paste selected con sisted o f the pow d er and glycerite of iodin th a t h ave been described previously for use in the d evitalized deciduous teeth. Successive roentgenogram s disclosed the continued calcification o f the root end until it was p ractically com plete seven m onths later. Som e attem pt has been m ade to evaluate b acteriologically the v ital p u lp otom y technic. T e n patients w ere re called du rin g the y ear 1940 at an a ver aged elapsed tim e o f one y ear a fter
T h e J o u r n a l o f t h e A m e r ic a n D e n t a l A s s o c ia t io n
treatm ent ; the fillings and paste w ere rem oved, and cultures w ere taken. T w o of the ten teeth gave positive cultures. In both instances, the patients returned because of “ soreness” in the treated teeth. (T h is investigation w as m ade by H enry M . W ilbur, D .D .S ., M .S ., w hile a m em ber of the C h ild ren ’s C lin ic staff. T h e bactériologie exam ination was m ade by M a ry C . C row ley, M .S .P .H ., instructor in den tal bacteriology, School of D e n tistry, U n iversity o f M ich igan .) e x p e r i e n c e w i t h a p u l p -c a p p i n g t e c h n ic
Because o f reports in 19378 and later9
p h ate and sm all am ounts o f calciu m fluoride and m agnesium phosphate, was used as the paste for these experim ents. In the ligh t o f this experience, the staff m em bers of the children’ s clin ic decided to experim ent w ith calcium hyd ro xid e as a pu lp -capp in g agent. A fe w deciduous teeth w ith slight e x posure of the pulps w ere selected in clin ic patients durin g the past y ear to test the p u lp -cap p in g effect o f a paste m ade from a m ixture o f calciu m hydroxide, as the pow der, and a suspension o f p o w dered silver n itrate in approxim ately equal parts of C an a d a balsam an d oil o f cloves, as the liquid. A fte r consider able agitation, the liquid suspension was secured accordin g to the follow in g fo rm u la :
C an ada balsam O il of cloves Silver nitrate (powdered)
F ig. 15.— H istologic section of treated tooth in F igu re 14. ( X i 5 - ) S. D ., band of secondary dentin now covering p u lp at point of exposure.
from the C h ild ren ’s C lin ic of C olu m b ia U niversity, describing successful pulpcap p in g technics fo r deciduous and youn g perm anent teeth, it becam e evid ent that fu rth er study should be m ade to reevalu ate some previously unsuccessful pulpcap p in g technics. In 1941, an E nglish report o f the successful p u lp -capp in g o f v ita l exposed pulps in rath er m ature patients was published.10 C alciu m h y droxide solution m ixed w ith certain salts, such as calcium carbonate, calciu m phos
7.0 7.3 0.7
T h e cavities in each instance w ere sterilized w ith phenol after the rem oval o f the carious d e n tin ; a sm all am ount of the pu lp -capp in g paste w as placed over the exposed pulp, and a tem porary filling was inserted. F igu re 14 shows interdental roen tgeno gram s o f one o f these deciduous teeth, before and after the pu lp cap pin g, in a girl g-|- years of age. T h e tooth was selected fo r the experim ent because it appeared to be rap id ly ap proach in g its norm al exfoliation period. Seven weeks later, the tooth was extracted and a histologic exam ination m ade by D . A . K err, A .B ., D .D .S ., instructor in p a th ology, Schools o f D en tistry and M ed icin e, U n iversity o f M ichigan . F igu re 15 shows a section through the m olar at the point o f exposure. A t this m agnification, a b an d o f secondary dentin can b e noted coverin g the point of exposure. T h is band o f secondary dentin is m ore easily studied in F igu re 16. T h e p u lp beneath this b an d is norm al excep t fo r som e slight irritation im m ediately beneath the silverim pregnated dentin. D eep er in the pu lp
187
E a s l i c ic — P u l p E x p o s u r e
tissue are a few small islets o f youn g bone.
B IB LIO G R A PH Y
SU M M A RY AND CO N CLUSIO NS
1 . C o h e n , J. T . : Selection of Cases for Space M aintainers. N orthw est D en t., 20:75-84, A p ril 1941.
T h ree technics for the m anagem ent of exposed pulps in deciduous and young perm anent teeth have been review ed. C ertain conclusions can be d raw n : 1. R oentgen ographically, the results of paraform ald ehyd e devitalization o f e x posed vital pulps in deciduous teeth and the subsequent treatm ent by a pu lp otom y tech n ic ind icate a relatively h ig h degree o f success, although some refinem ents o f diagnosis and treatm ent are ind icated to elim inate the failures. 2. A m p u tation o f the anesthetized vital exposed pulps in deciduous and youn g perm anent teeth has been accom plished
2. B r a u e r , J. C .: R ep ort of 113 E a rly or Prem ature E xtractions of Prim ary M olars and Inciden ce of ClosurQ of Space. J. D ent, for C h ild ., 8:222-224, 4 th Q u arter, 1941. 3. S a l z m a n n , J. A .: S tu d y of O rthodontic and F acia l C han ges and E ffects on D entition A tten d in g Loss of F irst M olars in F ive H u n dred A dolescents. J .A .D .A ., 25:892-905, June 1938. 4. O s t m a n , B i r g e r , and T h y b e r g , H a r a l d : R oentgenologische K o n tro lle pulpachirurgish behan delter M ilch zähn e. A cta O d on tol. Scandinav., 3:3-32, June 1941. 5. P h i l l i p s , W . H ., and M a x m e n , H . A .: N asopalatine B lock In jection as A id in O p e ra tive Procedures for M a x illa ry Incisors. A m . J. O rthodontics, 27:426-434, A u g u st 1941.
F ig. 16.— F urth er enlargem ent ( X 1 0 0 ) of repaired area in dicated in F igu re 15. S. D ., repair band o f secondary dentin. N orm al p u lp tissue is in dicated at P ; w hile at D , silver im pregnated dentin can be noted.
6. T e u s c h e r , G. W . , and Z a n d e r , H . A .: w ith considerable success. R a p id c a lc i Prelim in ary R ep ort on Pulpotom y. N o rth fication has follow ed the use of calcium west. U niv. D . B ull., 29:4-8, D ecem ber 5, hydroxide as a pulp cham ber paste, and 1938. com pletion o f uncalcified root ends has 7. Z a n d e r , H . A . : R eactio n of P u lp to follow ed the em ploym ent o f the vital C alciu m H ydroxide. /. D . R es., 18 :3 73-379, A u gu st 1939. pulpotom y technic. 3. R ecen t evidence of prom otion of 8. R o s e n s t e i n , S. N . : Studies in C on serva tion o f D eciduous and E a rly Perm anent T eeth . secondary dentin form ation b y a pulp/. D . R es., 16 :2 9 -3 1, F eb ru ary 1937. cap p in g technic in the few instances in 9. R o s e n s t e i n , S. N . : P u lp C a p p in g in w h ich this technic has been utilized in D eciduous T e e th : R ep ort of T e n -Y e a r Study. deciduous teeth w arrants further exp e J .A .D .A ., 2 9 :16 3 2 , Septem ber 1942. rim ental work, includ ing histologic study, 1 0 . D i l l o n , C h a r l e s : Experim ents in Pulp of teeth th at h ave been treated by pulpT h e ra p y b y A p p licatio n of C alciu m . Brit. D . cappin g. ] ., 70:365-368, M a y 15, 1941.
AMERICAN DENTAL ASSOCIATION V ol. 30
F E B R U A R Y 1, 1943
N o. 3
MANAGEMENT OF PULP EXPOSURE IN THE MIXED DENTITION* By K
en n eth
A. E
a s l ic k .
A .M ., D .D . S ., A n n A rbor, M ich .
W O recent reports in d icate th a t of the spaces created by prem ature loss o f the deciduous m olars, from 61 to 36s p er cent of the first deciduous m olar spaces and from 401 to 6a2 per cent of the second deciduous m olar spaces close to such a degree that m alo c clusion m ay develop. T h e frequent sequelae to the early loss o f deciduous m olars— extrusion o f unopposed molars, lingual d riftin g o f incisors, closure of the vertical ja w dim ension (Fig. 1), m alalinem ent or im paction o f bicuspids and loss o f m asticatory fu n ction — bestir the children’s dentist to d evelop a simple, econom ical and safe technic for handling exposed v ital pulps in the deciduous den tition. Sim ilarly, a study b y S alzm ann3 in d i cates that a general disturbance of occlu sion developed in the you n g perm anent dentition o f a group o f 500 N ew Y o rk
T
Read before the Section on Children’s Dentistry at the Seventy-Eighth Annual Mid winter Meeting of the Chicago Dental So ciety, February 24, 1942. *Associate Professor of operative dentistry, University of Michigan, School of Dentistry.
Jour. A.D.A., Vol. 30, February 1, 1943
children from 5 to 19 years o f age w ho h ad lost from one to fo u r perm anent m o lars. C o n tra ry to the conclusion reached by a n um ber of dentists, the second m olars o f these children did not m igrate forw ard to occu py the spaces th at had been m ade by the extraction o f the first molars. Y ears o f clin ical observation by children’s dentists has tau gh t that, as a rule, im m ed iately upon th e rem oval o f a youn g first perm anent m olar, the child patien t starts on the w ay tow ard an early cripp led perm anent dentition. (Fig. 2.) T h is observation has led to the de velopm ent of experim ental technics to preserve y o u n g teeth even w hen a cavity reaches the p u lp cham ber b efore the roots h ave com pleted calcification. (Fig. 3.) Perhaps experim ental procedures m ay be condoned if they preserve youn g perm anent m olars and you n g fractu red incisors until root form ation progresses to com pletion. T h e ob ject o f this paper, a t any rate, is to present some o f the technics w hich appear to h a ve a w ide application to those teeth o f the m ixed dentition that had exposed v ital pulps. 179
i8 o
a
T h e J o u r n a l o f t h e A m e r ic a n D e n t a l A s s o c ia t io n
d e v it a l iz a t io n
-p u l p o t o m y t e c h n ic
f o r d e c id u o u s t e e t h
A com bined devitalization and pulpotom y techn ic has been em ployed since 1930 in the C h ild ren ’s C lin ic o f the U n i versity o f M ich iga n , School o f D entistry, to treat the v ita l exposed pulps of d e ciduous teeth. C onsiderable effort has been devoted to the preparation of a paste th a t w ould devitalize prom p tly w ith the m inim um of pain and danger to p a rap ica l tissues. T h e form u la o f the paraform ald ehyd e paste best ad ap ted to this task is as fo llo w s :
P araform aldehyde Procaine base V aselin Powdered asbestos C arm ine
1.00 0.30 1.25 0.50 0.02
W hen it is determ ined that caries has
if a toothach e ensues and to rep eat the dose an hou r later if the p ain has not ceased. Y o u n g ’s rule is em ployed to de term ine dosages for youn g children. T h e child is dismissed fo r a tw o-w eek period to give the slow ly a ctin g p ara form aldehyde an op portu n ity to d ev ita l ize com pletely the coronal p ortion o f the pulp. Should the pu lp tissue exh ib it sen sation w hen tested b y an exp lo rer a t the second appointm ent, new paste m a y be sealed in the cavity fo r another w eek. A t the second appointm ent, th e tooth is isolated and sterilized w ith tin cture of m ercresin, and sterile instrum ents are em ployed to operate on it. I f the operator finds it difficult to m ain tain a dry, u n contam inated field, h e m a y p u n ch one hole in a rubber dam and c la m p the tooth to be operated upon. T h e ivory
Fig. 1.— Prem ature loss of m an dibu lar prim ary m olars in bo y aged 8. T h e m an dibu lar perm a n en t incisors w ere b itin g again st the p a lata l mucosa.
penetrated to the pulp, a sedative, such as oil o f cloves or chloretone-eugenol, is applied on cotton fo r a few m om ents at the depth o f the cavity. T h e cavity is d ried w ith cotton and an am ount o f the paste th a t can be taken on the tip of a plastic instrum ent is p laced over the exposed p u lp and is sealed in the c av ity w ith out pressure under a thin m ix o f zinc phosphate cem ent. T h e set cem ent filling is trim m ed out o f occlusion before the p atien t is dismissed. Since som e patients react u n favo ra b ly to the form alin th at is slowly liberated from the devitalizing paste, the child patien t is supplied w ith an envelope th a t contains tw o doses of acetylsalicylic acid. T h e envelope is in scribed w ith directions to take one dose
N o. 2A , rubber-dam clam p has been fou n d suitable fo r the deciduous m olars. U su ally, dryness has been m ain tained successfully in the low er teeth, w ith a m ilder problem o f b eh avior m anagem ent, by the use of tw o N o. 3 cotton rolls, one N o. 2 cotton roll, an old-style, ch ild ’s size cotton roll retainer and a saliva ejector th a t w ill not irritate the m ucous m em brane or take m uch room in a preschool child ’ s m outh. T w o cotton rolls, a N o. 2 below and a N o. 3 above, are placed a lo n g the side and beneath the tongue on the side to be treated. F igures 4 and 5 illustrate a suitable equipm en t an d its use. T h e pu lp cham ber is opened w id e w ith a fissure bar, the pu lp tissue tested w ith
E a s lic k — P u lp E x p o s u re
an explorer (there should b e n o sensa tion or bleeding) an d a large round b u r revolved about the p u lp cham ber floor to am putate the desensitized tissue a t the level o f the openings to the root canals. (F ig. 6.) T h e p u lp ch am b er is cleaned w ith sterile cotton pellets and a paste is sealed perm anently over the stum ps of p u lp tissue that rem ain in the root canals. T h e form ulas fo r the prep aration o f the p ow d er and liquid are :
Powder Zinc oxide T hym ol iodide W hite rosin (pow dered) P araform aldehyde
181
a plu n ger to push the paste to place. T h e w arm burnisher serves to burnish the gu tta-p erch a over the paste. A cem ent base can be p laced a t once, a m atrix adjusted and a silver am algam filling inserted im m ediately. Som e effort has been m ade to evalu ate this pulpotom y tech n ic from the stan d point o f safety to health, since its relative ease o f perform ance and the fa c t th at it
14.8 2.0 3.0 0.3
F ig. 2.— A n exploratory roentgenogram of 14-year-old bo y show ing effect on occlusion of early loss of perm anent teeth.
Fig. 4.— Equipm ent suggested to secure dryness for operations on m an dibular prim ary molars during deciduous or m ixed dentition.
Fig. 3.— R o ot ends o f fou r you n g perm anent te e th ; show ing effect o f early exposure of pulps.
G lycerite of Iodine L iquid Iodine (crystals) 0.3 G lycerin 15.0 To prepare, heat ingredients on a hot w ater bath un til solution occurs.
Fig. 5.— Equipm en t adjusted to isolate de ciduous m andibular molars.
O n e drop of the liqu id is m ixed w ith sufficient pow d er to secure a paste that has the consistency o f w h ipp ed cream . E nough of the paste is carried to the pu lp cham ber to cover the floor. Since the paste is oily and hen ce d ifficult to place, a piece o f baseplate gu tta-p erch a the size o f the p u lp cham b er m a y be taken on a smooth hot burnisher and used as
takes little of the operator’s tim e m ake it a practical technic in p rivate p ra c tice. A large n um ber o f treated teeth have been observed fo r v a ryin g periods of tim e b y periodic roentgenographic check-ups. A series o f check-up roen tgen ogram s o f one treated m olar can be studied in F igure 7. T h e m olar shown was
T h e J o u r n a l o f t h e A m e r ic a n D e n t a l A s s o c ia t io n
m aintained for a total period o f six years. Its com plete root resorption u p to the gu tta-p erch a base (right side) w ill be noted in F igu re 8, a ph otograph taken im m ediately after exfoliation . T w en ty -fo u r patients w ith tw entyseven treated teeth h ave returned to the children ’s clin ic fo r a check-up during the first semester o f the present school year. F ro m the roen tgenographic and clin ical appearan ce alone, nineteen of these treated teeth, w h ich have been ob-
Fig. 6.— C oron al pulp rem oved revolutions of large round bur.
by
few
dentition. C ultures taken w ith a sterile cotton pellet by w ip in g ou t the pu lp cham ber floor im m ediately a fte r the pu lp am putation have disclosed th e presence of bacteria in some teeth and the absence of bacteria in oth er teeth. S im ilar find ings h ave been noted in recalled patients w hen the pu lp cham bers h a ve been re opened and cultured. Som etim es a posi tive or a negative cu ltu re has been ob tained w hen the initial cond ition was the reverse bacteriologically. T h e or ganism s most frequently recovered w ere Streptococcus viridans and an h em olytic streptococci. T h e only positive correla tion discernible betw een the presence of bacteria and the clinical ap p eara n ce in the sm all group of teeth studied b ac teriologically has been positive cultures from the teeth ju d ged to be definite fa il ures clinically. I t m ay be of interest at this po in t to
F ig. 7.— Series of check-up roentgenogram s of deciduous m olar th at was retain ed a fter treat m ent b y p ulpotom y, for six years. T h e roentgenogram s (left to rig h t), above, w ere taken M arch 6, 1931 ; A p ril 2, 1932 ; below , F ebru ary 3, 1934, and F ebru ary 1, 1936.
served fo r periods varyin g from seven m onths to five years, can be ju d g ed as successful— a 70 p e r cen t success fo r the periods o f observation. T h e only true criterion o f success in any treated p ulp -in vo lved tooth is the absence o f h arm ful bacteria. Such an evaluation is difficult in patients o f p re school age or the age o f early m ixed
note roentgenographic evalu ation o f the success o f the pulpotom y technics em ployed in the dental clin ic o f the E ast m an Institute of Stockholm .4 A n average o f m ore than three roen tgenograp hic e x am inations w ere m ade o f 1,055 pulpotom ized deciduous m olars in the m ouths o f 480 children. T h e treatm ents w ere perform ed by fifty-one d ifferen t op era
E a s l ic k — P u l p E x p o s u r e
tors, w ho used arsenic trioxide in m ost o f the teeth as a d evitalizin g agent. S at isfactory results w ere obtained in 57.6 per cent of the teeth studied. a
v it a l
pu lpo tom y
t e c h n ic
fo r
D EC ID U O U S AND Y O U N G PER M AN E N T T E E T H
For approxim ately ten years, exp e rience has been accu m u latin g to show
Fig. 8.— E xfoliated crow n from case shown in Figure 7, Jan uary 7, 1937. A t the right, the pulpal floor of the tooth h ad resorbed u n til it exposed the baseplate gu tta-p erch a that was used to push the pulp-ch am ber paste to place.
Fig. 9.— D eciduous m olar, anesthetized and treated b y v ita l p u lp oto m y technic. T h e case w as follow ed roen tgenographically for four years. T h e roentgenogram s are arran ged chron ologically from le ft to righ t and up per to lower.
the rationality o f the vital pu lp otom y technic for youn g perm anent teeth. T h e choice betw een the v ita l pulpotom y te ch nic or the d evitalization -pulpotom y tech
18 3
nic fo r prim ary teeth appears to rest w ith the operator. B y the use of the v ital technic, the pu lp otom y and entire filling can be com pleted fo r a deciduous tooth, frequently in one appointm ent, if the operator is dexterous in the use o f local anesthesia fo r y o u n g patients. C opiou s hem orrhage into the p u lp cham b er is one of the com plications that som etim es arise w ith the use o f the vital pu lp otom y technic. U sually, such hem orrhage can be m anaged readily by the topical
F ig. 10.— Six-year check-up of perm anent m olar treated b y vital pulpotom y techn ic (roentgenogram s taken chron ologically from left to right and upper to lo w e r). A t twoyear intervals, the filling w as rem oved and the v ita lity of the p u lp stumps determ ined.
Fig. 1 1 .— Secon dary dentin ro of deposited over all three root canals in period of ten m onths, in 2 1 -year-old college student. L e ft, condition previous to pulpotom y. R ig h t, a p pearance at ten-m onth check-up.
application o f adrenalin hydrochloride, 1 :1000, or neosynephrin hydrochloride, 1 per cent. D eep anesthesia is im perative if a m anagem ent problem is to be avoid ed during a pulpotom y on ch ildren ’s vital teeth, deeper anesthesia, in fact, than is required for the extraction o f these teeth.
18 4
T h e J o u r n a l o f t h e A m e r ic a n D e n t a l A s s o c ia t io n
A n in ferior dental b lock anesthesia is used routinely for the low er m olars o f all children, includ ing th e preschool group, the in jection b eing m ade as n ea rly as possible a t the point w here the inferior den tal n erve enters its foram en in the m andible. T h is injection can b e rein forced b y parodontal infiltration into the socket o f each r o o t ; and if a rubber dam clam p is to be p laced , b y a lon g b u ccin a tor nerve block. F o r th e u pp er teeth, sub periosteal infiltration is used both b u cca lly and lingually. Som e slight exp e rience w ith n asopalatine block anes thesia5 seems to in d icate th a t it is the anesthesia o f choice fo r the am putation o f pulps in the fou r m axillary incisors. Anesthesia has appeared to be m ore p ro foun d a fter oil o f cloves or choretone-
T h e p u lp cham ber is w ashed w ith a sterile saline solution and dried w ith sterile cotton pellets. Previously, th e use o f the paste alread y suggested fo r the devitalization technic in the p u lp cham ber, follow ed the vital pulpotom ies. A paste of calciu m hyd roxid e and sterile distilled w ater has been used as the p u lp ch am b er paste, how ever, ever since the reports published by T eu sch er6 an d
F ig. 12.— L e ft lateral incisor in 9-year-old b o y w h ich , alth o ugh knocked loose in a cci dent, regained v ita lity three weeks later.
eugenol has been sealed in the cavity over the exposed pulp fo r at least tw enty-four hours prior to the p u lp am putation. T h e am putation o f the anesthetized pu lp is carried out b y the sam e steps th a t are taken fo r th e am pu tation o f the devitalized p u lp tissue o f deciduous teeth. T h e am putation is m ade a t the level o f the p u lp cham ber floor in m olars and a t h a lf the len gth o f the a vailab le root in anterior teeth. A ru bber dam is em ployed for all perm anent m olars, exposing on ly the m olar to b e treated. Iv o ry clam ps N o. 14 and N o. 5 h a ve proved successful in the retention o f the rubber dam on m olars the clin ical crowns o f w h ich are not entirely erupted.
F ig. 13.— F ractured and abscessed cen tral incisor in bo y aged 6 1 . T h re e bacteriolo gic a lly n egative cultures w ere ob tained , and the root can al was filled to the level o f the v ita l tissue. In a seven-m onth p eriod , the root-end v irtu ally com pleted its form ation. ( L e ft colum n dow nw ard, condition M a rch 3 1, A p ril 8, M a y 13, 1 9 4 1 ; rig h t colum n dow nw ard, condition June 16 and O cto b er 4, 19 4 1, and Jan uary 21, 1942.)
E a s l ic k — P u l p E x p o s u r e
Z a n d e r7 on the rap id calcification of dentin roofs over the vital am putated stum ps o f root-canal tissue a fter treat m ent b y a preparation consisting essen tially o f calciu m hydroxide. F igu re 9 shows a fou r-year check-up o f a vital p ulpotom y perform ed on a second p ri m ary m olar in w h ich the previous paste was used. F igu re 10 shows a six-year check-up o f a m axillary first perm anent m olar that was am putated a t t h e . age o f 11 years. T h ree times d u rin g this sixy ear period, the filling was rem oved and the vitality o f the pu lp stum ps d eter m ined w ith fine, sharp instrum ents. F igu re 11 shows the roentgenogram s of a 2 1 -year-old college student a t the tim e a vital pulpotom y was perform ed on the second m olar and a t th e recall period ten m onths later. C alciu m h yd ro xid e paste w as used in the p u lp cham ber. A t the
185
lateral incisor, w h ich since the accid en t h ad consistently given no reaction to v i tality tests. T h e series o f roentgenographic ch eck ups in F igu re 13 tells the story o f the treatm ent o f an abscessed fractu red in cisor in a b o y years o f age. T h e abscess w as drained by a labial incision through the periosteum . T h e follow in g day, the tooth was opened through the lingu al surface, flushed out w ith a syringeful o f trichlor, and cam phorated param onochlorphenol w as sealed, u nder zinc phosphate cem ent. T h e form u la for the prep aration o f the cam phorated param onochlorphenol fo llo w s :
Gum camphor 14 Param onochlorphenol 6 M ix and perm it to liquefy for fortyeight hours. D u rin g an eight-day period, this treat-
Fig. 14.— Interdental roentgenogram s of deciduous m olar of girl aged 9 I at tim e of pulp cap p in g (left) and seven weeks la te r (rig h t).
tim e o f the second roentgenogram , the filling was rem oved. A carefu l exp lo ra tion w ith fine, sharp instrum ents by two operators failed to detect th e entrance to any of the three root canals, so com pletely had they been calcified near the level o f the p u lp cham ber floor. T h e pulps o f you n g perm anent teeth frequently exhibit rem arkable recu p era tive powers. In a football gam e, th e left deciduous m axillary cuspid o f a 9-yearold boy (Fig. 12) was knocked out. T h e perm anent lateral incisor was shifted laterally the distance o f its ow n diam eter and the central incisor was forced into linguoversion w ith its opponent. T h ree weeks after these teeth w ere realined and w ired to position, vitality retu rned to the
m ent was repeated daily and cultures w ere taken. T h e last three cultures w ere n e g a tiv e ; hence, the root can al w as filled w ith a thick m ix o f paste as fa r as the point a t w h ich sensation was experienced by the patient. T h e paste selected con sisted o f the pow d er and glycerite of iodin th a t h ave been described previously for use in the d evitalized deciduous teeth. Successive roentgenogram s disclosed the continued calcification o f the root end until it was p ractically com plete seven m onths later. Som e attem pt has been m ade to evaluate b acteriologically the v ital p u lp otom y technic. T e n patients w ere re called du rin g the y ear 1940 at an a ver aged elapsed tim e o f one y ear a fter
T h e J o u r n a l o f t h e A m e r ic a n D e n t a l A s s o c ia t io n
treatm ent ; the fillings and paste w ere rem oved, and cultures w ere taken. T w o of the ten teeth gave positive cultures. In both instances, the patients returned because of “ soreness” in the treated teeth. (T h is investigation w as m ade by H enry M . W ilbur, D .D .S ., M .S ., w hile a m em ber of the C h ild ren ’s C lin ic staff. T h e bactériologie exam ination was m ade by M a ry C . C row ley, M .S .P .H ., instructor in den tal bacteriology, School of D e n tistry, U n iversity o f M ich igan .) e x p e r i e n c e w i t h a p u l p -c a p p i n g t e c h n ic
Because o f reports in 19378 and later9
p h ate and sm all am ounts o f calciu m fluoride and m agnesium phosphate, was used as the paste for these experim ents. In the ligh t o f this experience, the staff m em bers of the children’ s clin ic decided to experim ent w ith calcium hyd ro xid e as a pu lp -capp in g agent. A fe w deciduous teeth w ith slight e x posure of the pulps w ere selected in clin ic patients durin g the past y ear to test the p u lp -cap p in g effect o f a paste m ade from a m ixture o f calciu m hydroxide, as the pow der, and a suspension o f p o w dered silver n itrate in approxim ately equal parts of C an a d a balsam an d oil o f cloves, as the liquid. A fte r consider able agitation, the liquid suspension was secured accordin g to the follow in g fo rm u la :
C an ada balsam O il of cloves Silver nitrate (powdered)
F ig. 15.— H istologic section of treated tooth in F igu re 14. ( X i 5 - ) S. D ., band of secondary dentin now covering p u lp at point of exposure.
from the C h ild ren ’s C lin ic of C olu m b ia U niversity, describing successful pulpcap p in g technics fo r deciduous and youn g perm anent teeth, it becam e evid ent that fu rth er study should be m ade to reevalu ate some previously unsuccessful pulpcap p in g technics. In 1941, an E nglish report o f the successful p u lp -capp in g o f v ita l exposed pulps in rath er m ature patients was published.10 C alciu m h y droxide solution m ixed w ith certain salts, such as calcium carbonate, calciu m phos
7.0 7.3 0.7
T h e cavities in each instance w ere sterilized w ith phenol after the rem oval o f the carious d e n tin ; a sm all am ount of the pu lp -capp in g paste w as placed over the exposed pulp, and a tem porary filling was inserted. F igu re 14 shows interdental roen tgeno gram s o f one o f these deciduous teeth, before and after the pu lp cap pin g, in a girl g-|- years of age. T h e tooth was selected fo r the experim ent because it appeared to be rap id ly ap proach in g its norm al exfoliation period. Seven weeks later, the tooth was extracted and a histologic exam ination m ade by D . A . K err, A .B ., D .D .S ., instructor in p a th ology, Schools o f D en tistry and M ed icin e, U n iversity o f M ichigan . F igu re 15 shows a section through the m olar at the point o f exposure. A t this m agnification, a b an d o f secondary dentin can b e noted coverin g the point of exposure. T h is band o f secondary dentin is m ore easily studied in F igu re 16. T h e p u lp beneath this b an d is norm al excep t fo r som e slight irritation im m ediately beneath the silverim pregnated dentin. D eep er in the pu lp
187
E a s l i c ic — P u l p E x p o s u r e
tissue are a few small islets o f youn g bone.
B IB LIO G R A PH Y
SU M M A RY AND CO N CLUSIO NS
1 . C o h e n , J. T . : Selection of Cases for Space M aintainers. N orthw est D en t., 20:75-84, A p ril 1941.
T h ree technics for the m anagem ent of exposed pulps in deciduous and young perm anent teeth have been review ed. C ertain conclusions can be d raw n : 1. R oentgen ographically, the results of paraform ald ehyd e devitalization o f e x posed vital pulps in deciduous teeth and the subsequent treatm ent by a pu lp otom y tech n ic ind icate a relatively h ig h degree o f success, although some refinem ents o f diagnosis and treatm ent are ind icated to elim inate the failures. 2. A m p u tation o f the anesthetized vital exposed pulps in deciduous and youn g perm anent teeth has been accom plished
2. B r a u e r , J. C .: R ep ort of 113 E a rly or Prem ature E xtractions of Prim ary M olars and Inciden ce of ClosurQ of Space. J. D ent, for C h ild ., 8:222-224, 4 th Q u arter, 1941. 3. S a l z m a n n , J. A .: S tu d y of O rthodontic and F acia l C han ges and E ffects on D entition A tten d in g Loss of F irst M olars in F ive H u n dred A dolescents. J .A .D .A ., 25:892-905, June 1938. 4. O s t m a n , B i r g e r , and T h y b e r g , H a r a l d : R oentgenologische K o n tro lle pulpachirurgish behan delter M ilch zähn e. A cta O d on tol. Scandinav., 3:3-32, June 1941. 5. P h i l l i p s , W . H ., and M a x m e n , H . A .: N asopalatine B lock In jection as A id in O p e ra tive Procedures for M a x illa ry Incisors. A m . J. O rthodontics, 27:426-434, A u g u st 1941.
F ig. 16.— F urth er enlargem ent ( X 1 0 0 ) of repaired area in dicated in F igu re 15. S. D ., repair band o f secondary dentin. N orm al p u lp tissue is in dicated at P ; w hile at D , silver im pregnated dentin can be noted.
6. T e u s c h e r , G. W . , and Z a n d e r , H . A .: w ith considerable success. R a p id c a lc i Prelim in ary R ep ort on Pulpotom y. N o rth fication has follow ed the use of calcium west. U niv. D . B ull., 29:4-8, D ecem ber 5, hydroxide as a pulp cham ber paste, and 1938. com pletion o f uncalcified root ends has 7. Z a n d e r , H . A . : R eactio n of P u lp to follow ed the em ploym ent o f the vital C alciu m H ydroxide. /. D . R es., 18 :3 73-379, A u gu st 1939. pulpotom y technic. 3. R ecen t evidence of prom otion of 8. R o s e n s t e i n , S. N . : Studies in C on serva tion o f D eciduous and E a rly Perm anent T eeth . secondary dentin form ation b y a pulp/. D . R es., 16 :2 9 -3 1, F eb ru ary 1937. cap p in g technic in the few instances in 9. R o s e n s t e i n , S. N . : P u lp C a p p in g in w h ich this technic has been utilized in D eciduous T e e th : R ep ort of T e n -Y e a r Study. deciduous teeth w arrants further exp e J .A .D .A ., 2 9 :16 3 2 , Septem ber 1942. rim ental work, includ ing histologic study, 1 0 . D i l l o n , C h a r l e s : Experim ents in Pulp of teeth th at h ave been treated by pulpT h e ra p y b y A p p licatio n of C alciu m . Brit. D . cappin g. ] ., 70:365-368, M a y 15, 1941.