A R T IC L E S
C
lin ic a l
f o r
e v a lu a t io n
r e s t o r a tio n
o f a
g la s s
o f c e r v ic a l
io n o m
e r
c e m
e n t
e r o s io n
G e r a ld T . C h a rb e n e a u , D D S , M S R a lp h R. B o z e ll I I I , DDS
A glass ionomer cement used to restore cervical abraded or eroded areas can bond the total restoration to the tooth tissue without undercutting or pinning the prepared tooth or relying on geometric design of a cavity preparation.
A
/ 1 new class o f translucent ce m ent described by W ils o n and K e n t1 in 1972 as a glass ionom er is com posed o f an a lu m in o -s ilic a te glass p o w d er and a p o ly a c ry lic acid liq u id . The acronym A S P A * has been used to id e n tify th is m aterial w ith its various p hysica l properties that are p o te n tia lly useful in de n tistry. These properties have been reported by a num b er o f investigators.2' 7 B io lo g ica l responses to the glass io n o m e r m aterials have also been in vestigate d.8,9 P robably the m ost o u tstan ding cla im made fo r these cements is th e ir p o te n tia l fo r b o n d in g n o t o n ly to enamel, but also to d e n tin by means o f p o la r and io n ic a ttraction s2— p h ysio che m ica l adhe sion.4 T h is stu d y assesses the c lin i cal characteristics and usefulness of a n e w ly m arketed glass ionom er ce m ent fo r restoration o f a n a to m ica lly
936 ■JADA, Vol. 98, June 1979
d e fic ie n t contours in the cervical areas o f teeth w ith o u t u n d e rc u ttin g or p in n in g the prepared tooth, or re ly in g on any geom etrical design o f a c a v ity preparation.
Materials and methods T h irty -o n e patients w ere selected; each had a m in im u m o f one too th w ith an eroded ce rvica l area w ith a depth greater than 1 m m (Fig 1, top, 2, top). A ll areas w ere free o f caries. T he cross-sectional fo rm o f the le sion v ie w e d in a sagittal section of the tooth was cla ssifie d according to the angle betw een in c is a l and c e rv i cal w a lls. In fo rm e d consent was ob ta in e d from a ll patients treated. A glass io n o m e r restorative mate ria l that re p o rte d ly adheres to tooth substance was used in the fo rm of prew eighed ca p su le st co n ta in in g
p ro p o rtio n e d p o w d e r and liq u id . These w ere m ixe d fo r 12 seconds on a C aulk V a ri-M ix II am algam ator th a t was set at m edium -2. Before the m a te ria l was inserted, a ll surface stains on teeth w ere re m oved b y cle a n in g w ith Z ircate P rophy Paste w ith use o f a rubber p o lis h in g cup. The area was rinsed and d rie d after p o lis h in g . ASP A Pre lim S o lu tio n t (50% c itric acid) was dispensed in a dappen d ish w here a cotton p ledget was saturated. T h is pledget was agitated lig h tly over the surface o f the c a v ity fo r 30 seconds. A fo rc e fu l spray o f w ater was used to rinse the area th o ro u g h ly d u rin g as p ira tio n . A n A S P A C ervical M a trix ,t a plastic-coated soft m etal, had been p re v io u s ly b u rn ish e d to conform to to o th co n to u r and was used to aid in establishing p re lim in a ry restoration form . The m ix e d restorative m aterial was packed fir m ly in to place and adapted as clo se ly as possible to the m argins o f the ca vity; the ca vity and s u rro u n d in g area w ere kept d ry after they were cleaned by the P re lim So lu tio n . T he m a te ria l was im m e d ia te ly com pressed w ith use o f the m a trix w h ic h was le ft in p o sitio n fo r fiv e m inutes. Is o la tio n from oral
A R T IC L E S
w o u ld n o t become dehydrated. Baseline data w ere recorded after fin is h in g the restoration. M a te ria l re te n tio n (presence, p a rtia l pres ence, o r absence), c o lo r m atch, cavosurface m a rg in a l d isc o lo ra tio n , m a rg in a l in te g rity , ana to m ic fo rm , and caries w ere rated u sin g c rite ria developed b y Cvar and R yge.10 V alues o f roughness w ere deter m in e d w ith use o f an external stan dard suggested b y C handler and o th e rs.11 P hotographs w ere taken at baseline, and at one m o n th , three m onths, and s ix m onths postoperativ e ly . E valuations w ere made by tw o tra in e d exam iners w o rk in g in d e p endently. Disagreem ents were re co n cile d by exam iners observing together and re aching a consensus. P atients w ere questioned at the treatm ent a p p o in tm e n t, at baseline, and at oth e r re ca ll tim es about any sym ptom s o f d is c o m fo rt preoperativ e ly , d u rin g treatm ent, or p ostoperatively.
Results Retention S ix restorations (5.3%) w ere re corded as p a rtia lly m issin g , none was to ta lly m issin g , and 107 (94.7%) were to ta lly present (Fig 1, bottom ; 2, bottom ; 3). T w o o f these six par tia lly m issin g restorations w ere re-
Fig 1 ■Top, preoperative— cervical erosion, m axillary left canine. Bottom, postoperative, six m onths—glass ionom er restoration.
Fig 2 ■Top, preoperative—cervical erosion, m andibular left canine. Bottom, postopera tive, six m onths—glass ionom er restoration.
flu id s d u rin g th is in it ia l setting tim e is required. A fte r the m a trix was re m oved, the restoration was trim m e d p a ra lle l to the cavosurface m argins to avoid liftin g the m ate ria l. A scal p e l blade or sharp scaler was used w ith gentle force. The restoration was then covered w ith A S P A Coat in g ,t a va rn ish th a t in h ib its m o is ture contact w ith the glass ionom er fo r an extended tim e . Local anes thesia was never used fo r any pa tie nt. F in is h in g o f the restora tio n was delayed fo r at least a day; a proce-
dure recom m ended fo r fin is h in g com posite re sin restorations was then used. T h is procedure in c lu d e d the s ilic o n carbide m ounted p o in ts fo r certain b u lk rem oval as in d i cated; the w h ite a lp in e fin is h in g p o in t was used next. S ilic o n carbide disks in hardnesses o f 320, 400, and 6 0 0 t m o u n te d in “ snap-on” or p in h o le m andrels w ere ro u tin e ly used to a lter the co n to u r and fin is h the restoration. A w a te r-so lu b le lu b rica n t§ covered the restoration surface d u rin g the e n tire fin is h in g process so the surface o f the resto ra tio n
fig 3 a postoperative, six m onths—glass ionom er restoration, m andibular second prem olar.
Charbeneau-Bozell : GLASS IONOMER CEMENT ■937
A R T IC L E S
corded at one m o n th , one was re corded at three m onths, and three p a rtia l losses occurred between three and six m onths. R etention was n o t a sp ecific c rite r io n de fin e d b y the D ental H ealth C enter,10 b u t i t has been used in p it and fissure sealant studies to record p a rtia l, com plete, or no loss o f sub stance. W hen the restoration was v i su a lly inspected, i f the restoration was observed as being u n d e r contoured and d isco n tin u o u s w ith anatom ic fo rm , the restoration was g iven the D ental H ealth C enter’s “ bravo ” ra tin g . W hen the restoration was inspected w ith an e xp lo re r fo r m a rg in a l adaptation, i f a crevice was fo u n d in to w h ic h the e xplorer w o u ld penetrate, i t was g ive n the C enter’s “ b ra vo ” ra tin g . These ra t ings fo r anatom ic fo rm or m a rg in a l adaptation, o r both, w ere associated w ith fiv e o f these p a rtia lly m issing restorations. W hen the restoratio n was v is u a lly inspected fo r anatom ic fo rm o r m ar g in a l adaptation, i f the m aterial was d isco n tin u o u s and s u ffic ie n t mate ria l was m issin g so th a t the d e n tin or base was exposed, or i f a crevice was fo u n d th a t exposed the d e n tin or base, the restoration was g ive n the D ental H ealth C enter’s “ C h a rlie ” ra t ing.
C olor N o change in co lo r was seen fo r any o f the restorations at any o f the re ca ll periods. M o st restorations had a m ism a tch in w h a t the D ental H ealth C enter10 term s “ co lo r, shade, and/or translucency betw een the restora tio n s and the adjacent to o th struc tu re ” because o f th e in h e re n t opacity o f the glass ion o m e r m aterial, w h ic h is greater th a n th a t o f silicate ce m ent.
at the interface o f the restoration and to o th tissue.
Caries N o evidence o f caries was seen at the m argins o f any o f the restorations.
R ou gh n ess A t baseline, im m e d ia te ly after fin is h in g , values o f roughness were recorded as 1 (0.4 fo r 112 restora tio n s and 0 (0 jl fo r one restoration. A t six m onths, 71 restorations were rated 1 and the re m a in in g 41 were rated as 2 (0.8 /u,).
/)
/x)
S y m p to m s Several patients reported some fo rm o f preoperative s e n s itiv ity eith e r to tem perature or contact. Each o f these patients had a d im in is h e d se n sitiv ity or to ta l e lim in a tio n o f s e n s itiv ity after placem ent o f the restoration. D u rin g the placem ent procedure, fo u r patients described th is a c tiv ity as a “ ve ry s lig h t” discom fort, a “ tin g lin g ” sensation, “ a sh a llo w b u rn in g ,” or as “ som ewhat sensi tiv e .” No sym ptom s w ere reported b y these fo u r patients im m e d ia te ly after placem ent o r later. N o other pa tie n ts ever reported any fo rm o f sen s itiv ity .
E ffe c t o f fo rm o f c a v ity T he c la s s ific a tio n o f cavities based on the angle form e d betw een the in cisal (occlusal) and ce rvica l w a lls resulted in 11 angles less than 45°, 34 angles m ore than 45° b u t less than 90°, 51 angles m ore than 90° b u t less than 135°, and 17 angles m ore than 135°. The firs t, second, and fo u rth groups each w ere observed to have one “ p a rtia l presence,” whereas the th ird g roup had three.
M a rg in a l d isco lo ra tio n D isco lo ra tio n was e vid e nt on the m a rg in betw een resto ra tio n and to o th tissue in seven o f the 113 res torations (6.2%). One was recorded firs t at one m onth, one firs t at three m onths, and fiv e at s ix m onths. No pen etration o f th is stain was n oticed 938 ■ JA D A , V o l. 98, June 1979
D is c u s s io n There is need to restore the cervical anatom ic deficiencies o f certain teeth to reduce th e rm a l se n sitivitie s; p revent co n tin u e d loss o f to o th sub stance w ith possible in v o lv e m e n t o f p u lp ; assist in m a in ta in in g good oral
hygiene, and perhaps im p ro ve esthetic appearances. Such d e fic ie n cies are m ost often fo u n d on adja cent teeth and m ay present a ch a l lenge to the dentist. T he c la im o f “ adhesion” has been made fo r th is glass ionom er cement fo r restoring ce rvica l anatom ic de ficiencies. T he C o u n c il on D ental M aterials and Devices has offered the o p in io n th a t “ . . . an adhesive m a te ria l fo r use in dental restorative procedures is a substance th a t w o u ld bond to enam el, or d e n tin , or both, w ith o u t re liance on in te rlo c k in g ef fects o r the re te n tio n fo rm o f the prepared ca vity. A n adhesive re storative m a te ria l th u s c o u ld be placed in to o r onto a to o th prepared w ith o u t re te n tio n fo rm and w o u ld rem ain in ta c t and w o u ld effect a seal o f th a t re sto ra tio n in the oral e n v i ro n m e n t.” 12 A c lin ic a l p ro to co l was designed fo r th is s tu d y as an ap p ro p ria te a id in d e te rm in in g th is c la im o f “ adhesion.” The fact th a t none o f the 113 resto rations o f eroded lesions seen at re c a ll p eriods u p to s ix m onths were to ta lly lost c o n firm s previous in v itro fin d in g s 6,7 and confirm s the re sults o f a c lin ic a l stu d y th a t adhesive b o n d in g , as c lin ic a lly d e fin e d ,12 is possible w it h a glass io n o m er ce m ent. P a rtia l loss o f s ix restorations m ay be caused b y certain te ch nica l problem s in c lu d in g in itia l co n to u r ing, fin a l fin is h in g , the fo rm o f the lesion its e lf, c o n ta m in a tio n o f the c o n d itio n e d to o th tissue, and de layed in s e rtio n . Five o f the six pa r tia l losses o f restorations in v o lv e d th in m a rgins w here there was greater chance o f a m echanical d is placem ent d u rin g the in s e rtio n and fin is h in g . A lth o u g h three shades o f m aterial and a shade g u id e are available, m ism atch is fre q u e n t because o f a lack o f translucency. D ental silicate cem ent o p a c ity lies betw een the con trast ra tio (C 0. 70) values o f 0.35 and 0.55. The glass io n o m e r s im ila r to that used in th is s tu d y has been re p o rte d 4 as h a vin g a C 0.70 o f 0.69. C lin ic a lly acceptable esthetic ap pearances are possible w ith a lim ite d num ber o f cases, b u t th is lack o f translucence m ig h t s till be view ed
A R T IC L E S
as a m ajo r obstacle. M a rg in a l sta in in g o f the seven res torations after six m onths was at the surface o n ly, w ith no pene tra tio n o f d is co lo ra tio n along the interface o f the restorative m aterial and to o th tissue. S ta in in g o f surface ir re gu la rities sh o u ld be expected in the m ouths o f ce rta in patients. Con tin u e d absence o f pe netra tio n o f stain in the fu tu re w o u ld be fu rth e r evidence o f b o n d in g o f the cem ent to d e ntin . I t has been sh o w n 13 th a t values of roughness determ ined b y u sin g the external standard, described by C handler and others11 lack re lia b il ity . Interexam iner agreement was on ly about 55%, w h e n three evaluators w ere used, and so the results sh o u ld be considered as perhaps in d ic a tin g o n ly a trend. Thus, the changes in dicated m ay n o t re fle ct a real change. As m ost o f these lesions were sup ra g in g iva l, the effect on the g in g iv a b y d ire c t contact w ith the restoration is n o t o f m u ch concern. The to ta l effect o f th is restorative se quence on the h e a lth o f the g in g iv a l tissues is c u rre n tly being in v e s ti gated. T he rm a l and contact s e n s itiv ity experienced by patients w ere re lie v e d w hen the lesions were re stored. Such a change is expected w h e n the exposed d e n tin surface is covered b y a poor th erm al c o n d u ct in g m ate rial th a t has lo w irrita tio n q u a litie s.8 A s none o f the restora tio ns w ere to ta lly lo st at six m onths, the effect o f c a v ity fo rm on re te n tio n cannot be re lia b ly judged. The fo rm o f the ca vity seems to have little , i f any, in flu e n c e on the p a rtia l loss o f restorative m aterial. A ll cavities were at least 1 m m deep at th e ir deepest p o in t. T h in m argins o f m a te ria l existed w ith m any restora tions, p a rtic u la rly at the extrem e m esial and d is ta l areas. G e n e ra l c lin ic a l o b s e r v a t io n s C onsistent m ixes o f the glass ionom er cem ent w ere n o t e asily at tained w h e n the bulk-packaged p o w d er and liq u id w ere used. T h is
was seen in some early fa ilu re s in re te n tio n in a c lin ic a l tr ia l th a t pre ceded th is study. The p re w eighed capsules and m echanical m ix in g d id seem to ro u tin e ly p roduce a suitable consistency fo r m a n ip u la tin g con venience and fo r a tta in in g b o n d in g . W hen inconsistencies d id e xist after m ix in g , these w ere evident, and the m ix was discarded. The in s e rtio n , m a trix a p p lic a tio n , and in itia l c o n to u rin g o f th is mate ria l do n o t have the appearance o f e xcellent operative technique. A fte r the fin is h in g , how ever, an accept able resto ra tio n can be attained that, at least on a short-term basis, seems to p ro v id e fo r the needs o f the pa tie n t. C o n c lu s io n s a n d s u m m a r y T he fo llo w in g conclusions can be made: A glass io n o m e r cem ent m ix e d in p rew eighed capsules to restore ana to m ic a lly d e fic ie n t ce rvica l contours dem onstrated b o n d in g o f the to ta l restoration to tooth tissue w ith o u t u n d e rc u ttin g o r p in n in g the to o th or re ly in g on geom etric design o f a ca v ity pre p a ratio n in a p p ro xim a te ly 95% o f 113 restorations observed p o sto p e ra tive ly fo r s ix m onths. Seven restorations show ed p a rtia l loss o f m aterial. Seven o f the 113 restorations show ed some m a rg in a l d isco lo ra tio n a lth o u g h no stain penetrated the interface o f the too th and restora tio n . F or m ost ce rvica l restorations, the glass io n o m e r cem ent p ro duced a m ism atch in “ color, shade, and/or tra n slu ce n cy” 10 in re la tio n s h ip to the tooth. T he probable reason fo r th is is the o p a city o f the cement. A n acceptable surface o f the glass io n o m e r cem ent restorations can be established at a later fin is h in g ap p o in tm e n t. There is lit tle evidence th a t roughness increased s lig h tly d u rin g the s ix m onths. P atients’ s e n s itiv ity to tem pera tu re and d ire c t ta c tile contact d i m in is h e d o r was e lim in a te d after placem ent o f the restoration.
* Am algam ated Dental Co., London. tC aulk ASPA Caps Batch no. 061077, L. D. Caulk Co., M ilford, Del 19963, ^W aterproof fine, X-fine, XX-fine, E. C. Moore Co., Dearborn, M ich 48126. §K-Y Lubricating Jelly, Johnson & Johnson, New Brunswick, NJ 08903. Dr. Charbeneau is a professor and chairm an, and Dr. Bozell is a clinical instructor in opera tive dentistry, departm ent of operative den tistry, U niversity of M ichigan, A nn Arbor. A d dress requests for reprints to Dr. Charbeneau, D epartm ent of Operative Dentistry, School of Dentistry, U niversity of M ichigan, A nn Arbor, 48109. 1. W ilson, A.D., and Kent, B.E. A new trans lucent cem ent for dentistry. The glass ionom er cem ent. Br Dent J 132:133-135, 1972. 2. Kent, B.E.; Lewis, B.G.; and W ilson, A.D. The properties of a glass ionom er cem ent. Br Dent J 135:322-326, 1973. 3. A ustralian Dental Standards Laboratory. Dental M aterials. Glass ionom er cem ent. Cur rent notes no. 54. Aust Dent J 21(2):180, 1976. 4. McLean, J.W., and W ilson, A.D. The clin ical developm ent of the glass-ionom er ce m ents. Form ulations and properties. A ust Dent J 22(l):31-36, 1977. 5. Crisp, S., and others. Properties of im proved glass-ionom er cem ent form ulations. J Dent 3(3):125-130, 1975. 6 . M aldonado, A.; Swartz, M.L.; and P hil lips, R.W. A n in vitro study of certain prop erties of a new glass ionom er cem ent. JADA 96(5]:785-791, 1978. 7. Prodger, T.E., and Sym onds, M. ASPA adhesion study. Br Dent J 143{8):266-270, 1977. 8 . Dahl, B.L., and Tronstad, L. Biological tests on a n experim ental glass ionom er (silicopolyacrylate) cem ent. J Oral Rehabil 3(l):19-24, 1976. 9. Grieco, J.A. Pulpal response in dogs to a glass ionom er cem ent restorative m aterial (ASPA) in lined and unlined cavities, thesis. Boston U niversity School of G raduate Den tistry, 1977. 10. Cvar, J.G., and Ryge, G. Criteria for the clinical evaluation of dental restorative m ate rials. San Francisco, US Dept of Health, Educa tion, and W elfare, Bureau of H ealth M anpower Education, Division of Dental Health, Dental Health Center, 1973. 11. Chandler, H.H., and others. Clinical evaluation of a radiopaque com posite restora tive m aterial after three and a half years. J Dent Res 52:1128-1137, 1973. 12. Council on Dental M aterials and De vices. Council statem ent claim s related to “adhesive” restorative m aterials. JADA 88(2}:393-394, 1974. 13. Charbeneau, G.T.; Brandau, H.E.; and Bozell, R.R. A com parative clinical evaluation at two years of glaze m aterials w ith conven tional finishing for com posite resin. J M ich Dent Assoc 60(6):357-363, 1978.
Charbeneau-Bozell : G L A S S IO N O M ER C E M E N T ■ 939
C
lin ic a l
f o r
e v a lu a t io n
r e s t o r a tio n
o f a
g la s s
o f c e r v ic a l
io n o m
e r
c e m
e n t
e r o s io n
G e r a ld T . C h a rb e n e a u , D D S , M S R a lp h R. B o z e ll I I I , DDS
A glass ionomer cement used to restore cervical abraded or eroded areas can bond the total restoration to the tooth tissue without undercutting or pinning the prepared tooth or relying on geometric design of a cavity preparation.
A
/ 1 new class o f translucent ce m ent described by W ils o n and K e n t1 in 1972 as a glass ionom er is com posed o f an a lu m in o -s ilic a te glass p o w d er and a p o ly a c ry lic acid liq u id . The acronym A S P A * has been used to id e n tify th is m aterial w ith its various p hysica l properties that are p o te n tia lly useful in de n tistry. These properties have been reported by a num b er o f investigators.2' 7 B io lo g ica l responses to the glass io n o m e r m aterials have also been in vestigate d.8,9 P robably the m ost o u tstan ding cla im made fo r these cements is th e ir p o te n tia l fo r b o n d in g n o t o n ly to enamel, but also to d e n tin by means o f p o la r and io n ic a ttraction s2— p h ysio che m ica l adhe sion.4 T h is stu d y assesses the c lin i cal characteristics and usefulness of a n e w ly m arketed glass ionom er ce m ent fo r restoration o f a n a to m ica lly
936 ■JADA, Vol. 98, June 1979
d e fic ie n t contours in the cervical areas o f teeth w ith o u t u n d e rc u ttin g or p in n in g the prepared tooth, or re ly in g on any geom etrical design o f a c a v ity preparation.
Materials and methods T h irty -o n e patients w ere selected; each had a m in im u m o f one too th w ith an eroded ce rvica l area w ith a depth greater than 1 m m (Fig 1, top, 2, top). A ll areas w ere free o f caries. T he cross-sectional fo rm o f the le sion v ie w e d in a sagittal section of the tooth was cla ssifie d according to the angle betw een in c is a l and c e rv i cal w a lls. In fo rm e d consent was ob ta in e d from a ll patients treated. A glass io n o m e r restorative mate ria l that re p o rte d ly adheres to tooth substance was used in the fo rm of prew eighed ca p su le st co n ta in in g
p ro p o rtio n e d p o w d e r and liq u id . These w ere m ixe d fo r 12 seconds on a C aulk V a ri-M ix II am algam ator th a t was set at m edium -2. Before the m a te ria l was inserted, a ll surface stains on teeth w ere re m oved b y cle a n in g w ith Z ircate P rophy Paste w ith use o f a rubber p o lis h in g cup. The area was rinsed and d rie d after p o lis h in g . ASP A Pre lim S o lu tio n t (50% c itric acid) was dispensed in a dappen d ish w here a cotton p ledget was saturated. T h is pledget was agitated lig h tly over the surface o f the c a v ity fo r 30 seconds. A fo rc e fu l spray o f w ater was used to rinse the area th o ro u g h ly d u rin g as p ira tio n . A n A S P A C ervical M a trix ,t a plastic-coated soft m etal, had been p re v io u s ly b u rn ish e d to conform to to o th co n to u r and was used to aid in establishing p re lim in a ry restoration form . The m ix e d restorative m aterial was packed fir m ly in to place and adapted as clo se ly as possible to the m argins o f the ca vity; the ca vity and s u rro u n d in g area w ere kept d ry after they were cleaned by the P re lim So lu tio n . T he m a te ria l was im m e d ia te ly com pressed w ith use o f the m a trix w h ic h was le ft in p o sitio n fo r fiv e m inutes. Is o la tio n from oral
A R T IC L E S
w o u ld n o t become dehydrated. Baseline data w ere recorded after fin is h in g the restoration. M a te ria l re te n tio n (presence, p a rtia l pres ence, o r absence), c o lo r m atch, cavosurface m a rg in a l d isc o lo ra tio n , m a rg in a l in te g rity , ana to m ic fo rm , and caries w ere rated u sin g c rite ria developed b y Cvar and R yge.10 V alues o f roughness w ere deter m in e d w ith use o f an external stan dard suggested b y C handler and o th e rs.11 P hotographs w ere taken at baseline, and at one m o n th , three m onths, and s ix m onths postoperativ e ly . E valuations w ere made by tw o tra in e d exam iners w o rk in g in d e p endently. Disagreem ents were re co n cile d by exam iners observing together and re aching a consensus. P atients w ere questioned at the treatm ent a p p o in tm e n t, at baseline, and at oth e r re ca ll tim es about any sym ptom s o f d is c o m fo rt preoperativ e ly , d u rin g treatm ent, or p ostoperatively.
Results Retention S ix restorations (5.3%) w ere re corded as p a rtia lly m issin g , none was to ta lly m issin g , and 107 (94.7%) were to ta lly present (Fig 1, bottom ; 2, bottom ; 3). T w o o f these six par tia lly m issin g restorations w ere re-
Fig 1 ■Top, preoperative— cervical erosion, m axillary left canine. Bottom, postoperative, six m onths—glass ionom er restoration.
Fig 2 ■Top, preoperative—cervical erosion, m andibular left canine. Bottom, postopera tive, six m onths—glass ionom er restoration.
flu id s d u rin g th is in it ia l setting tim e is required. A fte r the m a trix was re m oved, the restoration was trim m e d p a ra lle l to the cavosurface m argins to avoid liftin g the m ate ria l. A scal p e l blade or sharp scaler was used w ith gentle force. The restoration was then covered w ith A S P A Coat in g ,t a va rn ish th a t in h ib its m o is ture contact w ith the glass ionom er fo r an extended tim e . Local anes thesia was never used fo r any pa tie nt. F in is h in g o f the restora tio n was delayed fo r at least a day; a proce-
dure recom m ended fo r fin is h in g com posite re sin restorations was then used. T h is procedure in c lu d e d the s ilic o n carbide m ounted p o in ts fo r certain b u lk rem oval as in d i cated; the w h ite a lp in e fin is h in g p o in t was used next. S ilic o n carbide disks in hardnesses o f 320, 400, and 6 0 0 t m o u n te d in “ snap-on” or p in h o le m andrels w ere ro u tin e ly used to a lter the co n to u r and fin is h the restoration. A w a te r-so lu b le lu b rica n t§ covered the restoration surface d u rin g the e n tire fin is h in g process so the surface o f the resto ra tio n
fig 3 a postoperative, six m onths—glass ionom er restoration, m andibular second prem olar.
Charbeneau-Bozell : GLASS IONOMER CEMENT ■937
A R T IC L E S
corded at one m o n th , one was re corded at three m onths, and three p a rtia l losses occurred between three and six m onths. R etention was n o t a sp ecific c rite r io n de fin e d b y the D ental H ealth C enter,10 b u t i t has been used in p it and fissure sealant studies to record p a rtia l, com plete, or no loss o f sub stance. W hen the restoration was v i su a lly inspected, i f the restoration was observed as being u n d e r contoured and d isco n tin u o u s w ith anatom ic fo rm , the restoration was g iven the D ental H ealth C enter’s “ bravo ” ra tin g . W hen the restoration was inspected w ith an e xp lo re r fo r m a rg in a l adaptation, i f a crevice was fo u n d in to w h ic h the e xplorer w o u ld penetrate, i t was g ive n the C enter’s “ b ra vo ” ra tin g . These ra t ings fo r anatom ic fo rm or m a rg in a l adaptation, o r both, w ere associated w ith fiv e o f these p a rtia lly m issing restorations. W hen the restoratio n was v is u a lly inspected fo r anatom ic fo rm o r m ar g in a l adaptation, i f the m aterial was d isco n tin u o u s and s u ffic ie n t mate ria l was m issin g so th a t the d e n tin or base was exposed, or i f a crevice was fo u n d th a t exposed the d e n tin or base, the restoration was g ive n the D ental H ealth C enter’s “ C h a rlie ” ra t ing.
C olor N o change in co lo r was seen fo r any o f the restorations at any o f the re ca ll periods. M o st restorations had a m ism a tch in w h a t the D ental H ealth C enter10 term s “ co lo r, shade, and/or translucency betw een the restora tio n s and the adjacent to o th struc tu re ” because o f th e in h e re n t opacity o f the glass ion o m e r m aterial, w h ic h is greater th a n th a t o f silicate ce m ent.
at the interface o f the restoration and to o th tissue.
Caries N o evidence o f caries was seen at the m argins o f any o f the restorations.
R ou gh n ess A t baseline, im m e d ia te ly after fin is h in g , values o f roughness were recorded as 1 (0.4 fo r 112 restora tio n s and 0 (0 jl fo r one restoration. A t six m onths, 71 restorations were rated 1 and the re m a in in g 41 were rated as 2 (0.8 /u,).
/)
/x)
S y m p to m s Several patients reported some fo rm o f preoperative s e n s itiv ity eith e r to tem perature or contact. Each o f these patients had a d im in is h e d se n sitiv ity or to ta l e lim in a tio n o f s e n s itiv ity after placem ent o f the restoration. D u rin g the placem ent procedure, fo u r patients described th is a c tiv ity as a “ ve ry s lig h t” discom fort, a “ tin g lin g ” sensation, “ a sh a llo w b u rn in g ,” or as “ som ewhat sensi tiv e .” No sym ptom s w ere reported b y these fo u r patients im m e d ia te ly after placem ent o r later. N o other pa tie n ts ever reported any fo rm o f sen s itiv ity .
E ffe c t o f fo rm o f c a v ity T he c la s s ific a tio n o f cavities based on the angle form e d betw een the in cisal (occlusal) and ce rvica l w a lls resulted in 11 angles less than 45°, 34 angles m ore than 45° b u t less than 90°, 51 angles m ore than 90° b u t less than 135°, and 17 angles m ore than 135°. The firs t, second, and fo u rth groups each w ere observed to have one “ p a rtia l presence,” whereas the th ird g roup had three.
M a rg in a l d isco lo ra tio n D isco lo ra tio n was e vid e nt on the m a rg in betw een resto ra tio n and to o th tissue in seven o f the 113 res torations (6.2%). One was recorded firs t at one m onth, one firs t at three m onths, and fiv e at s ix m onths. No pen etration o f th is stain was n oticed 938 ■ JA D A , V o l. 98, June 1979
D is c u s s io n There is need to restore the cervical anatom ic deficiencies o f certain teeth to reduce th e rm a l se n sitivitie s; p revent co n tin u e d loss o f to o th sub stance w ith possible in v o lv e m e n t o f p u lp ; assist in m a in ta in in g good oral
hygiene, and perhaps im p ro ve esthetic appearances. Such d e fic ie n cies are m ost often fo u n d on adja cent teeth and m ay present a ch a l lenge to the dentist. T he c la im o f “ adhesion” has been made fo r th is glass ionom er cement fo r restoring ce rvica l anatom ic de ficiencies. T he C o u n c il on D ental M aterials and Devices has offered the o p in io n th a t “ . . . an adhesive m a te ria l fo r use in dental restorative procedures is a substance th a t w o u ld bond to enam el, or d e n tin , or both, w ith o u t re liance on in te rlo c k in g ef fects o r the re te n tio n fo rm o f the prepared ca vity. A n adhesive re storative m a te ria l th u s c o u ld be placed in to o r onto a to o th prepared w ith o u t re te n tio n fo rm and w o u ld rem ain in ta c t and w o u ld effect a seal o f th a t re sto ra tio n in the oral e n v i ro n m e n t.” 12 A c lin ic a l p ro to co l was designed fo r th is s tu d y as an ap p ro p ria te a id in d e te rm in in g th is c la im o f “ adhesion.” The fact th a t none o f the 113 resto rations o f eroded lesions seen at re c a ll p eriods u p to s ix m onths were to ta lly lost c o n firm s previous in v itro fin d in g s 6,7 and confirm s the re sults o f a c lin ic a l stu d y th a t adhesive b o n d in g , as c lin ic a lly d e fin e d ,12 is possible w it h a glass io n o m er ce m ent. P a rtia l loss o f s ix restorations m ay be caused b y certain te ch nica l problem s in c lu d in g in itia l co n to u r ing, fin a l fin is h in g , the fo rm o f the lesion its e lf, c o n ta m in a tio n o f the c o n d itio n e d to o th tissue, and de layed in s e rtio n . Five o f the six pa r tia l losses o f restorations in v o lv e d th in m a rgins w here there was greater chance o f a m echanical d is placem ent d u rin g the in s e rtio n and fin is h in g . A lth o u g h three shades o f m aterial and a shade g u id e are available, m ism atch is fre q u e n t because o f a lack o f translucency. D ental silicate cem ent o p a c ity lies betw een the con trast ra tio (C 0. 70) values o f 0.35 and 0.55. The glass io n o m e r s im ila r to that used in th is s tu d y has been re p o rte d 4 as h a vin g a C 0.70 o f 0.69. C lin ic a lly acceptable esthetic ap pearances are possible w ith a lim ite d num ber o f cases, b u t th is lack o f translucence m ig h t s till be view ed
A R T IC L E S
as a m ajo r obstacle. M a rg in a l sta in in g o f the seven res torations after six m onths was at the surface o n ly, w ith no pene tra tio n o f d is co lo ra tio n along the interface o f the restorative m aterial and to o th tissue. S ta in in g o f surface ir re gu la rities sh o u ld be expected in the m ouths o f ce rta in patients. Con tin u e d absence o f pe netra tio n o f stain in the fu tu re w o u ld be fu rth e r evidence o f b o n d in g o f the cem ent to d e ntin . I t has been sh o w n 13 th a t values of roughness determ ined b y u sin g the external standard, described by C handler and others11 lack re lia b il ity . Interexam iner agreement was on ly about 55%, w h e n three evaluators w ere used, and so the results sh o u ld be considered as perhaps in d ic a tin g o n ly a trend. Thus, the changes in dicated m ay n o t re fle ct a real change. As m ost o f these lesions were sup ra g in g iva l, the effect on the g in g iv a b y d ire c t contact w ith the restoration is n o t o f m u ch concern. The to ta l effect o f th is restorative se quence on the h e a lth o f the g in g iv a l tissues is c u rre n tly being in v e s ti gated. T he rm a l and contact s e n s itiv ity experienced by patients w ere re lie v e d w hen the lesions were re stored. Such a change is expected w h e n the exposed d e n tin surface is covered b y a poor th erm al c o n d u ct in g m ate rial th a t has lo w irrita tio n q u a litie s.8 A s none o f the restora tio ns w ere to ta lly lo st at six m onths, the effect o f c a v ity fo rm on re te n tio n cannot be re lia b ly judged. The fo rm o f the ca vity seems to have little , i f any, in flu e n c e on the p a rtia l loss o f restorative m aterial. A ll cavities were at least 1 m m deep at th e ir deepest p o in t. T h in m argins o f m a te ria l existed w ith m any restora tions, p a rtic u la rly at the extrem e m esial and d is ta l areas. G e n e ra l c lin ic a l o b s e r v a t io n s C onsistent m ixes o f the glass ionom er cem ent w ere n o t e asily at tained w h e n the bulk-packaged p o w d er and liq u id w ere used. T h is
was seen in some early fa ilu re s in re te n tio n in a c lin ic a l tr ia l th a t pre ceded th is study. The p re w eighed capsules and m echanical m ix in g d id seem to ro u tin e ly p roduce a suitable consistency fo r m a n ip u la tin g con venience and fo r a tta in in g b o n d in g . W hen inconsistencies d id e xist after m ix in g , these w ere evident, and the m ix was discarded. The in s e rtio n , m a trix a p p lic a tio n , and in itia l c o n to u rin g o f th is mate ria l do n o t have the appearance o f e xcellent operative technique. A fte r the fin is h in g , how ever, an accept able resto ra tio n can be attained that, at least on a short-term basis, seems to p ro v id e fo r the needs o f the pa tie n t. C o n c lu s io n s a n d s u m m a r y T he fo llo w in g conclusions can be made: A glass io n o m e r cem ent m ix e d in p rew eighed capsules to restore ana to m ic a lly d e fic ie n t ce rvica l contours dem onstrated b o n d in g o f the to ta l restoration to tooth tissue w ith o u t u n d e rc u ttin g o r p in n in g the to o th or re ly in g on geom etric design o f a ca v ity pre p a ratio n in a p p ro xim a te ly 95% o f 113 restorations observed p o sto p e ra tive ly fo r s ix m onths. Seven restorations show ed p a rtia l loss o f m aterial. Seven o f the 113 restorations show ed some m a rg in a l d isco lo ra tio n a lth o u g h no stain penetrated the interface o f the too th and restora tio n . F or m ost ce rvica l restorations, the glass io n o m e r cem ent p ro duced a m ism atch in “ color, shade, and/or tra n slu ce n cy” 10 in re la tio n s h ip to the tooth. T he probable reason fo r th is is the o p a city o f the cement. A n acceptable surface o f the glass io n o m e r cem ent restorations can be established at a later fin is h in g ap p o in tm e n t. There is lit tle evidence th a t roughness increased s lig h tly d u rin g the s ix m onths. P atients’ s e n s itiv ity to tem pera tu re and d ire c t ta c tile contact d i m in is h e d o r was e lim in a te d after placem ent o f the restoration.
* Am algam ated Dental Co., London. tC aulk ASPA Caps Batch no. 061077, L. D. Caulk Co., M ilford, Del 19963, ^W aterproof fine, X-fine, XX-fine, E. C. Moore Co., Dearborn, M ich 48126. §K-Y Lubricating Jelly, Johnson & Johnson, New Brunswick, NJ 08903. Dr. Charbeneau is a professor and chairm an, and Dr. Bozell is a clinical instructor in opera tive dentistry, departm ent of operative den tistry, U niversity of M ichigan, A nn Arbor. A d dress requests for reprints to Dr. Charbeneau, D epartm ent of Operative Dentistry, School of Dentistry, U niversity of M ichigan, A nn Arbor, 48109. 1. W ilson, A.D., and Kent, B.E. A new trans lucent cem ent for dentistry. The glass ionom er cem ent. Br Dent J 132:133-135, 1972. 2. Kent, B.E.; Lewis, B.G.; and W ilson, A.D. The properties of a glass ionom er cem ent. Br Dent J 135:322-326, 1973. 3. A ustralian Dental Standards Laboratory. Dental M aterials. Glass ionom er cem ent. Cur rent notes no. 54. Aust Dent J 21(2):180, 1976. 4. McLean, J.W., and W ilson, A.D. The clin ical developm ent of the glass-ionom er ce m ents. Form ulations and properties. A ust Dent J 22(l):31-36, 1977. 5. Crisp, S., and others. Properties of im proved glass-ionom er cem ent form ulations. J Dent 3(3):125-130, 1975. 6 . M aldonado, A.; Swartz, M.L.; and P hil lips, R.W. A n in vitro study of certain prop erties of a new glass ionom er cem ent. JADA 96(5]:785-791, 1978. 7. Prodger, T.E., and Sym onds, M. ASPA adhesion study. Br Dent J 143{8):266-270, 1977. 8 . Dahl, B.L., and Tronstad, L. Biological tests on a n experim ental glass ionom er (silicopolyacrylate) cem ent. J Oral Rehabil 3(l):19-24, 1976. 9. Grieco, J.A. Pulpal response in dogs to a glass ionom er cem ent restorative m aterial (ASPA) in lined and unlined cavities, thesis. Boston U niversity School of G raduate Den tistry, 1977. 10. Cvar, J.G., and Ryge, G. Criteria for the clinical evaluation of dental restorative m ate rials. San Francisco, US Dept of Health, Educa tion, and W elfare, Bureau of H ealth M anpower Education, Division of Dental Health, Dental Health Center, 1973. 11. Chandler, H.H., and others. Clinical evaluation of a radiopaque com posite restora tive m aterial after three and a half years. J Dent Res 52:1128-1137, 1973. 12. Council on Dental M aterials and De vices. Council statem ent claim s related to “adhesive” restorative m aterials. JADA 88(2}:393-394, 1974. 13. Charbeneau, G.T.; Brandau, H.E.; and Bozell, R.R. A com parative clinical evaluation at two years of glaze m aterials w ith conven tional finishing for com posite resin. J M ich Dent Assoc 60(6):357-363, 1978.
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