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RESEARCH REPORTSClinical

DOI: 10.1177/0022034508330884

Received June 22, 2007; Last revision September 24, 2008;

Accepted December 14, 2008

F. Trachtenberg1*, N.N. Maserejian1,J.A. Soncini2,3, C. Hayes4, andM. Tavares2

1New England Research Institutes, 9 Galen Street, Watertown,

MA 02472, USA; 2 The Forsyth Institute, Clinical Collabora-

tive, Boston, MA, USA; 3 Boston University School of Dental

Medicine, Department of Pediatric Dentistry, Boston, MA,

USA; and 4 Tufts University School of Dental Medicine,

Department of Public Health and Community Service,

Boston, MA, USA; *corresponding author, ftrachtenberg@

neriscience.com

J Dent Res 88(3):276-279, 2009

AbSTRACTCompomer restorations release fluoride to help

prevent future caries. We tested the hypothesis that

compomer is associated with fewer future caries

compared with amalgam. The five-year New

England Childrens Amalgam Trial recruited 534

children aged 6-10 yrs with 2 carious posterior

teeth. Children were randomized to receive com-

pomer or amalgam restorations in primary poste-

rior teeth, placed with a fluoride-releasing bonding

agent. The association between restorative mate-

rial and future caries was assessed by survival

analysis. Average follow-up of restorations (N =

1085 compomer, 954 amalgams) was 2.8 + 1.4 yrs

in 441 children. No significant difference between

materials was found in the rate of new caries on

different surfaces of the same tooth. Incident car-

ies on other teeth appeared slightly more quickly

after placement of compomer restorations (p =

0.007), but the difference was negligible after 5

yrs. Under the conditions of this trial, we found no

preventive benefit to fluoride-releasing compomer

compared with amalgam.

KEY WORDS: compomers; dental amalgam;dental caries; dentition, primary; clinical trial.

Does Fluoride in CompomersPrevent Future Caries in Children?

INTRODUCTION

Compomer dental restorations were developed to combine the mechani-cal and esthetic properties of composites with the fluoride-releasingadvantage of glass-ionomer cements. The fluoride released into the mouth

by compomer is intended to help protect against future caries (Eichmiller and

Marjenhoff, 1998; Burke et al., 2006). It has been shown that compomer does

in fact release fluoride into the mouth (Chung et al., 1998; Grobleret al., 1998;

Ylp and Smales, 1999; Karantakis et al., 2000; Asmussen and Peutzfeldt,

2002; Marczuk-Kolada et al., 2006), which has a preventive effect against

future caries compared with composite materials without fluoride (Chung

et al., 1998; Dionysopoulos et al., 1998; Donly and Grandgenett, 1998; Hicks

et al., 2000; Torii et al., 2001; Attar and Onen, 2002; Gonzalez Ede et al.,

2004; Yaman et al., 2004). Two survey articles (Burke et al., 2006; Wiegand

et al., 2006) concluded that although fluoride-releasing materials, including

compomer, inhibit the formation of caries in vitro, such effects have not yet

been determined in vivo. Additionally, there is very limited literature compar-

ing compomer with amalgam in this regard, despite the continued widespread

use of amalgam for dental restorations.

Although amalgam contains no fluoride to protect against future caries, it

has very different properties compared with compomer/composite, which

may protect against future caries by other means. One prior study (Markset al., 1999) has compared recurrent caries by compomer and amalgam

materials in primary molars using a split-mouth design. After 3 yrs of

follow-up, out of 17 restorations with each material, one restoration of each

type required replacement due to recurrent caries. However, the sample size

of this study was too small for a small to moderate effect to be detected.

Therefore, the relative potential for prevention of future caries for compomer

and amalgam has not yet been well-established.

The purpose of this analysis is to compare the incidence of new caries after

children are randomized to receive compomer or amalgam restorations, with

data collected prospectively as part of the New England Childrens Amalgam

Trial (NECAT). Data from this trial have already shown a greater need for

replacement of primary posterior restorations due to recurrent caries on the

same tooth surface after placement of compomer compared with amalgamrestorations (3.0% vs. 0.5%, p = 0.002) (Soncini et al., 2007). This finding may

have resulted from properties of compomer restorations, such as microleakage,

outweighing any potential beneficial effects of released fluoride. However, it

remains possible that fluoride from compomers succeeds in protecting other

teeth in the mouth. It is important to examine this possibility because, if there

is a benefit to compomer over amalgam in preventing future caries on other

surfaces, such a benefit may outweigh the risk of more frequent replacement of

compomers. Indeed, an assessment of dental material choice must consider the

overall picture of future dental procedures, including new restoration placement

as well as replacement of existing restorations.

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J Dent Res 88(3) 2009 Fluoride in Compomers and Future Caries 277

MATERIALS & METHODS

Study Design and Participants

A detailed discussion of the design of NECAT has been previously

published (The Childrens Amalgam Trial, 2003; Bellingeret al., 2006).

The study was approved by the institutional review boards of the New

England Research Institutes, The Forsyth Institute, and all dental

clinics. English-speaking children in Boston, MA, and Farmington,

ME, aged 6-10 yrs at baseline, were eligible if they had no known prior

or existing amalgam restorations, 2 posterior teeth with dental caries

requiring restorations on occlusal surfaces, and no clinical evidence of

existing psychological, behavioral, neurological, immunosuppressive,

or renal disorders. Parental consent and child assent were obtained for

534 children.

Dental Treatment and Clinical Procedures

A complete dental examination was scheduled every 6 mos during the

five-year trial, between September 1997 and March 2005. Participating

children were provided preventive and restorative dental care. Sealants

(Ultradent XT plus; Ultradent, South Jordan, UT, USA ) were placed on

all sound permanent and primary molars with deep pits and fissures and

were replaced as needed in all children. Restorations were continually

placed over the course of the trial as needed, according to assigned

treatment. Children were randomized to receive either amalgam (n =

267) or composite/compomer (n = 267) restorations at baseline and

during the course of the trial. For children assigned to the composite/

compomer group, compomer was placed in primary dentition, while

composite was placed in permanent dentition. For children in the

amalgam group, composite/compomer was used in the anterior dentition

if required by standard clinical practice guidelines. The amalgam

material used was Dispersalloy (Dentsply Caulk, Milford, DE, USA),

and the compomer material was Dyract (Dentsply Caulk).

One dentist (J.A.S.) treated 97% of the Boston-area participants, with

two additional dentists treating the remaining seven children at one

Boston site. Three dentists treated rural Maine participants during the

course of the trial. Clinical variability was minimized by centralized train-

ing of all dental personnel and the use of standard pediatric dental proce-dures as specified in the NECAT protocol and procedures manual. The

same technique was used in the placement of all restorations, with rubber

dam used the majority of the time. Following the complete removal of

decay, the tooth was acid-etched with 30% phosphoric acid for 20 sec and

washed thoroughly. A bonding agent (Optibond; Kerr, Orange, CA, USA)

that has a fluoride-release characteristic was applied and light-cured for

30 sec. The restoration was then placed according to the manufacturers

indications. Although fluoride-containing bonding agents are less com-

monly used in the placement of amalgam compared with compomer

restorations, the use of bonding agents had to be standardized in this

clinical trial (designed to compare the safety of the two types of materials

themselves), to eliminate possible confounding (e.g., by bonding agent).

Statistical Analysis

Only exposure to posterior primary restorations was considered for this

analysis, since NECAT used compomer only in primary teeth and

amalgam only in posterior teeth. However, determination of future caries,

after placement of the restoration, included all teeth (including permanent

and anterior teeth).

Each restoration contributed follow-up from the date of initial place-

ment to the date of exfoliation, extraction, or the childs last dental visit

(whether at year 5 or before withdrawal from the trial), whichever

occurred first. Because restorations were placed at the baseline dental

visit, as well as during follow-up visits over the five-year trial, the start of

follow-up time varied by restoration. We estimated the date of exfoliation

by averaging the dates of the last dental visit with the primary tooth and

the first dental visit with the corresponding permanent tooth; since dental

exams were performed every 6 mos and documented the status of each

tooth, the date of exfoliation is accurate to within 3 mos. Restorations

placed with no subsequent follow-up (i.e., at the last dental visit before

withdrawal, tooth exfoliation, or at the end of the trial; N = 80) were

excluded from all analyses and descriptive statistics.

The time from placement of each restoration to the development of

each new carious surface recorded while the initial restoration was still in

the mouth was calculated. There were two outcomes for this analysis: thetimes until (1) new caries on a different surface of the same tooth, and (2)

new caries on any different teeth. To test whether these outcomes varied

by type of restoration material (compomervs. amalgam, as treated), we

used a random-effects accelerated failure time model with proportional

hazards (Cox and Oakes, 1984). The models adjusted for the following

covariates when they were significant (p < 0.05) or changed the effect of

restoration material by > 10%: age, gender, socio-economic status (a

weighted average of household income and education), and the number of

restorations (of either type) in the mouth at the time the restoration was

placed. The random effect in this survival model was the child, to account

for the potential correlation between restorations in the same mouth.

Survival curves were plotted to show the percents of compomer and amal-

gam restorations that had future caries develop either on the same tooth or

on different teeth after placement through the follow-up time period.

RESULTS

At baseline, the average age of participants was 7.9 + 1.3 yrs

(Table). The mean number of total caries at baseline was 9.5

decayed tooth surfaces, of which 7.8 were in primary teeth and

1.7 were in permanent teeth. The sample was gender-balanced

and racially diverse.

Over the five-year trial, 1085 compomer and 954 amalgam

restorations with follow-up were placed on posterior primary

surfaces in 441 children (243 receiving compomer, 218 receiving

amalgam, with 20 receiving both). The average length of

restoration follow-up was 2.8 + 1.4 yrs, with a range of 0.03-6.3

yrs. Although this was a five-year study with dental visits every6 mos, children sometimes scheduled visits at longer intervals,

resulting in greater than 5 yrs of follow-up.

Survival curves for time until new caries after placement of

either compomer or amalgam restorations were plotted by treatment

group (Fig.). Random-effects survival analysis showed no significant

effect of dental material on new caries on the same tooth (p = 0.98,

Fig., a). However, there was a very small, but statistically significant

(p = 0.007), effect of dental material on new caries formed on

different teeth, with longer time until the formation of new caries

following placement of amalgam restorations (Fig., b).

In comparison of new caries following those primary

restorations with five-year follow-up (N = 211: 109 composite +

102 amalgam), amalgam was associated with a slightly higherpercentage of new caries on different surfaces of the same tooth

after 5 yrs of follow-up (17.7% vs. 14.7% of restorations). The

mean number of new caries on different teeth 5 yrs after

restoration placement was also slightly higher for amalgam (4.2

vs. 3.5 new carious surfaces). In analyses that examined the

percentage of sound teeth in the mouth at baseline that developed

caries during the five-year follow-up, there was no difference by

restoration material; 8.5% of sound teeth in either arm developed

caries. This relatively low percent may be explained by the

exfoliation of sound primary teeth over the five-year follow-up.

Almost all children presented with caries during follow-up,


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278 Trachtenberg et al. J Dent Res 88(3) 2009

follow-up, the mean number of new

caries on other teeth or on other surfaces

in the same tooth after placement of

compomer was actually slightly lower,

compared with amalgam. Thus, overall,

there was no clear or consistent effect of

these dental materials on the formation of

new caries on different surfaces/teeth inour study. We conclude that there does

not appear to be an advantage to the

fluoride-releasing compomer compared

with amalgam restorations placed with

the Optibond bonding agent for the

prevention of new caries in children.

A limitation in the generalizability of

these findings is that a bonding agent

(Optibond) with a fluoride-release

characteristic was used for all restorations,

such that all restored surfaces received

some fluoride exposure. Additionally, the

sealant used on children in both treatmentgroups also released fluoride into the

mouth. Therefore, this was a comparison

of compomer and amalgam in an oral

environment that had an unmeasured, but

relatively constant, base level of fluoride.

However, the Optibond bonding agent

releases fluoride into the tooth, as opposed

to the compomer restoration, which

releases fluoride into the mouth, resulting

in a different route of fluoride exposure.

Tale. Baseline Characteristics of New England Childrens Amalgam Trial Participants (N = 534),by Assigned Treatmenta

Baseline Characteristic Amalgam Group (n = 267) Composite Group (n = 267)

Study site, n (%)Boston 144 (53.9) 147 (55.1)Maine 123 (46.1) 120 (44.9)

Carious surfaces,mean (SD) range 9.8 (6.9) 2-39 9.3 (6.2) 2-36Age, mean (SD), yrs 7.9 (1.3) 7.9 (1.4)Gender, n (%)

Female 131 (49.1) 156 (58.4)Male 136 (50.9) 111 (41.6)

Race, n (%)bNon-Hispanic white 165 (64.0) 158 (60.3)Non-Hispanic black 49 (19.0) 49 (18.7)Hispanic 15 (5.8) 23 (8.8)Other 29 (11.2) 32 (12.2)

Household income, n (%) $20,000 74 (29.2) 86 (33.1)$20,001 - $40,000 113 (44.7) 109 (41.9)

> $40,000 66 (26.1) 65 (25.0)Education of primary caregiver, n (%)< High school 34 (13.2) 38 (14.6)High school graduate 197 (76.4) 194 (74.3)College graduate 18 (7.9) 17 (6.5)Post-college degree 9 (3.5) 12 (4.6)

a For race, data were available for 520 participants (N = 520); for income, N = 513; for education,N = 519.

b Race was self-reported by the parents of the children.

It is possible that either the small amount of fluoride released

into the tooth from the Optibond liner protects against future caries

in a magnitude similar to the fluoride-releasing properties of

compomer, or, despite the received benefit of additional fluoride

from compomer, compomer is still no more successful at preventing

future caries due to other properties. For example, the problem of

microleakage, common to compomer and composites, may be a

factor contributing to the formation of recurrent caries (Burgesset al.,

2002; Estafan and Agosta, 2003; Soncini et al., 2007). It has been

noted that despite the cariostatic effects possibly achieved from

fluoride-releasing materials, secondary caries is still one of the main

reasons for clinical failure of restorations (Wiegand et al., 2006).

Additional study comparing compomer with amalgam in

other oral environments would be worthwhile. Still, because

children with multiple dental treatment needs, as in our study,

are most in need of protection against future caries, the use of

fluoride agents at various levels of treatment may represent an

increasingly common standard of care (American Academy of

Pediatric Dentistry, 2005). In light of our findings, the evidence

to date suggests no advantage of compomer over amalgam in

protecting against the formation of future caries. Therefore,

although there is reason to prefer the use of compomer rather

than composite in primary teeth, because of the cariostatic

property of fluoride (Chung et al., 1998; Dionysopoulos et al.,

1998; Donly and Grandgenett, 1998; Hicks et al., 2000; Torii

et al., 2001; Attar and Onen, 2002; Gonzalez Ede et al., 2004;

Yaman et al., 2004), compomer does not perform better than

though often on teeth that were either already decayed or not

present in the mouth at baseline.

DISCUSSION

This paper presents, for the first time in a large sample, analyses

to compare the formation of future caries after placement of

compomervs. amalgam restorations. The NECAT data allowed

us to investigate this association properly, in vivo, by recruiting

a large cohort of children with a high rate of initial restorations,

randomly assigning them to amalgam or compomer, thus remov-

ing selection biases, and providing regular dental care during the

course of the five-year trial.

This dataset previously showed greater need for replacement

of primary posterior restorations due to recurrent caries on the

same tooth surface after placement of compomer compared with

amalgam restorations (3.0% vs. 0.5%, p = 0.002) (Soncini et al.,

2007). Adding to this, the current analysis demonstrated that,

under the restoration placement conditions of the trial, there was

no protective effect of compomer relative to amalgam in its ability

to prevent future caries on different surfaces/teeth. Rather, incident

caries on other teeth (i.e., other than the tooth where the restoration

was placed) appeared more quickly after the placement of

compomer restorations, but the difference, though statistically

significant, was very small, and the survival curves showed little

difference between compomer and amalgam at the end of

follow-up. In contrast, among restorations with a full 5 yrs of



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J Dent Res 88(3) 2009 Fluoride in Compomers and Future Caries 279

amalgam in this respect when amalgam is placed with a

fluoride-releasing bonding agent. Considering the results

presented here, together with our previously published results

on new restoration placement and replacement of existing

restorations (Soncini et al., 2007), our study suggests that

placement of compomer restorations in a high-risk population

results in more future dental needs compared with amalgam.

ACKNOWLEDGMENTS

The study was supported by the National Institute of Dental and

Craniofacial Research, Bethesda, MD, USA (U01 DE11886),

which also participated in the design and conduct of the study.

Trial Registration: Health Effects of Dental Amalgams in

Children, NCT00065988, http://www.clinicaltrials.gov/ct/show/

NCT00065988?order=1

REFERENCES

American Academy of Pediatric Dentistry (2005). Guideline on periodicity

of examination, preventive dental services, anticipatory guidance, and

oral treatment for children.Pediatr Dent27(7 Suppl):84S-86S.Asmussen E, Peutzfeldt A (2002). Long-term fluoride release from a glass

ionomer cement, a compomer, and from experimental resin composites.

Acta Odontol Scand60:93-97.

Attar N, Onen A (2002). Artificial formed caries-like lesions around esthetic

restorative materials.J Clin Pediatr Dent26:289-296.

Bellinger DC, Trachtenberg F, Barregard L, Tavares M, Cernichiari E,

Daniel D, et al. (2006). Neuropsychological and renal effects of dental

amalgam in children: a randomized clinical trial. J Am Med Assoc

295:1775-1783.

Burgess JO, Walker R, Davidson JM (2002). Posterior resin-based compos-

ite: review of the literature.Pediatr Dent24:465-479.

Burke FM, Ray NJ, McConnell RJ (2006). Fluoride-containing restorative

materials.Int Dent J56:33-43.

The Childrens Amalgam Trial Study Group (2003). The Childrens

Amalgam Trial: design and methods. Control Clin Trials 24:795-814.

Chung CK, Millett DT, Creanor SL, Gilmour WH, Foye RH (1998). Fluoriderelease and cariostatic ability of a compomer and a resin-modified glass

ionomer cement used for orthodontic bonding.J Dent26:533-538.

Cox DR, Oakes D (1984). Analysis of survival data. Monographs on statis-

tics and applied probability. London, UK: Chapman and Hall/CRC.

Dionysopoulos P, Kotsanos N, Papadogiannis Y, Konstantinidis A (1998).

Artificial secondary caries around two new F-containing restoratives.

Oper Dent23:81-86.

Donly KJ, Grandgenett C (1998). Dentin demineralization inhibition at

restoration margins of Vitremer, Dyract and Compoglass. Am J Dent

11:245-248.

Eichmiller FC, Marjenhoff WA (1998). Fluoride-releasing dental restorative

materials. Oper Dent23:218-228.

Estafan D, Agosta C (2003). Eliminating microleakage from the composite

resin system. Gen Dent51:506-509.

Gonzalez Ede H, Yap AU, Hsu SC (2004). Demineralization inhibition of

direct tooth-colored restorative materials. Oper Dent29:578-585.Grobler SR, Rossouw RJ, Van Wyk Kotze TJ (1998). A comparison of fluo-

ride release from various dental materials.J Dent26:259-265.

Hicks J, Garcia-Godoy F, Milano M, Flaitz C (2000). Compomer materials

and secondary caries formation.Am J Dent13:231-234.

Karantakis P, Helvatjoglou-Antoniades M, Theodoridou-Pahini S,

Papadogiannis Y (2000). Fluoride release from three glass ionomers, a

compomer, and a composite resin in water, artificial saliva, and lactic

acid. Oper Dent25:20-25.

Marczuk-Kolada G, Jakoniuk P, Mystkowska J, Luczaj-Cepowicz E,

Waszkiel D, Dabrowski JR, et al. (2006). Fluoride release and antibac-

terial activity of selected dental materials. Postepy Hig Med Dosw

(online) 60:416-420.

Marks LA, Weerheijm KL, van Amerongen WE, Groen HJ, Martens LC

(1999). Dyract versus Tytin Class II restorations in primary molars: 36

months evaluation. Caries Res 33:387-392.

Soncini JA, Maserejian NN, Trachtenberg F, Tavares M, Hayes C (2007).

The longevity of amalgam versus compomer/composite restorations in

posterior primary and permanent teeth: findings from the New England

Childrens Amalgam Trial.J Am Dent Assoc 138:763-772.

Torii Y, Itota T, Okamoto M, Nakabo S, Nagamine M, Inoue K (2001).Inhibition of artificial secondary caries in root by fluoride-releasing

restorative materials. Oper Dent26:36-43.

Wiegand A, Buchalla W, Attin T (2006). Review on fluoride-releasing

restorative materialsfluoride release and uptake characteristics, anti-

bacterial activity and influence on caries formation. Dent Mater

23:343-362.

Yaman SD, Er O, Yetmez M, Karabay GA (2004). In vitro inhibition of

caries-like lesions with fluoride-releasing materials. J Oral Sci 46:

45-50.

Ylp HK, Smales RJ (1999). Fluoride release and uptake by aged resin-

modified glass ionomers and a polyacid-modified resin composite.

Int Dent J49:217-225.

%o

frestorations

withnewcaries

ondifferentsurfaces

ofthesametooth

0

5

10

15

%o

frestorationswithnewcariesonadiffere

nttooth

0

20

40

60

80

100

compomeramalgam

compomeramalgam

years since placement of restoration

0 1 2 3 4 5 6

years since placement of restoration

0 1 2 3 4 5 6

a

b

Figure. Rates of new caries after restoration placement, by treatment group,in the New England Childrens Amalgam Trial (N = 2039 restorations).(a) Rate of new caries on a different surface of the same tooth. P = 0.98,calculated from a random-effects accelerated-failure time model with pro-portional hazards, adjusted for gender, socio-economic status, and numberof decayed and filled surfaces in the mouth. (b) Rate of new caries on adifferent tooth. P = 0.007, calculated from a random-effects accelerated-failure time model with proportional hazards, adjusted for age.



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