Clinical performance evaluation of a packable posterior composite in bulk-cured restorations

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Clinical performance evaluation of a packable posterior composite in bulk-cured restorations David C. Sarrett, DMD, MS; Carol N. Brooks, DDS; Jennifer T. Rose, DDS

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DISCLOSURE: This work was supported by a grant from Kerr (a subsidiary of Sybron Dental Specialties), Orange, Calif.

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J Background. The authors evalu✷ ✷  ated the clinical performance of Prodigy Condensable (Kerr, Orange, Calif.) composite placed and cured in N increments up to 5 millimeters thick. A U I N G E D U C 3 RT Methods. The authors placed 57 ICLE Class II restorations in 32 patients in composite increments up to 5 mm thick. Using this technique, they placed the majority of restorations in one increment and then carved the occlusal and proximal anatomy before light curing. The authors evaluated the restorations at three, six, 12, 24 and 36 months. Results. No restorations required replacement; however, 11 developed a defect requiring repair or continued observation. Of these 11, nine restorations developed defects on the margins of the restorations and two developed secondary caries. The Kaplan-Meier estimate of probability that a restoration would develop a defect during 36 months that would require immediate repair was 0.13. Postoperative sensitivity was not significantly different from preoperative sensitivity. Conclusions. The authors found that no restorations required replacement and no increased postoperative sensitivity occurred. Clinical Implications. The authors suggest that this composite material can be placed in a single increment up to 5 mm thick for Class II restorations. Key Words. Dental restorations; resin-based composite; light curing; posterior restorations. JADA 2006;137:71-80. A

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ABSTRACT CON

esin-based composites with viscosity higher than that of previous materials were introduced in the late 1990s to market to dentists who wanted to use a tooth-colored posterior restorative material that handled more like dental amalgam.1 A clinical challenge in placing Class II composite restorations is creating anatomically correct proximal contours and contact with adjacent teeth. Unlike amalgam, composite cannot be condensed to increase its density. Attempting to pack composite as a method of achieving adaptation of a matrix band to the adjacent tooth generally is not effective because the material will not increase in density and viscosity during placement. Without an increase in density, the material cannot resist the pressure applied by the matrix band, and the matrix band will return to its original shape; this may result in an open proximal contact when the matrix band is removed. So-called “packable” or “condensable” (“condensable” being a misleading term because the material’s density does not increase) composite materials have a noticeable stiffness that may allow them to be placed the same way as dental amalgam is placed. A potential drawback to these stiffer materials is their limited ability to adapt to internal cavity wall surfaces and to cavity margins. The presence of postoperative sensitivity indirectly may indicate poor ability of the dentin adhesive combined with the restorative material to adapt to internal walls and seal the dentinal tubules. It also is known that fracture is a common reason for failure of posterior com-

Dr. Sarrett is a professor of dentistry and the associate vice president for health sciences, Virginia Commonwealth University, 1012 E. Marshall St., PO Box 980549, Richmond, Va. 23298-0549, e-mail “[email protected]”. Address reprint requests to Dr. Sarrett. Dr. Brooks is an associate professor, School of Dentistry, Virginia Commonwealth University, Richmond. Dr. Rose is a dentist in private practice, Richmond, Va.

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posite restorations.2 Packable composites do not have substantially better mechanical properties than do hybrid composites1,3 and would not be expected to perform better clinically in this respect. Because the packing technique can introduce air bubbles into a composite restoration made of such restorations may have a greater potential to fracture than may restorations made of hybrid composite materials. Sarrett4 provided a more complete review of the clinical challenges associated with posterior composite restorations. Lopes and colleagues5 evaluated two packable posterior composites and found after two years that six to 12 percent of restorations had some margin adaptation defects and five to 11 percent showed margin discoloration. Two of 74 restorations had margin adaptation defects that required operative intervention. The other parameters evaluated showed acceptable clinical performance at two years. Ernst and colleagues6 evaluated one packable composite and found that 79 percent of the studied restorations were acceptable at three years, and 16 percent of the restorations had margin adaptation defects that required intervention. They found secondary caries in 3.5 percent of the restorations, and margin discoloration in 28 percent. The material tested by Ernst and colleagues6 no longer is available in the formulation they tested. In a review of 24 clinical studies of posterior composites, Brunthaler and colleagues2 found only two studies that listed margin defects as a main reason for failure; one of these studies involved packable composites. These authors analyzed all types of restoration failure and found no differences in the failure rate for packable composites compared with the rates of other composite materials in the 24 studies reviewed; however, the studies of packable composites were all three years or less in duration compared with studies of the other composite materials, which were as long as 17 years. A study evaluating the use of a flowable composite before placement of the packable composite found no differences in survival rates of restorations placed with or without a flowable composite layer between the adhesive and the packable composite.7 The overall survival rate after two years was 94 percent. The reasons for failure were margin adaptation defects, secondary caries, fracture and degradation of surface finish. Three of 116 (3 percent) restorations fractured. Ernst and 72

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colleagues6 reported a 9 percent fracture rate of a packable composite over three years, with 60 percent of the fractures being in molar restorations. Loguercio and colleagues8 evaluated four packable composites over one year and reported marginal ridge fractures in 1 percent of restorations made with the same brand of material as studied by Ernst and colleagues.6 Loguercio and colleagues8 observed no fractures for the remaining three packable composites they studied; however, restorations made with a nonpackable composite in that study showed that 28 percent of the restorations developed small fractures. Overall, two of the three packable composites in this study had acceptable clinical performance after one year. Three other studies9-11 evaluated one of the materials found acceptable by Loguercio and colleagues8 and found 94 to 100 percent survival over 12 to 24 months. One of these three studies10 reported 6 percent and another11 reported 3 percent fracture of restorations made with this same packable composite. Brunthaler and colleagues2 found that five of the 24 studies they reviewed reported postoperative pain as a reason for failure; two of those five studies found postoperative pain to be the primary reason for failure. In the two studies in which postoperative pain was the main reason for failure, one was a study of direct composite inlay placement and the other was a study of ultraviolet–light-cured materials. Ernst and colleagues6 reported a 4.8 percent rate of replacement of packable composite restorations over three years owing to postoperative sensitivity. Loguercio and colleagues8 and Türkün and colleagues10 reported no problems with postoperative sensitivity, whereas subjects in the study by Yip and colleagues11 had sensitivity in 9 percent of the restorations made with a packable composite versus in 3 percent of the restorations made with a nonpackable material. The American Dental Association Acceptance Program Guidelines: Resin-Based Composites for Posterior Restorations12 include designations of Type A and B materials. The guidelines suggest the unrestricted use of Type A materials in restoring posterior teeth, including for cuspal replacement. For acceptance as a Type A material, the ADA requires 18-month clinical data from studies that include at least 30 Class I and II restorations of a buccal and/or lingual surface. Failure rates must be no greater than 5 percent in terms of margin integrity and sec-

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ondary caries and no greater than 10 percent in tions and placed the composite restorations. We terms of margin discoloration and bulk color. The used rubber dam isolation in all cases, usually ADA also requires evidence that there were no after the majority of cavity preparation was combulk fractures and no restoration loss. Type A pleted. The occlusal portion of the cavity was at materials also must meet a series of laboratory least 2 mm deep and the axial wall was prepared test standards. For Type B materials suggested so that it extended into dentin. Proximal contact for use in Class I and II restorations, only the labwas broken on the majority of teeth with a minoratory testing is required. Thus, it is difficult to imum of 0.5 mm extension from adjacent teeth in compare the results from previous clinical studies facial, gingival and lingual locations. We rounded of packable composites with the current ADA line angles by using no. 330 and round burs for guidelines for Type B materials to determine cavity preparation and caries removal. acceptable clinical outcomes. It appears that a We applied a metal matrix before initiating the restoration replacement rate of greater than 10 to bonding procedure. We placed the majority of res15 percent after 18 to 36 months is clinically torations using a matrix system with a dead softunacceptable. The most common defects that sectional metal matrix, wedge and a Palodent require replacement are secondary caries, bulk BiTine (Dentsply International, York, Pa.) ring. fracture or total restoration loss, or unresolved When we placed practice restorations using a cirpostoperative sensitivity. One further complicacumferential matrix and wedges for tooth separation is how to handle composite restion, we did not routinely achieve toration defects that can be satisfactory proximal contours and repaired easily to ensure that the contacts. We used Optibond Solo The most common restoration continues to serve the (Kerr) adhesive system according to defects that require patient well for years. There are no the directions supplied by the manrestoration current standards or guidelines ufacturer. We applied light-cured replacement are regarding an acceptable repair glass ionomer base to only four cavirate. secondary caries, bulk ties before placing the adhesive. We We evaluated the clinical perchose the appropriate shade of comfracture or total formance of Prodigy Condensable posite and placed the restoration in restoration loss, (Kerr, Orange, Calif.) composite. one increment when the thickness or unresolved The manufacturer’s directions indiwas 5 mm or less by injecting the postoperative cate that increments up to 5 milmaterial directly from the supplied sensitivity. limeters may be placed and cured, unidose cartridges. Using this techand that sculpting of the restoranique, less than 10 percent of restotion may be completed before rations required more than one curing. We included these two components in the increment, and we created the majority of the protocol for placing the restorations. We were final occlusal and proximal anatomy before light keenly interested in clinical signs of undercured curing. We used a burnisher and amalgam composite and polymerization shrinkage; these carvers lubricated with Optiguard resin (Kerr). signs included bulk composite fracture or loss of We first cured the restorations from the occlusal restorations, postoperative pain and cuspal fracaspect for 40 seconds using an Optilux 501 lighttures. curing unit (Kerr). After removing the matrix, we then cured the restorations for 40 seconds from MATERIALS AND METHODS each proximal wall of the restoration. For We placed a total of 57 Class II restorations in 32 example, we cured a mesial-occlusal restoration patients in teeth with opposing natural occlusion. 40 seconds from the occlusal aspect, 40 seconds One of the authors (DCS) placed all restorations from the mesiobuccal aspect and 40 seconds from in the Advanced Education in General Dentistry the mesiolingual aspect, for a total curing time of (AEGD) clinic at Virginia Commonwealth Univer120 seconds. We measured the curing light intensity (VCU) School of Dentistry, Richmond. AEGD sity just before curing each restoration with a residents administered anesthetic, placed rubber Demetron radiometer (Kerr) to ensure that it dams and prepared some cavities; however, one always was at least 500 milliwatts per square faculty member with more than 20 years of expecentimeter. We performed occlusal adjustment rience (again, DCS) completed all cavity preparawith carbide burs, and we polished the restoraJADA, Vol. 137 http://jada.ada.org Copyright ©2006 American Dental Association. All rights reserved.

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TABLE 1

tions at the three-month recall appointment, which Teeth in the study, by type and number of restorations. was the baseline examination for the study. Before NO. (%) OF RESTORATIONS, BY NO. OF SURFACES TOOTH TYPE ROW TOTALS the first recall visit, the two examiners practiced using Two Three Four the criteria by examining 19 (33) 14 (25) 0 (0) 33 (58) Premolar patients with posterior composite restorations. During 18 (32) 4 (7) 2 (3) 24 (42) Molar the practice sessions, they 37 (65) 18 (32) 2 (3) 57 (100) COLUMN TOTALS discussed differences in judgments to achieve a conTABLE 2 sensus evaluation. They recorded the data on a form Preoperative conditions of teeth in the study. that included a complete copy of the modified PHS criNO. OF TEETH PREOPERATIVE CONDITION teria. The examiners did not WITH CONDITION have access to the data from 38 Replaced Existing Amalgam their previous evaluations. Restoration They used a mirror, an 5 Replaced Amalgam Restoration Owing explorer and magnification to Secondary or Proximal Caries glasses to assess all clinical 7 Replaced Existing Composite parameters, and the patients Restoration brushed their teeth before 7 Restored Owing to Proximal Caries being examined. At each recall visit, the examining authors evaluated surface appearance, color match, anatomical form tions with diamond paste. We then etched and (occlusal contours, proximal contact and retention), sealed the restorations, as well as 1 to 2 mm of surrounding enamel, with Optiguard resin. margin integrity (adaptation—tactile, adaptaTables 1 through 4 provide descriptive data on tion—visual, discoloration and caries) and sensithe teeth restored and the materials used. The tivity. They measured tooth sensitivity before youngest patient was 21 years old, the oldest placing each restoration and at each recall visit. patient was 72 years old, and the median age was The patient rated his or her discomfort on a scale 33 years. About one-half of the patients were 20 to of 0 (no sensitivity) to 10 (the worst pain he or she 39 years of age. Exclusion criteria for patient selechad ever felt) after receiving a three-second blast of tion included pregnancy and serious chronic disair to the restored tooth. At the first recall visit, we eases that would not allow for routine restorative asked the patients if they had postoperative sensidentistry. Most of the patients were regular tivity during the first week after the placement of patients of the VCU School of Dentistry and the restoration. included VCU students. None of the patients were We analyzed the modified PHS data by calcuconsidered to be at high risk of developing dental lating percentages of restorations scored R, S, T or caries. All patients signed an informed consent V for each clinical criterion.4 We performed form and this research was approved by the VCU χ2 analyses to compare the clinical criteria and Institutional Review Board. analysis of variance with the mean postoperative We recalled the patients at three, six, 12, 24 and sensitivity across all recall periods. We used the 36 months, and two of the authors (CNB and JTR) Kaplan-Meier method to estimate two functions for evaluated the restorations using modified U.S. the probability that a restoration would require Public Health Service (PHS) criteria4,13,14 based on some continued observation or intervention over 36 the R, S, T, V scoring system. Table 5 (page 76) months. One function was for the probability that describes the definitions for the rating scale, and a restoration would develop a T- or V-score defect; Sarrett4 fully described the details of each critethe second function was for the probability that a rion. We examined 53 of the original 57 restorarestoration would develop only a V-score defect. We 74

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used the first occurrence of a T or V score for each restoration to estimate the above probabilities. We used an alpha level of .05 for all statistical analyses. RESULTS

TABLE 3

Details about material used in the study. NO. OF RESTORATIONS

8

COMPOSITE SHADE

MANUFACTURER’S LOT NO.

A1

811523

At the six-, 12-, 24- and 36-month A2 811800 16 recall appointments, we evaluated A3 811524 10 50, 43, 43 and 25 restorations, respectively (Table 6, pages 77 and B1 811602 8 78). The percentage range of preC1 811522 2 molar restorations evaluated D2 810859 13 across the recall periods was 53 to 60 percent and of molar restoraAdhesive 811299 30 tions was 40 to 47 percent. The Adhesive 812163 27 percentage range of two-, threeSealer 810345 57 and four-surface restorations evaluated across the recall periods were 64 to 72 percent, 24 to 33 per- TABLE 4 cent, and 2 to 4 percent, respecMatrix types used in the study. tively. The median age of the patients at each recall visit ranged NO. OF RESTORATIONS MATRIX SYSTEM from 28 (at the 12-month recall PLACED USING EACH SYSTEM visit) to 45 (at the 36-month recall visit) years. 47 Sectional Matrix With Wedge and Bitine Ring Table 6 presents the results in percentages of each score—R, S, T 10 Circumferential Matrix With Wedge and V—for each criterion for all restorations we evaluated at each recall appointwhich two were due to secondary caries and three ments. The χ2 analyses of the data in Table 6 indiwere due to marginal defects. cated that there was a significant difference in the The Kaplan-Meier analyses showed that for this criteria for surface. The surface appearance was composite, the probability that a restoration would rougher at six months than at the other recall develop a V-score defect by 36 months was 0.13 points. There were no other significant differences and the probability that a restoration would in the other clinical criteria across all recall develop a T or V score was 0.24. We did not replace periods. A total of 19 restorations developed a T- or any restorations during the study for any reason, a V-score defect. Eight of these restorations scored and we kept in the study any restorations that T or V only because of proximal contacts’ not being were repaired. tight; two other restorations also developed open Seventy-three percent of patients reported no contacts. Four of the open contacts were adjacent sensitivity during the first week after placement of proximal restorations in the study. We determined restorations. The mean preoperative sensitivity from the patient’s history and the appearance of caused by a three-second air blast was 0.35 with a the proximal contours that wear of the material standard deviation of 1.03. This was not statisticaused none of the open contacts. Seven of the 10 cally different from the mean sensitivity at three, were caused by orthodontic treatment, two by six, 12, 24 or 36 months, which were 0.40 changes in occlusion from other restorative pro(± standard deviation 1.15), 0.50 (± 1.02), 0.51 cedures and one by unexplained factors. We attrib(± 1.22), 0.30 (± 0.91) and 0.76 (± 1.36), respecuted T- or V-score defects of 11 restorations to true tively. issues related to the composite material. Of these DISCUSSION 11 restorations, six developed only T-score defects caused by chipping of the material near margins. The number of patients we examined and restoraFive restorations developed a V-score defect, of tions we evaluated at each recall visit decreased JADA, Vol. 137 http://jada.ada.org Copyright ©2006 American Dental Association. All rights reserved.

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TABLE 5

Operational definitions for the modified U.S. Public Health Service rating criteria. OPERATIONAL DEFINITION

RATING Satisfactory R: Excellent

The restoration is of satisfactory quality and is expected to protect the tooth and surrounding tissue.

S: Acceptable

The restoration is of acceptable quality but exhibits one or more defects which deviate from ideal. Not Satisfactory

T: Monitoring or intervention required

The restoration is not of acceptable quality. Future damage to the tooth and/or its surrounding tissues likely to occur. The restoration is not of acceptable quality. Damage to the tooth and/or its surrounding tissue is now occurring.

V: Replacement or immediate correction needed

over time. This is a typical problem with these types of clinical studies, and it can lead to bias in the sample available for evaluation in the later years of the study. We experienced deviation of 8 percent or less in the tooth type and restored surfaces distributions between the baseline recall appointments and all other recall periods. This likely had limited impact on our results. The median age of patients at restoration placement was 33 years; the greatest deviation from this value was 45 years at the 36-month recall appointment. The range of median age at the other recall appointments was 28 to 35 years. The increased median age of patients at the 36-month recall visit may have introduced some bias in the 36-month results. Surface appearance. The percentage of R scores for surface appearance decreased from 81 percent at three months to 58 percent at six months and, ultimately, returned to 96 percent at 36 months (Table 6). This material maintained its viscosity during placement and shaping. Slumping that usually occurs when composite warms to mouth temperature did not prevent us from sculpting the anatomical contours before light curing. We believe the increase in surface roughness between three and six months was caused by the initial loss of the sealed surface, which exposed the carved surface. The carved surface had rough areas that were filled in by the sealer. The sealed surface initially appeared glossy and created an illusion of smoothness; however, the gloss wore off in the first six months. We observed a subsequent increase in the percentage of R scores, indicating a smoother 76

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surface appearance, which we believe was caused by a self-polishing effect of wear that resulted in smoothing out the rough areas left by our carving. Color. Color matching and stability met ADA guidelines12 during the study period, with 91 percent of the restorations having R scores at 24 months and 80 percent of the restorations having R scores at 36 months with no T or V scores occurring at either time interval (Table 6). Anatomical form. Occlusal contours. We also observed that 66 to 81 percent of the restorations scored R for anatomical form—occlusal contours. We believe this was caused mainly by our placement technique, which created the majority of the occlusal contour before curing the composite. This left some excess contour at the margins, resulting in 66 percent of the resotrations receiving an R rating at three months (Table 6). This excess wore during function and increased the score to 81 percent at 12 months. Subsequently, continued three-body wear caused by mastication resulted in some slightly undercontoured areas, and we observed that the percentage of restorations having R scores decreased to 68 percent at 36 months. The 2 percent of restorations that had T scores and 4 percent that had V scores at 24 and 36 months, respectively, for occlusal contours are within the ADA guidelines.12 Proximal contact. We found that despite the material’s higher viscosity in comparison with that of nonpackable composite, we could not achieve satisfactory proximal contacts routinely by using only a metal circumferential matrix band and separation of the teeth with a wedge. We used a bitine ring and dead soft metal

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TABLE 6

Clinical evaluation data using modified U.S. Public Health Service (PHS) criteria.* PERCENTAGE OF RESTORATIONS BY RECALL PERIOD, IN MONTHS

U.S. PHS CRITERION AND SCORE†

Three (n = 53)

Six (n = 50)

12 (n = 43)

24 (n = 43)

36 (n = 25)

Surface and Color Surface R

81

58

74

72

96

S

19

40

26

28

4

T

0

2

0

0

0

V

0

0

0

0

0

R

98

90

88

91

80

S

2

10

12

9

20

T

0

0

0

0

0

V

0

0

0

0

0

Color

Anatomical Form Occlusal Contours R

66

78

81

75

68

S

32

22

19

23

28

T

2

0

0

2

0

V

0

0

0

0

4

R

84

78

81

88

72

S

8

16

12

5

8

T

8

4

2

0

12

V

0

2

5

7

8

R

100

100

98

96

92

S

0

0

0

0

0

T

0

0

2

2

4

V

0

0

0

2

4

Proximal Contact

Retention

Continued on next page matrices for the majority of the teeth we restored (Table 4). We observed 10 restorations with open contacts over the 36 months, none of which we attributed to wear or other loss of composite material. Our study included dental students who decided to receive orthodontic treatment after res-

toration placement, resulting in seven of the open contacts. Despite this drawback to our study, the data from the other patients indicated that maintenance of proximal contact was satisfactory. Retention. An assessment of restoration retention evaluates partial and total restoration loss

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TABLE 6 (continued)

Clinical evaluation data using modified U.S. Public Health Service (PHS) criteria.* PERCENTAGE OF RESTORATIONS BY RECALL PERIOD, IN MONTHS

U.S. PHS CRITERION AND SCORE†

Three (n =53)

Six (n = 50)

12 (n = 43)

24 (n = 43)

36 (n = 25)

Margin Integrity Adaptation—tactile R

60

62

54

40

48

S

36

34

44

51

44

T

4

2

2

2

0

V

0

2

0

7

8 (16‡)

R

98

96

95

88

84

S

2

2

5

10

12

T

0

2

0

2

4

V

0

0

0

0

0

R

98

90

86

84

88

S

2

10

14

16

12

T

0

0

0

0

0

V

0

0

0

0

0

R

100

100

100

98

96

S

—

—

—

—

—

T

—

—

—

—

—

V

0

0

0

2

4 (8§)

Adaptation—visual

Discoloration

Caries

* Percentages of scores are based on the number of restorations evaluated at each recall. † R: Excellent. S: Acceptable. T: Monitoring or intervention required. V: Replacement or immediate correction needed. ‡ Includes data from two restorations found to have marginal failures at 24 months that were repaired and remained in the study. If these two were continued to be counted as marginal failures for this recall, the percentage would be 16. § Cumulative percentage of V scores for caries or a total of two restorations observed with caries during study.

and bulk fracture of the composite. We found no restorations that were lost totally during the study; the percentage of R scores for retention was 98 percent and 96 percent, respectively, at 24 and 36 months (Table 6). The 4 percent failure (2 percent T scores and 2 percent V scores) at 24 months is well within the 5-percent-at-18-months limit specified in the ADA guidelines.12 The 4 percent T scores and 4 percent V scores for retention at 36 months were due to partial loss of material from two restorations. This rate of fracture is in the 3 to 9 percent range reported by others for packable 78

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composites6-8 and indicates that this material, cured in thicknesses up to 5 mm, was cured sufficiently to withstand occlusal forces. If the material did not cure adequately in the deeper area of the restorations, we would have expected to see bulk fractures into the poorly cured layer in the early months of the study. Margin integrity. Adaptation—tactile. We evaluated marginal adaptation using an explorer to detect crevices and contour mismatches at the interface between the tooth and the composite. Our data in Table 6 show the baseline percentage

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R E S E A R C H

of R scores for adaptation—tactile was 60 percent terion. Our data illustrate the difficulty of seeing and then decreased to 48 percent at 36 months. As marginal changes because of the color and transluwe did with occlusal contours, we detected excess cency match between the composite and enamel. composite at margins during the first year. This Discoloration. We found no T- or V-score defects likely occurred because of the method we used, in for margin discoloration and, thus, no failures for which we shaped the majority of the occlusal this criterion. The ADA guidelines12 require no anatomy with carvers before curing the composite. more than 5 percent failures for margin discolAs wear from mastication occurred, the excess oration at 18 months. material at the margins disappeared and some Caries. We did not detect any secondary caries areas of slight undercontour at the marginal until the 24-month recall visit when one restoraresulted in the increase of percent S to 44 percent tion (2 percent V in Table 6) had caries at a bucat 36 months. We speculate that the net result of cogingival line angle where the marginal was in these two mechanisms explains why we did not see dentin. We found one more case of secondary any significant difference in marginal adaptation caries at the 36-month recall appointment in over time. another patient resulting in a cumulative 8 perThe ADA guidelines12 require margin integrity cent V (Table 6). Our data are within the range of failures to be no more than 5 percent at 18 months 3.5 to 13 percent failure owing to secondary caries for a Type A composite. At 12 in studies with observation periods months, 2 percent of restorations up to five years2 and less than 5 perhad a T-score defect for marginal cent at 18 months to meet the ADA This material likely adaptation; at 24 months, we guidelines.12 would meet the ADA observed some areas of crevice forPostoperative sensitivity. standard for margin mation and marginal fractures that Brunthaler and colleagues2 reported integrity failures and allowed penetration with an failures due to postoperative sensiexplorer, resulting in 9 percent (2 tivity of 2 to 8 percent in five of the are in the range of 6 percent T and 7 percent V) of resto24 studies they reviewed. These to 16 percent at 24 rations requiring intervention. studies ranged in length from 1 to 17 months reported in These data indicate that this years. The remaining 19 studies other studies for material likely would meet the 18reported no postoperative sensitivity packable composites. month ADA standard and are in the failures. Our data are similar in that range of 6 to 16 percent at 24 no restorations failed because of months reported in other studies for postoperative sensitivity. We found packable composites.5,6 The bulk curing method we that 73 percent of patients reported experiencing used does not appear to have resulted in increased no postoperative sensitivity during the first week margin adaptation failures as might have been after placement of the restorations, and there were expected. At 24 months, two of the restorations no significant differences in the sensitivity meawith V-score defects in the same patient occurred sured preoperatively versus postoperatively at all at the buccogingival line angle of molar restorarecalls periods. In our protocol, we cured the tions. We decided to repair these areas and conmajority of restorations in bulk up to 5 mm in tinue to follow the restorations. At 36 months, the thickness, which likely created more polymerizarepaired areas were intact and required no further tion contraction stresses in the teeth. It might be treatment. The double dagger symbol next to the expected that this method would lead to problems 36-month data for “adaptation—tactile” in Table 6 with postoperative sensitivity; however, this was not the outcome. It is critical to note that we used indicates that the data include the two repaired a curing light with at least 500 mW/cm2 output restorations. Composite restorations offer a distinct advantage over other materials: the option of and multiple curing cycles of 40 seconds, which are repairing defects rather than replacing the entire important factors in the results we obtained. restoration. Weaker curing lights, shorter curing times or both Adaptation—visual. Margin integrity evaluated may not yield the same outcomes. by the “adaptation—visual” criterion (Table 6) CONCLUSION indicated higher values of percentage of restorations with R scores compared with values seen We evaluated the clinical performance of Prodigy with an evaluation by the “adaptation—tactile” criCondensable composite when placed and cured in JADA, Vol. 137 http://jada.ada.org Copyright ©2006 American Dental Association. All rights reserved.

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increments up to 5 mm thick in Class II restorations. No restorations required replacement; however, the probability over 36 months that a restoration developed a defect requiring an immediate repair was 0.13. The most frequent reason we observed for needing repair was defects on margins. Two restorations developed secondary caries after 24 months. We found no increase in the mean postoperative sensitivity compared with the mean preoperative sensitivity. On the basis of these limited results, we suggest that this composite material can be placed and cured as a single increment for most Class II restorations, and its performance should meet the ADA guidelines for posterior composites. For this packable composite material, curing in bulk facilitates the placement of the material and prevents creating fins of material being packed between a cured layer and the matrix. Before light curing, anatomical shaping of the occlusal surface minimizes the need for carving with rotary instruments. We recommend that further research on the clinical outcomes of bulk-cured restorations be completed before any suggestion is made that this technique may be used with other composite materials. ■ 1. Leinfelder KF, Bayne SC, Swift EJ Jr. Packable composites:

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overview and technical considerations. J Esthet Dent 1999;11(5):234-49. 2. Brunthaler A, Konig F, Lucas T, Sperr W, Schedle A. Longevity of direct resin composite restorations in posterior teeth. Clin Oral Investig 2003;7(2):63-70. 3. Cobb DS, MacGregor KM, Vargas MA, Denehy GE. The physical properties of packable and conventional posterior resin-based composites: a comparison. JADA 2000;131(11):1610-5. 4. Sarrett DC. Clinical challenges and the relevance of materials testing for posterior composite restorations. Dent Mater 2005;21(1): 9-20. 5. Lopes LG, Cefaly DF, Franco EB, Mondelli RF, Lauris JR, Navarro MF. Clinical evaluation of two ‘packable’ posterior composite resins: two-year results. Clin Oral Investig 2003;7(3):123-8. 6. Ernst CP, Martin M, Stuff S, Willershausen B. Clinical performance of a packable resin composite for posterior teeth after 3 years. Clin Oral Investig 2001;5(3):148-55. 7. Ernst CP, Canbek K, Aksogan K, Willershausen B. Two-year clinical performance of a packable posterior composite with and without a flowable composite liner. Clin Oral Investig 2003;7(3):129-34. 8. Loguercio AD, Reis A, Rodrigues Filho LE, Busato AL. One-year clinical evaluation of posterior packable resin composite restorations. Oper Dent 2001;26(5):427-34. 9. Perry RD, Kugel G. Two-year clinical evaluation of a high-density posterior restorative material. Compend Contin Educ Dent 2000;21(12):1067-72, 74, 76 passim; quiz 80. 10. Türkün LS¸, Türkün M, Ozata F. Two-year clinical evaluation of a packable resin-based composite. JADA 2003;134(9):1205-12. 11. Yip KH, Poon BK, Chu FC, Poon EC, Kong FY, Smales RJ. Clinical evaluation of packable and conventional hybrid resin-based composites for posterior restorations in permanent teeth: results at 12 months. JADA 2003;134(12):1581-9. 12. American Dental Association. ADA acceptance program guidelines: Resin based composites for posterior restorations. Chicago: ADA Council on Scientific Affairs; 2001. 13. Ryge G, Snyder M. Evaluating the clinical quality of restorations. JADA 1973;87(2):369-77. 14. Cvar J, Ryge G. Criteria for the clinical evaluation of dental restorative materials. San Francisco: U.S. Department of Health, Education, and Welfare, Public Health Service, National Institutes of Health, Bureau of Health Manpower Education, Division of Dental Health, Dental Health Center; 1971. U.S. Public Health Service publication 790-240.

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