JADA Continuing Education
A three-year clinical evaluation of two dentin bonding agents
BRUCE A. MATIS, D.D.S., M.S.D.,
MICHAEL J. COCHRAN, D.D.S., M.S.D.,
TIMOTHY J. CARLSON, D.D.S., M.S.D.,
CHRISTANNE GUBA, D.D.S., M.S.D. and
GEORGE J. ECKERT, M.A.S.
 |
ABSTRACT
|
|---|
Background. A new restorative called a "giomer composite" has been introduced. The authors conducted a study to determine retention, anatomical form, caries, staining, marginal discoloration, marginal adaptation, surface roughness and sensitivity of giomer compared with those of a microfilled composite.
Methods. The authors placed 40 sets of restorations randomly in canines and pre-molars in vivo. They used a giomer composite and a microfilled composite in erosion/abrasion/abfraction Class V lesions that were not altered with rotary instruments. They placed the restorations according to manufacturer’s recommendations, and two calibrated examiners evaluated the restorations independently using modified U.S. Public Health Service criteria at baseline and at six, 18 and 36 months. The lesions receiving the restorations did not differ from each other in the amount of circumferential enamel present, the percentage of the surface area of dentin or lesion type.
Results. There were no differences in the restorations at baseline, an evaluation made two weeks after placement. At 36 months, the giomer and microfilled composite restorations were not significantly different from one another in any of the eight criteria evaluated. The percentage agreement between examiners was at least 83 percent for each criterion in each evaluation period.
Conclusions. Both the giomer and the microfilled composite used in this study meet the clinical portion of the Acceptance Program Guidelines for Dentin and Enamel Adhesives Materials established by the American Dental Association.
Clinical Implications. Both the giomer and the microfilled composite used in this study can be used with confidence in Class V lesions.
New materials are being introduced to address the need for restoring cervical lesions, both carious and noncarious (caused by a combination of abrasion, erosion and abfraction1). In an era when more and more patients are retaining their natural dentition, the need for this type of Class V restoration is increasing. The ideal material should be adhesive, tooth-colored and abrasion-resistant.
Both the giomer and the microfilled composite used in this study can be used with confidence in Class V lesions.
Class V lesions present many challenges in bonding. Traditionally, dentin adhesion has not been shown to be as predictable or strong as enamel bonding.2,3 Glass ionomer materials have shown better bonding to dentin than have resin-based composite materials. 4 A new class of fluoride-releasing resin materials with "prereacted glass," or PRG, has been introduced with claims of good color matching and decreased microleakage and increased fluoride release as compared with other resin materials.
We conducted a study to compare a product that belongs to this new class of materials, a hybrid of glass ionomer and resin-based composite called "giomer," with a microfilled resin-based composite material. The giomer material we used was Beautifil (Shofu, Kyoto, Japan) and the microfilled resin-based composite was Silux Plus (3M Dental Products, St. Paul, Minn.). (Author’s note: this product is no longer being manufactured, but other microfilled materials are available.) This study was approved by the institutional review board of Indiana University-Purdue University Indianapolis.
|
SUBJECTS, METHODS AND MATERIALS
|
|---|
We recruited patients seeking treatment at the Indiana University School of Dentistry, Indianapolis, to participate in the study. From those we recruited, we selected subjects with at least two noncarious premolars or canines with abrasion/erosion/abfraction lesions who met the inclusion/exclusion criteria (Box
). We restored 40 sets of lesions and placed no more than two sets of restorations in the dentition of each subject. We classified the lesions as being saucer-shaped or V-shaped. We also classified them as to the circumferential enamel on the lesions (as required by the American Dental Association guidelines for dentin and enamel adhesive materials5). The three categories of circumferential enamel were less than 40 percent, 40 to 60 percent and greater than 60 percent.
All subjects received a dental prophylaxis at least two weeks, but not longer than three months, before placement of restorations. For each subject, we chose the two lesions that were most similar in which to place the restorative materials, in random order. We did not alter the lesions with rotary instruments, and we followed manufacturer’s instructions strictly except for the recommendation of a beveled margin on the occlusal-incisal line angle. The American Dental Association’s5 Acceptance Program Guidelines for Dentin and Enamel Adhesive Materials do not allow the placement of bevels. We cleaned all lesions with pumice before placing the dam, to remove the pellicle and any stain that might have accumulated between the time of the dental prophylaxis and the placement of the restorations.
All procedures took place with rubber dam isolation. When the dam did not retract the tissues sufficiently on the lateral borders, we placed a short length of retraction cord in those areas to expose the lesion more clearly. We prepared FL-Bond (Shofu) before placing the Beautifil restoration by dispensing equal amounts of FL-Bond Primer A and B (Shofu) in a well and mixing them. We placed the mixture and air-dried it for 10 seconds with a mild stream of air. Then we applied adhesive and light-cured it for 10 seconds.
We applied Scotchbond Multi-Purpose Plus Dental Adhesive (3M Dental Products) before applying Silux Plus. We etched the lesion for 15 seconds with 37 percent phosphoric acid and rinsed it for 15 seconds. We removed excess surface moisture with a gentle stream of air for five seconds. We then placed primer on the dentin and enamel and dried it gently for five seconds. Then we applied adhesive and light-cured it for 10 seconds.
We placed either Beautifil or Silux Plus in the lesions immediately after applying their specific bond adhesives. If the lesion depth was greater than 2 millimeters, we layered and polymerized the restoratives in increments. We cured each layer for 40 seconds. The finishing of the giomer and microfilled composites consisted of using a no. 15 scalpel blade to remove any excess from the cervical aspect, in approximation to where the retainer clamp rested. When necessary, we recontoured the giomer resin using Super-Snap (Shofu Inc.) disks and the microfilled resin using Sof-Lex disks (3M ESPE Dental Products).
Subjects returned in two weeks (which we considered baseline), six months, 18 months and 36 months to undergo evaluation of the restorative materials. We used modified U.S. Public Health Service criteria6 (Table 1, page 452) to determine retention, anatomical form, caries, staining, marginal discoloration, marginal adaptation, surface roughness and sensitivity. Evaluators (M.J.C. and T.J.C.) independently determined the ranking of each restoration. When differences existed, both evaluators re-examined the subject together and reached a consensus.
In addition to ranking the presence or absence of marginal discoloration, each evaluator independently recorded the surfaces where discoloration occurred, as well as the extent to which the discoloration extended circumferentially. Consensus was not required on the surfaces or extent of the discoloration. The surfaces were tabulated to determine where discoloration was present.
We compared the treatments for differences in all measured parameters using Cochran-Mantel-Haenszel tests for ordered categorical outcomes. We computed percentage agreement for each area for each evaluation period to determine the level of agreement between evaluators before forced consensus.
|
RESULTS
|
|---|
Twelve men and 18 women were enrolled in the study. Their ages ranged from 30 to 75 years, with the mean age being 45 years. Of the subjects enrolled in the study, one man moved out of state before the six-month evaluation. All other subjects returned for all of the evaluations.
The percentage agreement between examiners before forced consensus was at least 83 percent for each area of each evaluation period (Table 2, page 453). The lesions to receive the Beautifil and Silux Plus restorations did not differ from each other in the amount of circumferential enamel present (P = .56), percentage surface area of dentin (P 
1.00) or lesion type (P = .25) (Table 3, page 453).
The treated teeth did not have significantly different retention (P 1.00), anatomical form (P 1.00), caries (P 1.00), staining (P 1.00), marginal discoloration (P 1.00), marginal adaptation (P 1.00), surface roughness (P 1.00) or sensitivity (P = .14) at baseline. At 36 months, the treated teeth did not have significantly different retention (P = .56), anatomical form (P = .65), caries (P = .37), staining (P 1.00), marginal discoloration (P = .26), marginal adaptation (P = .06), surface roughness (P = .37) or sensitivity (P = .17) (Table 4, page 453, Figure 1, page 454).
View this table:
[in this window]
[in a new window]
|
TABLE 4 PERCENTAGES OF RESTORATIONS RATED ‘ALFA’* FOR EACH EVALUATED CRITERION AT BASELINE, SIX, 18 AND 36 MONTHS (N = 39).
| |
View larger version (56K):
[in this window]
[in a new window]
|
Figure 1. Percentage of Alfa ratings at baseline (B) and at six, 18 and 36 months. See Table 1 for definitions of Alfa ratings. BF: Beautifil (Shofu, Kyoto, Japan). SP: Silux Plus (3M Dental Products, St. Paul, Minn.).
| |
In our study, retention did not seem to depend on whether the material chosen was giomer or microfilled resin.
Eleven teeth exhibited margins with discoloration. Seven of these margins were on teeth restored with Beautifil and four were on teeth restored with Silux Plus. On the Beautifil and Silux Plus restorations—46 percent and 40 percent, respectively—the surface that exhibited discoloration involved at least incisal surface (Table 5, page 454).
|
DISCUSSION
|
|---|
The most important criterion for restorations is that of retention. Van Meerbeek and colleagues7 have reported that using the air syringe to blow off some of the adhesive resin layer may reduce its thickness too much, decreasing its elastic buffer potential to relieve polymerization contraction stress. A thicker adhesive layer possibly will aid in absorbing masticatory forces, tooth flexure effects and thermal cycling shocks. All of these factors contribute to the retention of restorations. Others agree that an adequate thickness of adhesive resin is an important factor in developing a secure bond.8–10 One study has shown that the strength of bond is sometimes directly proportional and at other times inversely proportional to the thickness of the bonding material; in other words, it is material-dependent.11 In a study in which Fluorobond was used, excessive thinning occurred and retention was compromised.12 With those results in mind, we were careful not to thin the adhesive resin excessively. Subjects were pleased with the high retention rate of 91 percent after two years with the two materials used in this study (Figure 2). If retention is not achieved, no other criteria can be evaluated.
View larger version (89K):
[in this window]
[in a new window]
|
Figure 2. A. Class V lesions on teeth nos. 12 and 13 in a 70-year-old female subject. B. Restorations at baseline: tooth no. 12 restored with Silux Plus (3M Dental Products, St. Paul, Minn.) and no. 13 restored with Beautifil (Shofu, Kyoto, Japan). C. Restorations at six months. D. Restorations at 18 months. E. Restorations at 36 months.
| |
Dentin is a highly variable substrate that is subject to continuous changes in composition and microstructure owing to both physiological and pathological influences.13–15 Class V lesions resulting from abfraction/abrasion/erosion and other factors are unique in that they exhibit an increased amount of sclerotic dentin. Sclerotic dentin has been shown to exhibit low permeability and hypermineralization, resulting in a substrate that is less receptive to adhesive bonding techniques than normal dentin.16,17 Some studies have shown decreased retention in such lesions with older subjects,18 and others have shown that retention is not dependent on an increased amount of sclerotic dentin.2 Others have suggested that increasing the length of time that the sclerotic area is etched would be beneficial.19 In our study, retention did not seem to depend on whether the material chosen was giomer or microfilled resin.
Resin restorations are retained by micro-mechanical retention, while glass ionomer–containing restorations that use an acid-base reaction are retained by true chemical bonding of polyalkenoic acids to biological calcium.4 In the case of giomers that use PRG technology, the polyalkenoic acid reacts with the fluoroaluminosilicate glasses before inclusion in a dimethacrylate resin matrix. This allows for fluoride release from these materials but necessitates the use of bonding systems for adhesion to enamel and dentin.20 The combination of Beautifil with FL-Bond was shown not to result in any odontoblastic change or cell infiltration exhibiting pulpal inflammation in nonexposed monkey teeth that were evaluated histologically after 30 and 90 days.21 The use of these new materials has not resulted in significant short- or long-term postoperative sensitivity.22
We evaluated the restorations in our study in eight areas at each examination and observed no statistically significant differences among them. Researchers who evaluated giomers in comparison with conventional and resin-modified glass ionomer cements found giomers to have a significantly better surface finish than the other two types of cements.23
To meet the clinical portion of the Acceptance Program Guidelines for Dentin and Enamel Adhesive Materials, the ADA requires evaluation of a restorative material with "no greater incidence of clinical failures than 10 percent in retention and 10 percent in microleakage at 18 months."5 The guidelines also require that there be "no cavity preparation (including bevels) or features of macro-mechanical retention form (e.g., retention grooves, undercuts, etc.)." These conditions were met and, on the basis of the results of this study, both Beautifil and Silux Plus meet the clinical portion of the guidelines.
Ninety-one percent of the restored teeth that exhibited evidence of marginal discoloration did so on at least the occlusal-incisal interface of the enamel and restored surfaces. In vivo and in vitro studies have substantiated the finding that improved sealing of margins, when using resins or resin-modified glass ionomers, occurs with beveling of the occlusal-incisal enamel margins.24–26 In Class V restorations, it usually is the cervical margin that does not seal well; however, in our study, we found cervical discoloration in only 45 percent of the teeth with discolored margins.
|
CONCLUSIONS
|
|---|
Neither material was significantly different from each other in any of the eight areas evaluated. Both Beautifil and Silux Plus meet the ADA criteria for adhesive materials.
|
FOOTNOTES
|
|---|
Dr. Matis is a professor and the director, Clinical Research Section, Indiana University School of Dentistry, 1121 W. Michigan St., Indianapolis, Ind. 46202, e-mail "bmatis{at}iupui.edu". Address reprint requests to Dr. Matis.
Dr. Cochran is a professor and the director, Graduate Operative Program, Indiana University School of Dentistry, Indianapolis.
Dr. Carlson is a professor and the director, Comprehensive Care Clinic A, Indiana University School of Dentistry, Indianapolis.
Dr. Guba is an associate professor and the director, Clinical Assessment and Quality Assurance, Indiana University School of Dentistry, Indianapolis.
Mr. Eckert is a staff biostatistician, Indiana University School of Medicine, Indianapolis.
|
REFERENCES
|
|---|
- Lee WC, Eakle WS. Possible role of tensile stress in the etiology of cervical erosive lesions of teeth. J Prosthet Dent 1984;52:374–80.[Medline]
- van Dijken JW. Clinical evaluation of three adhesive systems in Class V non-carious lesions. Dent Mater 2000;16:285–91.[Medline]
- Folwaczny M, Loher C, Mehl A, Kunzelmann KH, Hinkel R. Tooth-colored filling materials for the restoration of cervical lesions: a 24-month follow-up study. Oper Dent 2000;25(4):251–8.[Medline]
- Yoshida Y, Van Meerbeek B, Nakayama Y, et al. Evidence of chemical bonding at biomaterial-hard tissue interfaces. J Dent Res 2000; 79(2):709–14.[Abstract/Free Full Text]
- American Dental Association, Council on Scientific Affairs. Revised American Dental Association Acceptance Program guidelines for dentin and enamel adhesive materials. Chicago: American Dental Association; 2001.
- Cvar JF, Ryge G. Criteria for the clinical evaluation of dental restorative materials. San Francisco: U.S. Department of Health, Education, and Welfare, U.S. Public Health Service; 1971. U.S. Public Health Service publication 790–244.
- Van Meerbeek B, Vargas M, Inoue S, et al. Adhesives and cements to promote preservation dentistry. Oper Dent 2001 (supplement 6): 119–44.
- Kemp-Scholte CM, Davidson CL. Complete marginal seal of Class V resin composite restorations effected by increased flexibility. J Dent Res 1990;69(6):1240–3.[Abstract/Free Full Text]
- Unterbrink GL, Liebenberg WH. Flowable resin composites as "filled adhesives": literature review and clinical recommendations. Quintessence Int 1999;30(4):249–57.[Medline]
- Lucena-Martin C, Gonzalez-Rodriguez MP, Ferrer-Luque CM, Robles-Gijon V, Navajas JM. Influence of time and thermocycling on marginal sealing of several dentin adhesive systems. Oper Dent 2001;26(6):550–5.[Medline]
- Zheng L, Pereira PN, Nakajima M, Sano H, Tagami J. Relationship between adhesive thickness and microtensile bond strength. Oper Dent 2001;26(1):97–104.[Medline]
- Platt JA, Winkler MM, Matis BA, Moore BK. Correlation of dentin adhesive laboratory and clinical performance at one year (abstract 1282). J Dent Res 1996;75(special issue):178.
- Pashley DH. Dentin: a dynamic substrate–a review. Scanning Microsc 1989;3(1):161–74.[Medline]
- Stanley HR, Pereira JC, Spiegel E, Broom C, Schultz M. The detection and prevalence of reactive and physiologic sclerotic dentin, reparative dentin and dead tracts beneath various types of dental lesions according to tooth surface and age. J Oral Pathol 1983;12(4):257–89.[Medline]
- Duke ES, Lindemuth J. Variability of clinical dentin substrates. Am J Dent 1991;4(5):241–6.[Medline]
- Burrow MF, Takakura H, Nakajima M, Inai N, Tagami J, Takatsu T. The influence of age and depth of dentin on bonding. Dent Mater 1994;10(4):241–6.[Medline]
- Tagami J, Hosoda H, Burrow MF, Nakajima M. Effect of aging and caries on dentin permeability. Proc Finn Dent Soc 1992;88 (supplement 1):149–54.
- Heymann HO, Sturdevant JR, Bayne S, Wilder AD, Sluder TB, Brunson WD. Examining tooth flexure effects on cervical restorations: a two-year clinical study. JADA 1991;122(6):41–7.
- Brackett MG, Dib A, Brackett WW, Estrada BE, Reyes AA. One-year clinical performance of a resin-modified glass ionomer and a resin composite restorative material in unprepared Class V restorations. Oper Dent 2002;27(2):112–6.[Medline]
- Yap AU, Pashley EL, Huang C, et al. The glass-ionomer phase in resin-based restorative materials. J Dent Res 2001;80(9):1808–12.[Abstract/Free Full Text]
- Gordan VV, Mjor IA. Short- and long-term clinical evaluation of post-operative sensitivity of a new resin-based restorative material and self-etching primer. Oper Dent 2002;27(6):543–8.[Medline]
- Sonoda H, Sasafuchi Y, Kitasako Y, Arakawa M, Otsuki M, Tagami J. Pulpal response to a fluoride-releasing all-in-one resin bonding system. Oper Dent 2002;27(3):271–7.[Medline]
- Yap AU, Mok BY. Surface finish of a new hybrid aesthetic restorative material. Oper Dent 2002;27(2):161–6.[Medline]
- Fritz UB, Finger WJ, Uno S. Resin-modified glass ionomer cements: bonding to enamel and dentin. Dent Mater 1996;12(3):161–6.[Medline]
- Cortes O, Garcia-Godoy F, Boj JR. Bond strength of resin-reinforced glass ionomer cements after enamel etching. Am J Dent 1993;6(6): 299–301.[Medline]
- Yap AU, Lim CC, Neo JC. Marginal sealing ability of three cervical restorative systems. Quintessence Int 1995;26(11):817–20.[Medline]
TOP
ABSTRACT
SUBJECTS, METHODS AND MATERIALS
