fluorescence of composite resins clinical considerations.original

Fluorescence of Composite Resins: Clinical Considerations

Luis Guilherme Sensi, DDS, MS, PhD1

Fabiano Carlos Marson, DDS, MS, PhD1

Tayanna Hawerroth Roesner, DDS2

Luiz Narciso Baratieri, DDS, MS, MSD, PhD3

Sylvio Monteiro Junior, DDS, MS, PhD3

QDT 2006 1

he main objective of restorative dentistryis to replace damaged tooth structurewith materials that posses biological,

physical, and functional properties similar to thoseof natural teeth.1 The esthetic restoration of theanterior dentition presents one of the greatestchallenges in daily practice since any slight dispar-ity can be immediately noticed every time the pa-tient smiles.2,3 Numerous composite systems havebeen developed in recent years offering a multi-tude of shades, translucencies, opacities and ef-fects, and when used in conjunction with innova-tive placement techniques, they make possiblethe fabrication of restorations that faithfully emu-late the polychromatic variations and optical char-acteristics of natural teeth.4–16 However, in order to

achieve a truly natural-appearing direct compositerestoration, a clinician must have comprehensiveknowledge of the optical characteristics for bothnatural teeth and composite resins, and thoroughtraining in the proper selection and application ofcurrent restorative systems.11,16 The optical charac-teristics of natural teeth are determined by the in-teraction of light with dentin, enamel, and the un-derlying pulp, and include varying degrees oftranslucency and opacity of enamel and dentin, ofopalescent and iridescent effects, and of fluores-cence.7,9,10,17,18

FLUORESCENCE OF NATURAL TEETH ANDCOMPOSITE RESTORATIONS

In dentistry it has been traditionally assumed thatfluorescence is the absorption of energy in thenonvisible spectrum (ie, ultraviolet light) and,when in the presence of ultraviolet illumination (ie,black light), the emission of longer wavelengthsvisible in the white-bluish spectrum (ie,glow).1,7,9,18–20 Natural teeth emit a strong blue fluo-rescence when exposed to black light (Fig 1). Thisproperty makes natural teeth look brighter andmore alive, and the reproduction of this character-istic has a dramatic effect on the level of vitalityand brightness exhibited by restorations.18–20 When

1Graduate student, Operative Dentistry, Federal University ofSanta Catarina, Florianópolis, Santa Catarina, Brazil.

2Private practice, Florianópolis, Santa Catarina, Brazil.3Professor, Department of Operative Dentistry, Federal Uni-versity of Santa Catarina, Florianópolis, Santa Catarina,Brazil.

Correspondence to: Dr Luis Guilherme Sensi, Av. João PioDuarte Silva n. 404, Apto. 101, Bl. Juriti, Córrego Grande,Florianópolis, Santa Catarina, Brazil 88037-001. E-mail:[email protected]

T

SENSI ET AL

QDT 20062

measured with fluorescence spectrophotometers,the fluorescence spectrum of natural enamel pre-sented luminescent peaks at 450 nm,21 while thefluorescence spectrum of dentin, whose intensityis three times higher than that of enamel,21 pre-sented peaks at 440 nm19 or 430 nm.

The fluorescence of composite resin restora-tions is independent of their perceived colorunder white light1 and, though minimally percepti-ble under normal viewing conditions, it is clinicallysignificant because truly esthetic restorationsshould match the color of natural teeth in daylightas well as under different light sources.22 This issueis especially relevant when treating patients in thepublic eye (eg, actors, performers, musicians,models, and newscasters) or those who often goto the theater, dance clubs, and other nightspotswhere they can be exposed to black light.23 Underthis source of illumination, restorations fabricatedwith nonfluorescent materials will appear as blackareas/spots in the smile line, causing embarrass-ment not only to the patients, but also to the clini-cians, who might be asked to substitute suchrestorations for fluorescent ones.24 Therefore,when designing restorations, clinicians shouldtake into consideration form and color reproduc-tion as well as the emulation of other intrinsiccharacteristics of natural teeth, creating restora-tions in keeping with the personality, expecta-tions, life-style, and occupation of their patients.

When trying to mimic nature, restorative mate-rials should ideally have fluorescent propertiessimilar to those of natural teeth.25 Most dental ma-terial manufacturers have overlooked this impor-

tant property, even though esthetic materialsshould simulate the fluorescence of natural teethto avoid the problem of metamerism.24

OBSERVATIONS OF RESTORATIVE MATERIAL

The fluorescence of natural teeth and compositeresins can be easily tested and compared with theaid of a black light.20 Such observations can assistthe practitioner to select the materials best suitedfor enhanced esthetic results. When observingcomposite resin disks under ultraviolet illuminationin a dark environment, the different fluorescentproperties of each restorative system can be seen.Using a natural tooth as a point of reference (Fig2), the fluorescence of composite resins can bequalitatively classified as absent (low fluorescence);ideal (near natural-tooth fluorescence); and exag-gerated (more fluorescence than natural tooth).

Figure 3 shows composite resin disks that pre-sented low levels of fluorescence and Fig 4 showsexamples of how restorations fabricated withthese composites look under black-light illumina-tion. Composite resin disks that presented fluores-cence similar to that of natural tooth are shown inFig 5 and examples of how restorations fabricatedwith them appear under black-light illuminationare shown in the Fig 6. Figure 7 shows compositeresin disks that presented exaggerated fluores-cence and Fig 8 shows examples of how restora-tions fabricated with these composites look underblack-light illumination.

Fig 1 Natural teeth present a strong blue fluorescence when ex-posed to black light.


3QDT 2006

Fig 2 Extracted tooth illuminatedunder black light can serve as a pointof reference for natural fluorescence.

Fig 3 Composite resin disks thatpresented low levels of fluorescence:(a) Durafill, (b) Charisma, (c) Glacier,(d) Micronew, (e) Palfique Estelite, (f)Matrixx (Microfill), (g) Filtek Supreme,(h) Venus, (i) Filtek Z250.

Fig 4 Restorations fabricated withlow-fluorescent composites, underblack-light illumination: (a) Charisma,(b) Filtek Z250, (c) Filtek Supreme,(d) Venus.

Fig 5 Composite resin disks thatpresented fluorescence similar tothat of natural tooth: (a) Renamel, (b)Enamel Plus, (c) Amelogen, (d) 4Seasons, (e) Vit-l-scence.

Fig 6 Restorations fabricated withhigh-fluorescent composites, underblack-light illumination: (a) 4 Seasons,(b) Vit-l-scence, (c) Renamel, (d)Amelogen.

Fig 7 Composite resin disks thatpresented high levels [Au: Edit re-tain meaning?] of fluorescence: (a)Herculite XRV, (b) TPH, (c) Miris, (d)Matrixx, (e) Tetric Ceram, (f) Esthet-X.

Fig 8 Restorations fabricated withhigh-fluorescent composites, underblack light illumination: (a) Miris, (b)Herculite XRV, (c) Esthet-X, (d) TetricCeram.

2

3

5

4

6

8

7

A B C D E

F G H I A B C C

A B C D EA B C

A B C

A B C

D

A B C D

QDT 20064

SENSI ET AL

Table 1 summarizes the observed resin com-posites and their fluorescence classification. Theseobservations have been corroborated by results ofrecent research that determined the quantitativedifferences in fluorescence among some of thecited composites using a color-measuring spec-trophotometer.19,21

INCREMENTAL LAYERING ISSUES

It has been stated that in order to create a restora-tion that truly resembles the natural dentition, ahigh-fluorescence dentin material and a low-fluo-rescence enamel material would be required.9

However, unlike natural teeth where the dentin isresponsible for the greater part of the fluores-cence,21 in composite restorations the fluores-cence is primarily defined by the final enamellayer. If the dentin portion of a restoration is builtup with a high-fluorescence material (Fig 9) and

subsequently covered with a low-fluorescence ma-terial, the result would be a nonfluorescentrestoration (Fig 9), as the last nonfluorescent layercovers and blocks the fluorescence of the underly-ing layers. It has been demonstrated that even avery thin layer of a nonfluorescent surface sealantcan block the fluorescence of composite resins.22

Conversely, if the dentin portion of a restoration isbuilt up with a nonfluorescent material (Fig 10)and covered with a fluorescent material, the resultwould be a fluorescent restoration (Fig 10), as theoverlying layer is only slightly influenced by thenonfluorescence of the underlying layers. Whenboth dentin and enamel composites are fluores-cent, they can be built up in such a way to achievea fluorescence similar to that of the natural teeth.20

Therefore, clinicians have to keep in mind that,fluorescence should be present in at least theenamel composite resin, and that ideally, both thedentin and enamel composite resins should pre-sent fluorescence.

Table 1 Classification of Composite Resins According to Particle Size, Fluorescence, and Manufacturer

Composite resins Filler Fluorescence Manufacturer

4 Seasons Microhybrid Ideal Ivoclar Vivadent

Amelogen Microhybrid Ideal Ultradent

Charisma Microhybrid Absent Heraeus Kulzer

Durafill Microfill Absent Heraeus Kulzer

Enamel Plus Microhybrid Ideal Micerium

Esthet-X Microhybrid Exaggerated Dentsply

Filtek Supreme Nano-particle Absent 3M ESPE

Filtek Z-250 Microhybrid Absent 3M ESPE

Glacier Microhybrid Absent SDI

Herculite XRV Microhybrid Exaggerated Kerr

Matrixx (1) Microhybrid Exaggerated Discus Dental

Matrixx (2) Microfill Absent Discus Dental

Micronew Microfill Absent Bisco

Miris Microhybrid Exaggerated Coltène-Whaledent

Palfique Estelite Microhybrid Absent Tokuyama

Renamel Microhybrid Ideal Cosmedent

Tetric Ceram Microhybrid Exaggerated Ivoclar Vivadent

TPH Microhybrid Exaggerated Dentsply

Venus Microhybrid Absent Heraeus Kulzer

Vit-l-scence Microhybrid Ideal Ultradent

CASE PRESENTATION

A 24-year-old male actor/performer presentedwith an unsatisfactory Class IV restoration of themaxillary left central incisor (Fig 11). His complaintwas that the restoration appeared black when hewas on the stage and caused him embarrassment.The nonfluorescence of the restoration was con-firmed when using a black light to illuminate hissmile (Fig 12). Despite the fact that the restorationdid not present fluorescence, it was well adaptedand adjusted, exhibiting a satisfactory colormatch, but lacking in surface texture, anatomicmorphology, and luster (Fig 13).

A silicone-putty matrix was made to facilitatethe reconstruction of the palatal surface, minimizethe amount of finishing, and allow the develop-ment of an accurate incisal-edge contour.3 Afteranesthesia was administered, the restoration wasremoved, and as no bevel was present, the frac-ture line was smoothed with a polishing disk (Su-persnap, Shofu) (Figs 14 and 15). Shade selectionwas performed before field isolation to prevent in-accurate color matching due to tooth dehydration.It was begun using a shade tab (Fig 16) and com-pleted after the positioning and polymerization ofsmall increments of the selected composites over

the remaining tooth structure. This is an essentialstep, as the shade of composite resins changesafter polymerization.26 A mock-up was prepared toconfirm composite resin selection (Fig 17). Anynecessary corrections were charted on a color mapused to diagram the selected shades and tints andtheir appropriate positioning so that they could beaccurately applied at the restorative stage (Fig 18).Field isolation was accomplished with a lip andcheek retractor, Teflon tape, and retraction cord. A37% phosphoric acid (Ultratech, Ultradent Prod-ucts) was applied to enamel and dentin for 15 sec-onds (Fig 19), rinsed with an air-water spray for thesame amount of time, and slightly dried with amild air stream to prevent dentin dehydration. Aone-bottle adhesive system (PQ1, Ultradent Prod-ucts) was applied according to the manufacturer’sinstructions (Fig 20) and light cured for 20 seconds(Fig 21). The initial artificial palatal enamel layer ofPearl Frost–shaded hybrid–composite resin (Amel-ogen, Ultradent Products) was positioned on thesilicone matrix with a spatula and smoothed with asable brush (no. 4, National Keystone), accordingto the direction of the fracture (Fig 22). This layerwas no thicker than 2 mm buccolingually to offerbetter control over the desired anatomic stratifica-tion and to ensure complete polymerization.

QDT 2006 5


Fig 9 (a) Dentin portion of the restoration was built upwith a high-fluorescent composite. (b) Nonfluorescentrestorations result form a low-fluorescent composite ap-plied over the high-fluorescent layer.

Fig 10 (a) Dentin portion of this restoration was builtup with a nonfluorescent composite. (b) Enamel layerwas reconstructed with a fluorescent composite result-ing in a fluorescent restoration. The fluorescence ofcomposite restorations is mainly defined by the overly-ing enamel layer, rather than the dentin layer.

A B A B

QDT 20066

SENSI ET AL

CASE PRESENTATION

1514 16

1817

11

13

12

Fig 11 Unsatisfactory Class IV restoration of themaxillary left central incisor.

Fig 12 Under black-light illumination, the restora-tion appears black, compromising the esthetics ofthe smile.

Fig 13 Well adapted and adjusted restorationpresenting a satisfactory color match but lackingin surface texture, anatomic morphology, luster,and fluorescence.

Fig 14 After removing the restoration, the fracture line was smoothed with a finishing disk as no bevel waspresent.

Fig 15 Note that no bevels were placed after restoration removal.

Fig 16 Initial shade selection with the aid of a shade tab.

Fig 17 Mock-up to confirm shade selection.

Fig 18 Color map was used to diagram the selected shades and tints and their appropriate positioning foraccurate application at the restorative stage.

Palatal Enamel - Pearl Frost

Fracture Line - A2 Opaque

Dentin - A2 Opaque

Enamel - A2

Craze Lines - White tint

Buccal Enamel - Pearl Frost

Once the silicone matrix was positioned, thecomposite resin was carefully adapted to the in-ternal tooth structure (Fig 23) and then light curedfor 20 seconds. After removing the matrix, thecomposite was light cured through the palatal sur-face for another 20 seconds. The buccal and distalviews of the artificial palatal enamel layer demon-strate the available space for the subsequent lay-ers (Figs 24 and 25).

To blend the composite restoration into thetooth structure and to disguise the fracture line,an increment of a high-chroma–shaded compositeresin (A2-O, Amelogen, Ultradent Products) waslightly feathered between the palatal enamel layerand the buccal enamel (Figs 26 and 27). The artifi-cial dentin layer was then reconstructed with ahigh-chroma–shaded composite resin (A2-O,Amelogen) and dentin lobes were sculpted with a

QDT 2006 7


2423 25

19 20 21 22

Fig 19 Application of a 37% phosphoric-acid gel for 15 seconds following field isolation.

Fig 20 Application of one-bottle adhesive to the etched surface with a disposable brush.

Fig 21 Adhesive was light cured for 20 seconds.

Fig 22 Initial artificial palatal enamel layer was positioned on the silicone matrix with a spatula and smoothedwith a sable brush, according to the fracture direction.

Fig 23 Careful adaptation of the artificial palatal enamel layer to the internal tooth structure prior to polymer-ization.

Fig 24 Artificial palatal enamel layer after polymerization.

Fig 25 In this distal view, note the space available for the subsequent layers.

composite-contouring instrument (POCS, Cosme-dent) (Fig 28).

The artificial enamel was built up in two compos-ite layers to impart a more realistic depth of color.

After application of a thin artificial internal enamellayer (A2, Amelogen), horizontal grooves were cre-ated with a razor-sharp composite instrument(96043, Almore International) (Figs 29 and 30).

QDT 20068

SENSI ET AL

Fig 26 Imperceptible fracture line. A high-chroma–shaded composite resin was used to blend the compositerestoration into the tooth structure.

Fig 27 Light feathering of the high-chroma–shaded composite resin between the palatal enamel layer andthe buccal enamel.

Fig 28 Positioning of artificial dentin layer and sculpting of dentin lobes with a composite-contouring instru-ment.

Fig 29 Creation of horizontal grooves with a razor-sharp composite instrument, after application of a thin arti-ficial internal enamel layer.

Fig 30 Distal view of created horizontal grooves.

Fig 31 Application of white tint on horizontal grooves to mimic the craze lines on the adjacent tooth.

Fig 32 Completed restoration after application of the artificial buccal enamel layer and prior to the finishingand polishing procedures.

26 27 28 29

30 31 32

These horizontal grooves provided room for theapplication of a white tint (Kolor+Plus, Kerr Sybron)(Fig 31) to mimic craze lines present on the adja-cent tooth. The artificial buccal enamel layer wasrecreated with a Pearl Frost–shaded hybrid–com-posite resin (Amelogen), applied and contouredwith a long-bladed instrument (IPCL, Cosmedent)and smoothed with a no. 4 artist brush.

The restoration was additionally light curedthrough an oxygen-inhibitor gel (De-Ox, UltradentProducts) for 1 minute from both the buccal andpalatal aspects. Figure 32 shows the completedrestoration prior to the finishing and polishingprocedures. Excess composite was removed, andthe occlusion was checked and adjusted beforethe patient was dismissed.

At a subsequent appointment, the surface tex-ture, anatomic morphology, and luster were de-fined. Initial contouring was performed with along, tapered extra-fine diamond bur (Fig 33) to

recreate the depression areas present on the con-tralateral incisor. These areas were polished with asilicon rubber point (Flexi-Point, Cosmedent) tominimize undesired accentuation (Fig 34). Thebuccal, proximal, and incisal angles were finishedwith an extra-fine aluminum oxide disk (Flexi-Discs, Cosmedent) (Fig 35). Surface texture wasrecreated with an extra-fine straight-edge dia-mond bur (Fig 36) to produce horizontal linesfrom the cervical third to the incisal third of thecrown (Fig 37). A buff wheel (Flexi-Buff, Cosme-dent) was used with a polishing paste (Enamelize,Cosmedent) to impart light reflectance and a highluster, while maintaining the established textureand surface morphology (Fig 38). Silver powderwas used to highlight teeth morphology andcheck the final texture (Fig 39). Figures 40 to 42show the final polished restoration. The patient’ssmile was again illuminated under black light toobserve the achieved fluorescence (Fig 43).

QDT 2006 9


Fig 33 Reproduction of depression areas on the contralateral incisor with a long, tapered extra-fine diamondbur.

Fig 34 Polishing with a silicon-rubber point to eliminate undesired accentuation.

Fig 35 Finishing of buccal, proximal, and incisal angles with an extra-fine aluminum oxide disk.

Fig 36 Creation of surface texture. An extra-fine straight-edge diamond bur was used to produce horizontallines from the cervical third to the incisal third of the crown.

33 34 35 36

QDT 200610

SENSI ET AL

3837 39

40 41

Fig 37 Horizontal lines prior topolishing.

Fig 38 Buff wheel used with pol-ishing paste to impart light re-flectance and a high luster whilemaintaining the established tex-ture and surface morphology.

Fig 39 Silver powder used tohighlight teeth morphology andcheck the final achieved texture.

Fig 40 Mesial view of the finalrestoration showing surface de-tails, contour, and texture.

Fig 41 Distal view of the finalrestoration. Note the harmoniousintegration despite the absence ofany bevel on enamel.

Fig 42 Postoperative appearanceof the finished and polishedrestoration.

Fig 43 Achieved fluorescenceunder black-light illumination.

42

43

SUMMARY AND CONCLUSION

Fluorescence is an important optical property ofnatural teeth and its reproduction is necessarywhen highly esthetic restorations are desired. Try-ing to match natural fluorescence with compositeresins can become a complicated task of trial anderror, most often because of inadequate materialselection. Knowledge of fluorescent characteris-tics of the available composite resins is imperativeuntil proper fluorescence is present in everyrestorative system.

REFERENCES

1. Chu SJ, Ahmad I. Light dynamic properties of a synthetic,low-fusing, quartz glass-ceramic material. Pract ProcedAesthet Dent 2003;15:49–56.

2. Fahl N Jr. The aesthetic composite anterior single crownrestoration. Pract Periodontics Aesthet Dent1997;9:59–70.

3. Peyton JH. Finishing and polishing techniques: Directcomposite resin restorations. Pract Proced Aesthet Dent2004;16:293–298.

4. Buda M. Form and color reproduction for composite resinreconstruction of anterior teeth. Int J PeriodonticsRestorative Dent 1994;14:34–47.

5. Dietschi D. Free-hand composite resin restorations: A keyto anterior aesthetics. Pract Periodontics Aesthet Dent1995;7:15–25.

6. Fahl N Jr, Denehy GE, Jackson RD. Protocol for pre-dictable restoration of anterior teeth with compositeresins. Pract Periodontics Aesthet Dent 1995;7:13–21.

7. Magne P, Holz J. Stratification of composite restorations:Systematic and durable replication of natural aesthetics.Pract Periodontics Aesthet Dent 1996;8:61–68.

8. Dietschi D, Schonenberger A. Layering techniques andaesthetic anterior restorations: What’s really new? PractPeriodontics Aesthet Dent 1996;8:279–281.

9. Vanini L. Light and color in anterior composite restora-tions. Pract Periodontics Aesthet Dent 1996;8:673–682.

10. Dietschi D. Free-hand bonding in the esthetic treatmentof anterior teeth: Creating the illusion. J Esthet Dent1997;9:156–164.

11. de Araujo EM Jr, Baratieri LN, Monteiro S Jr, Vieira LC, deAndrada MA. Direct adhesive restoration of anteriorteeth: Part 1. Fundamentals of excellence. Pract ProcedAesthet Dent 2003;15:233–240.

12. de Araujo EM Jr, Baratieri LN, Monteiro S Jr, Vieira LC, deAndrada MA. Direct adhesive restoration of anteriorteeth: Part 2. Clinical protocol. Pract Proced Aesthet Dent2003 Jun;15(5):351–357.

13. de Araujo EM Jr, Baratieri LN, Monteiro S Jr, Vieira LC, deAndrada MA. Direct adhesive restoration of anteriorteeth: Part 3. Procedural considerations. Pract ProcedAesthet Dent 2003;15:433–437.

14. Jackson RD. Understanding the characteristics of naturallyshaded composite resins. Pract Proced Aesthet Dent2003;15:577–585.

15. Culp L. Replicating natural dentition with composite resin.Pract Proced Aesthet Dent 2004;16:27–30.

16. Terry DA, Leinfelder KF. An integration of composite resinwith natural tooth structure: The Class IV restoration.Pract Proced Aesthet Dent 2004;16:235–242.

17. Winter R. Visualizing the natural dentition. J Esthet Dent1993;5:102–117.

18. Fondriest J. Shade matching in restorative dentistry: Thescience and strategies. Int J Periodontics RestorativeDent 2003;23:467–479.

19. Lee YK, Lu H, Powers JM. Fluorescence of layered resincomposites. J Esthet Restor Dent 2005;17:93–100.

20. Villarroel M, Jorquera C, Gomes OMM, Gomes JC. Fluo-rescence: A contribution to the natural vitality of humantooth [In Portuguese]. Rev Ibero-Am Odontol Estet Dent2004;3:397–406.

21. Monsenego G, Burdairon G, Clerjaud B. Fluorescence ofdental porcelain. J Prosthet Dent 1993;69:106–113.

22. Lee YK, Lu H, Powers JM. Effect of surface sealant andstaining on the fluorescence of resin composites. J Pros-thet Dent 2005;93:260–266.

23. Miller MB. The elusive nature of fluorescence. PractProced Aesthet Dent 2003;15:84.

24. Miller M. Composite resin fluorescence. J Esthet RestorDent 2004;16:335.

25. Panzeri H, Fernandes LT, Minelli CJ. Spectral fluorescenceof direct anterior restorative materials. Aust Dent J1977;22:458–461.

26. Lee YK, Lim BS, Rhee SH, Yang HC, Powers JM. Colorand translucency of A2 shade resin composites after cur-ing, polishing and thermocycling. Oper Dent2005;30:436–442.

QDT 2006 11


fluorescence of composite resins clinical considerations.original

Documents