Jun 06, 2016

Enhancing Clinical Predictability & Efficiency of Direct Posterior Restorations Using Bulk Fill Composites

Wilson Kwong

650 West 41st Ave.

#218

Vancouver, BC, Canada V5Z2M9

778-228-6358

wjkwong@me.com

Abstract

Posterior composites have been an alternative to amalgam, but their use has beenaccompanied by greater placement-related challenges, including technique sensitive protocol, polymerization shrinkage, and shrinkage stress that result in marginal leakage, secondary caries, and postoperative sensitivity and pain for the patient. To eliminate the need for time consuming protocol and ensure long-term clinical predictability of direct posterior composite restorations, bulk fill composites have been introduced that can be placed in a single increment or layer of up to 4 mm, then light polymerized. This article reviews the time-saving and clinically predictable characteristics of bulk fill composites and presents two cases that demonstrate their efficient ease of use.

Introduction

Among the treatments most frequently performed by dentists today are direct posteriorcomposite restorations. Posterior composites have been an alternative to amalgam for at least 40 years, but their use has traditionally been accompanied by greater placement-related challenges and higher failure rates.1 Complications may be attributed, in part, to the consequences of not properly following the technique sensitive protocol involved with posterior composite placement, and/or the characteristics of the materials themselves.

Techniques for placing posterior composite restorations have usually involved placing and curing multiple layers of composite in increments of 2 mm or less, which is typically a long and complicated procedure.2-5 If not properly performed, complications from this type of incremental composite placement can include polymerization shrinkage and shrinkage stress that result in marginal leakage, secondary caries, and postoperative sensitivity and pain for the patient.4,5 In terms of the variety of composites available today, some may be considered suitable for universal indications (i.e., anterior and posterior restorations), while others are most appropriate for either anterior or posterior placement based on their chemical and material composition and, therefore, their esthetic, wear, and strength characteristics.6

Interestingly, however, researchers have found that it is a combination of restorativematerial placement and curing techniques, and material characteristics, that influence the success and longevity of direct posterior composite restorations.7-10 Therefore, to eliminate the need for time consuming protocol—yet ensure long-term clinical predictability (i.e., reduced shrinkage stress, elimination of microleakage, prevention of secondary caries, prevention of postoperative sensitivity)—numerous manufacturers have developed direct composites that can be placed in a single increment or layer of up to 4 mm, then fully cured (i.e., bulk fill composites). As a result of their specific material characteristics, available bulk fill composites (e.g., Tetric EvoCeram® Bulk Fill, Tetric EvoFlow® Bulk Fill, Ivoclar Vivadent; Venus® Bulk Fill, Heraeus; SonicFill, Kerr) help to eliminate the challenges associated with conventional posterior composite materials.

For example, the ability to be cured to a depth of 4 mm eliminates the need for time consuming and technique sensitive layering, and better handling properties facilitate enhanced marginal adaptation to preparations. Additionally, the low polymerization shrinkage stress of bulk fill composites reduces microleakage, postoperative sensitivity, and secondary caries.11,12

The following cases demonstrate the time-saving and clinically predictable characteristics of bulk fill composites, as well as their efficient ease of use. For the cases presented, one particular bulk fill composite (i.e., Tetric EvoCeram Bulk Fill, Tetric EvoFlow Bulk Fill) was selected based on its handling, esthetic, and material/strength properties.8,13,14

Case Presentation #1

A patient presented with caries on the mesial aspect of the upper right second molar, tooth #2, which was confirmed radiographically (Figure 1). Treatment was planned to remove the caries and place a mesial-occlusal (MO) direct composite restoration, as well as examine grooves on the adjacent teeth.

In the past, posterior teeth would have been treated with simple amalgam or compositerestorations, or indirect gold, porcelain, or laboratory-fabricated restorations.15 However, given the small size and location of the defect, a small cavity preparation would be ideal using the most conservative adhesive bonding techniques possible. A bulk fill composite containing a patented light-initiator (i.e., Tetric EvoCeram Bulk Fill; Ivocerin®) was selected based on the deeper and more efficient depth-of-cure and shorter curing time provided.13

The patient was anesthetized, and a rubber dam was placed to ensure proper and complete isolation. Caries was exposed, and a caries detection solution was placed. Caries removal was completed, and the preparation was cleansed with a 2% chlorhexidine scrub via syringe and brushes to remove debris and decrease the bacterial load, as well as condition the dentin preparation for the MO restoration (Figure 2).16,17

The teeth were rinsed and dried, and a matrix band (Palodent) and V-Ring (Dentsply) were placed. A total etch technique was used, and the enamel and dentin of the preparation were etched with a 30% hydrophosphoric acid for 20 and 15 seconds, respectively (Figure 3), and then vigorously rinsed for 10 to 15 seconds. The preparation was lightly dried with a warm air tooth dryer (Adec), leaving the dentin slightly moist. Additionally, the adjacent teeth were etched to subsequently enable bonding and sealing of the grooves using Tetric EvoFlow Bulk Fill and polymerization.

A universal adhesive indicated for use on both dry and moist dentin (Adhese® Universal, Ivoclar Vivadent) was scrubbed to the preparation and light-cured for 10 seconds using an LED curing light (Bluephase® Style, Ivoclar Vivadent) (Figure 4).

Then, the restoration was completed using a single 4-mm increment of the nano-hybrid bulk fill composite (Tetric EvoCeram Bulk Fill/IVA Shade). The selected bulk fill composite demonstrates an enamel-like translucency of 15%, which would contribute to an “invisible” blending of the restoration with surrounding natural tooth structure. Available in three universal shades (e.g., IVA for slightly reddish teeth; IVB for slightly yellowish teeth; and IVW for deciduous fillings or light-colored teeth), the selected bulk fill composite is also highly radiopaque, which is ideal for identification of radiographs.

The bulk fill composite was placed into the preparation, a step that was enhanced by the material’s layered silicates. The bulk fill composite’s smooth consistency adapted nicely to the preparation walls, and the singular increment was easily contoured and sculpted using a conventional composite placement instrument (OptraSculpt, Ivoclar Vivadent). No additional expensive equipment was necessary.

The restoration was then cured fully for 10 seconds using an LED curing light. As a result of the photo-initiator contained in the selected bulk fill composite, the 4 mm increment could be thoroughly cured in 10 seconds using an LED curing light with a minimum output greater than 1,000 mW/cm2.

The band and ring were removed, and the occlusion adjusted using finishing diamonds.The restoration(s) was finished using carbide-fluted finishing burs (3M, ESPE, Sof-Lex), polished utilizing a one-step, high-gloss polishing system (Optrapol, Ivoclar Vivadent), flossed and revealed (Figure 5). Interestingly, because the selected bulk fill composite (Tetric EvoCeram Bulk Fill) contains two types of glass fillers with different mean particle sizes, restorations withstand posterior wear well, yet also demonstrate ideal polishing properties.13 The marginal seal of the MO restoration was the confirmed radiographically (Figure 6).

Case Presentation #2

A 19-year-old male patient presented with caries on the mesial aspect of the upper rightsecond molar that was confirmed radiographically (Figure 7). Treatment was planned to remove the caries and place a mesial direct composite restoration, as well as examine the distal aspect of neighboring tooth #16.

The patient was anesthetized, and a rubber dam was placed to ensure proper and complete isolation. Caries was removed, caries detection solution placed to ensure 100% removal, and the tooth prepared for a mesial restoration (Figure 8). The preparation was then cleansed with a 2% chlorhexidine scrub using a syringe and brushes to remove debris created during preparation.

The teeth were rinsed and dried, and in this case, a matrix band, wedge, and ring were placed. The teeth were selectively etched with phosphoric acid on the enamel margins only, thoroughly rinsed, and then dried. A universal adhesive was applied to the preparation (Figure 9), and it was rubbed vigorously onto the dentin using the application tip and then onto the enamel, after which it was blown thin and light-cured for 10 seconds using an LED curing light.

To complete the restorations, Tetric EvoCeram Bulk Fill composite (i.e., IVA shade) was placed into the preparation in a single increment (Figure 10), then shaped and contoured to create the proper anatomy using a composite placement instrument. This bulk increment was lightcured for 10 seconds from each of the proximal aspects (Figure 11).

The band, wedge, and ring were removed and the occlusion adjusted using finishing instruments (e.g., Sof-Lex, 3M ESPE) (Figure 12). A final polish was performed using a series of grey, green, and pink polishing points and brushes (Astropol, Ivoclar Vivadent) (Figures 13), after which the rubber dam was removed and the bite verified and adjusted, as necessary (Figures14 and 15).

Conclusion

To eliminate the need for time consuming protocol and ensure long-term clinical

predictability of direct posterior composite restorations, bulk fill composites can be placed in a single increment or layer of up to 4 mm, then fully cured. However, as important as placement and curing techniques are to the success and longevity of posterior restorations, so too are material characteristics. Therefore, when choosing bulk fill composites for direct posterior restorations, it behooves dentists to choose those materials that will truly be time-saving, efficient, and most importantly, clinically predictable. For the cases presented here, the author

choose a nano-hybrid bulk fill composite (Tetric EvoCeram Bulk Fill, Tetric EvoFlow Bulk Fill) based on its low polymerization shrinkage; low shrinkage stress; depth of cure; esthetics, handling, and radiopacity; and overall clinical predictability.

References

1. Sarrett DC. Clinical challenges and the relevance of materials testing for posterior compositerestorations. Dent Mater. 2005 Jan; 21 (1):9-20.

2. Wieczkowski G Jr, Joynt RB, Klockowski R, Davis EL. Effects of incremental versus bulk fill technique on resistance to cuspal fracture of teeth restored with posterior composites. J Prosthet Dent.1988;60(3):283-287.

3. Fabianelli A, Sgarra A, Goracci C, et al. Microleakage in class II restorations: open vs closed centripetal build-up technique. Oper Dent. 2010;35(3):308-313.

4. Giachetti L, Scaminaci Russo D, Bambi C, Grandini R. A review of polymerization shrinkage stress: current techniques for posterior direct resin restorations. J Contemp Dent Pract. 2006 Sep 1;7 (4):79-88.

5. Cheung GS. Reducing marginal leakage of posterior composite resin restorations: a review of clinical techniques. J Prosthet Dent. 1990 Mar;63(3):286-8.

6. Ferracane JL. Resin composite--state of the art. Dent Mater. 2011 Jan;27(1):29-38. Epub 2010 Nov 18.

7. Campodonico CE, Tantbirojn D, Olin PS, Versluis A. Cuspal deflection and depth of cure in resin-based composite restorations filled by using bulk, incremental and transtooth-illumination techniques. J Am Dent Assoc. 2011 Oct;142(10):1176-82.

8. Utterodt A, Rist AC, Eck M, Schaub M. Polymerization shrinkage stress and flexural strength of nano-composites. 42nd annual meeting of IADR-Continental: 2007.

9. Van Ende A, De Munck J, Mine A, Lambrechts P, Van Meerbeek B. Does a low shrinking composite induce less stress at the adhesive interface? Dent Mater. 2010;26(3):215-22.

10. Souza-Junior EJ, de Souza-Régis MR, Alonso RC, de Freitas AP, Sinhoreti MA, Cunha LG. Effect of the curing method and composite volume on marginal and internal adaptation of composite restoratives. Oper Dent. 2011 Mar-Apr;36(2):231-8. Epub 2011 Jun 24.

11. Van Ende A, De Munck J, Van Landuyt KL, et al. Bulk-filling of high C-factor posterior cavities: effect on adhesion to cavity-bottom dentin. Dent Mater. 2013 ;29(3):269-277.

12. Moorthy A, Hogg CH, Dowling AH, et al. Cuspal deflection and microleakage in premolar teeth restored with bulk-fill flowable resin-based composite base materials. J Dent. 2012;40(6): 500-505.

13. Tetric EvoCeram Bulk Fill: The bulk composite without compromises. Scientific

Documentation. Schaan, Liechtenstein: Ivoclar Vivadent; 2011: 1-20.

14. Roggendorf MJ, Krämer N, Appelt A, Naumann M, Frankenberger R. Marginal quality of flowable 4-mm base vs. conventionally layered resin composite. J Dent. 2011 Jul 27. [Epub ahead of print].

15. Roulet JF. Benefits and disadvantages of tooth-coloured alternatives to amalgam. J Dent. 1997 Nov;25(6):459-73.

16. Ruse ND, Smith DC. Adhesion to bovine dentin--surface characterization. J Dent Res. 1991 Jun;70(6):1002-8.

17. Leitune VC, Portella FF, Bohn PV, Collares FM, Samuel SM. Influence of chlorhexidine application on longitudinal adhesive bond strength in deciduous teeth. Braz Oral Res. 2011 Sep- Oct;25(5):388-92.

Figure Captions

Figure 1. A preoperative radiograph revealed mesial decay in the upper right second molar, tooth #17.

Figure 2. Following rubber dam placement, restorative procedures were performed to remove the decay, and prepare and condition the tooth for restoration.

Figure 3. Following placement of a Palodent matrix and Dentsply V-Ring, the preparation for tooth #2 was etched according to the total etch technique using 30% hydrophosphoric acid. The other teeth were etched to subsequently enable bonding and sealing of the grooves using Tetric EvoFlow Bulk Fill.

Figure 4. A universal adhesive was applied to the preparation and light-cured, after which a single increment of a nano-hybrid bulk fill composite (Tetric EvoCeram Bulk Fill) was placed to complete the restoration.

Figure 5. The completed Tetric EvoCeram and Tetric EvoFlow bulk fill restorations were

finished and polished.

Figure 6. A post-treatment radiograph confirmed the excellent radiopacity and marginal seal of the bulk filled restorations.

Figure 7. Preoperative radiograph revealing mesial decay in the upper right second molar of a 19-year-old male patient.

Figure 8. After complete caries removal, the tooth was prepared for a mesial direct composite restoration.

Figure 9. A universal adhesive was rubbed vigorously onto the dentin using the application tip and then onto the enamel of the preparation.

Figure 10. Tetric EvoCeram Bulk Fill composite in Vita shade A (i.e., IVA shade) was placed into the preparation in a single increment.

Figure 11. After shaping and contouring to create the proper anatomy, the bulk filled restoration was light-cured for 10 seconds.

Figure 12. The occlusion was adjusted using finishing discs (e.g., Sof-Lex, 3M ESPE).

Figure 13. A series of Astropol grey, green, and pink polishing points (Astropol0 and brushes were used for final polishing.

Figure 14. Post-treatment view of the completed Tetric EvoCeram Bulk Fill restoration after finishing and polishing.

Figure 15. A post-treatment radiograph confirmed the excellent radiopacity and marginal seal of the bulk filled restoration.

Click link below for images:

https://www.dropbox.com/l/sh/t2F5z38roCXrfjZUTsbFiq